Heat pump air conditioning system and its defrosting method

Abstract

The invention provides a heat-pump air conditioning system which comprises an indoor heat exchanger, an outdoor heat exchanger, a compressor, a four-way valve, a heat accumulator and a heat accumulation circuit. The four-way valve is respectively communicated with an air suction end and an exhaust end of the compressor, the indoor heat exchanger and the outdoor heat exchanger and is connected with the air suction end of the compressor by a first pipeline; the heat accumulator wraps the outer wall of the compressor; the heat accumulator is serially connected onto the heat accumulation circuit, and the heat accumulation circuit is connected with the first pipeline in parallel. The heat-pump air conditioning system has the advantages that heat in the outdoor heat exchanger can be sufficiently utilized, and an air suction superheat degree and an enthalpy value of refrigerants at the air suction end of the compressor can be greatly increased, so that the temperature of refrigerants at the exhaust end of the compressor can be greatly increased, and the defrosting efficiency of the heat-pump air conditioning system can be improved. The invention further provides a defrosting method for the heat-pump air conditioning system.

Description

technical field [0001] The invention relates to the technical field of air-conditioning equipment, and more specifically, relates to a heat pump air-conditioning system and a defrosting method thereof. Background technique [0002] During the heating process of the heat pump air conditioning system, when the outside temperature is low, frost is easy to form on the outdoor heat exchanger, which reduces the heat exchange effect of the outdoor heat exchanger, thus affecting the heating process of the heat pump air conditioning system. When the frosting reaches a certain level, the indoor heating effect is low, and even the indoor heat exchanger cannot be heated, that is, the heating air that is higher than the indoor temperature cannot be blown out. At this time, it is necessary to remove the frost on the outdoor heat exchanger to restore its heat exchange effect and ensure the heating performance of the heat pump air conditioning system. Patent No. CN201180001679.0 discloses ...

AI Technical Summary

Problems solved by technology

The refrigerant absorbs heat and gasifies in the heat accumulator to become a gaseous refrigerant, that is, part of the heat in the heat accumulator is used for the gasification of the refrigerant, and part of it is used to increase the suction superheat and enthalpy of the refrigerant, resulting in the After the refrigerant is heated by the heat accumulator, the suction superheat and enthalpy of the refrigerant will increase slightly, because the refrigerant flowing into the suction end of the compressor from the heat accumulator and the refrigerant flowing into the suction end of the compressor from the outdoor heat exchanger interact with each other. Mixing makes the increase of suction superheat and enthalpy of the refrigerant at the suction end of the compressor smaller, resulting in longer defrosting time required by the above defrosting method and lower defrosting efficiency

[0004] In addition, in the above-mentioned defrosting method, the refrigerant part of the indoor heat exchanger flowing into the expansion valve is introduced into the heat accumulator. Since the heat accumulator is installed on the compressor, the distance between the compressor and the expansion valve and the distance between the compressor and the indoor heat exchanger The distances are relatively long, which leads to a long pipeline for the refrigerant part of the indoor heat exchanger flowing into the expansion valve to be introduced into the accumulator, which makes the pipeline of the entire air conditioning system more complicated, and at the same time, the cost of the air conditioning system is relatively high

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