In the chiller operating system, we are more concerned about the refrigerant cycle system of the screw chiller and the chilled water cycle system of the unit.The lubrication system is an object often overlooked by everyone. In fact, the cold water system is also very important for chiller units.
The failure of the lubrication part of the chiller is not a problem of the lubrication system itself, but it will eventually lead to the failure of the system.For example, the selection of the piston ring structure at the cylinder, improper processing and assembly can cause a large amount of oil running, and abnormal leakage at the shaft seal will cause the oil level in the crankcase to drop significantly, which will lead to the air pumping phenomenon of the oil pump. It should also be checked, analyzed and judged from the operating condition of the screw chiller, whether there is abnormal vibration, sound, heat and leakage, etc. For specific inspection, please refer to the following methods:
1. The system is seriously leaking.
2. The oil pump has been working for a long time, and the pump is severely worn, and the internal leakage is significantly reduced due to excessive internal leakage.
3. The temperature of the oil in the crankcase is too low, the viscosity of the frozen lubricating oil is too large, the filter at the inlet of the pump is too dense, the filter element is blocked, and the oil level is too low, which makes it difficult for the pump to suck oil, resulting in air suction.
4. The pressure regulating valve core is stuck in the open position or the spring of the pressure regulating valve fails.
The most common failures of the screw chiller lubrication system are: no pressure on the oil pump, failure of pressure adjustment, and violent swinging of the pressure gauge pointer.Pay attention to the following points in the maintenance of the chiller lubrication system:
1. Pay attention to the oil level, oil temperature and oil pressure during daily inspection.
2. Regularly check the oil quality according to the oil change index specified by the frozen lubricant, and replace or replenish the filtered new oil.
3. During the middle and overhaul, pay attention to check and adjust the end gap of the oil pump, and replace the pump if necessary.The end face clearance of the pump is about 0.03-0.08mm depending on the size and specifications. For specific values, please refer to the relevant assembly technical requirements and factory regulations of the pump.
4. Regularly replace or clean the filter element, pipeline and crankcase.
The technical requirements for the maintenance of the lubrication system of the screw chiller are relatively strong, mainly related to the performance of the compressor main body. It is recommended that the maintenance be performed by a professional to avoid unnecessary losses.