The control method to solve the shortage of refrigerant in multi-connected air-conditioning units

Abstract

The invention discloses a control method for solving the problem of shortage of refrigerants of a multi-link air conditioning unit. The control method particularly includes the steps of (1) starting a heating mode, (2) measuring the suction temperature, the low-pressure pressure, the discharge temperature and the high-pressure pressure, (3) judging whether the four conditions that the value obtained by subtracting the saturation temperature corresponding to the low-pressure pressure from the suction temperature is lager than or equal to 15 DEG C, the high-pressure pressure is lower than 2 MPa, the discharge temperature is higher than or equal to 100 DEG C, and the opening degree of an outdoor unit electronic expansion valve (7) is larger than or equal to 450 steps are met at the same time or not, and continuously executing the following steps if the four conditions are met at the same time, (4) starting a closest indoor unit, (5) judging whether the conditions that the value obtained by subtracting the saturation temperature corresponding to the low-pressure pressure from the suction temperature is smaller than or equal to 8 DEG C, the high-pressure pressure is higher than 2.4 MPa, and the discharge temperature is lower than or equal to 95 DEG C are met at the same time or not, and continuously executing the following steps if the conditions are not met at the same time, and (6) starting other indoor units, and then executing the step (5). According to the control method, refrigerants are not required to be manually added.

Description

technical field [0001] The invention relates to a multi-connected air-conditioning unit, in particular to a control method for solving the problem of insufficient refrigerant in the multi-connected air-conditioning unit. Background technique [0002] The multi-connected air conditioner unit in the prior art includes an outdoor unit, multiple indoor units, and two refrigerant circulation main pipes connecting each indoor unit and outdoor unit. Multiple indoor units are connected in parallel. The circulation main pipe communicates with the outdoor unit. [0003] Each outdoor unit includes compressor, oil separator, four-way reversing valve, outdoor heat exchanger (evaporator in heating mode), outdoor unit electronic expansion valve and gas-liquid separator. The outlet of the compressor is connected with one end of the oil separator, the other end of the oil separator is connected with the first valve port of the four-way reversing valve, and the third valve port of the four-w...

AI Technical Summary

Problems solved by technology

[0007] During the long-term use of multi-connected units, objectively there is refrigerant leakage, which leads to less refrigerant in the system; or, although there is no leakage of refrigerant, the changes in temperature and pressure caused by climate change make the original appropriate amount Low refrigerant

This will inevitably lead to unsatisfactory heating effect and cannot meet the needs of users.

The existing technology can only deal with the above situation by professional maintenance personnel who come to the door to add refrigerant, which is troublesome and can only be solved after the professional maintenance personnel are in place. The speed is slow, the efficiency is low, and labor costs are consumed. In the large system of multi-connected air conditioners, it is impossible to judge the amount of additional refrigerant. It often happens that too little refrigerant is added once, and the problem is still not solved.

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