Electronic expansion valve control method and air conditioner for prolonging frosting period

Abstract

The invention discloses an electronic expansion valve control method for prolonging the frosting cycle and an air conditioner. The air conditioner operates in the following mode when it is in the heating mode and the outdoor ambient temperature is lower than the preset temperature threshold: the initial opening is set, and the actual opening is detected in real time. Exhaust temperature, and calculate the absolute value T of the difference between the actual exhaust temperature and the preset target exhaust temperature; when it is detected that the actual exhaust temperature rises and T decreases, compare T with the preset temperature difference threshold Comparison to determine the valve closing rate and valve closing steps of the electronic expansion valve; when it is detected that T is lower than the stable operation threshold, the electronic expansion valve stops acting; when it is detected that the actual exhaust temperature decreases and T increases, T and The preset temperature difference threshold is compared to determine the valve closing rate and valve closing steps of the electronic expansion valve. The present invention judges and adjusts according to the change of the actual exhaust temperature and the absolute value of the difference between the actual exhaust temperature and the target exhaust temperature, and can effectively improve the low-temperature heating capacity.

Description

technical field [0001] The invention belongs to the technical field of air conditioners, and in particular relates to an electronic expansion valve control method and an air conditioner for prolonging the frosting cycle. Background technique [0002] At present, many household inverter heat pump air conditioners in the industry are trying to optimize and improve the low-temperature heating capacity and frosting cycle. Most of the optimization measures are to upgrade the heat exchange system and increase the heat exchange area to improve low-temperature cooling. Thermal capacity and cycle, or the use of air injection to increase enthalpy or multi-stage compression to improve low-temperature heating capacity; these measures all involve increased costs, and the economic benefits are not cost-effective. Through actual test and analysis, it is found that the expansion valve opening control of the electronic expansion valve control method in the industry is not very reasonable, th...

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Problems solved by technology

[0004] However, in the actual air conditioning system with electronic expansion valve control, often due to the unreasonable flow control rate and opening control of the electronic expansion valve, it is difficult to achieve the optimal exhaust gas rise too slowly and low exhaust capacity. Otherwise, the exhaust temperature rises too fast, it is easy to overshoot or trigger overload protection to reduce the frequency, resulting in large fluctuations in system capacity, exhaust and evaporation temperature, and cannot perform stable and efficient capacity output, and large fluctuations in outdoor evaporation temperature will speed up outdoor replacement. The frosting of the heater will shorten the frosting cycle, which will have a great impact on the low-temperature heating capacity and frosting cycle, and will greatly affect the stability and comfort of the room temperature.

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