Browse > Article
http://dx.doi.org/10.5916/jkosme.2013.37.4.368

Wall flow characteristics with static mixer position and housing geometry for preventing urea-salt deposition  

Lee, Banguk (현대자동차(주))
Lee, Jeekeun (전북대학교 기계시스템공학부)
Publication Information
Journal of Advanced Marine Engineering and Technology / v.37, no.4, 2013 , pp. 368-377 More about this Journal
Abstract
The Urea-SCR system commercialized shows a remarkable performance to reduce NOx emission in heavy duty diesel engines. However, Urea-water solution injected upstream a mixer, which is set up inside a exhaust pipe to promote exhaust gas-atomized droplet mixing, bumps up against the wall of a exhaust pipe as the droplets flow downstream through the exhaust gas. The urea deposited on the wall of the exhaust pipe is changed into the Urea-salt, resulting in the decreased life-time of the SCR catalysts. Therefore, the development of the urea deposition avoidance technologies is being treated as an important issue of the Urea-SCR systems. An experimental study was carried out to investigate the effects of the wall flow characteristics around the mixer-housing assembly with the variation of the mixer housing surrounding and supporting the mixer, which is designed to increase the wall flow and then to reduce droplet deposition. The flow characteristics was investigated by using a hot-wire anemometry for 2-D simplified duct model, and the housing tilt angles and the position of the mixer were changed : angle of $0^{\circ}$, $1^{\circ}$, $2^{\circ}$, $3^{\circ}$, and mixer positions of 0L, 0.5L, 1L. The results showed that the wall flow onto the exhaust pipe was improved with changing the tilt angle of the mixer housing, and the wall flow improved more when the position of the mixer was on 1L.
Keywords
Mixer-housing assembly; Urea-water solution; Wall flow; Urea-salt deposition; Selective Catalytic Reduction(SCR);
Citations & Related Records
Times Cited By KSCI : 8  (Citation Analysis)
연도 인용수 순위
1 M. Koebel, M. Elsener, and M. Kleemann, "Urea-SCR: A promising technique to reduce NOx emissions from automotive diesel engines," Catalysis Today, vol. 59, pp. 335-345, 2000.   DOI   ScienceOn
2 S. Grout, J. Blaisot, K. Pajot, and G. Osbat, "Experimental investigation on the injection of An urea-water solution in hot air stream for the SCR application: evaporation and spray/wall interaction," Fuel, 2012. Available: http://dx.doi.org/10.1016/j.fuel.2012.09.022
3 H. Liu, T. Guo, Y. Yang, and G. Lu, "Optimization and numerical simulation of the flow characteristics in SCR system," Energy Procedia, vol. 17, pp. 801-812, 2012.   DOI   ScienceOn
4 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.   과학기술학회마을   DOI   ScienceOn
5 M. W. Bae, Syaiful, and Y. Mochimaru, "A study on numerical simulation of gaseous flow in SCR catalytic filter of diesel exhaust gas after treatment device," Journal of the Korean Society of Marine Engineering, vol. 34, no. 3, pp. 360-368, 2010.   DOI   ScienceOn
6 J. W. Seo, K. I. Lee, J. T. Oh, Y. H. Choi, J. H. Lee, and J. I. Park, "The study on the effects of mixer configurations on fluid mixing characteristics in SCR systems," Transactions of Korean Society of Automotive Engineers, vol. 16, no. 6, pp. 192-199, 2008.   과학기술학회마을
7 S. H. Ryu, J. Y. Kim, B. S. Min, and J. S. Ha, "A research on the characteristics of spray-induced mixing and thermal decomposition of urea solution in SCR system," Journal of the Korean Society of Marine Engineers, vol. 28, no. 5, pp. 818-826, 2004.   과학기술학회마을
8 J. M. Oh, W. Cha, K. Kim, J. Lee, and K. Lee, "A study on the characteristic and droplet uniformity of spray injection to exhaust gas flow from urea solution injector," Transactions of Korean Society of Automotive Engineers, vol. 19, no. 3, pp. 83-89, 2011.   과학기술학회마을
9 Y. S. Cho, S. W. Lee, I. K. Jang, Y. B. Yoon, C. S. Song, Y. J. Park, and H. O. Kim, "An experimental study on optimization of NH3 injection with Various Exhaust Gas Conditions on Selective Catalytic Reduction(SCR) System," Transactions of Korean Society of Automotive Engineers, vol. 17, no. 6, pp. 74-80, 2009.
10 S. J. Jeong, S. J. Lee, W. S. Kim, and C. B. Lee, "Numerical study on the injector shape and location of urea SCR system of heavy-duty diesel engine for preventing $NH_3$ slip," Transactions of Korean Society of Automotive Engineers, vol. 14, no. 1, pp. 68-78, 2006.   과학기술학회마을
11 H. P. Heering, C. H. Onder, M. Elsener, and C. M. Schaer, "Control of a urea SCR catalytic converter system for a mobile heavy duty diesel engine," Society of Automotive Engineers 2003-01-0776, 2003.
12 J. G. Nam and J. S. Choi, "Dynamic characteristics of a urea SCR system for NOx reduction in diesel engine," Journal of the Korean Society of Marine Engineering, vol. 31, no. 3, pp. 235-242, 2007.   과학기술학회마을   DOI   ScienceOn
13 J. S. Choi, K. H. Cho, J. H. Lee, J. W. Lee, J. G. Kim, H. S. Yang, J. H. Ko, K. Y. park, and S. H. Jang, "Investigation of NOx reduction ratio on SCR system for a marine diesel engine," Journal of the Korean Society of Marine Engineering, vol. 27, no. 6, pp. 832-838, 2003.   과학기술학회마을
14 T. V. Johnson, "Diesel Emission Control in Review," Society of Automotive Engineers 2007-01-0233, 2007.
15 H. S. Kim, Y. G. Jeong, M. H. Song, S. W. Lee, H. D. Park, and J. W. Hwang, "Influential factors for NOx reduction performance of Urea-SCR system for an in-use medium duty diesel engine," Transactions of Korean Society of Automotive Engineers, vol. 17, no. 1, pp. 154-161, 2009.
16 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.   DOI   ScienceOn