APPARATUS, SYSTEM, AND METHOD FOR CONTROLLING AMMONIA SLIP FROM AN SCR CATALYST

摘要

According to one representative embodiment, an apparatus (130) for reducing NOx emissions in an engine exhaust includes a NOx reduction target module (300) configured to determine a NOx reduction requirement (304). The apparatus also includes an ammonia target module (310) that is configured to determine an ammonia addition requirement (326). The apparatus additionally includes a reductant target module (330) that is configured to determine a reductant injection requirement (332) that includes an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement. The apparatus further includes a reductant modifier module (390) that is configured to determine a reductant modifier requirement (342). Also, the apparatus includes an ammonia oxidation (AMOX) conversion module (380) configured to determine a conversion capability (382) of an AMOX catalyst in exhaust receiving communication with the SCR catalyst.