1 files changed, 60 insertions, 0 deletions
diff --git a/2873/CH8/EX8.17/Ex8_17.sce b/2873/CH8/EX8.17/Ex8_17.sce
new file mode 100755
index 000000000..e2c4d36aa
--- /dev/null
+++ b/2873/CH8/EX8.17/Ex8_17.sce
@@ -0,0 +1,60 @@
+// Display mode
+mode(0);
+// Display warning for floating point exception
+ieee(1);
+clear;
+clc;
+disp("Engineering Thermodynamics by Onkar Singh Chapter 8 Example 17")
+P=10*10^3;//output in KW
+disp("from steam tables,h1=3625.3 KJ/s,s1=6.9029 KJ/kg K")
+h1=3625.3;
+s1=6.9029;
+disp("due to isentropic expansion,s1=s2=s3=6.9029 KJ/kg K")
+s2=s1;
+s3=s2;
+disp("at state 2,i.e at pressure of 2 MPa and entropy 6.9029 KJ/kg K")
+disp("by interpolating state for s2 between 2 MPa,300 degree celcius and 2 MPa,350 degree celcius from steam tables,")
+disp("h2=3105.08 KJ/kg ")
+h2=3105.08;
+disp("for state 3,i.e at pressure of 0.01 MPa entropy,s3 lies in wet region as s3<sg at 0.01 MPa.Let dryness fraction be x3 at this state")
+disp("s3=sf at 0.01 MPa+x3*sfg at 0.01 MPa")
+disp("from steam tables,sf at 0.01 MPa=0.6493 KJ/kg K,sfg at 0.01 MPa=7.5009 KJ/kg K")
+sf=0.6493;
+sfg=7.5009;
+disp("so x3=(s3-sf)/sfg")
+x3=(s3-sf)/sfg
+x3=0.834;//approx.
+disp("enthalpy at state 3,h3= hf at 0.01 MPa+x3*hfg at 0.01 MPa in KJ/kg")
+disp("from steam tables,at 0.01 MPa,hf=191.83 KJ/kg,hfg=2392.8 KJ/kg")
+hf=191.83;
+hfg=2392.8;
+h3=hf+x3*hfg
+disp("let the mass of steam bled be mb per kg of steam from exit of HP for regenerative feed heating.")
+disp("Considering state at exit from feed heater being saturated liquid the enthalpy at exit of feed heater will be,hf at 2 MPa")
+disp("h6=hf at 2 MPa=908.79 KJ/kg")
+h6=908.79;
+disp("for adiabatic mixing in feed heater,for one kg of steam leaving boiler,the heat balance yields,")
+disp("(1-mb)*h5+mb*h2=h6")
+disp("while neglecting pump work,")
+disp("h5=h4=hf at 0.01MPa=191.83 KJ/kg")
+h4=191.83;
+h5=h4;
+disp("substituting in heat balance on the feed heater,")
+disp("(1-mb)*h5+mb*h2=h6")
+disp("so mb=(h6-h5)/(h2-h5)in kg per kg of steam entering HP turbine")
+mb=(h6-h5)/(h2-h5)
+mb=0.246;//approx.
+disp("steam bled per kg of steam passing through HP stage=0.246 kg")
+disp("let mass of steam leaving boiler be m kg/s")
+disp("output(P)=m*(h1-h2)+m*(1-mb)*(h2-h3)")
+disp("so m=P/((h1-h2)+(1-mb)*(h2-h3))in kg/s")
+m=P/((h1-h2)+(1-mb)*(h2-h3))
+m=8.25;//approx.
+disp("neglecting pump work,h7=h6=908.79 KJ/kg")
+h7=h6;
+disp("heat supplied to boiler,Q_71=m*(h1-h7) in KJ/s")
+Q_71=m*(h1-h7)
+disp("so heat added=22411.21 KJ/s")
+
+
+