diff options
Diffstat (limited to '3878/CH10/EX10.3/Ex10_3.sce')
-rw-r--r-- | 3878/CH10/EX10.3/Ex10_3.sce | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/3878/CH10/EX10.3/Ex10_3.sce b/3878/CH10/EX10.3/Ex10_3.sce new file mode 100644 index 000000000..97300c638 --- /dev/null +++ b/3878/CH10/EX10.3/Ex10_3.sce @@ -0,0 +1,42 @@ +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) + |