Experimental Study on Performance of Flash-tank Vapor Injection Air-Source Heat Pump System with Refrigerant R32

摘要

The flash-tank vapor injection (FTVI) technology was used in screw compressor to solve the problems of high discharge temperature and decline of heating performance of the air source heat pump (ASHP) system in winter. The performance of ASHP system using refrigerant R32 was investigated experimentally. It was found that the relative injection ratio, heating capacity and the power consumption of the compressor increase and the discharge temperature decreases with the increase in the relative injection pressure. For the high ambient temperature, the heating COP of the FTVI system decreases with the increase in the relative injection pressure. While for the low ambient temperature, there is an optimum relative injection pressure, at which the heating COP achieves the maximum. For the heat pump system, the optimum relative injection pressure is observed at about 1.2. The COP of the FTVI heat pump system is higher than that of the conventional ASHP system as the ambient temperature is below -3 °C. Compared with the conventional ASHP system, the discharge temperature of the compressor in the FTVI system is decreased significantly.