New Urea-SCR Control System for Super Clean Diesel
Hisao Haga, Eiji Hashimoto, Koichi Nakajima, Hideki Matsunaga, and Yuji Yasui
Honda R&D Co., Ltd.
4630 Shimotakanezawa, Haga-machi, Haga-gun, Tochigi 321-3393, Japan
Diesel engines effectively reduce automotive CO2 emissions. Technologies for reducing NOx emissions are also essential, however, for diesel engine use. The research discussed in this paper focuses on urea-SCR as after-treatment system for converting NOx, and proposes the urea-SCR control based on NH3 sensor output. The NH3 sensor effectively reduces both NOx, and NH3 slip. The control adjusts the amount of urea dosed to the catalyst based on changes in NH3 slip timing and NH3 concentration in order to compensate for part-to-part variations in the SCR catalyst and catalyst aging. The proposed urea-SCR system using the NH3 sensor and applied to a test vehicle increased NOx conversion performance and improved emission robustness over that of conventional control using a NOx sensor.
-  M. Fischer, “Application of SCR Systems for Diesel PC -- Potential Challenges and Solutions,” presented at 7th Int. CTI Forum SCR Systems, Germany, July 5-6, 2011.
-  T. Hagimoto, “Development of Urea SCR catalyst monitoring method,” JSAE Paper, No.168-20095740, 2009.
-  R. Cloudt, “Meeting Future Emission Legislation with Advanced Diesel SCR Catalyst Control Systems,” JSAE Paper, No.126-20095307, 2009.
-  K. McMahon, “American Road: Clean Diesels for the Real World,” 2008 Diesel Engine-Efficiency and Emissions Research (DEER) Conf., 2008.
-  H. Onodera, “Development of a Diesel Emission Catalyst System for Meeting US SULEV Standards,” SAE Paper No.2008-01-0449, 2008.
-  M. Paule, “Challenges for the Next Generation of BlueTEC Emission Technology,” SAE Paper No.2011-01-0294, 2011.
-  Y. Murata, S. Tokui, S. Watanabe, Y. Daisho, H. Suzuki, and H. Ishii, “Improvement of NOx Reduction Rate of Urea-SCR System by NH3 Adsorption Quantity Control,” SAE Paper No.2008-01-2498, 2008.
-  K. Hirata, N. Masaki, H. Ueno, and H. Akagawa, “Development of Urea-SCR System for Heavy-Duty Commercial Vehicles,” SAE Paper No.2005-01-1860, 2005.
-  C. Ishihara, “Development of Urea SCR System on MAZDA CX-7,” MAZDA Technical Review 2010 (No.28), pp. 44-48, MAZDA, Hiroshima, Japan, July 2010, 2010.
-  A. Herman, M. Wu, D. Cabush, and M. Shost, “Model Based Control of SCR Dosing and OBD Strategies with Feedback from NH3 Sensors,” SAE Paper No.2009-01-0911, 2009.
-  M. Shost, J. Noetzel, M. Wu, T. Sugiarto, T. Bordewyk, G. Fulks, and G. Fisher, “Monitoring, Feedback and Control of Urea SCR Dosing Systems for NOx Reduction: Utilizing an Embedded Model and Ammonia Sensing,” SAE Paper No.2008-01-1325, 2008.
-  A. Herman, “Model Based Control of SCR Dosing and OBD strategies with Feedback from NH3 Sensors,” SAE World Congress, No.2009-01-0911, 2009.
-  D. Wang, S. Yao, M. Shost, J. Yoo, D. Cabush, D. Racine, R. Cloudt, and F. Willems, “Ammonia Sensor for Closed-Loop SCR Control,” SAE Paper No.2008-01-0919, 2008.
-  M. Sakota, N. Satoh, and H. Matsunaga, “Study of NOx Reduction Behavior on Iron Ion-exchanged Zeolite Catalyst for ULEV50,” Honda Technical Review 2013 (No.25), pp. 109-118, Honda R&D, Tochigi, Japan, March 2013, 2013.
-  A. Grossale, “The Chemistry of the NO/NO2-NH3 “Fast” SCR Reaction over Fe-ZSM5 Investigated by Transient Reaction Analysis,” J. of Catalysis, Vol.256, pp. 312-322, 2008.
-  H. Matsunaga, “A Super Clean Diesel Technology for US LEV-SULEV,” JSAE Paper, No.244-20125267, 2012.
-  Y. Yasui, “A New Clean Diesel Concept for US LEV-III SULEV. First Report: A New Emission Strategy and Aftertreatment Management Control,” presented at 4th MinNOx Conf., Germany, June 12-13, 2012.
-  H. Haga, E. Hshimoto, K. Nakajima, H. Matsunaga, and Y. Yasui, “New Concept Urea-SCR Control for Super Clean Diesel Vehicle,” the 7th IFAC Symposium on Advances in Automotive Control, ThA1.4, September 2013, 2013.
-  M. Fischer, “Transient NOx Estimation using Artificial Neural Networks,” the 7th IFAC Symposium on Advances in Automotive Control, ThB1.3, September 2013, 2013.
-  M. Fischer, J. Boettcher, C. Kirkham, and R. Georgi, “OBD of diesel EGR using artificial neural networks,” SAE Paper No.2009-01-1427, 2009.
-  Y. Yasui, “A New Air-fuel Ratio Control for A High-Efficiency and Low-Emission Engine,” SICE J. of Control, Measurement, and System Integration, Vol.5, No.5, pp. 268-275, September 2012, 2012.