Method for judging defrosting of heat pump water heater

Abstract

A method for judging defrosting of heat pump water heater includes setting evaporation temperature sensor and defrosting temperature sensor on outdoor unit heat exchanger, detecting evaporation temperature T1 and defrosting temperature T2 during heating mode operation, setting evaporation temperature sensor and defrosting temperature sensor on outdoor unit heat exchanger, setting evaporation temperature sensor and defrosting temperature sensor on outdoor unit heat exchanger, setting evaporation temperature sensor and defrosting temperature sensor on outdoor unit heat exchanger, setting defrosting temperature sensor on outdoor unit heat exchanger and detecting defrosting temperature T2 during heating mode operation. Step S2: Judge T2-Whether T1 > [delta] T is tenable or not, if so, it is not frosted, and continues to operate under normal heating condition; 3 if not, proceed to step 3; 3, enter defrosting mode; Step S4: Judge T1 Whether T 2 >=[delta] T 'is true or not, if so, defrost mode should be maintained; If not, exit defrosting mode and return to heating mode. The method provided by the invention can judge whether the outdoor heat exchanger is frosted or not, so as to defrostthe outdoor heat exchanger accurately and efficiently.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a method for judging defrosting of a heat pump water heater. Background technique [0002] When the heat exchanger of the air source heat pump water heater is placed in an outdoor environment, when the ambient temperature is low and the air moisture content is high, frosting will appear on the surface of the heat exchanger. The frosting characteristic is that at the same temperature, the humidity content The bigger it is, the worse the frosting will be. [0003] At present, the defrosting method of the mainstream air source water heaters on the market is to install a temperature sensor on the outdoor heat exchanger to detect the temperature of the outdoor pipeline, so as to judge whether there is frosting. The through valve is energized to make the heat pump reverse cycle, turn off the indoor unit fan, and the high-temperature and high-pressure gas from the compressor o...

AI Technical Summary

Problems solved by technology

When using this defrosting method, since the defrosting time is fixed, the heat absorbed by the refrigeration cycle of the air source heat pump water heater from the air within a certain period of time is not certain, especially when the outdoor ambient temperature is very low, the heat The fluctuation is more unstable. At this time, if the timed defrosting is used, the frost layer will not be completely melted, or the defrosting program is still running after the defrosting, which will affect the hot water production speed and the service life of the compressor.

[0006] It can be seen that only one outdoor heat exchanger temperature sensor cannot be used to judge whether the outdoor heat exchanger is frosted, so that the outdoor heat exchanger cannot be defrosted accurately and efficiently.

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