| 摘要 |
PURPOSE:To prevent an oxidation deterioration of a refrigerating compressor oil by monitoring a quantity of a noncondensable air in a refrigerant and controlling a viscosity decrease of said oil. CONSTITUTION:In case said oil of polyalkylene glycol system is oxidized by the local overheating, distinct variation in property is not observed comparing with mineral oil, but a light difference in an air quantity relating to the viscostity is caused due to the severe local overheating, and the deterioration of the oil performance is though to be influenced remarkably by said difference. As the result of various examinations, the quantity of the noncondensable air (NCA value) in refrigerant is measured, and when such NCA value is suppressed to <=1.0vol%, the variations in color shade and viscosity in accordance with the deterioration due to oxidation can be suppressed within a tolerance value (<=10% of the first value). In this way, the deterioration of the refrigerating compressor oil due to oxidation can be prevented. |
