Heat pump water heater and its defrosting control method and device

Abstract

The invention discloses a heat pump water heater and a defrosting control method and device thereof. The method comprises the following steps that when the heat pump water heater enters a defrosting mode, the system pressure, generated during defrosting of previous N times, of the heat pump water heater or the work current of a compressor in the heat pump water heater is obtained, and the quitted defrosting coiler temperature during defrosting of last time is obtained; the change trend of the system pressure of defrosting of the previous N times is judged or the change trend of the work current of the compressor during defrosting of the previous N times is judged; and the quitted defrosting coiler temperature of the heat pump water heater during defrosting of last time is corrected according to the change trend of the system pressure or the change trend of the work current of the compressor, the quitted defrosting coiler temperature of the current defrosting period is obtained accordingly, and defrosting control over the heat pump water heater is conducted according to the quitted defrosting coiler temperature of the current defrosting period. Accordingly, the purposes of achieving thorough defrosting and solving the problem of too-high high pressure prone to happening in the defrosting process are achieved, the water heating quality is improved, and stable running in a water heating mode is guaranteed.

Description

technical field [0001] The invention relates to the technical field of water heaters, in particular to a heat pump water heater and its defrosting control method and device. Background technique [0002] Heat pump water heaters will frost when they are in hot water production mode, especially in central and northern China. The water machine is more prone to frosting. Moreover, during the defrosting process, due to the high air humidity, the heat exchanger of the unit is severely frosted, which leads to incomplete defrosting and affects the effect of hot water heating; If the defrosting time is too long and the outlet water temperature is too high, the high pressure of the system will rise rapidly instantaneously, which will eventually lead to the high pressure protection phenomenon of the system. [0003] In related technologies, the problems of unclean defrosting and high pressure are solved by bypass devices or adding pressure relief valves, but these methods are all bas...

AI Technical Summary

Problems solved by technology

For this reason, an object of the present invention is to propose a defrosting control method for a heat pump water heater. The method controls the exiting defrosting coil temperature during defrosting through the changing trend of the system pressure or the changing trend of the compressor operating current. Correction, and defrosting control of the heat pump water heater according to the corrected exiting defrosting coil temperature, so as to achieve the purpose of clean defrosting and solve the problem of high pressure and high pressure during defrosting

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