Multi-split system and valve control method of supercooling return circuit of multi-split system

Abstract

The invention discloses a multi-split system and a valve control method of a supercooling return circuit of the multi-split system. The valve control method comprises the following steps that an exhaust superheating degree of a compressor is acquired; when the exhaust superheating degree is less than a first preset value, if an outlet superheating degree of a second heat exchange flow path of a first heat exchange component is less than a first outlet target superheating degree, opening turning-down control is conducted on a second throttling valve; and when the opening of the second throttling valve is adjusted to the smallest, if the outlet superheating degree of the second heat exchange flow path of the first heat exchange component is less than the first outlet target superheating degree, the smallest opening is subjected to turning-down modification, and the opening turning-down control is conducted on the second throttling valve continuously till the exhaust superheating degree of the compressor is greater than a second preset value. According to the valve control method, when the compressor has a liquid return risk, through the adjustment on the opening of the second throttling valve, a situation that excessive refrigerant returns to the compressor is limited, the air return superheating degree can be increased and the liquid return risk of the compressor is reduced, thereby improving the refrigerating effect and the running safety of the multi-split system.

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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