Electronic expansion valve control method and air conditioning system

Abstract

The invention discloses a control method of an electronic expansion valve and an air-conditioning system. The control method includes: detecting the current frequency of the compressor at intervals of Δt; judging whether the current frequency is lower than the set frequency; Secondary frequency comparison; judge whether the absolute value of the difference between the current frequency and the previous frequency is greater than the set frequency difference, and if so, adjust the opening of the electronic expansion valve to the reference opening, which is determined according to the current outdoor ambient temperature; After the expansion valve is adjusted to the reference opening, it runs for a preset time; after the electronic expansion valve runs for a preset time at the reference opening, it detects the current discharge temperature of the compressor, and the detected discharge temperature is the detected discharge temperature; according to the detection The difference between the exhaust gas temperature and the target exhaust temperature adjusts the opening of the electronic expansion valve accordingly. According to the control method of the electronic expansion valve of the present invention, the opening degree adjustment efficiency of the electronic expansion valve can be improved, and the air conditioning system can be quickly adjusted to the optimal operating state.

Description

technical field [0001] The invention relates to the field of air conditioning equipment, in particular to a method for controlling an electronic expansion valve and an air conditioning system. Background technique [0002] In related technologies, the electronic expansion valve usually maintains a fixed opening when the air-conditioning system is turned on to prevent oil plugging, and then adjusts the opening according to the corresponding control logic, while the air-conditioning system with frequency conversion function compresses under different conditions and needs. The frequency span of the machine is very large, and the output pressure of the compressor is small when the compressor frequency is low. In order to maintain a certain system pressure difference, the opening of the electronic expansion valve needs to be adjusted to a small state at this time. The flow rate is small, and the opening of the electronic expansion valve needs a wide range of changes to cause the ...

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Problems solved by technology

[0002] In related technologies, the electronic expansion valve usually maintains a fixed opening when the air-conditioning system is turned on to prevent oil plugging, and then adjusts the opening according to the corresponding control logic, while the air-conditioning system with frequency conversion function compresses under different conditions and needs. The frequency span of the machine is very large, and the output pressure of the compressor is small when the compressor frequency is low. In order to maintain a certain system pressure difference, the opening of the electronic expansion valve needs to be adjusted to a small state at this time. The flow rate is small, and the opening of the electronic expansion valve needs a wide range of changes to cause the change of the compressor discharge temperature. Excellent running status

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