DOI QR코드

DOI QR Code

일반 공기 및 순산소 연소 조건에서 Fuel-NOx 생성 특성의 비교

Comparison of Fuel-NOx Formation Characteristics in Conventional Air and Oxyfuel Combustion Conditions

  • 우민호 ((주)경원이앤씨) ;
  • 박권하 (한국해양대학교 기계에너지시스템공학부) ;
  • 최병철 ((사)한국선급 환경플랜트팀)
  • Woo, Mino (Kyungwon Engineering and Communication) ;
  • Park, Kweon Ha (Division of Mechanical and Energy Systems Engineering, Korea Maritime Univ.) ;
  • Choi, Byung Chul (Environment & Plant Team, Korean Register of Shipping)
  • 투고 : 2012.10.17
  • 심사 : 2013.02.12
  • 발행 : 2013.05.01

초록

10 %의 암모니아가 첨가된 메탄 연료의 비예혼합 확산화염에서, 산소/이산화탄소 및 산소/질소의 산화제 내에 산소 비율의 변화에 따른 질소산화물($NO_x$)의 생성 특성을 실험 및 수치해석적으로 조사하였다. 동축류 제트 화염의 실험에서, 산소/이산화탄소의 산화제인 경우, 측정된 $NO_x$은 산소 비율의 증가에 따라 약간 증가하는 경향을 보였다. 반면에, 산소/질소의 산화제인 경우, $NO_x$은 0.7의 산소 비율에서 최대로 측정되었으며, 산소 비율에 따라 비단조적인 경향을 보였다. 결과적으로, 암모니아가 첨가된 메탄 화염에서 배출되는 $NO_x$는 일반 공기의 조건보다 순산소 연소 조건의 경우가 더 크게 측정되었다. 한편, 다양한 산화제의 조건에 대하여 $NO_x$ 생성 특성을 분석하기 위해서, 동일한 화학반응 메커니즘을 적용하여 1 차원 및 2 차원의 수치해석을 수행하였다. 그 결과, 산소/질소의 산화제에서 2 차원의 수치해석 결과가 실험적으로 측정된 $NO_x$의 배출 특성을 비교적 잘 예측하였다.

Nitric oxide ($NO_x$) formation characteristics in non-premixed diffusion flames of methane fuels have been investigated experimentally and numerically by adding 10% ammonia to the fuel stream, according to the variation of the oxygen ratio in the oxidizer with oxygen/carbon dioxide and oxygen/nitrogen mixtures. In an experiment of coflow jet flames, in the case of an oxidizer with oxygen/carbon dioxide, the $NO_x$ emission increased slightly as the oxygen ratio increased. On the other hand, in case of an oxygen/nitrogen oxidizer, the $NO_x$ emission was the maximum at an oxygen ratio of 0.7, and it exhibited non-monotonic behavior according to the oxygen ratio. Consequently, the $NO_x$ emission in the condition of oxyfuel combustion was overestimated as compared to that in the condition of conventional air combustion. To elucidate the characteristics of $NO_x$ formation for various oxidizer compositions, 1D and 2D numerical simulations have been conducted by adopting one kinetic mechanism. The result of 2D simulation for an oxidizer with oxygen/nitrogen well predicted the trend of experimentally measured $NO_x$ emissions.

키워드

참고문헌

  1. Mackie, J.C., Colket III, M.B. and Nelson, P.F., 1990, "Shock Tube Pyrolysis of Pyridine," The Journal of Physical Chemistry, Vol. 94, No. 10, pp. 4099-4106. https://doi.org/10.1021/j100373a040
  2. Ahn, K.Y., Kim, H.S., Cho, E.S., Ahn, J.H. and Kim, Y.M., 1999, "An Experimental Study on Combustion Process and NOx emission Characteristics of the Air- Staged Burner," KSME International Journal, Vol. 13, No. 6, pp. 477-486. https://doi.org/10.1007/BF02947717
  3. Puccio, M.A. and Miller, J.H., 2006, "The Chemical Structure of Pyridine-Doped Methane/Air, Non- Premixed Flames: Tracking the Fate of Fuel Nitrogen," 5th US Combustion Meeting, The University of California at San Diego, 25-28 March.
  4. Fenimore, C.P., 1972, "Formation of Nitric Oxide from Fuel Nitrogen in Ethylene Flames," Combustion and Flame, Vol. 19, No. 2, pp. 289-296. https://doi.org/10.1016/S0010-2180(72)80219-0
  5. Takagi, T., Tatsumi, T. and Ogasawara, M., 1979, "Nitric Oxide Formation from Fuel Nitrogen in Staged Combustion: Roles of HCN and NHi," Combustion and Flame, Vol. 35, pp. 17-25. https://doi.org/10.1016/0010-2180(79)90003-8
  6. Martins, C.A., Carvalho, Jr J.A., Veras, C.A.G., Ferreira, M.A. and Lacava, P.T., 2006, "Experimental Measurements of the $NO_{x}$ and CO Concentrations Operating in Oscillatory and Non-Oscillatory Burning Conditions," Fuel, Vol. 85, No. 1, pp. 84-93. https://doi.org/10.1016/j.fuel.2005.05.020
  7. ESI-CFD, 2012, "CFD-ACE+ V2011.0 User Manual," ESI-Group, www.esi-group.com
  8. Smith, G.P., Golden, D.M., Frenklach, M., Moriarty, N.W., Eiteneer, B., Goldenberg, M., Bowman, C.T., Hanson, R.K., Song, S., Gardiner, W.C., Lissianksi, V.V. and Qin, Z., http://www.me.berkeley.edu/gri_mech/.
  9. Lutz, A.E., Kee, R.J., Grcar, J.F. and Rupley, F.M., 1997, "OPPDIF: A Fortran Program for Computing Opposed-Flow Diffusion Flames," Report No. SAND 96-8243, Sandia National Laboratories.
  10. Gardiner, W.C., Lissianski, V.V., Qin, Z., Smith, G.P., Golden, D.M., Freanklach, M., Eiteneer, B., Goldenberg, M., Moriarty, N.W., Bowman, C.T., Hanson, R.K., Song, S., Schmidt, C.C. and Serauskas, R.V., 1999, "The GRIMech TM Model for Natural Gas Combustion and NO Formation and Removal Chemistry," 5th Int. Conference on Combustion Technologies for a Clean Environment.
  11. Turns, S.R., An Introduction to Combustion: Concept and Applications, 2nd Ed., McGraw-Hill, 168-173.
  12. Glassman, I. and Yetter, A.R., 2008, Combustion, 4th Ed., Academic Press, pp. 417-441.
  13. Wall, T., Liu, Y., Spero, C., Elliott, L., Khare, S., Rathnam, R., Zeenathal, F., Moghtaderi, B., Buhre, B., Sheng, C., Gupta, R., Yamada, T., Makino, K. and Yu, J., 2009, "An Overview on Oxyfuel Coal Combustion- State of the Art Research and Technology Development," Chemical Engineering Research and Design, Vol. 87, pp. 1003-1016. https://doi.org/10.1016/j.cherd.2009.02.005
  14. Baukal, C.E. Jr., 1998, Oxygen-Enhanced Combustion, CRC Press LLC, Chapter 2.
  15. Driscoll, J.F., Chen, R.H. and Yoon, Y.B., 1992, "Nitric Oxide Levels of Jet Diffusion Flames: Effects of Residence Time and Damkoler Number," Combustion and Flame, Vol. 88, pp. 37-49. https://doi.org/10.1016/0010-2180(92)90005-A