Why does a refrigerator have high exhaust pressure and high oil pressure when the load is very low?
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The propylene twin-screw refrigeration machine in our unit exhibits high exhaust pressure and high oil pressure under light load conditions. Specific parameters: Suction pressure: 158 kPa (absolute pressure), Suction temperature: -15 degrees Celsius. Exhaust pressure: 1638 kPa, exhaust temperature: 66 degrees Celsius. Oil pressure: 1914 kPa, oil temperature: 44 degrees Celsius. Load: 7%. The cooling water system is operating normally. What’s the reason for that, please?
Correction: The twin-screw refrigerators using ethylene (not propylene) in our facility experience high exhaust pressure and high oil pressure when the load is very low. Specific parameters: Suction pressure: 158 kPa (absolute pressure), Suction temperature: -15 degrees Celsius. Exhaust pressure: 1638 kPa, exhaust temperature: 66 degrees Celsius. Oil pressure: 1914 kPa, oil temperature: 44 degrees Celsius. Load: 7%. The cooling water system is functioning properly, and the refrigerant is ammonia. What’s the reason for that, please?
The oil drain pipe is positioned too high, preventing the oil inside from being completely drained
Could you explain in detail whether it could be due to the oil separator?
The pipeline from the evaporator to the salt water tank – the oil drain port is located there. Is the oil drainage position too high, in my opinion?
Thank you very much. The reason has been identified: the two twin-screw refrigeration units share one evaporator, with one unit being used for processing while the other maintains production operations. During the processing, that unit was not isolated with a blind flange, resulting in nitrogen entering the refrigeration machine that was maintaining production operations. In other words, the non-condensable gas causes high pressure.