Method and device for controlling electronic expansion valve in heating operation of multi-connected mechanism

Abstract

The invention discloses a method for controlling an electronic expansion valve in the heating operation of a multi-connected mechanism, comprising: obtaining the temperature at the middle of the heat exchanger and the temperature at the outlet of the heat exchanger in all indoor units, and according to the temperature at the middle of the heat exchanger and the temperature at the outlet of the heat exchanger The difference value determines the relative subcooling degree of the corresponding indoor unit; the indoor unit corresponds to the heat exchanger one by one, the indoor unit includes the operating indoor unit and the non-operating indoor unit, and the electronic expansion valve of the indoor unit is in the preset initial valve opening state ; If the relative subcooling degree of any running indoor unit is greater than the preset maximum value of the subcooling degree, the valve closing operation will be performed on the non-running indoor units that meet the preset valve closing conditions; if the relative subcooling degree of the running indoor unit is less than When the preset minimum subcooling degree is reached, the valve opening operation is performed on non-operating indoor units that meet the preset valve opening conditions. The invention also discloses a control device for the electronic expansion valve in the heating operation of the multi-connected mechanism. The embodiment of the present invention can effectively improve the heating efficiency of the unit, balance the distribution of refrigerant in the system and improve the reliability of the whole unit.

Description

technical field [0001] The invention relates to the technical field of multi-connection control, in particular to a method and device for controlling an electronic expansion valve in multi-connection heating operation. Background technique [0002] The multi-split unit is a relatively complex circulation system composed of one or more outdoor units equipped with several indoor units. When there are many indoor units, the installation conditions, environment and usage characteristics of each indoor unit are different. During the heating operation, for the electronic expansion valve control of the indoor unit in the off / standby state, a fixed valve opening (such as 40~60Pls) is usually used to control the opening of the electronic expansion valve. However, if the fixed valve opening is used in the heating operation The valve opening controls the opening of the electronic expansion valve. On the one hand, since the heating shutdown / standby internal unit is equivalent to a high...

AI Technical Summary

Problems solved by technology

During the heating operation, for the electronic expansion valve control of the indoor unit in the off / standby state, a fixed valve opening (such as 40~60Pls) is usually used to control the opening of the electronic expansion valve. However, if the fixed valve opening is used in the heating operation The valve opening controls the opening of the electronic expansion valve. On the one hand, since the heating shutdown / standby internal unit is equivalent to a high-pressure liquid reservoir, a large amount of compressor lubricating oil and refrigerant will remain in it when the unit is running for a long time. Reliability is affected; on the other hand, the total amount of refrigerant in the system is constant. Since the refrigerant is stored in the shut-down internal unit, the amount of refrigerant in the turned-on internal unit is getting smaller and smaller, and the heating capacity is attenuated.

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