The use of external energy to lower a warmer temperature substance or environment to a cooler one is called a refrigeration system. Refrigeration systems are divided into different types: steam refrigeration, air refrigeration, and thermoelectric refrigeration. Steam refrigeration systems can be divided into vapor compression, steam absorption and steam jets. A full refrigeration system consists of the compressor, condenser, expansion valve, evaporator and assorted spare parts.
The compressor is the power behind a refrigeration system, driven by a motor for continuous rotation. In addition to timely extraction of the evaporator vapor in order to maintain low temperatures and low pressures, a compressor is needed for compression of the refrigerant vapor pressure and temperature, thus creating the refrigerant. Refrigerant vapor is compressed into a high temperature, high pressure state, so that the vapor can be further condensed with air or water at normal temperatures to work as the cooling medium.
The condenser is the heat exchange equipment, whose role is use as an environmental cooling medium (air or water). High temperature, high pressure refrigerant from the compressor removes heat from the vapor, which is then cooled and condensed into a high pressure, room temperature refrigerant liquid. Throughout the condensing process, however, the pressure remains at a high, constant level.
After being condensed, the room temperature refrigerant liquid is sent directly into a low temperature scale evaporator, where the pressure is reduced according to saturation pressure and the saturation temperature corresponding principles, thus lowering the overall temperature of the refrigerant liquid. The liquid then goes through a pressure reduction device (throttling components), turning it into a low temperature and low pressure refrigerant, then sends it into an endothermic evaporation component. In normal operations, an air conditioner is most often used as the throttling element capillary.
The evaporator is a heat exchange device. After the throttling of the refrigerant liquid into its evaporated state (steam), the heat of the material to be cooled is absorbed so the temperature drop s in order to freeze food or products. Within the air conditioner, cooling the air around the evaporator cools the air as well as carries out dehumidifying purposes. The lower the evaporating temperature of the refrigerant, the lower the temperature of the object that needs to be cooled. In the refrigerator, the evaporation temperature of a general refrigerant is adjusted to a range of -26 to -20°C, and the temperature of the refrigerant is adjusted to a range of 5 to 8°C in the air conditioner.