Experimental Research of Air Source Heat Pump Frosting and Defrosting in a Double Stage-Coupling Heat Pump

In a double stage-coupling heat pump, comprising an air source and water loop heat pump, the 13~20 ? low temperature water is supplied to the water loop heat pump unit. The water loop heat pump can extract heat from the water and heat the indoor air. The most common method of air source heat pump frost removal is reverse-cycle defrost. During the defrosting operation, the heat pump runs in the cooling mode. The defrost process is accomplished by reversing the normal heating mode. In this paper, the effect of the heat storage tank to the air source heat pump defrosting is test. Owing to the existence of the heat storage tank, thermal inertia of the loop is relatively high. The frosting and defrosting course of the air source heat pump have little effect on the room temperature