On-Vehicle Fuel Cut Testing for Gasoline Particulate Filter Applications 2019-01-0968

With the introduction of a stringent particulate number (PN) limit and real driving emission (RDE) requirements, gasoline particulate filters (GPF) are widely adopted for gasoline engines in Europe and China. The filter collects soot and ash. Like in diesel applications, the collected soot will continuously burn under favorable exhaust conditions. However, at extreme operating conditions, there could be large amounts of soot build-up, which may induce a highly exothermal event, potentially melting the filter. Thus, it is important to understand what drives the over-heating in application, and develop counter measures. In this study, an on-vehicle fuel cut testing procedure was developed. The authors tested a gasoline direct injection (GDI) passenger car, and a multiple port injection (MPI) vehicle with different exhaust systems, with respect to the GPF location (close coupled vs under floor), and GPF coating (bare vs coated). Discussion on test variability and improvement methods are also included. Test results can be very well described with a simple model, which can be used to accelerate OEMs’ calibration efforts. Based on the observations the paper also discusses some typical OEM applications and recommendations on soot management. Key words: GPF, Fuel Cut, Soot Management, Modeling, Vehicle Testing