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Diffstat (limited to '2510/CH15/EX15.14')
| -rwxr-xr-x | 2510/CH15/EX15.14/Ex15_14.sce | 33 |
1 files changed, 33 insertions, 0 deletions
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) |