Double-stage compressor air-conditioner system and control method thereof

Abstract

The invention provides a double-stage compressor air-conditioner system and a control method of the double-stage compressor air-conditioner system. The double-stage compressor air-conditioner system comprises a double-stage compressor, a four-way valve, an indoor heat exchanger, an outdoor heat exchanger, a flash evaporator, a first electronic expansion valve, a second electronic expansion valve and a control unit, wherein the four-way valve is connected to an exhaust port and a low-pressure inlet of the double-stage compressor; the flash evaporator is connected between the indoor heat exchanger and the outdoor heat exchanger and is connected with a medium-pressure inlet of the double-stage compressor; the first electronic expansion valve is connected between the indoor heat exchanger and the flash evaporator; the second electronic expansion valve is connected between the outdoor heat exchanger and the flash evaporator; in a refrigerating mode, the first electronic expansion valve is a secondary electronic expansion valve; in a heating mode, the second electronic expansion valve is the secondary electronic expansion valve; the control unit is used for controlling the opening degree of the secondary electronic expansion valve, so as to guarantee the pressure balance in the double-stage compressor. According to the technical scheme of the invention, on the premise of guaranteeing that the double-stage compressor is safe and reliable, the usage amount of electromagnetic-valve switching devices is reduced, and the production cost of a product is lowered.

Description

technical field [0001] The invention relates to the technical field of air conditioners, in particular to a two-stage compressor air conditioner system and a control method for the two-stage compressor air conditioner system. Background technique [0002] With the increasing number of people using air conditioners, users have higher and higher requirements for the use of air conditioners. Traditional household air conditioners use one-stage compression compressors, which only have one exhaust port and one return air port, and their heating capacity is relatively poor under ultra-low temperature conditions, which cannot meet the needs of users in cold regions. need. [0003] In view of the above problems, an air conditioner using two-stage compression is proposed in the related art, which achieves a strong heating effect under ultra-low temperature conditions, and is very popular among users. [0004] However, two-stage compression air conditioners have higher requirements ...

AI Technical Summary

Problems solved by technology

[0004] However, two-stage compression air conditioners have higher requirements on air-conditioning manufacturers in terms of reliability. The current two-stage compression air conditioners are all based on high costs, relying on the addition of electronic controls such as solenoid valves and electronic expansion valves. switch to ensure the reliability of the system, and adding solenoid valves and electronic expansion valves will lead to complex control logic

At the same time, if the solenoid valve switching device fails due to device aging or other reasons, it will also cause serious safety hazards.

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