Air conditioning system and air conditioning unit as well as oil return control system and oil return control method thereof

Abstract

The invention discloses an air conditioning system and an air conditioning unit as well as an oil return control system and an oil return control method thereof. The air conditioning unit comprises a plurality of compressors, wherein the plurality of compressors are installed in parallel, oil balance tubes are respectively connected between oil tanks of any two compressors, and a gas-liquid separator of the air conditioning unit is used for making oil return to each compressor through a plurality of oil return pipelines which are correspondingly connected with the plurality of compressors. The oil return control system comprises a plurality of pressure detection devices, a plurality of switching devices and a processing device, wherein the plurality of pressure detection devices are correspondingly arranged on air suction pipelines or oil tanks of the plurality of compressors respectively, the pressure detection devices are used for detecting pressure applied to the air suction pipelines or the oil tanks of the corresponding compressors, the plurality of switching devices are correspondingly arranged on of the multiple oil return pipelines respectively, and the processing device is used for controlling the opening time of the plurality of switching devices according to pressure values detected by the plurality of pressure detection devices. According to the oil return control system, the oil return balance of each compressor can be preferably guaranteed, and the operating reliability of the air conditioning unit can be increased.

Description

technical field [0001] The invention belongs to the technical field of electric appliance manufacturing, and in particular relates to an oil return control system of an air-conditioning unit, an air-conditioning unit and an air-conditioning system with the oil return control system, and an oil return control method of the air-conditioning unit. Background technique [0002] For an air conditioning system with multiple compressors connected in parallel, it is a difficult point in this field to realize the oil level balance of each compressor. In the existing solutions, most of the oil balance pipes and air balance pipes are added to ensure the oil level balance of the oil sumps of two or more parallel compressors. However, even if the oil balance pipe is designed, there will still be a small pressure difference between the oil chambers of the compressors, which will also cause a large oil level difference, which will cause the oil level of each compressor to be unbalanced. If...

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Problems solved by technology

However, even if the oil balance pipe is designed, there will still be a small pressure difference between the oil chambers of the compressors, which will also cause a large oil level difference, which will cause the oil level of each compressor to be unbalanced. If the oil return control Imbalance, for example, one part of the compressors with too much lubricating oil, while another part of the compressors has insufficient lubricating oil, which affects the reliable operation of the air conditioning unit and presents a risk

[0003] The current scheme must ensure that there is only a very small pressure difference in the oil tank of each compressor, and the design of the low-pressure pipeline requires high manufacturing consistency and machining accuracy. It is difficult to check out before the test, which greatly increases the difficulty of checking the reliability of oil return balance

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