diff options
Diffstat (limited to '1922/CH4')
28 files changed, 538 insertions, 0 deletions
diff --git a/1922/CH4/EX4.1/4_1.sce b/1922/CH4/EX4.1/4_1.sce new file mode 100755 index 000000000..b64f274c5 --- /dev/null +++ b/1922/CH4/EX4.1/4_1.sce @@ -0,0 +1,14 @@ +clc
+clear
+//Initialization of variables
+T=500 //K
+Qr=5*10^6 //kJ
+T2=600 //K
+//calculations
+dSS=Qr/T
+dSS2=-Qr/T2
+Ds=dSS+dSS2
+//results
+printf("Entropy change of the system = %d kJ/K",dSS)
+printf("\n Entropy change of the surroundings = %d kJ/K",dSS2)
+printf("\n Entropy change if the universe = %d kJ/K",Ds)
diff --git a/1922/CH4/EX4.10/4_10.sce b/1922/CH4/EX4.10/4_10.sce new file mode 100755 index 000000000..66df6020e --- /dev/null +++ b/1922/CH4/EX4.10/4_10.sce @@ -0,0 +1,13 @@ +clc
+clear
+//Initialization of variables
+T1=673 //K
+T2=293 //K
+//calculations
+eta=(T1-T2)/T1
+//results
+if eta>=0.5 then
+ printf("Max efficiency = %.3f and an efficiency of 0.5 is possible",eta)
+else
+ printf("Max efficiency = %.3f and an efficiency of 0.5 is not possible",eta)
+end
diff --git a/1922/CH4/EX4.11/4_11.sce b/1922/CH4/EX4.11/4_11.sce new file mode 100755 index 000000000..28622551c --- /dev/null +++ b/1922/CH4/EX4.11/4_11.sce @@ -0,0 +1,9 @@ +clc
+clear
+//Initialization of variables
+T1=280 //K
+T2=300 //K
+//calculations
+cop=T1/(T2-T1)
+//results
+printf("coefficient of performance = %.1f",cop)
diff --git a/1922/CH4/EX4.12/4_12.sce b/1922/CH4/EX4.12/4_12.sce new file mode 100755 index 000000000..700be6c55 --- /dev/null +++ b/1922/CH4/EX4.12/4_12.sce @@ -0,0 +1,16 @@ +clc
+clear
+//Initialization of variables
+P=2 //Mpa
+T1=212.4+273.1 //K
+T2=25+273.1 //K
+h1=2799.5
+h2=104.89
+s1=6.3409
+s2=0.3674
+//calculations
+dh=h1-h2
+ds=s1-s2
+exergy=dh-T2*ds
+//results
+printf("exergy = %.1f kJ/kg",exergy)
diff --git a/1922/CH4/EX4.13/4_13.sce b/1922/CH4/EX4.13/4_13.sce new file mode 100755 index 000000000..022534886 --- /dev/null +++ b/1922/CH4/EX4.13/4_13.sce @@ -0,0 +1,49 @@ +clc
+clear
+//Initialization of variables
+R=8314.3
+T=700 //K
+T2=437.5 //K
+T3=350 //K
+T4=T3
+p2=0.552 //Mpa
+p1=2.758 //Mpa
+p3=0.345 //Mpa
+cp=29.3
+R0=8.3143
+k=1.4
+n=1
+P0=0.103 //Mpa
+//calculations
+cv=cp-R0
+p3=p2*T3/T2
+p3=0.345
+T5=T4*(p1/p3)^((k-1)/k)
+G1=n*R*T*log(p2/p1)
+V700=R*10^3 *T/(p2*10^9)
+Sa= 209
+Sb=199.2
+Sc=204.7
+S2=(T2-T)/6 *(Sa+4*Sc+Sb )
+G2=V700*(p3-p2)*10^3 -S2
+saa=199.2
+sbb=192.6
+savg=(saa+sbb)*0.5
+G3=-savg*(T3-T2)
+pmid=(p3+p2)/2
+vmid=2.88
+sav=192.7
+v4=8.435 //m^3
+v5=1.911 //m^3
+integ=(p1-p3)*10^3 /6 *(v4+4*vmid+v5)
+G4=integ - sav*(T5-T3)
+Sav=194.25
+G5= -Sav*(T-T5)
+Gt=G1/10^3 +G2+G3+G4+G5
+//results
+printf("in case 1, Change in gibbs free energy = %d kJ",G1/10^3)
+printf("\n in case 2, Change in gibbs free energy = %d kJ",G2)
+printf("\n in case 3, Change in gibbs free energy = %d kJ",G3)
+printf("\n in case 4, Change in gibbs free energy = %d kJ",G4)
+printf("\n in case 5, Change in gibbs free energy = %d kJ",G5)
+printf("\n Net change in gibbs energy = %d kJ",Gt)
diff --git a/1922/CH4/EX4.14/4_14.sce b/1922/CH4/EX4.14/4_14.sce new file mode 100755 index 000000000..9135600c6 --- /dev/null +++ b/1922/CH4/EX4.14/4_14.sce @@ -0,0 +1,23 @@ + +clc +clear +//Initialization of variables +v=1/430 +pi=4.08 //Mpa +pf=10 //Mpa +pf2=1 //Mpa +pii=0.1 //Mpa +R=8314.3 +n=1/28 +T=273.1 +//calculations +logpr=v*(pf-pii)*10^6 /(R*T*n) +pr=exp(logpr) +p=pr*pi +logpr=v*(pf2-pii)*10^6 /(R*T*n) +pr=exp(logpr) +p2=pr*pi +//results +printf("Final pressure = %.2f Mpa",p) +printf("\n Final pressure in case 2 = %.2f Mpa",p2) + diff --git a/1922/CH4/EX4.15/4_15.sce b/1922/CH4/EX4.15/4_15.sce new file mode 100755 index 000000000..25a279598 --- /dev/null +++ b/1922/CH4/EX4.15/4_15.sce @@ -0,0 +1,11 @@ +clc
+clear
+//Initialization of variables
+Hvap=338.14 //kJ/kg
+T=409.3 //K
+//calculations
+dss=Hvap/T
+dg=0
+//results
+printf("change in entropy and gibbs energy of system are %.3f kJ/kg K and %d kJ/kg respectivey",dss,dg)
+printf("\n change in entropy and gibbs energy of universe are %.3f kJ/kg K and %d kJ/kg respectivey",-dss,-dg)
diff --git a/1922/CH4/EX4.16/4_16.sce b/1922/CH4/EX4.16/4_16.sce new file mode 100755 index 000000000..09e4b8a3f --- /dev/null +++ b/1922/CH4/EX4.16/4_16.sce @@ -0,0 +1,18 @@ +clc
+clear
+//Initialization of variables
+T=373.1 //K
+R=8314.3
+Pd=0.1013*10^6 //Pa
+P=10 //Mpa
+p3=5*10^6 //Pa
+vf=0.0373
+a=424.447
+//calculations
+Vd=R*T/Pd
+V=0.5
+dss=-R*(log(p3/Pd) + log((V-vf)/(Vd-vf)))
+dhh=R*T/10^3 - p3/10^3 *V+ a/V^2
+//results
+printf("Change in entropy = %.4f kJ/kmol K",dss/10^3)
+printf("\n change in enthalpy= %d kJ/kmol",dhh)
diff --git a/1922/CH4/EX4.18/4_18.sce b/1922/CH4/EX4.18/4_18.sce new file mode 100755 index 000000000..682bfeefa --- /dev/null +++ b/1922/CH4/EX4.18/4_18.sce @@ -0,0 +1,20 @@ +clc
+clear
+//Initialization of variables
+Tc=647.3 //K
+dh=1.1
+Db=-2
+v2=0.234
+v1=0.27
+//calculations
+dh2=dh+Db*(v2-v1)
+dhh=dh2*Tc
+dhbar=dhh*4.18/18
+disp("From steam tables,")
+h1=3777.5 //kJ/kg
+h2=3928.2 //kJ/kg
+dhs=h2-h1
+err=abs(dhs-dhbar)/dhs
+//results
+printf("Enthalpy departure = %d kJ/kg",dhbar)
+printf("\n Percentage error = %.1f ",err*100)
diff --git a/1922/CH4/EX4.19/4_19.sce b/1922/CH4/EX4.19/4_19.sce new file mode 100755 index 000000000..d2df1d9dd --- /dev/null +++ b/1922/CH4/EX4.19/4_19.sce @@ -0,0 +1,16 @@ +clc
+clear
+//Initialization of variables
+w=0.3448
+R=8.3143
+Tc=647.3
+//calculations
+disp("From charts of entropy")
+h0=0.57
+h1=0.05
+h2=h0+w*h1
+h3=h2*R*Tc
+dh=-h3
+//results
+printf("Enthalpy departure = %d kJ/kmol",dh)
+disp("The answer is a bit different due to rounding off error in the textbook")
diff --git a/1922/CH4/EX4.2/4_2.sce b/1922/CH4/EX4.2/4_2.sce new file mode 100755 index 000000000..edfb04adc --- /dev/null +++ b/1922/CH4/EX4.2/4_2.sce @@ -0,0 +1,29 @@ +clc
+clear
+//Initialization of variables
+p1=2.758 //Mpa
+p2=0.552 //Mpa
+T1=700 //K
+T2=700 //K
+n=1
+R=8.3143
+Cv=21
+Cp=29.3
+//calculations
+dsa=n*R*log(p1/p2)
+T3=437.5 //K
+dsb=Cv*log(T3/T2)
+T4=350 //K
+dsc=Cp*log(T4/T3)
+T5=634 //K
+dsd=0
+T6=700 //K
+dse=Cp*log(T6/T5)
+dstotal=dsa+dsb+dsc+dsd+dse
+//results
+printf("Entropy change in case a = %.3f kJ/kmol K",dsa)
+printf("\n Entropy change in case b = %.3f kJ/kmol K",dsb)
+printf("\n Entropy change in case c = %.3f kJ/kmol K",dsc)
+printf("\n Entropy change in case d = %.3f kJ/kmol K",dsd)
+printf("\n Entropy change in case e = %.3f kJ/kmol K",dse)
+printf("\n Entropy change in total process = %.3f kJ/kmol K",dstotal)
diff --git a/1922/CH4/EX4.20/4_20.sce b/1922/CH4/EX4.20/4_20.sce new file mode 100755 index 000000000..09d1deb29 --- /dev/null +++ b/1922/CH4/EX4.20/4_20.sce @@ -0,0 +1,48 @@ +clc
+clear
+//Initialization of variables
+ta=310 //K
+pa=80 //kPa
+r=10
+k=1.4
+R=8.3143
+n=5/29
+cv=20.93
+//calculations
+Qab=0
+tb=ta*r^(k-1)
+va=R*ta/pa
+vb=va/r
+pb=R*tb/vb
+Wab= -n*R*ta/(k-1) *((pb/pa)^((k-1)/k) -1)
+vc=vb
+Qbc=500 //kJ
+Wbc=0
+tc=tb+ Qbc/(n*cv)
+pc=R*tc/vc
+Qcd=0
+td=tc/r^(k-1)
+vd=va
+pd=td/tc*(vc/vd)*pc
+Wcd=-n*R*tc/(k-1) *((pd/pc)^((k-1)/k)-1)
+Wda=0
+Qda=n*cv*(ta-td)
+eta0=1-1/r^(k-1)
+//results
+printf("Efficiency of cycle = %.3f",eta0)
+p=[pa pb pc pd]
+t=[ta tb tc td]
+Q=[Qab Qbc Qcd Qda]
+W=[Wab Wbc Wcd Wda]
+disp('Pressure (kPa) = ')
+format('v',6);p
+disp(p)
+disp("Temperature (K)= ")
+format('v',6);t
+disp(t)
+disp("Heat (kJ)= ")
+format('v',6);Q
+disp(Q)
+disp("Work done (kJ) = ")
+format('v',6);W
+disp(W)
diff --git a/1922/CH4/EX4.21/4_21.sce b/1922/CH4/EX4.21/4_21.sce new file mode 100755 index 000000000..44fd7445c --- /dev/null +++ b/1922/CH4/EX4.21/4_21.sce @@ -0,0 +1,16 @@ +clc
+clear
+//Initialization of variables
+ta=310 //K
+tc=917.3 //K
+td=365.2 //K
+n=0.602
+k=1.4
+//calculations
+lntb= 1/(1-n)/k
+tb=tc- lntb*(td-ta)
+rc=(tb/ta)^(1/(k-1))
+//results
+printf("Temperature at B = %.1f K",tb)
+printf("\n Compression ratio = %d ",rc)
+disp("The answer given in textbook for rc is wrong. please check using a calculator")
diff --git a/1922/CH4/EX4.22/4_22.sce b/1922/CH4/EX4.22/4_22.sce new file mode 100755 index 000000000..053f6233b --- /dev/null +++ b/1922/CH4/EX4.22/4_22.sce @@ -0,0 +1,27 @@ +clc
+clear
+//Initialization of variables
+pr=4
+k=1.4
+ta=298 //K
+pa=0.1 //Mpa
+pdr=0.01
+tc=900 //K
+pri=0.005 //Mpa
+//calculations
+pb=pr*pa
+nji=1- (pr)^((1-k)/k)
+tb=ta*(pb/pa)^((k-1)/k)
+pc=pb-pdr
+pd=pa+pri
+td=tc*(pd/pc)^((k-1)/k)
+//results
+p=[pa pb pc pd]
+t=[ta tb tc td]
+printf("ideal thermal efficiency = %.3f ",nji)
+disp("pressure (Mpa) = ")
+format('v',6);p
+disp(p)
+disp("temperature (K) = ")
+format('v',6);t
+disp(t)
diff --git a/1922/CH4/EX4.23.a/4_23a.sce b/1922/CH4/EX4.23.a/4_23a.sce new file mode 100755 index 000000000..bf5be917a --- /dev/null +++ b/1922/CH4/EX4.23.a/4_23a.sce @@ -0,0 +1,15 @@ +clc
+clear
+//Initialization of variables
+sd=4.9269//kJ/kg/K
+sf=1.1453//kJ/kg/K
+sg=7.5320//kJ/kg/K
+hf=359.86//kJ/kg
+hg=2653.5//kJ/kg
+hd=2409.7//kJ/kg
+//calculations
+x=(sd-sg)/(sf-sg)
+he=x*hf+(1-x)*hg
+etar=(hd-he)/(hd-hf)
+//results
+printf("Thermal efficiency = %.4f",etar)
diff --git a/1922/CH4/EX4.23.b/4_23b.sce b/1922/CH4/EX4.23.b/4_23b.sce new file mode 100755 index 000000000..0b9d06227 --- /dev/null +++ b/1922/CH4/EX4.23.b/4_23b.sce @@ -0,0 +1,16 @@ +clc
+clear
+//Initialization of variables
+sd=6.7039//kJ/kg/K
+sf=1.1453//kJ/kg/K
+sg=7.5320//kJ/kg/K
+hf=359.86//kJ/kg
+hg=2653.5//kJ/kg
+hd=3717.9//kJ/kg
+//calculations
+x=(sd-sg)/(sf-sg)
+he=x*hf+(1-x)*hg
+etar=(hd-he)/(hd-hf)
+//results
+printf("Thermal efficiency = %.4f",etar)
+
diff --git a/1922/CH4/EX4.24/4_24.sce b/1922/CH4/EX4.24/4_24.sce new file mode 100755 index 000000000..3433339f2 --- /dev/null +++ b/1922/CH4/EX4.24/4_24.sce @@ -0,0 +1,9 @@ +clc
+clear
+//Initialization of variables
+ha=2510.6 //kJ/kg
+hd=125.78 //kJ/kg
+//calculations
+kg=(10^6)/(ha-hd)
+//results
+printf("circulation rate = %d kg steam/h",kg)
diff --git a/1922/CH4/EX4.25/4_25.sce b/1922/CH4/EX4.25/4_25.sce new file mode 100755 index 000000000..9f45f0776 --- /dev/null +++ b/1922/CH4/EX4.25/4_25.sce @@ -0,0 +1,14 @@ +clc
+clear
+//Initialization of variables
+tin=298 //K
+tout=273 //K
+tout2=308 //K
+tin2=294 //K
+//calculations
+eta1=(tin-tout)/tin
+eta2=abs((tin2-tout2)/tin2)
+//results
+printf("Efficiency in case 1 = %.3f",eta1)
+printf("\n efficiency in case 2 = %.3f",eta2)
+
diff --git a/1922/CH4/EX4.26/4_26.sce b/1922/CH4/EX4.26/4_26.sce new file mode 100755 index 000000000..7a925027e --- /dev/null +++ b/1922/CH4/EX4.26/4_26.sce @@ -0,0 +1,20 @@ +clc
+clear
+//Initialization of variables
+ma=500 //kg/h
+cp1=3.2 //kJ/kg K
+ta=20 //C
+mb=200
+mc=300 //kg/h
+cp2=2.8 //kJ/kg K
+tc=80 //C
+tb=80 //C
+me=50 //kg/h
+te=120 //C
+td=120 //C
+hg=503.7
+he=2706.3
+//calcualtions
+Ws=(mb+me)*hg + mc*cp2*(tc) - me*he -ma*cp1*(ta)
+//results
+printf("Net work done = %d kJ/h",Ws)
diff --git a/1922/CH4/EX4.27/4_27.sce b/1922/CH4/EX4.27/4_27.sce new file mode 100755 index 000000000..255be1c8b --- /dev/null +++ b/1922/CH4/EX4.27/4_27.sce @@ -0,0 +1,10 @@ +clc
+clear
+//Initialization of variables
+hc=150 //Btu/lb
+he=-115 //Btu/lb
+hg=168 //Btu/lb
+//calculations
+frac=(hg-hc)/(hg-he)
+//results
+printf("Fraction of solid = %.3f",frac)
diff --git a/1922/CH4/EX4.28/4_28.sce b/1922/CH4/EX4.28/4_28.sce new file mode 100755 index 000000000..1baeea87d --- /dev/null +++ b/1922/CH4/EX4.28/4_28.sce @@ -0,0 +1,12 @@ +clc
+clear
+//Initialization of variables
+H=2696.5 //kJ/kg
+hg=2706.7 //kJ/kg
+hf=504.7 //kJ/kg
+//calculations
+x= (H-hf)/(hg-hf)
+x2=1
+//results
+printf("In case 1, fraction of vapor = %.3f",x)
+printf("\n In case 2, fraction of vapor = %.3f",x2)
diff --git a/1922/CH4/EX4.3/4_3.sce b/1922/CH4/EX4.3/4_3.sce new file mode 100755 index 000000000..cc9151fa2 --- /dev/null +++ b/1922/CH4/EX4.3/4_3.sce @@ -0,0 +1,15 @@ + +clc +clear +//Initialization of variables +ratio=1/2 +R=8.314 +p1=0.5 //kPa +p2=0.1 //kPa +//calculations +ya=ratio/(1+ratio) +ds=-ya*R*log(ya) - (1-ya)*R*log(1-ya) +dss=R*log(p1/p2) +//results +printf("Entropy of mixing = %.3f kJ/kmol K",ds) +printf("\n Total entropy change of the universe = %.2f kJ/kmol K",dss) diff --git a/1922/CH4/EX4.4/4_4.sce b/1922/CH4/EX4.4/4_4.sce new file mode 100755 index 000000000..c8cc85967 --- /dev/null +++ b/1922/CH4/EX4.4/4_4.sce @@ -0,0 +1,22 @@ +clc
+clear
+//Initialization of variables
+s1=7.096 //kJ/kg K
+s2=7.915 //kJ/kg K
+s3=7.16 //kJ/kg K
+s4=7.014 //kJ/kg K
+s5=6.999 //kJ/kg K
+//calculations
+dsa=s2-s1
+dsb=s3-s2
+dsc=s4-s3
+dsd=s5-s4
+dse=s1-s5
+dstotal=dsa+dsb+dsc+dsd+dse
+//results
+printf("Change in entropy in process a =%.3f kJ/kg K",dsa)
+printf("\n Change in entropy in process b =%.3f kJ/kg K",dsb)
+printf("\n Change in entropy in process c =%.3f kJ/kg K",dsc)
+printf("\n Change in entropy in process d =%.3f kJ/kg K",dsd)
+printf("\n Change in entropy in process e =%.3f kJ/kg K",dse)
+printf("\n Change in entropy in total process =%.3f kJ/kg K",dstotal)
diff --git a/1922/CH4/EX4.5/4_5.sce b/1922/CH4/EX4.5/4_5.sce new file mode 100755 index 000000000..6bffcfe99 --- /dev/null +++ b/1922/CH4/EX4.5/4_5.sce @@ -0,0 +1,15 @@ +clc
+clear
+//Initialization of variables
+m1=5000 //kg/h
+cp1=3.2 //kJ/kg K
+cp2=4.186 //kJ/kg K
+t1=220 //C
+t2=30 //C
+T1=210 //C
+T2=20 //C
+//calculations
+m2=m1*cp1*(t1-t2)/(cp2*(T1-T2))
+ds=m1*cp1*log((t2+273.1)/(t1+273.1)) + m2*cp2*log((T1+273.1)/(T2+273.1))
+//results
+printf("Change in entropy = %d kJ/h K",ds)
diff --git a/1922/CH4/EX4.6/4_6.sce b/1922/CH4/EX4.6/4_6.sce new file mode 100755 index 000000000..a917aa73c --- /dev/null +++ b/1922/CH4/EX4.6/4_6.sce @@ -0,0 +1,12 @@ + +clc +clear +//Initialization of variables +s1=218.8 //kJ/kmol K +s2=188.85 //kJ/kmol K +s3=237.8 //kJ/kmol K +s4=205.2 //kJ/kmol K +//calculations +ds=s1+s2-s3-0.5*s4 +//results +printf("Entropy change = %.2f kJ/kmol K",ds) diff --git a/1922/CH4/EX4.7/4_7.sce b/1922/CH4/EX4.7/4_7.sce new file mode 100755 index 000000000..a4a3c8192 --- /dev/null +++ b/1922/CH4/EX4.7/4_7.sce @@ -0,0 +1,24 @@ +clc
+clear
+//Initialization of variables
+Q=6 //kJ/kg
+p1=1.5 //Mpa
+p2=0.1 //Mpa
+t1=500 //C
+t2=140.8 //C
+h1=3473.1 //kJ
+h2=2758.1 //kJ
+s1=7.5698 //kJ/K
+s2=7.5698 //kJ/K
+eff=0.85
+Ts=293.1 //K
+//calculations
+Wideal=h2-h1
+Ws=eff*Wideal
+dH=-Q-Ws
+H2=h1+dH
+S2=7.8005
+ds=S2-s1
+Wlost=Ts*ds+Q
+//results
+printf("lost work = %.1f kJ",Wlost)
diff --git a/1922/CH4/EX4.8/4_8.sce b/1922/CH4/EX4.8/4_8.sce new file mode 100755 index 000000000..c36e97bc1 --- /dev/null +++ b/1922/CH4/EX4.8/4_8.sce @@ -0,0 +1,17 @@ +clc
+clear
+//Initialization of variables
+m=5000 ///kg/h
+cp=3.2 //kJ/kg K
+Ts=30+273.1 //K
+t1=220 //C
+t2=40 //C
+Q=2.88*10^6 //kJ
+//calculations
+Q=m*cp*(t2-t1)
+dss=m*cp*log((t2+273.1)/(t1+273.1))
+Wlost=Ts*dss-Q
+eff=Ts*dss/Q
+//results
+printf("Lost work = %d kJ",Wlost)
+printf("\n Efficiency = %.3f",eff)
diff --git a/1922/CH4/EX4.9/4_9.sce b/1922/CH4/EX4.9/4_9.sce new file mode 100755 index 000000000..7fed8f217 --- /dev/null +++ b/1922/CH4/EX4.9/4_9.sce @@ -0,0 +1,28 @@ +clc
+clear
+//Initialization of variables
+R=8.314
+cp=35.58
+n=100/16
+T1=300 //K
+T2=500 //K
+k=1.305
+P2=3 //Mpa
+P1=0.5 //Mpa
+Ts=290 //K
+//calculations
+cv=cp-R
+Wi=n*R*T1/(k-1) *((P2/P1)^((k-1)/k) -1)
+Hi=Wi
+Ha=n*cp*(T2-T1)
+eta=abs(Hi/Ha)
+dss1=cp*log(T2/T1) - R*log(P2/P1)
+Wl1=Ts*dss1
+dss2=n*cp*log(T2/T1)
+dss3=abs(Ha/Ts)
+dsst=dss2+dss3
+Wl2=-Ts*dss2 +Ha
+Wlost=Wl1+Wl2
+//results
+printf("Thermodynamic efficiency = %.3f",eta)
+printf("\n Net work lost = %d kJ",Wlost)
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