How much do you know about freezing oil
Although the refrigerating oil is only a small material, if you accidentally use inferior products, you can even burn the machine. I believe that many colleagues have often encountered it. Even if the compressor is not burned directly, the compressor is corroded, the noise is increased, and the cooling efficiency is also significantly reduced. The technical parameters involved in refrigeration oil are also relatively extensive and complex. Engineers come to sort out for us.
Author: Hello! I understand that many users are troubled by various problems when using refrigeration oil, so I hope to get some technical help from you.
Engineer: I am honored.
Author: I heard that if there is a problem with the refrigerating oil, it may cause "burning". What is the cause?
Engineer: What we call "burning machine" is really the compressor being burned. There are many reasons for this phenomenon, and the insufficient viscosity of the refrigerating oil is one of the reasons. We all know that the refrigerating oil has a certain viscosity to keep the friction surface of the moving parts in a good lubrication state, which can take away part of the heat from the compressor and play a sealing role. Generally speaking, refrigerating oil has to work under two extreme temperature conditions: the temperature of the compressor discharge valve can be as high as 150 degrees, and the temperature of the expansion valve and evaporator can be as low as -40 degrees. Such a working environment determines that it needs to have good viscosity-temperature characteristics. If the viscosity of the refrigerating oil is not enough, it will cause the compressor bearings and cylinders to wear more and the noise will increase, at the same time the cooling effect will be reduced, and the service life of the compressor will be shortened. .
Author: That's it.
Engineer: Not only is the viscosity problem, the pour point is also an indicator that may cause "burn-in". As mentioned earlier, the working temperature of the compressor has a wide range of variation. Therefore, in order to ensure that the role of the lubricating oil can be played normally, it is generally required to maintain good mobility at low temperatures. Therefore, the pour point should generally be 10 degrees lower than the freezing temperature, and the viscosity-temperature characteristics should also be good, so as to ensure that the refrigerating oil can return to the compressor from the evaporator smoothly in a low temperature environment. If the pour point of the refrigerating oil is too high, it will cause the oil return to be too slow, and it is easy to "burn the machine". In addition, the flash point of refrigerating oil is too low to bring certain dangers.
Because the general refrigeration oil is relatively volatile, too low flash point will increase the amount of oil in the refrigeration cycle, increase the loss and increase the cost, not to mention, what is more serious is that it will increase the risk of combustion during the process of compression and heating. Possibility, so the flash point of refrigerating oil is required to be more than 30 degrees higher than the refrigeration exhaust temperature
Author: It seems that refrigeration oil really has a lot of professional technical indicators. If you don't understand these, you really have no choice. I often hear a word from some users: "corrosion". How do people usually say "corrosion compressor" occurs, and how can we avoid it?
Engineer: The process of corrosion is more complicated, and there are many chemical reactions in it. I will briefly introduce it. Since moisture freezes in the evaporator, it will affect the refrigeration efficiency. Once in contact with the refrigerant, it will accelerate its decomposition and corrode equipment. Therefore, if the moisture in the refrigerating oil exceeds the standard, under the catalysis of the metal, the moisture in the refrigeration system will react with the refrigerant, naturally generating hydrochloric acid and hydrofluoric acid, which will cause corrosion to the compressor. Corrosion will greatly shorten the life of the compressor, or even scrap it quickly, causing considerable losses to users.
Author: It seems that "corrosion" is no less harmful than "burning machine." Is there any other cause of corrosion?
Engineer: Yes, for example, the chemical stability of the refrigerating oil is insufficient, and the thermal stability is too low. As we said earlier, the compressor's z* high compression temperature is very high, which can reach 130-160 degrees. In such a high temperature state, the refrigerating oil will be heated and decomposed into carbon deposits, causing the compressor to wear. The oil decomposition products will chemically react with the refrigerant to reduce the cooling effect, and the acidic substances produced will cause strong corrosion to the compressor.
Author: Well, it seems that they are all principles we need to understand. These technical indicators should be enough to help us weigh a benchmark for the quality of a refrigeration oil. In addition to the above, are there other technical indicators that need to be paid attention to?
Engineer: Hmm...the content of paraffin also needs attention. During use, the mixture of refrigerant and mineral oil-based refrigerating oil will cause insoluble matter such as paraffin to precipitate, and precipitate at a temperature higher than the freezing point. If the content of paraffin in the refrigerating oil is too high, it will cause the cooling system and refrigeration pipelines The blockage is very dangerous.
Author: So we need to pay attention to these technical indicators, according to these indicators to judge and purchase refrigeration oil.
Engineer: Indeed, the analysis of various principles will look more professional, so the average consumer can make judgments based on several important indicators when purchasing, and avoid unnecessary losses as much as possible.
Through this consultation, we can easily sort out some key words: insufficient viscosity of refrigerated oil, excessive water content, excessive paraffin wax content, insufficient chemical and thermal stability, low flash point and high pour point, etc. These indicators The above deviations are the main factors that usually cause application failures. The use of refrigerating oil is not a matter of course. Once a mistake occurs in the purchase process, it may cause major losses. It seems that refrigerating oil may seem like a trivial matter, but in fact it should not be underestimated. It can be described as a "section" that cannot be ignored.
