Methodology for calculating diesel SCR systems

Abstract

Selective catalytic reduction systems are widely applied as a NOX emission control technology in modern onand off highway diesel engines. Considering the stringent limits of emission standards, they should ensure high rates of conversion efficiency. To achieve that at the design stage numerical modelling is used to optimize physical and chemical processes. New mathematical models and methods that can provide the reduction of calculation time and related costs keeping the acceptable level of prediction accuracy are desired. In this study a methodology for calculating SCR systems based on the use both of CFD models and simplified catalyst models are presented. The capabilities of the suggested numerical approach were demonstrated during the simulations of a SCR system where the influence of UWS injection angle on NOX reduction efficiency was investigated.