Benefits of regular oil change in chillers

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Benefits of regular oil change for chillers: 1. Screw compressors generally require their first oil change during maintenance after around 3,000 hours of operation. Thereafter, the refrigeration oil is replaced every 5,000 hours. 2. Refrigerant oil performs five functions in a screw compressor: sealing, lubrication, hydraulic assistance, cleaning, and cooling. 3. As the freezing oil is used for an extended period, its viscosity and lubricating properties gradually decline. This results in poor sealing at the contact surface between the screws, allowing high-temperature, high-pressure Freon gas to leak to the low-pressure side; the main consequences are a decrease in the cooling capacity of the unit and an abnormally high suction pressure in the compressor. 4. After long-term use, the lubricating properties of the refrigerant oil decline, which is manifested mainly by increased noise from the compressor, greater vibration during operation, and a higher operating current for the compressor. The decline in lubrication performance leads to increased resistance during the rotation of the compressor screws, higher operating load on the motor, elevated coil temperatures, and ultimately an increase in the power consumption of the unit. At the same time, the degradation of lubrication performance also accelerates the wear of the screw and rolling bearings, threatening the service life of the entire machine. 5. The hydraulic assist function primarily serves to move the slide valve inside the compressor in order to load and unload it. Over time, impurities accumulate in the refrigeration oil, which can very likely cause blockages in the gaps between the slide valve and the valve chamber; as a result, the valve disc cannot move, and ultimately the compressor is unable to load or unload. 6. Cleaning is primarily achieved through the cleaning components contained within the refrigeration oil; in refrigeration oil that has exceeded its service life, the activity of these cleaning agents drops significantly, resulting in almost no cleaning efficiency. Its hazards mainly lie in the gradual accumulation of dirt on the surfaces of moving parts, which causes the gaps between these parts to gradually become smaller than normal, thereby increasing operational resistance and even leading to jamming. 7. The cooling effect is achieved by the refrigerant oil removing heat as it flows through the components; once its service life is exhausted, the fluidity of the refrigerant oil decreases, and its flow speed over the surface of the components slows down, preventing adequate cooling of those components. 8. In summary, screw chillers must have their refrigerant oil replaced regularly to ensure the proper operation of the unit.