Inverse defrosting method for air supply heat pump

Abstract

The invention relates to a reverse defrosting method of an air source heat pump. The air source heat pump comprises a controller, a compressor, an evaporator, an expansion valve, a condenser and a circulating pump thereof, and an electric control four-way valve is serially connected between an outlet and an inlet of the compressor. The defrosting method comprises the following steps: the controller controls the electric control four-way valve, the compressor, the evaporator and the circulating pump to act sequentially and perform the following sequential steps repeatedly and alternately: heating, stopping to switch the valves, defrosting, and stopping to switch the valves again; and the reverse defrosting method further comprises the following steps: A) the controller records the time T1 of the heating step in the previous circle and the time t consumed in the subsequent defrosting step; and B) the time T2 of the heating step in the next circle is set after computation according to theoptimum defrosting time b which is obtained by experiments. The air source heat pump can automatically adjust heating operation period, defrosting start time and defrosting time according to the ambient conditions by the reverse defrosting method so as to obtain the optimum energy efficiency ratio.

Description

technical field [0001] The invention relates to a heat pump device, more specifically, the invention relates to a reverse defrosting device of an air source heat pump and a control method thereof. Background technique [0002] When the air source heat pump operates in a low-temperature climate, when the temperature and humidity reach certain conditions, frost will form on the surface of the evaporator. As time goes by, if the frost layer is not removed, the frost will become thicker and thicker, so that it will gradually affect the surface of the evaporator. The heating performance of the heat pump, until it can no longer perform heating work. [0003] Frosting will reduce the heat transfer performance of the evaporator and increase the energy consumption of heating. Therefore, when the frost is formed to a certain extent, it needs to consume extra energy to remove the frost layer of the evaporator, and then resume heating. At present, the common method of traditional rever...

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