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Next Generation All in One Close-Coupled Urea-SCR System
Technical Paper
2015-01-0994
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Diesel engines provide a solution for the reduction of carbon dioxide (CO2) from motor vehicles. For diesel engines, however, technology to reduce nitrogen oxide (NOx) emissions is essential. This report focuses on Urea - Selective Catalytic Reduction (SCR) as an aftertreatment system for NOx reduction.
The NOx conversion performance of SCR catalyst depends on exhaust gas temperature and the NO2/NOX ratio. In order to raise the NO2/NOX ratio, it is essential to raise the temperature of oxidation catalyst. For these purposes, it is necessary to raise the temperature of oxidation catalyst and SCR catalyst to high level in order to enhance NOx conversion. Temperature rising is implemented by in-cylinder fuel injection (post-injection). Consequently, degraded fuel economy becomes an issue at low vehicle speeds that cannot be expected to raise the temperature in catalyst, and particularly in the case of conventional SCR system that is located under the vehicle floor (Under-Floor SCR: UF/SCR). As one technology, a diesel particulate filter (DPF) that is close-coupled to the engine coated with SCR catalyst (SCR coated on DPF : SCR/F) has been proposed to address this issue so that the SCR catalyst temperature will be higher, and therefore reducing the fuel penalty. The present research considered ways to enhance the performance of the hardware element technology of such an SCR/F system, and this paper reports on the results.
As a result, after the characteristics of the element technologies of the SCR/F system had been ascertained, SCR catalyst was added and mixer specifications were improved so as to create a system that combined all the elements in a single converter. This effort successfully identified specifications that enhance NOx conversion performance while finding a balance with soot combustion performance and pressure loss characteristics.
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Kojima, H., Fischer, M., Haga, H., Ohya, N. et al., "Next Generation All in One Close-Coupled Urea-SCR System," SAE Technical Paper 2015-01-0994, 2015, https://doi.org/10.4271/2015-01-0994.Also In
References
- Fischer , M. , Kojima , H. , Mito , T. , Ohya , N. , Haga , H. , Sato , N. Efficiency Optimization of SCR Coated Particle Filters 23 rd Aachen Colloquium Automobile and Engine Technology Germany 2014
- Fischer , M. Potential and Challenges of SCR coated Particle Filters 8 th international CTI Forum SCR Systems Germany July 3 4 2012
- Yasui , Y. , Hashimoto , E. , Matsunaga , H. , Hardam , H. et al. A New Clean Diesel Concept for US LEV-III SULEV. First Report: A New Emission Strategy and Aftertreatment Management Control 4 th MinNOX conference Germany June 12 13 2012
- Haga , H. , Hashimoto , E. , Nakajima , K. , Matsunaga , H. et al. Advanced Urea-SCR Control for Next Generation Clean Diesel Vehicle FISITA 2014 World Congress Netherlands June 2 6 2014
- Haga , H. , Hashimoto , E. , Nakajima , K. , Matsunaga , H. et al. New Concept Urea-SCR Control for Super Clean Diesel Vehicle 7 th IFAC Symposium on Advances in Automotive Control Japan September 4 7 2013
- Alano , E. , Jean , E. , Perrot , Y. , Brunel , J. et al. Compact SCR for Passenger Cars SAE Technical Paper 2011-01-1318 2011 10.4271/2011-01-1318
- Michelin , J. , Guilbaud , F. , Guil , A. , Newbigging , I. et al. Advanced Compact SCR Mixer: BlueBox SAE Technical Paper 2014-01-1531 2014 10.4271/2014-01-1531
- Murata , Y. , Tajiri , K. , Sasaki , Y. , Fukushima , H. et al. Development of the New 2.2l Fuel-Efficient Diesel Engine for Honda Civic 21st Aachen colloquium Automobile and Engine Technology Germany 2012
- Tan , J. , Solbrig , C. , and Schmieg , S. The Development of Advanced 2-Way SCR/DPF Systems to Meet Future Heavy-Duty Diesel Emissions SAE Technical Paper 2011-01-1140 2011 10.4271/2011-01-1140
- Guo , G. , Dobson , D. , Warner , J. , Ruona , W. et al. Advanced Urea SCR System Study with a Light Duty Diesel Vehicle SAE Technical Paper 2012-01-0371 2012 10.4271/2012-01-0371
- Naseri , M. , Chatterjee , S. , Castagnola , M. , Chen , H. et al. Development of SCR on Diesel Particulate Filter System for Heavy Duty Applications SAE Int. J. Engines 4 1 1798 1809 2011 10.4271/2011-01-1312