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Chemical Kinetics Study on Effect of Pressure and Fuel, O 2 and N 2 Molar Concentrations on Hydrocarbon Ignition Process
Technical Paper
2012-01-1113
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Ignition process chemistry was analyzed using a detailed chemical kinetic model of n-heptane generated by KUCRS (Knowledge-basing Utilities for Complex Reaction Systems), wherein pressure-dependent rate constants of the O₂ addition to alkyl radicals and hydroperoxy alkyl radicals and the thermal decomposition of ketohydroperoxides have been introduced. Then, the effect of the initial pressure and the individual effects of the initial fuel, O₂ and N₂ molar concentrations on a relationship between the initial temperature and the ignition delay were discussed. When the initial temperature increases, the branch of C₇H₁₄OOH removal into the second O₂ addition and the decomposition into C₇H₁₄cyO and OH is more sensitive to the pressure and the O₂ concentration, and thus, the LTO preparation phase is more affected by the pressure and the O₂ concentration. The LTO phase terminates mainly by the OH removal by intermediate species. When the pressure and the O₂ concentration increase, the activated second O₂ addition to C₇H₁₄OOH causes intermediate species to accumulate less efficiently, and thus, the LTO end temperature to increase. A period of the thermal ignition preparation phase is controlled by the rate of H₂O₂ (+ M) = OH + OH (+ M). When the pressure increases, the rate of this reaction increases by the dependence order of about 2, and due to the proportional increase in the whole gas concentration, the ignition delay shortens by the dependence order of about 1 in the blue-flame dominant region.
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Kuwahara, K., Hiramura, Y., Ohmura, S., Furutani, M. et al., "Chemical Kinetics Study on Effect of Pressure and Fuel, O2 and N2 Molar Concentrations on Hydrocarbon Ignition Process," SAE Technical Paper 2012-01-1113, 2012, https://doi.org/10.4271/2012-01-1113.Also In
References
- Sokolik, A. S. Self-Ignition, Flame and Detonation in Gases Israel Program for Scientific Translations Jerusalem 1963
- Ohta, Y. Hayashi, A. K. Fujiwara, T. Takahashi, H. n-Butane Ignition in a Wide Range of Temperature Progress in Aeronautics and Astronautics, AIAA 113 225 237 1988
- Furutani, M. Isogai, T. Ohta, Y. “Ignition Characteristics of Gaseous Fuels and Their Difference Elimination for SI and HCCI Gas Engines,” SAE Technical Paper 2003-01-1857 2003 10.4271/2003-01-1857
- Langridge, S. Fessler, H. “Strategies for High EGR Rates in a Diesel Engine,” SAE Technical Paper 2002-01-0961 2002 10.4271/2002-01-0961
- Zheng, J. Miller, D. Cernansky, N. Liu, D. et al. “The Effect of Active Species in Internal EGR on Preignition Reactivity and on Reducing UHC and CO Emissions in Homogeneous Charge Engines,” SAE Technical Paper 2003-01-1831 2003 10.4271/2003-01-1831
- Takada, K. Kusaka, J. “Numerical Analysis of Diesel Combustion with High EGR and High Boost Pressure using a Multi-Dimensional CFD Code Coupled with Complex Chemistry Analysis,” SAE Int. J. Fuels Lubr. 1 1 1037 1048 2009 10.4271/2008-01-1637
- Goldsborough, S. S. A Chemical Kinetically Based Ignition Delay Correlation for iso-Octane Covering a Wide Range of Conditions Including the NTC Region Combustion and Flame 156 6 1248 1262 2009
- Pilling, M. J. Low-Temperature Combustion and Autoignition Comprehensive Chemical Kinetics 35 Elsevier 1997
- Curran, H. J. Gaffuri, P. Pitz, W. J. Westbrook, C. K. A Comprehensive Modeling Study of n-Heptane Oxidation Combustion and Flame 114 149 177 1998
- Curran, H. J. Gaffuri, P. Pitz, W. J. Westbrook, C. K. A Comprehensive Modeling Study of iso-Heptane Oxidation Combustion and Flame 129 253 280 2002
- https://www-pls.llnl.gov/?url=science_and_technology-chemistry-combustion-prf
- Kuwahara, K. Ando, H. “Role of Heat Accumulation by Reaction Loop Initiated by H2O2 Decomposition for Thermal Ignition,” SAE Technical Paper 2007-01-0908 2007 10.4271/2007-01-0908
- Ando, H. Sakai, Y. Kuwahara, K. “Universal Rule of Hydrocarbon Oxidation,” SAE Technical Paper 2009-01-0948 2009 10.4271/2009-01-0948
- Ando, H. Kuwahara, K. Evaluation of Reaction Scheme at High Temperature Condition Bypassing Low-Temperature Reaction International Journal of Engine Research 10 6 389 398 2009
- Ando, H. Ohta, Y. Kuwahara, K. Sakai, Y. What is X in Livengood-Wu Integral? Review of Automotive Engineering 30 4 363 370 2009
- Ando, H. Sakai, Y. Kuwahara, K. The Thermal Ignition of Hydrocarbon-Fuel is not Controlled by H 2 -O 2 System Chemistry (in Japanese) Transactions of Society of Automotive Engineers of Japan 40 6 1557 1562 2009
- Kuwahara, K. Nakahara, K. Wada, Y. Senda, J. et al. “Chemical Kinetics Study on Ignition Characteristics of Biodiesel Surrogates,” SAE Technical Paper 2011-01-1926 2011 10.4271/2011-01-1926
- Miyoshi, A. Development of an Auto-generation System for Detailed Kinetic Model of Combustion (in Japanese) Transactions of Society of Automotive Engineers of Japan 36 5 35 40 2005
- http://www.frad.t.u-tokyo.ac.jp/∼miyoshi/KUCRS/index.htm.en
- Miyoshi, A. Systematic Computational Study on the Unimolecular Reactions of Alkylperoxy (RO 2 ), Hydroperoxyalkyl (QOOH), and Hydroperoxyalkylperoxy (O 2 QOOH) Radicals The Journal of Physical Chemistry A 115 3301 3325 2011
- Miyoshi, A. Molecular Size Dependent Falloff Rate Constants for the Recombination Reactions of Alkyl Radicals with O 2 and Implications for Simplified Kinetics of Alkylperoxy Radicals International Journal of Chemical Kinetics 44 1 59 74 2012
- Blumenthal, R. Fieweger, K. Adomeit, G. Self-ignition of S.I. Engine Model Fuels: A Shock Tube Investigation at High Pressure Combustion and Flame 109 4 599 619 1997