Defrosting control method and device for air conditioner

Abstract

The invention discloses a defrosting control method for an air conditioner. The defrosting control method comprises the processes that after defrosting is completed by an outdoor heat exchanger each time, the running time of the air conditioner running in a heating mode is obtained; when the running time is longer than the preset time and the temperature of the outdoor heat exchanger is higher than or equal to the preset temperature, a one-way valve is opened so that the air conditioner can be controlled to enter a first defrosting mode to conduct defrosting; and when the running time is longer than the preset time and the temperature of the outdoor heat exchanger is lower than the preset temperature, the air conditioner is controlled to be switched to run in a refrigeration mode so that the air conditioner can enter a second defrosting mode to conduct defrosting. The invention further provides a defrosting control device for the air conditioner. According to the defrosting control method and device for the air conditioner, the defrosting efficiency is improved, and meanwhile, the situation that the comfort of the heat pump air conditioner is seriously affected due to the fact that defrosting is conducted in a refrigeration mode frequently is avoided.

Description

technical field [0001] The invention relates to the technical field of air conditioners, in particular to a defrosting control method and device for an air conditioner. Background technique [0002] When the household heat pump air conditioner is heating in winter, the outdoor heat exchanger acts as an evaporator to absorb heat. When the outdoor ambient temperature is too low or the heating operation time is too long, the temperature of the refrigerant pipe of the outdoor heat exchanger will be lower than At zero temperature, the moisture in the outdoor air condenses into frost on the surface of the outdoor heat exchanger, and even icing occurs. After the outdoor heat exchanger is frosted, the heat transfer resistance between the refrigerant in the pipeline and the air will increase greatly, and then Affect the heating effect of the entire heat pump air conditioner, resulting in a decrease in indoor heating efficiency. [0003] The existing defrosting methods of heat pump a...

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Problems solved by technology

[0002] When the household heat pump air conditioner is heating in winter, the outdoor heat exchanger acts as an evaporator to absorb heat. When the outdoor ambient temperature is too low or the heating operation time is too long, the temperature of the refrigerant pipe of the outdoor heat exchanger will be lower than At zero temperature, the moisture in the outdoor air condenses into frost on the surface of the outdoor heat exchanger, and even icing occurs. After the outdoor heat exchanger is frosted, the heat transfer resistance between the refrigerant in the pipeline and the air will increase greatly, and then Affect the heating effect of the entire heat pump air conditioner, resulting in a decrease in indoor heating efficiency

[0003] The existing defrosting methods of heat pump air conditioners usually adopt the following two defrosting methods. One method is the four-way valve reversing method, which switches from heating mode operation to cooling mode operation. The high-temperature and high-pressure refrigerant discharged by the compressor enter the heat exchanger of the outdoor unit, and exchange heat with the frost layer attached to the heat exchanger of the outdoor unit, thereby achieving the purpose of defrosting. However, due to the reverse operation of the cooling mode, each defrosting of the outdoor unit needs to The heater absorbs heat from the room, and the room temperature will gradually decrease with the defrosting process. To defrost by switching the four-way valve to run the refrigeration mode will seriously affect the comfort of the heat pump air conditioner; another way is to open the one-way valve set between the compressor exhaust port and the outdoor heat exchanger inlet, Part of the high-temperature and high-pressure refrigerant at the compressor exhaust port enters the outdoor heat exchanger for defrosting, but the defrosting efficiency of this method is low

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