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Diffstat (limited to '2510/CH18/EX18.12')
| -rwxr-xr-x | 2510/CH18/EX18.12/Ex18_12.sce | 30 |
1 files changed, 30 insertions, 0 deletions
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) |