System composition

Main components

The refrigeration system is composed of refrigerant and four major parts, namely compressor, condenser, expansion valve and evaporator.

compressor

The compressor is the power of the refrigeration cycle. It is driven by an electric motor to continuously rotate. In addition to pumping out the vapor in the evaporator in time to maintain low temperature and low pressure, it also increases the pressure and temperature of the refrigerant vapor through compression to create a The conditions for transferring the heat of the steam to the external environment medium. That is, the low-temperature and low-pressure refrigerant vapor is compressed to a high-temperature and high-pressure state, so that normal temperature air or water can be used as a cooling medium to condense the refrigerant vapor.

Condenser

The condenser is a heat exchange device, which uses the ambient cooling medium (air or water) to take away the heat of the high-temperature and high-pressure refrigerant vapor from the compressor, so that the high-temperature and high-pressure refrigerant vapor is cooled and condensed into a high-pressure and normal-temperature refrigerant liquid . It is worth mentioning that in the process of the condenser changing the refrigerant vapor into the refrigerant liquid, the pressure is constant, and it is still high pressure.

Throttle element

The high-pressure and normal temperature refrigerant liquid cannot be directly sent to the low-temperature evaporator. According to the principle of saturation pressure and saturation temperature-the corresponding principle, the pressure of the refrigerant liquid is reduced, thereby reducing the temperature of the refrigerant liquid. Pass the high-pressure and normal-temperature refrigerant liquid through the pressure-reducing device-throttling element to obtain low-temperature and low-pressure refrigerant, and then send it to the evaporator to absorb heat and evaporate. Refrigerators and air conditioners in daily life often use capillary tubes as throttling elements.

Evaporator

The evaporator is also a heat exchange device. The low-temperature and low-pressure refrigerant liquid after throttling evaporates (boils) into vapor in it, absorbs the heat of the material to be cooled, reduces the temperature of the material, and achieves the purpose of freezing and refrigerating food. In the air conditioner, the surrounding air is cooled to achieve the effect of cooling and dehumidifying 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 to -20°C, and in the air conditioner, it is adjusted at 5°C to 8°C.