Structural Improvement And Performance Increase Of Small-scale Steam Ejection Experimental System

With the improvement of people’s energy conservation awareness, the steam ejector which takes advantage of the industrial waste heat and solar energy become increasingly popular, therefore, researches on the steam ejector have an important significance. However, because of the complicated nature of flow structure and mixing process within a steam ejector and the relatively low entrainment ratio, it is very essential for us to enhance the performance of the steam ejector. In recent years, numerical analysis of ejector has been paid more attention to, and a lot of work has been done in many aspects. But experimental data from the literature is very limited, it has a negative effect on the applicability of theoretical models and reliability of numerical methods, at the same time, it has restricted the application of numerical simulation results. In addition, most researches are aimed at single variable, there are few researches on multiple factors. In order to in-depth research and comprehensively understand of the performance of the ejector, and to provide experimental data support for the numerical simulation, it is necessary to design and build the steam injection system experimental platform, to do more experimental study on the performance of the jet pump, and optimizing the experimental system to gain more reliable experimental data.The main research studies contained in this paper are as follows:(1)To improve the existing small steam injection experiment system. Aimed at the structure for the diffuser, structural improvement, and optimization of the injector.(2)The models based on the main injector of the experimental system, using computational fluid dynamics (CFD) method, based on ANSYS FLUENT 14.0 computing platform, to simulate the internal flow field of ejector, obtained the experimental results in the center of pressure distribution under different geometric parameters, entrainment coefficient curve and critical pressure. At the same time, using the simulated results put forward proposals for improving the injector.(3)The models based on the main injector of the experimental system, based on ANSYS DesignXplorer computing platform, multivariate analysis for the current ejector, and to give some improvement suggestion on the performance of ejector.This study shows that, in a certain area, with the increase of the diameter of the diffuser throat, the entrainment ratio of ejector showed a tendency to increase. With the rise of entrainment steam pressure, the entrainment ratio of ejector showed a tendency to increase. In addition, under the existing equipment conditions, among operational parameters, the inlet pressure of the primary steam has a greater impact on the entrainment ratio than the inlet pressure of the secondary steam.