Control method of variable refrigerant volume (VRV) multi-link air conditioner

Abstract

The invention relates to a control method of a variable refrigerant volume (VRV) multi-link air conditioner, which controls the flow of refrigerant according to the capability needs of inner units; the calculation method of the capability needs of the inner units comprises the steps that: (1) parameters are set; (2) target output in proportional integral algorithm is calculated; (3) the percentage of the capability needs of the started inner units is calculated; (4) the percentage of the capability needs of the inner units which is not started is calculated; (5) the percentage of the total capability needs of all the inner units is calculated, and when the indoor ambient temperature of an air-conditioner room reaches set temperature, the percentage of the total capability needs of the inner units is equal to zero; when the VRV air conditioner stops working, the percentage of the total capability needs of the inner units is equal to zero; and compared with the prior art, the control method of the VRV multi-link air conditioner has the characteristics that: the reaction speed of an air-conditioning system is higher, the room temperature can be accurately regulated and the energy consumption is lower.

Description

technical field [0001] The invention relates to the field of air conditioner control, in particular to a control method for a VRV multi-connected air conditioner. Background technique [0002] The full name of the VRV air-conditioning system is Varied Refrigerant Volume, referred to as VRV. It is a refrigerant-type air-conditioning system. It uses refrigerant as the delivery medium. The outdoor host is composed of outdoor heat exchangers, compressors and other refrigeration accessories. An indoor unit composed of a direct evaporative heat exchanger and a fan. VRV, which means variable flow, is an air conditioning system that relies on electromechanical frequency conversion technology. [0003] VRV multi-connected air conditioner technology is that one outdoor unit drives multiple indoor units, and the capacity output of the outdoor unit, that is, the flow rate of the refrigerant, is determined according to the capacity demand of the indoor unit. However, the calculation me...

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Problems solved by technology

[0004] (1) The existing calculation method of indoor unit capacity demand does not take into account the difference between the cooling mode and heating mode of the air conditioner: the cooling capacity of the indoor unit in the cooling mode in summer and the heating capacity of the indoor unit in the heating mode in winter are Two completely different capabilities, that is, the air-conditioned room needs cooling in summer, and the indoor unit needs to output cooling capacity; while the air-conditioned room needs heating in winter, and the indoor unit needs to output heat. At the same time, the capacity calibration of the indoor mechanism heating mode and the cooling mode capacity calibration are the same The difference is that the capacity calibration of the heating mode is based on the dry bulb temperature and wet bulb temperature of the air-conditioned room being 20°C and 15°C respectively; and the heat exchanger of the indoor unit is used as a condenser in the heating mode, and the indoor The heat exchanger of the machine is used as an evaporator, and the two situations are completely different; therefore, the response speed of the air conditioning system is relatively slow, and the energy consumption is relatively high

[0005] (2) The existing calculation method of indoor unit capacity demand does not take into account the actual temperature of the air-conditioned room: in summer, the temperature of the air-conditioned room can be as high as 30~45°C during the hottest time in summer; in winter, the temperature of the air-conditioned room is the coldest in winter The temperature can be as low as below 0°C

If the indoor unit capacity requirements are still calculated based on the dry bulb temperature and wet bulb temperature of 27°C and 19°C respectively, it is obviously not in line with the actual environment, so the air conditioning system cannot accurately adjust the room temperature, and the energy consumption is high

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