A method for controlling electronic expansion valves of multi-connected outdoor units

Abstract

The electronic expansion valve control method of multi-connected outdoor units provided by the present invention is more accurate than the existing control based solely on a certain variable, which can not only ensure that the exhaust temperature of the system is controlled within a reasonable range, but also ensure The exhaust pressure is within a reasonable range, which solves the problem that the opening of the electronic expansion valve is more reasonable when the air-conditioning system has too much refrigerant, the exhaust is not high, and the pressure is too high, reducing the vibration and noise of the electronic expansion valve and providing The reliability of the electronic expansion valve and the user's comfort experience.

Description

technical field [0001] The invention relates to the technical field of air conditioning systems, in particular to a method for controlling electronic expansion valves of multi-connected outdoor units. Background technique [0002] In the existing multi-connected air conditioning system, the electronic expansion valve of the outdoor unit of the Japanese company represented by Japan is connected in parallel with a check valve. When the outdoor unit is cooling, the check valve is directly connected, and the diameter of the check valve Larger, most of the refrigerant has passed through the one-way valve, and the opening and closing of the electronic expansion valve have no effect on the passage of the refrigerant through the one-way valve. Instead, it is directly opened to the maximum opening, and the electronic expansion valve of the indoor unit is used for throttling and pressure reduction. [0003] However, there are also some manufacturers in China. The throttling part of t...

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Problems solved by technology

[0004] If it is simply controlled according to the exhaust temperature of the compressor, generally when the exhaust temperature is high, the electronic expansion valve will be opened larger, and when the exhaust temperature is low, the electronic expansion valve will be closed relatively small. There is a problem with this method. Sometimes the exhaust temperature may not be very high due to too much refrigerant in the system, but the pressure will be relatively high. Therefore, if the exhaust temperature is simply controlled, the opening of the electronic expansion valve may be relatively small, especially in extreme cases. The expansion valve is closed very small and the pressure is high. The current electronic expansion valve, when the opening is small and the system pressure is high, generally the electronic expansion valve vibrates greatly and will also generate relatively large noise. , especially the comfort of the user, has been complained by the user, and if it runs for a long time, the electronic expansion valve is prone to failure

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