Working Principle and Operating Regulation of Refrigerator Air Dryer

The compressed air from the air compressor for the refrigerator air dryer first exchanges heat with the dried low-temperature compressed air in the heat exchanger, lowering the temperature, then enters the evaporator to be further cooled to about 2℃. At this dew point, most of the water in the compressed air has been discharged as liquid, and the compressed air with very little water content enters the adsorption tower to further dry and remove water. Finally, the low-temperature dry compressed air enters the heat exchanger to cool the high-temperature wet air, at the same time, the temperature itself rises, which can prevent the condensation of the outer wall of the compressed air pipeline. After heating, a small part of the compressed air is taken as the regeneration of adsorbent to improve the regeneration efficiency and reduce energy consumption. Heat exchange between refrigerant and compressed air is used to reduce the temperature of compressed air to dew point temperature in the range of 2-10 ℃, so that the moisture content in compressed air tends to be supersaturated, thus removing the moisture content (water vapor composition) in compressed air. When the pressure of compressed air is high, the temperature is low, the ambient temperature is low, and the amount of treated air is small, the low pressure dew point can be obtained. The atmospheric dew point can only reach - 17℃.

Functions of the main components of the refrigerator air dryer:

1. Refrigeration compressor: Refrigeration compressor is the heart of refrigeration system. At present, most compressors adopt fully sealed reciprocating compressor. The refrigerant is elevated from low pressure to high pressure, and the refrigerant circulates continuously, so that the internal heat of the system is continuously discharged into the environment higher than the system temperature.

2. Condenser: The function of the condenser is to cool the high pressure and superheated refrigerant vapor discharged from the refrigerant compressor into a liquid refrigerant, and its heat is taken away by the cooling water, which makes The refrigeration process carry out continuously.

3. Evaporator: Evaporator is the main heat exchange component of refrigerator air dryer. Compressed air is forced to cool in the evaporator. Most of the water vapor is cooled and condensed into liquid water to drain out of the machine, thus drying compressed air. Low-pressure refrigerant liquid changes into low-pressure refrigerant vapor in evaporator and absorbs heat around it during the phase transformation process, thus cooling compressed air.

4. Thermal expansion valve (capillary): Thermal expansion valve (capillary) is the throttling mechanism of refrigeration system. In the cold dryer, the supply of the refrigerant for evaporator and its regulator are realized by throttling mechanism. The throttling mechanism enables refrigeration to enter the evaporator from high temperature and high pressure liquid.

5. Heat exchangers: Most refrigerator air dryer have heat exchangers. Heat exchangers are heat exchangers between air and air. The main function of the heat exchanger in the dryer is to "recover" the cooling capacity carried by the compressed air cooled by the evaporator, and use this cooling capacity to cool the compressed air at a higher temperature which carries a large amount of water vapor.