Oil return control device and method for air conditioner and air conditioner

Abstract

The invention provides an oil return control device and method for an air conditioner and the air conditioner. The oil return control device comprises a judgment unit and a control unit. The judgment unit is used for judging start of the oil return process and finish of the oil return process. The control unit is used for increasing the compression ratio of a compressor when the judgment unit judges that the oil return process starts. By means of the manner of increasing the compression ratio of the compressor when oil return is needed for a system, the force for pushing a refrigerant to flow can be increased, the flow velocity is accordingly increased, and lubricating oil stored in a heat exchanger and a pipeline can be more easily brought back to a cavity of the compressor. By means of the oil return manner, normal oil return can be achieved, and meanwhile noise caused to an outdoor unit of the air conditioner by the fact that the frequency of the compressor is increased and the rotation speed is increased is also effectively reduced.

Description

technical field [0001] The invention belongs to the technical field of air conditioners, and in particular relates to an oil return control device for an air conditioner, a control method and an air conditioner. Background technique [0002] In the existing inverter air conditioner, when the compressor is running at a low frequency, the flow rate of the refrigerant in the system is relatively low, so the flow rate of lubricating oil brought into the heat exchanger with the refrigerant is greater than the flow rate brought back to the compressor. Long-term operation will cause the compressor to not be effectively lubricated and damage the compressor. [0003] In response to the above problems, air conditioners in the industry return oil by regularly increasing the operating frequency of the compressor, and bring the lubricating oil stored in the heat exchanger back to the compressor. However, in the process of increasing the frequency of the compressor and decreasing the fre...

AI Technical Summary

Problems solved by technology

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the air conditioner in the prior art that the noise of the outdoor unit of the air conditioner increases when the oil returns, thereby providing an oil return control device, a control method and an air conditioner for the air conditioner. device

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