Nox Sensor Diagnostic For An Exhaust Aftertreatment System

• Main Authors: TONY JAMES HALL, CHRISTOPHER FERGUSON, BRIAN P. LIIMATTA, ANDREW W. OSBURN
• Format: Patent
• Language: Chinese; English
• Published: 06.07.2016
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; WEAPONS

A method for diagnosing NOx sensors in an exhaust aftertreatment system includes suspending reductant dosing in an exhaust aftertreatment system; purging a reductant deposit in a selective catalytic reduction (SCR) system of the exhaust aftertreatment system; adjusting at least one of an ignition timing and an engine speed for an engine to adjust an engine out nitrogen oxide (NOx) amount; receiving measured SCR inlet NOx data from a SCR inlet NOx sensor and measured SCR outlet NOx data from a SCR outlet NOx sensor; determining a phase shift between the measured SCR inlet and SCR outlet NOx data; applying the determined phase shift to the SCR outlet NOx data; and determining a diagnostic feature based on the SCR inlet NOx data and the phase shifted SCR outlet NOx data regarding a state of the SCR inlet and outlet NOx sensors. 本发明涉及用于排气后处理系统的NOx传感器诊断。用于诊断排气后处理系统中的NOx传感器的方法包括暂停排气后处理系统中的还原剂给料；清除排气后处理系统的选择性催化还原(SCR)系统中的还原剂沉积；调节发动机点火时机和发动机速度中的至少个以调节发动机排出的氮氧化物(NOx)量；接收来自SCR入口NOx传感器的测量的SCR入口NOx数据和来自SCR出口NOx传感器的测量的SCR