Why Oil leakage of refrigerated chiller

The fault phenomenon is as follows:

1. No trace of oil can be seen in the oil separator. Now the oil does not gather in the condenser, but enters the evaporator through the expansion valve. The oil will stick to the evaporator heat exchange copper tube, making the evaporation effect of the evaporator poor, causing low pressure in the evaporator, and at the same time making the suction superheat of the compressor very low so that the refrigerant liquid is directly sucked in. At the same time, the compressor exhaust temperature is very low, and the oil and refrigerant are still unable to be separated. Such a vicious cycle will cause all the oil to gather in the evaporator. The compressor makes a huge noise due to insufficient oil supply, and even the unit oil separator oil level alarm stops.
2. No trace of oil can be seen in the oil separator. All the oil reaches the condenser with the exhaust. If the water temperature continues to be low, all the oil will gather in the condenser and cause oil blockage in the expansion valve. Due to insufficient liquid supply in the evaporator, the pressure begins to decrease until the low pressure alarm stops.

The above is the so-called oil leakage phenomenon. The main reason is that the chilled water temperature is low and the exhaust temperature is low.