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Diffstat (limited to '3831/CH10/EX10.15/Ex10_15.sce')
-rw-r--r-- | 3831/CH10/EX10.15/Ex10_15.sce | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/3831/CH10/EX10.15/Ex10_15.sce b/3831/CH10/EX10.15/Ex10_15.sce new file mode 100644 index 000000000..bdf39775a --- /dev/null +++ b/3831/CH10/EX10.15/Ex10_15.sce @@ -0,0 +1,31 @@ +// Example 10_15
+clc;funcprot(0);
+// Given data
+m_air=0.800;// kg/s
+T_air_in=20.0;// °C
+T_0=20.0;// °C
+p_ein=1.10;// atm
+p_eout=1.0;// atm
+p_ain=1.50;// atm
+p_aout=1.40;// atm
+p_0=1.00;// atm
+T_ein=500;// °C
+T_eout=400;// °C
+c_p_exh=0.990;// kJ/(kg.K)
+c_p_air=1.004;// kJ/(kg.K)
+m_exh=m_air;// kg/s
+m_cold=m_air;// kg/s
+R_exh=0.272;// kJ/(kg.K)
+R_air=0.286;// kJ/(kg.K)
+
+// Calculation
+// (a)
+c_p_cold=c_p_air;// kJ/(kg.K)
+T_air_out=T_air_in+(((m_exh*c_p_exh)/(m_cold*c_p_cold))*(T_ein-T_eout));// °C
+// (b)
+a_f_inexh=(c_p_exh*(T_ein-T_0))-((T_0+273.15)*[(c_p_exh*log((T_ein+273.15)/(T_0+273.15)))-(R_exh*log(p_ein/p_0))])+0+0;// kJ/kg
+a_f_outexh=(c_p_exh*(T_eout-T_0))-((T_0+273.15)*[(c_p_exh*log((T_eout+273.15)/(T_0+273.15)))-(R_exh*log(p_eout/p_0))])+0+0;// kJ/kg
+a_f_inair=(c_p_air*(T_air_in-T_0))-((T_0+273.15)*[(c_p_air*log((T_air_in+273.15)/(T_0+273.15)))-(R_air*log(p_ain/p_0))])+0+0;// kJ/kg
+a_f_outair=(c_p_air*(T_air_out-T_0))-((T_0+273.15)*[(c_p_air*log((T_air_out+273.15)/(T_0+273.15)))-(R_air*log(p_aout/p_0))])+0+0;// kJ/kg
+E_nmHX=((m_air*(a_f_outair-a_f_inair))/(m_exh*(a_f_inexh-a_f_outexh)))*100;// The second law availability efficiency in %
+printf("\n(a)The exit temperature of the inlet air,(T_out)_air=%3.0f°C \n(b)The second law availability efficiency of the preheater,E_nonmixingHX=%2.1f percentage",T_air_out,E_nmHX);
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