Computational Fluid Analysis Of Compress Refrigeration Ejector

A special ejector has been designed based on compress refrigeration theoretical foundation.It can be applied in industry and agriculture to efficiency improvement.In this paper, the business fluid analysis software Fluent has been used to analyze the whole process of ejector internal fluid by simulating the process parameter and structure parameter.This paper based on the designed ejector modle.Taking ammonia as refrigeration,two dimension axis-ymmetric as object.With the help of ICEM CFD and Fluent to build the mesh and boundary conditions.Then simulate the influence of working fluid pressure Pm, driving fluid inlet pressure Ps and mixed fluid outlet pressure Pd to the performance of ejector.After the research,the optimum operational are chosen to analyze the influence of structure parameter.On the condition of constant process parameters,this paper adjust the dimension of nozzle, mixing chamber and diffuser to simulate the influence of structure parameters by different groups of dimension, which numerical analyzed the dameter of ejector nozzle throat D1 and nozzle outlet D3, the mixing chamber D4, the length of the nozzle outlet position L1 length of diffuser L2 and length of mixing chamber L3 etc.The optimum structure can be found by the simulation analysis.In conclusion,the simulation results show that the working fluid pressure increasing under a certain range will reduce the ejector coefficient;Ejector coefficient will improve when driving fluid pressure increases, but increasing too much can also lead to the excessive consumption of energy, and then reduced the ejector efficiency;The choice of the ejector outlet pressure is also critical for the improvement of the performance of the ejector.It can lead to reflux within the ejector when outlet pressure exceeds the critical value and the ejector coefficient will drop sharply;With the increasing of D3, u will decreases;As the increase of L1 and D2,u will increase first and then decrease;As the increase of L2 and L3,u will be stable;With the increase of D4,u will increase.Not only the operational parameters will affect the performance of ejector, the structure parameters is also quite important.The results also shows that optimization of the ejector structure is important to improve the performance of ejector.