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A Numerical Study on the Performance of a Two-Stage Ejector-Diffuser System

  • Kong, Fanshi (Department of Mechnical Engineering, Andong National University) ;
  • Kim, Heuy Dong (Department of Mechnical Engineering, Andong National University)
  • Received : 2014.11.17
  • Accepted : 2015.04.09
  • Published : 2015.06.30

Abstract

The conventional ejector-diffuser system makes use of high pressure primary stream to propel the secondary stream through pure shear action for the purposes of transport or compression of fluid. It has been widely used in many industrial applications such as seawater desalination, solar refrigeration, marine engineering, etc. The present study is performed numerically to study the performance of a two-stage ejector-diffuser system. The detailed flow phenomenon of the ejector-diffuser system has been critically predicted by means of the numerical approach using compressible Reynolds averaged Navier-Stokes (RANS) equations. The axi-symmetric supersonic ejector-diffuser flow has been solved by a fully implicit finite volume scheme with a two-equation k-omega turbulence model. The numerical results are validated with existing experimental data. Detailed flow physics and their contributions on ejector performance are detected to compare both single-stage and two-stage ejectors. The performance improvement on the ejector-diffuser system is discussed in terms of the mass flux ratio and the coefficient of power.

Keywords

References

  1. Y. M. Chen and C. Y. Sun, "Experimental study of the performance characteristics of a steam-ejector refrigeration system," Experimental Thermal and Fluid Science, vol. 15, no. 4, pp. 384-394, 1997. https://doi.org/10.1016/S0894-1777(97)00006-X
  2. Z. Aidoun and Ouzzane M, "The effect of operating conditions on the performance of a supersonic ejector for refrigeration," International Journal of Refrigeration, vol. 27, no. 8, pp. 974-984, 2004. https://doi.org/10.1016/j.ijrefrig.2004.05.006
  3. V. Lijo, H. D. Kim, S. Matsuo, and T. Setoguchi, "A study of the supersonic ejector-diffuser system with an inlet orifice," Aerospace Science and Technology, vol. 23, no. 1, pp. 321-329, 2011. https://doi.org/10.1016/j.ast.2011.08.009
  4. X. Yang, X. Long, X. Yao, "Numerical investigation on the mixing process in a stream ejector with different nozzle structures," International Journal of Thermal Sciences, vol. 56, pp. 95-106, 2012.. https://doi.org/10.1016/j.ijthermalsci.2012.01.021
  5. D. V. Manoha, Desalination of Seawater using a High-Efficiency Jet Ejector, M.S. Thesis, Department of Chemical Engineering, Texas A&M University, 2005.
  6. W. Somsak, CFD Optimization Study of High-Efficiency Jet Ejector, Doctoral Dissertation, Department of Chemical Engineering, Texas A&M University, 2008.
  7. M. N. Biswas and A. K. Mitra, "Momentum transfer in horizontal multi‐jet liquid‐gas ejector," The Canadian Journal of Chemical Engineering, vol. 59, no. 5, pp. 634-637, 1981. https://doi.org/10.1002/cjce.5450590513
  8. K. Pianthonga, W. Seehanama, M. Behniab, T. Sriveerakula, and S. Aphornratana, "Investigation and improvement of ejector refrigeration system using computational fluid dynamics technique," Energy Conversion and Management, vol. 48, no. 9, pp. 2556-2564, 2007. https://doi.org/10.1016/j.enconman.2007.03.021
  9. F. S. Kong, H. D. Kim, Y. Z. Jin, T. Setoguchi, "Computational analysis of mixing guide vane effects on performance of the supersonic ejector-diffuser system," Open Journal of Fluid Dynamics, vol. 2, no. 3, pp. 45-55, 2012. https://doi.org/10.4236/ojfd.2012.23005
  10. G. Grazzini and R. Andrea, "Numerical optimisation of a two-stage ejector refrigeration plant," International Journal of Refrigeration, vol. 25, no. 5, pp. 621-633, 2002. https://doi.org/10.1016/S0140-7007(01)00063-9
  11. G. Singhal, A. L. Dawar, and P. M. V. Subbarao, "Application of profiled ejector in chemical lasers," Applied Thermal Engineering, vol. 28, no. 11, pp. 1333-1341, 2008. https://doi.org/10.1016/j.applthermaleng.2007.10.009
  12. X. Gamisans, S. Montserrrat, and F. J. .Lafuente, "Gas pollutants removal in a single-and two-stage ejector-venturi scrubber," Journal of Hazardous Materials, vol. 90, no. 3, pp. 251-266, 2002. https://doi.org/10.1016/S0304-3894(01)00352-1
  13. G. Singhala, R. Rajesha, Mainuddina, R. K. Tyagia, A. L. Dawara, P. M. V. Subbaraob, and M. Endo, "Two-stage ejector based pressure recovery system for small scale SCOIL," Experimental Thermal and Fluid Science, vol. 30, no. 5, pp. 415-426, 2006. https://doi.org/10.1016/j.expthermflusci.2005.09.002