Control method and device of multi-split air conditioning system

Abstract

The invention provides a control method and device of a multi-split air conditioning system. The control method of the multi-split air conditioning system comprises the steps that four-way valve reversing requirements of the multi-split air conditioning system are obtained; high pressure and low pressure of the multi-split air conditioning system are obtained, wherein the high pressure is the pressure between an air outlet of a compressor and the air outlet ends of four-way valves of the multi-split air conditioning system, and the low pressure is the pressure between the air suction ends of the four-way valves and an air suction opening of the compressor; the pressure difference between the high pressure and the low pressure of the multi-split air conditioning system is calculated; and the running frequency of the compressor and the opening of throttling devices of the multi-split air conditioning system are subjected to a first-time adjustment and a second-time adjustment. Thus, through the first-time adjustment and the second-time adjustment to the running frequency of the compressor and the opening of throttling devices of the multi-split air conditioning system, the pressure difference between the high pressure and the low pressure of the multi-split air conditioning system is improved, and the reversing failure of the four-way valve in the multi-split air conditioning system is avoided.

Description

technical field [0001] The present invention relates to the technical field of air conditioners, in particular to a control method for a multi-connection system and a control device for a multi-connection system. Background technique [0002] The air conditioning system operates in cooling or heating mode in different scenarios. It needs to change direction through the four-way valve to change the flow direction of the refrigerant. The four-way valve needs a certain pressure difference to switch successfully. If the difference is too large, it is easy to generate noise during reversing; if the reversing pressure difference of the four-way valve is too small, it may cause the reversing failure of the four-way valve and affect the normal operation of the system. [0003] At present, most air conditioning systems in the related art, especially multi-connected parallel systems (heat pumps, heat recovery), set commutation conditions according to frequency. [0004] However, the ...

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Problems solved by technology

[0004] However, the problem with the related technology is that when the indoor unit has a small start-up capacity or a small load, the operating frequency of the outdoor unit is low, and the system's high and low pressure difference is small, which is prone to difficulty in reversing the four-way valve, that is, the current control logic The problem of four-way valve switching under small load of the system is not considered

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