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Post Oxidation Study During Secondary Exhaust Air Injection for Fast Catalyst Light-Off
ISSN: 0148-7191, e-ISSN: 2688-3627
Published November 02, 2009 by SAE International in United States
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To comply with ever more stringent emission limits, engineers are studying and optimising gasoline engine start-up and warm-up phases. Secondary air injection (SAI) represents one option to reduce emissions by post-oxidizing products of a rich combustion like HC, CO and H2. With this approach, the faster catalytic converter light-off allowed by the increase in exhaust temperature leads to a significant HC emissions reduction. All the mechanisms involved in post oxidation downstream of the exhaust valve are not well-known. In order to achieve substantial improvements, various SAI strategies were studied with a conventional PFI gasoline engine. Tests have been carried out both on steady-state running conditions and on transient warm-up phases at engine test bench. Various specific experimental devices and methodologies were developed. For example, the use of fast HC and temperature measurements is coupled with exhaust gas flow rate modeled with system simulation. This approach permits to study precisely the initiation and evolution of post oxidation at engine’s cycle scale. 3D CFD calculations have also been performed for understanding fresh air and burned gases mixing during the different exhaust phases as well as post-oxidation initiation and propagation. Additionally, sources and locations of heat release within the exhaust line have been quantified to make the difference between the power actually used to heat-up the catalytic converter and the heat losses. Owing to the better understanding of the complex phenomena taking place, fine tuning of engine and secondary air settings lead to significant improvement in catalyst heating up and HC tailpipe emissions reduction.
CitationSerrano, D., Lavy, J., Kleemann, A., Zinola, S. et al., "Post Oxidation Study During Secondary Exhaust Air Injection for Fast Catalyst Light-Off," SAE Technical Paper 2009-01-2706, 2009, https://doi.org/10.4271/2009-01-2706.
- Borland M. Zhao F. - Application of Secondary Air Injection for Simultaneous Reducing Converter-In Emissions and Improving Catalyst Light-Off Performance - SAE paper 2002-01-2803
- Koehlen C. Holder E. Vent G. - Investigation of Post Oxidation and Its Dependency on Engine Combustion and Exhaust Manifold Design - SAE paper 2002-01-0744 2002
- Hernandez J.L Herding G. Cartensen A. Spicher U. - A study of the thermo chemical conditions in the exhaust manifold using secondary air in a 2.0 L engine - SAE paper 2002-01-1676 2002
- Huang Y. Sung C.J. Eng J.A. - Effects of secondary air on global hydrocarbon consumption rates in engine exhaust gas - Combustion Science and Technology - 2005
- Lang K. R. Cheng W. K. - A novel strategy for fast catalyst light-off without the use of an air pump - SAE paper 2007-01-0044 2007
- Bratschiz B. Blümcke E. Fogt H. - CFD-simulation of the secondary air injection in the exhaust after-treatment system of the Audi 1.8L 5V engine - Proceedings of the European automotive congress - Paper n° SAITS 01165, Bratislava 18-20 June - 2001
- Zolver M. Klahr D. Bohbot J. Laget O. Torres A. Reactive CFD in engines with a new unstructured parallel solver - Oil 8 Gas Science and Technology 58 33 46 2003
- Han Z. Reitz R. D. Turbulence Modeling of Internal Combustion Engines using RNG k-ɛ Models Combustion Science and Technology 106 267 295 1995
- Angelberger, C. Poinsot, T. Delhaye, B. - Improving near-wall combustion and wall heat transfer modelling in SI engine computations - SAE paper 972881 1997
- Duclos J-M Colin O. Arc and Kernel tracking ignition for model for 3D spark-ignition engine calculations - Proceedings of the fifth international Symposium on Diagnostics and Modeling of Combustion in internal combustion engines (COMODIA 2001) 343 350 2001
- Colin O. Benkenida A. - The 3-zones extended coherent flame model (ECFM3Z) for computing premixed/diffusion combustion - Oil 8 Gas Science and Technology 59 593 609 2004
- Knop V. Jay S. - Latest developments in gasoline auto-ignition modelling applied to an optical CAI™ engine - Oil 8 Gas Science and Technology 61 121 138 2006
- Jay S. Beard P. Pires da Cruz A. Modeling Coupled Processes of CO and Soot Formation and Oxidation for Conventional and HCCI Diesel Combustion SAE Paper 2007-01-0162 2007
- Knop V. Kircher H. Jay S. Beard P. Pires da Cruz A. Colin O. Quantitative pollutant modelling: an essential prerequisite for Diesel HCCI and LTC engine design - Oil 8 Gas Science and Technology 63 495 516 2008
- Hautman D.J. Dryer F.L Schug K.P. Colin O. - A multiple step overall kinetic mechanism for the oxidation of hydrocarbons - Combustion Science and technology 25 219 235 1981