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Diffstat (limited to '3685/CH12/EX12.7/Ex12_7.sce')
| -rw-r--r-- | 3685/CH12/EX12.7/Ex12_7.sce | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/3685/CH12/EX12.7/Ex12_7.sce b/3685/CH12/EX12.7/Ex12_7.sce new file mode 100644 index 000000000..a12c3be96 --- /dev/null +++ b/3685/CH12/EX12.7/Ex12_7.sce @@ -0,0 +1,34 @@ +clc +Ti = 2000 // Hot gas inlet temperature in K +Te = 450 // Hot gas exhaust temperature in K +T0 = 300 // Ambient temperature in K +Q1_dot = 100 // Heating rate provided by steam in kW +cpg = 1.1 // Heat capacity of gas in kJ/kg +wg = Q1_dot/(cpg*(Ti-Te)) // mass flow rate of hot gas +af1 = wg*cpg*T0*((Ti/T0)-1-log(Ti/T0)) // Availability at inlet +af2 = wg*cpg*T0*((Te/T0)-1-log(Te/T0)) // Availability at exit +afi = af1-af2 // Change in availability +h1 = 2801 // Enthalpy at state 1 in kJ/kg +h3 = 169 //Enthalpy at state 3 in kJ/kg +h4 = 172.8 //Enthalpy at state 4 in kJ/kg +h2 = 1890.2 // Enthalpy at state 2 in kJ/kg +s1 = 6.068 // Entropy at state 1 in kJ/kgK +s2 = s1 // Isentropic process +s3 = 0.576 // Entropy at state 3 in kJ/kgK +s4 = s3 // Isentropic process +Wt = h1-h2 // Turbine work +Wp = h4-h3 // Pump work +Q1 = h1-h4 // Heat addition +Q2 = h2-h3// Heat rejection +Wnet = Wt-Wp // Net work +ws = Q1_dot/2628 // steam mass flow rate +afu = 38*(h1-h4-T0*(s1-s3)) // availability loss +I_dot = afi-afu // Rate of exergy destruction +Wnet_dot = ws*Wnet// Mechanical power rate +afc = ws*(h2-h3-T0*(s2-s3)) // Exergy flow rate of of wet steam +n2 = 100*Wnet_dot/af1 // second law efficiency + +printf("\n Example 12.7\n") +printf("\n The second law efficiency is %f percent",n2) +//The answers vary due to round off error + |