Frequency conversion multi-connected type heat pump system and control method of bypass electronic expansion valve

Abstract

The invention discloses a frequency conversion multi-connected type heat pump system and a control method of a bypass electronic expansion valve. The system comprises a gas-liquid separator, a compressor and the bypass electronic expansion valve; the inlet end of the gas-liquid separator is connected with a first port of a four-way reversing valve; and the suction end of the compressor is connected with the outlet end of the gas-liquid separator, and the exhaust end of the compressor is connected with a third port of the four-way reversing valve. One end of the bypass electronic expansion valve is connected with the exhaust end of the compressor, the other end of the bypass electronic expansion valve is connected with the inlet end of the gas-liquid separator, and the bypass electronic expansion valve is used for throttling refrigerants output by the compressor by adjusting the opening degree. The bypass electronic expansion valve is arranged between the gas-liquid separator and the compressor, and therefore when the system is started, the proper system pressure can be rapidly built, so that the system can work under the optimum pressure state; the surplus capacity of the system can be effectively unloaded, and it is ensured that the system can safely and stably operate; and on the basis that an existing refrigerant piping scheme of the system is not changed, real-time adjustment and control over the capacity unloading amount of the system can be achieved.

Description

technical field

[0001] The invention relates to the technical field of frequency conversion multi-connection heat pump systems, in particular to a control method for a frequency conversion multi-connection heat pump system and a bypass electronic expansion valve. Background technique

[0002] The frequency conversion multi-connected heat pump system is composed of an outdoor unit and an indoor unit connected by refrigerant pipelines. The outdoor unit is composed of an outdoor heat exchanger, a compressor and other refrigeration accessories; the indoor unit is composed of a fan and a direct evaporator. An outdoor unit can deliver refrigerant liquid to several indoor units through pipelines, and by controlling the refrigerant circulation volume of the compressor and the refrigerant flow rate entering each heat exchanger in the room, it can timely meet the indoor cooling and heating load requirements.

[0003] On the one hand, in the initial stage of the system start-up of the ...

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