A novel NH3 slip control for diesel engine selective catalytic reduction aftertreatment system.

To meet the future emission legislations, selective catalytic reduction aftertreatment system becomes a leading aftertreatment technique for heavy-duty diesel engines. In this article, a two-cell selective catalytic reduction model is first calibrated and verified on an experimental test bench. In order to regulate the ammonia coverage ratio in a proper range, an ammonia storage control is proposed based on the selective catalytic reduction model. The problem of NH₃ slip during temperature rise is discussed and a corresponding perturbation injection control is proposed to buffer the sudden change in selective catalytic reduction ammonia storage capability. The NH₃ slip control performance of the proposed strategy is experimentally validated in European Transient Cycle. [ABSTRACT FROM AUTHOR]