Experimental Study on Two-Stage Compression Low Temperature Air Source Heat Pump Water heater

摘要

Air source heat pump (ASHP) water heater is equipment for heating water The heat is absorbed from low temperature air source to heat water There are some troubles for single compression heat pump water heater when it is utilized at low temperature air source condition,such as high compression ratio,low efficiency and low heat output etc.A combination of single and two-stage compression heat pump water heater was designed for experiment study at ordinarily or low temperature conditions in this paper The measure instruments and data processing were built up for low temperature air source heat pump water heater The experiments of single and two-stage compression heat pump system in variation conditions are investigated.The results indicated that two-stage ASHP system is more adapted to operate at low environment temperature and that two-stage ASHP system is more efficiency to operate at low environment temperature.The COP of tow-stage ASHP system is higher than that of single-stage ASHP system when environment temperature is below about 5°C,otherwise it is lower than that of single-stage ASHP system.The heat output of two-stage of ASHP system is more than that of single-stage ASHP system.