Method for controlling electronic expansion valve in air conditioner system

Abstract

The invention discloses a method for controlling an electronic expansion valve in an air conditioner system. The method includes the steps that firstly, the electronic expansion valve is started and initialized, the air sucking temperature of a compressor and the valve back temperature of the electronic expansion valve are detected in real time, and the practical superheat degree of the electronic expansion valve is calculated according to the difference of the air sucking temperature of the compressor and the valve back temperature of the electronic expansion valve; the target overheat degree of the electronic expansion valve is set according to the inlet water temperature value of an evaporator and the changing trend of the temperature; the practical overheat degree is compared with the target overheat degree, and the optimal opening degree range of the electronic expansion valve is determined through a closed-loop control system. The method has the advantages that by means of the scheme, the practical overheat degree can be calculated by the system, the practical overheat degree is compared with the set target overheat degree, and the optimal opening degree range is determined. The control method is simplified, the equipment cost is reduced, automatic control over the refrigerant flow and the throttling degree can be achieved, and reliable and safe operation of the equipment system is protected.

Description

technical field [0001] The invention belongs to the technical field of air conditioning, in particular to a method for controlling an electronic expansion valve in an air conditioning system. Background technique [0002] Air-conditioning equipment is generally distinguished according to the heat transfer medium, and the water-to-water heat transfer cycle system is one of the most common categories. At present, water-to-water heat exchange air-conditioning equipment generally uses capillary tubes or thermal expansion valves for throttling, so as to achieve the purpose of optimizing energy exchange efficiency. However, the capillary refrigerant flow rate and throttling degree cannot be automatically regulated, and often can only meet the requirements of certain working conditions. The operation effect is extremely poor under harsh working conditions, the reliability and safety of the system cannot be guaranteed, and the service life of the system is greatly reduced. At the ...

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Problems solved by technology

In the air conditioning industry, the cost of pressure transmitters to detect pressure variables is negligible relative to large air conditioning equipment, but can be considerable relative to small air conditioning equipment

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