Multi-split system and switching control method of operating mode of indoor units thereof

Abstract

The invention discloses a multi-split system and a switching control method of an operating mode of indoor units thereof. The switching control method comprises the following steps that when any of the multiple indoor units receives a mode switching instruction, the indoor unit sends the mode switching instruction to a flow dividing device; and the flow dividing device conducts switching control over a heating control valve or a refrigerating control valve corresponding to the indoor unit according to the received mode switching instruction, releases pressure by controlling a second throttling assembly, a first control valve and a bypass valve so as to decrease the front-back pressure difference of the refrigerating control valve or the heating control valve corresponding to the indoor unit, obtains the switching flag bit of a four-way valve, and controls the refrigerating control valve or the heating control valve and the four-way valve corresponding to the indoor unit according to the switching flag bit of the four-way valve, hidden pipeline cracking dangers caused by impact of coolants are better avoided accordingly, corresponding coolant impact noise is reduced, and the reliability of the system and the noise quality are improved.

Description

technical field [0001] The invention relates to the technical field of air conditioning, and in particular to a switching control method of an indoor unit operating mode in a multi-connection system and a multi-connection system. Background technique [0002] The multi-connected system is a high-efficiency air-conditioning unit that reasonably distributes the refrigerant in the high-pressure pipe and low-pressure pipe of the outdoor unit to the corresponding heating indoor unit or cooling indoor unit through several control valves in the flow distribution device to achieve simultaneous heating and cooling. . [0003] In the related art, when the indoor unit performs mode switching and does not involve a large mode switching (that is, the four-way valve in the outdoor unit does not need to be switched), the indoor unit will switch from the heating (cooling) mode to the cooling (heating) mode when it receives When the switching command is issued, the heating control valve (co...

AI Technical Summary

Problems solved by technology

However, during the switching process, when the refrigeration control valve (heating control valve) is opened, the pressure difference on both sides of the refrigeration control valve (heating control valve) is large, and the impact of the refrigerant will cause large pipeline vibrations, and the corresponding pipeline There is a hidden danger of impact cracking in the road system. At the same time, a large refrigerant impact will generate impact noise, which will affect the noise quality of the product

[0004] When the mode switching of the indoor unit involves large mode switching (that is, the four-way valve in the outdoor unit needs to be switched), the four-way valve in the outdoor unit and the cooling control valve (heating control valve) in the splitter device are independently Switching, that is, switching twice, will have two large impacts on the corresponding pipeline system and two refrigerant impact noises, which will seriously affect the reliability of the pipeline system and the noise quality of the product

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