scroll compressor, oil-injected, sealing, lubrication, CFD
Oil-injected screw compressor has been used in various industries. After decades of continuous research efforts by research teams around the world, the computer tools for rotor profile design, thermodynamic analysis, CFD/CAE calculation, and moving grid generation have been well developed and widely employed in design works. With assistance from the computer tools in performance simulation, designers could clearly understand internal phenomena of a screw compressor, as a reference for performance optimization design, and systematically carry out research works. One important issue inside an oil-injected screw compressor is about oil distribution. Different oil-injected positions and quantities cause different oil distribution inside the compressor. Therefore, the effects of oil sealing and lubrication change. Designers must understand how oil distribution is to deal with oil issues. In this study, CFD analysis was done with dynamic grid technology. Basic performance of screw compressor was calculated and compared with experiment data. Besides, three CFD models with different oil-injected paths were designed and analyzed. The influence of varying oil-injected conditions on oil distribution near contact line, sealing lines, blow holes, and end sides of inlet and outlet are shown in this study. They are used to explain how volumetric efficiency is affected. Especially for oil distribution near contact line, it not only affects volumetric efficiency, but also acts on the lubrication as rotor meshing.