Experimental Investigation Of A Small Steam Injection System And Its Performance

The steam jet refrigeration system is a device using industrial waste heat, solar energy and other low temperature heat source to achieve the cooling effect, in the increasingly tense energy crisis of today, it has very important significance to study and continue to study it. Although the steam jet refrigeration system has many advantages, but traditional compression refrigeration system continues to dominate the refrigeration market. The main reason is that the cooling efficiency of steam jet refrigeration system is low. In order to promote their wider application, enhance the performance of the ejector has become the key point to the prograss of steam jet refrigeration system. In recent years, numerical analysis of the jet was taken seriously, there is a lot of numerical simulation of jet has been taken in flow field, and the influence of operating parameters and structural parameters on jet pump performance. But experimental data from the literature is very limited and difficult to get confirmation of the applicability of theoretical models and reliability of numerical methods, which has restricted the application of numerical simulation results. In order to in-depth research and accurately knowledge of the performance of the ejector, and to provide experimental support for the numerical simulation, it is necessary to design and build a small steam injection system experimental platform and to do more experimental study on the performance of the jet pump.The main research studies contained in this paper are as follows:(1) Design a small small steam injection system for experimental investigation.(2) Using computational fluid dynamics (CFD) methods to check and improve the main jet structure.(3) Processing the main parts and components of the experimental system. Purchase instrumentation, valves and other parts of the small steam injection system to constructed the small steam injection system.(4) Change the operational parameters (working steam pressure, evaporation pressure of the evaporator and back pressure of the ejector) to jet ejector entrainment ratio, drawn the experimental entrainment ratio curve under different operating parameters, and get the critical back pressure of the ejector. Analysis the experimental errors that may exist.(5) Using CFD software ANSYS FLUENT12.0to simulate the internal flow field and pumping performance of steam ejector, and get the entrainment ratio curve and the critical back pressure of numerical simulation under different operating parameters. Compared experimental results with the numerical simulation results, and verify the accuracy and the ability to capture shock of the numerical simulation.The above study demonstrated that, with the rise of working steam pressure, the ejector critical back pressure would also rising, while the entrainment ratio would decreases when it’s in congestion state; with the rise of entrainment steam pressure, the entrainment ratio of ejector showed a tendency to increase; when working steam pressure is high, the use of the ideal gas model assumptions for numerical analysis is reasonable, but when the working steam pressure is lower, this assumption is not necessarily reasonable, so it is need to consider using wet steam model to analyze.