Control method for air conditioner freezing protection

Abstract

The invention discloses a control method for air conditioner freezing protection, and belongs to the field of air conditioners. The method comprises the steps that during air conditioner refrigerationor dehumidification operation, the temperature values of an inlet and an outlet of an indoor unit heat exchanger are obtained; the difference value of the temperature values of the inlet and the outlet is compared with a first temperature preset value, and the compressor frequency is controlled according to the comparison result; and the absolute value of the difference value of the temperature values of the inlet and the outlet is compared with a second temperature preset value, a freezing area is judged according to the comparison result, and a corresponding freezing protection mechanism isstarted. According to the absolute value and the positive and negative values of the temperature difference of the inlet and the outlet of the air conditioner indoor unit heat exchanger, thin pipe side freezing produced by reduction of evaporation pressure and evaporation temperature due to excessive throttling or refrigerant insufficiency can be clearly judged, thick pipe side freezing producedby large pressure loss due to poor pipeline bypass or deformation of a flow path structure can also be clearly judged, and anti-freezing protection is carried out specifically according to preset temperature and preset time.

Description

technical field [0001] The invention belongs to the field of air conditioners, in particular to a control method for freezing protection of an air conditioner. Background technique [0002] When the air conditioner is cooling or dehumidifying, the heat exchanger of the indoor unit is always at a low temperature, which is prone to freezing, which will affect the cooling effect of the air conditioner and make its cooling capacity weaker and weaker. Therefore, when the air conditioner is in cooling or dehumidifying operation, it is necessary to ensure that the heat exchanger of the indoor unit of the air conditioner does not freeze. [0003] In order to monitor the freezing phenomenon of the indoor unit coil, the existing air conditioner usually installs a temperature sensor on the indoor unit coil, so that the air conditioner can judge the freezing condition of the indoor unit coil through the temperature of the indoor unit coil. So that when the coil of the indoor unit freez...

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Problems solved by technology

[0004] However, the above-mentioned existing monitoring methods have monitoring limitations. First, the accuracy of this monitoring method needs to rely on the shunt flow of the heat exchanger, that is, when the shunt flow of the heat exchanger of the indoor unit is not good, only relying on the set temperature One branch of the sensor makes it difficult to accurately judge the freezing condition of the entire indoor unit coil; second, when the freezing occurs at a position behind the coil setting point (thick pipe end), the heat exchanger of the indoor unit cannot be monitored in time. Freezing of

It can be seen that it is difficult for the air conditioner to effectively judge the overall freezing of the indoor unit only by the temperature of the inner coil; therefore, the air conditioner cannot deal with the freezing of the indoor unit in time, which seriously affects the heat exchange efficiency of the air conditioner , resulting in a degraded user experience

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