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3-D Numerical Study of Mixing Characteristics of NH3 in Front of SCR
Technical Paper
2006-01-3444
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The Urea Selective Catalytic Reduction (SCR) technology is one of the major mature exhaust aftertreatment technologies which are demonstrated to be able to lower tail pipe NOx emission by 90%. The system consists of a urea injection at upstream pipe and a downstream SCR converter. A well mixed flow (exhaust gas and NH3) in front of SCR substrate, which is usually constrained by tight design packaging, is very critical to ensure the desired performance. Current paper addresses the geometrical effects on flow mixing by using three dimensional Computational Fluid Dynamics (CFD) tool. The mixing enhancement is achieved by adding flow mixer. The shapes and locations of flow mixers, as well as the number of blades inside mixer are investigated to show the effect on fluid mixing in downstream along the flow direction. Results show great improvement of flow mixing by adding a delta wing mixer. The turbulent flow generated by delta wings is proved to be very useful for a significant mixing enhancement within a short distance. It is found that a flow mixer in front of injector results in higher flow mixing index right behind the mixer. Higher flow mixing indexes are found 200 mm downstream and beyond when mixer is located right behind injector. Besides turbulent flow, Swirling flow is another major contributor for higher flow mixing index. A simple flow mixer with twisted blades is constructed based on original delta wing mixer for the purpose of creating swirling flow as well as turbulent flow. It is found turbulent flow has dominant effect on flow mixing index in the short distance right behind the flow mixer while the swirling flow dominates contribution through a longer distance. It is surprise to see that flow mixing index is higher when the number of twisted blades is reduced from six to three.
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Zhang, X., Romzek, M., and Morgan, C., "3-D Numerical Study of Mixing Characteristics of NH3 in Front of SCR," SAE Technical Paper 2006-01-3444, 2006, https://doi.org/10.4271/2006-01-3444.Also In
References
- Hoard John Hammerle Robert Lambert Christine Wu George Economic Comparison of LNT Versus Urea SCR for Light Duty Diesel Vehicles in US Market DOE Diesel Engine Emission Reduction Meeting August 29 September 2 2004
- Scarnegie Miller Ballmert Doelling Fischer Recent DPF/SCR Results Targeting US2007 and Euro 4/5 HC Emission SAE 2003-01-0774
- Walker Blakemen Ilkenhans Magnusson McDonald Kleijwegt Stunnenberg Sanchez The Development and In-Field Demonstration of Highly Durable SCR Catalyst Systems SAE 2004-01-1289
- Tennison Lambert Levin NOx Control Development with Urea SCR on a Diesel Passenger Car SAE 2004-01-1291
- Schittler State-of-the-art and Emerging Truck Engine Technologies 9 th Diesel Engine Smission Reduction Conference Newport, RL August 2003
- Zhang Xiaogang Romzek Martin Keck Mathias Frank Kurz Numerical Optimization of Flow Uniformity inside Diesel Particular Filters SAE 2005-01-3702 2005
- Zhang Xiaogang Meda Lakshmikanth Keck Mathias Numerical Study on Skin Temperature and Heat Loss of Vehicle Exhaust System SAE 2005-01-1622 2005
- Jeong Soo-Jin Lee Sang-Jin Kim Woo-Seung Lee Chunboem Simulation on the Optimum Shape and Location of Urea Injector for Urea-SCR System of Heavy-Duty Diesel Engine to Prevent NH3 Slip SAE, 2005-01-3886 2005
- Chen Ming Williams Shazam Modeling and Optimization of SCR-Exhaust Aftertreatment Systems SAE, 2005-01-0969 2005
- Wurzenberger Johann C. Wanker Roland Multi-Scale SCR Modeling, 1d Kinetic Analysis and 3d System Simulation SAE, 2005-01-0948 2005
- Van Helden Rinie Verbeek Ruud P. Optimization of Urea SCR Denox Systems for HD Diesel Engines SAE, 2004-01-0154 2004
- Fluent 6.2 Fluent Inc. 2005