Refrigeration oil is a core lubricating medium for refrigeration compressors. It must work stably under two extreme conditions: the low-temperature evaporation end at approximately -40℃ and the high-temperature compression end above 100℃. Its viscosity parameter directly determines the operating state and service life of the compressor.
Insufficient viscosity of refrigeration oil can trigger a series of chain failures: first, the oil film cannot form an effective protective layer on the surfaces of precision components such as bearings and cylinder blocks, resulting in direct friction of metal parts. This increases the wear rate by 3–5 times and raises the equipment operating noise by 10–15 decibels. Second, lubrication failure will increase the compressor's operating resistance, leading to an 8%–12% rise in energy consumption and a decline in refrigeration cycle efficiency. The direct manifestations include reduced cooling capacity and slower cooling speed. Long-term operation under such conditions will shorten the compressor's service life by 40%–60%.
What is more serious is that when the viscosity is too low to dissipate the heat generated during compression, the internal temperature of the compressor will keep rising. When the temperature exceeds the tolerance threshold of insulating materials, it will cause winding burnout, a fault commonly known as "compressor burnout", which directly leads to compressor scrapping.
Therefore, selecting the appropriate refrigeration oil viscosity for the working conditions is a key prerequisite for ensuring the stable operation of the refrigeration system.