the condenser outlet temperature ranges from 25°C to 50°C, the FE inlet temperature
varies from -35°C to -20°C, the R290/R600a mixture is in the composition range of
0.3–0.7 mass fraction of propane; the superheating degrees in two evaporators are
assumed to be zero, but the subcooling degrees in SHLX-I and SHLX-II of the cycle
are set at Dt4,5=25°C and 4',5'Dt =25°C; the quality of mixture refrigerant at the outlet
of condenser-I is set at 3x =0.5 ;