비예혼합 대향류 화염에서 $CO_2$ 첨가가 화염 구조에 미치는 영향 연구

An Effects of $CO_2$ Addition on Flame Structure in a Non-premixed Counterflow Flame

  • 이기만 (순천대학교 기계우주항공공학부)
  • Lee, Kee-Man (School of Mechanical and Aerospace Engineering, Sunchon National University)
  • 발행 : 2007.05.01

초록

A numerical study was conducted to have the effect of $CO_2$ addition to fuel on the chemical reaction mechanism with the change of the initial concentration of $CO_2$ and the axial velocity gradient. From this study, it was found that there were two serious effects of $CO_2$ addition on a non-premixed flame ; a diluent effect by the reactive species reduction and chemical effect of the breakdown of $CO_2$ by the third-body collision and thermal dissociation. Especially, the chemical effect was serious at the lower velocity gradient of the axial flow. It was certain that the mole fraction profile of $CO_2$ was deflected and CO was increased with the initial concentration of $CO_2$. It was also ascertained that the breakdown of $CO_2$ would cause the increasing of CO mole fraction at the reaction region. It was also found that the addition of $CO_2$ did not alter the basic skeleton of $H_2-O_2$ reaction mechanism, but contributed to the formation and destruction of hydrocarbon products such as HCO. The conversion of CO was also suppressed and $CO_2$ played a role of a dilution in the reaction zone at the higher axial velocity gradient.

키워드

참고문헌

  1. N. Peters, 'Laminar Diffusion Flamelet Models in Non-premixed Turbulent Combustion,' Progress in Energy and Combustion Science, Vol.10, p.319, 1984 https://doi.org/10.1016/0360-1285(84)90114-X
  2. R. J. Kee, J. A. Miller, G. H. Evans and G. Dixon-Lewis, 'A Computational Model of the Structure and Extinction of Strained, Opposed Flow, Premixed Methane-air Flame,' Proceedings of the 22nd Int. Symposium on Combustion, The Combustion Institute, p. 1479, 1988
  3. A. E. Lutz, R. J. Kee, J. F. Grcar and F. M. Rupley, 'OPPDIF : A Fortran Program for Computing Opposed-flow Diffusion Flames,' SAND96-8243, 1996
  4. M. C. Drake and R. J. Blint, 'Structure of Laminar Opposed-flow Diffusion Flames with CO/H2/N2 Fuel,' Combustion Science and Technology, Vol.61, p.187, 1988 https://doi.org/10.1080/00102208808915763
  5. R. J. Kee, F. M. Rupley and J. A. Miller, 'Chemkin : A General-purpose, Problemindependent, Transportable, Fortran Chemical Kinetic Code Package,' SAND80-8003, 1980
  6. C. K. Westbrook and F. L. Dryer, 'Chemical Kinetic Modeling of Hydrocarbon Combustion,' Progress in Energy and Combustion Science, Vol.10, p.1, 1984 https://doi.org/10.1016/0360-1285(84)90118-7
  7. D. X. Du, R. J. Axelbaum and C. K. Law, 'The Influence of Carbon Dioxide and Oxygen as Additives on Soot Formation in Diffusion Flame,' Proceedings of the 23rd Int. Symposium on Combustion, The Combustion Institute, p.1501, 1990
  8. N. Darabiha, 'Transient Behavior of Laminar Counterflow Hydrogen-air Diffusion Flames with Complex Chemistry,' Combustion Science and Technology, Vol.86, p.163, 1992 https://doi.org/10.1080/00102209208947193