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Advanced Spray Impingement Modelling for an Improved Prediction Accuracy of the Ammonia Homogenisation in SCR Systems
Technical Paper
2015-01-1054
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
A fast preparation of the liquid urea water solution (UWS) is necessary to ensure high conversion rates in exhaust aftertreatment systems based on Selective Catalytic Reduction (SCR). Droplet wall interaction is of major importance during this process, in particular droplet breakup and the Leidenfrost effect. A deeper understanding of the underlying mechanisms is a basic requirement to calibrate CFD models in order to improve their prediction accuracy.
This paper presents a detailed literature study and discussion about the major impact factors on droplet wall interaction. Measurements of the Leidenfrost temperature were conducted and the corresponding regimes classified based on optical observations. The pre- and post-impingement spray was analysed using the laser diffraction method. Further, the validity of spray initialisation based on measurements at room temperature was verified. The Leidenfrost effect, partial droplet evaporation, droplet breakup and evaporation at the catalyst are the crucial aspects of impingement modelling. Their implementation and calibration against measurement data is presented. Sensitivity studies of single impact factors were carried out based on two exhaust systems that are representative for the spectrum of typical automotive applications. A set of operating points was used that covers the whole range of typical operating conditions. Finally, a best practice setup was derived and validated with measured ammonia distributions.
With the help of the presented numerical and experimental investigations the prediction accuracy of the simulated ammonia homogenisation could be significantly increased for inherently different exhaust pipe geometries.
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Smith, H., Zöchbauer, M., and Lauer, T., "Advanced Spray Impingement Modelling for an Improved Prediction Accuracy of the Ammonia Homogenisation in SCR Systems," SAE Technical Paper 2015-01-1054, 2015, https://doi.org/10.4271/2015-01-1054.Also In
References
- Johnson , T. Vehicular Emissions in Review SAE Int. J. Engines 7 3 1207 1227 2014 10.4271/2014-01-1491
- Knirsch , S. , Weiss , U. , Möhn , S. , Pamio , G. Die neue V6-TDI-Motoren-Generation von Audi Teil 2: Thermodynamik, Applikation und Abgasnachbehandlung MTZ -Motortechnische Zeitschrift 75 10 48 55 2014 10.1007/s35146-014-0575-2
- Neusser , H.-J. , Kahrstedt , J. , Dorenkamp , R. , Jelden , H. Die Euro-6-Motoren des Modularen Dieselbaukastens von Volkswagen MTZ - Motortechnische Zeitung 74 6 440 447 2013 10.1007/s35146-013-0125-3
- Ruth , M. Cummins' Next Generation Tier 2, Bin 2 Light Truck Diesel Engine Directions in Engine-Efficiency and Emissions Research Conference Dearborn, USA 2012
- Herrmann , H.-O. , Nielsen , B. , Gropp , C. , Lehmann , J. Mittelschwerer NFZ-Motor von Mercedes-Benz Teil 1: Motor- und Abgasreinigungskonzept MTZ - Motortechnische Zeitung 73 10 730 738 2013 10.1007/s35146-012-0473-4
- Abu-Ramadan , E. , Saha , K. , Li , X. Modeling the Depleting Mechanism of Urea-Water-Solution Droplet for Automotive Selective Catalytic Reduction Systems AIChE Journal 57 3210 3225 2011 10.1002/aic.12523
- Ebrahimian , V. , Nicolle , A. , and Habchi , C. Detailed Modeling of the Evaporation and Thermal Decomposition of Urea-Water Solution in SCR Systems AIChE Journal 58 7 1998 2009 2012 10.1002/aic.12736
- Koebel , M. , and Strutz , E.O Thermal and Hydrolytic Decomposition of Urea for Automotive Selective Catalytic Reduction Systems: Thermochemical and Practical Aspects Industrial & Engineering Chemistry Research 42 2093 2100 2003 10.1021/ie020950o
- Fischer , S. , Bitto , R. , Lauer , T. , Krenn , C. et al. Impact of the Turbulence Model and Numerical Approach on the Prediction of the Ammonia Homogenization in an Automotive SCR System SAE Int. J. Engines 5 3 1443 1458 2012 10.4271/2012-01-1291
- Smith , H. , Lauer , T. , Mayer , M. , and Pierson , S. Optical and Numerical Investigations on the Mechanisms of Deposit Formation in SCR Systems SAE Int. J. Fuels Lubr. 7 2 525 542 2014 10.4271/2014-01-1563
- Bai , C. and Gosman , A. Development of Methodology for Spray Impingement Simulation SAE Technical Paper 950283 1995 10.4271/950283
- Bai , C.X , Rusche , H. , Gosman , A.D Modelling of Gasoline Spray Impingement Atomization and Sprays 01 2002 10.1615/AtomizSpr.v12.i123.10
- Kuhnke , D. Spray/Wall-Interaction Modelling by Dimensionless Data Analysis Technische Universität Darmstadt 2004
- Birkhold , F. Selektive katalytische Reduktion von Stickoxiden in Kraftfahrzeugen: Untersuchung der Einspritzung von Harnstoffwasserlösung PhD thesis Universität Karlsruhe 2007
- Fischer , S. Simulation of the Urea-Water-Solution Preparation and Ammonia-Homogenization with a Validated CFD-Model for the Optimization of Automotive SCR-Systems PhD thesis Vienna University of Technology 2012
- Zheng , G. , Fila , A. , Kotrba , A. , and Floyd , R. Investigation of Urea Deposits in Urea SCR Systems for Medium and Heavy Duty Trucks SAE Technical Paper 2010-01-1941 2010 10.4271/2010-01-1941
- Birkhold , F. , Meingast , U. , Wassermann , P. , and Deutschmann , O. Analysis of the Injection of Urea-Water-Solution for Automotive SCR DeNOx-Systems: Modeling of Two-Phase Flow and Spray/Wall-Interaction SAE Technical Paper 2006-01-0643 2006 10.4271/2006-01-0643
- Fest-Santini , S. Wärmeübergang bei der Sprühkühlung mit intermittierenden Sprays oberhalb der Leidenfrosttemperatur PhD thesis Universität Magdeburg 2009
- Kontin , S. , Höfler , A. , Koch , R. , and Bauer , H.-J. Heat and Mass Transfer accompanied by Crystallisation of single Particles containing Urea-water-solution ILASS - Europe2010, 23rd Annual Conference on Liquid Atomization and Spray Systems Brno, Czech Republic 2010
- Musa , S. , Masahiro , S. , Furuhata , T. , Arai , M. Evaporation characteristics of a single aqueous urea solution droplet Paper-ID ICLASS06-195, ICLASS-2006 Conference Kyoto, Japan 2006
- CD-adapco Methodology STAR-CD VERSION 4.16 2011
- Nishioka , A. , Sukegawa , Y. , Katogi , K. , Mamada , H. et al. A Study of a New Aftertreatment System (2): Control of Urea Solution Spray for Urea-SCR SAE Technical Paper 2006-01-0644 2006 10.4271/2006-01-0644
- Dunand , P. , Castanet , G. , Gradeck , M. , Maillet , D. , Lemoine , F. Energy balance of droplets impinging onto a wall heated above the Leidenfrost temperature International Journal of Heat and Fluid Flow 44 170 180 2013 10.1016/j.ijheatfluidflow.2013.05.021
- Bernardin , J.D , Mudawar , I. The Leidenfrost Point: Experimental Study and Assessment of Existing Models Journal of Heat Transfer 121 4 894 903 1999 10.1115/1.2826080
- van Vuuren , N. and Sayar , H. High Speed Video Measurements of a Heated Tip Urea Injector Spray SAE Technical Paper 2012-01-1747 2012 10.4271/2012-01-1747
- van Vuuren , N. and Qin , J. High Speed Video Measurements with Water of a Planar Laser Illuminated Heated Tip Urea Injector Spray SAE Technical Paper 2013-01-1073 2013 10.4271/2013-01-1073
- Kiedaisch , J.W , Gravante , S.P Calibration of CFD Spray Model Parameters Using Detailed Experimental Spray Characterization Data ICLASS 2009 USA 2009
- Puschmann , F. Experimentelle Untersuchung der Spraykühlung zur Qualitätsverbesserung durch definierte Einstellung des Wärmeübergangs PhD thesis Universität Magdeburg 2003
- Schaber , P.M , Colson , J. , Higgins , S. , Thielen , D. , Anspach , B. , and Brauer , J. Thermal decomposition (pyrolysis) of urea in an open reaction vessel Thermochimica Acta 424 131 142 2004 10.1016/j.tca.2004.05.018
- VDI-Gesellschaft Verfahrenstechnik und Chemieingenieurwesen VDI-Wärmeatlas 10th VDI-Verlag 2006
- Munnannur , A. , Chiruta , M. , and Liu , Z. Thermal and Fluid Dynamic Considerations in Aftertreatment System Design for SCR Solid Deposit Mitigation SAE Technical Paper 2012-01-1287 2012 10.4271/2012-01-1287
- Maass , J. , Eppler , A. , Scholz , J. , Gentgen , H. , Grumbrecht , F. , Marohn , R. Influences of AdBlue spray targeting and mixing devices on the UWS distribution upstream of the SCR catalyst Proceedings of IMechE - Fuel Systems for IC Engines 21 41 IMechE London, UK March 2012
- Lenz , H. P Mixture Formation in Spark-Ignition Engines Springer-Verlag Wien 1992
- Ström , H. , Lundström , A. , Andersson , B. Choice of urea-spray models in CFD simulations of urea-SCR systems Chemical Engineering Journal 150 69 82 2009 10.1016/j.cej.2008.12.003
- Das , S. , Das , K. , Abidin , Z. , and Mehta , D. Effects of Various Model Parameters in the Simulation of a Diesel SCR System SAE Technical Paper 2012-01-1297 2012 10.4271/2012-01-1297
- Kompinsky , E. , Dolan , G. , Sher , E. Experimental study on the dynamics of binary fuel droplet impacts on a heated surface Chemical Engineering Science 98 186 194 2013 10.1016/j.ces.2013.04.047
- Wruck , N. Transientes Sieden von Tropfen beim Wandaufprall PhD thesis RWTH Aachen 1998
- Stiesch , G. Modeling Engine Spray and combustion Processes 1st Springer Verlag 2003
- Silva , A. , Barata , J. , Rodrigues , C. Influence of the Spread/Splash Transition Criteria in the Spray Impingement Modeling Journal of Energy and Power Engineering 7 290 300 2013
- Lee , M.M , Hanratty , T.J The Inhibitation of Droplet Deposition by the Presence of a Liquid Film Int. J. Multiphase Flow 14 2 129 149 1988 10.1016/0301-9322(88)90001-8
- Yarin , A.L , Weiss , D.A Impact of drops on solid surfaces: self-similar capillary waves, and splashing as a new type of kinematic discontinuity J. Fluid Mech. 283 141 173 1995 10.1017/S0022112095002266
- Malvern Indstruments Limited A Basic Guide to Particle Characterisation 2012
- Zöchbauer , M. , Fischer , S. , Lauer , T. , Siegmann-Hegerfeld , T. et al. Validation of Turbulence Models for an Automotive SCR System with Laser Doppler Anemometry Measurements SAE Technical Paper 2013-01-1579 2013 10.4271/2013-01-1579
- Zöchbauer , M. , Smith , H. , and Lauer , T. Advanced SCR Flow Modeling with a validated Large Eddy Simulation SAE Technical Paper 2015-01-1046 2015 10.4271/2015-01-1046
- Zheng , G. , Sampath , M. , Alcini , W. , Salanta , G. et al. Design Improvements of Urea SCR Mixing for Medium-Duty Trucks SAE Technical Paper 2013-01-1074 2013 10.4271/2013-01-1074