Numerical Study on Filtration of Soot Particulates in Gasoline Exhaust Gas by SiC Fiber Filter

摘要

As for gasoline vehicles, the particulate matter (PM) emissions from traditional port fuel injection (PFI) engines are pretty low. Recently, the gasoline direct injection (GDI) vehicles have been gaining market share globally due to better fuel efficiency, especially in the European countries. A drawback associated with GDI engines is considerably higher PM emissions compared with PFI engines. The soot in gasoline exhaust gas would contribute to urban air pollution, which is deeply related with adverse health effects. For the reduction of PM emission in Europe, a new regulation known as EURO VI has been set recently. Then, we need to trap soot particles in exhaust gas from gasoline automobiles as well as diesel automobiles. However, the gasoline soot would be much smaller than the diesel soot. Also, the gasoline exhaust gas temperature is much higher. Then, we need gasoline particulate filter (GPF) which needs to have better thermal durability. In this study, as a potential GPF, an SiC fiber filter was numerically examined. The effect of the fiber diameter on the filtration was revealed. Results show that, when the filter of the larger fiber diameter is placed more upstream, the deposition of soot particles widely occurs inside the filter, resulting in the lower pressure drop.