Advanced SearchSearch Tips
A Study of NH3 Adsorption/Desorption Characteristics and Model Based Control in the Urea-SCR System
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
A Study of NH3 Adsorption/Desorption Characteristics and Model Based Control in the Urea-SCR System
Ham, Yunyoung; Park, Suyeol;
  PDF(new window)
Urea-SCR system is currently regarded as promising NOx reduction technology for diesel engines. SCR system has to achieve maximal NOx conversion in combination with minimal slip. In this study, model based open loop control for urea injection was developed and assessed in the European Transient Cycle (ETC) for heavy duty diesel engine. On the basis of the transient modeling, the kinetic parameters of the adsorption and desorption are calibrated with the experimental results performed over the zeolite based catalyst. storage or surface coverage of SCR catalyst can not be measured directly and has to be calculated, which is taken into account as a control parameter in this model. In order to reduce slip while maintaining NOx reduction, storage control algorithm was applied to correct the basic urea quantity. If the actual surface coverage is higher than the maximal surface coverage, the urea injection quantity is significantly reduced in the ETC cycle. By applying this logic, the resulting slip peak can be avoided effectively. With optimizing the kinetic parameters based on standard SCR reaction, it suggests that a simplified, less accurate model can be effective to evaluate the capability of model based control in the ETC cycle.
ETC(European Transient Cycle);NOx;Urea; slip;SCR(Selective Catalyst Reduction); surface coverage;
 Cited by
H. Kojima, M. Fischer, H. Haga, N. Ohya, K. Nishi, T. Mito and N. Fukushi, "Next Generation All in One Close-Coulpled Urea-SCR System," SAE 2015-01-0994, 2015.

P. Chavannavar, "Development and Implementation of a Mapless, Model Based SCR Control System," SAE 2014-01-9050, 2014.

T. V. Johnson, "Review of Vehicular Emissions Trends," SAE 2015-01-0993, 2015.

A. Schuler, M. Votsmeier, P. Kiwic, J. Gieshoff, W. Hautpmann, A. Drochner and H. Vogel, "$NH_3$-SCR on Fe Zeolite Cataysts - from Model Setup to $NH_3$ Dosing," Chemical Engineering Journal, Vo1.154, Issues 1-3, pp.333-340, 2009. crossref(new window)

M. Colombo, G. Koltsakis, I. Nova and E. Tronconi, "Modelling the Ammonia Adsorptiondesorption Process Over an Fe-zeolite Catalyst for SCR Automotive Applications," Catalysis Today, Vol.188, No.1, pp.42-52, 2012. crossref(new window)

A. Herman, M. C. Wu, D. Cabush and M. Shost, "Model Based Control of SCR Dosing and OBD Strategies with Feedback from $NH_3$ Sensors," SAE 2009-01-0911, 2009.

T. Wang, S. Baek, M. Jung and G. Yeo, "A Study of $NH_3$ Adsorption/Desorption Characteristics in the Monolithic $NH_3$-SCR Reactor," Transactions of KSAE, Vol.14, No.3, pp.125-132, 2006.

M. Shost, J. Noetzel, M. C. Wu, T. Sugiarto, T. Bordewyk, G. Fulks and G. B. Fisher, "Monitoring, Feedback and Control of Urea SCR Dosing Systems for NOx Reduction : Utilizing an Embedded Model and Ammonia Sensing," SAE 2008-01-1325, 2008.

F. Willems, R. Cloudt, E. Eijnden, M. Genderen, R. Verbeek, B. Jager, W. Boomsma and I. Heuvel, "Is Closed-Loop SCR Control Required to Meet Future Emission Targets?," SAE 2007-01-1574, 2007.

D. H. E. Seher, M. Reichelt and S. Wickert, "Control Strategy for NOx - Emission Reduction with SCR," SAE 2003-01-3362, 2003.