Investigation Of Steam Ejector Refrigerator Characteristics By CFD

With the popularization of the refrigeration cycle either in the daily life or in the industrial production, the disadvantages of the traditional refrigeration cycles have been more and more prominence. Since the traditional refrigeration cycles consume large energy and make the pollution severe, the investigation of the new-style cycles becomes more and more important. The ejector refrigeration cycle has gained much attention because of its ability to utilize low-temperature thermal energy resources, and its simple structure and reliable operation.Until now the design and evaluation of an ejector are usually based on 1-D analysis. There is a limitation on mastering the effects of geometric parameters of an ejector on its entrainment ratio, so it is difficult to improve the Coefficient of Performance of an ejector.In virtue of FLUENT software, simulation of steam ejector was carried out. Through analysis of the simulation results, many relations between ejector COP and operating and structural parameters were mastered. At the same time, we make the comparison with experimental data and numerical results.The main work and results of this paper are given as follows:(1)A CFD mathematic model which was through experimental data for ejector numerical simulation was set up and the compressible flow process in a steam ejector was simulated on the basis of Reynolds-Averaged equations, turbulence viscosity model and gas state equation. The results of simulation and experiments were compared and the CFD mathematic models which can simulate performance of ejector were validated. (2)Relationships between the ejector performance and its operating parameters were analyzed. From the results of simulation, it was shown how the boiler temperature,condenser pressure influence the performance of steam ejector.(3)Relationships between the ejector performance and its structures were analyzed.Changing the distance between steam nozzle outlet and mixing chamber inlet in simulation, it was showed how the distance between steam nozzle outlet and mixing chamber inlet influence the performance of steam ejector.(4)Phenomena occurring in mixing process were analyzed.