Influence of oil injection on performance of screw compressor

The impact of oil injection on the performance of screw compressors is mainly reflected in the following aspects：

1. The cooling effect is significantly improved
   The micro-droplet oil mist formed by oil injection mixes with the compressed gas, quickly absorbs the compression heat through the huge heat exchange area, effectively reducing the exhaust temperature. For example, in cleaning scenarios in the electronics industry, oil-injected screw compressors can control the exhaust temperature within a reasonable range to avoid damage to precision components from high temperatures. At the same time, the improvement of cooling effect reduces heat loss during the compression process, makes the compression process closer to isothermal compression, reduces compression work, and improves insulation efficiency.
2. Significantly enhanced sealing performance
   There are many leakage channels inside the screw compressor, and most of these channels are long and narrow gaps. The injected oil forms an oil film in the gap, which greatly enhances the sealing effect and significantly reduces gas leakage. When processing light component gases, the sealing effect of the lubricating oil makes the volumetric efficiency better exerted and ensures stable operation of the compressor.
3. Lubrication optimizes mechanical structure
   Oil injection replaces the synchronous gear in the dry screw compressor, and the male rotor directly drives the female rotor, simplifying the transmission structure. At the same time, the injected oil is the same as the bearing lubricating oil, and there is no need for a complex sealing device to isolate the gas and the lubricating oil, which makes the rotor support bearing spacing smaller, the rotor rigidity is significantly improved, and deformation is reduced. This optimization reduces mechanical wear, extends equipment life, and reduces maintenance costs.
4. Significant noise reduction effect
   The injected viscous oil mist absorbs and dampens sound energy and sound waves, and can reduce noise by 10-20 decibels. In scenarios such as the electronics industry that have strict environmental noise requirements, the low-noise characteristics of oil-injected screw compressors help improve the working environment and reduce noise pollution.
5. Balanced optimization of efficiency and energy consumption
   The amount of oil injected directly affects the efficiency and energy consumption of the compressor. Appropriate amount of oil injection can reduce leaks and improve cooling, thereby improving volumetric efficiency and adiabatic efficiency. However, excessive oil injection will lead to increased oil stirring losses, which will reduce mechanical efficiency. In practical applications, when the oil-gas ratio is controlled at 1%-2%, the comprehensive efficiency of the compressor is the highest. For example, a smaller value is taken when the exhaust pressure is low, and an appropriate increase when the exhaust pressure is high to achieve the best balance between efficiency and energy consumption.
6. Simplified structure and improved reliability
   The oil injection design makes the screw compressor simpler in structure, reduces wearing parts, and eliminates the need for backup equipment. Compared with oil-free screw compressors, oil-injected compressors eliminate complex oil seal systems, extend maintenance intervals, and significantly improve reliability. In practical applications, the oil-injected screw compressor can work continuously for several years, meeting the high requirements for equipment stability in the electronics industry.
7. Improved adaptability and flexibility
   The oil-injected screw compressor uses slide valve technology to adjust the ratio of air volume to capacity, which can adapt to more working conditions. For example, in variable frequency screw compressors, oil injection characteristics are closely related to operating performance. By installing an oil amount adjustment device, the compressor can maintain optimal performance at different speeds, meeting the flexible needs for compressed air parameters in scenarios such as cleaning in the electronics industry.