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Diffstat (limited to '572/CH9/EX9.8/c9_8.sce')
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diff --git a/572/CH9/EX9.8/c9_8.sce b/572/CH9/EX9.8/c9_8.sce new file mode 100755 index 000000000..8b643144a --- /dev/null +++ b/572/CH9/EX9.8/c9_8.sce @@ -0,0 +1,53 @@ +//(9.8) Consider a modification of the cycle of Example 9.4 involving reheat and regeneration. Air enters the compressor at 100 kPa, 300 K and is compressed to 1000 kPa. The temperature at the inlet to the first turbine stage is 1400 K. The expansion takes place isentropically in two stages, with reheat to 1400 K between the stages at a constant pressure of 300 kPa. A regenerator having an effectiveness of 100% is also incorporated in the cycle. Determine the thermal efficiency.
+
+
+//solution
+
+//analysis
+//States 1, 2, and 3 are the same as in Example 9.4:
+h1 = 300.19 //in kj/kg
+h2 = 579.9 //in kj/kg
+h3 = 1515.4 //in kj/kg
+//The temperature at state b is the same as at state 3, so
+hb = h3
+
+pa = 300 //in kpa
+p3 = 1000 //in kpa
+//from table A-22
+pr3 = 450.5
+pra = pr3*(pa/p3)
+//Interpolating in Table A-22, we get
+ha = 1095.9 //in kj/kg
+
+p4 = 100 //in kpa
+pb = 300 //in kpa
+prb = pra
+pr4 = prb*(p4/pb)
+//Interpolating in Table A-22, we obtain
+h4 = 1127.6 //in kj/kg
+//Since the regenerator effectiveness is 100%,
+hx = h4
+
+eta = ((h3-ha)+(hb-h4)-(h2-h1))/((h3-hx)+(hb-ha)) //thermal efficiency
+printf('the thermal efficiency is: %f',eta)
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