Low temperature chilled lubricant selection considerations

When you use a cryogenic chilled, you definitely want to know about all aspects of the cryocooler. But one of the things that needs everyone’s attention is that the type of lubricant for the chilled is chosen because there are many influencing factors. When you choose, you need to choose carefully.

There are many types of compressors for cryogenic chilled. Generally, pistons, screws, and centrifugals are commonly used. Among them, the piston type and screw type compressor are in direct contact with the lubricating oil and the refrigerant, so when selecting the lubricating oil, attention should be paid to the mutual influence of the refrigerant. Secondly, the centrifugal type is only used to lubricate the rotor bearing. It is recommended to choose according to the load and the speed when selecting.

In addition to the compressor, it is also possible to select the lubricating oil according to the type of refrigerant, because the refrigerant and the lubricating oil are mutually influential, it should be noted that the selected refrigerant and lubricating oil cannot dissolve each other, and the low-temperature chilled is recommended. The viscosity of the lubricating oil should be as high as one level higher than the refrigerant. It is necessary to ensure that the lubricating oil can be lubricated after dilution, so that the operation of the low temperature freezer will not be affected.

Another option for cryogenic chilled is the evaporation temperature of the refrigerant. Generally, the corresponding freezing point lubricating oil is selected according to the evaporation high temperature and low temperature of the chilled. When freon is used as the refrigerant, the condensation point of the lubricating oil is required. Above the evaporation temperature, if it is ammonia refrigeration, the freezing point will be lower than the evaporation temperature.

Of course, if the working conditions of the cryogenic chilled are different, the lubricating oil is also a little different. If the large, medium, and heavy load is large, try to choose a lubricant with a relatively large viscosity. For a small one, you can choose a lower viscosity.

The choice of lubricating oil for cryogenic chilled is closely related to the operation of cryogenic chilled.