Valve body control method for multi-connected system and its subcooling circuit

Abstract

The invention discloses a valve body control method of a multi-line system and its subcooling circuit. The method includes the following steps: obtaining the exhaust superheat degree of a compressor; when the exhaust superheat degree is less than a first preset value, if The superheat degree of the outlet of the second heat exchange flow path of the first heat exchange component is less than the target superheat degree of the first outlet, then the opening degree of the second throttle valve is controlled to be reduced; when the opening degree of the second throttle valve is adjusted to the minimum If the superheat degree of the outlet of the second heat exchange flow path of the first heat exchange component is less than the target superheat degree of the first outlet, the minimum opening degree shall be corrected down, and the opening degree of the second throttle valve shall continue to be adjusted. Turn down the control until the discharge superheat of the compressor is greater than the second preset value. In this method, when there is a risk of liquid return in the compressor, by adjusting the opening of the second throttle valve, it can not only limit excessive refrigerant from returning to the compressor, but also increase the superheat of the return gas to reduce the risk of liquid return in the compressor, thereby Improve the cooling effect of the system and the safety of operation.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a method for controlling a valve body of a subcooling circuit in a multi-connection system and a multi-connection system. Background technique [0002] The main cooling mode of the multi-line system can use the condensation heat and evaporation heat of the system at the same time to realize simultaneous cooling and heating, which greatly improves the energy efficiency of the system. In the multi-connected system, the outdoor unit can distribute the gas-liquid refrigerant to the indoor units with different cooling and heating requirements through the distribution device, wherein the distribution device is provided with a subcooling circuit. [0003] When the multi-connected system is running in the main cooling mode or pure cooling mode, if the outlet superheat of the cooling indoor unit is too small, or there is more refrigerant at the outlet of the subcooling circuit an...

AI Technical Summary

Problems solved by technology

[0003] When the multi-connected system is running in the main cooling mode or pure cooling mode, if the outlet superheat of the cooling indoor unit is too small, or there is more refrigerant at the outlet of the subcooling circuit and the outlet superheat is small, the gas at the outlet of the cooling indoor unit will be affected. When a strong cooling effect is generated, the return air will easily carry liquid back to the suction port of the compressor. At this time, the exhaust superheat of the system is low, which will affect the safe operation of the system.

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