Thermodynamic Analysis of a Modified Air Source High Temperature Heat Pump

This paper proposes a modified air source high temperature heat pump cycle (EIHP) with a heat sink temperature of 80∼100◦, in which the zeotropic mixture R290/R600a is applied. In EIHP system, the internal auto-cascade technique and an ejector are used to enhance the system performance. Performance of EIHP is investigated by using a developed thermodynamic model. According to the simulation results, compared with the conventional heat pump cycle (CHP), as the evaporator outlet temperature ranges from 25℃ to -10℃, EIHP yields 15%∼27% higher COP, 20%∼46% lower compression ratio and 22%∼51% higher volumetric heating capacity at a fixed condenser outlet temperature of 100℃. Moreover, in order to evaluated the system performances in detail, the other critical parameters are investigated in this study including condenser outlet temperature, refrigerant mass composition and so on.