Refrigerant oil is a key component in the refrigeration system. It not only acts as a lubricant, but also helps cool the compressor components and removes wear particles generated during operation. However, during use, refrigerant oil may be affected by various factors and deteriorate, resulting in a decrease in its performance, which in turn affects the efficiency and life of the entire refrigeration system.
Main reasons for refrigerant oil deterioration
Water mixing: Once air penetrates into the refrigeration system, the moisture in the air will come into contact with the refrigeration oil and mix into it. In addition, if the refrigerant contains a lot of water, it will also cause water to enter the refrigeration oil. The mixing of water will not only reduce the viscosity of the refrigeration oil, but may also cause corrosion to metal parts. Especially in Freon refrigeration systems, the presence of water may also cause "ice plugging", that is, water freezes and blocks the pipeline, affecting normal operation.
Oxidation: When the refrigerant oil works in a high temperature environment, such as when the exhaust temperature of the compressor is high, the refrigerant oil is prone to oxidation, especially those refrigerant oils with poor chemical stability, which are more likely to deteriorate. Over time, the oxidized refrigerant oil will form residues in the oil, which will deteriorate the lubrication of key parts such as bearings. In addition, the mixing of contaminants such as organic fillers or mechanical impurities will also accelerate the aging or oxidation process of the refrigeration oil.
Mixing of refrigeration oil: Mixing of refrigeration oils of different brands may cause changes in their viscosity and even destroy the oil film, thereby damaging the bearings. If the anti-oxidation additives contained in the mixed refrigeration oil are of different properties, these additives may react chemically to form precipitates, thereby affecting the lubrication effect of the compressor. Therefore, in practical applications, mixing different types of refrigeration oil should be avoided.
Impurities in refrigeration oil: After long-term use, various impurities such as metal chips, dust or other contaminants may accumulate inside the refrigeration oil, which will affect its performance.
How to judge whether the refrigeration oil is deteriorating
High-quality refrigeration lubricants should be pure, usually light yellow or colorless and transparent. However, after a period of use in the compressor, the color of the refrigeration lubricant will gradually deepen and the transparency will decrease, which is one of the manifestations of deterioration. Deteriorated refrigeration lubricants not only greatly reduce the cooling and lubrication effects, but may also generate carbides during the operation of the compressor, leading to blockage of the refrigeration system.
Paper drop method: prepare a clean white paper, take a small amount of refrigerant oil from the compressor shell, and drop it on the white paper. After a period of time, observe the color of the oil droplets on the white paper. If the oil droplets are light in color and evenly distributed, it means that the refrigerant oil is of good quality and can continue to be used; on the contrary, if there are dark spots or ring marks on the white paper, it means that the refrigerant lubricant has deteriorated or contains too many impurities and needs to be replaced.
Comparison method: take some unused refrigerant lubricant and put it into a clean glass test tube or measuring cylinder for a period of time as a control sample. Then take out the refrigerant lubricant to be tested from the compressor and pour it into another container for visual comparison. If the color and transparency of the two are similar, it means that it has not deteriorated; if there is a significant difference, such as turning into an orange-red or reddish-brown turbid state, it means that the refrigerant lubricant has deteriorated and must be replaced with new refrigerant oil to ensure the normal operation of the system.
Through the above methods, we can more accurately judge whether the refrigerant oil has deteriorated, take timely measures to maintain the refrigeration equipment, and ensure its long-term stable operation.
