Multiobjective Optimal Design of a Lean NO x Trap and Urealess Selective Catalytic Reduction Aftertreatment System under a Control Algorithm

A lean NO x trap (LNT) followed by selective catalytic reduction (SCR) without the urea injection system (LNT-urealess SCR, LNT-pSCR) has been developed to meet the stringent regulations on NO x emission. For the LNT-pSCR system to be commercialized, optimal design and control of the system are required. It is important to minimize the capital cost while satisfying the NO x regulation standards and minimizing fuel consumption. In this study, we propose a strategy to optimally design the lengths of the LNT and pSCR and tune control parameters by solving the multiobjective optimization problem and considering control logic simultaneously. For decision makers, NO x emission and capital cost are critical factors to consider. In addition, NH 3 slip and fuel loss caused by post injection must be considered. The Pareto optimal points are obtained by solving the biobjective optimization problem …