Control method and device for electronic expansion valves of air cooling screw unit

Abstract

The invention discloses a control method and device for electronic expansion valves of an air cooling screw unit. The air cooling screw unit comprises a compressor, the multiple electronic expansion valves, a plurality of four-way valves and a plurality of fin heat exchangers, and each fin heat exchanger is equipped with one electronic expansion valve and one four-way valve. The control method comprises the steps that a current air suction superheat degree of the air cooling screw unit is obtained every other preset time, and a deviation between the current air suction superheat degree and a preset air suction superheat degree is obtained; a change rate of air suction superheat degrees within a preset time is obtained; and the opening degree of the multiple electronic expansion valves is controlled according to the deviation of the air suction superheat degree, the change rate of air suction superheat degrees and a first preset control table. The flow rate and flow direction of coolants can be accurately controlled through the method, and the operation efficiency of the unit is improved. In addition, each fin heat exchanger can defrost independently through composite control of the corresponding electronic expansion valve and the corresponding four-way valve, and continuous heating of the unit is achieved, so that the user experience is improved.

Description

technical field [0001] The invention relates to the technical field of air conditioners, in particular to an electronic expansion valve control method and control device for an air-cooled screw unit. Background technique [0002] At present, the flow of refrigerant in most air-cooled screw units is mainly controlled by orifice plates or electronic expansion valves, and they are uniformly throttled and then flow to all condensing flow paths without control, which may lead to control of refrigerant flow and flow direction. Inaccurate, reducing unit efficiency. In addition, the air-cooled screw unit must control the reversing of the four-way valve during defrosting. However, at this time, the air-cooled heat pump unit in the air conditioner cannot continue to supply heat to the user side, resulting in poor user experience. Contents of the invention [0003] The object of the present invention is to solve one of the above-mentioned technical problems at least to a certain ext...

AI Technical Summary

Problems solved by technology

[0002] At present, the flow of refrigerant in most air-cooled screw units is mainly controlled by orifice plates or electronic expansion valves, and they are uniformly throttled and then flow to all condensing flow paths without control, which may lead to control of refrigerant flow and flow direction. Inaccurate, reducing unit efficiency

In addition, the air-cooled screw unit must control the reversing of the four-way valve during defrosting. However, at this time, the air-cooled heat pump unit in the air conditioner cannot continuously supply heat to the user side, resulting in poor user experience.

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