The role of refrigerant in air-cooled chillers

　　【】The refrigerant itself circulates continuously in the refrigeration system, and then realizes refrigeration through its own state changes. The refrigerant absorbs the heat of the cooled medium in the evaporator and vaporizes, and transfers the heat to the surrounding air or water in the condenser to condense. When the air-cooled chiller refrigeration cycle system is running, the refrigerant is also inseparable. The refrigerant flows continuously in the air-cooled chiller circulation system, and its state is constantly changing. Therefore, the state of the refrigerant in each position of the air-cooled chiller refrigeration cycle system is different. . So, what role does refrigerant play in air-cooled chillers?

　　1. The change of refrigerant in the air-cooled chiller refrigeration compressor

　　 The refrigerant enters the suction port of the compressor from the end of the air-cooled chiller evaporator , And complete the process of compressing refrigerant vapor into superheated vapor in the refrigeration compressor, and the pressure is also increased from the evaporating pressure to the condensing pressure. Since the compression process of the compressor is completed instantaneously, the refrigerant vapor at this time will not exchange heat with the outside world, which is called the adiabatic compression process.

　　2. The change of refrigerant in the condenser of the air-cooled chiller

　　 After the superheated steam enters the condenser of the air-cooled chiller, the pressure condition does not change, so It will first emit a part of the heat, so that the superheated vapor of the refrigerant is cooled into saturated vapor. Because it is still under isothermal conditions at this time, the saturated vapor will continue to emit heat and condense and continuously produce saturated liquid. The longer the condensation time, the more saturated liquid will be, and the saturated vapor will decrease. The end result of z* is: all refrigerant vapor is condensed into saturated liquid.

　　3. The change of refrigerant in the throttle element of the air-cooled chiller

　　 Since all the refrigerants have become saturated liquid, when the saturated liquid refrigerant flows through the air-cooled When the throttling element of the chiller, the condensation pressure drops to the evaporation pressure, and the temperature drops from the condensation temperature to the evaporation temperature. The refrigerant flowing out from the outlet of the throttle element becomes a two-phase mixed state with about 80% of liquid and about 20% of gas. A small amount of vapor is generated due to the flash gas that appears due to the expansion of the liquid due to the pressure drop.

　　4. The change of refrigerant in the evaporator of the air-cooled chiller

　　 When the refrigerant enters the evaporator of the air-cooled chiller, it is absorbed by the cooling medium. With heat and constant evaporation, the refrigerant is constantly vaporized under constant temperature conditions, so that there is less and less liquid, but more and more vapor. When the refrigerant liquid is completely vaporized and becomes saturated vapor, it will return to the compressor suction port of the air-cooled chiller to recirculate the above changes.