Air-conditioning system and control method for same

Abstract

The invention discloses an air-conditioning system and a control method for the same. The air-conditioning system comprises a plurality of outdoor units, a plurality of indoor units connected with the plurality of outdoor units through a liquid pipe, a low-pressure gas pipe and a high-pressure gas pipe separately, a plurality of expansion valves in one-to-one correspondence with the heat exchangers of the plurality of outdoor units, and serially connected between the liquid pipe and the plurality of outdoor units, and a controller adjusting the opening degrees of the corresponding expansion valves taking the heat exchangers as evaporators, of the outdoor units, in the plurality of outdoor units according to the outlet temperatures of the heat exchangers of the refrigeration indoor units, and adjusting the corresponding expansion valves taking the heat exchangers as condensers, of the outdoor units, in the plurality of outdoor units according to the middle-part temperatures of the heat exchangers of the heating indoor units after the air-conditioning system enters a mixed mode. Through the accurate adjustment of the air-conditioning system disclosed by the invention for the opening degrees of the electronic expansion valves of the outdoor units, the refrigeration and heating capacity of the mixed mode under a low-temperature environment of the outdoor units can be improved, and meanwhile, the enough superheat degree of a compressor is ensured and the system reliability is improved.

Description

technical field [0001] The invention relates to the technical field of air-conditioning manufacturing, in particular to an air-conditioning system and a control method for the air-conditioning system. Background technique [0002] The three-pipe air-conditioning system includes multiple outdoor units and multiple indoor units. The heat exchanger of the outdoor unit may be a condenser or an evaporator. In related technologies, the electronic expansion valve corresponding to each outdoor unit is adjusted according to the exhaust temperature. , it is difficult to satisfy the stability, reliability and cooling and heating effects under different environments and different operating combinations of indoor units, especially in low-temperature environments, the exhaust temperature is generally low, and the electronic expansion valve sometimes does not work in a small temperature range. However, for the three-pipe air-conditioning system at this time, since some indoor units are in ...

AI Technical Summary

Problems solved by technology

[0002] The three-pipe air-conditioning system includes multiple outdoor units and multiple indoor units. The heat exchanger of the outdoor unit may be a condenser or an evaporator. In related technologies, the electronic expansion valve corresponding to each outdoor unit is adjusted according to the exhaust temperature. , it is difficult to satisfy the stability, reliability and cooling and heating effects under different environments and different operating combinations of indoor units, especially in low-temperature environments, the exhaust temperature is generally low, and the electronic expansion valve sometimes does not work in a small temperature range. However, for the three-pipe air-conditioning system at this time, since some indoor units are in cooling operation and some are in heating operation at the same time, the ratio of the condenser to the evaporator in the entire refrigeration system needs to change with the different operating modes of the indoor units. That is: it is necessary to adjust the electronic expansion valve in real time to meet the needs

[0003] However, in the current control, the adjustment of the opening of the electronic expansion valve is not fine, which affects the cooling and heating efficiency of the three-pipe air conditioning system

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