Experimental Research and Simulation for the Performance of an R290 Heat Pump with Independent Compression

Since the Kigali Amendment entered into force globally, propane (R290) has been regarded as one of the most promising next-generation alternative refrigerants for refrigeration and air conditioning. However, its flammability limits its maximum charge amount and leads to higher flow resistance loss. In this paper, a novel refrigeration cycle with an additional independent compression process was simulated and experimentally tested. The simulation error of capacity was less than 7.1%. The intermediate evaporation temperature was optimized. The results show that the new cycle delivers stable performance advantages over the conventional R290 heat pump in both cooling and heating modes, with average capacity and COP improvements of 4.8% and 7.8% for cooling, and 8.3% and 7.5% for heating. System flow resistance loss decreases by 33.0%, which raises the refrigerant mass flow rate by 12.5% and reduces the required compressor displacement by 6.6% at equivalent cooling capacity on average.