在蒸汽压缩循环中，压缩机需要油来防止表面接触、散热、提供密封、防止污染物进入、防止腐蚀，以及处理磨损产生的碎屑。一小部分压缩机油与制冷剂一起在循环部件中循环，而大部分机油留在压缩机中。制冷剂携带的油量通常在制冷系统中循环制冷剂流量的0.5%到1%之间。这意味着，在系统实际运行期间，机油可能会从压缩机中流失，因为机油可能会积聚在热交换器内。 引用:无效

In vapor compression cycles the compressors need oil to prevent surface-to-surface contact, to remove heat, to provide sealing, to keep out contaminants, to prevent corrosion, and to dispose of debris created by wear. A small portion of the compressor oil circulates with the refrigerant through the cycle components, while most of the oil stays in the compressor. The oil amount carried with the refrigerant typically ranges from 0.5 to 1 percent of the refrigerant flow rate circulating in the refrigeration systems. This means that oil might be missing from the compressor because it can accumulate inside the heat exchangers during actual operation of the systems.