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Why Does Not The Screw Chiller Return Oil?
- Oct 27, 2017 -

What is the reason for the poor return of the screw chiller?

If the Screw Chiller bad oil is a very troublesome thing, in general, Screw Chiller back to the poor oil is mainly due to the operation of the process, the oil and refrigerant gas mixture phenomenon The Specifically, in the operation of the refrigeration system, encountering refrigerant and freezer oil miscible solution will cause the refrigerant in the refrigeration compressor with the machine running and the refrigerant in the form of aerosol and droplets into the condenser. If the oil separator is not good or the system design is not good will result in poor separation and poor oil return system problems. Of course, the prerequisite is that you have not used fake oil.

What are the effects of the Screw Chiller poor oil return?

Screw Chiller bad oil return, will lead to a large number of lubricants stay in the evaporator pipeline, when the oil film increases 0.1mm will directly affect the system cooling, on the other hand the machine can not run the oil shortage, need to continue to add lubricants, and This will lead to the system of lubricants accumulate more, resulting in a vicious cycle, increase operating costs, reduce operational reliability. In general, the refrigerant gas flow below 1% of the oil and gas mixture in the system is allowed to cycle.

How to solve the problem of Screw Chiller back to oil?

In the case of

Compressor oil return in two ways, one is the oil separator back to the oil, the other is the return air back to the oil. Oil separator installed in the compressor exhaust pipe, the general can be separated from 50-95% of the run oil, oil return effect is good, fast, greatly reducing the amount of oil into the system piping, which effectively extend the non-return operation time.

The pipeline is particularly long cold storage refrigeration system, full of liquid ice-making system and the temperature is very low freeze-drying equipment, boot ten minutes or even tens of minutes do not return the oil or very little oil back is not surprising, Bad system will appear compressor oil pressure is too low and the problem of downtime This refrigeration system to install high efficiency oil separator can greatly extend the compressor without oil return operation time, so that the compressor safety after the boot without oil return crisis stage The

The oil that is not separated will enter the system, with the refrigerant flowing in the tube to form the oil circulation. Lubricants into the evaporator, on the one hand because of low temperature solubility, part of the lubricating oil from the refrigerant separation; the other hand, the low temperature viscosity, separated from the oil easily attached to the wall of the tube, the flow more difficult. The lower the evaporation temperature, the more difficult it is to return the oil. This requires that the design and operation of the evaporative piping design and return air piping must be conducive to oil return. The common practice is to use a descending piping design and to ensure a greater airflow velocity.

For particularly low temperature refrigeration systems, in addition to the use of high efficiency oil separator, usually also add a special solvent to prevent the oil plugging the capillary and expansion valve, and help back to the oil. At the same time, some people use the air conditioner's built-in oil instead of external oil, the surface is to save costs, but the system from the long-term use of terms, it will only greatly increase operating costs. The efficiency of the system will be getting worse.