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Diffstat (limited to '3733/CH22/EX22.27/Ex22_27.sce')
-rw-r--r-- | 3733/CH22/EX22.27/Ex22_27.sce | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/3733/CH22/EX22.27/Ex22_27.sce b/3733/CH22/EX22.27/Ex22_27.sce new file mode 100644 index 000000000..fdad23996 --- /dev/null +++ b/3733/CH22/EX22.27/Ex22_27.sce @@ -0,0 +1,45 @@ +// Example 22_27
+clc;funcprot(0);
+//Given data
+T_1=600;// °C
+p_1=150;// bar
+T_3=600;// °C
+p_3=40;// bar
+p_4=5;// bar
+p_5=0.1;// bar
+
+//Calculation
+//From h-s chart:
+h_1=3570;// kJ/kg
+h_2=3280;// kJ/kg
+h_3=3650;// kJ/kg
+h_4=2920;// kJ/kg
+h_5=2280;// kJ/kg
+// From steam tables
+h_f1=1610;// kJ/kg(at 150 bar)
+h_f2=1087;// kJ/kg(at 40 bar)
+h_f4=640;// kJ/kg(at 5 bar)
+h_f5=192;// kJ/kg(at 0.1 bar)
+function[X]=mass(y)
+ X(1)= (y(1)*(h_2-h_f2))-((1-y(1))*(h_f2-h_f4));
+ X(2)=(y(2)*(h_4-h_f4))-((1-y(1)-y(2))*(h_f4-h_f5));
+endfunction
+y=[0.1 0.1];
+z=fsolve(y,mass);
+m_1=z(1);// kg/kg of steam supplied by the boiler
+m_2=z(2);// kg/kg of steam supplied by the boiler
+W_t=(h_1-h_2)+((1-m_1)*(h_3-h_4))+((1-m_1-m_2)*(h_4-h_5));// Total workdone per kg of steam supplied by the boiler in kJ/kg
+v_w1=1/1000;// m^3/kg
+v_w2=v_w1;// m^3/kg
+v_w3=v_w1;// m^3/kg
+W_p1=(v_w1*(1-m_1-m_2)*(p_4-p_5*10^5))/1000;// kJ/kg
+W_p2=(v_w2*(1-m_1)*(p_1-p_4)*10^5)/1000;// kJ/kg
+W_p3=(v_w3*(m_1)*(p_1-p_3)*10^5)/1000;// kJ/kg
+W_pt=W_p1+W_p2+W_p3;// kJ/kg
+W_n=W_t-W_pt;// Net work done by the turbine per kg of steam supplied by the boiler in kJ
+Q_f=((1-m_1)*h_f1)+(m_1*h_f1);// Heat of feed water entering the boiler in kJ
+Q_s1=h_1-Q_f;// Heat supplied by the boiler per kg of steam in kJ
+Q_s2=(1-m_1)*(h_3-h_2);// Heat supplied in the reheater in kJ/kg
+Q_st=Q_s1+Q_s2;// Total heat supplied in kJ/kg
+n=(W_n/Q_st)*100;// Thermal efficiency in %
+printf('\nm_1=%0.2f kg/kg of steam \nm_2=%0.3f kg/kg of steam \nThermal efficiency=%0.1f percentage',m_1,m_2,n);
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