Effect of Refrigeration Oils and Sliding Materials on Copper Deposit in a Refrigerant Compressor

摘要

Copper is occasionally deposited as a plate in compressors for refrigerators and air conditioners. The surfaces of sliding bearings and rolling bearings are deteriorated by the copper deposit leading to unfavorable compressor operation. Here, we describe the effects of lubricants, contaminants, and materials on the copper deposit phenomenon, which is investigated on the copper deposit elemental test. Mineral oil and ester oil, used for refrigeration, are evaluated as lubricants. More copper is deposited with mineral oil than with ester oil. Chloride ions are the medium of copper deposit. The saturation level of contaminants, iron chloride, and water in mineral oil is lower than in ester oil. Chloride ions tend to be generated in mineral oil, and the quantity of copper deposit increases according to the amount of contaminants that exceed the saturation level of the oil. Several materials are examined. Materials with high corrosion resistance to chloride are proved to show high performances in preventing copper deposit.