Air conditioner and its antifreeze protection control method and control device

Abstract

The invention discloses an air conditioner and its anti-freezing protection control method and control device. The method includes: when the air conditioner is in cooling operation, obtaining the first pressure of the refrigerant at the first position inside the refrigerant pipeline of the evaporator, The second pressure of the refrigerant at the second location and the third pressure of the refrigerant at the outlet of the evaporator are respectively compared with the anti-freezing pressure; in satisfying the smaller value of said first pressure and said second pressure When the condition is less than the first anti-freezing pressure, anti-freezing protection is implemented, and the conduction of the refrigerant bypass between the first position and the second position is controlled, so that the refrigerant flows from the high-pressure side through the refrigerant bypass flow to the low-pressure side; when the condition that the third pressure is lower than the second anti-freezing pressure is met, the anti-freezing protection is executed, and the auxiliary electric heating device in the indoor unit is controlled to turn on. The application of the invention can improve the reliability of the anti-freezing protection control, shorten the processing time of the anti-freezing protection, and improve the cooling comfort.

Description

technical field [0001] The invention belongs to the technical field of air conditioning, in particular relates to an air conditioner and its control, more specifically relates to an air conditioner and its anti-freezing protection control method and control device. Background technique [0002] When the air conditioner is running at a low load for cooling, frosting often occurs on the evaporator of the indoor unit. After the evaporator is frosted, the air conditioner starts anti-freezing protection, and by reducing the frequency of the compressor or stopping the operation of the compressor, the temperature of the evaporator rises to solve the problem of evaporator frosting. [0003] In the prior art, temperature is usually used as a judgment parameter to judge whether the evaporator is frosted, and whether anti-freezing protection needs to be activated. Specifically, the temperature sensor is used to detect the temperature on the outer surface of the evaporator pipeline, th...

AI Technical Summary

Problems solved by technology

[0004] However, the temperature sensor can only collect the temperature at a certain point on the outer surface of the pipeline, and cannot accurately represent the temperature of the entire evaporator

If multiple temperature sensors are installed, the cost is high, the structure is complicated, and the processing process is complicated

Moreover, the temperature of the outer surface of the pipeline detected by the temperature sensor is easily affected by external factors, such as the external environment temperature, thermal insulation sheath, etc., resulting in low temperature detection accuracy

Therefore, the use of temperature as a judgment parameter has limitations, and it is easy to cause misjudgment of frosting on the evaporator, and the reliability of anti-freezing protection is poor.

Moreover, in the prior art, after the anti-freeze protection is activated, the compressor needs to be controlled and the temperature of the evaporator rises. This process takes a long time, and the cooling effect is affected when the frequency of the compressor is reduced or stopped, which reduces the temperature comfort.

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