Electronic expansion valve control method and device in heat pump air conditioning system

Abstract

The invention relates to the technical field of air conditioner control, in particular to an electronic expansion valve control method and device in a heat pump air conditioning system. The method comprises the following steps: acquiring pressure at the suction end of an electric compressor and temperature at an outlet of a vehicle interior heat exchanger; calculating an actual superheat degree through the pressure at the suction end of the electric compressor and the temperature at the outlet of the vehicle interior heat exchanger; acquiring a heating or refrigeration state sent by a panel of an air conditioner, and setting a target superheat degree according to the heating or refrigeration state; differencing the actual superheat degree and the target superheat degree to obtain a superheat degree deviation; and determining a current opening degree of an electronic expansion valve according to the superheat degree deviation, and sending the opening degree of the electronic expansion valve to the electronic expansion valve to control work of the electronic expansion valve. Through the electronic expansion valve control method and device, the control accuracy and the stability of the heat pump air conditioning system are improved.

Description

technical field [0001] The invention relates to the technical field of air conditioning control, in particular to a method and device for controlling an electronic expansion valve in a heat pump air conditioning system. Background technique [0002] In order to meet the comfort of customers and the needs of defrosting and defogging of vehicles, most of the cars are equipped with air conditioning systems. The air conditioning system consists of a refrigeration system and a heating system. Traditional fuel vehicles use the engine as the power source, the cooling is realized by the 12V air-conditioning compressor on the engine, and the heating is realized by the waste heat of the engine cooling system. Since the pure electric vehicle has no engine and only uses the driving motor as the power source, its air conditioning system belongs to an electric air conditioning system, that is, the cooling is realized by an independent 320V high-voltage electric compressor, and the heatin...

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Problems solved by technology

[0008] In the prior art, the electronic expansion valve control in the heat pump air-conditioning system generally obtains the electric compressor pressure from the heat pump controller and directly uses the look-up table method to obtain the opening degree of the electronic expansion valve, and finally forms the opening degree control table, but once the opening degree control table, the adjustment is relatively simple, but it is not easy to control finely, and the adaptability is poor; and the actual heat pump air-conditioning system often has strong nonlinearity, time-varying and hysteresis. Therefore, in the prior art, the direct look-up table method of the electronic expansion valve Not adaptive

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