Analysis of the Injection of Urea-Water-Solution for Automotive SCR DeNOx-Systems: Modeling of Two-Phase Flow and Spray/Wall-Interaction

The selective catalytic reduction (SCR) based on ureawater-solution is an effective technique to reduce nitrogen oxides (NOx) emitted from diesel engines. A 3D numerical computer model of the injection of urea-water-solution and their interaction with the exhaust gas flow and exhaust tubing is devel...

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Bibliographic Details
Published in:SAE transactions 2006-01, Vol.115, p.252-262
Main Authors: Birkhold, Felix, Meingast, Ulrich, Wassermann, Peter, Deutschmann, Olaf
Format: Article
Language:English
Online Access:Get full text
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Summary:The selective catalytic reduction (SCR) based on ureawater-solution is an effective technique to reduce nitrogen oxides (NOx) emitted from diesel engines. A 3D numerical computer model of the injection of urea-water-solution and their interaction with the exhaust gas flow and exhaust tubing is developed to evaluate different configurations during the development process of such a DeNOxsystem. The model accounts for all relevant processes appearing from the injection point to the entrance of the SCR-catalyst: • momentum interaction between gas phase and droplets • evaporation and thermolysis of droplets • hydrolysis of isocyanic acid in gas phase • heat transfer between wall and droplets • spray/wall-interaction • two-component wall film including interaction with gas phase and exhaust tube The single modeling steps are verified with visualizations, patternator measurements, phase-doppler-anemometer results and temperature measurements. CFD simulations of a SCR DeNOx-system are compared to experimental data to determine the decomposition parameters for ureawater-solution droplets. Numerical results for an injection including all processes addressed above are discussed.
ISSN:0096-736X
2577-1531