Study On The Performance Of Water Vapor Ejector And Its Multi-Factor Analysis

In recent years,the numerical simulation and analysis of the steam injectors in the steam injection pump have been paid more attention.Many ejector models have been established and a lot of numerical simulation and analysis have been done for the ejector performance.The data is very limited,which makes the applicability of the ejector theoretical model and the correctness of the numerical method lack of experimental data support.Therefore,in order to deeply study and fully grasp the performance of the injector,and to provide experimental data for the numerical simulation.Based on the existing experimental platform of small water vapor injection system,replaced the core components the diffuser to experiment,compared numerical simulation results,improved the numerical simulation model.More accurate numerical simulation results are obtained to support the application of numerical simulation results.The experimental data can be sorted out,and the formula of predicting the ejection coefficient can be deduced by using the expansion ratio and compression ratio.The main research work of this paper is as follows:(1)Structure improvement of small water jet experiment system.Mainly for the diffuser structure parameters(diffuser throat diameter),the use of new materials and design to improve the system's vacuum,so that the measurement of experimental data more accurate and credible.(2)After changing the throat diameter of the diffuser,experiments were carried out to analyze the experimental data and find the difference with the simulation results.Based on this,the numerical simulation model was improved.The influence of the operation parameters of the injector on the performance of the injector is verified and the performance of the injector is affected by the operating parameters of the system.(3)The numerical simulation of the wet steam model is carried out.The simulation results of the wet steam model are analyzed.The difference between the wet steam model and the ideal gas model is analyzed by comparing the results of the wet steam model and the ideal gas model.(4)The working steam pressure and the ejector steam pressure are combined to the non-dimensional treatment,and the formulas for predicting the ejection coefficient using the expansion ratio and the compression ratio are found.And the applicability of the formula is calculated by calculating the error rate and the formula of the formula provided in this paper.The experimental results show that the simulation results of the wet steam model are close to the experimental results when the throat diameter of the diffuser is 30mm.The experimental results are in good agreement with the experimental data.For existing experimental systems,whether the diffuser throat diameter is 30 mm or 28 mm has no effect on the operation of the injector performance.The working steam pressure and the ejecting steam pressure are important factors influencing the performance of the ejector,and there is also interaction between them.There is always a set of working vapor pressures and ejecting vapor pressures that maximize the ejection coefficient of a particular injector.The experimental data can be used to find the equation which can be used to estimate the ejection coefficient with the expansion ratio and compression ratio,and the error rate is lower than that of the formula deduced from the previous theory.It is shown that the formula presented in this paper has some applicability in the range of low expansion ratio.The conclusion of this paper has a reference function for the establishment of the numerical simulation model of the steam ejector.It provides a large number of experimental data of the steam ejector and further studies the performance of the ejector.It is significant for the future research of the ejector.