Analysis On The Operating Characteristics Of Solar Water Heater In Combination With Air Source Heat Pump Water Heater

Solar water heater cannot supply hot water in cloudy and raining days alone. It in combination with air source heat pump water heater (ASHPWH) is a good choice. The performance of the two kinds of water heater is affected by the water temperature. It is important that the ASHPWH operate at a right temperature of the water. A solar water heater with 4m(2) flat-plate collector assisted by a 1.5kW ASHPWH is studied in this paper. The results show that both the collector efficiency of the solar water heater and the COP of the ASHPWH system decreases as the water temperature increases. The highest and lowest collector efficiency of the solar water heater are 54.4% and 45.6% respectively. The COP of the ASHPWH system ranges from 6.48 to 2.61 as the water temperature increases. Operating sequences of these two kinds of water heater affect solar energy utilization ratio and the power input of the ASHPWH system.