Experimental Study on Heating Performance of Air - source Heat Pump with Water Tank for Thermal Energy Storage

Abstract Through the experiment, the coefficient of performance (COP) of air source heat pump with changing water temperature in the tank was studied, when the ambient temperature remains almost unchanged. Then the COPs of the air source heat pump at different supply and return water temperatures were calculated out based on the tested model.The results showed that COP equals 3.1, when the supply/return? water temperature was 21℃, and it would decrease by 0.04 with every 1℃ temperature dropping; when the water temperature reached 55℃, COP stood at only 0.74, and the water temperature rose 1℃, COP reduced 0.12. For the supply and return water of 50℃ / 40℃ compared to that of 50℃ / 45℃, COP increased by 10.3%; similarly, for 45℃ / 40℃ compared to 50℃ / 40℃, COP increased by 12.9%. The system COP decreased with increasing supply and return water temperatures, and the rate of reduction was affected by the heat loss of the piping system.