OPTIMIZATION OF AMMONIA DOSING DURING REGENERATION

摘要

A method for managing ammonia dosing during a regeneration event for a nitrogen oxide particulate filter (NPF) includes a selective catalytic reduction system and a particulate filter. Embodiments include utilizing monitored pressure changes across the NPF to predict the soot load and when the soot load will reach a level that triggers a regeneration event. The predicted timing of the regeneration event is used to utilize ammonia absorbed on the NPF and adjust the amount or rate of dosing ammonia to manage ammonia levels in the NPF during the regeneration event. Prior to the regeneration event, the amount of dosing ammonia may be reduced so that ammonia released from the NPF is utilized in converting nitrogen oxides to nitrogen gas and water. After the released ammonia has been utilized, the amount of dosing ammonia may be increased so that the conversion of the nitrogen oxides continues.