Kinetic Modelling and Model based Control of SCR Deposit

Abstract

Selective catalytic reduction (SCR) is widely used for on-highway as well as off-road applications to fulfil stringent nitrogen oxide (NOX) emission standards. However, in the practical operations, urea deposits occur under unfavourable conditions, which bring about urea dosing strategy failures, affect SCR system de-NOX performance and decrease fuel economy by increase engine back pressure. This paper presents a 1D kinetic model of SCR system, which can predict SCR reaction and deposit formation process. Furthermore, a model-based control strategy has been designed for real engine applications. The ETC test shows the deposits quantity can be reduced by 41.8% with this model.