Research On 3D Numerical Simulation And Structural Parameter Optimization Of Steam Ejector

In the production process of thermal power plant,there has always been the problem of low thermal energy utilization rate,so how to ensure the use of low quality heat energy under the premise of stable heating,improve the thermal energy utilization rate of thermal power plant,to achieve the maximum energy utilization,has become the most significant chal enge for the production and development of thermal power plant.There is a simple fluid machine cal ed steam ejector,whose working process does not require mechanical energy consumption.It takes steam of higher temperature and pressure as working fluid to suck steam of lower temperature and pressure,and mixes the two to form steam of moderate temperature and pressure,which can be used to heat the circulating water of heat network.In this way,low quality heat energy can be ful y utilized to reduce the energy consumption of the unit,so as to improve the power supply capacity of the thermal power plant.In the case of given working parameters,the steam ejector is modeled.The built model is a threedimensional model,and the numerical simulation research is carried out on it.Firstly,the influence of four structural parameters of the steam ejector on its working performance is studied through single factor sensitivity analysis,and then the optimization algorithm is used to optimize its structural parameters,so as to improve its working performance.Firstly,the main structure and basic principle of steam ejector are introduced.The ejection coefficient is obtained by Sokolov’s method of gas dynamic function under given working conditions,and then the parameter values of each part of the steam ejector are obtained by design.Secondly,CREO software was used to establish a three-dimensional geometric model,and WORKBENCH software was used for grid division and numerical simulation.Then,the influence of four structural parameters of steam ejector nozzle outlet diameter,nozzle expansion section length,mixing chamber contraction section length and mixing chamber throat length on its ejection coefficient was analyzed by FLUENT processing results.The analysis results show that there is an optimal value for each of the four structural parameters of the steam ejector to obtain the optimal ejection coefficient,in which the change of nozzle outlet diameter has the greatest influence on the ejection coefficient,followed by the length of the contraction section of the mixing chamber and the length of the expansion section of the nozzle,and the mixing chamber throat length has the least influence on the ejection coefficient compared with the first three parameters.The structural parameters with high ejection coefficients were obtained by 3D numerical simulation.Finally,the simulation data obtained through 3D numerical simulation is analyzed and studied.The quadratic regression orthogonal combination design method is used to process the data,and the functional relationship between the ejector coefficient and the four structural parameters of the steam ejector is constructed.Cuckoo search algorithm and Gauss Cuckoo search algorithm are written in MATLAB,and these two algorithms are used to solve the objective function,so as to obtain the optimal structural parameter value of steam ejector.Then,the 3D numerical simulation of the optimized parameters is carried out.The simulation results show that the ejection coefficient of the steam ejector is increased by 16.06%by the combination of the optimized structural parameters through intel igent optimization algorithm.