Journal Article
Degradation of Nonmethane Hydrocarbon Oxidation Efficiency of a Catalyzed Diesel Particulate Filter during Aging
2011-04-12
2011-01-1308
Upcoming 2013 on-board diagnostic (OBD) requirements mandate that catalyzed diesel particulate filter (CDPF) nonmethane hydrocarbon (NMHC) oxidation efficiency degradation be monitored as the filter ages. The malfunction indicator lamp (MIL) is to light when exhaust NMHC levels are greater than two times the legal limit or when the CDPF has no detectable amount of NMHC conversion capability. In this study, a CDPF was thermoelectrically aged at 650°C from the degreened (near-new) to end of useful life (EUL) stage. CDPF total hydrocarbon (THC) oxidation efficiency was measured periodically using a suite of steady-state speed and load conditions ("snapshot test"). The snapshot test was performed after every seven hours of filter aging. Snapshot test data of steady-state THC oxidation efficiency change across the filter at the chosen operating conditions shows no discernible, consistent degradation as the filter is aged.