The main function of a refrigeration unit is to transfer heat from a low-temperature object to a high-temperature environment through a thermodynamic cycle, thereby obtaining cooling capacity and achieving cooling or maintaining a low-temperature environment. It is widely used in homes, industry, commerce, and scientific research, providing necessary low-temperature conditions for food refrigeration, air conditioning, medical preservation, and industrial production.
Essentially, a refrigeration unit is a "heat transporter." Its core function is to utilize the state change of the refrigerant in the system (gas-liquid phase change) to complete the following four key steps in a cycle:
Compression: The compressor compresses the low-temperature, low-pressure refrigerant gas into a high-temperature, high-pressure gas, providing the power for the cycle.
Condensation: The high-temperature, high-pressure gas dissipates heat to the outside in the condenser, cooling and liquefying into a high-pressure liquid.
Throttling: The expansion valve reduces the pressure and temperature of the high-pressure liquid refrigerant, forming a low-temperature, low-pressure wet vapor.
Evaporation: The low-temperature, low-pressure refrigerant absorbs heat from the object being cooled in the evaporator, vaporizing itself to achieve the cooling effect.