Control method and device of multi-split air conditioning system

Abstract

The invention discloses a control method and device of a multi-split air conditioning system. The control method comprises the steps that when the current work environment temperature of the multi-split air conditioning system is larger than the temperature threshold value, whether work states of N inner units meet the preset state or not is detected; if yes, the continuous duration when the N inner units are in the preset state can be recorded; and when the continuous duration is larger than or equal to the first duration threshold, M inner units, in the heating standby state, in the N innerunits are adjusted to be in the refrigeration standby states, and the state continues for the second duration, wherein M is an integer smaller than N. According to the control method, under some particular running conditions, refrigerants, containing a large amount of oil, in the inner units are discharged into a gas and liquid separator, and oil lacking conditions of a compressor can be effectively avoided.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a control method for a multi-connected air-conditioning system and a control device for a multi-connected air-conditioning system. Background technique [0002] The multi-connected air-conditioning system with heat recovery function has different internal units, which can run cooling and heating modes at the same time. For multi-connected air conditioning systems, it has obvious advantages. Among them, the heat recovery multi-connected air-conditioning system mainly includes two-pipe heat recovery multi-connected air-conditioning system and three-pipe heat recovery multi-connected air-conditioning system. cooling mode), pure heating mode (indoor unit only operates in heating mode), main cooling mode (indoor unit operates cooling and heating mode at the same time, at this time, the external unit acts as a condenser) and main heating mode (indoor unit simultaneously Runn...

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Problems solved by technology

[0003] In the related technology, when the heat recovery multi-connected air conditioning system operates under some special operating conditions, for example, when the heating operation is performed in an environment with high indoor and outdoor temperatures, the multi-connected system has the main Due to the characteristics of long pipes, large number of internal unit connections, and large refrigerant injection volume, some internal units in standby will contain a large amount of refrigerant, and oil is dissolved in the refrigerant. Therefore, long-term operation with a large amount of fluid will cause the system to lack oil, thus Lack of oil in the compressor

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