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Diffstat (limited to '3831/CH14/EX14.3/Ex14_3.sce')
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diff --git a/3831/CH14/EX14.3/Ex14_3.sce b/3831/CH14/EX14.3/Ex14_3.sce new file mode 100644 index 000000000..fb994c0b5 --- /dev/null +++ b/3831/CH14/EX14.3/Ex14_3.sce @@ -0,0 +1,60 @@ +// Example 14_3
+clc;funcprot(0);
+// Given data
+T_H=20.0+273.15;// K
+T_L=-15.0+273.15;// K
+
+// Solution
+// (a)
+COP_Cr=T_L/(T_H-T_L);// COP of a reversed Carnot cycle
+// From Table C.9b in Thermodynamic Tables to accompany Modern Engineering Thermodynamics, the thermodynamic data at the monitoring stations shown in the schematic are
+// Station 1
+T_1=-15.0;// °C
+s_1=0.89973;// kJ/(kg.K)
+s_2s=s_1;// kJ/(kg.K)
+x_1=0.9395;// The quality of steam
+h_1=231.0;// kJ/kg
+s_f1=0.11075;// kJ/(kg.K)
+s_fg1=0.83977;// kJ/(kg.K)
+h_f1=27.33;// kJ/kg
+h_fg1=216.79;// kJ/kg
+// Station 2
+T_2s=20.0;// °C
+x_2s=1.00;// The quality of steam
+h_2s=256.5;// kJ/kg
+s_2s=0.89973;// kJ/(kg.K)
+p_2s=909.9;// kPa
+// Station 3
+T_3=20.0;// °C
+x_3=0.00;// The quality of steam
+h_3=68.67;// kJ/kg
+s_3=0.25899;// kJ/(kg.K)
+p_3=p_2s;// kPa
+// Station 4
+T_4s=T_1;// °C
+s_4s=s_3;// kJ/(kg.K)
+x_4s=0.1765;// The quality of steam
+h_4s=65.6;// kJ/kg
+s_f4=0.11075;// kJ/(kg.K)
+s_fg4=0.83977;// kJ/(kg.K)
+h_f4=h_f1;// kJ/kg
+h_fg4=h_fg1;// kJ/kg
+x_1=(s_2s-s_f1)/s_fg1;
+h_1=h_f1+(x_1*h_fg1);// kJ/kg
+// where we have calculated
+x_4s=(s_3-s_f4)/s_fg4;// The quality of steam
+h_4s=h_f4+(x_4s*h_fg4);// kJ/kg
+Q_L=h_1-h_4s;// kJ/kg
+W_c=h_2s-h_1;// kJ/kg
+W_t=h_3-h_4s;// kJ/kg
+COP_et=Q_L/(W_c-W_t);// COP for isentropic vapour compressor cycle with expansion turbine
+// (c)
+// Station 4h
+T_4h=T_1;// °C
+h_4h=h_3;// kJ/kg
+x_4h=(h_4h-h_f4)/h_fg4;// The quality of steam
+s_4h=s_f4+(x_4h*s_fg4);// kJ/(kg.K)
+Q_L=h_1-h_4h;// kJ/kg
+W_c=h_2s-h_1;// kJ/kg
+COP_tv=Q_L/W_c;// COP for isentropic vapor-compression cycle with throttling valve
+printf("\n(a)COP_carnot refrigerator=%1.2f \n(b)COP_isentropic vapour compressor cycle with expansion turbine=%1.2f \n(c)COP_isentropic vapor-compression cycle with throttling valve=%1.2f",COP_Cr,COP_et,COP_tv);
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