Variable refrigerant flow system preventing compressor return and control method thereof

Abstract

The invention relates to a variable refrigerant flow system preventing compressor return and a control method thereof. The system mainly comprises a refrigerant circulating loop formed by a compressor, an oil separator, a four-way valve, an indoor unit heat exchanger, economizer, a heating electronic expansion valve assembly, an outdoor unit heat exchanger and a gas-liquid separator, an inlet formed in the evaporation side of the economizer is communicated with the bottom of the gas-liquid separator through a liquid outlet pipe, liquid refrigerant in the gas-liquid separator can be guided intothe economizer, and compressor return is prevented. The control method of the system comprises the steps that the compressor air inlet temperature and saturation temperature are compared, whether ornot a liquid return control electronic expansion valve is switched on is determined, by comparing the economizer inlet temperature with the economizer outlet temperature, the opening of the liquid return control electronic expansion valve is adjusted, and safe and efficient operation is achieved.

Description

technical field [0001] The invention relates to an air conditioning system, in particular to a multi-connection system capable of preventing liquid return from a compressor, in particular to a multi-connection system capable of preventing liquid return from a compressor and a control method thereof. Background technique [0002] The multi-connected air conditioning system has the characteristics of long refrigerant pipes, so the amount of refrigerant in the entire system is relatively large. In some specific cases, a large amount of liquid refrigerant will be stored in the outdoor unit, which can easily cause the liquid refrigerant to return directly to the compressor, resulting in compressor liquid shock. Once the liquid hammer phenomenon occurs, the compressor will be damaged immediately, causing serious failure. When a general multi-connected system encounters liquid return from the compressor, it usually prevents compressor liquid shock by closing the electronic expansi...

AI Technical Summary

Problems solved by technology

In some specific cases, a large amount of liquid refrigerant will be stored in the outdoor unit, which will easily cause the liquid refrigerant to return directly to the compressor, resulting in compressor liquid shock.

Once the liquid hammer phenomenon occurs, the compressor will be damaged immediately, causing serious failure

When a general multi-connected system encounters liquid return from the compressor, it usually prevents compressor liquid shock by closing the electronic expansion valve of the system or reducing the frequency of the compressor, but this will lead to a decrease in system performance and affect user experience.

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