Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Effect of Ignition Delay Time on Autoignited Laminar Lifted Flames

자발화된 층류 부상화염에 대한 점화지연시간의 영향

  • 최병철 ((사)한국선급 환경플랜트팀)
  • Received : 2011.06.21
  • Accepted : 2011.08.09
  • Published : 2011.10.01
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Abstract

Autoignition characteristic is an important parameter for designing diesel or PCCI engines. In particular, diesel spray flames are lifted from the nozzle and the initial flame is formed by an autoignition phenomenon. The lifted nature of diesel spray flames influences soot formation, since air will be entrained into the spray core by the entrainment of air between the nozzle region and the lifted flame base. The objective of the present study was to identify the effect of heat loss on the ignition delay time by adopting a coflow jet as a model problem. Methane ($CH_4$), ethylene ($C_2H_4$), ethane ($C_2H_6$), propene ($C_3H_6$), propane ($C_3H_8$), and normal butane (n-$C_4H_{10}$) fuels were injected into high temperature air, and the liftoff height was measured experimentally. As the result, a correlation was determined between the liftoff height of the autoignited lifted flame and the ignition delay time considering the heat loss to the atmosphere.

자발화 특성은 디젤 및 PCCI 엔진의 설계에서 중요한 인자이다. 특히, 디젤분무화염은 자발화현상에 의해서 형성되어 노즐에서 부상된다. 노즐과 부상화염 사이의 영역에서 분무된 디젤의 중앙으로 주위 공기의 유입이 발생하기 때문에, 그 부상된 화염은 매연 생성에 영향을 준다. 본 연구에서 간단한 모델로써 동축류 제트를 적용하였고, 점화지연시간에 대한 자발화 과정에서 발생하는 열손실의 영향을 확인하였다. 메탄($CH_4$), 에틸렌($C_2H_4$), 에탄($C_2H_6$), 프로핀($C_3H_6$), 프로판($C_3H_8$), 및 노말 부탄(n-$C_4H_{10}$)의 연료들을 고온의 공기로 분사하였으며 자발화된 부상화염의 높이를 측정하였다. 그 결과로 자발화된 부상화염의 높이와 열손실을 고려한 점화지연시간과의 상관관계를 결정하였다.

Keywords

References

  1. Flynn, P.F., Durrett, R.P., Hunter, G.L., zur Loye, A.O., Akinyemi, O.C., Dec, J.E. and Westbrook, C.K., 1999, "Diesel Combustion: An Integrated View Combining Laser Diagnostics, Chemical Kinetics, And Empirical Validation," SAE 1999-01-0509
  2. Siebers, D. and Higgins, B., 2001, "Flame Lift-Off on Direct-Injection Diesel Sprays Under Quiescent Conditions," SAE 2001-01-0530
  3. Domingo, P. and Vervisch, L., 1996, "Triple Flames and Partially Premixed Combustion in Autoignition of Non-Premixed Turbulent Mixtures," Proc. Combust. Inst., Vol. 26, pp. 233-24 https://doi.org/10.1016/S0082-0784(96)80221-9
  4. Spadaccini, L.J. and Colket, M.B., 1994, "Ignition Delay Characteristics of Methane Fuels," Prog. Energy Combust., Vol. 20, pp. 431-460. https://doi.org/10.1016/0360-1285(94)90011-6
  5. Markides, C.N. and Mastorakos, E., 2005, "An Experimental Study of Hydrogen Autoignition in a Turbulent Co-Flow of Heated Air," Proc. Combust. Inst., Vol. 30, pp. 883-891. https://doi.org/10.1016/j.proci.2004.08.024
  6. Gordon, R.L., Masri, A.R., Pope, S.B. and Goldin, G.M., 2007, "Transport Budgets in Turbulent Lifted Flames of Methane Autoigniting in a Vitiated Co- Flow," Combust. Flame, Vol. 151, pp. 495-511. https://doi.org/10.1016/j.combustflame.2007.07.001
  7. Choi, B.C., Kim, K.N. and Chung, S.H., 2009, "Autoignited Laminar Lifted Flames of Propane in Coflow Jets with Tribrachial Edge and Mild Combustion," Combust. Flame, Vol. 156, pp. 396-404. https://doi.org/10.1016/j.combustflame.2008.10.020
  8. Choi, B.C. and Chung, S.H., 2010, "Autoignited Laminar Lifted Flames of Methane, Ethylene, Ethane, and n-Butane Jets in Coflow Air with Elevated Temperature," Combust. Flame, Vol. 157, 2348-2356. https://doi.org/10.1016/j.combustflame.2010.06.011
  9. Semenov, N.N., 1935, Chemical Kinetics and Chain Reactions, Oxford at the Clarendon Press, pp.79-87.
  10. Wheatley, M., http://www.leeds.ac.uk/fuel/tutorial, Thermal Ignition Tutorial.
  11. Frank-Kamenetskii, D.A., 1969, Diffusion and Heat Transfer in Chemical Kinetics (2nd ed.), New York-London: Plenum Press, pp. 374-421.
  12. Boddington, T., Feng, C.G. and Gray, P., F.R.S., 1983, Proc. R. Soc. Lod. A, 385, pp. 289-311. https://doi.org/10.1098/rspa.1983.0016
  13. Zeldovich, Y.B., 1985, The Mathematical Theory of Combustion and Explosions, Consultants Bureau, pp. 1-185.
  14. Chung, S.H. and Lee, B.J., 1991, "On the Characteristics of Laminar Lifted Flames in a Nonpremixed Jet," Combust. Flame, Vol. 86, pp. 62-72 https://doi.org/10.1016/0010-2180(91)90056-H
  15. Lee, B.J. and Chung, S.H., 1997, "Stabilization of Lifted Tribrachial Flames in a Laminar Nonpremixed Jet," Combust. Flame, Vol. 109, pp. 163-172 https://doi.org/10.1016/S0010-2180(96)00145-9
  16. Kim, K.N., Won, S.H. and Chung, S.H., 2006, "Characteristics of Turbulent Lifted Flames in Coflow Jets with Initial Temperature Variation," Proc. Combust. Inst., Vol. 31, pp. 1591-1598.
  17. Kim, K.N., Won, S.H. and Chung, S.H., 2007, "Characteristics of Laminar Lifted Flames in Coflow Jets with Initial Temperature Variation," Proc. Combust. Inst., Vol. 31, pp. 947-954. https://doi.org/10.1016/j.proci.2006.08.012
  18. Choi, B.C. and Chung, S.H., 2008, "Characteristics of Methane Turbulent Lifted Flames in Coflow Jets with Initial Temperature Variation," Trans. KSME (B), Vol. 32 No. 12, pp. 970-976. https://doi.org/10.3795/KSME-B.2008.32.12.970

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