Investigation of Autoignition of Propane and n-Butane Blends Using a Rapid Compression Machine

  • Kim, Hyunguk (School of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Yongseob Lim (School of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Kyoungdoug Min (School of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Lee, Daeyup (School of Mechanical Engineering, Inha University)
  • Published : 2002.08.01

Abstract

The effects of pressure and temperature on the autoignition of propane and n-butane blends were investigated using a rapid compression machine (RCM) , which is widely used to examine the autoignition characteristics. The RCM was designed to be capable of varying the compression ratio between 5 and 20 and minimize the vortex formation on the cylinder wall using a wedge-shaped crevice. The initial temperature and pressure of the compressed gas were varied in range of 720∼900 K and 1.6∼ 1.8 MPa, respectively, by adjusting the ratio of the specific heat of the mixture by altering the ratio of the non-reactive components (N$_2$, Ar) under a constant effective equivalence ratio (ø$\_$f/= 1.0) The gas temperature after the compression stroke could be obtained from the measured time-pressure record. The results showed a two-stage ignition delay and a Negative Temperature Coefficient (NTC) behavior which were the unique characteristic of the alkane series fuels. As the propane concentration in the blend were increased from 20% and 40% propane, the autoignition delay time increased by approximately 41 % and 55% at 750 K. Numerical reduced kinetic modeling was performed using the Shell model, which introduced some important chemical ideas, represented by the generic species. Several rate coefficients were calibrated based on the experimental results to establish an autoignition model of the propane and n-butane blends. These coefficients can be used to predict the autoignition characteristics in LPG fueled Sl engines.

Keywords

References

  1. Cox, A. and Cole, J. A., 1985, 'Chemical Aspects of the Autoignition of Hydrocarbon-Air Mixtures', Combustion and Flame, Vol. 60, pp. 109-123 https://doi.org/10.1016/0010-2180(85)90001-X
  2. Griffiths, J. F., Halford-Maw, P. A. and Rose, D. J., 1993, 'Fundamental Features of Hydrocarbon Autoignition in a Rapid Compression Machine', Combustion and Flame, Vol. 95, pp. 291-306 https://doi.org/10.1016/0010-2180(93)90133-N
  3. Ho, S. Y. and Kuo, T., 1997, 'A Hydrocarbon Autoignition Model for Knocking Combustion in SI Engines', SAE Paper, 971672
  4. Kim, I., Lee, D. and Goto, S., 1997, 'Combustion Process Modeling Using a Mechanism in a an LPG Lean Burn SI Engine', SAE Paper, 970899
  5. Lee, D. and Goto, S. et al., 2000, 'Chemical Kinetic Study of a Cetane Number Enhancing Additive for an LPG DI Diesel Engine', SAE Paper, 2000-01-0193
  6. Lee, D., 1993, 'Autoignition Measurements and Modeling in a Rapid Compression Machine, Ph. D. Thesis, MIT
  7. Minetti, R., Carlier, M., Ribaucour, M., Therssen, E. and Sochet, L. R., 1995, 'A Rapid Compression Machine Investigation of Oxidation and Auto-Ignition of n-Heptane : Measurements and Modeling', Combustion and Flame, Vol. 102, pp. 298-309 https://doi.org/10.1016/0010-2180(94)00236-L
  8. Minetti, R., Carlier, M., Ribaucour, M., Therssen E. and Sochet, L. R., 1996, 'Comparison of Oxidation and Autoignition of the Two Promary Reference Fuels by Rapid Compression,' The 26th Symposium International on Combustion, pp. 747-753
  9. Minetti, R., Ribaucour, M., Carlier, M., Fittschen, C. and Sochet, L. R., 1994, 'Experimental and Modeling Study of Oxidation and Autoignition of Butane at High Pressure,' Combustion and Flame, Vol. 96, pp. 201-211 https://doi.org/10.1016/0010-2180(94)90009-4
  10. Pitz, W. J. and Westbrook, C. K., 1986, 'Chemical Kinetics of the High Pressure Oxidation of M-Butane and Its Relation to Engine Knock', Combustion and Flame, Vol. 63, pp. 113-133 https://doi.org/10.1016/0010-2180(86)90115-X
  11. Ranzi, E., Faravelli, T, . Gaffuri, P., Pennati, G. C. and Sogaro, A., 1994, 'A Wide Range Modeling Study of Propane and n-Butane Oxidation', Combust. Sci. and Tech., Vol. 100. pp. 299-330 https://doi.org/10.1080/00102209408935458
  12. Sazhin, S. S., Sazhina, E. M. and Heikal, M. R., 1999, 'The Shell Autoignition Model: A New Mathematical Formulation,' Combustion and Flame, Vol. 117. pp. 529-540 https://doi.org/10.1016/S0010-2180(98)00072-8
  13. Westbrook, C. K., Curran, H. J., Pitz, W. J., Griffiths, J. P., Mohamed, C. and Wo, S. K., 1998, 'The Effects of Pressure, Temperature, and Con centration on the Reactivity of Alkanes : Experiments and Modeling in a Rapid Compression Machine', The 27th Symposium International on Combustion, pp. 371-378