// Display mode mode(0); // Display warning for floating point exception ieee(1); clear; clc; disp("Engineering Thermodynamics by Onkar Singh Chapter 8 Example 7") disp("from steam tables,") disp("h2=h at 50 bar,500oc=3433.8 KJ/kg,s2=s at 50 bar,500oc=6.9759 KJ/kg K") h2=3433.8; s2=6.9759; disp("s3=s2=6.9759 KJ/kg K") s3=s2; disp("by interpolation from steam tables,") disp("T3=183.14oc at 5 bar,h3=2818.03 KJ/kg,h4= h at 5 bar,400oc=3271.9 KJ/kg,s4= s at 5 bar,400oc=7.7938 KJ/kg K") T3=183.14; h3=2818.03; h4=3271.9; s4=7.7938; disp("for expansion process 4-5,s4=s5=7.7938 KJ/kg K") s5=s4; disp("let dryness fraction at state 5 be x5") disp("s5=sf at 0.05 bar+x5*sfg at 0.05 bar") disp("from steam tables,at 0.05 bar,sf=0.4764 KJ/kg K,sfg=7.9187 KJ/kg K") sf=0.4764; sfg=7.9187; disp("so x5=(s5-sf)/sfg") x5=(s5-sf)/sfg x5=0.924;//approx. disp("h5=hf at 0.05 bar+x5*hfg at 0.05 bar in KJ/kg") disp("from steam tables,hf at 0.05 bar=137.82 KJ/kg,hfg at 0.05 bar=2423.7 KJ/kg") hf=137.82; hfg=2423.7; h5=hf+x5*hfg disp("h6=hf at 0.05 bar=137.82 KJ/kg") h6=137.82; disp("v6=vf at 0.05 bar=0.001005 m^3/kg") v6=0.001005; disp("for process 6-1 in feed pump,h1=h6+v6*(p1-p6) in KJ/kg") p1=50;//steam generation pressure in bar p6=0.05;//steam entering temperature in turbine in bar h1=h6+v6*(p1-p6)*100 disp("cycle efficiency=W_net/Q_add") disp("Wt=(h2-h3)+(h4-h5) in KJ/kg") Wt=(h2-h3)+(h4-h5) disp("W_pump=(h1-h6)in KJ/kg") W_pump=(h1-h6) disp("W_net=Wt-W_pump in KJ/kg") W_net=Wt-W_pump disp("Q_add=(h2-h1) in KJ/kg") Q_add=(h2-h1) disp("cycle efficiency=") W_net/Q_add disp("in percentage") W_net*100/Q_add disp("we know ,1 hp=0.7457 KW") disp("specific steam consumption=0.7457*3600/W_net in kg/hp hr") 0.7457*3600/W_net disp("work ratio=net work/positive work=W_net/Wt") W_net/Wt disp("so cycle efficiency=45.74%,specific steam consumption =1.78 kg/hp hr,work ratio=0.9967")