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+clear
+// Variable declaration
+P_c=10// kW
+T_e=-35// Evaporating temperature in °C
+T_c=40// Condensing temperature in °C
+T_s=5// Subcooling temperature in K
+T_cin=20// Compressor inlet temperature in °C
+T_cout=0// Zero subcooling temperature in °C
+
+// Calculation
+//(a)
+v_s1=146.46// m**3/kg
+v_s2=135.25// m**3/kg
+v_sr=v_s1/v_s2// The ratio of specific volume
+// Assuming the compressor pumps the same volume flowrate:
+m_1bym_2=v_sr// Flow rate ratio
+printf("\n \nFlow rate ratio,m_2/m_1=%1.3f",m_1bym_2)
+
+//(b)
+h_1=392.51// Suction gas enthalpy at 20°C in kJ/kg
+h_2=375.19// Suction gas enthalpy at 0°C in kJ/kg
+h_f=257.77// Liquid enthalpy at the expansion valve inlet at 40°C in kJ/kg
+dh_1=h_1-h_f// Evaporator enthalpy difference at rating condition in kJ/kg
+dh_2=h_2-h_f// Evaporator enthalpy difference with 0°C suction in kJ/kg
+dh_r=dh_2/dh_1// Enthalpy difference ratio
+C_c=P_c*m_1bym_2*dh_r// Compressor capacity corrected for suction temperature change in kW
+printf("\n \nCompressor capacity corrected for suction temperature change=%1.2f kW",C_c)
+
+//(c)
+h_f=249.67// Liquid enthalpy at the expansion valve inlet at 35°C in kJ/kg
+dh=h_2-h_f// Evaporator enthalpy difference at application condition in kJ/kg
+dh_r=dh/dh_1// Enthalpy difference ratio
+C_cact=P_c*m_1bym_2*dh_r// Actual compressor capacity in kW
+printf("\n \nActual compressor capacity=%2.2f kW",C_cact)
+
+//(d)
+h_g=350.13// Suction gas enthalpy at evaporator outlet, -30°C (5 K superheat) in kJ/kg
+dh_e=h_g-h_f// Useful evaporator enthalpy difference in kJ/kg
+dh_r=dh_e/dh_1// Enthalpy difference ratio
+C_eact=P_c*m_1bym_2*dh_r// Actual evaporator capacity in kW
+printf("\n \nActual evaporator capacity=%1.2f kW",C_eact)
+