The four main components of industrial refrigeration system are compressor, condenser, throttling element (i.e. expansion valve) and evaporator.
1. Compressor
The compressor is the power of the refrigeration cycle. It is driven by the motor and rotates continuously. In addition to extracting the steam in the evaporator in time to maintain low temperature and low pressure, it also improves the pressure and temperature of the refrigerant vapor through compression, creating conditions for transferring the heat of the refrigerant vapor to the external environmental medium. That is, the low-temperature and low-pressure refrigerant vapor is compressed to the high-temperature and high-pressure state, so that the refrigerant vapor can be condensed with normal temperature air or water as the cooling medium.
2. Condenser
The condenser is a heat exchange equipment. Its function is to use the environmental cooling medium (air or water) to take away the heat of the high-temperature and high-pressure refrigeration steam of the self cooling compressor, so as to cool and condense the high-temperature and high-pressure refrigerant steam into a refrigerant liquid with high pressure and normal temperature. It is worth mentioning that in the process of changing refrigerant vapor into refrigerant liquid, the pressure of the condenser remains unchanged and is still high pressure.
3. Throttling element (i.e. expansion valve)
The refrigerant liquid with high pressure and normal temperature is directly sent to the low-temperature scale evaporator. According to the principle of saturation pressure and saturation temperature – correspondence, reduce the pressure of the refrigerant liquid, so as to reduce the temperature of the refrigerant liquid. The refrigerant liquid with high pressure and normal temperature is passed through the pressure reducing device throttling element to obtain the refrigerant with low temperature and low pressure, and then sent to the evaporator for endothermic evaporation. Capillary tubes are often used as throttling elements in refrigerators and air conditioners in daily life.
4. Evaporator
The evaporator is also a heat exchange device. The throttled low-temperature and low-pressure refrigerant liquid evaporates (boils) into steam, absorbs the heat of the cooled material, reduces the material temperature, and achieves the purpose of freezing and refrigerating food. In the air conditioner, the surrounding air is cooled to cool and dehumidify the air. The lower the evaporation temperature of the refrigerant in the evaporator, the lower the temperature of the object to be cooled. In the refrigerator, the evaporation temperature of the general refrigerant is adjusted at -26 C ~-20 C, and is adjusted to 5 C ~8 C in the air conditioner.