Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

Numerical Investigation of the Spray Behavior and Flow Characteristics of Urea-Water Solution Injected into Diesel Exhaust Pipe

디젤 배기관에 분사된 우레아 수용액의 분무 거동 및 유동 특성에 관한 연구

  • 안태현 (전북대학교 항공우주공학과) ;
  • 김만영 (전북대학교 항공우주공학과)
  • Received : 2013.06.15
  • Accepted : 2013.09.23
  • Published : 2014.01.01
Download PDF
⟨ Previous Next ⟩

Abstract

A urea-SCR system suffers from some issues associated with the ammonia slip phenomenon, which mainly occurs because of the shortage of evaporation and thermolysis time, and this makes it difficult to achieve an uniform distribution of injected urea. A numerical study was therefore performed by changing such various parameters as installed injector angle and application and angle of mixer to enhance evaporation and the mixing of urea water solution with exhaust gases. As a result, various parameters were found to affect the evaporation and mixing characteristics between exhaust gas and urea water solution, and their optimization is required. Finally, useful guidelines were suggested to achieve the optimum design of a urea-SCR injection system for improving the DeNOx performance and reducing ammonia slip.

Urea-SCR 시스템은 주로 열해리와 증발시간의 부족으로 인해 발생하는 암모니아 슬립 현상과 관련된 몇 가지 문제점들을 가지고 있으며, 이러한 문제점들은 분사된 요소수용액의 불균일한 분포를 초래한다. 따라서 본 연구에서는, 배기가스와 요소수용액 사이의 증발 및 혼합특성을 강화시키기 위해 인젝터 장착 각도 그리고 믹서의 장착 및 설치 각도와 같은 다양한 매개변수들을 바꾸며 전산해석 연구를 수행하였다. 그 결과, 이와 같은 매개변수들이 배기가스와 요소수용액의 증발 및 혼합특성에 상당한 영향을 미친다는 것을 알 수 있었으며, 이 매개변수들의 최적화가 요구된다. 또한, 본 논문은 Urea-SCR 분사 시스템의 DeNOx 성능을 증가시키고 암모니아 슬립을 감소시키기 위한 최적 설계 시 유용한 기준을 제안할 것이다.

Keywords

References

  1. Kim, M. Y., 2003, "Performance Prediction of SCR-DeNOx System for Diesel Engine NOx Emission," Transactions of the KSAE, Vol. 11, No. 3, pp. 71-76.
  2. Yun, B. K. and Kim, M. Y., 2013, "Modeling the Selective Catalytic Reduction of NOx by Ammonia over a Vanadia-Based Catalyst from Heavy Duty Diesel Exhaust Gases," Applied Thermal Engineering, Vol. 50, No. 1, pp. 152-158, January 2013. https://doi.org/10.1016/j.applthermaleng.2012.05.039
  3. Kim, J. Y., Ryu, S. H. and Ha, J. S., 2004, "Numerical Prediction on the Characteristics of Spray-Induced Mixing and Thermal Decomposition of Urea Solution in SCR System," Proc. 2004 Fall Technical Conference of the ASME Internal Combustion Engine Division, Long Beach, California, USA, pp. 165-170.
  4. Birkhold, F., Meingast, U., Wassermann, P. and Deutschmann, O., 2007, "Modeling and Simulation of the Injection of Urea-Water-Solution for Automotive SCR DeNOx-Systems," Applied Catalysis B: Environmental, Vol. 70, pp. 119-127. https://doi.org/10.1016/j.apcatb.2005.12.035
  5. Jeong, S. J., Lee, S. J. and Kim, W. S., 2008, "Numerical Study on the Optimum Injection of Urea-Water Solution for SCR DeNOx System of a Heavy-Duty Diesel Engine to Improve DeNOx Performance and Reduce $NH_3$ Slip," Environmental Engineering Science, Vol. 25, No. 7, pp. 1017-1035. https://doi.org/10.1089/ees.2007.0224
  6. Kang, K. N., Lee, J. K. and Kim, M. Y., 2012, "Numerical Study of the Flow Characteristics in a Diesel Exhaust System with a Vane-Type Static Mixer," Trans. Korean. Soc. Mech. Eng. B, Vol. 36, No. 4, pp. 397-404. https://doi.org/10.3795/KSME-B.2012.36.4.397
  7. Koebel, M., Elsener, M. and Kleemann, M., 2000, "Urea-SCR: A Promising Technique to Reduce NOx Emissions from Automotive Diesel Engines," Catalysis Today, Vol. 59, pp. 335-345. https://doi.org/10.1016/S0920-5861(00)00299-6
  8. Seong, H. J., 2012, "Selective Catalytic Reduction (SCR) of NO by $NH_{3}$ in a Fixed-bed Reactor," M. S. Dissertation, The Pennsylvania State University, Pennsylvania.
  9. Tsinoglou, D. and Koltsakis, G., 2007, "Modeling of the Selective Catalytic NOx Reduction in Diesel Exhaust including Ammonia Storage," Proceedings of the I Mech E Part D Journal of Automobile Engineering, Vol. 221, pp. 117-133. https://doi.org/10.1243/09544070JAUTO368
  10. AVL $FIRE^{TM}$, 2011, Lagrangian Multiphase Module, Edition 10/2011.
  11. Strom, H., Lundstrom, A. and Andersson, B., 2009, "Choice of Urea-Spray Models in CFD Simulations of Urea-SCR Systems," Chemical Engineering Journal, Vol. 150, No. 1, pp. 69-82. https://doi.org/10.1016/j.cej.2008.12.003
  12. Gosman, A. D. and Ioannides, E., 1983, "Aspects of Computer Simulation of Liquid-Fueled Combustors," AIAA Journal of energy, Vol. 7, No. 6, pp. 482-490.
  13. Kee, R. J., Rupley, F. M., Meeks, E. and Miller, J. A., 1996, "Chemkin III: A Fortran Chemical Kinetics Package for the Analysis of Gas-Phase Chemical and Plasma Kinetics," Technical Report SAND 96-8216, Sandia National Laboratories.
  14. Kuhnke, D., 2004, "Spray/Wall-Interation Modelling by Dimensionless Data Analysis," Shaker, Verlag, ISBN 3-8322-3539-6.
  15. H. Weltens, H. Bressler, F. Terres, H. Neumaier, and D. Rammoser, 1993, "Optimisation of Catalytic Converter Gas Flow Distribution by CFD Predictions," SAE Paper 930780.
  16. An, T. H., Kim M. Y., Jung, H. S., Kim, H. S. and Cho, G. B., 2013, "Investigation of the Urea Evaporation and Mixing with Various Temperatures and Injector and Injection Angles in the Catalytic Muffler," SAE World Congress, Detroit, Michigan, USA, SAE 2013-01-1078.
  17. Han, Y. D., Oh, J. M., Mun, W. K., Kim, K. B., Lee, J. H. and Lee. K. H., 2009, "An Effect of Various Mixer-Types on Spatial Distribution of LNT Reducing Agent," Proceedings of the KSME Thermal Engineering Spring Conference, pp. 246-249, Busan, 2009. 5. 20.-22.

Cited by

  1. Data Evaluation Methods for Real Driving Emissions using Portable Emissions Measurement System(PEMS) vol.39, pp.12, 2015, https://doi.org/10.3795/KSME-B.2015.39.12.965
  2. Experimental Study on Characteristics of Ammonia Conversion Rate of Urea Aqueous Solution in 250℃ Exhaust Pipe vol.39, pp.2, 2015, https://doi.org/10.3795/KSME-B.2015.39.2.177