As the core equipment in industrial production, screw air compressor mostly adopts oil lubrication and cooling system. The oil not only assumes the role of lubrication, but also responsible for heat dissipation, sealing, cleaning and anti-corrosion and many other key tasks. So, what is the actual replacement cycle of screw air compressor oil? In fact, "oil life" is not a fixed value, but by multiple operating conditions and environmental factors. The following is a systematic analysis of the main factors affecting the screw compressor oil life.

1. Effect of exhaust temperature

The aging rate of the oil is closely related to the compressor exhaust temperature. **If the constant exhaust temperature of an oil-injected screw air compressor is lowered by 8 to 10 degrees Celsius for every 8 to 10 degrees Celsius, the life of the oil can be approximately doubled. **This is one of the reasons why many host manufacturers emphasize the control of exhaust temperature.

2. Exhaust pressure and partial pressure of oxygen

The rate of oil oxidation varies with exhaust pressure and partial pressure of oxygen in the air.Single-stage oil-injected screw compressor discharge pressure from 0.3 ~ 1.3MPa to enhance the high-pressure machine due to the exhaust temperature and oxygen partial pressure is higher, the oil oxidation rate is accelerated, the life of a significant reduction in the. Examples:Low pressure machine with 0.3MPa exhaust pressure, lubricant life can be extended 3~5 times than 1.3MPa high pressure machine.

3. Effects of differences in compressed gases

• compressed air: Conventional oil life is directly related to operating conditions.
• Compressed nitrogenThe theoretical life of the lubricant is significantly longer than that of comparable compressed air models due to the lack of oxygen involved and the lack of oxidation of the lubricant.
• carbon dioxide CO2 compression: The acid value in the lubricant is more likely to exceed the standard, leading to faster deterioration and shorter actual life.

4. Differences in levels and structure

• Two-stage compression injectors: In addition to improved energy efficiency due to lower partial pressure and temperature of oxygen at all levels, oil life is approximately twice as long as a single-stage model of the same type.
• High Pressure Ratio Single Stage Machine: High exhaust gas temperatures due to single-stage high-pressure ratios lead to oil aging and shortened life.

5. Modes of operation of equipment

• Frequency Injector Screw Air Compressor: The lower exhaust gas temperature during the inverter operation phase results in a lower shear burden on the lubricating oil than in normal capacitively regulated models, resulting in a longer actual life. The oil life also fluctuates under different inverter control strategies.
• Enhanced cooling design: Some manufacturers reduce the exhaust temperature by increasing the fan and optimizing the air ducts, which can also reduce energy consumption and extend the life of the oil to achieve energy saving and emission reduction.

6. Differences in types of equipment

• Centrifugal CompressorsThe oil replacement cycle is generally much longer than that of oil-injected screw compressors because the lubricating oil is subject to less heat and shear due to the difference in structure and working principle.