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CFD Investigation of the Impact of Electrical Heating on the Light-off of a Diesel Oxidation Catalyst
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2018 by SAE International in United States
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In the last years, as a response to the more and more restrictive emission legislation, new devices (SRC, DOC, NOx-trap, DPF) have been progressively introduced as standard components of modern after-treatment system for Diesel engines. In addition, the adoption of electrical heating is nowadays regarded with interest as an effective solution to promote the light-off of the catalyst at low temperature, especially at the start-up of the engine and during the low load operation of the engine typical of the urban drive.
In this work, a state-of-the-art 48 V electrical heated catalyst is considered, in order to investigate its effect in increasing the abatement efficiency of a standard DOC. The electrical heating device considered is based on a metallic support, arranged in a spiral layout, and it is heated by the Joule effect due to the passage of the electrical current. As a result of the spiral arrangement, the distribution of the heat source on the heating section is not uniform, determining a certain spatial distribution of the temperature of the gas entering the DOC section. This has also an influence on the pollutant conversion, both in term of light-off time and overall conversion. In order to simulate the after-treatment system, a suitable CFD framework has been implemented on the basis of the open-source OpenFOAM code. In particular, it is based on a multi-region approach, where overlapping meshes, describing fluid and solid regions, are employed in order to model the presence of porous substrates. Specific models are implemented in order to couple fluid and solid regions in terms of heat-transfer and mass-transfer. Catalytic reaction model is introduced in order to describe the chemical surface reactions occurring on the washcoat of the porous substrate.
The model is firstly validated resorting to experimental data. Then, it is applied for the investigation of the effects of the electrical heating on the pollutant abatement, with particular focus on the effects of the non-uniform temperature distribution related to different layouts of the heating spirals. The study points out the benefits related to the adoption of the electrical heating in terms of reduction of the overall pollutant emissions over the RDE cycle. Moreover, the effects of the non-uniform heating is investigated, showing a certain role in promoting the light-off of the reactions as a consequence of the formation of hot spots in the catalyst.
CitationDella Torre, A., Montenegro, G., Onorati, A., and Cerri, T., "CFD Investigation of the Impact of Electrical Heating on the Light-off of a Diesel Oxidation Catalyst," SAE Technical Paper 2018-01-0961, 2018, https://doi.org/10.4271/2018-01-0961.
Data Sets - Support Documents
|Unnamed Dataset 1|
|Unnamed Dataset 2|
- Johnson , T. Diesel Emissions in Review SAE Int. J. Engines 4 1 143 157 2011 10.4271/2011-01-0304
- Pfahl , U. , Schatz , A. , and Konieczny , R. Advanced Exhaust Gas Thermal Management for Lowest Tailpipe Emissions - Combining Low Emission Engine and Electrically Heated Catalyst SAE Technical Paper 2012-01-1090 2012 10.4271/2012-01-1090
- Della Torre , A. , Lucci , F. , Montenegro , G. , Onorati , A. et al. CFD Modeling of Catalytic Reactions in Open-Cell Foam Substrates Computers & Chemical Engineering 92 55 63 2016 10.1016/j.compchemeng.2016.04.031
- Montenegro , G. and Onorati , A. 1D Thermo-Fluid Dynamic Modeling of Reacting Flows inside Three-Way Catalytic Converters SAE Int. J. Engines 2 1 1444 1459 2009 10.4271/2009-01-1510
- OpenFOAM http://www.openfoam.org/docs/
- Weller , H.G. , Tabor , G. , Jasak , H. , and Fureby , C. A Tensorial Approach to CFD using Object Orientated Techniques Computers in Physics 12 6 620 1998
- Versteeg , H.K. and Malalasekera , W. An Introduction to Computational Fluid Dynamics Longman Scientific & Technical 1995
- Churchill , S.W. Comprehensive Correlating Equations for Heat, Mass and Momentum Transfer in Fully Developed Flow in Smooth Tubes Ind. Eng. Chem. Fundam. 16 109 116 1977 10.1021/i160061a021
- Lucci , F. , Della Torre , A. , Montenegro , A. , and Dimopoulos Eggenschwiler , P. On the Catalytic Performance of Open Cell Structures Versus Honeycombs Chemical Engineering Journal 264 514 521 2015 10.1016/j.cej.2014.11.080
- Tsinoglou , D.N. , Koltsakis , G.C. , and Peyton Jones , J.C. Oxygen Storage Modeling in Three-way Catalytic Converters Ind. Eng. Chem. Res. 41 5 1152 1165 2002 10.1021/ie010576c
- Patankar , S.V. Numerical Heat Transfer and Fluid Flow CRC Press 1980
- Della Torre , A. , Montenegro , G. , Cerri , T. , and Onorati , A. A 1D/Quasi-3D Coupled Model for the Simulation of I.C. Engines: Development and Application of an Automatic Cell-Network Generator SAE Int. J. Engines 10 2 471 482 2017 10.4271/2017-01-0514