What Is The Performance Of The Refrigeration Oil?
Thermal Stability Thermal stability is generally measured by the flash point of the refrigeration oil. The flash point is the temperature at which the vapor of the refrigerating machine oil flashes after a fire. The flash point of the refrigerating machine oil must be higher than the exhaust temperature of the compressor.
Fuidity The refrigerating machine oil should have good fluidity at low temperature. In the evaporator, the fluidity deteriorates due to the low temperature and the viscosity of the oil. When the temperature reaches a certain temperature, the refrigerating machine oil stops flowing. The temperature at this time is called the freezing point of the oil. . The refrigerating machine oil of the refrigerator requires a low freezing point, and in particular, the cryogenic refrigerator is important for the freezing point of the oil. Otherwise, the fluidity is reduced, which affects both the heat transfer of the evaporator and the lubrication of the machine.
Solubility The various refrigerants are not compatible with the refrigerating machine oil. They are roughly classified into three categories: one is insoluble to each other, the other is infinitely dissolved, and the other is intermediate between the two.
Cloud point The temperature at which the refrigerating machine oil begins to precipitate paraffin (oil becomes turbid) is called the cloud point. When there is refrigerant, the cloud point of the refrigerating machine oil will decrease.
In addition, fully enclosed and semi-closed refrigerators have certain requirements on the electrical breakdown voltage of the refrigeration oil, and are generally required to be above 25KV.