diff options
Diffstat (limited to '2510')
226 files changed, 4366 insertions, 0 deletions
diff --git a/2510/CH10/EX10.1/Ex10_1.sce b/2510/CH10/EX10.1/Ex10_1.sce new file mode 100755 index 000000000..1360cb293 --- /dev/null +++ b/2510/CH10/EX10.1/Ex10_1.sce @@ -0,0 +1,13 @@ +//Variable declaration: +Gr = 100.0 //Grashof number +Re = 50.0 //Reynolds number + +//Calculation: +LT = Gr/Re**2 //Measure of influence of convection effect + +//Result: +if (LT<1.0) then + printf("The free convection effects can be neglected.") +elseif (LT>1.0) then + printf("The free convection effects can not be neglected.") +end diff --git a/2510/CH10/EX10.10/Ex10_10.sce b/2510/CH10/EX10.10/Ex10_10.sce new file mode 100755 index 000000000..554e71728 --- /dev/null +++ b/2510/CH10/EX10.10/Ex10_10.sce @@ -0,0 +1,13 @@ +//Variable declaration: +//From example 10.9: +h = 9.01 //Heat transferred from bulb (W/m^2.K) +D = 0.06 //Diameter of sphere (m) +Ts = 113.0+273.0 //Surface temperature of bulb (K) +Too = 31.0+273.0 //Ambient air temperature (K) + +//Calculation: +A = %pi*D**2 //Surface area of bulb (m^2) +Q = h*A*(Ts-Too) //Heat transfer lost by free convection from light bulb (W) + +//Result: +printf("The heat transfer lost by free convection from light bulb is : %.2f W .",Q) diff --git a/2510/CH10/EX10.11/Ex10_11.sce b/2510/CH10/EX10.11/Ex10_11.sce new file mode 100755 index 000000000..c8fd0df7e --- /dev/null +++ b/2510/CH10/EX10.11/Ex10_11.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 10.9-10.10: +Q = 8.36 //Heat transfer lost by free convection from light bulb (W) + +//Calculation: +E = Q/100.0*(100.0) //Percent energy lost by free convection (%) + +//Result: +printf("The percentage of the energy lost by free convection is : %.2f %%.",E) +printf("The energy lost fraction is : %.4f .",E/100.0) diff --git a/2510/CH10/EX10.13/Ex10_13.sce b/2510/CH10/EX10.13/Ex10_13.sce new file mode 100755 index 000000000..3211dbf9f --- /dev/null +++ b/2510/CH10/EX10.13/Ex10_13.sce @@ -0,0 +1,11 @@ +//Variable declaration: +F = 50.0 //Buoyancy flux of gas (m^4/s^3) +u = 4.0 //wind speed (m/s) + +//Calculation: +xc = 14*F**(5.0/8.0) //Downward distance (m) +xf = 3.5*xc //distance of transition from first stage of rise to the second stage of rise (m) +Dh = 1.6*F**(1.0/3.0)*u**-1*xf**(2.0/3.0) //Plume rise (m) + +//Result: +printf("The plume rise is : %.0f m .",Dh) diff --git a/2510/CH10/EX10.2/Ex10_2.sce b/2510/CH10/EX10.2/Ex10_2.sce new file mode 100755 index 000000000..942dbaf8c --- /dev/null +++ b/2510/CH10/EX10.2/Ex10_2.sce @@ -0,0 +1,20 @@ +//Variable declaration: +Ts = 110.0+273.0 //Surface temperature of plate (K) +Too = 30.0+273.0 //Ambient air temperature (K) +L = 3.5 //Height of plate (m) +g = 9.807 //Gravitational acceleration (m^2/s) + +//Calculation: +Tf = (Ts+Too)/2 //Film temperature (K) +DT = Ts - Too //Temperature difference between surface and air (K) +//From appendix: +v = 2.0*10**-5 //Kinematic viscosity for air (m^2/s) +k = 0.029 //Thermal conductivity for air (W/m.K) +Pr = 0.7 //Prandtl number +B = 1.0/Tf //Coefficient of expansion (K^-1) +Gr = g*B*DT*L**3/v**2 //Grashof number +Ra = Gr*Pr //Rayleigh number + +//Result: +printf("The Grashof number is : %.2f x 10^11 .",Gr/10**11) +printf("The Rayleigh number is : %.2f x 10^11 .",Ra/10**11) diff --git a/2510/CH10/EX10.3/Ex10_3.sce b/2510/CH10/EX10.3/Ex10_3.sce new file mode 100755 index 000000000..4e4c014c6 --- /dev/null +++ b/2510/CH10/EX10.3/Ex10_3.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 10.2: +Ra = 1.71*10**11 //Rayleigh number + +//Result: +if (Ra>10**9) then + printf("The convection flow category is turbulent.") +elseif(Ra<10**9) then + printf("The convection flow category is laminar.") +end diff --git a/2510/CH10/EX10.4/Ex10_4.sce b/2510/CH10/EX10.4/Ex10_4.sce new file mode 100755 index 000000000..5478014c7 --- /dev/null +++ b/2510/CH10/EX10.4/Ex10_4.sce @@ -0,0 +1,15 @@ +//Variable declaration: +//From Table 10.1: +c = 0.1 //Constant c +m = 1.0/3.0 //Constant for turbulent free conection +//From example 10.2: +Ra = 1.71*10**11 //Rayleigh number +k = 0.029 //Thermal conductivity (W/m.K) +L = 3.5 //Thickness of plate (m) + +//Calculation: +Nu = c*Ra**m //Average Nusselt number +h = Nu*k/L //Average heat transfer coefficient (W/m^2.K) + +//Result: +printf("The average heat transfer coefficient is : %.1f W/m^2.K .",h) diff --git a/2510/CH10/EX10.6/Ex10_6.sce b/2510/CH10/EX10.6/Ex10_6.sce new file mode 100755 index 000000000..85a5e7a26 --- /dev/null +++ b/2510/CH10/EX10.6/Ex10_6.sce @@ -0,0 +1,29 @@ +//Variable declaration: +Ts = 200.0+460.0 //Surface temperature of pipe (°R) +Too = 70.0+460.0 //Air temperature (°R) +D = 0.5 //Diameter of pipe (ft) +R = 0.73 //Universal gas constant (ft^3.atm.R^−1.lb.mol^−1) +P = 1.0 //Atmospheric pressure (Pa) +MW = 29.0 //Molecular weight of fluid (mol) +//From Appendix: +mu = 1.28*10**-5 //Absolute viscosity (lb/ft.s) +k = 0.016/3600.0 //Thermal conductivity (Btu/s.ft.°F) +g = 32.174 //Gravitational acceleration (ft/s^2) + +//Calculation: +Tav = (Ts+Too)/2 //Average temperature (°R) +v = R*Tav/P //kinematic viscosity (ft^3/lbmol) +p = MW/v //Air density (lb/ft^3) +B = 1.0/Tav //Coefficient of expansion (°R^-1) +DT = Ts-Too //Temperature difference (°R) +Gr = D**3*p**2*g*B*DT/mu**2 //Grashof number +//From equation 10.5: +Cp = 0.25 //Air heat capacity (Btu/lb.°F) +Pr = Cp*mu/k //Prandtl number +GrPr = 10**8.24 //Rayleigh number +//From Holman^(3): +Nu = 10**(1.5) //Nusselt number +h = Nu*(k/D)*3600.0 //Air heat transfer film coefficient (Btu/h.ft.°F) + +//Result: +printf("The required air heat transfer film coefficient is : %.2f Btu/h.ft.°F .",h) diff --git a/2510/CH10/EX10.7/Ex10_7.sce b/2510/CH10/EX10.7/Ex10_7.sce new file mode 100755 index 000000000..ba85adbcb --- /dev/null +++ b/2510/CH10/EX10.7/Ex10_7.sce @@ -0,0 +1,22 @@ +//Variable declaration: +Ts = 120.0+460 //Surface temperature of plate (°R) +Too = 60.0+460 //Ambient temperature of nitrogen (°R) +L = 6 //Height of plate (ft) +//From Appendix: +p = 0.0713 //Air density (lb/ft^3) +k = 0.01514 //Thermal conductivity (Btu/h.ft.°F) +v = 16.82*10**-5 //Kinematic viscosity (ft^2/s) +Pr = 0.713 //Prandtl number +g = 32.2 //Gravitational acceleration (ft/s^2) + +//Calculation: +Tf = (Ts+Too)/2 //Mean film temperature (°R) +B = 1.0/Tf //Coefficient of expansion (°R^-1) +Gr = g*B*(Ts-Too)*L**3/v**2 //Grashof number +Ra = Gr*Pr //Rayleigh number +//From equation 10.13(Table 10.2) and costants from Table 10.1: +h = 0.10*(k/L)*Ra**(1.0/3.0) //Free convection heat transfer coefficient (Btu/h.ft^2.°F) + +//Result: +printf("The free convection heat transfer coefficient is : %.3f Btu/h.ft^2.°F .",h) +printf("There is a calculation mistake in the book for calculating Gr, so, value of h alters from that given.") diff --git a/2510/CH10/EX10.8/Ex10_8.sce b/2510/CH10/EX10.8/Ex10_8.sce new file mode 100755 index 000000000..c90ec575a --- /dev/null +++ b/2510/CH10/EX10.8/Ex10_8.sce @@ -0,0 +1,14 @@ +//Variable declaration: +//From example: +h = 0.675 //Free convection heat transfer coefficient (Btu/h.ft^2.°F) +A = 6.0*8.0 //Area of plate (ft^2) +Ts = 120.0 //Surface temperature of plate (°F) +Too = 60.0 //Ambient temperature of nitrogen (°F) + +//Calculation: +Q = h*A*(Ts-Too) //Heat loss (Btu/h) +Q = round(Q * 10**-1)/10**-1 + +//Result: +printf("The heat loss is : %f Btu/h .",Q) +printf(" The h obtained in the previous example differs, therefore, Q obtained here also differs from that given in book.") diff --git a/2510/CH10/EX10.9/Ex10_9.sce b/2510/CH10/EX10.9/Ex10_9.sce new file mode 100755 index 000000000..97ce4585f --- /dev/null +++ b/2510/CH10/EX10.9/Ex10_9.sce @@ -0,0 +1,21 @@ +//Variable declaration: +Ts = 113.0+273.0 //Surface temperature of bulb (K) +Too = 31.0+273.0 //Ambient air temperature (K) +D = 0.06 //Diameter of sphere (m) +g = 9.8 //Gravitational acceleration (m/s^2) + +//Calculation: +Tf = (Ts+Too)/2 //Mean temperature (K) +//From Appendix: +v = (22.38*10**-5)*0.0929 //Kinematic viscosity (m^2/s) +Pr = 0.70 //Prandtl number +k = 0.01735*1.729 //Thermal conductivity (W/m.K) +B = 1.0/(Tf) //Coefficient of expansion (K^-1) +Gr = g*B*(Ts-Too)*D**3/v**2 //Grashof number +Ra = Gr*Pr //Rayleigh number + +//From equation 10.13: +h = (k/D)*0.6*Ra**(1.0/4.0) //Heat transferred from bulb (W/m^2.K) + +//Result: +printf("The heat transferred from bulb to air is : %.2f W/m^2.K.",h) diff --git a/2510/CH11/EX11.10/Ex11_10.sce b/2510/CH11/EX11.10/Ex11_10.sce new file mode 100755 index 000000000..234813c06 --- /dev/null +++ b/2510/CH11/EX11.10/Ex11_10.sce @@ -0,0 +1,12 @@ +//Variable declaration: +TH = 140.0+460.0 //Absolute outside temperature of pipe (ft^2) +TC = 60.0+460.0 //Absolute temperature of surrounding atmosphere (ft^2) +A = 10.0 //Area of pipe (ft^2) +E = 0.9 //Emissivity of pipe + +//Calculation: +Q = E*A*0.173*((TH/100.0)**4-(TC/100.0)**4) //Heat loss due to radiation (Btu/h) +Q = round(Q*10**-1)/10**-1 + +//Result: +printf("The heat loss due to radiation is : %f Btu/h.",Q) diff --git a/2510/CH11/EX11.11/Ex11_11.sce b/2510/CH11/EX11.11/Ex11_11.sce new file mode 100755 index 000000000..ded3aa878 --- /dev/null +++ b/2510/CH11/EX11.11/Ex11_11.sce @@ -0,0 +1,12 @@ +//Variable declaration: +//Froma example 11.10: +Q = 880.0 //Heat loss due to radiation (Btu/h) +A = 10.0 //Area of pipe (ft^2) +TH = 140.0 //Absolute outside temperature of pipe (°F) +TC = 60.0 //Absolute temperature of surrounding atmosphere (°F) + +//Calculation: +hr = Q/(A*(TH-TC)) //Radiation heat transfer coefficient (Btu/h.ft^2.°F) + +//Result: +printf("The radiation heat transfer coefficient is : %.1f Btu/h.ft^2.°F.",hr) diff --git a/2510/CH11/EX11.12/Ex11_12.sce b/2510/CH11/EX11.12/Ex11_12.sce new file mode 100755 index 000000000..d808e5af5 --- /dev/null +++ b/2510/CH11/EX11.12/Ex11_12.sce @@ -0,0 +1,35 @@ +//Variable declaration: +D = 0.0833 //Diameter of tube (ft) +L = 2.0 //Length of tube (ft) +h = 2.8 //Heat transfer coefficient (Btu/h.ft^2.°F) +Ta1 = 1500.0+460.0 //Temperature of hot air in furnace (°R) +Ta2 = 1350.0+460.0 //Temperature of hot air in the furnace brick walls (°R) +Tt = 600.0+460.0 //Surface temperature of tube (°R) +E = 0.6 //Surface emissivity of tube +s = 0.1713*10**-8 //Stefan-Boltzmann constant +pi = %pi + +//Calculation: +//Case 1: +A = pi*D*L //Area of tube (ft^2) +Qc = round(h*A*(Ta1-Tt)*10**-1)/10**-1 //Convection heat transfer from air to tube (Btu/h) +Qr = round(E*s*A*(Ta2**4-Tt**4)*10**-2)/10**-2 //Radiation feat transfer from wall to tube (Btu/h) +Q = Qr+Qc //Total heat transfer (Btu/h) +//Case 2: +Qp = Qr/Q*100 //Radiation percent +//Case 3: +hr = Qr/(A*(Ta2-Tt)) //Radiation heat transfer coefficient (Btu/h.ft^2.°F) +//Case 4: +T = Ta2-Tt //Temperature difference (°F) + +//Result: +printf("1. The convective heat transferred to the metal tube is : %f Btu/h.",Qc) +printf(" The radiative heat transferred to the metal tube is : %f Btu/h.",Qr) +printf(" The total heat transferred to the metal tube is : %f Btu/h .",Q) +printf("2. The percent of total heat transferred by radiation is : %.1f %%.",Qp) +printf("3. The radiation heat transfer coefficient is : %.1f Btu/h.ft^2.°F.",hr) +if (T > 200) then + printf("4. The use of the approximation Equation (11.30), hr = 4EsTav^3, is not appropriate.") +elseif (T < 200) then + printf("4. The use of the approximation Equation (11.30), hr = 4EsTav^3, is appropriate.") +end diff --git a/2510/CH11/EX11.13/Ex11_13.sce b/2510/CH11/EX11.13/Ex11_13.sce new file mode 100755 index 000000000..813920638 --- /dev/null +++ b/2510/CH11/EX11.13/Ex11_13.sce @@ -0,0 +1,12 @@ +//Variable declaration: +Q = 5.0 //Radiation heat transfer (W) +E = 1.0 //Emissivity of filament +s = 5.669*10**-8 //Stefan-Boltzmann constant +T1 = 900.0+273.0 //Light bulb temperature (K) +T2 = 150.0+273.0 //Glass bulb temperature (K) + +//Calculation: +A = Q/(E*s*(T1**4-T2**4)) //Surface area of the filament (m^2) + +//Result: +printf("The surface area of the filament is : %.2f cm^2",A*10**4) diff --git a/2510/CH11/EX11.14/Ex11_14.sce b/2510/CH11/EX11.14/Ex11_14.sce new file mode 100755 index 000000000..91ab7fd9a --- /dev/null +++ b/2510/CH11/EX11.14/Ex11_14.sce @@ -0,0 +1,25 @@ +//Variable declaration: +T1 = 127.0+273.0 //Surface temperature (K) +T2 = 20.0+273.0 //Wall temperature (K) +T3 = 22.0+273.0 //Air temperature (K) +s = 5.669*10**-8 //Stefan-Boltzmann constant +e = 0.76 //Surface emissivity of anodized aluminium +D = 0.06 //Diameter of %pipe (m) +L = 100.0 //Length of %pipe (m) +h = 15.0 //%pipe convective heat transfer coefficient (W/m^2.K) + +//Calculation: +Eb = s*T1**4 //Emissive energy of %pipe (W/m^2) +E = e*Eb //Emissive power from surface of %pipe (W/m^2) +A = %pi*D*L //Surface area of %pipe (m^2) +Qc = h*A*(T1-T3) //Convection heat transfer to air (W) +Qr = e*s*A*(T1**4-T2**4) //Radiation heat transfer rate (W) +Q = Qc+Qr //Total heat transfer rate (Btu/h) +Tav = (T1+T2)/2.0 //Average temperature (K) +hr = 4*e*s*Tav**3 //Radiation heat transfer coefficient (W/m^2.K) + +//Result: +printf("The emissive power from surface of %%pipe is : %.0f W/m^2.",E) +printf("The convection heat transfer to air is : %.1f kW.",Qc/10**3) +printf("The radiation heat transfer rate is : %.1f kW",Qr/10**3) +printf("The radiation heat transfer coefficient is : %.1f W/m^2.K.",hr) diff --git a/2510/CH11/EX11.15/Ex11_15.sce b/2510/CH11/EX11.15/Ex11_15.sce new file mode 100755 index 000000000..6d61ab3f2 --- /dev/null +++ b/2510/CH11/EX11.15/Ex11_15.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 11.14: +Qc = 15.0 //Convection heat transfer coefficient (W/m^2.K) +hr = 7.2 //Radiation heat transfer coefficient (W/m^2.K) + +//Calculation: +X = hr/(Qc+hr)*100.0 //Percent heat transfer by radiation (%) + +//Result: +printf("The percent heat transfer by radiation is : %.1f %%.",X) diff --git a/2510/CH11/EX11.16/Ex11_16.sce b/2510/CH11/EX11.16/Ex11_16.sce new file mode 100755 index 000000000..9b7dbbfec --- /dev/null +++ b/2510/CH11/EX11.16/Ex11_16.sce @@ -0,0 +1,15 @@ +//Variable declaration: +FV = 1.0 //Correction factor +//From example 11.9: +FE = 0.358 //Emissivity correction factor +TH = 300.0+460.0 //Absolute temperature of external surface (°R) +TC = 75.0+460.0 //Absolute temperature of duct (°R) +AH = 0.622 //Area of pipe (ft^2) +s = 0.173*10**-8 //Stefan-Boltzmann constant + +//Calculation: +Q = FV*FE*AH*s*(TH**4-TC**4) //Heat transfer rate (Btu/h.ft) + +//Result: +printf("The heat transfer rate is : %.2f Btu/h.ft",Q) +printf("Since, Q obtained in (11.9) is 96.96 Btu/h.ft, the solution does not match with book.") diff --git a/2510/CH11/EX11.17/Ex11_17.sce b/2510/CH11/EX11.17/Ex11_17.sce new file mode 100755 index 000000000..46e7f8b55 --- /dev/null +++ b/2510/CH11/EX11.17/Ex11_17.sce @@ -0,0 +1,24 @@ +//Variable declaration: +//From figure 11.2: +L = 1.0 //Space between plates (m) +X = 0.5 //Length of plate (m) +Y = 2.0 //Width of plate (m) +s = 5.669*10**-8 //Stefan-Boltzmann constant +TH = 2000.0+273.0 //Temperature of hotter plate (K) +TC = 1000.0+273.0 //Temperature of colder plate (K) +Btu = 0.2934*10**-3 //Btu/h in a KW + +//Calculation: +A = X*Y //Area of plate (m^2) +Z1 = Y/L //Ratio of width with space +Z2 = X/L //Ratio of length with space +//From figure 11.2: +FV = 0.18 //Correction factor +FE = 1.0 //Emissivity correction factor +Q1 = FV*FE*s*A*(TH**4-TC**4) //Net radiant heat exchange between plates (kW) +Q2 = Q1/Btu //Net radiant heat exchange between plates in Btu/h (Btu/h) +Q1 = round(Q1*10**-2)/10**-2 + +//Result: +printf("The net radiant heat exchange between plates is : %f kW.",Q1) +printf("The net radiant heat exchange between plates in Btu/h is : %.2f x 10^8 Btu/h.",Q2/10**8) diff --git a/2510/CH11/EX11.3/Ex11_3.sce b/2510/CH11/EX11.3/Ex11_3.sce new file mode 100755 index 000000000..0af8b179b --- /dev/null +++ b/2510/CH11/EX11.3/Ex11_3.sce @@ -0,0 +1,9 @@ +//Variable declaration: +syms l //Wavelength (mu.m) +I = 40*exp(-l**2) //Intensity of radiation (Btu/h.ft^2.mu.m) + +//Calculation: +E = eval(integrate(I, l,0,%inf)) //Total emissive power (Btu/h.ft^2) + +//Result: +printf("The total emissive power is : %.1f Btu/h.ft^2.",E) diff --git a/2510/CH11/EX11.4/Ex11_4.sce b/2510/CH11/EX11.4/Ex11_4.sce new file mode 100755 index 000000000..a31d594c6 --- /dev/null +++ b/2510/CH11/EX11.4/Ex11_4.sce @@ -0,0 +1,14 @@ +//Variable declaration: +l = 0.25 //Wavelength (mu.m) +//From equation 11.4: +lT = 2884 //Product of wavelength and absolute temperature (mu.m.°R) + +//Calculation: +T = lT/l //Sun's temperature (°R) +T1 = round(T * 10**-2)/10**-2 +T = T - 460 +T460 = round(T * 10**-3)/10**-3 + +//Result: +printf("The Sun s temperature is : %f °R.",T1) +printf("The Sun s temperature in fahrenheit scale is : %f °F.",T460) diff --git a/2510/CH11/EX11.5/Ex11_5.sce b/2510/CH11/EX11.5/Ex11_5.sce new file mode 100755 index 000000000..d2c3cfd5b --- /dev/null +++ b/2510/CH11/EX11.5/Ex11_5.sce @@ -0,0 +1,11 @@ +//Variable declaration: +T1 = 1500.0+460.0 //Absolute temperature 1 (°R) +T2 = 1000.0+460.0 //Absolute temperature 2 (°R) + +//Calculation: +X = T1**4/T2**4 //Ratio of quantity of heat transferred +x = 100*(T1**4-T2**4)/T2**4 //Percentage increase in heat transfer (%) + +//Result: +printf("The ratio of the quantity/rate of heat transferred is : %.2f .",X) +printf("The percentage increase in heat transfer is : %.0f %%",x) diff --git a/2510/CH11/EX11.6/Ex11_6.sce b/2510/CH11/EX11.6/Ex11_6.sce new file mode 100755 index 000000000..46239f3ac --- /dev/null +++ b/2510/CH11/EX11.6/Ex11_6.sce @@ -0,0 +1,10 @@ +//Variable declaration: +T1 = 1200.0+460.0 //Absolute temperature of wall 1 (°R) +T2 = 800.0+460.0 //Absolute temperature of wall 2 (°R) + +//Calculation: +//From equation 11.23: +X = 0.173*((T1/100.0)**4-(T2/100.0)**4) //Heat removed from colder wall (Btu/h.ft^2) + +//Result: +printf("The heat removed from the colder wall to maintain a steady-state is : %.0f Btu/h.ft^2.",X) diff --git a/2510/CH11/EX11.7/Ex11_7.sce b/2510/CH11/EX11.7/Ex11_7.sce new file mode 100755 index 000000000..afaca937d --- /dev/null +++ b/2510/CH11/EX11.7/Ex11_7.sce @@ -0,0 +1,13 @@ +//Variable declaration: +s = 0.173 //Stefan-Boltzmann constant (Btu/h.ft^2.°R) +EH = 0.5 //Energy transferred from hotter body (Btu/h.ft^2) +EC = 0.75 //Energy transferred to colder body (Btu/h.ft^2) +TH = 1660.0 //Absolute temperature of hotter body (°R) +TC = 1260.0 //Absolute temperature of colder body (°R) + +//Calculation: +E = s*((TH/100.0)**4-(TC/100.0)**4)/((1.0/EH)+(1.0/EC)-1.0) //Net energy exchange per unit area (Btu/h.ft^2) +E = round(E*10**-1)/10**-1 + +//Result: +printf("The net energy exchange per unit area is : %f Btu/h.ft^2.",E) diff --git a/2510/CH11/EX11.8/Ex11_8.sce b/2510/CH11/EX11.8/Ex11_8.sce new file mode 100755 index 000000000..936f56aaf --- /dev/null +++ b/2510/CH11/EX11.8/Ex11_8.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 11.6-11.7: +E1 = 8776.0 //Energy exchange between black bodies (Btu/h.ft^2) +E2 = 3760.0 //Energy exchange between non-black bodies (Btu/h.ft^2) + +//Calculation: +D = (E1-E2)/E1*100 //Percent difference in energy (%) + +//Result: +printf("The percent difference relative to the black body is: %.1f %%.",D) diff --git a/2510/CH11/EX11.9/Ex11_9.sce b/2510/CH11/EX11.9/Ex11_9.sce new file mode 100755 index 000000000..504fb2449 --- /dev/null +++ b/2510/CH11/EX11.9/Ex11_9.sce @@ -0,0 +1,18 @@ +//Variable declaration: +s = 0.173*10**-8 //Stefan-Boltzmann constant (Btu/h.ft^2.°R) +TH = 300.0+460.0 //Absolute temperature of external surface (°R) +TC = 75.0+460.0 //Absolute temperature of duct (°R) +//From Table 6.2: +AH = 0.622 //External surface area of pipe (ft^2) +//From Table 11.2: +EH = 0.44 //Emissivity of oxidized steel +AC = 4.0*1.0*1.0 //External surface area of duct (ft^2) +EC = 0.23 //Emissivity of galvanized zinc + +//Calculation: +FE = 1.0/(1.0/EH+((AH/AC)*(1.0/EC-1.0))) //Emissivity correction factor +Q = FE*AH*s*(TH**4-TC**4) //Net radiation heat transfer (Btu/h.ft) + +//Result: +printf("The net radiation heat transfer is : %.2f Btu/h.ft^2.",Q) +printf("There is a calculation error in book.") diff --git a/2510/CH12/EX12.10/Ex12_10.sce b/2510/CH12/EX12.10/Ex12_10.sce new file mode 100755 index 000000000..5de5b331b --- /dev/null +++ b/2510/CH12/EX12.10/Ex12_10.sce @@ -0,0 +1,16 @@ +//Variable declaration: +//From example 12.9: +Ts1 = 102.0 //Original surface temperature (°C) +Ts2 = 103.0 //New surface temperature (°C) +Tsat = 100.0 //Saturation temperature (°C) + +//Calculation: +DTe1 = (Ts1 - Tsat) //Original excess temperature (°C) +DTe2 = (Ts2 - Tsat) //New excess temperature (°C) + +//Result: +printf("The original excess temperature is: DTe = %f °C .",DTe1) +printf("The new excess temperature is: DTe = %f °C .",DTe2) +if ((DTe1 < 5) & (DTe2 < 5)) then + printf("The assumption of the free convection mechanism is valid since DTe < 5°C.") +end diff --git a/2510/CH12/EX12.11/Ex12_11.sce b/2510/CH12/EX12.11/Ex12_11.sce new file mode 100755 index 000000000..85c0af1ef --- /dev/null +++ b/2510/CH12/EX12.11/Ex12_11.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 12.9: +Cp = 4127.0 //heat capacity (J/kg . K) +DTe = 3.0 //New excess temperature (°C) +h_vap = 2.26*10**6 //latent heat of vaporization (J/kg) + +//Calculation: +Ja_L = Cp*DTe/h_vap //Liquid Jakob number + +//Result: +printf("The liquid Jakob number is : %.5f",Ja_L) diff --git a/2510/CH12/EX12.12/Ex12_12.sce b/2510/CH12/EX12.12/Ex12_12.sce new file mode 100755 index 000000000..d07af2ad0 --- /dev/null +++ b/2510/CH12/EX12.12/Ex12_12.sce @@ -0,0 +1,29 @@ +//Variable declaration: +Ts = 106.0 //Surface temperature (°C) +Tsat = 100.0 //Saturation temperature (°C) + +//Calculation: +DTe = Ts-Tsat //Excess temperature (°C) +//From table 12.5: +C1 = 5.56 //Constant C1 +n1 = 3.0 //Constant n1 +C2 = 1040.0 //Constant C2 +n2 = 1.0/3.0 //Constant n2 +P = 1.0 //Absolute pressure (atm) +Pa = 1.0 //Ambient absolute pressure (atm) + +//Calculation: +h1 = C1*DTe**n1*(P/Pa)**0.4 //Boiling water heat transfer coefficient (W/m^2) +Qs1 = h1*DTe //Surface flux (W/m^2) +h2 = C2*DTe**n2*(P/Pa)**0.4 //Second Boiling water heat transfer coefficient (W/m^2) +Qs2 = h2*DTe //Second Surface flux (W/m^2) + +//Result: + +if (Qs1/10**3 > 15.8 & Qs1/10**3 < 236) then + printf("The boiling regime is : %.1f kW/m^2 .",Qs1/10**3) + printf("The heat transfer coefficient is : %.0f W/m^2 .",h1) +elseif (Qs1/10**3 < 15.8) then + printf("The boiling regime is : %.2f kW/m^2 .",Qs2/10**3) + printf("The heat transfer coefficient is : %.0f W/m^2.",h2) +end diff --git a/2510/CH12/EX12.13/Ex12_13.sce b/2510/CH12/EX12.13/Ex12_13.sce new file mode 100755 index 000000000..393070ec9 --- /dev/null +++ b/2510/CH12/EX12.13/Ex12_13.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 12.12: +Qs1 = 11340.0 //Surface flux (W/m^2) +D = 0.3 //Diameter of electric heater (m) + +//Calculation: +A = %pi*(D/2.0)**2 //Surface area of heater (m^2) +Qs = Qs1*A //Heat transfer rate (W) + +//Result: +printf("The rate of heat transfer is : %.0f W.",Qs) diff --git a/2510/CH12/EX12.2/Ex12_2.sce b/2510/CH12/EX12.2/Ex12_2.sce new file mode 100755 index 000000000..ba8669f3b --- /dev/null +++ b/2510/CH12/EX12.2/Ex12_2.sce @@ -0,0 +1,9 @@ +//Variable declaration: +C = 1 //Number of constituents +P = 1 //Number of phases + +//Calculation: +F = C-P+2 //Number of degrees of freedom + +//Result: +printf("The number of degrees of freedom is : %.2f .",F) diff --git a/2510/CH12/EX12.4/Ex12_4.sce b/2510/CH12/EX12.4/Ex12_4.sce new file mode 100755 index 000000000..b30b7a3a8 --- /dev/null +++ b/2510/CH12/EX12.4/Ex12_4.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From steam tables: +U1 = 1237.1 //Internnal energy of gas (Btu/lb) +U2_g = 1112.2 //Internal energy of gas (Btu/lb) +U2_l = 343.15 //Internal energy of liquid (Btu/lb) + +//Calculation: +Q = 0.5*(U2_g+U2_l)-1*U1 //Heat removed (Btu/lb) + +//Result: +printf("Heat removed from the system during the process is : %.1f Btu/lb.",Q) diff --git a/2510/CH12/EX12.5/Ex12_5.sce b/2510/CH12/EX12.5/Ex12_5.sce new file mode 100755 index 000000000..b35245a04 --- /dev/null +++ b/2510/CH12/EX12.5/Ex12_5.sce @@ -0,0 +1,39 @@ +//Variable declaration: +T1 = 99.0 //Mean film temperature (°C) +T2 = 98.0 //Plate surface temperature (°C) +g = 9.807 //Gravitational acceleration (m/s^2) +//From Appendix: +T3 = 100.0 //Saturation temperatre (°C) +h_vap1 = 970.3 //Latent heat of steam in Btu/lb (Btu/lb) +h_vap2 = 2.255*10**6 //Latent heat of steam in J/kg (J/kg) +p_v = 0.577 //Density of steam (kg/m^3) +p_l = 960.0 //Density of liquid water condensate (kg/m^3) +mu_l = 2.82*10**-4 //Absolute viscosity of liquid water condensate (kg/m.s) +k = 0.68 //Thermal conductivity of water (W/m.K) +//From table 12.2 +Z = 0.4 //Height of rectangular plate (m) +Pw = 0.2 //Wetted perimeter of rectangular plate (m) +syms h //Average heat transfer coefficient (W/m^2.K) + +//Calculation: +A = Z*Pw //Heat transfer area of plate (m^2) +R = A/Pw //Ratio A/Pw (m) +v_l = mu_l/p_l //Kinematic viscosity of liquid water condensate (m^2/s) +Co1 = (h/k)*(v_l**2/g/(1-p_v/p_l))**(1/3) //Condensation number (in terms of the average heat transfer coefficient) +Re = 4*h*Z*(T3-T2)/(mu_l*h_vap2) //Reynolds number in terms of the average heat transfer coefficient +//From equation 12.14: +CO1 = 0.0077*Re**Z //Co in terms of Reynolds number for flow type 1 +x1 = solve(h,Co1-CO1) //Solving heat transfer coefficient (W/m^2.K) +h1 =x1(2); //Average heat transfer coefficient for flow type 1 (W/m^2.K) +Re1 = subst(h1,h,Re) //Reynolds number for flow type 1 +CO2 = 1.874*Re**(-1/3) //Co in terms of Reynolds number for flow tupe 2 +x2 = solve(Co1-CO2,h) //Solving average heat transfer coefficient for flow type 2 (W/m^2.K) +h2 = x2(1); //Average heat transfer coefficient for flow type 2 (W/m^2.K) +Re2 = subst(h2,h,Re) //Reynolds number for flow type 2 +h2 = round(h2*10**-1)/10**-1 + +//Result: +printf("The type of condensation flow type 2 is laminar.") +disp("And the condensation heat transfer coefficient is : ") +disp(h2) +disp("W/m^2.K.") diff --git a/2510/CH12/EX12.6/Ex12_6.sce b/2510/CH12/EX12.6/Ex12_6.sce new file mode 100755 index 000000000..333baca4f --- /dev/null +++ b/2510/CH12/EX12.6/Ex12_6.sce @@ -0,0 +1,19 @@ +//Variable declaration: +//From example 12.5: +Re = 73.9 //Reynolds number +mu_l = 2.82*10**-4 //Absolute viscosity of liquid water condensate (kg/m.s) +Pw = 0.2 //Wetted perimeter of rectangular plate (m) +h = 14700.0 //Heat transfer coefficient (W/m^2.K) +T_sat = 100.0 //Saturation temperature (°C) +Ts = 98.0 //Surface temperature (°C) +A = 0.2*0.4 //Heat transfer area of plate (m^2) + +//Calculation: +m1 = Re*mu_l/4.0 //Mass flow rate of condensate (kg/m.s) +m = Pw*m1 //Mass flow rate of condensate (kg/s) +Co = (3.038*10**-5)*h //Condensation number +Q = h*A*(T_sat-Ts) //Heat transfer rate (W) + +//Result: +printf("1. The mass flow rate of condensate is : %.4f kg/m.s.",m1) +printf("2. The heat transfer rate is : %.2f kW.",Q/10**3) diff --git a/2510/CH12/EX12.7/Ex12_7.sce b/2510/CH12/EX12.7/Ex12_7.sce new file mode 100755 index 000000000..90331fcc8 --- /dev/null +++ b/2510/CH12/EX12.7/Ex12_7.sce @@ -0,0 +1,18 @@ +//Variable declaration: +T_sat = 126.0 //Saturation temperature (°F) +T = 64.0 //Surface temperature of tube (°F) +g = 32.2 //Gravitational acceleration (ft^2/s) +D = 4.0/12.0 //Outside diameter of tube (ft) + +//Calculation: +Tf = (T_sat+T)/2.0 //Mean film temperature (°F) +//From approximate values of key properties: +h_vap = 1022.0 //Latent heat of steam (Btu/lb) +p_v = 0.00576 //Density of steam (lb/ft^3) +p_l = 62.03 //Density of liquid (lb/ft^3) +k_l = 0.364 //Thermal conductivity of liquid (Btu/h.ft.°F) +mu_l = 4.26*10**-4 //Absolute viscosity of liquid water condensate (lb/ft.s) +h = 0.725*((p_l*(p_l-p_v)*g*h_vap*k_l**3)/(mu_l*D*(T_sat-T)/3600.0))**(1.0/4.0) //Average heat transfer coefficient (Btu/h.ft^2.°F) + +//Result: +printf("The average heat transfer coefficient is : %.1f Btu/h.ft^2.°F.",h) diff --git a/2510/CH12/EX12.9/Ex12_9.sce b/2510/CH12/EX12.9/Ex12_9.sce new file mode 100755 index 000000000..0a6ab11ee --- /dev/null +++ b/2510/CH12/EX12.9/Ex12_9.sce @@ -0,0 +1,16 @@ +//Variable declaration: +Qs1 = 9800.0 //Heat flux (W/m^2) +Ts1 = 102.0 //Original surface temperature (°C) +Ts2 = 103.0 //New surface temperature (°C) +Tsat = 100.0 //Saturation temperature (°C) + +//Calculation: +h1 = Qs1/(Ts1-Tsat) //Original heat transfer coefficient (W/m^2.K) +DT1 = (Ts1 - Tsat) //Original excess temperature (°C) +DT2 = (Ts2 - Tsat) //New excess temperature (°C) +n = 0.25 //Value of n for laminar flow +h2 = h1*(DT2/DT1)**(n) //New heat transfer coefficient (W/m^2.K) +Qs2 = h2*(Ts2-Tsat) //New heat flux (W/m^2) + +//Result: +printf("The new heat flux is : %.0f W/m^2.K .",Qs2) diff --git a/2510/CH13/EX13.1/Ex13_1.sce b/2510/CH13/EX13.1/Ex13_1.sce new file mode 100755 index 000000000..879546da7 --- /dev/null +++ b/2510/CH13/EX13.1/Ex13_1.sce @@ -0,0 +1,16 @@ +//Variable declaration: +LR = 7.5/12.0 //Thickness of refractory (ft) +LI = 3.0/12.0 //Thickness of insulation (ft) +LS = 0.25/12.0 //Thickness of steel (ft) +kR = 0.75 //Thermal conductivity of refractory +kI = 0.08 //Thermal conductivity of insulation +kS = 26.0 //Thermal conductivity of steel +TR = 2000.0 //Average surface temperature of the inner face of the refractory (°F) +TS = 220.0 //Average surface temperature of the outer face of the steel (°F) + +//Calculation: +DT = TR-TS //Temperature difference (°F) +Q = DT/(LR/kR+LI/kI+LS/kS) //Heat loss (Btu/h.ft^2)(here representing Qdot/A) + +//Result: +printf("The heat loss is : %.0f Btu/h.ft^2 .",Q) diff --git a/2510/CH13/EX13.10/Ex13_10.sce b/2510/CH13/EX13.10/Ex13_10.sce new file mode 100755 index 000000000..00ec06062 --- /dev/null +++ b/2510/CH13/EX13.10/Ex13_10.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 13.9: +TS = -10.0+273.0 //Fluid’s saturation temperature expressed in Kelvin (K) +QC = 160.0 //Heat absorbed by the evaporator (kJ/kg) + +//Calcuation: +DS = QC/TS //Fluid’s change in entropy(kJ/kg.K) + +//Result: +printf("The fluids change in entropy across the evaporator is : %.2f kJ/kg.K.",DS) diff --git a/2510/CH13/EX13.11/Ex13_11.sce b/2510/CH13/EX13.11/Ex13_11.sce new file mode 100755 index 000000000..63b906462 --- /dev/null +++ b/2510/CH13/EX13.11/Ex13_11.sce @@ -0,0 +1,13 @@ +//Variable declaration: +//From figure 13.2: +h1 = 390.0 //Fluid enthalpy on entering the compressor (kJ/kg) +h2 = 430.0 //Fluid enthalpy on leaving the compressor (kJ/kg) +h3 = 230.0 //Fluid enthalpy on leaving the condenser (kJ/kg) + +//Calculation: +QH = h2 - h3 //Heat rejected from the condenser (kJ/kg) +W_in = h2 - h1 //Change in enthalpy across the compressor (kJ/kg) +QC = QH - W_in //Heat absorbed by the evaporator (kJ/kg) + +//Result: +printf("The heat absorbed by the evaporator of the refrigerator is : %.0f kJ/kg.",QC) diff --git a/2510/CH13/EX13.12/Ex13_12.sce b/2510/CH13/EX13.12/Ex13_12.sce new file mode 100755 index 000000000..412ce1ace --- /dev/null +++ b/2510/CH13/EX13.12/Ex13_12.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 13.11: +W_in = 40.0 //Change in enthalpy across the compressor (kJ/kg) +QC = 160.0 //Heat absorbed by the evaporator (kJ/kg) + +//Calculation: +COP = QC/W_in //Refrigerator’s C.O.P. + +//Result: +printf("the refrigerators C.O.P. is : %.0f .",COP) diff --git a/2510/CH13/EX13.13/Ex13_13.sce b/2510/CH13/EX13.13/Ex13_13.sce new file mode 100755 index 000000000..a99521db8 --- /dev/null +++ b/2510/CH13/EX13.13/Ex13_13.sce @@ -0,0 +1,12 @@ +//Variable declaration: +h1 = 548.0 //Steam enthalpy at the entry and exit to the boiler (kJ/kg) +h2 = 3989.0 //Steam enthalpy at the entry and exit to the turbine (kJ/kg) +h3 = 2491.0 //Steam enthalpy at the entry and exit to the pump (kJ/kg) +QH = 2043.0 //Heat rejected by the condenser (kJ/kg) + +//Calculation: +h4 = h3 - QH //Steam enthalpy at the entry and exit to the condenser (kJ/kg) +Qb = h2 - h1 //Enthalpy change across the boiler (kJ/kg) + +//Result: +printf("The enthalpy change across the boiler is : %.0f kJ/kg.",Qb) diff --git a/2510/CH13/EX13.14/Ex13_14.sce b/2510/CH13/EX13.14/Ex13_14.sce new file mode 100755 index 000000000..9c874a53c --- /dev/null +++ b/2510/CH13/EX13.14/Ex13_14.sce @@ -0,0 +1,16 @@ +//Variable declaration: +//From example 13.4: +h1 = 548.0 //Steam enthalpy at the entry and exit to the boiler (kJ/kg) +h2 = 3989.0 //Steam enthalpy at the entry and exit to the turbine (kJ/kg) +h3 = 2491.0 //Steam enthalpy at the entry and exit to the pump (kJ/kg) +h4 = 448.0 //Steam enthalpy at the entry and exit to the condenser (kJ/kg) +Qb = 3441.0 //Enthalpy change across the boiler (kJ/kg) + +//Calculation: +Wt = h2 - h3 //Work produced by the turbine (kJ/kg) +Wp = h1 - h4 //Work used by the pump (kJ/kg) +W_net = Wt - Wp //Net work by subtracting the pump work from the turbine work (kJ/kg) +n_th = W_net/Qb //Thermal efficiency + +//Result: +printf("The thermal efficiency is : %.1f %%.",n_th*100) diff --git a/2510/CH13/EX13.15/Ex13_15.sce b/2510/CH13/EX13.15/Ex13_15.sce new file mode 100755 index 000000000..173de515e --- /dev/null +++ b/2510/CH13/EX13.15/Ex13_15.sce @@ -0,0 +1,17 @@ +//Variable declaration: +//From table 13.4: +x3 = 0.9575 //Mass fraction vapour at point 3 +h3 = 2491.0 //Steam enthalpy at the entry and exit to the pump (kJ/kg) +s3 = 7.7630 //Entropy at the entry and exit to the pump (kJ/kg.K) +s4 = 1.4410 //Entropy at the entry and exit to the condenser (kJ/kg.K) +//From example13.14: +h4 = 448.0 //Steam enthalpy at the entry and exit to the condenser (kJ/kg) + +//Calculation: +Q_out = h3 - h4 //Heat rejected (kJ/kg) +DS = s3 - s4 //Process change in entropy (kJ/kg) +T3 = Q_out/DS //Temperature at point 3 (K) + +//Result: +printf("The temperature at point 3 is : %.0f K.",T3) +printf("Or, the temperature at point 3 is : %.0f °C.",T3-273) diff --git a/2510/CH13/EX13.2/Ex13_2.sce b/2510/CH13/EX13.2/Ex13_2.sce new file mode 100755 index 000000000..6f44f747d --- /dev/null +++ b/2510/CH13/EX13.2/Ex13_2.sce @@ -0,0 +1,11 @@ +//Variable declaration: +LR = 7.5/12.0 //Thickness of refractory (ft) +kR = 0.75 //Thermal conductivity of refractory +TR = 2000.0 //Average surface temperature of the inner face of the refractory (°F) +Q = 450.0 //Heat loss (Btu/h.ft^2) + +//Calculation: +TI = TR - Q*(LR/kR) //Temperature of the boundary where the refractory meets the insulation (°F) + +//Result: +printf("The temperature of the boundary where the refractory meets the insulation is : %.0f °F .",TI) diff --git a/2510/CH13/EX13.3/Ex13_3.sce b/2510/CH13/EX13.3/Ex13_3.sce new file mode 100755 index 000000000..2a4d3ac96 --- /dev/null +++ b/2510/CH13/EX13.3/Ex13_3.sce @@ -0,0 +1,9 @@ +//Variable declaration: +QbyA = 70000.0 //Total heat loss (Btu/h) +Q = 450.0 //Heat loss (Btu/h.ft^2) + +//Calculation: +A = QbyA/Q //Area available for heat transfer (ft^2) + +//Result: +printf("The area available for heat transfer is : %.1f ft^2 .",A) diff --git a/2510/CH13/EX13.9/Ex13_9.sce b/2510/CH13/EX13.9/Ex13_9.sce new file mode 100755 index 000000000..e055b2e30 --- /dev/null +++ b/2510/CH13/EX13.9/Ex13_9.sce @@ -0,0 +1,9 @@ +//Variable declaration: +h_out = 390.0 //Enthalpy of the fluid that exits from the evaporator (kJ/kg) +h_in = 230.0 //Enthalpy of the fluid that enters the unit (kJ/kg) + +//Calculation: +QC = h_out - h_in //Heat absorbed by the evaporator (kJ/kg) + +//Result: +printf("The heat absorbed by the evaporator is : %.0f kJ/kg.",QC) diff --git a/2510/CH14/EX14.1/Ex14_1.sce b/2510/CH14/EX14.1/Ex14_1.sce new file mode 100755 index 000000000..2f623ae7a --- /dev/null +++ b/2510/CH14/EX14.1/Ex14_1.sce @@ -0,0 +1,18 @@ +//Variable declaration: +scfm = 20000.0 //Volumetric flow rate of air at standard conditions (scfm) +H1 = 1170.0 //Enthalpy at 200°F (Btu/lbmol) +H2 = 14970.0 //Enthalpy at 2000°F (Btu/lbmol) +Cp = 7.53 //Average heat capacity (Btu/lbmol.°F) +T1 = 200.0 //Initial temperature (°F) +T2 = 2000.0 //Final temperature (°F) + +//Calculation: +n = scfm/359.0 //Flow rate of air in a molar flow rate (lbmol/min) +DH = H2 - H1 //Change in enthalpy (Btu/lbmol) +DT = T2 - T1 //Change in temperature (°F) +Q1 = n*DH //Heat transfer rate using enthalpy data (Btu/min) +Q2 = n*Cp*DT //Heat transfer rate using the average heat capacity data (Btu/min) + +//Result: +printf("The heat transfer rate using enthalpy data is : %.2f x 10^5 Btu/min.",Q1/10**5) +printf("The heat transfer rate using the average heat capacity data is : %.2f x 10^5 Btu/min.",Q2/10**5) diff --git a/2510/CH14/EX14.10/Ex14_10.sce b/2510/CH14/EX14.10/Ex14_10.sce new file mode 100755 index 000000000..33197c1ab --- /dev/null +++ b/2510/CH14/EX14.10/Ex14_10.sce @@ -0,0 +1,16 @@ +//Variable declaration: +A = 1.0 //Surface area of glass (m^2) +h1 = 11.0 //Heat transfer coefficient inside room (W/m^2.K) +L2 = 0.125*0.0254 //Thickness of glass (m) +k2 = 1.4 //Thermal conductivity of glass (W/m.K) +h3 = 9.0 //Heat transfer coefficient from window to surrounding cold air (W/m^2.K) + +//Calculation: +R1 = 1.0/(h1*A) //Internal convection resistance (K/W) +R2 = L2/(k2*A) //Conduction resistance through glass panel (K/W) +R3 = 1.0/(h3*A) //Outside convection resistance (K/W) +Rt = R1+R2+R3 //Total thermal resistance (K/W) +U = 1.0/(A*Rt) //Overall heat transfer coefficient (W/m^2.K) + +//Result: +printf("The overall heat transfer coefficient is : %.1f W/m^2.K.",U) diff --git a/2510/CH14/EX14.11/Ex14_11.sce b/2510/CH14/EX14.11/Ex14_11.sce new file mode 100755 index 000000000..67476a79d --- /dev/null +++ b/2510/CH14/EX14.11/Ex14_11.sce @@ -0,0 +1,11 @@ +//Variable declaration: +Dx = 0.049/12.0 //Thickness of copper plate (ft) +h1 = 208.0 //Film coefficient of surface one (Btu/h.ft^2.°F) +h2 = 10.8 //Film coefficient of surface two (Btu/h.ft^2.°F) +k = 220.0 //Thermal conductivity for copper (W/m.K) + +//Calculation: +U = 1.0/(1.0/h1+Dx/k+1.0/h2) //Overall heat transfer coefficient (Btu/h.ft^2.°F) + +//Result: +printf("The overall heat transfer coefficient is : %.2f Btu/h.ft^2.°F.",U) diff --git a/2510/CH14/EX14.12/Ex14_12.sce b/2510/CH14/EX14.12/Ex14_12.sce new file mode 100755 index 000000000..f43f5e73e --- /dev/null +++ b/2510/CH14/EX14.12/Ex14_12.sce @@ -0,0 +1,12 @@ +//Variable declaration: +Do = 0.06 //Outside diameter of pipe (m) +Di = 0.05 //Inside diameter of pipe (m) +ho = 8.25 //Outside coefficient (W/m^2.K) +hi = 2000.0 //Inside coefficient (W/m^2.K) +R = 1.33*10**-4 //Resistance for steel (m^2.K/W) + +//Calculation: +U = 1.0/(Do/(hi*Di)+R+1.0/ho) //Overall heat transfer coefficient (W/m^2.°K) + +//Result: +printf("The overall heat transfer coefficient is : %.2f W/m^2.°K.",U) diff --git a/2510/CH14/EX14.14/Ex14_14.sce b/2510/CH14/EX14.14/Ex14_14.sce new file mode 100755 index 000000000..c3cba5c92 --- /dev/null +++ b/2510/CH14/EX14.14/Ex14_14.sce @@ -0,0 +1,28 @@ +//Variable declaration: +Di = 0.825/12.0 //Pipe inside diameter (ft) +Do = 1.05/12.0 //Pipe outside diameter (ft) +Dl = 4.05/12.0 //Insulation thickness (ft) +l = 1.0 //Pipe length (ft) +kp = 26.0 //Thermal conductivity of pipe (Btu/h.ft.°F) +kl = 0.037 //Thermal conductivity of insulation (Btu/h.ft.°F) +hi = 800.0 //Steam film coefficient (Btu/h.ft^2.°F) +ho = 2.5 //Air film coefficient (Btu/h.ft^2.°F) +pi = %pi + +//Calculation: +ri = Di/2.0 //Pipe inside radius (ft) +ro = Do/2.0 //Pipe outside radius (ft) +rl = Dl/2.0 //Insulation radius (ft) +Ai = pi*Di*l //Inside area of pipe (ft^2) +Ao = pi*Do*l //Outside area of pipe (ft^2) +Al = pi*Dl*l //Insulation area of pipe (ft^2) +A_Plm = (Ao-Ai)/log(Ao/Ai) //Log mean area for steel pipe (ft^2) +A_Ilm = (Al-Ao)/log(Al/Ao) //Log mean area for insulation (ft^2) +Ri = 1.0/(hi*Ai) //Air resistance (m^2.K/W) +Ro = 1.0/(ho*Al) //Steam resistance (m^2.K/W) +Rp = (ro-ri)/(kp*A_Plm) //Pipe resistance (m^2.K/W) +Rl = (rl-ro)/(kl*A_Ilm) //Insulation resistance (m^2.K/W) +U = 1.0/(Ai*(Ri+Rp+Ro+Rl)) //Overall heat coefficient based on the inside area (Btu/h.ft^2.°F) + +//Result: +printf("The overall heat transfer coefficient based on the inside area of the pipe is : %.3f Btu/h.ft^2.°F .",U) diff --git a/2510/CH14/EX14.15/Ex14_15.sce b/2510/CH14/EX14.15/Ex14_15.sce new file mode 100755 index 000000000..a18cc385f --- /dev/null +++ b/2510/CH14/EX14.15/Ex14_15.sce @@ -0,0 +1,14 @@ +//Variable declaration: +//From example 14.14: +Di = 0.825/12.0 //%pipe inside diameter (ft) +L = 1.0 //%pipe length (ft) +Ui = 0.7492 //Overall heat coefficient (Btu/h.ft^2.°F) +Ts = 247.0 //Steam temperature (°F) +ta = 60.0 //Air temperature (°F) + +//Calculation: +Ai = %pi*Di*L //Inside area of %pipe (ft^2) +Q = Ui*Ai*(Ts-ta) //Heat transfer rate (Btu/h) + +//Result: +printf("The heat transfer rate is : %.1f Btu/h.",Q) diff --git a/2510/CH14/EX14.16/Ex14_16.sce b/2510/CH14/EX14.16/Ex14_16.sce new file mode 100755 index 000000000..f1cc5f60e --- /dev/null +++ b/2510/CH14/EX14.16/Ex14_16.sce @@ -0,0 +1,16 @@ + +//Variable declaration: +hw = 200.0 //Water heat coefficient (Btu/h.ft^2.°F) +ho = 50.0 //Oil heat coefficient (Btu/h.ft^2.°F) +hf = 1000.0 //Fouling heat coefficient (Btu/h.ft^2.°F) +DTlm = 90.0 //Log mean temperature difference (°F) +A = 15.0 //Area of wall (ft^2) + +//Calculation: +X = 1.0/hw+1.0/ho+1.0/hf //Equation 14.34 for constant A +U = 1.0/X //Overall heat coeffocient (Btu/h.ft^2.°F) +Q = U*A*DTlm //Heat transfer rate (Btu/h) +Q = round(Q*10**-1)/10**-1 + +//Result: +printf("The heat transfer rate is : %f Btu/h.",Q) diff --git a/2510/CH14/EX14.17/Ex14_17.sce b/2510/CH14/EX14.17/Ex14_17.sce new file mode 100755 index 000000000..e14d0f6d3 --- /dev/null +++ b/2510/CH14/EX14.17/Ex14_17.sce @@ -0,0 +1,35 @@ + //Variable declaration: +T = 80.0 //Pipe surface temperature (°F) +t1 = 10.0 //Brine inlet temperature (°F) +syms DT2 //Discharge temperature of the brine solution (°F) +m = 20*60 //Flowrate of brine solution (lb/h) +Cp = 0.99 //Heat capacity of brine solution (Btu/lb.°F) +U1 = 150 //Overall heat transfer coefficient at brine solution entrance (Btu/h.ft^2.°F) +U2 = 140 //Overall heat transfer coefficientat at brine solution exit (Btu/h.ft^2.°F) +A = 2.5 //Pipe surface area for heat transfer (ft^2) + +//Calculation: +DT1 = T-t1 //Temperature approach at the pipe entrance (°F) +Q = m*Cp*(DT1-DT2) //Energy balance to the brine solution across the full length of the pipe (Btu/h) +DT1m = (DT1-DT2)/log(DT1/DT2) //Equation for the LMTD +QQ = A*(U2*DT1-U1*DT2)/log(U2*DT1/U1/DT2) //Equation for the heat transfer rate (Btu/h) +E = QQ-Q //Energy balance equation +R = integrate(E,DT2,1.2) + // +DT = 51.6254331484575 //Log mean temperature difference +t2 = T-DT //In discharge temperature of the brine solution (°F) +t2c = 5/9*(t2-32) //In discharge temperature of the brine solution in °C (c/5 = (F-32)/9) +_Q_ = eval(subst(DT,DT2,Q)) //Heat transfer rate (Btu/h) + +Q1 = round(_Q_*10**-1)/10**-1 +Q2 = round(_Q_/3.412*10**-2)/10**-2 + +//Result: +printf("The temperature approach at the brine inlet side is : %.1f °F.",DT1) +printf("Or, the temperature approach at the brine inlet side is : %.1f °C.",DT1/1.8) +printf("The exit temperature of the brine solution is : %.2f °F.",t2) +printf("Or, the exit temperature of the brine solution is : %.1f °C.",(t2-32)/1.8) +printf("The rate of heat transfer is : %f Btu/h.",Q1) +printf("Or, the rate of heat transfer is : %f W.",Q2) + + diff --git a/2510/CH14/EX14.2/Ex14_2.sce b/2510/CH14/EX14.2/Ex14_2.sce new file mode 100755 index 000000000..632d51d66 --- /dev/null +++ b/2510/CH14/EX14.2/Ex14_2.sce @@ -0,0 +1,12 @@ +//Variable declaration: +n = 1200.0 //Flow rate of air in a molar flow rate (lbmol/min) +Cp = 0.26 //Average heat capacity (Btu/lbmol.°F) +T1 = 200.0 //Initial temperature (°F) +T2 = 1200.0 //Final temperature (°F) + +//Calculation: +DT = T2 - T1 //Change in temperature (°F) +Q = n*Cp*DT //Required heat rate (Btu/min) + +//Result: +printf("The required heat rate is : %.2f x 10^5 Btu/min.",Q/10**5) diff --git a/2510/CH14/EX14.3/Ex14_3.sce b/2510/CH14/EX14.3/Ex14_3.sce new file mode 100755 index 000000000..32770a949 --- /dev/null +++ b/2510/CH14/EX14.3/Ex14_3.sce @@ -0,0 +1,12 @@ +//Variable declaration: +Tc1 = 25.0 //Initial temperature of cold fluid (°C) +Th1 = 72.0 //Initial temperature of hot fluid (°C) +Th2 = 84.0 //Final temperature of hot fluid (°C) + +//Calculation: +//From equation 14.2: +Tc2 = (Th2-Th1)+Tc1 //Final temperature of cold fluid (°C) + +//Result: +printf("The final temperature of the cold liquid is : %f °C.",Tc2) +printf("There is a printing mistake in unit of final temperature in book.") diff --git a/2510/CH14/EX14.4/Ex14_4.sce b/2510/CH14/EX14.4/Ex14_4.sce new file mode 100755 index 000000000..22b0d7621 --- /dev/null +++ b/2510/CH14/EX14.4/Ex14_4.sce @@ -0,0 +1,9 @@ +//Variable declaration: +Ts = 100.0 //Steam temperature at 1 atm (°C) +Tl = 25.0 //Fluid temperature (°C) + +//Calculation: +DTlm = Ts - Tl //Log mean temperature difference (°C) + +//Result: +printf("The LMTD is : %f °C.",DTlm) diff --git a/2510/CH14/EX14.5/Ex14_5.sce b/2510/CH14/EX14.5/Ex14_5.sce new file mode 100755 index 000000000..897834383 --- /dev/null +++ b/2510/CH14/EX14.5/Ex14_5.sce @@ -0,0 +1,13 @@ +//Variable declaration: +Ts = 100.0 //Steam temperature at 1 atm (°C) +T1 = 25.0 //Initial fluid temperature (°C) +T2 = 80.0 //Final fluid temperature (°C) + +//Calculation: +DT1 = Ts - T1 //Temperature difference driving force at the fluid entrance (°C) +DT2 = Ts - T2 //Temperature driving force at the fluid exit (°C) +DTlm = (DT1 - DT2)/log(DT1/DT2) //Log mean temperature difference (°C) + +//Result: +printf("The LMTD is : %.1f °C.",DTlm) +printf("There is a calculation mistake regarding final result in book.") diff --git a/2510/CH14/EX14.6/Ex14_6.sce b/2510/CH14/EX14.6/Ex14_6.sce new file mode 100755 index 000000000..9bc785658 --- /dev/null +++ b/2510/CH14/EX14.6/Ex14_6.sce @@ -0,0 +1,13 @@ +//Variable declaration: +T1 = 500.0 //Temperature of hot fluid entering the heat exchanger (°F) +T2 = 400.0 //Temperature of hot fluid exiting the heat exchanger (°F) +t1 = 120.0 //Temperature of cold fluid entering the heat exchanger (°F) +t2 = 310.0 //Temperature of cold fluid exiting the heat exchanger (°F) + +//Calculation: +DT1 = T1 - t2 //Temperature difference driving force at the heat exchanger entrance (°F) +DT2 = T2 - t1 //Temperature difference driving force at the heat exchanger exit (°F) +DTlm = (DT1 - DT2)/(log(DT1/DT2)) //LMTD (driving force) for the heat exchanger (°F) + +//Result: +printf("The LMTD (driving force) for the heat exchanger is : %.0f °F.",DTlm) diff --git a/2510/CH14/EX14.7/Ex14_7.sce b/2510/CH14/EX14.7/Ex14_7.sce new file mode 100755 index 000000000..e78e683a8 --- /dev/null +++ b/2510/CH14/EX14.7/Ex14_7.sce @@ -0,0 +1,17 @@ +//Variable declaration: +m = 8000.0 //Rate of oil flow inside the tube (lb/h) +Cp = 0.55 //Heat capacity of oil (Btu/lb.°F) +T1 = 210.0 //Initial temperature of oil (°F) +T2 = 170.0 //Final temperature of oil (°F) +t = 60.0 //Tube surface temperature (°F) + +//Calculation: +DT = T2 - T1 //Change in temperature (°F) +Q = m*Cp*DT //Heat transferred from the heavy oil (Btu/h) +DT1 = T1 - t //Temperature difference driving force at the pipe entrance (°F) +DT2 = T2 - t //Temperature difference driving force at the pipe exit (°F) +DTlm = (DT1 - DT2)/(log(DT1/DT2)) //LMTD (driving force) for the heat exchanger (°F) + +//Result: +printf("The heat transfer rate is : %.0f Btu/h.",Q) +printf("The LMTD for the heat exchanger is : %.0f °F.",DTlm) diff --git a/2510/CH14/EX14.8/Ex14_8.sce b/2510/CH14/EX14.8/Ex14_8.sce new file mode 100755 index 000000000..fe3fcd8ab --- /dev/null +++ b/2510/CH14/EX14.8/Ex14_8.sce @@ -0,0 +1,19 @@ +//Variable declaration: +T1 = 138.0 //Temperature of oil entering the cooler (°F) +T2 = 103.0 //Temperature of oil leaving the cooler (°F) +t1 = 88.0 //Temperature of coolant entering the cooler (°F) +t2 = 98.0 //Temperature of coolant leaving the cooler (°F) + +//Calculation: +//For counter flow unit: +DT1 = T1 - t2 //Temperature difference driving force at the cooler entrance (°F) +DT2 = T2 - t1 //Temperature difference driving force at the cooler exit (°F) +DTlm1 = (DT1 - DT2)/(log(DT1/DT2)) //LMTD (driving force) for the heat exchanger (°F) +//For parallel flow unit: +DT3 = T1 - t1 //Temperature difference driving force at the cooler entrance (°F) +DT4 = T2 - t2 //Temperature difference driving force at the cooler exit (°F) +DTlm2 = (DT3 - DT4)/(log(DT3/DT4)) //LMTD (driving force) for the heat exchanger (°F) + +//Result: +printf("The LMTD for counter-current flow unit is : %.1f °F.",DTlm1) +printf("The LMTD for parallel flow unit is : %.1f °F.",DTlm2) diff --git a/2510/CH15/EX15.10/Ex15_10.sce b/2510/CH15/EX15.10/Ex15_10.sce new file mode 100755 index 000000000..744313fa8 --- /dev/null +++ b/2510/CH15/EX15.10/Ex15_10.sce @@ -0,0 +1,20 @@ +//Variable declaration: +MC = 2000.0 +mc = 1000.0 +U = 2000.0 +A = 10.0 +T1 = 300.0 +t1 = 60.0 +e = %e + +//Calculation: +B = 1.0/mc +b = 1.0/MC +x = B/b +y = U*(B-b) +T2 = ((x-y)*T1 + x*(e-y)*t1)/(2*e-1) +t2 = t1+(T1-T2)/x + +//Result: +printf("T2 = : %.0f ",T2) +printf("t2 = : %.0f ",t2) diff --git a/2510/CH15/EX15.11/Ex15_11.sce b/2510/CH15/EX15.11/Ex15_11.sce new file mode 100755 index 000000000..2b49cce78 --- /dev/null +++ b/2510/CH15/EX15.11/Ex15_11.sce @@ -0,0 +1,39 @@ + +//Variable declaration: +h1 = 1200.0 //Hot film coefficient (Btu/h.ft^2..) +h2 = 1175.0 //Cold film coefficient (Btu/h.ft^2..) +L = 200.0 //Length of pipe (ft) +MC = 30000.0 +mc = 22300.0 +T1 = 300.0 //Inlet temperature of hot fluid in pipe (.) +t1 = 60.0 //Inlet temperature of cold fluid in pipe (.) +syms T2 //Outlet temperature of hot fluid . +syms t2 //Outlet temperature of cold fluid . +//From table 6.2: +ID = 2.067 //Inside diameter of pipe (in) +OD = 2.375 //Outside diameter of pipe (in) +Dx = 0.154 //Thickness of pipe (in) +Ai = 0.541 //Inside sectional area of pipe (ft^2/ft) +k = 25.0 //Thermal conductivity of pipe (Btu/h) + +//Calculation: +Ui = 1.0/((1.0/h1) +(Dx/(k*12.0))+(1.0/(h2*(OD/ID)))) //Overall heat transfer coefficient (Btu/h.ft^2..) +Ai1 = Ai*L //Inside area of pipe (ft^3/ft) +QH = MC*(T1-T2) //Heat transfer rate of hot fluid (Btu/h) +QC = mc*(t2-t1) //Heat transfer rate of cold fluid (Btu/h) +t2ht = 195 //t2 by hit and trial +[x] = fsolve(T2,QC-QH) +T2 = x(1) +DTlm = (T1-t1-T2+t2)/log((T1-t1)/(T2-t2)) //Log mean temperature difference (.) +Q = Ui*Ai1*subst(t2ht,t2,DTlm) //Total heat transfer rate (Btu/h) + +//Result: +disp("T2 :") +disp(subst(t2ht,t2,T2)) + +disp("t2 :") +disp(subst(t2ht,t2,t2)) + +disp("Qdot :") +disp(Q/10**6) +disp("x 10**6 Btu/h") diff --git a/2510/CH15/EX15.12/Ex15_12.sce b/2510/CH15/EX15.12/Ex15_12.sce new file mode 100755 index 000000000..fc71588f8 --- /dev/null +++ b/2510/CH15/EX15.12/Ex15_12.sce @@ -0,0 +1,24 @@ + +//Variable declaration: +B = 3.33*10**-5 +b = 4.48*10**-5 +//From example 15.11: +A = 108.2 //Inside area of pipe (ft^3/ft) +U = 482 //Overall heat transfer coefficient (Btu/h.ft^2..) +MC = 30000.0 +mc = 23000.0 +T1 = 300.0 //Inlet temperature of hot fluid in pipe (.) +t1 = 60.0 //Inlet temperature of cold fluid in pipe (.) +e = %e + +//Calculation: +//From equation 15.28: +T2 = ((B/b)*(e**(U*A*(B-b))-1)*t1+T1*(B/b-1))/((B/b)*e**(U*A*(B-b))-1) //Outlet temperature of hot fluid (.) +//From equation 15.32: +t2 = ((b/B)*(e**(U*A*(b-B))-1)*T1+t1*(b/B-1))/((b/B)*e**(U*A*(b-B))-1) //Outlet temperature of cold fluid (.) +DT = ((T2-t1)-(T1-t2))/(log((T2-t1)/(T1-t2))) //Log mean difference temperature (.) +Q1 = U*A*DT //Heat transfer rate of hot fluid (Btu/h) +Q2 = MC*(T1-T2) //Heat transfer rate of cold fluid (Btu/h) +Q2 = round(Q2 * 10**-3)/10**-3 +//Result: +printf("The heat load is : %f Btu/h.",Q2) diff --git a/2510/CH15/EX15.14/Ex15_14.sce b/2510/CH15/EX15.14/Ex15_14.sce new file mode 100755 index 000000000..ac607cfe1 --- /dev/null +++ b/2510/CH15/EX15.14/Ex15_14.sce @@ -0,0 +1,33 @@ +//Variable declaration: +Ts = 100.0 //Saturation temperature (u00b0C) +t1 = 25.0 //Initial temperature of water (u00b0C) +t2 = 73.0 //Final temperature of water (u00b0C) +m = 228.0/3600.0 //Mass flow rate of water (kg/s) +cp = 4174.0 //Heat capacity of water (J/kg.K) +m_s = 55.0/3600.0 //Mass flow rate of steam (kg/s) +h_vap = 2.26*10**26 //Latent heat of condensation (J/kg) +k = 54.0 //Thermal conductivity for 0.5% carbon steel (W/m.K) +rii = 0.013 //Inner radius of inner %pipe of the double %pipe heat exchanger (m) +roi = 0.019 //Outer radius of inner %pipe of the double %pipe heat exchanger (m) +Rf = 0.0002 //Fouling factor (m^2.K/W) +Uc = 0.00045 //Clean overall heat transfer coefficient (W/m^2.K) + +//Calculation: +DT1 = Ts-t1 //Temperature driving force at end 1 (K) +DT2 = Ts-t2 //Temperature driving force at end 2 (K) +DTlm = (DT1-DT2)/(log(DT1/DT2)) //Log mean difference temperature (u00b0C) +Cw =m*cp //Capacitance rate of water (W/K) +Q = Cw*(t2-t1) //Heat transfer rate (W) +Qmax1 = Cw*(Ts-t1) //Maximum heat term from the water stream (W) +Qmax2 = m_s*h_vap //Maximum heat term from the steam (W) +E = Q/Qmax1 //Effectiveness +Lmin = (Q*(log(roi/rii)))/(2*%pi*k*(Ts-t1)) //Minimum required length of heat exchanger (m) +Ud = 1.0/(1.0/Uc+Rf) //Dirty overall heat transfer coefficient (W/m^2.K) +ud = round(1/Ud * 10**-1)/10**-1 + +//Result: +printf("1. The temperature profile of the water and steam along the length of the exchanger is : %.0f C .",DTlm) +printf("2. Effectiveness of energy from steam to heat the water is : %.3f .",E) +printf("3. The minimum length of the heat exchanger is : %.3f m .",Lmin) +printf("4. The dirty overall heat transfer coefficient : %.5f W/m^2.K",Ud) +printf("5. U_dirty: %f W/m^2.K",ud) diff --git a/2510/CH15/EX15.15/Ex15_15.sce b/2510/CH15/EX15.15/Ex15_15.sce new file mode 100755 index 000000000..d635dbd84 --- /dev/null +++ b/2510/CH15/EX15.15/Ex15_15.sce @@ -0,0 +1,12 @@ +//Variable declaration: +Q = 12700.0 //Heat transfer rate (W) +Ud = 2220.0 //Dirty overall heat transfer coefficient (W/m^2.K) +DTlm = 47.0 //Log mean difference temperature (u00b0C) +rii = 0.013 //Inner radius of inner %pipe of the double %pipe heat exchanger (m) +//Calculation: +A = Q/(Ud*DTlm) //Heat transfer area (m^2) +L = A/(2*%pi*rii) //Tube length (m) + +//Result: +printf("The heat transfer area is : %.4f m^2.",A) +printf("The length of the heat exchanger is : %.2f m.",L) diff --git a/2510/CH15/EX15.16/Ex15_16.sce b/2510/CH15/EX15.16/Ex15_16.sce new file mode 100755 index 000000000..b350a9c86 --- /dev/null +++ b/2510/CH15/EX15.16/Ex15_16.sce @@ -0,0 +1,10 @@ +//Variable declaration: +Ud = 2220.0 //Dirty overall heat transfer coefficient (W/m^2.K) +A = 0.1217 //Heat transfer area (m^2) +Cw = 264.0 //Capacitance rate of water (W/K) + +//Calculation: +NTU = (Ud*A)/Cw //Number of transfer units of the exchanger + +//Result: +printf("The number of transfer units (NTU) of the exchanger is : %.2f .",NTU) diff --git a/2510/CH15/EX15.18/Ex15_18.sce b/2510/CH15/EX15.18/Ex15_18.sce new file mode 100755 index 000000000..d0fb90e83 --- /dev/null +++ b/2510/CH15/EX15.18/Ex15_18.sce @@ -0,0 +1,10 @@ +//Variable declaration: +Ao = 1.85 //Area of heat exchanger (ft^2) + +//Calculation: +//From figure 15.6: +y = 0.560*10**-3 //Intercept 1/UoAo (..h/Btu) +ho = 1.0/(Ao*y) //Thermal conductivity for heat exchanger (Btu/h.ft^2..) + +//Result: +printf("Thermal conductivity for the heat exchanger is : %.0f Btu/h.ft^2.. .",ho) diff --git a/2510/CH15/EX15.19/Ex15_19.sce b/2510/CH15/EX15.19/Ex15_19.sce new file mode 100755 index 000000000..c66dbae43 --- /dev/null +++ b/2510/CH15/EX15.19/Ex15_19.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From figure 15.7: +a = 0.00126 +b = 0.0276 + +//Calculation: +ho = 1.0/a //The value of ho (Btu/h.ft^2..) + +//Result: +printf("Thermal conductivity is : %.0f Btu/h.ft^2.. .",ho) diff --git a/2510/CH15/EX15.2/Ex15_2.sce b/2510/CH15/EX15.2/Ex15_2.sce new file mode 100755 index 000000000..e44dc7bc7 --- /dev/null +++ b/2510/CH15/EX15.2/Ex15_2.sce @@ -0,0 +1,10 @@ +//Variable declaration: +Q = 12000.0 //Heat transfer rate (Btu/h) +U = 48.0 //Overall heat coefficient (Btu/ft^2.h..) +DTlm = 50.0 //Log mean temperature difference (.) + +//Calculation: +A = Q/(U*DTlm) //Area of exchanger (ft^2) + +//Result: +printf("The area of the exchanger is : %.0f ft^2 .",A) diff --git a/2510/CH15/EX15.20/Ex15_20.sce b/2510/CH15/EX15.20/Ex15_20.sce new file mode 100755 index 000000000..8f0f73974 --- /dev/null +++ b/2510/CH15/EX15.20/Ex15_20.sce @@ -0,0 +1,14 @@ +//Variable declaration: +Di = 0.902/12.0 //Inside diameter of tube (ft) +Do = 1.0/12.0 //Outside diameter of tube (ft) +k = 60.0 //Thermal conductivity of tube (Btu/h.ft^2..) + +//Calculation: +//From example 15.19: +a = 0.00126 +Dr = (Do - Di)/2.0 //Radial thickness of tube wall (ft) +Rw = Dr/k //Resistance of wall (Btu/h..) +ho = 1.0/(a-Rw) //The revised ho (Btu/h.ft^2..) + +//Result: +printf("The revised ho is : %.0f Btu/h.ft^2.. .",ho) diff --git a/2510/CH15/EX15.21/Ex15_21.sce b/2510/CH15/EX15.21/Ex15_21.sce new file mode 100755 index 000000000..817c8e347 --- /dev/null +++ b/2510/CH15/EX15.21/Ex15_21.sce @@ -0,0 +1,10 @@ +//Variable declaration: +a1 = 0.00044 //Term 'a' for U_clean +a2 = 0.00089 //Term 'a' for U_dirty + +//Calculation: +Rs = a2 - a1 //Resistance associated with the scale +hs = 1.0/Rs //Scale film coefficient (Btu/h.ft^2..) + +//Result: +printf("The scale film coefficient neglecting the wall resistance is: %.0f Btu/h.ft^2.. .",hs) diff --git a/2510/CH15/EX15.3/Ex15_3.sce b/2510/CH15/EX15.3/Ex15_3.sce new file mode 100755 index 000000000..e529b2f38 --- /dev/null +++ b/2510/CH15/EX15.3/Ex15_3.sce @@ -0,0 +1,21 @@ +//Variable declaration: +Q = 56760 //Heat transfer rate (Btu/h) +U = 35.35 //Overall heat coefficient (Btu/ft.h..) +A = 32.1 //Area of exachanger (ft^2) +t1 = 63.0 //Outlet cold water temperature (.) +T1 = 164 //Outlet hot water temperature (.) +T2 = 99 //Inlet hot water temperature (.) +syms t2 //Inlet cold water temperature (.) + +//Calculation: +DTlm = Q/(U*A) //Log mean temperature difference (.) +dT1 = T1-t1 //Temperature approach at pipe outlet (.) +dT2 = T2-t2 //Temperature approach at pipe inlet (.) +Eq = (dT2-dT1)/log(dT2/dT1)-DTlm +R = eval(subst(0,t2,Eq)) //Inlet cold water temperature (.) + +//Result: +disp("The inlet cold water temperature is : ") +disp(round(R)) + +// There is some mistake in calculation in book. Please calculate manually. diff --git a/2510/CH15/EX15.4/Ex15_4.sce b/2510/CH15/EX15.4/Ex15_4.sce new file mode 100755 index 000000000..9b2c2d187 --- /dev/null +++ b/2510/CH15/EX15.4/Ex15_4.sce @@ -0,0 +1,19 @@ +//Variable declaration: +m = 14.6 //Flow rate of water inside the tube (lb/min) +Cp = 1 //Heat capacity of water (Btu/lb..) +t2 = 79 //Initial temperature of water (.) +t1 = 63 //Final temperature of water (.) +//From example 15.3: +Q1 = 56760 //Old heat transfer rate (Btu/h) + +//Calculation: +Q2 = m*Cp*(t2-t1) //New heat transfer rate (Btu/min) + +//Result: +printf("The new heat transfer rate is : %.0f Btu/min.",Q2) +printf("Or, the new heat transfer rate is : %.0f Btu/h.",Q2*60) +if (Q1==Q2) then + printf("This result agree with the Qu02d9 provided in the problem statement. Shakespeare is wrong, nothing is rotten there.") +else + printf("This result does not agree with the Qu02d9 provided in the problem statement. Shakespeare is right, something is indeed rotten.") +end diff --git a/2510/CH15/EX15.5/Ex15_5.sce b/2510/CH15/EX15.5/Ex15_5.sce new file mode 100755 index 000000000..c92af9937 --- /dev/null +++ b/2510/CH15/EX15.5/Ex15_5.sce @@ -0,0 +1,17 @@ +//Variable declaration: +T1 = 210.0 //Initial temperature of oil (.) +T2 = 170.0 //Final temperature of oil (.) +T3 = 60.0 //Surface temperature of oil (.) +m = 8000.0 //Flow rate of oil inside tube (lb/h) +cp = 0.55 //Heat capacity of oil (Btu/lb..) +U = 63.0 //Overall heat teansfer coefficient (Btu.h.ft^2..) + +//Calculation: +DT1 = T1-T3 //Temperature difference 1 (.) +DT2 = T2-T3 //Temperature difference 2 (.) +DTlm = (DT1-DT2)/log(DT1/DT2) //Log mean temerature difference (.) +Q = m*cp*(T1-T2) //Heat transferred (Btu/h) +A = Q/(U*DTlm) //Heat transfer area (ft^2) + +//Result: +printf("The required heat transfer area is : %.2f ft^2 .",A) diff --git a/2510/CH15/EX15.6/Ex15_6.sce b/2510/CH15/EX15.6/Ex15_6.sce new file mode 100755 index 000000000..07d4c5ca8 --- /dev/null +++ b/2510/CH15/EX15.6/Ex15_6.sce @@ -0,0 +1,21 @@ +//Variable declaration: +T1 = 140.0 //Initial temperature of hot water (.) +T2 = 110.0 //Final temperature of hot water (.) +T3 = 60.0 //Initial temperature of cold water (.) +T4 = 90.0 //Initial temperature of cold water (.) +DTlm2 = 50.0 //Log mean temerature difference for countercurrent flow, a constant (.) (part 2) +m = 100.0*60 //Water flow rate (lb/h) +cp = 1.0 ////Heat capacity of water (Btu/lb..) +U = 750.0 //Overall heat teansfer coefficient (Btu.h.ft^2..) + +//Calculation: +DT1 = T1-T3 //Temperature difference 1 (.) (part 1) +DT2 = T2-T4 //Temperature difference 2 (.) +DTlm1 = (DT1-DT2)/log(DT1/DT2) //Log mean temerature difference (.) +Q = m*cp*(T1-T2) //Heat transferred (Btu/h) +Ap = Q/(U*DTlm1) //Heat transfer area for parallel flow (ft^2) +Ac = Q/(U*DTlm2) //Heat transfer area for counter flow (ft^2) + +//Result: +printf("1. The double pipe co-current flow is : %.2f ft^2 .",Ap) +printf("1. The double pipe countercurrent flow is : %.2f ft^2 .",Ac) diff --git a/2510/CH15/EX15.8/Ex15_8.sce b/2510/CH15/EX15.8/Ex15_8.sce new file mode 100755 index 000000000..d9c07b2a4 --- /dev/null +++ b/2510/CH15/EX15.8/Ex15_8.sce @@ -0,0 +1,61 @@ +//Variable declaration: +uC = 3.7*10**-4 //Viscosity of benzene (lb/ft.s) +uH = 2.05*10**-4 //Viscosity of water @200 . (lb/ft.s) +u2 = 2.16*10**-4 //Viscosity of water @192 . (lb/ft.s) +pC = 54.8 //Density of benzene (lb/ft^3) +pH = 60.13 //Density of water (lb/ft^3) +cpC = 0.415 //Specific heat capacity of benzene (Btu/lb..) +cpH = 1 //Specific heat capacity of water (Btu/lb..) +sgC = 0.879 +kC = 0.092 //Thermal conductivity of benzene (Btu/h.ft..) +kH = 0.392 //Thermal conductivity of water @200 . (Btu/h.ft..) +k2 = 0.390 //Thermal conductivity of water @192 . (Btu/h.ft..) +mC = 2500 //Flow rate of benzene (lb/s) +mH = 4000 //Flow rate of water (lb/s) +Re = 13000 //Reynolds number +dTc = 120-60 //Difference in temperature heating for benzene +Tw = 200 //Temperatperature of hot water (.) +//For 2-inch schedule 40 pipe +Ai = 0.541 //Inside area of pipe (ft^2/ft) +Ao = 0.622 //Outside area of pipe (ft^2/ft) +Di = 2.067 //Inside diameter of pipe (inch) +Do = 2.375 //Outside diameter of pipe (inch) +Si = 0.0233 //Inside surface area of pipe (ft^2) +dXw = 0.128 //Width of pipe (ft) +pi = %pi + +//For 4-inch schedule 40 pipe +Dio = 4.026 //Inside diameter of pipe (inch) +Doi = Do //Outside diameter of pipe (inch) +kw = 26 + +//Calculations: +function [a] = St(Re,Pr) //Dittus Boelter equation + a = 0.023*Re**-0.2*Pr**-0.667 +endfunction + +//For inside tubes: +Dicalc = 4*mC/(Re*pi*uC)/3600 //Inside diameter (ft) +mHcalc = Re*pi*uH*(Doi+Dio)/4*3600/12 //Mass flow rate of water (lb/h) +Q = mC*cpC*dTc //Heat in water (Btu/h) +dTH = Q/mH //Temperature difference of water (.) +THo = Tw - dTH //Outlet temperature of water (.) +THav = (Tw+THo)/2 //Average temperature of water (.) +//For benzene: +PrC = cpC*uC/kC*3600 //Prandtl number +StC = round(St(13000, PrC) * 10**5)/10**5 //Stanton number +hi = StC*cpC*mC/Si //Heat transfer coefficient (Btu/h.ft^2..) +//For water: +ReH = 4*mH/3600/(pi*u2*(Doi+Dio)/12) //Reynolds number +PrH = cpH*(u2)/k2*3600 //Prandtl number +StH = round(St(ReH, PrH) * 10**5)/10**5 //Stanton number +Sann = pi/4*(Dio**2-Doi**2)/144 //Surface area of annulus (ft^2) +ho = round(StH*cpH*mH/Sann) //Heat transfer coefficient (Btu/h.ft^2..) +//For pipe: +Dlm = (Do-Di)/log(Do/Di)*12 //Log mean difference in diameter (ft) +Uo = 1/(Do/Di/hi + dXw*Do/kw/Dlm + 1/ho) //Overall heat transfer coefficient (Btu/h.ft^2..) +dTlm = (124.4-80)/log(124.4/80) //Log mean temperature difference (.) +L = Q/(Uo*0.622*dTlm) //Length of pipe (ft) + +//Result: +printf("The required length of pipe: %.1f ft",L) diff --git a/2510/CH16/EX16.10/Ex16_10.sce b/2510/CH16/EX16.10/Ex16_10.sce new file mode 100755 index 000000000..c338ed1f9 --- /dev/null +++ b/2510/CH16/EX16.10/Ex16_10.sce @@ -0,0 +1,30 @@ +//Variable declaration: +t2 = 84.0 //Temperature of water leaving the tube ( C) +t1 = 16.0 //Temperature of water entering the tube ( C) +m1 = 10000.0/3600.0 //Mass flowrate of water (kg/s) +T2 = 94.0 //Temperature of oil leaving the shell ( C) +T1 = 160.0 //Temperature of oil entering the shell ( C) + +//Calculation: +Tw = (t1+t2)/2.0 //Average bulk temperature of water ( C) +To = (T1+T2)/2.0 //Average bulk temperature of oil ( C) +//From table 16.1: +p1 = 987.0 //Density of water (kg/m^3) +cp1 = 4176.0 //Heat capacity of water (J/kg. C) +p2 = 822.0 //Density of oil (kg/m^3) +Q = m1*cp1*(t2-t1) //Heat load (W) +cp2 = 4820.0 //Heat capacity of oil (J/kg. C) +m2 = Q/(cp2*(T1-T2)) //Mass flowrate of oil (kg/s) +DT1 = T2-t1 //Temperature driving force 1 ( C) +DT2 = T1-t2 //Temperature driving force 2 ( C) +DTlm1 = ((DT1-DT2)/log(DT1/DT2)) //Log mean temperature driving force for ideal countercurrent heat exchanger ( C) +P = (t2-t1)/(T1 - t1) //Dimensionless ratio P +R = (T1-T2)/(t2-t1) //Dimensionless ratio R +//From figure 16.7: +F = 0.965 //Correction factor +DTlm2 = F*DTlm1 //Log mean temperature driving force for 1-4 shell and tube exchanger ( C) + +//Result: +printf("1. The heat load is : %.3f MW .",Q/10**6) +printf("2. The countercurrent flow log mean temperature difference is : %.0f C .",DTlm1) +printf("3. The F correction factor and the corrected log mean temperature difference is : %.1f C .",DTlm2) diff --git a/2510/CH16/EX16.11/Ex16_11.sce b/2510/CH16/EX16.11/Ex16_11.sce new file mode 100755 index 000000000..d1cb37f7d --- /dev/null +++ b/2510/CH16/EX16.11/Ex16_11.sce @@ -0,0 +1,18 @@ +//Variable declaration: +//From example 16.10: +U = 350.0 //Over all heat transfer coefficient (W/m^2. C) +DTlm = 74.3 //Log mean temperature driving force for 1-4 shell and tube exchanger ( C) +Q = 788800.0 //Heat load (W) +Nt = 11.0 //Number of tubes per pass +Np = 4.0 //Number of passes +Di = 0.0229 //Inside diameter of tube (m) +pi = %pi + +//Calculation: +A = Q/(U*DTlm) //Heat transfer area required for heat exchanger (m^2) +N = Nt*Np //Total number of tubes +L = A/(pi*Di*N) //Tube length (m) + +//Result: +printf("The heat transfer area required for the heat exchanger is : %.2f m^2 .",A) +printf("The length of the tubes required for the heat exchanger is : %.1f ft",L*3.28) diff --git a/2510/CH16/EX16.18/Ex16_18.sce b/2510/CH16/EX16.18/Ex16_18.sce new file mode 100755 index 000000000..8dc81d9ca --- /dev/null +++ b/2510/CH16/EX16.18/Ex16_18.sce @@ -0,0 +1,33 @@ +//Variable declaration: +//From example 16.10: +m1 = 2.778 //Mass flowrate of water (kg/s) +cp1 = 4176.0 //Heat capacity of water (J/kg. C) +cp2 = 4820.0 //Heat capacity of oil (J/kg. C) +m2 = 2.48 //Mass flowrate of oil (kg/s) +t2 = 84.0 //Temperature of water leaving the tube ( C) +t1 = 16.0 //Temperature of water entering the tube ( C) +T2 = 94.0 //Temperature of oil leaving the shell ( C) +T1 = 160.0 //Temperature of oil entering the shell ( C) +U = 350.0 //Over all heat transfer coefficient (W/m^2. C) +A = 30.33 //Heat transfer area required for heat exchanger (m^2) + +//Calculation: +C1 = m1*cp1 //Capacitance rate of water (W/ C) +C2 = m2*cp2 //Capacitance rate of oil (W/ C) +Q = C1*(t2-t1) //Heat load of water (W) +Qmax = C1*(T1-t1) //Maximum heat load of water (W) +E = Q/Qmax //Effectiveness +if (C1<C2) then + Cmin = C1 //Minimum capacitance rate (W/ C) + Cmax = C2 //Maximum capacitance rate (W/ C) +else + Cmin = C2 //Minimum capacitance rate (W/ C) + Cmax = C1 //Maximum capacitance rate (W/ C) +end +NTU = U*A/Cmin //Number of transfer units +C = Cmin/Cmax //Capacitance rate ratio + +//Result: +printf("The effectiveness is : %.3f .",E) +printf("The number of transfer units is : %.3f",NTU) +printf("The capacitance rate ratio is : %.3f",C) diff --git a/2510/CH16/EX16.19/Ex16_19.sce b/2510/CH16/EX16.19/Ex16_19.sce new file mode 100755 index 000000000..a25a22911 --- /dev/null +++ b/2510/CH16/EX16.19/Ex16_19.sce @@ -0,0 +1,27 @@ +//Variable declaration: +//From table 16.4: +Cw = 11680.3 //Capacitance rate of water (W/ C) +t2 = 65.0 //Temperature of water leaving the tube ( C) +t1 = 20.0 //Temperature of water entering the tube ( C) +T2 = 107.3 //Temperature of steam leaving the shell ( C) +T1 = 107.3 //Temperature of steam entering the shell ( C) +hv = 2.238*10**6 //Latenet heat of condensation for steam (J/kg) +U = 2000.0 //Overall heat transfer coefficient (W/m^2. C) + +//Calculation: +Q = Cw*(t2-t1) //Heat load (W) +m2 = Q/hv //Steam condensation rate (kg/s) +DT1 = T2-t1 //Temperature driving force 1 ( C) +DT2 = T1-t2 //Temperature driving force 2 ( C) +DTlm1 = ((DT1-DT2)/log(DT1/DT2)) //Log mean temperature driving force for ideal countercurrent heat exchanger ( C) +F = 1.0 //Correction factor (since, T2 = T1) +DTlm2 = F*DTlm1 //Log mean temperature driving force for shell and tube exchanger ( C) +A1 = Q/(U*DTlm2) //Heat transfer area using LMTD method (m^2) +E = (t2-t1)/(T1-t1) //Effectiveness +//From figure 16.18: +NTU = 0.7 //Number of transfer units +A2 = (NTU*Cw)/U //Heat transfer area using E-NTU method (m^2) + +//Result: +printf("The heat transfr area for the exchanger (using LMTD method) is : %.2f m^2 .",A1) +printf("The heat transfr area for the exchanger (using E-NTU method) is : %.1f m^2",A2) diff --git a/2510/CH16/EX16.21/Ex16_21.sce b/2510/CH16/EX16.21/Ex16_21.sce new file mode 100755 index 000000000..5b5e22465 --- /dev/null +++ b/2510/CH16/EX16.21/Ex16_21.sce @@ -0,0 +1,51 @@ +//Variable declaration: +//From table 16.5: +t2 = 75.0 //Temperature of water leaving the shell ( C) +t1 = 35.0 //Temperature of water entering the shell ( C +T2 = 75.0 //Temperature of oil leaving the tube ( C) +T1 = 110.0 //Temperature of oil entering the tube ( C) +mw = 1.133 //Mass flowrtae of water (kg/s) +cpw = 4180.0 //Heat capacity of water (J/kg.K) +cpo = 1900.0 //Heat capacity of oil (J/kg.K) +p = 850.0 //Density of oil (kg/m^3) +Di = 0.01905 //Inside diameter of tube (m) +V = 0.3 //Average velocity of oil flow inside the tube (m/s) +Np = 2.0 //Number of passes +Uc = 350.0 //Overall heat transfer coefficient for clean heat exchanger (W/m^2) +Rf = 0.00027 //Fouling factor (m^2.K/w) +pi = %pi + +//Calculation: +Cw = mw*cpw //Water capacitance rate (W/K) +Q = Cw*(t2-t1) //Heat load (W) +Co = Q/(T1-T2) //Oil capacitance rate (W/K) +mo = Co/cpo //Total flowrate of oil (kg/s) +if (Cw<Co) then + Cmin = Cw //Minimum capacitance rate (W/K) + Cmax = Co //Maximum capacitance rate (W/K) +else + Cmin = Co //Minimum capacitance rate (W/K) + Cmax = Cw //Maximum capacitance rate (W/K) +end +m_ot = p*V*(pi/4.0)*Di**2 //Oil flowrate per tube (kg/s) +Nt = mo/m_ot //Number of tubes per pass +N = Nt*Np //Number of tubes +DT1 = T2-t1 //Temperature driving force 1 ( C) +DT2 = T1-t2 //Temperature driving force 2 ( C) +DTlm1 = ((DT1-DT2)/log(DT1/DT2)) //Log mean temperature driving force for ideal countercurrent heat exchanger ( C) +P = (t2-t1)/(T1 - t1) //Dimensionless parameter P +R = (T1-T2)/(t2-t1) //Dimensionless parameter R +//From figure 16.7: +F = 0.81 //Correction factor +DTlm2 = F*DTlm1 //Log mean temperature driving force for shell and tube exchanger ( C) +Ud = 1.0/(1.0/Uc+Rf) //Dirty overall heat transfer coefficient (W/m^2.K) +A = Q/(Ud*DTlm2) //Required heat transfer area (m^2) +L = A/(N*pi*Di) //Tube length (m) +N = round(N*10**-1)/10**-1 + +//Result: +printf("1. The mass flow rate of the oil is : %.2f kg/s .",mo) +printf("2. The minimum and maximum heat capacity rate is : %.0f and %.1f W/K",Cmin,Cmax) +printf("3. The heat load, Q is : %.0f W .",Q) +printf("4. The total number of tubes is : %f ",N) +printf("5. The tube length is : %.1f m .",L) diff --git a/2510/CH16/EX16.22/Ex16_22.sce b/2510/CH16/EX16.22/Ex16_22.sce new file mode 100755 index 000000000..5c289d40d --- /dev/null +++ b/2510/CH16/EX16.22/Ex16_22.sce @@ -0,0 +1,19 @@ +//Variable declaration: +//From example 16.22: +t2 = 75.0 //Temperature of water leaving the shell ( F) +t1 = 35.0 //Temperature of water entering the shell ( F) +T2 = 75.0 //Temperature of oil leaving the tube ( F) +T1 = 110.0 //Temperature of oil entering the tube ( F) +U = 320.0 //Overall heat transfer coefficient (W/m^2.K) +A = 19.5 //Required heat transfer area (m^2) +Cmin = 4736.0 //Minimum capacitance rate (W/K) + +//Calculation: +DT1 = t2-t1 //Actual water temperature change ( F) +DT2 = T1 - t1 //Maximum water temperature change ( F) +E = DT1/DT2 //Effectiveness +NTU = (U*A)/Cmin //Number of transfer units + +//Result: +printf("The effectiveness is : %.3f .",E) +printf("The NTU is : %.3f",NTU) diff --git a/2510/CH16/EX16.5/Ex16_5.sce b/2510/CH16/EX16.5/Ex16_5.sce new file mode 100755 index 000000000..cdda6437e --- /dev/null +++ b/2510/CH16/EX16.5/Ex16_5.sce @@ -0,0 +1,25 @@ +//Variable declaration: +//From figure 16.13, for ideal countercurrent heat exchanger: +T1 = 150.0 //Inlet temperature of hot fluid ( F) +T2 = 100.0 //Outet temperature of hot fluid ( F) +t1 = 50.0 //Inlet temperature of cold fluid ( F) +t2 = 80.0 //Outet temperature of hot fluid ( F) +//From figure 16.14, for shell and tube exchanger: +T_1 = 50.0 //Inlet temperature of cold fluid ( F) +T_2 = 80.0 //Outet temperature of hot fluid ( F) +t_1 = 150.0 //Inlet temperature of hot fluid ( F) +t_2 = 100.0 //Outet temperature of hot fluid ( F) + +//Calculation: +DT1 = T1 - t2 //Temperature driving force 1 ( F) +DT2 = T2 - t1 //Temperature driving force 1 ( F) +DTlm1 = ((DT1-DT2)/log(DT1/DT2)) //Log mean temperature driving force for ideal countercurrent heat exchanger ( F) +P = (t2-t1)/(T1 - t1) //Dimensionless ratio P +R = (T1-T2)/(t2-t1) //Dimensionless ratio R +//From figure 16.7: +F = 0.925 //Correction Factor +DTlm2 = F*DTlm1 //Log mean temperature driving force for shell and tube exchanger ( F) + +//Result: +printf("The log mean temperature difference for ideal system is : %.1f F.",DTlm1) +printf("The log mean temperature difference for real system is : %.2f F.",DTlm2) diff --git a/2510/CH16/EX16.6/Ex16_6.sce b/2510/CH16/EX16.6/Ex16_6.sce new file mode 100755 index 000000000..0c4f47f3e --- /dev/null +++ b/2510/CH16/EX16.6/Ex16_6.sce @@ -0,0 +1,18 @@ +//Variable declaration: +T1 = 400.0 //Temperature of fluid entering the shell ( F) +T2 = 250.0 //Temperature of fluid leaving the shell ( F) +t1 = 100.0 //Temperature of fluid entering the tube ( F) +t2 = 175.0 //Temperature of fluid leaving the tube ( F) + +//Calculation: +DT1 = T1 - T2 //Temperature driving force 1 ( F) +DT2 = t2 - t1 //Temperature driving force 1 ( F) +DTlm1 = ((DT1-DT2)/log(DT1/DT2)) //Log mean temperature driving force for ideal countercurrent heat exchanger ( F) +P = (t2-t1)/(T1 - t1) //Dimensionless ratio P +R = (T1-T2)/(t2-t1) //Dimensionless ratio R +//From figure 16.8: +F = 0.985 //Correction factor +DTlm2 = F*DTlm1 //Log mean temperature driving force for shell and tube exchanger ( F) + +//Result: +printf("The log mean temperature difference between the hot fluid and the cold fluid is : %.1f F.",DTlm2) diff --git a/2510/CH16/EX16.7/Ex16_7.sce b/2510/CH16/EX16.7/Ex16_7.sce new file mode 100755 index 000000000..9d958a5d5 --- /dev/null +++ b/2510/CH16/EX16.7/Ex16_7.sce @@ -0,0 +1,22 @@ +//Variable declaration: +//From example 16.5: +P1 = 0.30 //Dimensionless ratio P +R1 = 1.67 //Dimensionless ratio R +//From example 16.6: +P2 = 0.30 //Dimensionless ratio P +R2 = 1.67 //Dimensionless ratio R + +//Calculation: +//Applying Equation 16.27: +F1 = 0.92 //Correction Factor +//Applying Equation 16.33: +F2 = 0.985 //Correction Factor +//From example 16.6: +LMTD1 = 59.4 //Log mean temperature driving force 1 for ideal countercurrent heat exchanger ( F) +LMTD2 = 108.0 //Log mean temperature driving force 2 for ideal countercurrent heat exchanger ( F) +DTlm1 = F1*LMTD1 //Log mean temperature driving force 1 for shell and tube exchanger ( F) +DTlm2 = F2*LMTD2 //Log mean temperature driving force 2 for shell and tube exchanger ( F) + +//Result: +printf("The log mean temperature difference for real system (in example 16.5) is : %.2f F.",DTlm1) +printf("The log mean temperature difference for real system (in example 16.6) is : %.1f F .",DTlm2) diff --git a/2510/CH16/EX16.8/Ex16_8.sce b/2510/CH16/EX16.8/Ex16_8.sce new file mode 100755 index 000000000..db26f8ad3 --- /dev/null +++ b/2510/CH16/EX16.8/Ex16_8.sce @@ -0,0 +1,20 @@ +//Variable declaration: +t2 = 75.0 //Temperature of water leaving the shell ( C) +t1 = 35.0 //Temperature of water enteringing the shell ( C) +T2 = 75.0 //Temperature of oil leaving the tube ( C) +T1 = 110.0 //Temperature of oil entering the tube ( C) +m = 1.133 //Mass flowrate of water (kg/s) +cp = 4180.0 //Heat capacity of water (J/kg.K) +F = 0.965 //Correction factor +U = 350.0 //Overall heat transfer coefficient (W/m^2.K) + +//Calculation: +Q = m*cp*(t2-t1) //Heat load (W) +DT1 = T1-t2 //Temperature driving force 1 ( C) +DT2 = T2-t1 //Temperature driving force 2 ( C) +DTlm1 = (DT1-DT2)/log(DT1/DT2)+273.0 //Countercurrent log-mean temperature difference (K) +DTlm2 = F*DTlm1 //Corrected log-mean temperature difference (K) +A = Q/(U*DTlm2) //Required heat transfer area (m^2) + +//Result: +printf("The required heat-transfer area is : %.3f m^2.",A) diff --git a/2510/CH17/EX17.1/Ex17_1.sce b/2510/CH17/EX17.1/Ex17_1.sce new file mode 100755 index 000000000..69e6d1ba3 --- /dev/null +++ b/2510/CH17/EX17.1/Ex17_1.sce @@ -0,0 +1,14 @@ +//Variable declaration: +w1 = 1.5 //Thicknessof fin (in) +L = 12.0 //Length of fin (in) +w2 = 0.1 //Thickness of fin(in) + +//Calculation: +Af = 2*w1*L //Face area of fin (in^2) +At = Af + L*w2 //Total area of fin (in^2) + +//Result: +printf("The face area of the fin is : %.0f in^2 ",Af) +printf("The face area of the fin is : %.2f ft^2 .",Af/12**2) +printf("The total area of the fin is : %.1f in^2 .",At) +printf("The total area of the fin is : %.3f ft^2 .",At/12**2) diff --git a/2510/CH17/EX17.10/Ex17_10.sce b/2510/CH17/EX17.10/Ex17_10.sce new file mode 100755 index 000000000..6743c6203 --- /dev/null +++ b/2510/CH17/EX17.10/Ex17_10.sce @@ -0,0 +1,38 @@ +//Variable declaration: +Do = 2.5/100 //Outside diameter of tube (m) +t = 1/10**3 //Thickness of fin (m) +T = 25 //Fluid temperature ( C) +Tb = 170 //Surface temperature ( C) +h = 130 //Heat transfer coefficient (W/m^2.K) +k = 200 //Thermal conductivity of fin (W/m.K) +rf = 2.75/100 //Outside radius of fin (m) + +//Calculation: +ro = Do/2 //Radius of tube (m) +Ab = 2*%pi*ro*t //Area of the base of the fin (m^2) +Te = Tb-T //Excess temperature at the base of the fin (K) +Q1 = h*Ab*Te //Total heat transfer rate without the fin (W) +Bi = h*(t/2)/k //Biot number +L = rf-ro //Fin height (m) +rc = rf+t/2 //Corrected radius (m) +Lc = L+t/2 //Corrected height (m) +Ap = Lc*t //Profile area (m^2) +Af = 2*%pi*(rc**2-ro**2) //Fin surface area (m^2) +Qm = h*Af*Te //Maximum fin heat transfer rate (W) +A = sqrt(Lc**3*h/(k*Ap)) //Abscissa of fin efficiency +C = rf/ro //Curve parameter of fin efficiency +//From figure 17.4: +nf = 0.86 //Fin efficiency +Qf = nf*Qm //Fin heat transfer rate (W) +R = Te/Qf //Fin resistance (K/W) + +//Result: +printf("1. The heat transfer rate without the fin is : %.2f W .",Q1) +printf("Or, the heat transfer rate without the fin is : %.0f Btu/h .",Q1*3.412) +printf("2. The corrected length is : %.4f m .",Lc) +printf("3. The outer radius is : %.3f m ",rc) +printf("4. The maximum heat transfer rate from the fin is : %.2f W .",Qm) +printf("5. The fin efficiency is : %.0f %%",nf*100) +printf("6. The fin heat transfer rate is : %.0f %%",Qf) +printf("Or, the fin heat transfer rate is : %.0f %%",Qf*3.412) +printf("7. The fin thermal resistance is : %.2f K/W .",R) diff --git a/2510/CH17/EX17.11/Ex17_11.sce b/2510/CH17/EX17.11/Ex17_11.sce new file mode 100755 index 000000000..66232cc78 --- /dev/null +++ b/2510/CH17/EX17.11/Ex17_11.sce @@ -0,0 +1,13 @@ +//Variable declaration: +//From example 17.10: +Qf = 64 //Fin heat transfer rate (W) +Q1 = 1.48 //Total heat transfer rate without the fin (W) + +//Calculation: +E = Qf/Q1 //Fin effectiveness + +//Result: +printf("The fin effectiveness is : %.1f",E) +if E>2 then + printf("Hence, the use of the fin is justified.") +end diff --git a/2510/CH17/EX17.12/Ex17_12.sce b/2510/CH17/EX17.12/Ex17_12.sce new file mode 100755 index 000000000..5ef496cff --- /dev/null +++ b/2510/CH17/EX17.12/Ex17_12.sce @@ -0,0 +1,32 @@ +//Variable declaration: +w = 1 //Length of tube (m) +S = 10/10**3 //Fin patch (m) +//From example 17.10: +t = 1/10**3 //Thickness of fin (m) +ro = 0.0125 //Radius of tube (m) +Af = 3.94*10**-3 //Fin surface area (m^2) +Tb = 145 //Excess temperature at the base of the fin (K) +h = 130 //Heat transfer coefficient (W/m^2.K) +Qf = 64 //Fin heat transfer rate (W) + +//Calculation: +Nf = w/S //Number of fins in tube length +wb = w-Nf*t //Unfinned base length (m) +Ab = 2*%pi*ro*wb //Unfinned base area (m^2) +At =Ab+Nf*Af //Total transfer surface area (m^2) +Qt = h*(2*%pi*ro*w*Tb) //Total heat rate without fins (W) +Qb = h*Ab*Tb //Heat flow rate from the exposed tube base (W) +Qft = Nf*Qf //Heat flow rate from all the fins (W) +Qt2 = Qb+Qft //Total heat flow rate (W) +Qm = h*At*Tb //Maximum heat transfer rate (W) +no = Qt2/Qm //Overall fin efficiency +Eo = Qt2/Qt //Overall effectiveness +Rb = 1/(h*Ab) //Thermal resistance of base (K/W) +Rf = 1/(h*Nf*Af*no) //Thermal resistance of fins (K/W) + +//Result: +printf("1. The total surface area for heat transfer is : %.3f m^2 .",At) +printf("2. The exposed tube base total heat transfer rate is : %.1f W .",Qb) +printf("Or, the exposed tube base total heat transfer rate is : %.0f Btu/h .",Qb*3.412) +printf("3. The overall efficiency of the surface is : %.1f %%",no*100) +printf("4. The overall surface effectiveness is : %.2f .",Eo) diff --git a/2510/CH17/EX17.13/Ex17_13.sce b/2510/CH17/EX17.13/Ex17_13.sce new file mode 100755 index 000000000..4bf8728ee --- /dev/null +++ b/2510/CH17/EX17.13/Ex17_13.sce @@ -0,0 +1,32 @@ +//Variable declaration: +w = 1 //Width of single of fin (m) +t = 2/10**3 //Fin base thickness (m) +l = 6/10**3 //Fin length thickness (m) +T1 = 250 //Surface temperature ( C) +T2 = 20 //Ambient air temperature ( C) +h = 40 //Surface convection coefficient (W/m^2.K) +k = 240 //Thermal conductivity of fin (W/m.K) + +//Calculation: +Ab = t*w //Base area of the fin (m^2) +Te = T1-T2 //Excess temperature at the base of the fin (K) +Qw = h*Ab*Te //Heat transfer rate without a fin (W) +Af = 2*w*(sqrt(l**2-(t/2)**2)) //Fin surface area (m^2) +Qm = h*Af*Te //Maximum heat transfer rate (m^2) +Bi = h*(t/2)/k //Biot number +Lc = l //Corrected length (m) +Ap = l*t/2 //Profile area (m^2) +A = sqrt((Lc**3*h)/k*Ap) //Abscissa for the fin efficiency figure +//From figure 17.4: +nf = 0.99 //Fin efficiency +Qf = nf*Qm //Fin heat transfer rate (W) +R = Te/Qf //Fin thermal resistance (K/W) +E = Qf/Qw //Fin effectiveness +Qm = round(Qm*10**-1)/10**-1 + +//Result: +printf("1. The heat transfer rate without the fin is : %.1f W .",Qw) +printf("2. The maximum heat transfer rate from the fin is : %f W .",Qm) +printf("3. The fin efficiency is : %.0f %%",nf*100) +printf(" The fin thermal resistance is : %.1f C/W .",R) +printf(" The fin effectiveness is : %.1f .",E) diff --git a/2510/CH17/EX17.14/Ex17_14.sce b/2510/CH17/EX17.14/Ex17_14.sce new file mode 100755 index 000000000..aa51305e2 --- /dev/null +++ b/2510/CH17/EX17.14/Ex17_14.sce @@ -0,0 +1,13 @@ +//Variable declaration: +//From example 17.13: +Qf = 108.9 //Fin heat transfer rate (W) +Qw = 18.4 //Total heat transfer rate without the fin (W) + +//Calculation: +E = Qf/Qw //Fin effectiveness + +//Result: +printf("The fin effectiveness is : %.2f .",E) +if E>2 then + printf("Hence, the use of the fin is justified.") +end diff --git a/2510/CH17/EX17.15/Ex17_15.sce b/2510/CH17/EX17.15/Ex17_15.sce new file mode 100755 index 000000000..8a282671c --- /dev/null +++ b/2510/CH17/EX17.15/Ex17_15.sce @@ -0,0 +1,38 @@ +//Variable declaration: +Do = 50/10**3 //Outside diameter of tube (m) +t = 4/10**3 //Thickness of fin (m) +T = 20 //Fluid temperature ( C) +Tb = 200 //Surface temperature ( C) +h = 40 //Heat transfer coefficient (W/m^2.K) +k = 240 //Thermal conductivity of fin (W/m.K) +l = 15/10**3 //Length of fin (m) + +//Calculation: +ro = Do/2 //Radius of tube (m) +rf = ro+l //Outside radius of fin (m) +Ab = 2*%pi*ro*t //Area of the base of the fin (m^2) +Te = Tb-T //Excess temperature at the base of the fin (K) +Q1 = h*Ab*Te //Total heat transfer rate without the fin (W) +Bi = h*(t/2)/k //Biot number +L = rf-ro //Fin height (m) +rc = rf+t/2 //Corrected radius (m) +Lc = L+t/2 //Corrected height (m) +Ap = Lc*t //Profile area (m^2) +Af = 2*%pi*(rc**2-ro**2) //Fin surface area (m^2) +Qm = h*Af*Te //Maximum fin heat transfer rate (W) +A = sqrt(Lc**3*h/(k*Ap)) //Abscissa of fin efficiency +C = rf/ro //Curve parameter of fin efficiency +//From figure 17.4: +nf = 0.97 //Fin efficiency +Qf = nf*Qm //Fin heat transfer rate (W) +R = Te/Qf //Fin resistance (K/W) +E = Qf/Q1 //Fin effectiveness + +//Result: +printf("The fin efficiency is : %.0f %%",nf*100) +printf("The fin thermal resistance is : %.1f C/W.",R) +printf("The fin effectiveness is : %.2f .",E) +printf("The maximum heat transfer rate from a single fin is : %.2f W .",Qm) +if E>2 then + printf("Since Ef = FCP>2, the use of the fin is justified.") +end diff --git a/2510/CH17/EX17.16/Ex17_16.sce b/2510/CH17/EX17.16/Ex17_16.sce new file mode 100755 index 000000000..d9192b1de --- /dev/null +++ b/2510/CH17/EX17.16/Ex17_16.sce @@ -0,0 +1,31 @@ +//Variable declaration: +Nf = 125 //Array of fins per meter +w = 1 //Length of fin (m) +//From example 17.15: +t = 4/10**3 //Thickness of fin (m) +Do = 50/10**3 //Outside diameter of tube (m) +Af = 7.157*10**-3 //Fin surface area (m^2) +h = 40 //Heat transfer coefficient (W/m^2.K) +DTb = 180 //Excess temperature at the base of the fin (K) +Qf = 50 //Fin heat transfer rate (W) + +//Calculation: +ro = Do/2 //Radius of tube (m) +wb = w-Nf*t //Unfinned exposed base length (m) +Ab = 2*%pi*ro*wb //Area of the base of the fin (m^2) +At = Ab+Nf*Af //Total heat transfer surface area (m^2) +Qw = h*(2*%pi*ro*w)*DTb //Heat rate without fin (W) +Qb = h*Ab*DTb //Heat rate from the base (W) +Qft = Nf*Qf //Heat rate from the fin (W) +Qt = Qb+Qft //Total heat rate (W) +Qm = h*At*DTb //Maximum heat transfer rate (W) +n = Qt/Qm //Overall fin efficiency +E = Qt/Qw //Overall fin effectiveness +Rb = 1/(h*Ab) //Thermal resistance of base ( C/W) +Rf = 1/(h*Nf*Af*n) //Thermal resistance of fin ( C/W) + +//Result: +printf("The rate of heat transfer per unit length of tube is : %.1f W .",Qt) +printf("Or, the rate of heat transfer per unit length of tube is : %.2f kW .",Qt/10**3) +printf("The overall fin efficiency is : %.1f %%",n*100) +printf("The overall fin effectiveness is : %.2f .",E) diff --git a/2510/CH17/EX17.17/Ex17_17.sce b/2510/CH17/EX17.17/Ex17_17.sce new file mode 100755 index 000000000..22af4a2a7 --- /dev/null +++ b/2510/CH17/EX17.17/Ex17_17.sce @@ -0,0 +1,2 @@ +//Variable declaration: +printf('Analytical Solution') diff --git a/2510/CH17/EX17.18/Ex17_18.sce b/2510/CH17/EX17.18/Ex17_18.sce new file mode 100755 index 000000000..d87459d37 --- /dev/null +++ b/2510/CH17/EX17.18/Ex17_18.sce @@ -0,0 +1,17 @@ +//Variable declaration: +//From example 17.18: +T = 250 //Base temperature of fin ( F) +h = 15 //Convection coefficient of heat transfer (Btu/h.ft. F) +w = 1 //Base width of fin (ft) +t = 1 //Thickness of fin (in) +H = 1/8 //Height of fin (in) +l = 1 //Length of fin (in) +Q = 357.2 //Heat transfer rate (Btu/h.ft) + +//Calculation: +A = (l*w+t*w+H*w)/12 //Heat transfer area of fin (ft^2) +Qm = h*A*(T-70) //Maximum heat transfer rate (Btu/h.ft) +n = Q/Qm*100 //Fin efficiency + +//Result: +printf("The fin efficiency is : %.1f %%",n) diff --git a/2510/CH17/EX17.3/Ex17_3.sce b/2510/CH17/EX17.3/Ex17_3.sce new file mode 100755 index 000000000..9556ddecd --- /dev/null +++ b/2510/CH17/EX17.3/Ex17_3.sce @@ -0,0 +1,11 @@ +//Variable declaration: +rf = 6.0/12.0 //Outside radius of fin (ft) +ro = 4.0/12.0 //Outside radius of %pipe (ft) +t = 0.1/12.0 //Thickness of fin (ft) + +//Calculation: +Af = 2*%pi*(rf**2-ro**2) //Face area of fin (ft^2) +At = Af + 2*%pi*rf*t //Total area of fin (ft^2) + +//Result: +printf("The total fin area is : %.3f ft^2 .",At) diff --git a/2510/CH17/EX17.4/Ex17_4.sce b/2510/CH17/EX17.4/Ex17_4.sce new file mode 100755 index 000000000..87c3206d3 --- /dev/null +++ b/2510/CH17/EX17.4/Ex17_4.sce @@ -0,0 +1,15 @@ +//Variable declaration: +L = 3.0*0.0254 //Height of fin (m) +t = 1.0*0.0254 //Thickness of fin (m) +h = 15.0 //Heat transfer coefficient (W/m^2.K) +k = 300.0 //Thermal conductivity (W/m.K) + +//Calculation: +Lc = L + t/2.0 //Corrected height of fin (m) +Ap = Lc*t //Profile area of fin (m^2) +x = sqrt((Lc**3*h)/(k*Ap)) //x-coordinate of figure 17.3 +//From figure 17.3: +nf = 98.0 //Fin efficiency + +//Result: +printf("The fin efficiency is : %f %%",nf) diff --git a/2510/CH17/EX17.5/Ex17_5.sce b/2510/CH17/EX17.5/Ex17_5.sce new file mode 100755 index 000000000..2ac673dba --- /dev/null +++ b/2510/CH17/EX17.5/Ex17_5.sce @@ -0,0 +1,10 @@ +//Variable declaration: +//From example 17.4: +X = 0.1246 //X-coordinate of figure 17.3 + +//Calculation: +//Applying equation (A) from Table 17.3: +Y = 4.5128*X**3 - 10.079*X**2 - 31.413*X + 101.47 + +//Result: +printf("The fin efficiency is : %.1f %%",Y) diff --git a/2510/CH17/EX17.6/Ex17_6.sce b/2510/CH17/EX17.6/Ex17_6.sce new file mode 100755 index 000000000..1ff551c5a --- /dev/null +++ b/2510/CH17/EX17.6/Ex17_6.sce @@ -0,0 +1,18 @@ +//Variable declaration: +w = 0.2/100.0 //Width of fin (m) +t = 0.2/100.0 //Thickness of fin (m) +L = 1.0/100.0 //Length of fin (m) +h = 16.0 //Heat transfer coefficient (W/m^2.K) +k = 400.0 //Thermal conductivity of fin (W/m.K) +Tc = 100.0 //Circuit temperature ( C) +Ta = 25.0 //Air temperature ( C) + +//Calculation: +P = 4*w //Fin cross-section parameter (m) +Ac = w*t //Cross-sectional area of fin (m^2) +Lc = L+Ac/P //Corrected height of fin (m) +m = sqrt((h*P)/(k*Ac)) //Location of minimum temperature (m^-1) +Q = (sqrt(h*P*k*Ac))*(Tc-Ta)*atan(h)*(m*Lc) //Heat transfer from each micro-fin (W) + +//Result: +printf("The heat transfer from each micro-fin is : %.2f W .",Q) diff --git a/2510/CH17/EX17.8/Ex17_8.sce b/2510/CH17/EX17.8/Ex17_8.sce new file mode 100755 index 000000000..f06516247 --- /dev/null +++ b/2510/CH17/EX17.8/Ex17_8.sce @@ -0,0 +1,56 @@ +//Variable declaration: +h1 = 13.0 //Air-side heat transfer coefficient (W/m^2.K) +A = 1.0 //Base wall area (m^2) +L = 2.5/100 //Length of steel fins (m) +L2 = 1.5/10**3 //Length of steel wall (m) +k = 13.0 //Thermal conductivity of fin (W/m.K) +k1 = 38.0 //Thermal conductivity of steel wall (W/m.K) +h2 = 260.0 //Water side heat transfer coefficient (W/m^2.K) +T4 = 19.0 //Air temperature ( C) +T1 = 83.0 //Water temperature ( C) +t = 1.3/10**3 //Thickness of steel fins (m) +w = 1.0 //Width of wall (m) +S = 1.3/100 //Fin pitch(m) + +//Calculation: +R1 = 1/(h1*A) //Air resistance ( C/W) (part 1) +R2 = L2/(k1*A) //Conduction resistance ( C/W) +R3 = 1/(h2*A) //Water resistance ( C/W) +Rt = (R1+R3) //Total resistance ( C/W) (part 2) +Q = (T1-T4)/Rt //Total heat transfer (W) +Nf = 1/S //Number of fins (part 3) +Lbe = w - Nf*t //Unfinned exposed base surface +Abe = w*Lbe //Exposed base surface area (m^2) +Lc = L+t/2 //Corrected length (m) +Ap = Lc*t //Profile area (m^2) +Af = 2*w*Lc //Fin surface area (m^2) +Bi = h1*(t/2)/k1 //Biot number +a = sqrt(Lc**3*h1/(k*Ap)) //Abscissa of the fin efficiency +//From figure 17.3: +nf = 0.88 //Fin efficiency +Rb = 1/(h1*Abe) //Air thermal resistance of base wall ( C/W) +Rf = 1/(h1*Nf*Af*nf) //Air thermal resistance of fins ( C/W) +RT1 = 1/(1/Rb+1/Rf) //Total outside resistance of the fin array ( C/W) +Rt3 = RT1+R3 //Total resistance on air side fins ( C/W) +Qt = (T1-T4)/Rt3 //Heat transfer rate on air side fins (W) +I = (Qt/Q - 1)*100 //Percent increase in heat transfer rate to air side fins (W) +A = sqrt(Lc**3*h2/(k1*Ap)) //Abscissa of the new fin efficiency (part 4) +//From figure 17.3: +nf2 = 38.0 //New fin efficiency +Rb2 = 1/(h2*Abe) //Thermal resistance of base wall ( C/W) +Rf2 = 1/(h2*Nf*Af*nf2) //Thermal resistance of fins ( C/W) +Rt4 = 1/(1/Rb2+1/Rf2) //Total resistance of the finned surface ( C/W) +Rt5 = R1+Rt4 //Total resistance on water side fins ( C/W) +QT1 = (T1-T4)/Rt5 //Heat transfer rate on water side fins (W) +I2 = (QT1/Q - 1)*100 //Percent increase in heat transfer rate to water side fins (W) + +//Result: +if (R2<R1 | R2<R3) then + printf("1. The conduction resistance may be neglected.") +else + printf("1. The conduction resistance can not be neglected.") +end +printf("2. The rate of heat transfer from water to air is : %.1f W .",Q) +printf("3. The percent increase in steady-state heat transfer rate by adding fins to the air side of the plane wall is : %.1f %%",I) +printf("4. The percent increase in steady-state heat transfer rate by adding fins to the water side of the plane wall is : %.1f %%",I2) +printf("____There is a calculation mistake in book in calculating Qt(83-19/0.0214 = 2999), hence slight differences in answer______") diff --git a/2510/CH18/EX18.10/Ex18_10.sce b/2510/CH18/EX18.10/Ex18_10.sce new file mode 100755 index 000000000..f4302600a --- /dev/null +++ b/2510/CH18/EX18.10/Ex18_10.sce @@ -0,0 +1,23 @@ +//Variable declaration: +T1 = 2000 //Hot gas temperature ( F) +T2 = 550 //Cool gas temperature ( F) +T3 = 330 //Steam temperature ( F) +T4 = 140 //Water temperature ( F) +m = 30000 //Mass flow rate of steam (lb/h) +cp = 0.279 //Average heat capacity of gas (Btu/lb. F) +N = 800 //Number of boiler tubes + +//Calculation: +DT = (T1-T3)/(T2-T3) //Temperature difference ratio +Tav = (T1+T2)/2 //Average gas temperature ( F) +//From steam tables (Appendix): +hs = 1187.7 //Steam enthalpy (Btu/lb) +hw = 107.89 //Water enthalpy (Btu/lb) +Q = m*(hs-hw) //Heat duty (Btu/h) +mh = Q/cp*(T1-T2) //Mass flow rate of gas (lb/h) +x = mh/N //Gas mass flow rate per tube (lb/h) +//From figure 18.5: +L = 15 //Length of boiler tubes (ft) + +//Result: +printf("The length of boiler tubes is : %f ft .",L) diff --git a/2510/CH18/EX18.12/Ex18_12.sce b/2510/CH18/EX18.12/Ex18_12.sce new file mode 100755 index 000000000..e93d703e2 --- /dev/null +++ b/2510/CH18/EX18.12/Ex18_12.sce @@ -0,0 +1,30 @@ + +//Variable declaration: +T1 = 1800 //Hot gas temperature ( F) +T2 = 500 //Cool gas temperature ( F) +//From steam tables: +Tw = 312 //Boiling point of water at 80 psia ( F) +m1 = 120000 //Mass flow rate of flue gas (lb/h) +D = 2/12 //Inside diameter of tube (ft) +cp = 0.26 //Average heat capacity of flue gas (Btu/lb. F) + +//Calculation: +DT = (T1-Tw)/(T2-Tw) //Temperature difference ratio +Tav = (T1+T2)/2 //Average gas temperature ( F) +//From figure 18.4: +x = 150 //Gas mass flow rate per tube (m/N) (lb/h) +N = m1/x //Number of tubes +L = 21.5 //Length of tubes (ft) +A = N*L*D //Total heat transfer area (ft^2) +Q = m1*cp*(T1-T2) //Heat duty (Btu/h) +//From steam tables (Appendix): +hs = 1183.1 //Steam enthalpy at 80 psia (Btu/lb) +hw = 168.1 //Water enthalpy at 200 F (Btu/lb) +m2 = Q/(hs-hw) //Mass flow rate of water (lb/h) +m2 = round(m2*10**-4)/10**-4 + +//Result: +printf("The required heat transfer area is : %.0f ft^2 .",A) +printf("The tube length is : %f ft .",L) +printf("The heat duty is : %.2f x 10^7 .",Q/10**7) +printf("The water mass flow rate is : %f lb/h .",m2) diff --git a/2510/CH18/EX18.18/Ex18_18.sce b/2510/CH18/EX18.18/Ex18_18.sce new file mode 100755 index 000000000..3ba48e148 --- /dev/null +++ b/2510/CH18/EX18.18/Ex18_18.sce @@ -0,0 +1,24 @@ +//Variable declaration: +m1 = 144206 //Mass flow rate of flue gas (lb/h) +cp = 0.3 //Average flue gas heat capacity (Btu/lb. F) +T1 = 2050 //Initial temperature of gas ( F) +T2 = 560 //Final temperature of gas ( F) +T3 = 70 //Ambient air temperature ( F) + +//Calculation: +Q = m1*cp*(T1-T2) //Duty rate (Btu/h) +//From appendix: +cpa = 0.243 //Average ambient air heat capacity 70 F (Btu/lb. F) +MW = 29 //Molecular weight of air at 70 F +Q5 = round(Q*10**-5)/10**-5 +ma = Q5/(cpa*(T2-T3)) //Mass of air required (lb/h) +m2 = round(ma)/MW //Moles of air required (lb mol/h) +m3 = round(ma)*13.32 //Volume of air required (ft^3/h) +ma = round(ma*10**-2)/10**-2 +m2 = round(m2*10**-1)/10**-1 +m3 = round(m3*10**-3)/10**-3 + +//Result: +printf("The mass of air required is : %f lb/h .",ma) +printf("The moles of air required is : %f lb mol/h .",m2) +printf("The volume of air required is : %f ft^3/h .",m3) diff --git a/2510/CH18/EX18.19/Ex18_19.sce b/2510/CH18/EX18.19/Ex18_19.sce new file mode 100755 index 000000000..5664a05fb --- /dev/null +++ b/2510/CH18/EX18.19/Ex18_19.sce @@ -0,0 +1,20 @@ +//Variable declaration: +//From example 18.19: +m1 = 144200 //Mass flow rate of flue gas (lb/h) +m2 = 541700 //Mass flow rate of air (lb/h) +R = 0.73 //Universal gas constant (psia.ft^3/lbmol. R) +P = 1 //Absolute pressure (psia) +T = 1020 //Absolute temperature ( R) +MW = 29 //Molecular weight of air +t = 1.5 //Residence time (s) + +//Calculation: +m = m1+m2 //Total mass flow rate of the gas (lb/h) +q = m*R*T/(P*MW) //Volumetric flow at 560 F (ft^3/h) +V = q*t/3600 //Volume of tank (ft^3) +m = round(m*10**-2)/10**-2 + +//Result: +printf("The total mass flow rate of the gas is : %f lb/h .",m) +printf("The volumetric flow at 560 F is : %.2f x 10^7 ft^3/h",q/10**7) +printf("The volume of tank is : %.0f ft^3 .",V) diff --git a/2510/CH18/EX18.2/Ex18_2.sce b/2510/CH18/EX18.2/Ex18_2.sce new file mode 100755 index 000000000..298ac5bd3 --- /dev/null +++ b/2510/CH18/EX18.2/Ex18_2.sce @@ -0,0 +1,19 @@ +//Variable declaration: +T1 = 25 //Temperature of H2SO4 ( C) +m = 50+200 //Mass of H2SO4 (lb) +//From figure 18.2: +W1 = 50+100 //Weight of H2SO4 (lb) +W2 = 100 //Weight of H2O (lb) + +//Calculation: +m = W1/(W1+W2)*100 //Percent weight of H2SO4 (%) +m2 = W1+W2 //Mass of mixture (lb) +//From fgure 18.2: +T2 = 140 //Final temperature between the 50% solution and pure H2SO4 at 25 C ( F) +h1 = -86 //Specific heat capacity of H2O (Btu/lb) +h2 = -121.5 //Specific heat capacity of H2SO4 (Btu/lb) +Q = m2*(h2-h1) //Heat transferred (Btu) + +//Result: +printf("The final temperature between the 50%% solution and pure H2SO4 at 25 C is : %.0f F .",T2) +printf("The heat transferred is : %.0f Btu .",Q) diff --git a/2510/CH18/EX18.20/Ex18_20.sce b/2510/CH18/EX18.20/Ex18_20.sce new file mode 100755 index 000000000..4ca382903 --- /dev/null +++ b/2510/CH18/EX18.20/Ex18_20.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//Fro example 18.20: +V = 7335 //Volume of tank (ft^3) + +//Calculation: +D = (4*V/%pi)**(1/3) //Diameter of tank (ft) +H = D //Height of tube (ft) + +//Result: +printf("The diameter of tank is : %.2f ft .",H) +printf("The height of tube is : %.2f ft .",D) diff --git a/2510/CH18/EX18.21/Ex18_21.sce b/2510/CH18/EX18.21/Ex18_21.sce new file mode 100755 index 000000000..392267b1d --- /dev/null +++ b/2510/CH18/EX18.21/Ex18_21.sce @@ -0,0 +1,17 @@ +//Variable declaration: +m1 = 144206 //Mass flow rate of flue gas (lb/h) +cp1 = 0.3 //Average heat capacities of the flue gas (Btu/lb F) +cp2 = 0.88 //Average heat capacities of the solid (Btu/lb F) +//From example 18.18: +T1 = 550 //Initial temperature of gas ( F) +T2 = 2050 //Final temperature of gas ( F) +T3 = 70 //Initial temperature of solid ( F) +T4 = 550-40 //Final temperature of solid ( F) + +//Calculation: +Dhf = m1*cp1*(T2-T1) //For the flue gas, the enthalpy change for one hour of operation (Btu) +Dhs = round(Dhf*10**-4)/10**-4 //For the solids, the enthalpy change for one hour of operation (Btu) +m2 = Dhs/(cp2*(T4-T3)) //Mass of solid (lb) + +//Result: +printf("The mass of solid is : %.0f lb .",m2) diff --git a/2510/CH18/EX18.22/Ex18_22.sce b/2510/CH18/EX18.22/Ex18_22.sce new file mode 100755 index 000000000..f2a0c1083 --- /dev/null +++ b/2510/CH18/EX18.22/Ex18_22.sce @@ -0,0 +1,26 @@ +//Variable declaration: +//From example 18.21: +m = 144206 //Mass flow rate of flue gas (lb/h) +cp = 0.3 //Average heat capacities of the flue gas (Btu/lb F) +T1 = 2050 //Initial temperature of gas ( F) +T2 = 180 //Final temperature of gas ( F) +T3 = 60 //Ambient air temperature ( F) +U = 1.5 //Overall heat transfer coefficient for cooler (Btu/h.ft^2. F) +MW = 28.27 //Molecular weight of gas +R = 379 //Universal gas constant (psia.ft^3/lbmol. R) +v = 60 //Duct or pipe velcity at inlet (2050 F) (ft/s) +pi = %pi + +//Calculation: +Q = m*cp*(T1-T2) //Heat duty (Btu/h) +DTlm = ((T1-T3)-(T2-T3))/log((T1-T3)/(T2-T3)) //Log-mean temperature difference ( F) +A1 = round(Q * 10**-5)/10**-5/(U*round(DTlm)) //Radiative surface area (ft^2) +q = m*R*(T1+460)/(T3+460)/MW //Volumetric flow at inlet (ft^3/h) +A2 = q/(v*3600) //Duct area (ft^2) +D = sqrt(A2*4/pi) //Duct diameter (ft) +L = A1/(pi*D) //Length of required heat exchange ducting (ft) +A1 = round(A1*10**-1)/10**-1 + +//Result: +printf(" The radiative surface area required is : %f ft^2 .",A1) +printf(" The length of required heat exchange ducting is : %.0f ft .",L) diff --git a/2510/CH18/EX18.3/Ex18_3.sce b/2510/CH18/EX18.3/Ex18_3.sce new file mode 100755 index 000000000..4f40560d0 --- /dev/null +++ b/2510/CH18/EX18.3/Ex18_3.sce @@ -0,0 +1,22 @@ +//Variable declaration: +F = 10000 //Mass flow rate of NaOH (lb/h) +C1 = 10 //Old concentration of NaOH solution (%) +C2 = 75 //New concentration of NaOH solution (%) +h1 = 1150 //Enthalpy of saturated steam at 14.7 psia (Btu/lb) +U = 500 //Overall heat transfer coefficient (Btu/h.ft^2. F) +T1 = 212 //Absolute temperature of evaporator ( F) +T2 = 340 //Saturated steam temperature ( F) + +//Calculation: +L = F*(C1/100)/(C2/100) //Flow rate of steam leaving the evaporator (lb/h) +V = F-L //Overall material balance (lb/h) +//From figure 18.3: +hF = 81 //Enthalpy of solution entering the unit (Btu/lb) +hL = 395 //Enthalpy of the 75% NaOH solution (Btu/lb) +Q = round(V)*h1+round(L)*hL-F*hF //Evaporator heat required (Btu/h) +A = Q/(U*(T2-T1)) //Area of the evaporaor (ft^2) +Q = round(Q*10**-2)/10**-2 + +//Result: +printf("The heat transfer rate required for the evaporator is : %f Btu/h ",Q) +printf("The area requirement in the evaporator is : %.1f ft^2 .",A) diff --git a/2510/CH18/EX18.4/Ex18_4.sce b/2510/CH18/EX18.4/Ex18_4.sce new file mode 100755 index 000000000..c4dcf90f5 --- /dev/null +++ b/2510/CH18/EX18.4/Ex18_4.sce @@ -0,0 +1,19 @@ +//Variable declaration: +U1 = 240 //Overall heat transfer coefficient for first effect (Btu/h.ft^2. F) +U2 = 200 //Overall heat transfer coefficient for second effect (Btu/h.ft^2. F) +U3 = 125 //Overall heat transfer coefficient for third effect (Btu/h.ft^2. F) +A1 = 125 //Heating surface area in first effect (ft^3) +A2 = 150 //Heating surface area in second effect (ft^3) +A3 = 160 //Heating surface area in third effect (ft^3) +T1 = 400 //Condensation stream temperature in the first effect ( F) +T2 = 120 //Vapor leaving temperature in the first effect ( F) + +//Calculation: +R1 = 1/(U1*A1) //Resistance across first effect +R2 = 1/(U2*A2) //Resistance across second effect +R3 = 1/(U3*A3) //Resistance across third effect +R = R1+R2+R3 //Total resistance +DT1 = (R1/R)*(T1-T2) //Temperature drop across the heating surface in the first effect ( F) + +//Result: +printf("The temperature drop across the heating surface in the first effect is : %.0f F .",DT1) diff --git a/2510/CH18/EX18.6/Ex18_6.sce b/2510/CH18/EX18.6/Ex18_6.sce new file mode 100755 index 000000000..60d79b610 --- /dev/null +++ b/2510/CH18/EX18.6/Ex18_6.sce @@ -0,0 +1,32 @@ +//Variable declaration: +F = 5000 //Mass of soltuion fed in the evaporator (lb) +xF = 2/100 //Concentration of feed +xL = 5/100 //Concentration of liquor +U = 280 //Overall heat transfer coefficient (Btu/h.ft^2. F) +//From figure 18.1 & 18.3: +TF = 100 //Feed temperature ( F) +TS = 227 //Steam temperature ( F) +TV = 212 //Vapour temperature ( F) +TL = 212 //Liquor temperature ( F) +TC = 227 //Condensate temperature ( F) + +//Calculation: +//From steam tables: +hF = 68 //Enthalpy of feed (Btu/lb) +hL = 180 //Enthalpy of liquor (Btu/lb) +hV = 1150 //Enthalpy of vapour (Btu/lb) +hS = 1156 //Enthalpy of steam (Btu/lb) +hC = 195 //Enthalpy of condensate (Btu/lb) +s1 = F*xF //Total solids in feed (lb) +w = F-s1 //Total water in feed (lb) +s2 = F*xF //Total solids in liquor (lb) +L = s2/xL //Total water in liquor (lb) +V = F-L //Overall balance (lb) +S = (V*hV+L*hL-F*hF)/(hS-hC) //Mass of steam (lb) +Q = S*(hS-hC) //Total heat requirement (Btu) +A = Q/(U*(TS-TL)) //Required surface aea (ft^2) + +//Result: +printf("The mass of vapor produced is : %.0f lb .",V) +printf("The total mass of steam required is : %.0f lb .",S) +printf("The surface area required is : %.0f ft^2 .",A) diff --git a/2510/CH18/EX18.7/Ex18_7.sce b/2510/CH18/EX18.7/Ex18_7.sce new file mode 100755 index 000000000..68b181326 --- /dev/null +++ b/2510/CH18/EX18.7/Ex18_7.sce @@ -0,0 +1,35 @@ + +//Variable declaration: +F = 5000 //Mass flow rate of NaOH (lb/h) +xF = 20/100 //Old concentration of NaOH solution +TF = 100 //Feed temperature ( F) +xL = 40/100 //New concentration of NaOH solution +xv = 0 //Vapour concentration at x +yv = 0 //Vapour concentration at y +T1 = 198 //Boiling temperature of solution in the evaporator ( F) +T2 = 125 //Saturated steam temperature ( F) +U = 400 //Overall heat transfer coefficient (Btu/h.ft^2. F) +Ts = 228 //Steam temperature ( F) + +//Calculation: +//From steam tables at 228 F and 5 psig: +hS = 1156 //Enthalpy of steam (Btu/lb) +hC = 196 //Enthalpy of condensate (Btu/lb) +hV = hS-hC //Enthalpy of vapour (Btu/lb) +Tw = 125.4 //Boiling point of water at 4 in Hg absolute ( F) +hS2 = 1116 //Enthalpy of saturated steam at 125 F (Btu/lb) +hs = 0.46 //Heat capacity of superheated steam (Btu/lb. F) +//From figure 18.3: +hF = 55 //Enthalpy of feed (Btu/lb) +hL = 177 //Enthalpy of liquor (Btu/lb) +L = F*xF/xL //Mass of liquor (lb) +V = L //Mass of vapour (lb) +hV = hS2+hs*(T1-T2) //Enthalpy of vapour leaving the solution (Btu/lb) +S = (V*hV+L*hL-F*hF)/(hS-hC) //Mass flow rate of steam (lb/h) +Q = S*(hS-hC) //Total heat requirement (Btu) +A = Q/(U*(Ts-T1)) //Required heat transfer area (ft^2) +S = round(S*10**-1)/10**-1 + +//Result: +printf("The steam flow rate is : %f lb/h .",S) +printf("The required heat transfer area is : %.0f ft^2 .",A) diff --git a/2510/CH19/EX19.1/Ex19_1.sce b/2510/CH19/EX19.1/Ex19_1.sce new file mode 100755 index 000000000..5fddaac8c --- /dev/null +++ b/2510/CH19/EX19.1/Ex19_1.sce @@ -0,0 +1,23 @@ +//Variable declaration: +H = 2.5 //Height of wall (m) +W = 4 //Width of wall (m) +h = 11 //Convective heat transfer coefficient (W/m^2.K) +T1 = 24 //Outside surface temperature ( C) +T3 = -15 //Outside air temperature ( C) +L = 7.62/10**3 //Insulation thickness (m) +k = 0.04 //Thermal conductivity of wool (W/m.K) + +//Calculation: +A = H*W //Heat transfer area (m^2) +Q = h*A*(T1-T3) //Heat transfer rate (W) +Ri = L/(k*A) //Insuation resistance (K/W) +Rc = 1/(h*A) //Convective resitance (K/W) +R = Ri+Rc //Total resistance (K/W) +Qt = (T1-T3)/R //Revised heat transfer rate (Btu/h) + +//Result: +printf("1. The heat transfer rate without insulation is : %.0f W .",Q) +printf("Or, the heat transfer rate without insulation is : %.0f Btu/h .",Q*3.412) +printf("2. The revised heat transfer rate with insulation is : %.0f W .",Qt) +printf("Or, the revised heat transfer rate with insulation is : %.0f Btu/h .",Qt*3.412) +printf("There is a calculation mistake in book.") diff --git a/2510/CH19/EX19.10/Ex19_10.sce b/2510/CH19/EX19.10/Ex19_10.sce new file mode 100755 index 000000000..fe576f6e6 --- /dev/null +++ b/2510/CH19/EX19.10/Ex19_10.sce @@ -0,0 +1,45 @@ +//Variable declaration: +r1 = 1.1/100 //Inside radius of %pipe (m) +r2 = 1.3/100 //Outside radius of %pipe (m) +r3 = 3.8/100 //Outside radius of asbestos insulation (m) +L = 1 //Length of tube (m) +h1 = 190 //Heat transfer coefficient from ethylene glycol to the stainless steel %pipe (W/m^2.K) +k2 = 19 //Thermal conductivity of %pipe (W/m.K) +h2 = 14 //Outside heat transfer coefficient from the air to the surface of the insulation (W/m^2.K) +k3 = 0.2 //Thermal conductivity of asbestos (W/m.K) +T1 = 124 //Hot ethylene glycol temperature ( C) +T5 = 2 //Surrounding air temperature ( C) +k4 = 0.0242 //Thermal conductivity of air (W/m.K) + +//Calculation: +A1 = 2*%pi*r1*L //Inside surface area of %pipe (m^2) (part1) +A2 = 2*%pi*r2*L //Outside surface area of %pipe (m^2) +A3 = 2*%pi*r3*L //Outside surface area of asbestos insulation (m^2) +R1 = 1/(h1*A1) //Inside convection resistance ( C/W) +R2 = log(r2/r1)/(2*%pi*k2*L) //Conduction resistance through the tube ( C/W) +R3 = 1/(h2*A2) //Outside convection resistance ( C/W) +Rt1 = R1+R2+R3 //Total resistance without insulation ( C/W) +Q1 = (T1 - T5)/Rt1 //Heat transfer rate without insulation (W) +R4 = log(r3/r2)/(2*%pi*k3*L) //Conduction resistance associated with the insulation ( C/W) (part 2) +R5 = 1/(h2*A3) //Outside convection resistance ( C/W) +Rt2 = R1+R2+R4+R5 //Total rsistance with the insulation ( C/W) +Q2 = (T1-T5)/Rt2 //Heat transfer rate with the insulation (W) +U1 = 1/(Rt2*A1) //Overall heat transfer coefficient based on the inside area (W/m^2.K) (part 3) +U3 = 1/(Rt2*A3) //Overall heat transfer coefficient based on the outside area (W/m^2.K) (part 4) +T3 = T1-(R1+R2)*Q2 //Temperature at the steelu2013insulation interface ( C) (part 5) +Bi1 = h2*(2*r3)/k3 //Outside Biot number (part 6) +Bi2 = h1*(2*r1)/k2 //Inside Biot number +Nu = h1*(2*r1)/k4 //Nusselt number of the air +rlm = (r3-r2)/log(r3/r2) //Log mean radius of the insulation (m) (part 7) + +//Result: +printf("1. The rate of heat transfer without insulation is : %.1f W.",Q1) +printf("2. The rate of heat transfer with insulation is : %.1f W.",Q2) +printf("3. The overall heat transfer coefficient based on the inside area of the tube is : %.2f W/m^2.K .",U1) +printf("4. The overall heat transfer coefficient based on the outside area of the insulation is : %.1f W/m^2.K .",U3) +printf("5. The temperature, T3, at the steelu2013insulation interface is : %.1f C.",T3) +printf("6. The inside Biot numbers is : %.2f",Bi2) +printf(" The outside Biot numbers is : %.2f",Bi1) +printf(" The Nusselt number is : %.1f",Nu) +printf("7. The log mean radius of insulation is : %.2f cm.",rlm*100) +printf("There is a printing mistake in book for unit in part 7.") diff --git a/2510/CH19/EX19.11/Ex19_11.sce b/2510/CH19/EX19.11/Ex19_11.sce new file mode 100755 index 000000000..2dc08e48c --- /dev/null +++ b/2510/CH19/EX19.11/Ex19_11.sce @@ -0,0 +1,29 @@ +//Variable declaration: +h1 = 800 //Heat transfer coefficient for steam condensing inside coil (Btu/h.ft^2. F) +h2 = 40 //Heat transfer coefficient for oil outside coil (Btu/h.ft^2. F) +h3 = 40 //Heat transfer coefficient for oil inside tank wal (Btu/h.ft^2. F) +h4 = 2 //Heat transfer coefficient for outer tank wall to ambient air (Btu/h.ft^2. F) +k1 = 0.039 //Thermal conductivity of insulation layer (Btu/h.ft. F) +l1 = 2/12 //Thickness of insulation layer (ft) +D = 10 //Diameter of tank (ft) +H = 30 //Height of tank (ft) +k2 = 224 //Thermal conductivity of copper tube (Btu/h.ft. F) +l2 = (3/4)/12 //Thickness of insulation layer (ft) +T1 = 120 //Temperature of tank ( F) +T2 = 5 //Outdoor temperature ( F) + +//Calculation: +Uo1 = 1/(1/h3+(l1/k1)+1/h4) //Overall heat transfer coefficient for tank (Btu/h.ft^2. F) +At = %pi*(D+2*l1)*H //Surface area of tank (ft^2) +Q = Uo1*At*(T1-T2) //Heat transfer rate lost from the tank (Btu/h) +//From table 6.3: +l2 = 0.049/12 //Thickness of coil (ft) +A = 0.1963 //Area of 18 guage, 3/4-inch copper tube (ft^2/ft) +Uo2 = 1/(1/h2+(l2/k2)+1/h1) //Overall heat transfer coefficient for coil (Btu/h.ft^2. F) +//From steam tables: +Tst = 240 //Temperature for 10 psia (24.7 psia) steam ( F) +Ac = Q/(Uo2*(Tst-T1)) //Area of tube (ft^2) +L = Ac/A //Lengt of tube (ft) + +//Result: +printf("The length ofcopper tubing required is : %.1f ft",L) diff --git a/2510/CH19/EX19.12/Ex19_12.sce b/2510/CH19/EX19.12/Ex19_12.sce new file mode 100755 index 000000000..85aef843f --- /dev/null +++ b/2510/CH19/EX19.12/Ex19_12.sce @@ -0,0 +1,37 @@ +//Variable declaration: +//For 1-inch %pipe schedule 40: +Di = 1.049/12 //Inside diameter (ft) +Do = 1.315/12 //Outside diameter (ft) +L = 8000 //Length of %pipe (ft) +hi = 2000 //Heat transfer coefficient inside of the %pipe (Btu/h.ft^2. F) +ho = 100 //Outside heat transfer coefficient (Btu/h.ft. F) +kl = 0.01 //Thermal conductivity of insulation (Btu/h.ft. F) +T1 = 240 //Steam temperature ( F) +T2 = 20 //Air temperature ( F) +k = 24.8 //Thermal conductivity for steel (Btu/h.ft. F) +Dxl = ([3/8,1/2,3/4,1])/12 //thickness(ft) +amt = ([1.51,3.54,5.54,8.36])/6 //Cost per feet($) + +//Calculation: +D_ = (Do-Di)/log(Do/Di) //log-mean diameter of the %pipe (ft) +Dl = Do+2*(Dxl) //Insulation thickness (ft) +D_l = [ 0.13849079 0.14734319 0.16423045 0.18025404] +//D_l = (Dl-Do)/log(Dl/Do) //log mean diameter of %pipe (ft) +Dxw = (Do-Di)/2 //%pipe thickness (ft) +Rw = Dxw/(k*%pi*D_*L) //Wall resistance ((Btu/h. F)^-1) +Ri = 1/(hi*%pi*Di*L) //Inside steam convection resistance ((Btu/h. F)^-1) +Rl = [ 0.00089782 0.00112517 0.00151421 0.00183947] //Dxl/(kl*%pi*D_l*L) //Insulation resistance ((Btu/h. F)^-1) +Ro = [ 2.31217835e-06 2.06248306e-06 1.69614504e-06 1.44031623e-06] //1/(ho*%pi*Dl*L) //Outside air convection resistance ((Btu/h. F)^-1) +R = [ 0.00090054, 0.00112764,0.00151632,0.00184132] //Total resistance ((Btu/h. F)^-1) +Uo = [ 0.25675435 0.18290211 0.11185958 0.07822176] //Overall outside heat transfer coefficient (Btu/h.ft^2. F) +Ui = [ 0.50543158 0.40364002 0.30017609 0.24719271] //Overall inside heat transfer coefficient (Btu/h.ft^2. F) +dT = T1-T2 +Ai = %pi*Di*L //Inside area (ft^2) +Q = Ui*Ai*dT //Energy loss (Btu/h) +function [a] =energyPerDollar(Q1,Q2,amt1,amt2) + a = ((Q1-Q2)/(8000*(amt2-amt1))) +endfunction +//Results: +printf("Energy saved per dollar ingoing from 3/8 to 1/2 inch is : %.1f Btu/h.$",energyPerDollar(Q(1),Q(2),amt(1),amt(2))) +printf("Energy saved per dollar ingoing from 1/2 to 3/4 inch is : %.1f Btu/h.$",energyPerDollar(Q(2),Q(3),amt(2),amt(3))) +printf("Energy saved per dollar ingoing from 3/4 to 1 inch is : %.1f Btu/h.$",energyPerDollar(Q(3),Q(4),amt(3),amt(4))) diff --git a/2510/CH19/EX19.16/Ex19_16.sce b/2510/CH19/EX19.16/Ex19_16.sce new file mode 100755 index 000000000..a4709155e --- /dev/null +++ b/2510/CH19/EX19.16/Ex19_16.sce @@ -0,0 +1,17 @@ +//Variable declaration: +ki = 0.44 //Thermal conductivity of insulation (Btu/h.ft. F) +ho = 1.32 //Air flow coefficient (Btu/h.ft^2. F) +OD = 2 //Outside diameter of pipe (in) + +//Calculation: +rc = (ki/ho)*12 //Outer critical radius of insulation (in) +ro = OD/2 //Outside radius of pipe (in) +L = rc-ro //Critical insulation thickness (in) + +//Result: +printf("The outer critical radius of insulation is : %.0f in .",rc) +if ro<rc then + printf("Since, ro<rc, the heat loss will increase as insulation is added.") +else + printf("Sice, ro>rc, the heat loss will decrease as insulation is added.") +end diff --git a/2510/CH19/EX19.18/Ex19_18.sce b/2510/CH19/EX19.18/Ex19_18.sce new file mode 100755 index 000000000..74fe78441 --- /dev/null +++ b/2510/CH19/EX19.18/Ex19_18.sce @@ -0,0 +1,17 @@ +//Variable declaration: +Lf = 6/12 //Length of firebrick (ft) +kf = 0.61 //Thermal conductivity of firebrick (Btu/h.ft. F) +A = 480 //Surface area of wall (ft^2) +Lw = 8/12 //Length of rock wool (ft) +kw = 0.023 //Thermal conductivity of rock wool (Btu/h.ft. F) +T1 = 1900 //Temperature of insulation of firebrick ( F) +T2 = 140 //Temperature of insulation of rock wool ( F) + +//Calculation: +Rf = Lf/(kf*A) //Resistance of firebrick (h. F/Btu) +Rw = Lw/(kw*A) //Resistance of rock wool (h. F/Btu) +R = Rf+Rw //Total resitance (h. F/Btu) +Q = (T1-T2)/R //Heat loss through the wall (Btu/h) + +//Result: +printf("The heat loss through the wall is : %.0f Btu/h .",Q) diff --git a/2510/CH19/EX19.19/Ex19_19.sce b/2510/CH19/EX19.19/Ex19_19.sce new file mode 100755 index 000000000..ccfca3b4a --- /dev/null +++ b/2510/CH19/EX19.19/Ex19_19.sce @@ -0,0 +1,40 @@ + +//Variable declaration: +h1 = 1700 //Steam heat-transfer coefficient (Btu/h.ft^2. F) +h2 = 2 //Air heat-transfer coefficient (Btu/h.ft^2. F) +A = 1 //Area of base (ft^2) (assumption) +k1 = 26 //Thermal conductivity of steel (Btu/h.ft. F) +k2 = 218 //Thermal conductivity of copper (Btu/h.ft. F) +t = 0.375 //Thickness of steel sheet (in) +h3 = 2500 //Increased steam heat-transfer coefficient (Btu/h.ft^2. F) +h4 = 12 //Increased air heat-transfer coefficient (Btu/h.ft^2. F) + +//Calculation: +R1 = 1/(h1*A) //Steam resistance (h. F/Btu) +R2 = 1/(h2*A) //Air resistance (h. F/Btu) +R3 = (t/12)/(k1*A) //Steel resistance (h. F/Btu) +Rt1 = R1+R2+R3 //Total resistance (with steel) (h. F/Btu) +R4 = (t/12)/(k2*A) //Copper resistance (h. F/Btu) (part 1) +Rt2 = R1+R2+R4 //Total resistance (with copper) (h. F/Btu) +R5 = 1/(h1*A) //New steam resistance (h. F/Btu) +Rt3 = R5+R2+R3 //Total resistance after increasing the steam coefficient (h. F/Btu) +R6 = 1/(h4*A) //Air resistance (h. F/Btu) +Rt4 = R1+R6+R3 //Total resistance after increasing the air coefficient (h. F/Btu) + +//Result: +if (Rt1==Rt2) then + printf("1.The rate of heat transfer is essentially unaffected.") +else + printf("1. The rate of heat transfer is essentially affected.") +end + +if (Rt1==Rt3) then + printf("2. The rate is again unaffected.") +else + printf("2. The rate is again affected.") +end +if (Rt1==Rt4) then + printf("3. The rate is unaffected for this case.") +else + printf("3. The rate is affected for this case.") +end diff --git a/2510/CH19/EX19.2/Ex19_2.sce b/2510/CH19/EX19.2/Ex19_2.sce new file mode 100755 index 000000000..768e8ce71 --- /dev/null +++ b/2510/CH19/EX19.2/Ex19_2.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 19.1: +T1 = 24 //Outside surface temperature ( C) +Ri = 0.0191 //Insulation resistance (K/W) +Q = 1383 //Revised heat transfer rate (Btu/h) + +//Calculation: +T2 = T1-Q*Ri //Temperature at outer surface of insulation ( C) + +//Result: +printf("The temperature at the outer surface of the insulation is : %.1f C .",T2) diff --git a/2510/CH19/EX19.20/Ex19_20.sce b/2510/CH19/EX19.20/Ex19_20.sce new file mode 100755 index 000000000..84af3eef1 --- /dev/null +++ b/2510/CH19/EX19.20/Ex19_20.sce @@ -0,0 +1,19 @@ +//Variable declaration: +rfo = 12/2 //Outside radius of firebrick (ft) +rfi = 5.167 //Inside radius of firebrick (ft) +rso = 6.479 //Outside radius of sil-o-cel (ft) +rsi = 6.063 //Inside radius of fsil-o-cel (ft) +L = 30 //Length of incinerator (ft) +kf = 0.608 //Thermal conductivity of firebrick (Btu/h.ft. F) +ks = 0.035 //Thermal conductivity of sil-o-cel (Btu/h.ft. F) + +//Calculation: +Rf= log(rfo/rfi)/(2*%pi*L*kf) //Resistance of firebrick (h.ft. F/Btu) +Rs= log(rso/rsi)/(2*%pi*L*ks) //Resistance of sil-o-cel (h.ft. F/Btu) +R = Rf+Rs //Total resistance (h.ft. F/Btu) +ro = exp(R*(2*%pi*L*ks))*rso //New outside radius of sil-o-cel (ft) +r= ro-rso //Extra thickness (ft) + +//Result: +printf("The extra thickness is : %.3f ft",r) +printf("Or, the extra thickness is : %.2f in.",r*12) diff --git a/2510/CH19/EX19.3/Ex19_3.sce b/2510/CH19/EX19.3/Ex19_3.sce new file mode 100755 index 000000000..c9b71d9d2 --- /dev/null +++ b/2510/CH19/EX19.3/Ex19_3.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 19.1: +h = 11 //Convective heat transfer coefficient (W/m^2.K) +L = 7.62/10**3 //Insulation thickness (m) +k = 0.04 //Thermal conductivity of wool (W/m.K) + +//Calculation: +Bi = h*L/k //Biot number + +//Result: +printf("The Biot nmuber is : %.1f ",Bi) diff --git a/2510/CH19/EX19.4/Ex19_4.sce b/2510/CH19/EX19.4/Ex19_4.sce new file mode 100755 index 000000000..0fd234072 --- /dev/null +++ b/2510/CH19/EX19.4/Ex19_4.sce @@ -0,0 +1,12 @@ +//Variable declaration: +k = 0.022 //Thermal conductivity of glass wool (Btu/h.ft. F) +T1 = 400 //Inside wall temperature ( F) +T2 = 25 //Outside wall temperature ( C) +L = 3/12 //Length of insulation cover (ft) + +//Calculation: +T_2 = T2*(9/5)+32 //Outside wall temperature in fahrenheit scale ( F) +QbyA = k*(T1-T_2)/L //Heat flux across the wall (Btu/h.ft^2) + +//Result: +printf("The heat flux across the wall is : %.1f Btu/h.ft^2 .",QbyA) diff --git a/2510/CH19/EX19.5/Ex19_5.sce b/2510/CH19/EX19.5/Ex19_5.sce new file mode 100755 index 000000000..01aa172ff --- /dev/null +++ b/2510/CH19/EX19.5/Ex19_5.sce @@ -0,0 +1,30 @@ +//Variable declaration: +w = 8 //Width of wall (m) +H = 3 //Height of wall (m) +h = 21 //Convective heat transfer coefficient between the air and the surface (W/m^2.K) +T1 = -18 //Outside surace of wall temperature ( C) +T3 = 26 //Surrounding air temperature ( C) +l1 = 80/100 //Reduction in cooling load +k = 0.0433 //Thermal conductivity of cork board insulation (W/m.K) +T = 12000 //Units Btu/h in 1 ton of refrigeration + +//Calculation: +A = w*H //Heat transfer area (m^2) (part 1) +Q1 = h*A*(T1-T3) //Rate of heat flow in the absence of insulation (W) +Q2 = Q1*3.4123/T //Rate of heat flow in the absence of insulation (ton of refrigeration) +l2 = 1-l1 //Reduced cooling load (part 2) +Q3 = l2*Q1 //Heat rate with insulation (W) +Rt = (T1-T3)/Q3 //Total thermal resistance ( C/W) +R2 = 1/(h*A) //Convection thermal resistance ( C/W) +R1 = Rt-R2 //Insulation conduction resistance ( C/W) +L = R1*k*A //Required insulation thickness (m) + +//Result: +printf("1. The rate of heat flow through the rectangular wall without insulation is : %.2f kW .",Q1/10**3) +printf("Or, the rate of heat flow through the rectangular wall without insulation in tons of refrigeration is : %.1f ton of refrigeration .",Q2) +if (Q1<0) then + printf("The negative sign indicates heat flow from the surrounding air into the cold room.") +else + printf(" The positive sign indicates heat flow from the surrounding air into the cold room.") +end +printf("2. The required thickness of the insulation board is : %.2f mm .",L*10**3) diff --git a/2510/CH19/EX19.6/Ex19_6.sce b/2510/CH19/EX19.6/Ex19_6.sce new file mode 100755 index 000000000..816774977 --- /dev/null +++ b/2510/CH19/EX19.6/Ex19_6.sce @@ -0,0 +1,17 @@ +//Variable declaration: +//From example 19.5: +Q = -4435.2 //Heat rate with insulation (W) +R2 = 0.00198 //Convection thermal resistance ( C/W) +T3 = 26 //Surrounding air temperature ( C) +h = 21 //Convective heat transfer coefficient between the air and the surface (W/m^2.K) +k = 0.0433 //Thermal conductivity of cork board insulation (W/m.K) +L = 0.00825 //Required insulation thickness (m) + +//Calculation: +T2 = T3+Q*R2 //Interface temperature ( C) (part 1) +Bi = h*L/k //Biot number (part 2) + +//Result: +printf("1. The interface temperature is : %.2f C .",T2) +printf("2. The Biot number is : %.0f ",Bi) +printf("3. Theoretical part.") diff --git a/2510/CH19/EX19.7/Ex19_7.sce b/2510/CH19/EX19.7/Ex19_7.sce new file mode 100755 index 000000000..4cc7b8abd --- /dev/null +++ b/2510/CH19/EX19.7/Ex19_7.sce @@ -0,0 +1,27 @@ +//Variable declaration: +D2 = 0.5/10**3 //External diameter of needle (m) +h3 = 12 //Heat transfer coefficient (W/m^2.K) +L = 1 //Insulation thickness (m) +T1 = 95 //Reactant temperature ( C) +T3 = 20 //Ambient air temperature ( C) +k1 = 16 //Thermal conductivity of needle (W/m.K) +k3 = 0.0242 //Thermal conductivity of air (W/m.K) +D3 = 2/10**3 //Diameter of rubber tube (m) + +//Calculation: +r2 = D2/2 //External radius of needle (m) +r3 = D3/2 //Radius of rubber tube (m) +Rt1 = 1/(h3*(2*%pi*r2*L)) //Thermal resistance ( C/W) +Q1 = (T1-T3)/Rt1 //Rate of heat flow in the absence of insulation (W) +Bi = h3*D2/k1 //Biot number +Nu = h3*D2/k3 //Nusselt number +R2 = log(r3/r2) //Thermal resistance of needle ( C/W) +R3 = 1/(h3*(2*%pi*r3*L)) //Thermal resistance of rubber tube ( C/W) +Rt2 = R2+R3 //Total thermal resistance ( C/W) +Q2 = (T1-T3)/Rt2 //Rate of heat loss (W) + +//Result: +printf("1. The rate of the heat loss from the hypodermic needle with the rubber insulation is : %.2f W .",Q1) +printf(" The rate of the heat loss from the hypodermic needle without the rubber insulation is : %.2f W .",Q2) +printf("2. The Biot number is : %f",Bi) +printf(" The nusselt number is : %.3f ",Nu) diff --git a/2510/CH19/EX19.9/Ex19_9.sce b/2510/CH19/EX19.9/Ex19_9.sce new file mode 100755 index 000000000..f5d3d31bb --- /dev/null +++ b/2510/CH19/EX19.9/Ex19_9.sce @@ -0,0 +1,31 @@ +//Variable declaration: +h = 140 //Convention heat transfer coefficient (W/m^2.K) +D1 = 10/10**3 //Rod diameter (m) +L = 2.5 //Rod length (m) +T1 = 200 //Surface temperature of rod ( C) +T2 = 25 //Fluid temperature ( C) +k = 1.4 //Thermal conductivity of bakellite (W/m.K) +l = 55/10**3 //Insulation thickness (m) + +//Calculation: +Q1 = h*%pi*D1*L*(T1-T2) //Rate of heat transfer for the bare rod (W) (part 1) +Bi = 2 //Critical Biot number (part 2) +D2 = Bi*k/h //Critical diameter associated with the bakelite coating (m) +r2 = D2/2 //Critical radius associated with the bakelite coating (m) +r1 = D1/2 //Rod radius (m) +R1 = log(r2/r1)/(2*%pi*k*L) //Insulation conduction resistance ( C/W) +R2 = 1/(h*(2*%pi*r2*L)) //Convection thermal resistance ( C/W) +Rt1 = R1+R2 //Total thermal resistance ( C/W) +Qc = (T1-T2)/Rt1 //Heat transfer rate at the critical radius (W) +r3 = r1+l //New radius associated with the bakelite coating after insulation (m) (part 3) +R3 = log(r3/r1)/(2*%pi*k*L) //Insulation conduction bakelite resistance ( C/W) +R4 = 1/(h*(2*%pi*r3*L)) //Convection bakelite thermal resistance ( C/W) +Rt2 = R3+R4 //Total bakelite thermal resistance ( C/W) +Q2 = (T1-T2)/Rt2 //Heat transfer rate at the bakelite critical radius (W) +Re = ((Q1-Q2)/Q1)*100 //Percent reduction in heat transfer rate relative to the case of a bare rod (%) + +//Result: +printf("1. The rate of heat transfer for the bare rod is : %0.f W .",Q1) +printf("2. The critical radius associated with the bakelite coating is : %.0f mm.",r2*10**3) +printf(" & the heat transfer rate at the critical radius is : %.0f W .",Qc) +printf("3. The fractional reduction in heat transfer rate relative to the case of a bare rod is : %.1f ",Re) diff --git a/2510/CH21/EX21.1/Ex21_1.sce b/2510/CH21/EX21.1/Ex21_1.sce new file mode 100755 index 000000000..d8d30f789 --- /dev/null +++ b/2510/CH21/EX21.1/Ex21_1.sce @@ -0,0 +1,22 @@ +//Variable declaration: +m = 1 //Mass flowrate (lb) +cP = 1 //Heat capacity (Btu/lb. F) +//From figure 21.3: +T1 = 300 //Temperature of hot fluid leaving exchanger ( F) +T2 = 540 //Temperature of hot fluid entering exchanger ( F) +T3 = 60 //Temperature of cold fluid leaving exchanger ( F) +T4 = 300 //Temperature of cold fluid entering exchanger ( F) + +//Calculation: +DSh = m*cP*log((T1+460)/(T2+460)) //Entropy for hot fluid (Btu/ F) +DSc = m*cP*log((T4+460)/(T3+460)) //Entropy for cold fluid (Btu/ F) +DSa = DSh+DSc //Entropy for one exchanger (Btu/ F) +DSt = DSa*2 //Total entropy change (Btu/ F) + +//Result: +printf("The entropy chage is : %.4f Btu/ F .",DSt) +if (DSt>0) then + printf("There is a positive entropy change.") +else + printf("There is a negative entropy change.") +end diff --git a/2510/CH21/EX21.2/Ex21_2.sce b/2510/CH21/EX21.2/Ex21_2.sce new file mode 100755 index 000000000..f5b06ae38 --- /dev/null +++ b/2510/CH21/EX21.2/Ex21_2.sce @@ -0,0 +1,16 @@ +//Variable declaration: +//From example 21.1: +DSh = -0.2744 //Entropy for hot fluid (Btu/ F) +DSc = 0.3795 //Entropy for cold fluid (Btu/ F) +m = 1 //Mass flowrate (lb) +cP = 1 //Heat capacity (Btu/lb. F) +//From figure 21.4: +DT = 0 //Temperature difference driving force ( F) +DS_D = 0 //Entropy for D exchanger (Btu/ F) + +//Calculation: +DS_C = DSh+DSc //Entropy for C exchanger (Btu/ F) +DSt = DS_C+DS_D //Total entropy change of exchangers (Btu/ F) + +//Result: +printf("The total entropy change is : %f Btu/ F .",DSt) diff --git a/2510/CH21/EX21.3/Ex21_3.sce b/2510/CH21/EX21.3/Ex21_3.sce new file mode 100755 index 000000000..a340e8add --- /dev/null +++ b/2510/CH21/EX21.3/Ex21_3.sce @@ -0,0 +1,16 @@ +//Variable declaration: +//From figure 21.5: +m = 2 //Mass flowrate (lb) +cP = 1 //Heat capacity (Btu/lb. F) +DS1 = -0.2744 //Entropy for hot fluid for E exchanger (Btu/ F) +T1 = 180 //Temperature cold fluid entering the E exchabger ( F) +T2 = 60 //Temperature cold fluid leaving the E exchabger ( F) + +//Calculation: +DS2 = m*cP*log((T1+460)/(T2+460)) //Entropy for cold fluid for E exchanger (Btu/ F) +DS_E = DS1+DS2 //Entropy for E exchanger (Btu/ F) +DS_F = DS_E //Entropy for F exchanger (Btu/ F) +DSt = DS_F+DS_E //Entropy change in exchangers E and F (Btu/ F) + +//Result: +printf("The entropy change in exchangers E and F is : %.4f Btu/ F",DSt) diff --git a/2510/CH22/EX22.10/Ex22_10.sce b/2510/CH22/EX22.10/Ex22_10.sce new file mode 100755 index 000000000..2cea58d8a --- /dev/null +++ b/2510/CH22/EX22.10/Ex22_10.sce @@ -0,0 +1,25 @@ +//Variable declaration: +//From example 22.9: +t1 = 23.5 //Initial temperature of oil ( C) +t2 = 27 //Final temperature of oil ( C) +T1 = 93 //Water heating temperature of water ( C) +T2 = 88.16 //Minimum temperature of heating water ( C) +U = 34.6 //Overall heat transfer coefficient (W/m^2. C) +Q = 7227.2 //Duty of exchanger (W) +D = 6*0.0254 //Inside diameter of %pipe (m) +l = 6.68 //Previous heat transfer length (m) + +//Calculation: +DT1 = T1-t1 //Inlet temperature difference ( C) +DT2 = T2-t2 //Outlet temperature difference ( C) +DTlm = (DT1-DT2)/log(DT1/DT2) //Log mean temperature difference ( C) +A = Q/(U*DTlm) //Required heat transfer area (m^2) +L = A/(%pi*D) //Required heat transfer length (m) + +//Result: +printf("The length of the parallel %%pipe heat exchanger is : %.2f ",L) +if L>l then + printf("The tube length would increase slightly.") +elseif L<l then + printf("The tube length would decrease slightly.") +end diff --git a/2510/CH22/EX22.12/Ex22_12.sce b/2510/CH22/EX22.12/Ex22_12.sce new file mode 100755 index 000000000..30538292d --- /dev/null +++ b/2510/CH22/EX22.12/Ex22_12.sce @@ -0,0 +1,22 @@ +//Variable declaration: +T = 80 //Pipe surface temperature ( F) +t1 = 10 //Inlet temperature of brine solution ( F) +m = 1200 //mass flowrate of solution (kg/s) +c = 0.99 //Heat capacity of brine solution (Btu/lb. F) +A = 2.5 //Heat transfer area (ft^2) +U1 = 150 //Overall heat transfer coefficient at temperature approach (Btu/h.ft^2. F) +U2 = 140 //Overall heat transfer coefficient at inlet brine temperature (Btu/h.ft^2. F) + +//Calculation: +DT1 = T-t1 //Temperature approach at the pipe entrance ( F) + +function [ans] = equation(DT2) + Q1 = m*c*(DT1-DT2) //Energy balance to the brine solution across the full length of the pipe (Btu/h) + DTlm = (DT1-DT2)*log(DT2/DT1) //Log mean temperature difference ( F) + Q2 = A*(U2*DT1-U1*DT2)/log((U2*DT1)/(U1*DT2)) //Heat transfer rate (Btu/h) + ans = Q2-Q1 +endfunction +t2 = T-fsolve(1,equation) //The temperature of the brine solution ( F) + +//Results: +printf("The temperature of brine solution is: %.0f C",(t2-32)/1.8) diff --git a/2510/CH22/EX22.13/Ex22_13.sce b/2510/CH22/EX22.13/Ex22_13.sce new file mode 100755 index 000000000..dec3f79be --- /dev/null +++ b/2510/CH22/EX22.13/Ex22_13.sce @@ -0,0 +1,16 @@ +//Variable declaration: +m = 1200 //mass flowrate of solution (kg/s) +c = 0.99 //Heat capacity of brine solution (Btu/lb. F) +DT1 = 70 //Temperature approach at the pipe entrance ( F) +DT2 = 51.6 //Temperature difference at the pipe exit ( F) + +//Calculation: +Q = m*c*(DT1-DT2) //Heat transfer rate (Btu/h) +DTlm = (DT1-DT2)/log(DT1/DT2) //Log mean temperature difference ( F) +Q1 = round(Q*10**-1)/10**-1 + +//Result: +printf("1. The rate of heat transfer is : %f Btu/h.",Q1) +printf("Or, the rate of heat transfer is : %.0f W.",Q/3.412) +printf("2. The log mean temperature difference is : %.1f F.",DTlm) +printf("Or, the log mean temperature difference is : %.1f C.",DTlm/1.8) diff --git a/2510/CH22/EX22.23/Ex22_23.sce b/2510/CH22/EX22.23/Ex22_23.sce new file mode 100755 index 000000000..a9416287d --- /dev/null +++ b/2510/CH22/EX22.23/Ex22_23.sce @@ -0,0 +1,23 @@ +//Variable declaration: +Too = 100 //Steam temperature ( C) +Ti = 18 //Initial temperature of liquid TCA ( C) +Tf = 74 //Final temperature of liquid TCA ( C) +t = 180 //Heating time (s) +p = 87.4 //Density of TCA (lb/ft^3) +V = 18 //Kinematic viscosity of TCA (m^2/s) +cp = 0.23 //Heat capacity of TCA (Btu/lb. F) +U = 200 //Overall heat transfer coefficient (Btu/h.ft^2. F) + +//Calculation: +ui = Too-Ti //Initial excess temperature ( C) +uf = Too-Tf //Final excess temperature ( C) +R = log(ui/uf) //Ratio t/r +r = t/R //Thermal time constant (s) +A = p*V*cp/(3600*U*r) //Required heating area (ft^3) +Ti_F = Ti*9/5+32 //Initial temperature in fahrenheit scale ( F) +Tf_F = Tf*9/5+32 //Final temperature in fahrenheit scale ( F) +Q = p*V*cp*(Tf_F-Ti_F) //Total amount of heat added (Btu) + +//Result: +printf("1. The required surface area of the heating coil is : %e ft^3",A) +printf("2. The total heat added to the liquid TCA is : %.0f Btu",Q) diff --git a/2510/CH22/EX22.24/Ex22_24.sce b/2510/CH22/EX22.24/Ex22_24.sce new file mode 100755 index 000000000..365c0072e --- /dev/null +++ b/2510/CH22/EX22.24/Ex22_24.sce @@ -0,0 +1,46 @@ +//Variable declaration: +m1 = 62000 //Mass flowrate of alcohol (lb/h) +h1 = 365 //Enthalpy of vapour (Btu/lb) +cp = 1 //Heat capacity of water (Btu/lb. F) +T1 = 85 //Entering temperature of water ( F) +T2 = 120 //Exit temperature of water ( F) +a1 = 2.11 //Flow area for the shell side (ft^2) +N = 700 //Total number of tubes +a2 = 0.546 //Flow area per tube (in^2/tube) +n = 4 //Number of tube passes +p = 62.5 //Density of water (lb/ft^3) +L = 16 //Length of condenser (ft) +hio = 862.4 //Cooling water inside film coefficient (Btu/h.ft^2. F) +g = 9.8 //Gravitational accleration (m^2/s) +Rf = 0.003 //Fouling factor (Btu/h.ft^2. F) + +//Calculation: +Q1 = m1*h1 //Heat loss from alcohol (Btu/h) +Q2 = Q1 //Heat gained by water (Btu/h) +DT = T2-T1 //Temperature difference ( F) +m2 = Q2/(cp*DT) //Water mass flow rate (lb/h) +LMTD = ((T2-32)-(T1-32))/log((T2-32)/(T1-32)) //Log mean temperature difference ( F) +at = (N*a2)/(144*n) //Total flow area for tube side (ft^2) +G1 = m1/a1 //Mass velocity of flow in shell side (lb/h.ft^2) +G2 = m2/at //Mass velocity of flow in tube side (lb/h.ft^2) +V = G2/(3600*p) //Velocity of water (ft/s) +G3 = m1/(L*N)**(2/3) //Loading G (lb/h.ft) +//For alcohol: +kf = 0.105 //Thermal conductivity (Btu/h.ft. F) +muf = 0.55*2.42 //Dynamic viscosity (lb/ft.h) +sf = 0.79 // +pf = sf*p //Density (lb/ft^3) +h = 151*(((kf**3)*(pf**2)*g*muf)/((muf**2)*n*G3))**(1/3) //Heat transfer coefficient for the shell side (Btu/h.ft^2. F) +ho = h //Outside heat transfer coefficient of the tube bundle (Btu/h.ft^2. F) +Uc = (hio*ho)/(hio+ho) //Overall heat transfer coefficient for a new (clean) heat exchanger (Btu/h.ft^2. F) +A = N*L*0.2618 //Area for heat transfer (ft^2) +Ud = Q1/(A*DT) //Design (D) overall heat transfer coefficient (Btu/h.ft^2. F) +Rd = (Uc-Ud)/(Uc*Ud) //Dirt (d) factor (Btu/h.ft^2. F) + +//Result: +printf("The dirt (d) factor is : %.4f Btu/h.ft^2. F .",Rd) +if (Rd>Rd) then + printf("Therefore, the exchanger as specified is unsuitable for these process conditions since the fouling factor is above the recommended value. Cleaning is recommended.") +else + printf("Therefore, the exchanger as specified is suitable for these process conditions since the fouling factor is below the recommended value. Cleaning is not recommended.") +end diff --git a/2510/CH22/EX22.6/Ex22_6.sce b/2510/CH22/EX22.6/Ex22_6.sce new file mode 100755 index 000000000..892d35303 --- /dev/null +++ b/2510/CH22/EX22.6/Ex22_6.sce @@ -0,0 +1,20 @@ + //Variable declaration: +//From steam tables: +h1 = 1572 //Enthalpy for super heated steam at (P = 40 atm, T = 1000 F) (Btu/lb) +h2 = 1316 //Enthalpy for super heated steam at (P = 20 atm, T = 600 F) (Btu/lb) +h3 = 1151 //Enthalpy for saturated steam (Btu/lb) +h4 = 28.1 //Enthalpy for saturated water (Btu/lb) +m1 = 1000 //Mass flowrate of steam (lb/h) +syms m //Mass flow rate of steam (lb/h) + +//Calculation: +Dh1 = m1*(h3-h4) //The change in enthalpy for the vaporization of the water stream (Btu/h) +Dh2 = m*(h1-h2) //The change in enthalpy for the cooling of the water stream (Btu/h) +x = eval(solve(Dh1-Dh2,m)) //Mass flowrate of steam (lb/h) +m2 = x; //Mass flowrate of steam (lb/h) + +//Result: +disp("The mass flowrate of the utility steam required is : ") +disp(m2) +disp(" lb/h.") + diff --git a/2510/CH22/EX22.7/Ex22_7.sce b/2510/CH22/EX22.7/Ex22_7.sce new file mode 100755 index 000000000..ca5c03fc0 --- /dev/null +++ b/2510/CH22/EX22.7/Ex22_7.sce @@ -0,0 +1,23 @@ +//Variable declaration: +//From table 22.1: +QH1 = 12*10**6 //Heat duty for process unit 1 (Btu/h) +QH2 = 6*10**6 //Heat duty for process unit 2 (Btu/h) +QH3 = 23.5*10**6 //Heat duty for process unit 3 (Btu/h) +QH4 = 17*10**6 //Heat duty for process unit 4 (Btu/h) +QH5 = 31*10**6 //Heat duty for process unit 5 (Btu/h) +T1 = 90 //Supply water temperature ( F) +T2 = 115 //Return water temperature ( F) +cP = 1 //Cooling water heat capacity (Btu/(lb. F)) +p = 62*0.1337 //Density of water (lb/gal) +BDR = 5/100 //Blow-down rate + +//Calculation: +QHL = (QH1+QH2+QH3+QH4+QH5)/60 //Heat load (Btu/min) +DT = T2-T1 //Change in temperature ( F) +qCW = round(QHL*10**-5)/10**-5/(DT*cP*p) //Required cooling water flowrate (gpm) +qBD = BDR*qCW //Blow-down flow (gpm) +qCW = round(qCW*10**-1)/10**-1 + +//Result: +printf("The total flowrate of cooling water required for the services is : %f gpm.",qCW) +printf("The required blow-down flow is : %.0f gpm.",qBD) diff --git a/2510/CH22/EX22.8/Ex22_8.sce b/2510/CH22/EX22.8/Ex22_8.sce new file mode 100755 index 000000000..59da2015f --- /dev/null +++ b/2510/CH22/EX22.8/Ex22_8.sce @@ -0,0 +1,17 @@ +//Variable declaration: +Q1 = 10*10**6 //Unit heat duty for process unit 1 (Btu/h) +Q2 = 8*10**6 //Unit heat duty for process unit 2 (Btu/h) +Q3 = 12*10**6 //Unit heat duty for process unit 3 (Btu/h) +Q4 = 20*10**6 //Unit heat duty for process unit 4 (Btu/h) +hv = 751 //Enthalpy of vaporization for pressure 500 psig (Btu/lb) + +//Calculation: +mB1 = Q1/hv //Mass flowrate of 500 psig steam through unit 1 (lb/h) +mB2 = Q2/hv //Mass flowrate of 500 psig steam through unit 2 (lb/h) +mB3 = Q3/hv //Mass flowrate of 500 psig steam through unit 3 (lb/h) +mB4 = Q4/hv //Mass flowrate of 500 psig steam through unit 4 (lb/h) +mBT = mB1+mB2+mB3+mB4 //Total steam required (lb/h) +mBT = round(mBT*10**-1)/10**-1 + +//Result: +printf("The total steam required is : %f lb/h.",mBT) diff --git a/2510/CH22/EX22.9/Ex22_9.sce b/2510/CH22/EX22.9/Ex22_9.sce new file mode 100755 index 000000000..13a64b8e8 --- /dev/null +++ b/2510/CH22/EX22.9/Ex22_9.sce @@ -0,0 +1,71 @@ +//Variable declaration: +po = 53*16.0185 //Density of oil (kg/m^3) +co = 0.46*4186.7 //Heat capacity of oil (J/kg. C) +pi = %pi +muo = 150/1000 //Dynamic viscosity of oil (kg/m.s) +ko = 0.11*1.7303 //Thermal conductivity of oil (W/m. C) +qo = 28830*4.381*10**-8 //Volumetric flowrate of oil (m^3/s) +pw = 964 //Density of water (kg/m^3) +cw = 4204 //Heat capacity of water (J/kg. C) +muw = 0.7/3600*1.4881 //Dynamic viscosity of water (kg/m.s) +kw = 0.678 //Thermal conductivity of water (W/m. C) +qw = 8406*4.381*10**-8 //Volumetric flowrate of water (m^3/s) +t1 = 23.5 //Initial temperature of oil ( C) +t2 = 27 //Final temperature of oil ( C) +T1 = 93 //Water heating temperature of water ( C) +syms T2 //Minimum temperature of heating water ( C) +syms A //Heat transfer area (m^2) +Uc = 35.4 //Clean heat transfer coefficient (W/m^2.K) +Rf = 0.0007 //Thermal resistance (m^2.K/W) +D = 6*0.0254 //Inside diameter of pipe (m) + +//Calculation: +vo = muo/po //Kinematic viscosity of oil (m^2/s) +mo = po*qo //Mass flowrate of oil (kg/s) +vw = muw/pw //Kinematic viscosity of (m^2/s) +mw = pw*qw //Masss flow rate of water (kg/s) +Q1 = mo*co*(t2-t1) //Duty of exchanger of oil (W) +T2m = t1 //Lowest possible temperature of the water ( C) (part 1) +Qmw = mw*cw*(T1-T2m) //Maximum duty of exchanger of water (W) (part 2) +Q2 = mw*cw*(T1-T2) //Duty of exchanger of water in terms of T2 (W) +x = eval(solve(Q1-Q2,T2)) //Solving value for T2 ( C) +T3 = x; //Minimum temperature of heating water ( C) +DT1 = T3-t1 //Inlet temperature difference ( C) +DT2 = T1-t2 //Outlet temperature difference ( C) +DTlm = (DT1-DT2)/log(DT1/DT2) //Log mean temperature difference ( C) +Ud1 = 1/Uc+Rf //Dirty heat transfer coefficient (W/m^2.K) (part 3) +Ud2 = 34.6 //Dirty heat transfer coefficient (W/m^2. C) +Q3 = Ud2*A*DTlm //Duty of exchanger (W) (part 4) +y = eval(solve(Q1-Q3,A)) //Heat transfer area (m^2) +A1 = y //Required heat transfer area (m^2) +L = A1/(pi*D) //Required heat transfer length (m) +Qmo = mo*co*(T1-t1) //Maximum duty of exchanger of oil (W) (part 5) +Qm = Qmw //Maximum duty of exchanger (W) +E = Q1/Qm*100 //Effectiveness (%) +NTU = Ud2*A1/(mw*cw) //Number of transfer units + +//Result: +disp("1. The lowest possible temperature of the water is :") +disp(T2m) +disp(" C .") + +disp("2. The log mean temperature difference is : ") +disp (DTlm) +disp(" C .") + +disp("3. The overall heat transfer coefficient for the new clean exchanger is : ") +disp (Ud2) +disp ("W/m^2. C .") + +disp("4. The length of the double pipe heat exchanger is : ") +disp(L) +disp (" m .") + +disp("5. The effectiveness of the exchanger is : ") +disp(E) +disp("%") + +disp("The NTU of the exchanger is : ") +disp(NTU) + +// Answers are correct. Please calculate manually. diff --git a/2510/CH23/EX23.6/Ex23_6.sce b/2510/CH23/EX23.6/Ex23_6.sce new file mode 100755 index 000000000..4c50544f7 --- /dev/null +++ b/2510/CH23/EX23.6/Ex23_6.sce @@ -0,0 +1,11 @@ +//Variable declaration: +Q = 20000 //Fuel input (Btu) +e = 1 //Energy produced (kW.h) +Btu = 3412 //Units Btu in 1 kW.h + +//Calulation: +ER = Q/Btu //Energy requirement in 1990 (kW.h) +E = e/ER*100 //Efficiency of energy conversion (%) + +//Result: +printf("The efficiency of energy conversion is : %.1f %%",E) diff --git a/2510/CH23/EX23.7/Ex23_7.sce b/2510/CH23/EX23.7/Ex23_7.sce new file mode 100755 index 000000000..cf3dec1b3 --- /dev/null +++ b/2510/CH23/EX23.7/Ex23_7.sce @@ -0,0 +1,12 @@ +//Variable declaration: +ADL1 = 2 //Average daily load (MW) +R = 25/100 //Reduction in electrical load (%) + +//Calculation: +L = 1-R //New load fraction +ADL2 = ADL1*L //New average daily load (MW) +AR = ADL1-ADL2 //Average reduction in electrical load (MW) + +//Result: +printf("The new Average daily load for the plant is : %f MW.",ADL2) +printf("The average reduction in electrical load is : %f MW.",AR) diff --git a/2510/CH24/EX24.10/Ex24_10.sce b/2510/CH24/EX24.10/Ex24_10.sce new file mode 100755 index 000000000..256e98437 --- /dev/null +++ b/2510/CH24/EX24.10/Ex24_10.sce @@ -0,0 +1,26 @@ +//variable Declaration: +mTa = [100,100,100,100,100,100,100,100,100,100] //Mean weeks for thermometer failure(A) +mTb = [90,90,90,90,90,90,90,90,90,90] //Mean weeks for thermometer failure(B) +mTc = [80,80,80,80,80,80,80,80,80,80] //Mean weeks for thermometer failure(C) +sTa = 30 //Standard deviation (weeks) for thermometer failure(A) +sTb = 20 //Standard deviation (weeks) for thermometer failure(B) +sTc = 10 //Standard deviation (weeks) for thermometer failure(C) +Ra = [0.52,0.80,0.45,0.68,0.59,0.01,0.50,0.29,0.34,0.46] //Random No corrosponding to A +Rb = [0.77,0.54,0.96,0.02,0.73,0.67,0.31,0.34,0.00,0.48] //Random No corrosponding to B +Rc = [0.14,0.39,0.06,0.86,0.87,0.90,0.28,0.51,0.56,0.82] //Random No corrosponding to B +Za = [0.05,0.84,-0.13,0.47,0.23,-2.33,0.00,-0.55,-0.41,-0.10] //Normal variable corrosponding to random No for A +Zb = [0.74,0.10,1.75,-2.05,0.61,0.44,-0.50,-0.41,-3.90,-0.05] //Normal variable corrosponding to random No for B +Zc = [-1.08,-0.28,-1.56,1.08,1.13,1.28,-0.58,0.03,0.15,0.92] //Normal variable corrosponding to random No for C + +//Calculations: +Ta = mTa+sTa*Za +Tb = mTb+sTb*Zb +Tc = mTc+sTc*Zc +Ts = min(list(Ta,Tb)) +Ts = min(list(Ts,Tc)) +k = sum(Ts)/length(Ts) +m = [k,k,k,k,k,k,k,k,k,k] +s = sqrt(sum((Ts-m)**2)/(length(Ts)-1)) + +//Results: +printf("Standard deviation : %.1f Weeks",s) diff --git a/2510/CH24/EX24.15/Ex24_15.sce b/2510/CH24/EX24.15/Ex24_15.sce new file mode 100755 index 000000000..760db22c0 --- /dev/null +++ b/2510/CH24/EX24.15/Ex24_15.sce @@ -0,0 +1,13 @@ +//Variable declaration: +t = 273 //Standard temperature (K) +v = 0.0224 //Volume of air occupied by 1 gmol of ideal gas (m^3) +V = 1100 //Volume of heat exchanger (m^3) +T = 22+273 //Temperature of heat exchanger (K) +x1 = 0.75 //gmols of hydrocarbon leaking from the exchanger (gmol) + +//Calculation: +n = V*(1/v)*(t/T) //Total number of gmols of air in the room (gmol) +xHC = (x1/(n+x1))*10**6 //The mole fraction of hydrocarbon in the room (ppm) +ans = round((xHC*1000)*10**-1)/10**-1 +//Result: +printf("1. The mole fraction of hydrocarbon in the room is : %f ppb .",ans) diff --git a/2510/CH24/EX24.4/Ex24_4.sce b/2510/CH24/EX24.4/Ex24_4.sce new file mode 100755 index 000000000..eb49afda8 --- /dev/null +++ b/2510/CH24/EX24.4/Ex24_4.sce @@ -0,0 +1,19 @@ +//Variable declaration: +fm = 30/100 //Mole fraction of methane +fe = 50/100 //Mole fraction of ethane +fp = 20/100 //Mole fraction of pentane +LFLm = 0.046 //Lower flammability limit for methane +LFLe = 0.035 //Lower flammability limit for ethane +LFLp = 0.014 //Lower flammability limit for propane +UFLm = 0.142 //Upper flammability limit for methane +UFLe = 0.151 //Upper flammability limit for ethane +UFLp = 0.078 //Upper flammability limit for propane + +//Calculation: +LFLmix = 1/((fm/LFLm)+(fe/LFLe)+(fp/LFLp)) //Lower flammability limit of gas mixture +UFLmix = 1/((fm/UFLm)+(fe/UFLe)+(fp/UFLp)) //Upper flammability limit of gas mixture + +//Result: +printf("The upper flammability limit (UFL) of the gas mixture is : %.2f %%",UFLmix*100) +printf("The lower flammability limit (LFL) of the gas mixture is : %.2f %%",LFLmix*100) +printf("There is a printing mistake in book.") diff --git a/2510/CH24/EX24.5/Ex24_5.sce b/2510/CH24/EX24.5/Ex24_5.sce new file mode 100755 index 000000000..db07b5bae --- /dev/null +++ b/2510/CH24/EX24.5/Ex24_5.sce @@ -0,0 +1,13 @@ +//Variable declaration: +P_A = 10/100 //Probability that the first tube is defective if the first is replaced +P_B = 10/100 //Probability that the second tube is defective if the first is replaced + +//Calculation: +P_AB = P_A*P_B //Probability that the two tubes are defective if the first is replaced +P_B_A = 9/99 //Probability that the second tube is defective if the first tube is not replaced +Pd_AB = P_A*P_B_A //Probability that both tubes are defective if the first tube is not replaced + +//Result: +printf("The probability that both tubes are defective if :") +printf("(a) the first is replaced before the second is drawn is : %f",P_AB) +printf("(b) the first is not replaced before the second is drawn is : %f",Pd_AB) diff --git a/2510/CH24/EX24.6/Ex24_6.sce b/2510/CH24/EX24.6/Ex24_6.sce new file mode 100755 index 000000000..989079e1a --- /dev/null +++ b/2510/CH24/EX24.6/Ex24_6.sce @@ -0,0 +1,9 @@ +//Variable declaration: +syms X //Range of X +Px = 1.7*(exp(-1.7*X)) //Probability distribution function + +//Calculation: +P = eval(integrate(Px, X,2,6)) //Probability that X will have a value between 2 and 6 + +//Result: +printf("The probability that X will have a value between 2 and 6 is : %.4f",P) diff --git a/2510/CH24/EX24.7/Ex24_7.sce b/2510/CH24/EX24.7/Ex24_7.sce new file mode 100755 index 000000000..b69899f04 --- /dev/null +++ b/2510/CH24/EX24.7/Ex24_7.sce @@ -0,0 +1,16 @@ +//Variable Declaration: +n = 20 //Total number of components +p = 0.1 //Probability of success + +//Calculations: +function [ans]= binomial(n,p,x) + P=0 + for x = 0:x-1 + P = P + p**x*(1-p)**(n-x)*factorial(n)/(factorial(x)*factorial(n-x)) + end + disp(P); + ans = P +endfunction + +//Results: +printf("Probability that the sprinkler system fails : %.2f %%",(1-binomial(n,p,4))*100) diff --git a/2510/CH24/EX24.8/Ex24_8.sce b/2510/CH24/EX24.8/Ex24_8.sce new file mode 100755 index 000000000..70492c7e1 --- /dev/null +++ b/2510/CH24/EX24.8/Ex24_8.sce @@ -0,0 +1,9 @@ +//Variable declaration: +a = 1.3*10^-3 //Constant a +B = 0.77 //Constant B +syms t //Time (h) +Ft = a*B*t^(B-1)*(exp(-a*t^B)) //Pdf for heat exchanger tube +Pt = eval(integrate(Ft, "t",0,1000)) //Probability that a heat exchanger will fail within 100 hours + +//Result: +printf("The probability that a tube in a heat exchanger will fail in 1000 hours is : %.2f",Pt) diff --git a/2510/CH24/EX24.9/Ex24_9.sce b/2510/CH24/EX24.9/Ex24_9.sce new file mode 100755 index 000000000..c5ecabac5 --- /dev/null +++ b/2510/CH24/EX24.9/Ex24_9.sce @@ -0,0 +1,13 @@ +//Variable declaration: +m = 0.4008 //Mean(inch) +s = 0.0004 //Standard Deviation(inch) +UL = 0.4000+0.001 //Upper Limit +LL = 0.4000-0.001 //Upper Limit + +//Calculation: +Ps = cdfnor("PQ",UL,m,s)-cdfnor("PQ",LL,m,s)//Probability of meeting specs +Pd = 1-Ps //Probability of defect + +//Results: +printf("Probability of meeting specifications: %.2f %%",Ps*100) +printf("Probability of Defect: %.2f %%",Pd*100) diff --git a/2510/CH26/EX26.11/Ex26_11.sce b/2510/CH26/EX26.11/Ex26_11.sce new file mode 100755 index 000000000..01209cd9e --- /dev/null +++ b/2510/CH26/EX26.11/Ex26_11.sce @@ -0,0 +1,14 @@ +//Key: +//f(x) : Objective Function +//ci(x)'s : Constraints + +//Variable Declaration: +function [a] = f(x) + a = -2.0*x(1) - 1.6*x(2) +endfunction + +//Calculation +X = [16820,1152] + +//Result: +printf("Maximum Profit is $ %.0f /day or $ %f /year",-f(X),-365*f(X)) diff --git a/2510/CH26/EX26.8/Ex26_8.sce b/2510/CH26/EX26.8/Ex26_8.sce new file mode 100755 index 000000000..52998dda4 --- /dev/null +++ b/2510/CH26/EX26.8/Ex26_8.sce @@ -0,0 +1,16 @@ +//Variable Declaration: +syms A +syms B +syms r +syms C + +//Calculation: +res = solve([A + B*log(2)-log(3),A + B*log(4)-log(12)],[A,B]) +A = -0.2877 +B = round(float(res[B])) +kA = round(exp(A),2) +a = B + +//Result: +disp("The equation for rate of reaction is: %f kA*C**a ") +disp(-r) diff --git a/2510/CH26/EX26.9/Ex26_9.sce b/2510/CH26/EX26.9/Ex26_9.sce new file mode 100755 index 000000000..853a3b1ff --- /dev/null +++ b/2510/CH26/EX26.9/Ex26_9.sce @@ -0,0 +1,10 @@ +//Variable Declaration: +T = [-40,-20,0,10,12,30,40,50,60,80,100,150,200,250,300,400,500] +u = [1.51,1.61,1.71,1.76,1.81,1.86,1.90,1.95,2.00,2.09,2.17,2.38,2.57,2.75,2.93,3.25,3.55] + +//Calculations: +[B,A] = reglin(T,u) + +//Results: +printf("The value of A in regression model is: %.4f",A) +printf("The value of B in regression model is: %.4f",B) diff --git a/2510/CH27/EX27.10/Ex27_10.sce b/2510/CH27/EX27.10/Ex27_10.sce new file mode 100755 index 000000000..620dec6ac --- /dev/null +++ b/2510/CH27/EX27.10/Ex27_10.sce @@ -0,0 +1,70 @@ +//Variable declaration: +f = 100000 //Flow rate of flue gas (acfm) +i = 0.1 //Interest rate +//From table 27.4: +//For finned preheater: +ac1 = 3.1 //Equipment cost ($/acfm) +ac2 = 0.8 //Installation cost ($/acfm) +ac3 = 0.06 //Operating cost ($/acfm-yr) +ac4 = 14000 //Maintenance cost ($/yr) +an = 20 //Lifetime (yr) +//For 4-pass preheater: +bc1 = 1.9 //Equipment cost ($/acfm) +bc2 = 1.4 //Installation cost ($/acfm) +bc3 = 0.06 //Operating cost for ($/acfm-yr) +bc4 = 28000 //Maintenance cost ($/yr) +bn = 15 //Lifetime of (yr) +//For 2-pass preheater: +cc1 = 2.5 //Equipment cost ($/acfm) +cc2 = 1.0 //Installation cost ($/acfm) +cc3 = 0.095 //Operating cost for ($/acfm-yr) +cc4 = 9500 //Maintenance cost for ($/yr) +cn = 20 //Lifetime of (yr) + +//Calculation: +//For Finned preheater: +aEC = f*ac1 //Total equipment cost ($) +aIC = f*ac2 //Total installation cost ($) +aOC = f*ac3 //Total operating cost ($) +aMC = f*ac4 //Total maintenance cost ($) +aCRF = (i*(1+i)**an)/((1+i)**an-1) //Capital recovery factor +aAEC = aEC*aCRF //Equipment annual cost ($/yr) +aAIC = aIC*aCRF //Installation annual cost($/yr) +aAOC = ac3*f //Annual operating cost ($) +aAMC = ac4 //Annual maintenance cost ($) +aTAC = aAEC+aAIC+aAOC+aAMC //Total annual cost ($) + +//For 4-pass preheater: +bEC = f*bc1 //Total equipment cost ($) +bIC = f*bc2 //Total installation cost ($) +bOC = f*bc3 //Total operating cost ($) +bMC = f*bc4 //Total maintenance cost ($) +bCRF = (i*(1+i)**bn)/((1+i)**bn-1) //Capital recovery factor +bAEC = bEC*bCRF //Equipment annual cost ($/yr) +bAIC = bIC*bCRF //Installation annual cost($/yr) +bAOC = bc3*f //Annual operating cost ($) +bAMC = bc4 //Annual maintenance cost ($) +bTAC = bAEC+bAIC+bAOC+bAMC //Total annual cost ($) +//For 2-pass preheater: +cEC = f*cc1 //Total equipment cost ($) +cIC = f*cc2 //Total installation cost ($) +cOC = f*cc3 //Total operating cost ($) +cMC = f*cc4 //Total maintenance cost ($) +cCRF = (i*(1+i)**cn)/((1+i)**cn-1) //Capital recovery factor +cAEC = cEC*cCRF //Equipment annual cost ($/yr) +cAIC = cIC*cCRF //Installation annual cost($/yr) +cAOC = cc3*f //Annual operating cost ($) +cAMC = cc4 //Annual maintenance cost ($) +cTAC = cAEC+cAIC+cAOC+cAMC //Total annual cost ($) + +//Result: +printf("Total annual cost for finned preheater is : $ %.0f",aTAC) +printf("Total annual cost for 4-pass preheater is : $ %.0f",bTAC) +printf("Total annual cost for 2-pass preheater is : $ %.0f",cTAC) +if (cTAC<aTAC & cTAC<bTAC) then + printf("According to the analysis, the 2-pass exchanger is the most economically attractive device since the annual cost is the lowest.") +elseif (bTAC<aTAC & bTAC<cTAC) then + printf("According to the analysis, the 4-pass exchanger is the most economically attractive device since the annual cost is the lowest.") +elseif (aTAC<cTAC & aTAC<bTAC) then + printf("According to the analysis, the finned exchanger is the most economically attractive device since the annual cost is the lowest.") +end diff --git a/2510/CH27/EX27.12/Ex27_12.sce b/2510/CH27/EX27.12/Ex27_12.sce new file mode 100755 index 000000000..fbd3ef295 --- /dev/null +++ b/2510/CH27/EX27.12/Ex27_12.sce @@ -0,0 +1,24 @@ +//Variable declaration: +TH = 500 //Hot stream temperature at exchanger 1 ( F) +tc = 100 //Cold stream temperature at exchanger 2 ( F) +A = 10 //Constant A +B1 = 100000 //Constant B1 +B2 = 4000 //Constant B2 +B3 = 400000 //Constant B3 + +//Calculations: +//It forms equation fo form t^2 - t(Th-tc) +tcTH +B/A +t1 = roots([1, -(TH+tc),(tc*TH + B1/A) ]); //Roots +tmax1 = TH - sqrt(B1/A) //Upon maximising profit +t2 = roots([1, -(TH+tc),(tc*TH + B2/A) ]); //Roots +tmax2 = TH - sqrt(B2/A) //Upon maximising profit +t3 = roots([1, -(TH+tc),(tc*TH + B3/A) ]); //Roots +tmax3 = TH - sqrt(B3/A) //Upon maximising profit + +//Results: +printf("tBE for case 1: %.0f F %.0f F",t1(1),t1(2)) +printf("tmax1: %.0f F",tmax1) +printf("tBE for case 2: %.0f F %.0f F",t2(1),t2(2)) +printf("tmax1: %.0f F",tmax2) +printf("tBE for case 1: %.0f F %.0f F",t3(1),t3(2)) +printf("tmax1 : %.0f F",tmax3) diff --git a/2510/CH27/EX27.15/Ex27_15.sce b/2510/CH27/EX27.15/Ex27_15.sce new file mode 100755 index 000000000..e2cee42fe --- /dev/null +++ b/2510/CH27/EX27.15/Ex27_15.sce @@ -0,0 +1,14 @@ +//Key: +//f(x) : Objective Function +//ci(x)'s : Constraints + +//Variable Declaration: +function [ans] = f(x) + ans = -1.70*x(1) - 2*x(2) +endfunction + +//Calculation +X = [7500,6000] + +//Result: +printf("Maximum Profit is $ %.1f /day or $ %.1f /year",-f(X),-365*f(X)) diff --git a/2510/CH27/EX27.5/Ex27_5.sce b/2510/CH27/EX27.5/Ex27_5.sce new file mode 100755 index 000000000..df8b3aac0 --- /dev/null +++ b/2510/CH27/EX27.5/Ex27_5.sce @@ -0,0 +1,16 @@ + +//Variable declaration: +i = 0.03375 //Rate of interest (%) +n = 9 //Years to the end of life (yr) +P = 60000 //Cost of exchanger ($) +L = 500 //Salvage value ($) +x = 5 //Time after 5 years (yr) + +//Calculation: +SFDF = i/((1+i)**n-1) //Sinking fund depreciation factor +UAP = (P-L)*SFDF //Uniform annual payment ($) +B = ceil(P-((P-L)/n)*x) //Appraisal value after 5 years ($) + +//Result: +printf("1. The uniform annual payment made into the fund at the of the year is : $ %.0f",UAP) +printf("2. The appraisal value of the exchanger at the end of the fifth year is : $ %.0f",B) diff --git a/2510/CH27/EX27.6/Ex27_6.sce b/2510/CH27/EX27.6/Ex27_6.sce new file mode 100755 index 000000000..09eaf1a32 --- /dev/null +++ b/2510/CH27/EX27.6/Ex27_6.sce @@ -0,0 +1,19 @@ +//Variable declaration: +C = 150000 //Capital cost ($) +i = 7/100 //Interest rate +n = 5 //Time (yr) +OC = 15000 //Operating cost ($) +A = 75000 //Annual cost for the old process ($) + +//Calculation: +CRF = (i*(1+i)**n)/((1+i)**n-1) //Capital recovery factor +IC = CRF*C //Initial cost ($) +AC = IC+OC //Total annualized cost ($) + +//Result: +printf("The annualized cost for the new heating system is : $ %.0f",AC) +if (AC<A) then + printf("Since this cost is lower than the annual cost of $75,000 for the old process, the proposed plan should be implemented.") +else + printf("Since this cost is higher than the annual cost of $75,000 for the old process, the proposed plan should not be implemented.") +end diff --git a/2510/CH27/EX27.7/Ex27_7.sce b/2510/CH27/EX27.7/Ex27_7.sce new file mode 100755 index 000000000..e8db5cd70 --- /dev/null +++ b/2510/CH27/EX27.7/Ex27_7.sce @@ -0,0 +1,26 @@ +//Variable declaration: +i = 12/100 //Intersest rate +n = 12 //Lifetime period (yr) +CC = 2625000 //Capital cost ($) +IC = 1575000 //Installation cost ($) +//From table 27.3: +Ic1 = 2000000 //Income credit for double pipe ($/yr) +Ic2 = 2500000 //Income credit for Shell-and-tube ($/yr) +AC1 = 1728000 //Total annual cost for double pipe ($/yr) +AC2 = 2080000 //Total annual cost for Shell-and-tube ($/yr) + +//Calculation: +CRF = i/(1-(1+i)**-n) //Capital recovery factor +DPc = (CC+IC)*CRF //Annual capital and installation costs for the DP unit ($/yr) +STc = (CC+IC)*CRF //Annual capital and installation costs for the ST unit ($/yr) +DPp = Ic1-AC1 //Profit for the DP unit ($/yr) +STp = Ic2-AC2 //Profit for the ST unit ($/yr) + +//Result: +printf("The profit for the shell-and-tube unit is : $ %.0f /yr .",DPp) +printf("The profit for the double pipe unit is : $ %.0f /yr .",STp) +if (STp>DPp) then + printf("A shell-and-tube heat exchanger should therefore be selected based on the above economic analysis.") +else + printf("A double pipe heat exchanger should therefore be selected based on the above economic analysis.") +end diff --git a/2510/CH27/EX27.8/Ex27_8.sce b/2510/CH27/EX27.8/Ex27_8.sce new file mode 100755 index 000000000..00caf42fa --- /dev/null +++ b/2510/CH27/EX27.8/Ex27_8.sce @@ -0,0 +1,52 @@ +//Variable declaration: +m = 50000 //Mass flowrate of the organic fluid (lb/h) +cP = 0.6 //The heat capacity of the organic liquid (Btu/lb. F) +T1 = 150 //Initial temperature of organic fluid ( F) +T2 = 330 //Final temperature of organic fluid ( F) +Ts1 = 358 //Saturation temperature for 150 psia ( F) +Ts2 = 417 //Saturation temperature for 300 psia ( F) +L1 = 863.6 //Latent heat for 150 psia (Btu/lb) +L2 = 809 //Latent heat for 300 psia (Btu/lb) +c1 = 5.20/1000 //Cost for 150 psia ($/lb) +c2 = 5.75/1000 //Cost for 300 psia ($/lb) +CI1 = 230 //Cost index in 1998 +CI2 = 360 //Cost index in 2011 +IF = 3.29 //Installation factor +PF1 = 1.15 //Pressure factors for 100 to 200 psig +PF2 = 1.20 //Pressure factors for 200 to 300 psig +OP = 90/100 //Plant on-stream operation factor +h = 365*24 //Hours in a year (h) + +//Calculation: +Q = m*cP*(T2-T1) //Overall heta duty (Btu/h) +DT1 = Ts1-T1 //Temperature driving force 1 for 150 psia ( F) +DT2 = Ts1-T2 //Temperature driving force 2 for 150 psia ( F) +LMTD1 = (DT1-DT2)/log(DT1/DT2) //Log-mean temperature difference for 150 psia ( F) +DT3 = Ts2-T1 //Temperature driving force 1 for 300 psia ( F) +DT4 = Ts2-T2 //Temperature driving force 2 for 300 psia ( F) +LMTD2 = (DT3-DT4)/log(DT3/DT4) //Log-mean temperature difference for 1300 psia ( F) +A1 = Q/(138*LMTD1) //Required heat transfer area for 150 psia (ft^2) +A2 = Q/(138*LMTD2) //Required heat transfer area for 300 psia (ft^2) +BC1 = 117*A1**0.65 //Base cost for 150 psia ($) +BC2 = 117*A2**0.65 //Base cost for 13000 psia ($) +C1 = BC1*(CI2/CI1)*IF*PF1 //Capital cost for 150 psia ($) +C2 = BC2*(CI2/CI1)*IF*PF2 //Capital cost for 300 psia ($) +S1 = Q*(h*OP)/L1 //Steam requirement for 150 psia (lb/yr) +S2 = Q*(h*OP)/L2 //Steam requirement for 300 psia (lb/yr) +SC1 = S1*c1 //Annual steam cost for 150 psia ($/yr) +SC2 = S2*c2 //Annual steam cost for 300 psia ($/yr) +C1 = round(C1*10**-3)/10**-3 +C2 = round(C2*10**-3)/10**-3 +SC1 = round(SC1*10**-3)/10**-3 +SC2 = round(SC2*10**-3)/10**-3 + +//Result: +printf("1. The capital cost for 150 psia is : $ %f",C1) +printf(" The capital cost for 300 psia is : $ %f",C2) +printf("2. The annual steam cost for 150 psia is : $ %f /yr .",SC1) +printf(" The annual steam cost for 300 psia is : $ %f /yr .",SC2) +if (C1<C2 & SC1>SC2) then + printf("The 300-psia exchanger costs less to purchase and install, but it costs more to operate. Choosing the more expensive, 150-psia exchanger is the obvious choice.") +else if (C1>C2 & SC1<SC2) then + printf("The 150-psia exchanger costs less to purchase and install, but it costs more to operate. Choosing the more expensive, 300-psia exchanger is the obvious choice.") +end diff --git a/2510/CH27/EX27.9/Ex27_9.sce b/2510/CH27/EX27.9/Ex27_9.sce new file mode 100755 index 000000000..cadcb41d4 --- /dev/null +++ b/2510/CH27/EX27.9/Ex27_9.sce @@ -0,0 +1,38 @@ +//Variable declaration: +TCC_TB = 2500000 //Total capital cost ($) +R_TB = 3600000 //R_TBevenue generated from the facility ($) +AOC_TB = 1200000 //Annual operating costs ($) +TCC_FB = 3500000 //Total capital cost ($) +R_FB = 5300000 //R_TBevenue generated from the facility ($) +AOC_FB = 1400000 //Annual operating costs ($) +n = 10 //Time of facility (yr) + +//Calculation: +D = 0.1*TCC_TB //Depriciation ($) +WC = 0.1*TCC_TB //Working capital ($) +TI = R_TB-AOC_TB-D //Taxable income ($) +IT = 0.5*TI //Income tax to be paid ($) +A = R_TB-AOC_TB-IT //After-tax cash flow ($) +function [ans] = eqTB(i) + x = (((1+i)**n-1)/(i*(1+i)**n))*A + (1/(1+i)**n)*WC //Equation for computing rate of return for TB unit + y = WC + 0.5*TCC_TB + 0.5*TCC_TB*(1+i)**1 //Equation for computing rate of return for TB unit + ans = x-y +endfunction +iTB = ceil(fsolve(0.8,eqTB)*100) //Rate of return for TB unit (%) + +D = 0.1*TCC_FB //Depriciation ($) +WC = 0.1*TCC_FB //Working capital ($) +TI = R_FB-AOC_FB-D //Taxable income ($) +IT = 0.5*TI //Income tax to be paid ($) +A = R_FB-AOC_FB-IT //After-tax cash flow ($) + +function [ans] = eqFB(i) + x = (((1+i)**n-1)/(i*(1+i)**n))*A + (1/(1+i)**n)*WC //Equation for computing rate of return for FB unit + y = WC + 0.5*TCC_FB + 0.5*TCC_FB*(1+i)**1 //Equation for computing rate of return for FB unit + ans = x-y +endfunction +iFB = fsolve(0.8,eqFB)*100 //Rate of return for FB unit (%) + +//Results: +printf("The rate of return for TB unit is: %.0f %%",iTB) +printf("The rate of return for FB unit is: %.1f %%",iFB) diff --git a/2510/CH28/EX28.11/Ex28_11.sce b/2510/CH28/EX28.11/Ex28_11.sce new file mode 100755 index 000000000..5136800b1 --- /dev/null +++ b/2510/CH28/EX28.11/Ex28_11.sce @@ -0,0 +1,53 @@ +//Variable declaration: +//From table 28.3: +//For stream 1 to be heated: +hm1 = 50000 //Mass flowrate (lb/h) +hcP1 = 0.65 //Heat capacity (Btu/lb. F) +hTi1 = 70 //Inlet temperature ( F) +hTo1 = 300 //Outlet temperature ( F) +//For stream 2 to be heated: +hm2 = 60000 //Mass flowrate (lb/h) +hcP2 = 0.58 //Heat capacity (Btu/lb. F) +hTi2 = 120 //Inlet temperature ( F) +hTo2 = 310 //Outlet temperature ( F) +//For stream 3 to be heated: +hm3 = 80000 //Mass flowrate (lb/h) +hcP3 = 0.78 //Heat capacity (Btu/lb. F) +hTi3 = 90 //Inlet temperature ( F) +hTo3 = 250 //Outlet temperature ( F) +//From table 28.4: +//For stream 1 to be cooled: +cm1 = 60000 //Mass flowrate (lb/h) +ccP1 = 0.70 //Heat capacity (Btu/lb. F) +cTi1 = 420 //Inlet temperature ( F) +cTo1 = 120 //Outlet temperature ( F) +//For stream 2 to be cooled: +cm2 = 40000 //Mass flowrate (lb/h) +ccP2 = 0.52 //Heat capacity (Btu/lb. F) +cTi2 = 300 //Inlet temperature ( F) +cTo2 = 100 //Outlet temperature ( F) +//For stream 3 to be cooled: +cm3 = 35000 //Mass flowrate (lb/h) +ccP3 = 0.60 //Heat capacity (Btu/lb. F) +cTi3 = 240 //Inlet temperature ( F) +cTo3 = 90 //Outlet temperature ( F) + +//Calculation: +H1 = hm1*hcP1*(hTo1-hTi1) //Heating duty for stream 1 (Btu/h) +H2 = hm2*hcP2*(hTo2-hTi2) //Heating duty for stream 2 (Btu/h) +H3 = hm3*hcP3*(hTo3-hTi3) //Heating duty for stream 1 (Btu/h) +H = H1+H2+H3 //Total heating duty (Btu/h) +C1 = cm1*ccP1*(cTi1-cTo1) //Cooling duty for stream 1 (Btu/h) +C2 = cm2*ccP2*(cTi2-cTo2) //Cooling duty for stream 2 (Btu/h) +C3 = cm3*ccP3*(cTi3-cTo3) //Cooling duty for stream 1 (Btu/h) +C = C1+C2+C3 //Total Cooling duty (Btu/h) + +//Result: +printf("Table: Duty Requirements.") +printf("Stream Duty, Btu/h") +printf("1 %.0f",H1) +printf("2 %.0f",H2) +printf("3 %.0f",H3) +printf("4 %.0f",C1) +printf("5 %.0f",C2) +printf("6 %.0f",C3) diff --git a/2510/CH3/EX3.11/Ex3_11.sce b/2510/CH3/EX3.11/Ex3_11.sce new file mode 100755 index 000000000..59debe696 --- /dev/null +++ b/2510/CH3/EX3.11/Ex3_11.sce @@ -0,0 +1,19 @@ +//Variable declaration: +D = 5 //Diameter of pipe (ft) +V = 10 //Fluid velocity (ft/s) +p = 50 //Fluid density (lb/ft^3) +u = 0.65 //Fluid viscosity (lb/ft.s) +F = 1.0/12.0 //Feet in an inch +VCp = 6.72*10**-4 //Viscosity of centipoise (lb/ft.s) + +//Calculation: +A = D*V*p*F/u/VCp //Reynolds Number + +//Result: +if(A>2100) then + printf("The Reynolds number is :%.0f therefore, the flow is turbulent.",A) +else + if(A<2100) then + printf("The Reynolds number is : %f therefore, the flow is not turbulent.",A) +end +end; diff --git a/2510/CH3/EX3.12/Ex3_12.sce b/2510/CH3/EX3.12/Ex3_12.sce new file mode 100755 index 000000000..b6522f3d2 --- /dev/null +++ b/2510/CH3/EX3.12/Ex3_12.sce @@ -0,0 +1,16 @@ +//Variable declaration: +//For the problem at hand, take as a basis 1 kilogram of water and assume the potential energy to be zero at ground level conditions. +z1 = 0 //Intial height from ground level (m) +z2 = 10 //Final height from ground level (m) +PE1 = 0 //Initial potential energy at z1 (J) +m = 1 //Mass of water (kg) +g = 9.8 //Gravitational acceleration (m/s^2) +gc = 1 //Conversion factor + +//Calculations: +PE2 = m*(g/gc)*z2 //Final potential energy at z2 (J) + +//Result: +disp("The potential energy of water is :") +disp(PE2) +disp("J ") diff --git a/2510/CH3/EX3.2/Ex3_2.sce b/2510/CH3/EX3.2/Ex3_2.sce new file mode 100755 index 000000000..4f8751b90 --- /dev/null +++ b/2510/CH3/EX3.2/Ex3_2.sce @@ -0,0 +1,29 @@ + +//Variable Declaration: +Q1 = 8.03 //Years(part 1) +D = 365 //Days in a year +H = 24 //Hours in a day +M = 60 //Minutes in an hour +S = 60 //Seconds in a minute +Q2 = 150 //Miles per hour(part 2) +FM = 5280 //Feet in a mile +YF = 1.0/3.0 //Yard in a feet +Q3 = 100 //Meter per second square(part 3) +Cmm = 100 //Centimeter in a meter +FC = 1.0/30.48 //Feet in a centimeter +SsMs = 60**2 //Second square in a minute square +Q4 = 0.03 //Gram per centimeter cube (part 4) +PG = 1.0/454.0 //Pound in a gram +CF = (30.48)**3 //Centimeter in a feet + +//Calculation: +A1 = Q1*D*H*M*S //Seconds (s) +A2 = Q2*FM*YF //Yards per hour (yd/hr) +A3 = Q3*Cmm*FC*SsMs //Feet per min square (ft/min^2) +A4 = Q4*PG*CF //Pound per feet cube (lb/ft^3) + +//Results: +printf("1. Seconds in %f year is: %f x 10**8 s",Q1,A1/10**8) +printf("2. Yards per hour in %f miles per hour is: %f x 10**5 yd/h",Q2,A2/10**5) +printf("3. Feets per minute square in %f meter per square is: %f x 10**6 ft/min^2",Q3,A3/10**6) +printf("4. Pounds per feet cube in %f gram per centimeter cube is: %.0f lb/ft^3",Q4,A4) diff --git a/2510/CH3/EX3.3/Ex3_3.sce b/2510/CH3/EX3.3/Ex3_3.sce new file mode 100755 index 000000000..2eff7559d --- /dev/null +++ b/2510/CH3/EX3.3/Ex3_3.sce @@ -0,0 +1,22 @@ +//Variable Declaration: +Q1 = 32.2 //Gravitational acceleration (ft/s^2) (part 1) +CF = 32.2 //Conversion factor (lb.ft/lbf.s^2) +M = 100 //Mass (lb) +SA = 3 //Surface area (in^2) +FsIs = (1.0/12.0)**2 //Feet square in a inch square +Q2 = 14.7 //Atmospheric pressure (psi) (part 2) +GP = 35 //Gauge Pressure (psig) + +//Caculations: +F = M*Q1/CF //Force (lbf) +P = F/SA/FsIs //Pressure at the base (lbf/ft^2) +Pa = GP+Q2 //Absolute pressure (psia) + +//Results: +disp("1. Pressure at the base is:") +disp(P) +disp("lbf/ft^2") + +disp("2. Absolute pressure is:") +disp(Pa) +disp("psia") diff --git a/2510/CH3/EX3.4/Ex3_4.sce b/2510/CH3/EX3.4/Ex3_4.sce new file mode 100755 index 000000000..97904c66b --- /dev/null +++ b/2510/CH3/EX3.4/Ex3_4.sce @@ -0,0 +1,25 @@ +//Variable Declaration: +Q1 = 20.0 //Mass (lb) (part 1) +MH = 1.008 //Molecular weight of H (lb/lbmol) +MO = 15.999 //Molecular weight of O (lb/lbmol) +Q2 = 454 //Gram in pound (part 2) +Q3 = 6.023*10**23 //Avogadro nuber (part 3) + +//Calculations: +Mol = 2*MH+MO //Molecular weight of water (lb/lbmol) +A1 = Q1/Mol //Pound.moles of water (lbmol) +A2 = Q1*Q2/Mol //Gram.moles of water (gmol) +A3 = A2*Q3 //Molecules of water (molecules) + +//Results: +disp("1. Pound.moles of water is:") +disp(A1) +disp("lbmol water") + +disp("2. Gram.moles of water is:") +disp(A2) +disp("gmol water") + +disp("3. Molecules of water is:") +disp(A3/10**26) +disp(" x 10**26 molecules") diff --git a/2510/CH3/EX3.5/Ex3_5.sce b/2510/CH3/EX3.5/Ex3_5.sce new file mode 100755 index 000000000..df5df16b0 --- /dev/null +++ b/2510/CH3/EX3.5/Ex3_5.sce @@ -0,0 +1,11 @@ +//Variable declaration: +SG = 0.92 //Specific gavity of liquid, methanol +DW = 62.4 //Density of reference substance, water (lb/ft^3) + +//Calculation: +DM = SG*DW //Density of methanol (lb/ft^3) + +//Result: +disp("Density of methanol is:") +disp(DM) +disp("lb/ft^3") diff --git a/2510/CH3/EX3.6/Ex3_6.sce b/2510/CH3/EX3.6/Ex3_6.sce new file mode 100755 index 000000000..4886b70c5 --- /dev/null +++ b/2510/CH3/EX3.6/Ex3_6.sce @@ -0,0 +1,16 @@ +//Variable declaration: +SG = 0.8 //Specific Gravity +AV = 0.02 //Absolute Viscosity (cP) +cP = 1 //Viscosity of centipoise (cP) +VcP = 6.72 * 10**-4 //Pound per feet.sec in a centipoise (lb/ft.s) +pR = 62.43 //Reference density (lb/ft^3) + +//Calculations: +u = AV*VcP/cP //Viscosity of gas (lb/ft.s) +p = SG*pR //Density of gas (lb/ft^3) +v = u/p //Kinematic viscosity of gas (ft^2/s) + +//Result: +disp("Kinematic viscosity of gas is:") +disp(v/10**-7) +disp ("x 10**-7 ft^2/s") diff --git a/2510/CH3/EX3.7/Ex3_7.sce b/2510/CH3/EX3.7/Ex3_7.sce new file mode 100755 index 000000000..825f021aa --- /dev/null +++ b/2510/CH3/EX3.7/Ex3_7.sce @@ -0,0 +1,13 @@ +//Variable declaration: +X = 7.0 //Coordinate X of H2SO4 +Y = 24.8 //Coordinate Y of H2SO4 +S = 45 //Slope + +//Calculations: +//From the figure C.1 we found the intersection of curves mu = 12cP +mu = 12 + +//Results: +disp("Absolute viscosity of a 98% sulfuric acid solution at 45° C is :") +disp(mu*10**-2) +disp(" g/cm.s") diff --git a/2510/CH3/EX3.8/Ex3_8.sce b/2510/CH3/EX3.8/Ex3_8.sce new file mode 100755 index 000000000..cfc2faa33 --- /dev/null +++ b/2510/CH3/EX3.8/Ex3_8.sce @@ -0,0 +1,13 @@ +//Variable declaration: +CpM = 0.61 //Heat capacity of methanol (cal/g.°C) +G = 454 //Grams in a pound +B = 1.0/252.0 //Btu in a calorie +C = 1.0/1.8 //Degree celsius in a degree fahrenheit + +//Calculation: +Cp = CpM*G*B*C //Heat capacity in English units (Btu/lb.°F) + +//Result: +disp("Heat capacity in English units is: ") +disp(Cp) +disp(" Btu/lb.°F") diff --git a/2510/CH3/EX3.9/Ex3_9.sce b/2510/CH3/EX3.9/Ex3_9.sce new file mode 100755 index 000000000..5d7f698e0 --- /dev/null +++ b/2510/CH3/EX3.9/Ex3_9.sce @@ -0,0 +1,14 @@ +//Variable declaration: +kM = 0.0512 //Thermal conductivity of methanol (cal/m.s°C) +B = 1.0/252.0 //Btu in a calorie +M = 0.3048 //Meters in a feet +S = 3600 //Seconds in an hour +C = 1.0/1.8 //Degree celsius in a degree fahrenheit + +//Calculation: +k = kM*B*M*S*C //Thermal conductivity in English units (Btu/ft.h.°F) + +//Result: +disp("Thermal coductivity in English units is:") +disp(k) +disp("Btu/ft.h.°F") diff --git a/2510/CH4/EX4.1/Ex4_1.sce b/2510/CH4/EX4.1/Ex4_1.sce new file mode 100755 index 000000000..51f82ff30 --- /dev/null +++ b/2510/CH4/EX4.1/Ex4_1.sce @@ -0,0 +1,28 @@ +//Variable declaration: +Vx_in = 420 //Entry Velocity in X direction (m/s) +Vx_out = 0 //Exit Velocity in X direction (m/s) +Vy_in = 0 //Entry Velocity in Y direction (m/s) +Vy_out = 420 //Exit Velocity in Y direction (m/s) +m = 0.15 //Rate of water entrained by the steam (kg/s) +lb = 1.0/4.46 //Pound force in a newton force + +//Calculations: +Mx_out = m*Vx_out //Rate of change of momentum at entry in x-direction (kg.m) +Mx_in = m*Vx_in //Rate of change of momentum at exit in x-direction (kg.m) +My_out = m*Vy_out //Rate of change of momentum at entry in y-direction (kg.m) +My_in = m*Vy_in //Rate of change of momentum at exit in y-direction (kg.m) +Fxgc = (Mx_out - Mx_in)*lb //Force in X direction (lbf) +Fygc = (My_out - My_in)*lb //Force in X direction (lbf) + +//Results: +if Fxgc < 1 then + printf ("The x-direction supporting force acting on the 90° elbow is : %.1f lbf acting toward the left.",-Fxgc) +else + printf ("The x-direction supporting force acting on the 90° elbow is : %.1f lbf acting toward the right.",Fxgc) +end + +if Fygc < 1 then + printf ("The y-direction supporting force acting on the 90° elbow is : %.1f lbf acting downwards.",-Fygc) +else + printf ("The y-direction supporting force acting on the 90° elbow is : %.1f lbf acting upwards.",Fygc) +end diff --git a/2510/CH4/EX4.10/Ex4_10.sce b/2510/CH4/EX4.10/Ex4_10.sce new file mode 100755 index 000000000..6fb1732cc --- /dev/null +++ b/2510/CH4/EX4.10/Ex4_10.sce @@ -0,0 +1,11 @@ +//Variable declaration: +T_c1 = 20 //Initial cold fluid temperature (°C) +T_h1 = 82 //Initial hot fluid temperature (°C) +T_h2 = 94 //Final hot fluid temperature (°C) + +//Calculation: +T_c2 = (T_h2 - T_h1 + T_c1) //Final cold fluid temperature (°C) + +//Result: +printf ("The heat transfer rate is: %.0f °C",T_c2) +printf ("There is a printing mistake in book regarding unit of the final result.") diff --git a/2510/CH4/EX4.11/Ex4_11.sce b/2510/CH4/EX4.11/Ex4_11.sce new file mode 100755 index 000000000..a7013a81f --- /dev/null +++ b/2510/CH4/EX4.11/Ex4_11.sce @@ -0,0 +1,11 @@ +//Variable declaration: +Q = -5.5*10**6 //The heat transferred out from the gas (W) +Cp = 1090.0 //The average heat capacity of the gas (J/(kg . °C)) +m = 9.0 //The gas mass flow rate (kg/s) +T1 = 650 //The gas inlet temperature (°C) + +//Calculation: +T2 = Q/(m*Cp)+T1 //The gas outlet temperature (°C) + +//Result: +printf ("The gas outlet temperature is : %.0f °C",T2) diff --git a/2510/CH4/EX4.12/Ex4_12.sce b/2510/CH4/EX4.12/Ex4_12.sce new file mode 100755 index 000000000..f7fad88f9 --- /dev/null +++ b/2510/CH4/EX4.12/Ex4_12.sce @@ -0,0 +1,22 @@ +//Variable declaration: +n = 3500.0 //Inlet flowrate of water (gal/min) +Cp_W = 75.4 //Heat capacity of water (J/(gmol . °C) +p = 62.4 //Density of water (lb/ft^3) +M = 24*60.0 //Minutes in a day (min/day) +G = 7.48 //Gallons in a feet cube (gal/ft^3) +gm = 454.0 //Grams in a pound (g/lb) +J = 1054.0 //Joules in a Btu (J/Btu) +g = 18.0 //Grams in a gmol (g/gmol) +F = 1.8 //Degree fahrenheit in a degree celcius (°F) +Ti = 38.0 //Initial temperature (°F) +Tf = 36.2 //Final temperature (°F) + +//Calculations: +T= Ti-Tf //Temperature loss (°F) +m = n*p*M/G //Mass flow rate of water (lb/day) +Cp = Cp_W*gm/J/g/F //Heat capacity in cosistent units (Btu/(lb.°F)) +Q = m*Cp*T //Rate of heat flow from water (Btu/day) + +//Result: +printf ("The rate of Btu removed from the water per day is : %.2f x 10**8 Btu/day.",Q/10**8) +printf ("There is a calculation mistake in the book regarding the final result.") diff --git a/2510/CH4/EX4.2/Ex4_2.sce b/2510/CH4/EX4.2/Ex4_2.sce new file mode 100755 index 000000000..e67290cdf --- /dev/null +++ b/2510/CH4/EX4.2/Ex4_2.sce @@ -0,0 +1,19 @@ +//Variable declaration: +Fx = -63 //Force component in X direction (N) +Fy = 63 //Force component in Y direction (N) +lbf = 0.22481 //Pound-forrce in unit newton (lbf) + +//Calculations: +Fr = sqrt(Fx**2 + Fy**2)*lbf //The resultant supporting force (lbf) +u = atand(Fy,Fx) //Angle between the positive x axis and the direction of the force (degrees) + +//Result: +if ( 0<u & u<90 ) then + printf ("The supporting force is : %.1f lbf acting at %f ° i.e in the northeast direction.",Fr,u) +elseif (90<u & u<180) then + printf ("The supporting force is : %.1f lbf acting at %f ° i.e in the northwest direction.",Fr,u) +elseif (180<u & u<270) then + printf ("The supporting force is : %.1f lbf acting at %f ° i.e in the southwest direction.",Fr,u) +elseif (270<u & u<360) then + printf ("The supporting force is : %.1f lbf acting at %f ° i.e in the southeast direction.",Fr,u) +end diff --git a/2510/CH4/EX4.3/Ex4_3.sce b/2510/CH4/EX4.3/Ex4_3.sce new file mode 100755 index 000000000..ccf8aef07 --- /dev/null +++ b/2510/CH4/EX4.3/Ex4_3.sce @@ -0,0 +1,11 @@ +//Variable declaration: +R1_in = 10000 //Rate of fuel fed into the boiler (lb/h) +R2_1n = 20000 //Rate of air fed into the boiler (lb/h) +R3_in = 2000 //Rate of methane fed into the boiler (lb/h) + +//Calculations: +m_in = R1_in + R2_1n + R3_in //Rate of mass in (lb/h) +m_out = m_in //Rate of mass out (lb/h) + +//Result: +printf ("The rate of the product gases exit from the incinerator is : %.0f lb/h",m_in) diff --git a/2510/CH4/EX4.4/Ex4_4.sce b/2510/CH4/EX4.4/Ex4_4.sce new file mode 100755 index 000000000..f7d86824a --- /dev/null +++ b/2510/CH4/EX4.4/Ex4_4.sce @@ -0,0 +1,14 @@ +//Variable declaration: +E1 = 65 //Efficiency of spray tower (%) +E2 = 98 //Efficiency of packed column (%) +m_in = 76 //Mass flow rate of HCl entering the system (lb/h) + +//Calculations: +m1_out = (1 - E1/100.0)*m_in //Mass flow rate of HCl leaving the spray tower (lb/h) +m2_out = (1 - E2/100.0)*m1_out //Mass flow rate of HCl entering the packed column (lb/h) +E = (m_in - m2_out)/m_in //Overall fractional efficiency (%) + +//Result: +printf ("The mass flow rate of HCl leaving the spray tower is : %.2f lb/h HCL",m1_out) +printf ("The mass flow rate of HCl entering the packed column is : %.3f lb/h HCL",m2_out) +printf ("The overall fractional efficiency is : %.2f %%",E*100) diff --git a/2510/CH4/EX4.5/Ex4_5.sce b/2510/CH4/EX4.5/Ex4_5.sce new file mode 100755 index 000000000..c6b406a3f --- /dev/null +++ b/2510/CH4/EX4.5/Ex4_5.sce @@ -0,0 +1,12 @@ +//Variable declaration: +m1 = 1000 //Flowrate data 1 (lb/min) +m2 = 1000 //Flowrate data 2 (lb/min) +m4 = 200 //Flowrate data 4 (lb/min) + +//Calculations: +m5 = m1 + m2 - m4 //Flowrate data 5 (lb/min) +m6 = m2 //Flowrate data 6 (lb/min) +m = m5 - m6 //Flowrate of water lost in operation (lb/min) + +//Result: +printf ("The amount of water lost by evaporation in the operation is %.0f lb/min",m) diff --git a/2510/CH4/EX4.6/Ex4_6.sce b/2510/CH4/EX4.6/Ex4_6.sce new file mode 100755 index 000000000..b9702a842 --- /dev/null +++ b/2510/CH4/EX4.6/Ex4_6.sce @@ -0,0 +1,29 @@ +//Variable declaration: +q1 = 1000.0 //Volumetric flowrate from tank 1 (gal/day) +q2 = 1000.0 //Volumetric flowrate from tank 2 (gal/day) +q3 = 2000.0 //Volumetric flowrate from tank 3 (gal/day) +q4 = 200.0 //Volumetric flowrate from tank 4 (gal/day) +q5 = 1800.0 //Volumetric flowrate from tank 5 (gal/day) +q6 = 1000.0 //Volumetric flowrate from tank 6 (gal/day) +C1 = 4.0 //Phosphate concentration in tank 1 (ppm) +C2 = 0.0 //Phosphate concentration in tank 2 (ppm) +C3 = 2.0 //Phosphate concentration in tank 3 (ppm) +C4 = 20.0 //Phosphate concentration in tank 4 (ppm) +C5 = 0.0 //Phosphate concentration in tank 5 (ppm) +C6 = 0.0 //Phosphate concentration in tank 6 (ppm) +Cf = 120000.0 //conversion factor for water (gal/10**6lb) + +//Calculations: +C1q1 = C1*q1/Cf //Data 1 (lb/day) +C2q2 = C2*q2/Cf //Data 2 (lb/day) +C3q3 = C3*q3/Cf //Data 3 (lb/day) +C4q4 = C4*q4/Cf //Data 4 (lb/day) +C5q5 = C5*q5/Cf //Data 5 (lb/day) +C6q6 = C6*q6/Cf //Data 6 (lb/day) + +//Results: +if (((C1q1 + C2q2) == C3q3) & C3q3 == (C4q4 + C5q5) & C5q5 == C6q6 & C2q2 == C6q6) then + printf("The data appear to be consistent .") +else + printf ("The data appear to be inconsistent .") +end diff --git a/2510/CH4/EX4.7/Ex4_7.sce b/2510/CH4/EX4.7/Ex4_7.sce new file mode 100755 index 000000000..7ec8f26c7 --- /dev/null +++ b/2510/CH4/EX4.7/Ex4_7.sce @@ -0,0 +1,17 @@ +//Variable declaration: +Dz = 3000 //Height (ft) +V0 = 500000 //Flowrate of water (gal/min) +n = 30 //Turbine efficiency (%) +m = 0.3048 //Meters in a feet +m3 = 0.00378 //Meters-cube in a gallon +g = 9.8 //Gravitational acceleration (m/s^2) +gc = 1 //Conversion factor +MW = 10**(-6) //Megawatt in newton-meter-per-second + +//Calculations: +V1 = (V0*m3)*1000.0/60.0 //The mass flow rate of the water in kilograms/second (kg/s) +DPE = V1*g*Dz*m/gc*MW //The loss in potential energy (MW) +AP = n/100.0*DPE //The actual power output (MW) + +//Result: +printf ("The power generated by the lake located is : %.1f MW",AP) diff --git a/2510/CH4/EX4.8/Ex4_8.sce b/2510/CH4/EX4.8/Ex4_8.sce new file mode 100755 index 000000000..92214d114 --- /dev/null +++ b/2510/CH4/EX4.8/Ex4_8.sce @@ -0,0 +1,10 @@ +//Variable declaration: +n = 111.4 //Flowrate of air stream (lbmol/min) +H1 = 1170 //Average heat capacity at 200°F (Btu/lbmol) +H2 = 4010 //Average heat capacity at 600°F (Btu/lbmol) + +//Calculation: +Q = n*(H2 - H1) //The heat transfer rate (Btu/min) + +//Result: +printf ("The heat transfer rate required is: %.2f x 10**5 Btu/min",Q/10**5) diff --git a/2510/CH4/EX4.9/Ex4_9.sce b/2510/CH4/EX4.9/Ex4_9.sce new file mode 100755 index 000000000..b40ef03b5 --- /dev/null +++ b/2510/CH4/EX4.9/Ex4_9.sce @@ -0,0 +1,12 @@ +//Variable declaration: +n = 600 //The mass flow rate of fluid (lbmol/min) +Cp_AV = 0.271 //Heat capacity (Btu/lbmol . °F) +T1 = 200 //Initial temperature(°F) +T2 = 600 //Final temperature(°F) + +//Calcultaion: +Q = n*Cp_AV*(T2 - T1) //The required heat rate (Btu/min) +Q = Q - modulo(Q,1000) + +//Result: +printf ("The required heat rate is : %.0f Btu/min",Q) diff --git a/2510/CH5/EX5.1/Ex5_1.sce b/2510/CH5/EX5.1/Ex5_1.sce new file mode 100755 index 000000000..dcc6c82d4 --- /dev/null +++ b/2510/CH5/EX5.1/Ex5_1.sce @@ -0,0 +1,12 @@ +//Variable declaration: +qi = 3500 //Initial volumetric flow rate of gas (acfm) +Ti = 100.0 //Initial temperature (°F) +Tf = 300.0 //Final temperature (°F) + +//Calculation: +Ti_R = Ti+460 //Initial temperatur in Rankine scale (°R) +Tf_R = Tf+460 //Final temperatur in Rankine scale (°R) +qf = qi*(Tf_R/Ti_R) //Final volumetric flow rate of gas (acfm) + +//Result: +printf("The final volumetric flow rate of gas is : %.0f acfm",qf) diff --git a/2510/CH5/EX5.10/Ex5_10.sce b/2510/CH5/EX5.10/Ex5_10.sce new file mode 100755 index 000000000..9ad34faca --- /dev/null +++ b/2510/CH5/EX5.10/Ex5_10.sce @@ -0,0 +1,22 @@ +//Variable declaration: +qs1 = 5000.0 //Volumetric flow rate of C6H5Cl at standard conditions (scfm) +qs2 = 3000.0 //Volumetric flow rate of air at standard conditions (scfm) +Ta = 70+460.0 //Actual absolute temperature in Rankine scale (°R) +Ts = 60+460.0 //Standard absolute temperature in Rankine scale (°R) +V = 387.0 //Volume occupied by one lbmol of any ideal gas (ft^3) +M1 = 112.5 //Molecular weight of C6H5Cl (lb/lbmol) +M2 = 29.0 //Molecular weight of air (lb/lbmol) +T = 60.0 //Absolute temperature (°F) + +//Calculations: +qa1 = qs1*(Ta/Ts) //Volumetric flow rate of C6H5Cl at actual conditions (acfm) +qa2 = qs2*(Ta/Ts) //Volumetric flow rate of air at actual conditions (acfm) +n1 = qa1/V //Molar flow rate of C6H5Cl (lbmol/min) +n2 = qa2/V //Molar flow rate of air (lbmol/min) +m1 = n1*M1*T //Mass flow rate of C6H5Cl (lb/h) +m2 = n2*M2*T //Mass flow rate of air (lb/h) +m_in = m1+m2 //Total mass flow rate of both streams entering the oxidizer (lb/h) +m_out = m_in //Total mass flow rate of both streams exit the cooler (lb/h) + +//Result: +printf("The rate of the products exit the cooler is : %.0f lb/h",m_out) diff --git a/2510/CH5/EX5.11/Ex5_11.sce b/2510/CH5/EX5.11/Ex5_11.sce new file mode 100755 index 000000000..f043391e8 --- /dev/null +++ b/2510/CH5/EX5.11/Ex5_11.sce @@ -0,0 +1,11 @@ +//Variable declaration: +p = 0.15 //Partial pressure of SO3 (mm Hg) +P = 760.0 //Atmospheric pressure (mm Hg) +m = 10**6 //Particles in a million + +//Calculation: +y = p/P //Mole fraction of SO3 +ppm = y*m //Parts per million of SO3 (ppm) + +//Result: +printf("The parts per million of SO3 in the exhaust is : %.0f ppm.",ppm) diff --git a/2510/CH5/EX5.2/Ex5_2.sce b/2510/CH5/EX5.2/Ex5_2.sce new file mode 100755 index 000000000..64bfcac93 --- /dev/null +++ b/2510/CH5/EX5.2/Ex5_2.sce @@ -0,0 +1,10 @@ +//Variable declaration: +qi = 3500 //Initial volumetric flow rate of gas (acfm) +Pi = 1.0 //Iitial pressure (atm) +Pf = 3.0 //Final pressure (atm) + +//Calculation: +qf = qi*(Pi/Pf) //Final volumetric flow rate of gas (acfm) + +//Result: +printf("The volumetric flow rate of the gas (100°F, 1 atm) is: %.0f acfm",qf) diff --git a/2510/CH5/EX5.3/Ex5_3.sce b/2510/CH5/EX5.3/Ex5_3.sce new file mode 100755 index 000000000..0b153c425 --- /dev/null +++ b/2510/CH5/EX5.3/Ex5_3.sce @@ -0,0 +1,12 @@ +//Variable declaration: +qi = 3500 //Initial volumetric flow rate of the gas (acfm) +Pi = 1.0 //Initial pressure (atm) +Pf = 3.0 //Final pressure (atm) +Tf = 300.0+460.0 //Final temperature in Rankine scale (°R) +Ti = 100.0+460.0 //Initial temperature in Rankine scale (°R) + +//Calculation: +qf = qi*(Pi/Pf)*(Tf/Ti) //Final volumetric flow rate of the gas (acfm) + +//Result: +printf("The volumetric flow rate of the gas at 300°F temperature is : %.0f acfm",qf) diff --git a/2510/CH5/EX5.4/Ex5_4.sce b/2510/CH5/EX5.4/Ex5_4.sce new file mode 100755 index 000000000..beeb4ad81 --- /dev/null +++ b/2510/CH5/EX5.4/Ex5_4.sce @@ -0,0 +1,11 @@ +//Variable declaration: +P = 14.7 //Absolute pressure of air (psia) +MW = 29 //Molecular weight of air (lb/lbmol) +T = 75+460 //Temperature in Rankine scale (°R) +R = 10.73 //Universal gas constant (ft^3.psi/lbmol.°R) + +//Calculation: +p = P*MW/R/T //Density of air (lb/ft^3) + +//Result: +printf("The density of air at 75°F and 14.7 psia is : %.4f lb/ft^3",p) diff --git a/2510/CH5/EX5.5/Ex5_5.sce b/2510/CH5/EX5.5/Ex5_5.sce new file mode 100755 index 000000000..edb919af8 --- /dev/null +++ b/2510/CH5/EX5.5/Ex5_5.sce @@ -0,0 +1,11 @@ +//Variable declaration: +n = 1 //Molar flow rate of gas (lbmol/h) +R = 10.73 //Universal gas constant (ft^3.psi/lbmol.°R) +T = 60+460 //Temperature in Rankine scale (°R) +P = 14.7 //Absolute pressure of gas (psia) + +//Calculation: +V = n*R*T/P //Volume of gas (ft^3) + +//Result: +printf("The volume of given ideal gas is : %.1f ft^3",V) diff --git a/2510/CH5/EX5.6/Ex5_6.sce b/2510/CH5/EX5.6/Ex5_6.sce new file mode 100755 index 000000000..05d1ba940 --- /dev/null +++ b/2510/CH5/EX5.6/Ex5_6.sce @@ -0,0 +1,11 @@ +//Variable declaration: +P = 1.2 //Abslute pressure of gas (psia) +MW = 29 //Molecular weight of gas (g/gmol) +R = 82.06 //Universal gas constant (atm.cm^3/gmol.K) +T = 20+273 //Temperature in Kelvin (K) + +//Calculation: +p = P*MW/R/T //Dendity of gas (g/cm^3) + +//Result: +printf("The density of given gas is : %.5f g/cm^3",p) diff --git a/2510/CH5/EX5.7/Ex5_7.sce b/2510/CH5/EX5.7/Ex5_7.sce new file mode 100755 index 000000000..98300a583 --- /dev/null +++ b/2510/CH5/EX5.7/Ex5_7.sce @@ -0,0 +1,12 @@ +//Variable declaration: +R = 10.73 //Universal gas constant (psia . ft^3/lbmol .°R) +T = 70+460 //Temperature in Rankine scale (°R) +v = 10.58 //Specific volume (ft^3/lb) +P = 14.7 //Absolute pressure (psia) + +//Calculation: +MW = R*T/v/P //Molecular weight of gas (lb/lbmol) + +//Result: +printf("The molecular weight of the gas is : %.2f lb/lbmol.",MW) +printf("It appears that the gas is HCl (i.e., hydrogen chloride).") diff --git a/2510/CH5/EX5.8/Ex5_8.sce b/2510/CH5/EX5.8/Ex5_8.sce new file mode 100755 index 000000000..a2a6077fb --- /dev/null +++ b/2510/CH5/EX5.8/Ex5_8.sce @@ -0,0 +1,10 @@ +//Variable declaration: +qs = 30000 //Volumetric flow rate at standard conditions (scfm) +Ta = 1100+460 //Actual absolute temperature in Rankine scale (°R) +Ts = 60+460 //Standard absolute temperature in Rankine scale (°R) + +//Calculation: +qa = qs*Ta/Ts //Volumetric flow rate at actual conditions (acfm) + +//Result: +printf("The volumetric flow rate in actual cubic feet per minute is : %.0f acfm",qa) diff --git a/2510/CH5/EX5.9/Ex5_9.sce b/2510/CH5/EX5.9/Ex5_9.sce new file mode 100755 index 000000000..316e78f43 --- /dev/null +++ b/2510/CH5/EX5.9/Ex5_9.sce @@ -0,0 +1,12 @@ +//Variable declaration: +qs = 1000 //Volumetric flow rate at standard conditions (scfm) +Ta = 300+460 //Actual absolute temperature in Rankine scale (°R) +Ts = 70+460 //Standard absolute temperature in Rankine scale (°R) +A = 2.0 //Inlet area of stack (ft^2) + +//Calculations: +qa = qs*Ta/Ts //Volumetric flow rate at actual conditions (acfm) +v = qa/A/60 //Velocity of gas (ft/s) + +//Result: +printf("The velocity of the gas through the stack inlet is : %.0f ft/s",v) diff --git a/2510/CH6/EX6.1/Ex6_1.sce b/2510/CH6/EX6.1/Ex6_1.sce new file mode 100755 index 000000000..050c8f3ba --- /dev/null +++ b/2510/CH6/EX6.1/Ex6_1.sce @@ -0,0 +1,10 @@ +//Variable declaration: +NPS = 2 //Nominal pipe size (inch) +SN = 40 //Schedule number + +//Calculation: +//From Table 6.2, we obtain that the inside diameter of steel pipe is ID = 2.067 in. +ID = 2.067 + +//Result: +printf("The inside diameter of steel pipe is : %f in.",ID) diff --git a/2510/CH6/EX6.11/Ex6_11.sce b/2510/CH6/EX6.11/Ex6_11.sce new file mode 100755 index 000000000..cc6a9db3e --- /dev/null +++ b/2510/CH6/EX6.11/Ex6_11.sce @@ -0,0 +1,13 @@ +//Variable declaration: +a = 1 //Length of cross-section (m) +b = 0.25 //Width of cross-section (m) +v = 1*10**-5 //Kinematic viscosity of air (m^2/s) +Re = 2300.0 //Reynolds Number +cm = 100 //Cenitmeters in a meter + +//Calculation: +Dh = 2*a*b/(a+b) //Hydraulic diameter of duct (m) +V = Re*v/Dh*cm //Maximum air velocity (cm/s) + +//Result: +printf("The maximum air velocity before the flow becomes turbulent is : %.1f cm/s.",V) diff --git a/2510/CH6/EX6.12/Ex6_12.sce b/2510/CH6/EX6.12/Ex6_12.sce new file mode 100755 index 000000000..8221ee5aa --- /dev/null +++ b/2510/CH6/EX6.12/Ex6_12.sce @@ -0,0 +1,17 @@ +//Variable declaration: +q = 0.486 //Flow rate of fluid (ft^3/s) +D = 2.0/12.0 //Diameter of tube in feet (ft) +pi = 3.14 //Value of pi +p = 70.0 //Density of fluid (lb/ft^3) +u = 0.1806 //Viscosity of fluid (lb/ft) + +//Calculation: +V = 4*q/pi/D**2 //Flow velocity (ft/s) +Re = D*V*p/u //Reynolds Number + +//Result: +if(Re<2100) then + printf("The flow is laminar.") +elseif(Re>2100) then + printf("The flow is turbulant.") +end diff --git a/2510/CH6/EX6.13/Ex6_13.sce b/2510/CH6/EX6.13/Ex6_13.sce new file mode 100755 index 000000000..9deea2297 --- /dev/null +++ b/2510/CH6/EX6.13/Ex6_13.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 6.12, we have: +D = 2.0/12.0 //Diameter of pipe in feet (ft) +Re = 1440.0 //Reynolds number + +//Calculation: +Lc = 0.05*D*Re //Length of pipe (ft) + +//Result: +printf("The pipe length to ensure a fully developed flow is: %f ft.",Lc) +printf("This is an abnormally long calming length for a pipe (or tube) in a heat exchanger.") diff --git a/2510/CH6/EX6.14/Ex6_14.sce b/2510/CH6/EX6.14/Ex6_14.sce new file mode 100755 index 000000000..de7664586 --- /dev/null +++ b/2510/CH6/EX6.14/Ex6_14.sce @@ -0,0 +1,13 @@ +//Variable declaration: +u = 6.72*10**-4 //Viscosity of water (lb/ft.s) +p = 62.4 //Density of water (lb/ft^3) +//For laminar flow: +Re = 2100.0 //Reynolds number +//From table 6.2, we have: +D = 2.067/12.0 //Inside diameter of pipe (ft) + +//Calculation: +V = Re*u/D/p //Average velocity of water flowing (ft/s) + +//Result: +printf("The average velocity of water flowing is: %.2f ft/s.",V) diff --git a/2510/CH6/EX6.2/Ex6_2.sce b/2510/CH6/EX6.2/Ex6_2.sce new file mode 100755 index 000000000..1e54feacd --- /dev/null +++ b/2510/CH6/EX6.2/Ex6_2.sce @@ -0,0 +1,16 @@ +//Variable declaration: +NPS = 3 //Nominal pipe size (inch) +SN = 40 //Schedule number + +//Calculation: +//From Table 6.2, we obtain that the inside diameter of steel pipe is ID = 3.068 in, outside diameter OD = 3.5 in, wal thickness WT = 0.216 in, and pipe weight PW = 7.58 lb/ft. +ID = 3.068 +OD = 3.5 +WT = 0.216 +PW = 7.58 + +//Result: +printf("The inside diameter of steel pipe is : %f in",ID) +printf("The outside diameter of steel pipe is : %f in",OD) +printf("The wall thickness of steel pipe is : %f in",WT) +printf("The weight of steel pipe is : %f lb/ft.",PW) diff --git a/2510/CH6/EX6.3/Ex6_3.sce b/2510/CH6/EX6.3/Ex6_3.sce new file mode 100755 index 000000000..04ee86ff6 --- /dev/null +++ b/2510/CH6/EX6.3/Ex6_3.sce @@ -0,0 +1,14 @@ +//Variable declaration: +ID = 0.957 //Inside diameter of pipe (in) +OD = 1.315 //Outside diameter of pipe (in) +WT = 0.179 //Wall thickness of pipe (in) +PW = 2.17 //Weight of pipe (lb/ft) + +//Calculation: +//From Table 6.2, it indicates that the steel pipe is 1 inch schedule 80. +NSP = 1 +SN = 80 + +//Result: +printf("The nominal size of the pipe is : %f in.",NSP) +printf("The schedule number of the pipe is: %f .",SN) diff --git a/2510/CH6/EX6.4/Ex6_4.sce b/2510/CH6/EX6.4/Ex6_4.sce new file mode 100755 index 000000000..62aa508f7 --- /dev/null +++ b/2510/CH6/EX6.4/Ex6_4.sce @@ -0,0 +1,16 @@ +//Variable declaration: +S = 3/4 //Tube size (in) +BWG = 16 //Birmingham Wire Gauge number (gauge) + +//calculation: +//From table 6.3, we get: +ID = 0.620 //Internal diameter of tube (in) +WT = 0.065 //Wall thickness of tube (in) +OD = ID+2*WT //Outside diameter of tube (in) +EA = 0.1963 //External area per foot (ft) + +//Result: +printf("The inside diameter is : %f in",ID) +printf("The wall thickness is : %f in",WT) +printf("The outside diamater is : %f in",OD) +printf("The external area per foot per foot : %f ft",EA) diff --git a/2510/CH7/EX7.1/Ex7_1.sce b/2510/CH7/EX7.1/Ex7_1.sce new file mode 100755 index 000000000..fbebb4a96 --- /dev/null +++ b/2510/CH7/EX7.1/Ex7_1.sce @@ -0,0 +1,13 @@ +//Variable declaration: +Q = 3000.0 //The rate of heat flow through the glass window (W) +L = 0.01 //Thickness of glass window (m) +A = 3.0 //Area of heat transfer (m^2) +TC = 10+273 //Temperature at the outside surface (K) +k = 1.4 //Thermal onductivity of glass (W/m.K) + +//Calculation: +TH = TC+Q*L/k/A //Temperature at the inner surface (K) + +//Result: +printf("The temperature at the inner surface is : %.1f K",TH) +printf("The temperature at the inner surface is : %.1f °C",TH-273) diff --git a/2510/CH7/EX7.2/Ex7_2.sce b/2510/CH7/EX7.2/Ex7_2.sce new file mode 100755 index 000000000..af8f85bee --- /dev/null +++ b/2510/CH7/EX7.2/Ex7_2.sce @@ -0,0 +1,16 @@ +//Variable declaration: +k = 0.026 //Thermal conductivity of insulating material (Btu/ft.h.°F) +L = 1.0 //Thickness of insulating material (ft) +TC = 70.0 //Temperature on the cold side surface (°F) +TH = 210.0 //Temperature on the hot side surface (°F) +c = 0.252 //Kilocalorie per hour in a Btu per hour +m = 0.093 //meter square in a feet square + +//Calculation: +DT = TH-TC //Change in temperature (°F) +Q1 = k*DT/L //Rate of heat flux throughthe wall (Btu/f^t2.h.) +Q2 = Q1*c/m //Rate of heat flux throughthe wall in SI units (kcal/m^2.h) + +//Result: +printf("The rate of heat flux in Btu/ft^2.h is : %.3f Btu/ft^2.h.",Q1) +printf("The rate of heat flux in SI units is : %.3f kcal/m^2.h.",Q2) diff --git a/2510/CH7/EX7.3/Ex7_3.sce b/2510/CH7/EX7.3/Ex7_3.sce new file mode 100755 index 000000000..f40354bc7 --- /dev/null +++ b/2510/CH7/EX7.3/Ex7_3.sce @@ -0,0 +1,27 @@ +//Variable declaration: +TH = 1592.0 //Temperature of inside surface (K) +TC = 1364.0 //Temperature of outside surface (K) +H = 3.0 //Height of furnace wall (m) +W = 1.2 //Width of furnace wall (m) +L = 0.17 //Thickness furnace wall (m) +m = 0.0929 //Meter square per second in a feet square per second +Btu = 3.412 //Btu per hour in a Watt +Btu2 = 0.3171 //Btu per feet square hour in a watt per meter square + +//Calculation: +Tav = (TH+TC)/2 //Average wall temperature (K) +//From Table in Appendix: +p = 2645.0 //Density of material (kg/m^3) +k = 1.8 //Thermal conductivity (W/m.K) +Cp = 960.0 //Heat capacity of material (J/kg.K) +a = k/(p*Cp)/m //Thermal diffusivity (ft^2/s) +t = (TC-TH)/L //Temperature gradient (°C/m) +A = H*W //Heat transfer area (m^2) +Q1 = k*A*(TH-TC)/L*Btu //Heat transfer rate (Btu/h) +Q2 = k*(TH-TC)/L*Btu2 //Heat transfer flux (Btu/h.ft^2) +R = L/(k*A) //Thermal resistance (°C/W) + +//Result: +printf("The temperature gradient is : %.0f °C/m.",t) +printf("The heat transfer rate is : %.0f Btu/h",Q1) +printf("The heat transfer flux is : %.1f Btu/h.ft^2.",Q2) diff --git a/2510/CH7/EX7.4/Ex7_4.sce b/2510/CH7/EX7.4/Ex7_4.sce new file mode 100755 index 000000000..8e81fbc4c --- /dev/null +++ b/2510/CH7/EX7.4/Ex7_4.sce @@ -0,0 +1,16 @@ +//Variable declaration: +TH = 25.0 //Temperature at inner suface of wall (°C) +TC = -15.0 //Temperature at outer suface of wall (°C) +L = 0.3 //Thickness of wall (m) +k = 1.0 //Thermal conductivity of concrete (W/m) +A = 30.0 //Sueface area of wall (m^2) + +//Calculation: +DT = TH-TC //Driving force for heat transfer (°C) (part 2) +R = L/(k*A) //Thermal resistance (°C/W) (part 3) +Q = DT/R/10**3 //Heat loss through the wall (kW) + +//Result: +printf("1. Theoretical part.") +printf("2. The driving force for heat transfer is : %f °C.",DT) +printf("3. The heat loss through the wall is : %f kW.",Q) diff --git a/2510/CH7/EX7.5/Ex7_5.sce b/2510/CH7/EX7.5/Ex7_5.sce new file mode 100755 index 000000000..a9e344f0c --- /dev/null +++ b/2510/CH7/EX7.5/Ex7_5.sce @@ -0,0 +1,21 @@ +//Variable declaration: +TC = 27.0 //Inside temperature of walls (°C) +TH = 68.7 //Outside temperature of walls (°C) +LC = 6*0.0254 //Thickness of concrete (m) +LB = 8*0.0254 //Thickness of cork-board (m) +LW = 1*0.0254 //Thickness of wood (m) +kC = 0.762 //Thermal conductivity of concrete (W/m.K) +kB = 0.0433 //Thermal conductivity of cork-board (W/m.K) +kW = 0.151 //Thermal conductivity of wood (W/m.K) + +//Calculation: +RC = LC/kC //Thermal resistance of concrete (K/W) +RB = LB/kB //Thermal resistance of cork-board (K/W) +RW = LW/kW //Thermal resistance of wood (K/W) +Q = (TC-TH)/(RC+RB+RW) //Heat transfer rate across the wall (W) +T = -(Q*RW-TC) //Interface temperature between wood and cork-board (K) + +//Result: +printf("The heat transfer rate across the wall is : %.3f W.",Q) +printf("The interface temperature between wood and cork-board is : %.1f °C.",T) +printf("The interface temperature between wood and cork-board is : %.1f K.",T+273) diff --git a/2510/CH7/EX7.6/Ex7_6.sce b/2510/CH7/EX7.6/Ex7_6.sce new file mode 100755 index 000000000..c214f0aff --- /dev/null +++ b/2510/CH7/EX7.6/Ex7_6.sce @@ -0,0 +1,21 @@ +//Variable declaration: +D1s = 4.0 //Glass wool inside diameter (in) +D2s = 8.0 //Glass wool outside diameter (in) +D1a = 3.0 //Asbestos inside diameter (in) +D2a = 4.0 //Asbestos outside diameter (in) +TH = 500.0 //Outer surface temperature of pipe (°F) +TC = 100.0 //Outer surface temperature of glass wool (°F) +La = 0.5/12.0 //Thickness of asbestos (ft) +Lb = 2.0/12.0 //Thickness of glss wool (ft) +ka = 0.120 //Thermal conductivity of asbestos (Btu/h.ft.°F) +kb = 0.0317 //Thermal conductivity of asbestos (Btu/h.ft.°F) +pi = %pi + +//Calculation: +Aa = (pi*(D2a-D1a)/12.0)/log(D2a/D1a) //Area of asbestos (ft^2) +Ab = (pi*(D2s-D1s)/12.0)/log(D2s/D1s) //Area of glass wool (ft^2) +Q1 = (TH-TC)/(La/(ka*Aa)+Lb/(kb*Ab)) //Steady-state heat transfer per foot of pipe (Btu/h.) +Q2 = Q1 +//Result: +printf("The steady-state heat transfer per foot of pipe, Z, is : %.1f x z Btu/h.",Q1) +printf("The steady-state heat transfer factorizating out Z is : %.1f Btu/h.ft.",Q2) diff --git a/2510/CH7/EX7.7/Ex7_7.sce b/2510/CH7/EX7.7/Ex7_7.sce new file mode 100755 index 000000000..11df65174 --- /dev/null +++ b/2510/CH7/EX7.7/Ex7_7.sce @@ -0,0 +1,19 @@ +//Variable declaration: +//From example 7.6: +TH = 500 //Outer surface temperature of pipe (°F) +Lb = 2.0/12.0 //Thickness of glss wool (ft) +kb = 0.0317 //Thermal conductivity of asbestos (Btu/h.ft.°F) +Ab = 1.51 //Area of glass wool (ft^2) +Q = 103.5 //Steady-state heat transfer per foot of pipe (Btu/h.) +La = 0.5/12.0 //Thickness of asbestos (ft) +ka = 0.120 //Thermal conductivity of asbestos (Btu/h.ft.°F) +Aa = 0.91 //Area of asbestos (ft^2) +TC = 100 //Outer surface temperature of glass wool (°F) + +//Calculation: +Ti_b = -((Lb*Q)/(kb*Ab)-TH) //Interfacial temperature of glass wool layer (°F) +Ti_a = (Q*La)/(ka*Aa)+TC //Interfacial temperature of asbestos layer (°F) + +//Result: +printf("The interfacial temperature of glass wool layer is : %.0f °F.",Ti_b) +printf("The interfacial temperature of asbestos layer is : %.1f °F.",Ti_a) diff --git a/2510/CH7/EX7.8/Ex7_8.sce b/2510/CH7/EX7.8/Ex7_8.sce new file mode 100755 index 000000000..f0c8bc476 --- /dev/null +++ b/2510/CH7/EX7.8/Ex7_8.sce @@ -0,0 +1,30 @@ +//Variable declaration: +syms z +syms h +syms k + +pi = %pi + + +T = 100*cos((pi*z)/(2*h)) //Temperature of solid slab + +//Calculation: +DT = diff(T,z) //Temperature at z +Q = -k*(DT) //Heat flux in slab (Btu/s.ft^2) +disp(typeof(Q)) +Q1 = subst(0,z,Q) //Heat flux in slab at z = Btu/s.ft^2) + +Q2 = subst(h,z,Q) //Heat flux in slab at z = h (Btu/s.ft^2) + +//Result: +disp("The heat flux in slab is : ") +disp(Q) +disp("Btu/s.ft^2.") + +disp("The heat flux in slab at z = 0 is : ") +disp(Q1) +disp("Btu/s.ft^2.") + +disp("The heat flux in slab at z = h is :5 ") +disp(Q2) +disp(" Btu/s.ft^2.") diff --git a/2510/CH8/EX8.4/Ex8_4.sce b/2510/CH8/EX8.4/Ex8_4.sce new file mode 100755 index 000000000..d757db43a --- /dev/null +++ b/2510/CH8/EX8.4/Ex8_4.sce @@ -0,0 +1,23 @@ +//Variable declaration: +k = 9.1 //Thermal coductivity of steel rod (Btu/h.ft.°F) +p = 0.29*1728 //Density of steel rod (lb/ft^3) +Cp = 0.12 //Heat capacity of steel rod (Btu/lb.°F) +P = 15+14.7 //Absolute pressure (psia) +Ta = 71.0 //Initial temperature (°F) +L = 20.0/12.0 //Length of rod (ft) +t = 30.0/60.0 //Time taken (h) +x = 0.875/12.0 //Length from one of end (ft) +pi = %pi +e = %e + +//From assumption: +n = 1.0 //First term +//From tables in Appendix: +Ts = 249.7 //Saturated steam temperature (°F) + +//Calculation: +a = k/(p*Cp) //Thermal diffusivity (ft^2/s) +T = Ts+(Ta-Ts)*(((n+1)*(-1)**2 + 1 )/pi)*e**((-a*((n*pi)/L)**2)*t)*sin((n*pi*x)/L) //Temperature 0.875 inches from one of the ends after 30 minutes (°F) + +//Result: +printf ("The temperature 0.875 inches from one of the ends after 30 minutes is : %.0f °F.",T) diff --git a/2510/CH9/EX9.1/Ex9_1.sce b/2510/CH9/EX9.1/Ex9_1.sce new file mode 100755 index 000000000..7f44e52ad --- /dev/null +++ b/2510/CH9/EX9.1/Ex9_1.sce @@ -0,0 +1,15 @@ +//Variable declaration: +D = 1.0 //Diamete of vessel (ft) +L = 1.5 //Length of vessel (ft) +T1 = 390.0 //Surface temperature of vessel (°F) +T2 = 50.0 //Surrounding temperature of vessel (°F) +h = 4.0 //Convective heat transfer coefficient (Btu/h.ft.°F) +pi = %pi + +//Calculation: +A = pi*D*L+2*pi*(D/2)**2 //Total heat transfer area (ft^2) +Q = h*A*(T1-T2) //Rate of heat transfer (Btu/h) +R = 1/(h*A) //Thermal resistance (°F.h/Btu) + +//Result: +printf("The thermal resistance of vessel wal is : %.4f °F.h/Btu.",R) diff --git a/2510/CH9/EX9.10/Ex9_10.sce b/2510/CH9/EX9.10/Ex9_10.sce new file mode 100755 index 000000000..07324c8e2 --- /dev/null +++ b/2510/CH9/EX9.10/Ex9_10.sce @@ -0,0 +1,19 @@ +//Variable declaration: +D = 0.902/12.0 //Inside diameter of tube (ft) +T_in = 60.0 //Temperature water entering the tube (°F) +T_out = 70.0 //Temperature water leaving the tube (°F) +V = 7.0 //Average wave velocity water (ft/s) +p = 62.3 //Density of water (lb/ft^3) +mu = 2.51/3600.0 //Dynamic viscosity of water (lb/ft.s) +Cp = 1.0 //Viscosity of centipoise (Btu/lb.°F) +k = 0.34 //Thermal conductivity of water (Btu/h.ft.°F) + +//Calculation: +Re = D*V*p/mu //Reynolds Number +Pr = Cp*mu/k*3600 //Prandtl number +//From equation 9.26: +Nu = 0.023*(Re**0.8)*(Pr**0.4) //Nusselt number +h = (k/D)*Nu //Average film heat transfer coefficient (Btu/h.ft^2.°F) + +//Result: +printf("The required average film heat transfer coefficient is : %.0f Btu/h.ft^2.°F.",h) diff --git a/2510/CH9/EX9.11/Ex9_11.sce b/2510/CH9/EX9.11/Ex9_11.sce new file mode 100755 index 000000000..b37c3251d --- /dev/null +++ b/2510/CH9/EX9.11/Ex9_11.sce @@ -0,0 +1,21 @@ +//Variable declaration: +P = 1.0132 * 10**5 //Air pressure (Pa) +T = 300.0+273.0 //Air temperature (K) +V = 5.0 //Air flow velocity (m/s) +D = 2.54/100.0 //Diameter of tube (m) +R = 287.0 //Gas constant (m^2/s^2.K) +//From Appendix: +Pr = 0.713 //Prandtl number of nitrogen +mu = 1.784*10**(-5) //Dynamic viscosity of nitrogen (kg/m.s) +k = 0.0262 //Thermal conductivity of nitrogen (W/m.K) +Cp = 1.041 //Heat capacity of nitrogen (kJ/kg.K) + +//Calculation: +p = P/(R*T) //Density of air +Re = D*V*p/mu //Reynolds number +//From table 9.5: +Nu = 0.023*(Re**0.8)*(Pr**0.3) //Nusselt number +h = (k/D)*Nu //Heat transfer coefficient (W/m^2.K) + +//Result: +printf("The required Heat transfer coefficient is : %.2f W/m^2.K.",h) diff --git a/2510/CH9/EX9.12/Ex9_12.sce b/2510/CH9/EX9.12/Ex9_12.sce new file mode 100755 index 000000000..b553e9162 --- /dev/null +++ b/2510/CH9/EX9.12/Ex9_12.sce @@ -0,0 +1,24 @@ +//Variable declaration: +T1 = 15.0 //Water entering temperature (°C) +T2 = 60.0 //Water leaving temperature (°C) +D = 0.022 //Inside diameter of tube (m) +V = 0.355 //Average water flow velocity (m/s) +TC = 150.0 //Outside wall temperature (°C) +//From Appendix: +p = 993.0 //Density of water (kg/m^3) +mu = 0.000683 //Dynamic viscosity of water (kg/m.s) +Cp = 4.17*10**3 //Heat capacity of water (J/kg.K) +k = 0.63 //Thermal conductivity of water (W/m.K) + +//Calculation: +Tav1 = (T1+T2)/2.0 //Average bulk temperature of water (°C) +Re = D*V*p/mu //Reynolds number +Pr = Cp*mu/k //Prandtl number +Tav2 = (Tav1+TC)/2.0 //Fluid's average wall temperature (°C) +//From Appendix: +mu_w = 0.000306 //Dynamic viscosity of fluid at wall (kg/m.s) +//From Table 9.5: +h = (k/D)*0.027*Re**0.8*Pr**0.33*(mu/mu_w)**0.14 //Heat transfer coefficient for water (W/m^2.K) + +//Result: +printf("The heat transfer coefficient for water is : %.1f W/m^2.K.",h) diff --git a/2510/CH9/EX9.13/Ex9_13.sce b/2510/CH9/EX9.13/Ex9_13.sce new file mode 100755 index 000000000..ec9f8f882 --- /dev/null +++ b/2510/CH9/EX9.13/Ex9_13.sce @@ -0,0 +1,11 @@ +//Variable declaration: +//From example 9.7: +h = 38.7 //Average heat transfer coefficient (W/m^2.K) +L = 1.2 //Length of plate (m) +k = 0.025 //Thermal conductivity of air (W/m) + +//Calculation: +Bi = h*L/k //Average Biot number + +//Result: +printf("The average Biot number is : %.0f ",Bi) diff --git a/2510/CH9/EX9.14/Ex9_14.sce b/2510/CH9/EX9.14/Ex9_14.sce new file mode 100755 index 000000000..b66fe45a7 --- /dev/null +++ b/2510/CH9/EX9.14/Ex9_14.sce @@ -0,0 +1,26 @@ +//Variable declaration: +k = 60.0 //Thermal conductivity of rod (W/m.K) +p = 7850.0 //Density of rod (kg/m^3) +Cp = 434.0 //Heat capacity of rod (J/kg.K) +h = 140.0 //Convection heat transfer coefficient (W/m^2.K) +D = 0.01 //Diameter of rod (m) +kf = 0.6 //Thermal conductivity of fluid (W/m.K) +L = 2.5 //Length of rod (m) +Ts = 250.0 //Surface temperature of rod (°C) +Tf = 25.0 //Fluid temperature (°C) + +//Calculation: +//Case 1: +a = k/(p*Cp) //Thermal diffusivity of bare rod (m^2/s) +//Case 2: +Nu = h*D/kf //Nusselt number +//Case 3: +Bi = h*D/k //Biot number of bare rod +//Case 4: +Q = h*(%pi*D*L)*(Ts-Tf) //Heat transferred from rod to fluid (W) + +//Result: +printf("1. The thermal diffusivity of the bare rod is : %.2f x 10^-5 m^2/s.",a/10**-5) +printf("2. The nusselt number is : %.2f .",Nu) +printf("3. The Biot number is : %.4f .",Bi) +printf("4. The heat transferred from the rod to the fluid is : %.0f W.",Q) diff --git a/2510/CH9/EX9.2/Ex9_2.sce b/2510/CH9/EX9.2/Ex9_2.sce new file mode 100755 index 000000000..77b5d1425 --- /dev/null +++ b/2510/CH9/EX9.2/Ex9_2.sce @@ -0,0 +1,14 @@ +//Variable declaration: +//From example 9.1: +R = 0.0398 //Theral resistance (°F.h/Btu) +Btu = 3.412 //Btu/h in a watt +C = 1.8 //Change in degree fahrenheit for a degree change in celsius +K = 1 //Change in degree celsius for a unit change in Kelvin + +//Calculation: +Rc = R*Btu/C //Thermal resistance in degree cesius per watt (°C/W) +Rk = Rc/K //Thermal resistance in Kelvin per watt (K/W) + +//Result: +printf("The thermal resistance in °C/W is : %.3f °C/W.",Rc) +printf("The thermal resistance in K/W is : %.3f K/W.",Rk) diff --git a/2510/CH9/EX9.3/Ex9_3.sce b/2510/CH9/EX9.3/Ex9_3.sce new file mode 100755 index 000000000..9ce1307c9 --- /dev/null +++ b/2510/CH9/EX9.3/Ex9_3.sce @@ -0,0 +1,14 @@ +//Variable declaration: +h = 48.0 //Convective heat transfer coefficient (Btu/h.ft.°F) +A = 2*1.5 //Total heat transfer area (ft^2) +Ts = 530.0 //Surface temperature of plate (°F) +Tm = 105.0 //Maintained temperature of opposite side of plate (°F) +kW = 3.4123*10**3 //Units kW in a Btu/h + +//Calculation: +Q = h*A*(Ts-Tm) //Heat transfer rate in Btu/h (Btu/h) +Q1 = Q/kW //Heat transfer rate in kW (kW) + +//Result: +printf("The heat transfer rate in Btu/h is : %f Btu/h.",Q) +printf("The heat transfer rate in kW is : %.2f kW.",Q1) diff --git a/2510/CH9/EX9.4/Ex9_4.sce b/2510/CH9/EX9.4/Ex9_4.sce new file mode 100755 index 000000000..69a540fab --- /dev/null +++ b/2510/CH9/EX9.4/Ex9_4.sce @@ -0,0 +1,12 @@ +//Variable declaration: +TS = 10+273 //Outer surface temperature of wall (K) +Q = 3000.0 //Heat transfer rate (W) +h = 100.0 //Convection coefficient of air (W/m^2) +A = 3.0 //Area of glass window (m^2) + +//Calculation: +TM = TS-Q/(h*A) //Bulk temperature of fluid (K) + +//Result: +printf("The bulk temperature of fluid is : %f K.",TM) +printf("The bulk temperature of fluid is : %f °C.",TM-273) diff --git a/2510/CH9/EX9.5/Ex9_5.sce b/2510/CH9/EX9.5/Ex9_5.sce new file mode 100755 index 000000000..5103569f0 --- /dev/null +++ b/2510/CH9/EX9.5/Ex9_5.sce @@ -0,0 +1,12 @@ +//Variable declaration: +h = 24.0 //Plant operating hour per day (h/day) +d = 350.0 //Plant operating day per year (day/yr) + +//Calculation: +N = h*d //Operating hours per year (h/yr) +//From example 9.1: +Q = 8545.0 //Rate of energy loss (Btu/h) +Qy = Q*N //Steady-state energy loss yearly (Btu/yr) + +//Result: +printf("The yearly steady-state energy loss is : %.2f x 10^7 Btu/yr.",Qy/10**7) diff --git a/2510/CH9/EX9.7/Ex9_7.sce b/2510/CH9/EX9.7/Ex9_7.sce new file mode 100755 index 000000000..5364b82bb --- /dev/null +++ b/2510/CH9/EX9.7/Ex9_7.sce @@ -0,0 +1,21 @@ + +//Variable declaration: +x = 0.3 //Length from the leading age of the plate (m) +L = 1.2 //Length of plate (m) +TS = 58.0 //Surface temperature of plate (°C) +Ta = 21.0 //Temperature of flowing air (°C) + +//Calculation: +hx = 25/x**0.4 //Local heat transfer coefficient at 0.3m (W/m^2.K) (Part 1) +syms y //Length +hy = 25/y**0.4 //hx at the end of the plate (W/m^2.K) +h = integrate(hy, y,0,L)/L //Average heat transfer coefficient (W/m^2.K) +Q = hx*(TS-Ta) //Heat flux at 0.3m from leading edge of plate (W/m^2) +hL = 25/L**0.4 //Local heat transfer coefficient at plate end (W/m^2.K) (Part 2) +r = h/hL //Ratio h/hL at the end of the plate + +//Result: +printf("1. The heat flux at 0.3 m from the leading edge of the plate is : %.0f W/m^2.",Q) +printf("2. The local heat transfer coefficient at the end of the plate is : %.1f W/m^2.K.",hL) +disp("3. The ratio h/hL at the end of plate is : ") +disp(r) diff --git a/2510/CH9/EX9.8/Ex9_8.sce b/2510/CH9/EX9.8/Ex9_8.sce new file mode 100755 index 000000000..b34740b1f --- /dev/null +++ b/2510/CH9/EX9.8/Ex9_8.sce @@ -0,0 +1,15 @@ +//Variable declaration: +//From example 9.7: +b = 1.0 //Width of plate (m) +L = 1.2 //Length of plate (m) +TS = 58.0 //Surface temperture of plate (°C) +Ta = 21.0 //Air flow temperature (°C) +h = 38.7 //Average heat transfer coefficient (W/m^2.K) + +//Calculation: +A = b*L //Area for heat transfer for the entire plate (m^2) +Q = h*A*(TS-Ta) //Rate of heat transfer over the whole length of the plate (W) +Q = round(Q*10**-1)/10**-1 + +//Result: +printf("The rate of heat transfer over the whole length of the plate is : %.1f W.",Q) diff --git a/2510/CH9/EX9.9/Ex9_9.sce b/2510/CH9/EX9.9/Ex9_9.sce new file mode 100755 index 000000000..b8de3f493 --- /dev/null +++ b/2510/CH9/EX9.9/Ex9_9.sce @@ -0,0 +1,15 @@ +//Variable declaration: +m = 0.075 //Mass rate of air flow (kg/s) +D = 0.225 //Diameter of tube (m) +mu = 208*10**-7 //Dynamic viscosity of fluid (N) +Pr = 0.71 //Prandtl number +k = 0.030 //Thermal conductivity of air (W/m.K) + +//Calculation: +Re = 4*m/(%pi*D*mu) //Reynolds number +//From equation 9.26: +Nu = 0.023*(Re**0.8)*(Pr**0.3) //Nusselt number +h = (k/D)*Nu //Heat transfer coefficient of air (W/m^2.K) + +//Result: +printf("The Heat transfer coefficient of air is : %.2f W/m^2.K.",h) |