Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
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Analysis of an internal flow with multi-perforated tube geometry in an integrated Urea-SCR muffler

다공튜브 형상변화에 따른 촉매 삽입형 Urea-SCR 머플러 내부유동 해석

  • Moon, Namsoo (Jeonbuk Institute of Automotive Technology) ;
  • Lee, Sangkyoo (Ssangyong Motor Company) ;
  • Lee, Jeekeun (Division of Mechanical System Engineering, College of Engineering, Chonbuk National University)
  • Received : 2013.04.05
  • Accepted : 2013.06.05
  • Published : 2013.07.31
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Abstract

This study reports a numerical analysis of the internal flow characteristics of the integrated urea-SCR muffler system with the various geometries of the multi-perforated tube which is set up between the muffler inlet and in front of SCR catalysts. The multi-perforated tube is generally used to disperse uniformly the urea-water solution spray and to make better use of the SCR catalyst, resulting in the increased $NO_x$ reduction and decreased ammonia slip. The effects of the multi-perforated tube orifice area ratios on the velocity distributions in front of the SCR catalyst, which is ultimately quantified as the uniformity index, were investigated for the optimal muffler system design. The steady flow model was applied by using a general-purpose commercial software package. The air at the room temperature was used as a working fluid, instead of the exhaust gas and urea-water solution spray mixture. From the analysis results, it was clarified that the multi-perforated tube geometry sensitively affected to the formation of the bulk swirling motion inside the plenum chamber set in front of the SCR catalyst and to the uniformity index of the velocity distribution produced at the inlet of the catalyst.

SCR 머플러 입구와 촉매사이에 설치되는 다공튜브 형상변화에 따른 촉매 삽입형 urea-SCR 머플러 내부유동특성이 해석적으로 조사되었다. 다공튜브는 요소수 분무와 배기가스 혼합물의 공간분포 향상을 통한 $NO_x$ 저감율 증대 및 암모니아 슬립을 방지하기 위해 사용되는 장치이다. 다공튜브 오리피스 면적비 변화가 챔버 내부 유동 및 촉매 전후단의 속도분포에 끼치는 영향이 조사되었으며, 속도분포에 대한 균일도 지수가 최적설계 관점에서 평가되었다. 해석은 상용 유동해석 프로그램을 이용하여 정상상태에서 수행되었으며 요소수 분무와 배기가스 혼합물 대신 상온의 공기가 작동유체로 사용되었다. 해석결과로부터 다공튜브 형상은 머플러 입구와 촉매 전단 사이에 형성된 챔버 내 벌크 선회유동과 촉매 전후단 속도분포의 균일도지수에 큰 영향을 끼침을 알 수 있었다.

Keywords

References

  1. X. Zhang and M. Romzek, "3-D Numerical study of flow mixing in front of SCR for different injection systems," Society of Automotive Engineers Technical Paper 2007-01-1578, 2007.
  2. J. Girard, R. Snow, G. Cavataio, and Christine Lambert, "The influence of ammonia to NOX ratio on SCR performance," Society of Automotive Engineers Technical Paper 2007-01-1581, 2007.
  3. K. Narayanaswamy and Y. He, "Modeling of Copper-zeolite and Iron-zeolite selective catalytic reduction (SCR) catalysts at steady state and transient conditions," Society of Automotive Engineers Technical Paper 2008-01-0615, 2008.
  4. J. Thompson, J. O. De Beeck, E. Joubert, and T. Wilhelm, "Case studies of urea SCR integration on passenger cars monitoring of urea inside the tank during hot and cold environment test missions," Society of Automotive Engineers Technical Paper 2008-01-1181, 2008.
  5. Z. Huang, Z. Zhu, Z. Liu, and Q. Liu, "Formation and reaction of ammonium sulfate salts on V2O5/AC catalyst during selective catalytic reduction of nitric oxide by ammonia at low temperatures," Journal of Catalysis, vol. 214, pp. 213-219, 2003. https://doi.org/10.1016/S0021-9517(02)00157-4
  6. J. S. Lee, D. S. Baik, and S. W. Lee, "Evaluation of SCR system in heavy-duty diesel engine," Society of Automotive Engineers Technical Paper 2008-01-1320, 2008.
  7. S. Rajadurai, "Improved NOx reduction using wiremesh thermolysis mixer in urea SCR system," Society of Automotive Engineers Technical Paper 2008-01-2636, 2008.
  8. T. K. Kim, Y. M. Sung, S. H. Han, S. J. Ha, G. M. Choi, and D. J. Kim, "Effect of mixer structure on turbulence and mixing with urea-water solution in marine SCR system," Journal of the Korean Society of Marine Engineering, vol. 36, no. 6, pp. 814-822, 2012. https://doi.org/10.5916/jkosme.2012.36.6.814
  9. X. Zhang, M. Romzek, and C. Morgan, "3-D numerical study of mixing characteristics of NH3 in front of SCR," Society of Automotive Engineers Technical Paper 2006-01-3444, 2006.
  10. H. Weltens, H. Bressler, F. Terres, H. Neumaier, and D. Rammoser, "Optimization of catalytic converter gas flow distribution by CFD prediction," Society of Automotive Engineers Technical paper 930780, 1993.
  11. Å. Johansson, U. Wallin, M. Karlsson, A. Isaksson, and P. Bush, "Investigation on uniformity indices used for diesel exhaust aftertreatment systems," Society of Automotive Engineers Technical Paper 2008-01-0613, 2008.
  12. J. J. Oesterle, S. Calvo, B. Damson, G. Feyl, F. Neumann, and J. Rudelt, "Urea systems in focus - new challenges and solutions in the development of car and commercial vehicle exhaust systems," Society of Automotive Engineers Technical Paper 2008-01-1186, 2008.
  13. J. J. Oesterle, S. Calvo, B. Damson, F. Neumann, and J. Rudelt, "SCR technology with focus to stringent emissions legislation," Society of Automotive Engineers Technical Paper 2008-01-2640, 2008.
  14. M. Karlsson, U. Wallin, S. Fredholm, J. Jansson, G. Wahlström, C. M. Schär, C. H. Onder, and L. Guzzella, "A combined 3D/lumped modeling approach to ammonia SCR after-treatment systems: application to mixer designs," Society of Automotive Engineers Technical Paper 2006-01-0469, 2006.
  15. H. S. Lee, J. H. Ha, L. O. Pahn, and S. H. Lee, "An internal flow analysis for automobile mufflers," Proceedings of The Korean Society of Automotive Engineers, pp. 1804-1088, 2005.
  16. K. T. Han, "A study on the perforating process of the muffer tube using FEM," Journal of the Korean Society of Marine Engineering, vol. 29, no. 3, pp. 275-280, 2005.
  17. S. J. Jeong, W. Kang, J. J. Lee, and T. H. Kim, "Exhaust system design for the integrated automotive muffler," Transactions of The Korean Society of Automotive Engineers, vol. 17, no. 4, pp. 24-31, 2009.
  18. S. K. Lee, N. S. Moon, and J. K. Lee, "A study on exit flow characteristics according to the orifice configuration of multi-perforated tubes," Journal of Mechanical Science and Technology, vol. 26, no. 9, pp. 2751-2758, 2012. https://doi.org/10.1007/s12206-012-0721-z
  19. C. N, Wang, "A numerical scheme for the analysis of perforated intruding tube muffler components," Applied Acoustics, vol. 44, pp. 215-286, 1995. https://doi.org/10.1016/0003-682X(94)00020-V
  20. Fluent User Guide. 6.2, The RNG k-e Model, pp. 11-17.

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