Multi-connected system and its control method for heating throttling element

Abstract

The invention discloses a multi-connected system and a method for controlling heating and throttling elements thereof. The method includes: when the multi-connected system operates in pure cooling or main cooling mode, obtaining the second heat exchange flow of the first heat exchanger The first temperature at the outlet of the channel, and obtain the first saturation temperature corresponding to the pressure at the outlet of the second heat exchange flow channel of the first heat exchanger, and calculate the degree of superheat according to the first temperature and the first saturation temperature; obtain the second The second temperature at the outlet of the first heat exchange flow path of the second heat exchanger, and obtain the second saturation temperature at the outlet of the first heat exchange flow path of the second heat exchanger, and according to the second temperature and the second Calculate the degree of subcooling based on the saturation temperature; adjust the opening of the heating throttling element according to the degree of superheat and subcooling. This method can adjust the heating throttling element according to the degree of superheat and subcooling, so that the opening degree of the heating throttling element can be optimized, so that the system can obtain a lower exhaust temperature and a better cooling effect. And high energy efficiency.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a method for controlling a heating throttling element in a multi-connection system and a multi-connection system. Background technique [0002] The multi-connected system has four modes: pure cooling, pure heating, main cooling and main heating. Among them, the main cooling mode and the main heating mode can use the condensation heat and evaporation heat of the system at the same time, which greatly improves the energy efficiency of the system. [0003] However, when the system is in pure cooling and main cooling mode, if the outdoor temperature and indoor temperature are relatively high, the evaporation temperature of the indoor unit is high, the cooling effect is poor, and the return air temperature of the cooling indoor unit is relatively high. As a result, the exhaust temperature and superheat of the compressor in the outdoor unit will increase accordingly, which in...

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Problems solved by technology

[0003] However, when the system is in pure cooling and main cooling mode, if the outdoor temperature and indoor temperature are relatively high, the evaporation temperature of the indoor unit is high, the cooling effect is poor, and the return air temperature of the cooling indoor unit is relatively high. As a result, the discharge temperature and superheat of the compressor in the outdoor unit will increase accordingly, which in turn will cause the risk of excessive discharge temperature in the system

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