Fire Science and Engineering (한국화재소방학회논문지)

Korean Institute of Fire Science and Engineering (한국화재소방학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of CO Addition on Soot Formation in the Well Stirred Reactor

WSR에서 매연 생성에 관한 CO 첨가 효과

  • Jeong, Tae-Hee (Department of Safety Engineering, Pukyong National University) ;
  • Lee, Eui-Ju (Department of Safety Engineering, Pukyong National University)
  • 정태희 (부경대학교 안전공학과) ;
  • 이의주 (부경대학교 안전공학과)
  • Received : 2012.07.23
  • Accepted : 2012.10.12
  • Published : 2012.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

Numerical investigation was performed to study on the soot formation characteristics in the WSR according to the CO addition. Ethylene and pure air were used as a fuel and an oxidizer, respectively, and three different equivalence ratios (2.0, 2.5, 3.0) were used in the calculation. The resulted CO mole fraction of 10 % CO addition showed the maximum value in spite of the least CO supply. This means that the conversion of CO to soot and other carbon compounds is weakened under incipient soot formation. The soot volume fraction was decreased with increasing the CO addition because the important species for soot formation such as pyrene and acetylene, were decreased with the addition of CO. When the equivalence ratio was 2.5, the soot volume fraction shows the highest value, which results from the contribution of fuel rich condition and reacting temperature. Furthermore, surface growth rate and species concentrations justified the HACA mechanism for soot formation.

본 연구에서는 WSR에서 혼합기의 CO첨가 효과에 따른 매연의 생성특성을 규명하기 위하여 수치해석 연구를 수행하였다. 연료는 에틸렌을 사용하였으며, 산화제는 순수 공기를 이용하였다. 서로 다른 당량비 조건(${\phi}$=2.0, 2.5, 3.0)에서 CO의 농도를 변화시켜가며 매연 생성 특성을 조사하였다. 10 %의 CO 첨가 경우에는 가장 작은 양의 CO를 유입하는데도 불구하고, 배출되는 CO의 몰분율이 다른 당량비 경우에 비해서 최대값을 나타낸다. 이는 초기 매연이 생성되는 지점에서는 매우 적은량의 CO가 매연이나 다른 탄소화합물로 변화함을 의미한다. 매연부피분율은 CO의 첨가량이 증가함에 따라 감소되는데 매연생성에서 중요 화학종인 pyrene과 아세틸렌의 생성이 CO의 첨가에 의해 저하되기 때문이다. 또한 당량비가 2.5인 경우에 가장 많은 매연이 생성됨을 확인 할 수 있는데, 이는 연료과잉조건과 연소온도의 적절한 기여로서 설명되어 질 수 있다. 또한, 표면성장율과 중요 화학종의 농도는 매연생성에 대한 HACA(hydrogen abstraction and carbon addition)기구를 정당화한다.

Keywords

References

  1. I. M. Kennedy, "Models of Soot Formation and Oxidation", Prog. Energy Combust. Sci., Vol. 23, pp. 95-132 (1997). https://doi.org/10.1016/S0360-1285(97)00007-5
  2. H. Richter and J. B. Howard, "Formation of Polycyclic Aromatic Hydrocarbons and Their Growth to Soot - A Review of Chemical Reaction Pathways", Prog. Energy Combust. Sci., Vol. 26, pp. 565-608 (2000). https://doi.org/10.1016/S0360-1285(00)00009-5
  3. H. Guo, K. A. Thomson and G. J. Smallwood, "On the Effect of Carbon Monoxide Addition on Soot Formation in Laminar Ethylene/air Coflow Diffusion Flame", Combust. Flame, Vol. 156, pp. 1235-1142 (2009).
  4. D. X. Du, R. L. Axelbaum and C. K. Law, "Soot Formation in Strained Diffusion Flames with Gaseous Additives", Combust. Flame, Vol. 102, pp. 11-20 (1995). https://doi.org/10.1016/0010-2180(95)00043-6
  5. J. H. Ji and E. J. Lee, "The Effects of Carbon Dioxide as Additives on Soot Formation in Jet Diffusion Flames", Journal of Korean Institute of Fire Science & Engineering, Vol. 24, No. 6, pp. 170-175 (2010).
  6. J. H. Ji and E. J. Lee, "The Characteristics of Soot at the Post-flame Region in Jet Diffusion Flames Added Carbon Dioxide", Journal of Korean Society of Safety, Vol. 25, No. 6, pp. 9-13 (2010).
  7. L. G. Blevins, R. A. Fletcher, B. A. Benner, E. B. Steel and G. W. Mulholland, "The Existence of Young Soot in the Exhaust of Inverse Diffusion Flames", Proc. Comb. Inst., Vol. 29, pp. 2325-2333 (2002). https://doi.org/10.1016/S1540-7489(02)80283-8
  8. F. W. Lam, J. P. Longwell and J. B. Howard, "The Effect of Ethylene and Benzene Addition on the Formation of Polycyclic Aromatic Hydrocarbons and Soot in a Jet- Stirred/Plug-Flow Combustor", Proc. Comb. Inst., Vol. 23, pp. 1477-1484 (1990).
  9. J. P. Longwell and M. A. Weiss, "High Temperature Reaction Rates in Hydrocarbon Combustion", Industrial and Engineering Chemistry, Vol. 47, pp. 1634-1642 (1955). https://doi.org/10.1021/ie50548a049
  10. J. E. Nenniger, A. Kridiotis, J. Chomiak, J. P. Longwell and A. F. Sarofim, "Characterization of a Toroidal Well Stirred Reactor", Proc. Comb. Inst., Vol. 20, pp. 473-479 (1984).
  11. R. F. Reich, S. D. Stouffer, V. R. Katta, H. T. Mayfield, C. W. Frayne and J. Zelina, "Particulate Matter and Polycyclic Aromatic Hydrocarbon Determination Using a Well-Stirred Reactor", AIAA Paper 2003-0664 (2003).
  12. S. D. Stouffer, R. C. Striebich, C. W. Frayne and J. Zelina, "Combustion Particulates Mitigations in a Well- Stirred Reactor", AIAA Paper 2002-3723.
  13. J. W. Blust, D. R. Ballal and G. J. Sturgess, J. Propul. Power, Vol. 15, p. 216 (1999). https://doi.org/10.2514/2.5444
  14. J. Zelina and D. R. Ballal, "Combustor Stability and Emissions Research Using a Well-Stirred Reactor", Journal of Engineering for Gas Turbines and Power-Transactions of the ASME, Vol. 119, pp. 70-75 (1997). https://doi.org/10.1115/1.2815564
  15. N. J. Brown, K. L. Revzan and M. Frenklach, "Detailed Kinetic Modeling of Soot Formation in Ethylene/air Mixtures Reacting in a Perfectly Stirred Reactor", Proc. Comb. Inst., Vol. 27, pp. 1573-1580 (1998). https://doi.org/10.1016/S0082-0784(98)80566-3
  16. R. J. Kee, F. M. Rupley and J. A. Miller, "CHEMKIN-II, A FORTRAN Chemical Kinetics Package for the Analysis of Gas-phase Chemical Kinetics", Sandia Report SAND89-8009B (1991).
  17. M. Freklach and H. Wang, "in: H. Bockhorn (Ed.), Soot Formation in Combustion: Mechanism and Model", Springer-Verlag, Heidelberg, p. 165 (1994).
  18. A. Kazakov, H. Wang and M. Frenklach, Combust. Flame, Vol. 100, pp. 111-120 (1995). https://doi.org/10.1016/0010-2180(94)00086-8
  19. J. Appel and H. Bockhorn, "Kinetic Modeling of Soot Formation with Detailed Chemistry and Physics: Laminar Premixed Flames of C2 Hydrocarbons", Combust. Flame, Vol. 121, pp. 122-136 (2000). https://doi.org/10.1016/S0010-2180(99)00135-2
  20. M. Frenklach, D. Clary, W. Gardiner and S. Stein, "Detailed Kinetic Modeling of Soot Formation in Shocktube Pyrolysis of Acetylene", Proc. Comb. Inst., Vol. 20, pp. 887-901 (1985). https://doi.org/10.1016/S0082-0784(85)80578-6

Cited by

  1. A Hybrid Newton/Time Integration Approach Coupled to Soot Moment Methods for Modeling Soot Formation and Growth in Perfectly-Stirred Reactors vol.188, pp.8, 2016, https://doi.org/10.1080/00102202.2016.1177035