Numerical Study on Optimization of the SCR Process Design in Horizontal HRSG for NOx Reduction

수평형 폐열회수보일러 배기탈질 SCR시스템의 최적설계를 위한 수치해석적 연구

Kim, Kyeongsook;Lee, Kyeongok

  • Received : 2013.10.10
  • Accepted : 2013.11.14
  • Published : 2013.11.29


The SCR (selective catalytic reduction) system is highly-effective technique for NOx reduction from exhaust gases. In this study, the effects of the direction and size of nozzle and the ammonia injection concentration on the performance of SCR system are analyzed by using the computational fluid dynamics method. When the nozzle is arranged in zigzaged direction which is normal to exhausted gas flow, it is shown that the uniformity of gas flow and the NH3/NO molar ratio is improved remarkably. With the change of the ammonia injection concentration from 0.2 vol%(wet) to 1.0 vol%(wet), the uniformity of gas flow shows a good results. As the size of nozzle diameter changes from 6 mm to 12 mm, the uniformity of gas flow is maintained well. It is shown that the uniformity of the $NH_3/NO$ molar ratio becomes better with decreasing the ammonia injection concentration and the size of nozzle diameter.




  1. Launder, B. E., Spalding, D. B., 1972, Lectures in Mathematical Models of Turbulence. Academic Press, London, England.
  2. Cho, J. H., Cho, C. Y., Jang S., P., Shin, D. H., Chung, T. Y., 2009, Numerial study for flow optimazation in selective catalytic reduction, KOSCO Symposium, 151-155.
  3. KMOE(The Korean Ministry Of Environment), 2013, Special Act on Metropolitan Air Quality Improvement.
  4. Lee, I. Y., Kim, D. W., Lee, J. B., Yoo, K. O., 2001, Reduced scale model experiments and numerical simulation for flow uniformity in de-NOx SCR reactor, J. KOSAE, 17(4) 347-354.
  5. Moon, S. H., 1998, A study on the SCR process design for denitrification of thermal power plant flue gas, J. of KOSEE, 20(8) 1171-1184.
  6. Oh, K. S., 1995, Development of design technology for combined and cogeneration power plant, J. KSME, 6, 542-553.
  7. Ottaviani, E., Jean, E., Albert, H., Amon, B., Burkardt, A., Buder, M., 2009, Dual Line Exhaust Design Optimisation to Maximize SCR Catalyst Efficiency thru Improved Ammonia Distribution, SAE Int. 2009-01-0914.
  8. Park, Y. B. Jang, C. M., 2009, Optimization for flow uniformity on the selective catalytic reduction (SCR) system of a steam supply boiler, Proceedings of Soc. ACRE Korea Conference, 415-429.
  9. Park, M. J., Chang, H. S., Ha, J. S., 2010, Numerical study on the baffle structure for determining the flow characteristic in small scale SCR system, J. Korean Soc. Environ. Eng., 32(9), 862-869.
  10. Seo, M. H., Chang, H. S., 2012, Computational study on design of the AIG for the enhancement of ammonia injection in SCR system, Clean Technology, 18(4), 410-418.