Central arithmetic type multi-split air conditioner system and state switching control method thereof

Abstract

The invention discloses a central arithmetic type multi-split air conditioner system and a state switching control method of the central arithmetic type multi-split air conditioner system. The operating states of electronic expansion valves and the operating states of compressors are controlled through a central arithmetic unit, the operating frequency and the corresponding gear of each compressor are determined so that the total refrigerating capacity output by the central arithmetic type multi-split air conditioner system can be controlled easily and efficiently, the refrigerating capacity can be reasonably distributed to rooms, and the refrigerating capacity obtained by each room is matched with the heat load of the room. The central arithmetic unit receives temperature signals of all the rooms, carries out centralized arithmetic processing, sends instructions to the electronic expansion valves and the compressors of indoor units, and has control over execution behaviors of the electronic expansion valves and execution behaviors of the compressors. According to the central arithmetic type multi-split air conditioner system and the state switching control method of the central arithmetic type multi-split air conditioner system, mutual influence among the indoor units is taken into overall consideration, the fluctuation range of the indoor temperature is reduced, the probability that the compressors are in the shutdown state in the operating process of the central arithmetic type multi-split air conditioner system is greatly reduced, loss caused by frequent starting and frequent shutdown of the compressors is reduced, and the fluctuation, caused by starting and shutdown of the compressors, of the indoor temperature can be further reduced.

Description

technical field [0001] The invention relates to the control field of a multi-connected air-conditioning system, in particular to a central computing type multi-connected air-conditioning system and a state switching control method thereof. Background technique [0002] The multi-connected air conditioner system is an air conditioner type in which one outdoor unit is connected to multiple indoor units, commonly known as "one-to-many". It was born in 1982. Although it only has a development history of more than 20 years, it has been widely used and developed around the world because of its advantages such as convenient installation, flexible design, good controllability of indoor thermal comfort, and high energy efficiency. For example, in Japan, 50% of medium-sized commercial buildings and one-third of large-scale commercial buildings use multi-connected systems. In China, the total installed capacity of multi-split systems in 2009 has exceeded 30% of the air conditioner mar...

AI Technical Summary

Problems solved by technology

First, the suction pressure or discharge pressure of the compressor is generally used as a parameter to reflect the total cooling capacity demand, so an additional refrigerant pressure sensor needs to be installed, which not only increases the cost but also increases the possibility of refrigerant leakage

Second, artificially changing the superheat setting of the indoor unit to match the cooling demand of the room means that the superheat of the indoor unit cannot be stabilized at the optimum value, which will lead to a decrease in the efficiency of the evaporator When the heat rises, the exhaust temperature of the compressor is too high, which affects the reliability of the long-term operation of the compressor

[0005] The patent document with the publication number CN103206750A discloses a multi-connected air-conditioning system and its state switching control method, which is used to determine the electronic expansion valve controller by obtaining the difference between the actual measured temperature and the preset temperature in a certain room. operating status, and determine the gears and gears of the operating frequency of the compressor, although it is possible to simply and efficiently control the total cooling capacity output by the multi-connected air-conditioning system and reasonably distribute the cooling capacity to each room, but the multiple links disclosed in this patent document The state switching control method of the air conditioning system has certain shortcomings because each room is controlled independently, and the mutual influencing factors are not considered.

First, in some cases, the temperature fluctuation range in the room will be very large; second, because the compressor has a delay start protection function, the indoor temperature fluctuation range will also be large

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