Oil return control method and device for air-conditioning system and air-conditioning system

Abstract

The invention discloses an air-conditioning system injection return oil control method and device and an air-conditioning system. The method includes: when it is detected that the injection oil return solenoid valve is closed, timing the oil return operation time of the compressor from zero, and continuously calculating the exhaust superheat degree of the exhaust pipe; if the first preset condition is met, controlling the injection return operation time The oil solenoid valve is turned on; the first preset condition includes that the compressor has been turned on for at least the first preset time, the accumulative operating time of the oil return of the compressor exceeds the second preset time, and the discharge superheat degree reaches at least the second preset time for the third preset time. A preset value; when it is detected that the compressor is turned off or the injection oil return electromagnetic valve is continuously opened for a fourth preset time, the injection oil return electromagnetic valve is controlled to close. Adopting the technical solution provided by the present invention can not only recover the refrigeration oil to the compressor in time, but also avoid bringing more refrigerant liquid to the compressor to cause liquid shock in the compressor, thereby improving the reliability and safety of injecting and returning oil sex.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a method and device for controlling oil return of an air-conditioning system and an air-conditioning system. Background technique [0002] In today's economic society, air conditioners are welcomed by people because of their good refrigeration and other effects, and are widely used. [0003] For an air conditioning system with a flooded shell and tube evaporator, since the refrigerant liquid is evaporated inside the flooded shell and tube evaporator, the refrigerant oil will be stored at the bottom of the shell and tube. If it is not led back to the compressor in time, it will As the cycle continues, more and more refrigerated oil will accumulate at the bottom of the shell and tube, causing the compressor to lack oil, affecting the reliability and performance of the compressor, and eventually making the compressor unable to operate normally. At present, the refrigerated...

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Problems solved by technology

[0004] However, due to the lack of effective control of the injection oil return technology, the current injection oil return technology cannot realize that the refrigeration oil can be recovered to the compressor in time, and it can also avoid bringing more refrigerant liquid to the compressor to cause compression. The machine liquid hits or even burns the compressor, with low reliability and safety

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