Air conditioner for defrost and variable-frequency heat pump

Abstract

The invention provides an air conditioner for a defrost and variable-frequency heat pump, which comprises an indoor unit and an outdoor unit. The outdoor unit comprises a condenser, a fan, a reversing four-way valve and a compressor, wherein one end of the condenser is connected with the indoor unit through a connection pipeline, and the other end is connected with the compressor and the indoor unit through four-way valves; cut-off valves are arranged among the indoor unit, the condenser and the four-way valves; a throttle mechanism is arranged between a cut-off valve on the connection pipeline and the condenser; and a pipeline heating device is arranged between the throttle mechanism and the condenser. The air conditioner for the heat pump is free from heat loss during the defrost process, can better keep the indoor temperature constant, has less temperature fluctuation and improves the indoor comfort.

Description

technical field [0001] The invention belongs to the technical field of air conditioners, in particular to a heat pump air conditioner with a defrosting function. Background technique [0002] Existing air source heat pump type inverter air conditioners perform heating operation in a low temperature environment. When the evaporation temperature of the refrigerant in the outdoor heat exchanger is lower than zero and the humidity of the air reaches a certain condition, the surface of the fins of the outdoor heat exchanger will gradually Frosting, when the frost layer reaches a certain level, the heat transfer effect drops sharply. At this time, it is necessary to perform defrosting operation. Through the action of the four-way valve, the flow direction of the refrigerant changes, and the high-temperature and high-pressure gas flows into the outdoor heat exchanger to cool the throttling. The low-pressure low-temperature liquid needs to evaporate indoors to absorb a certain amoun...

AI Technical Summary

Problems solved by technology

[0002] Existing air source heat pump type inverter air conditioners perform heating operation in a low temperature environment. When the evaporation temperature of the refrigerant in the outdoor heat exchanger is lower than zero and the humidity of the air reaches a certain condition, the surface of the fins of the outdoor heat exchanger will gradually Frosting, when the frost layer reaches a certain level, the heat transfer effect drops sharply. At this time, it is necessary to perform defrosting operation. Through the action of the four-way valve, the flow direction of the refrigerant changes, and the high-temperature and high-pressure gas flows into the outdoor heat exchanger to cool the throttling. The low-pressure low-temperature liquid needs to evaporate indoors to absorb a certain amount of heat to maintain the balance of the system, which will lead to discontinuous indoor heating, and even cause indoor heat loss. When the refrigerant flow direction is switched again after defrosting is completed, part of the heat will be lost to balance the evaporator. As the temperature rises, the compressor consumes energy to establish a stable pressure balance, further losing heat and exacerbating room temperature fluctuations. This is an inherent problem with traditional reversing defrosting heat pump air conditioners.

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