Method for monitoring components in an exhaust after treatment system, an exhaust after treatment system, and a controller for an exhaust after treatment system

摘要

Components in an exhaust after treatment system (EATS) for a diesel engine are monitored by measuring heat released (QDOC) across a diesel oxidation catalyst (DOC) and heat released (QEATS) across the DOC and a diesel particulate fi lter (DPF) during an A Hi injection event, by calculating heat input from AHI fuel (QAHI) during performance of the AH I injection event with a fully functioning AHI nozzle, and by measuring NOX conversion efficiency (nSCR) from NOX to N2 by a selective catalytic reduction system (SCR) at a condition where a SCR is sensitive to feeding gas compositions while AHI is not in use, Malfunctioning components are identified using these measurements and calculations.