Two-stage compression air conditioning system with defrosting function

Abstract

The invention relates to a two-stage compression air conditioning system with a defrosting function. The two-stage compression air conditioning system with the defrosting function comprises a two-stage compressor, a four-way reversing valve, an outdoor heat exchanger, a first throttling device, a flash evaporator, a second throttling device and an indoor heat exchanger, and also comprises a first bypass pipeline, a heat accumulator and a control valve, wherein the first bypass pipeline is connected between the first end of the outdoor heat exchanger and an air suction opening of the two-stage compressor, the heat accumulator is provided with a first heat exchange pipe and a second heat exchange pipe, the first heat exchange pipe is connected in series onto a pipeline arranged between an exhaust opening of the two-stage compressor and the first end of the indoor heat exchanger, the second heat exchange pipe is connected in series onto the first bypass pipeline, and the control valve is used for controlling coolants to flow back to the air suction opening of the two-stage compressor through the first bypass pipeline or a pipeline arranged between the first end of the outdoor heat exchanger and the air suction opening of the two-stage compressor. The two-stage compression air conditioning system with the defrosting function has the advantages that the defrosting speed is high, the defrosting time is short, the use comfort of users can be ensured, and in addition, the adverse influence on the compressor caused during the defrosting can be avoided.

Description

technical field [0001] The invention relates to the field of air conditioning, in particular to a two-stage compression air conditioning system with a defrosting function. Background technique [0002] During the operation of the air conditioner in the cold winter season, the temperature of the outdoor heat exchanger is lower than the ambient temperature. If the outdoor ambient temperature is lower than 7°C, the surface temperature of the outdoor heat exchanger may be lower than 0°C; if the outdoor ambient humidity is high enough at the same time, this will cause frost or even ice on the outdoor heat exchanger, which will seriously hinder The heat exchange of the outdoor heat exchanger causes the heating performance of the air conditioning system to rapidly and greatly attenuate, which significantly affects the heating effect of the air conditioner, and even causes the air conditioner compressor to fail. For this reason, it is necessary to defrost the outdoor heat exchanger...

AI Technical Summary

Problems solved by technology

Although this defrosting method can solve the above-mentioned problems existing in the traditional defrosting method, since the defrosting method uses the heat generated by the compressor to store heat, the phase change temperature point of the phase change heat storage material used will inevitably be If the temperature is lower, the heat absorption and heat release speed of the heat storage material will be slower, so that the defrosting speed will be slower, and the defrosting time will be prolonged, which will also affect the heating effect and comfort

Especially for the two-stage compression air conditioning system with defrosting function, when heating, due to the existence of the flash evaporator, the refrigerant must be subcooled again when it flows through the flash evaporator, that is, the refrigerant flowing into the outdoor heat exchanger must be at Lower temperatures than single-stage compression, so frosting will be more severe and frequent, so defrosting will be slower

Moreover, defrosting when the accumulator has insufficient heat storage will cause a large amount of refrigerant that cannot be evaporated to enter the compressor, thereby posing a fatal threat to the reliability of the compressor.

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