Study on quasi two-stage compression cycle characteristics of the water heater of the air source heat pump in cold area

The water heater of an air source heat pump has the disadvantages of high exhaust temperature and weak heating performance in a cold area. The quasi two-stage compression cycle technology can effectively improve its operation characteristics in the cold area. In this paper, a rotor compressor with a medium pressure air supply is used to develop the water heater with R410A as the circulating working fluid. The system's heating performance under low temperature environments is experimentally studied. The results show that the exhaust temperature of the water heater system with the medium pressure air supply is lower than those without the air-supply system.