Multi-Scale SCR Modeling, 1D Kinetic Analysis and 3D System Simulation

Future emission limits of diesel engines require additional effort for developing adequate and advanced exhaust gas aftertreatment devices. Urea-SCR systems are a promising approach to reduce nitric oxide emissions. Computer models as a complementary tool to experimental investigations help to make design decisions and to shorten the development process. Therefore, this work presents a comprehensive SCR simulation approach. All relevant conversion reactions are studied in a 1d model. The obtained parameters are transferred to 3d simulations and combined with a detailed description of the urea injection. Validation simulations are performed for the individual SCR reactions and show good agreement with experimental data. 1d studies of different SCR assemblies and sizes are presented. Full 3d simulations of an HSO system considering injection, homogeneous gas phase and catalytic reaction show the interaction of all relevant effects and their impact on the overall deNOx performance.