Study On Numerical Simulation And Structure Optimization Of Ejector Through Fluent

The ejector is an important process unit. It's widely used in the field of energy and power, petrochemical, metallurgy, light textile, refrigeration and industrial thermal. The fundamental nature of the ejector can increase the fluid pressure without direct consumption of the mechanical energy. The ejector structure is simple, but the internal flow field is very complex including the interaction of shockwave, viscous interference, boundary layer and shear layer. Most of the design theories have a large margin of error by using semi-empirical method. The research method of numerical calculation has developed since 90s. By numerical analysis, you may carry on the exhaustive analysis to the working process of ejector and you may optimize and design the overall performance of ejector.This paper is aimed at miniature ejector and large-scale ejector. In terms of its structural size, the research is about the injection performance influence by work imports, the injection import and the mixture chamber length. On the operating conditions, I analysis performance influence to ejector by researching working pressure, injection pressure as well as outlet pressure. Make the preliminary discussion on optimization design to its structure and the operating conditions.By analysis interior flow field of miniature ejector, we obtain the variation of injection coefficient along with structure parameters. When the outlet diameter is less than 6mm, the injection coefficient increases along with the outlet diameter increases. When the outlet diameter is 6~7mm, the injection coefficient has the optimum value. To this miniature ejector, the optimal length of the cylindrical mixture chamber is 4.4~5.6 times than its diameter. The change rule of work import diameter and the injection import diameter is similarity. It appears to have a second-degree parabola relation.By analysis large-scale ejector and simplify the three-dimensional structure, we build model by two-dimensional structure. The influence of working condition and size structure to operating performance are researched. The influence tendency of injection performance is similar along with the size change of fluid outlet, mixture chamber diameter and working import. Along with size enlargement, the injection performance improves gradually. When the size increases to a certain value, "The Middle slow zone" is appeared. To the size of fluid outlet, "The Middle slow zone" is 90~120mm. To the size of mixture chamber diameter, it is 60~90mm. To the size of working import, it is 70~90mm. In the range of 180 ~ 250mm, the length change of mixture chamber is little to the influence of injection coefficient. Regarding the nozzle, the variation of nozzle outlet diameter and throat diameter is similar. The injection coefficient increases along with the structure size to reduce. The work current capacity increases. The influence of ejector performance to the absorption chamber is just opposite. According to data analysis, its optimized size should respectively be 22~38mm, 18~24mm.