Impacts of Drive Cycle and Ambient Temperature on Modelled Gasoline Particulate Filter Soot Accumulation and Regeneration

Gasoline particulate filters (GPF) are used as an efficient solution to reduce particulate matter (PM) emissions on gasoline vehicles. GPFs are ceramic wall-flow filters and are normally located downstream of conventional three-way catalysts (TWC) [1]. The study in this paper is intended to evaluate the impact of drive cycle and ambient temperature on modelled GPF soot accumulation and regeneration. The test data were obtained through real road testing in Chinese cities including Nanjing, Hainan and Harbin. Five 2.0 L gasoline turbo direct-injection (GTDI) prototype vehicles from several China Stage 6 applications were employed for the road tests. The results of the testing indicated that a drive cycle with low engine speed and engine load, like a typical city road in rush hour traffic in Nanjing, had a low probability of generating high GPF temperatures (> 600 °C) and sufficient oxygen to regenerate the GPF. However, the soot accumulation model performed as expected [2] and the soot regeneration model demonstrated sufficient opportunity to oxidize soot prior to excessive soot accumulation, even under the limited city drive cycle conditions. Ambient temperatures during cold engine starts played a significant role in the amount of modeled soot being generated during any given drive cycle. Considerably more soot was generated during cold starts at low ambient conditions (< 0 °C) due to the increase in fuel mass and the use and duration of compression injection to aid in catalyst heating.