Otto particle filter
A Otto particulate filter , short OPF also GPF (of English. Gasoline particulate filter ) is a device to reduce the exhaust gas of gasoline engines existing particles.
Structure and functionality
A gasoline particulate filter is primarily hardly any different from a diesel particulate filter . It is a closed particle filter, in which a highly heat-resistant porous cordierite - ceramic is used. The soot particles contained in the exhaust gas stick to the rough ceramic surface.
In contrast to diesel particulate filters, gasoline particle filters do not normally need active regeneration during operation, as the temperatures in the filter are so high due to the hotter exhaust gas that when the vehicle is decelerated with the injection switched off, the soot can burn with the air in the exhaust system.
Regulations
For vehicles with gasoline direct injection , limit values are specified for both the particle mass (PM) and the particle number (PN). In the Euro 6c emissions standard, these are 4.5 mg / km and 6 · 10 11 1 / km
Vehicles with intake manifold injection are not subject to the regulation, although there are vehicles that do not comply with the above-mentioned limit values.
application
In order to comply with these values, especially since the changeover to the new WLTP test cycle with greater accelerations and the consideration of emissions during practical driving (RDE), gasoline particulate filters are increasingly being used. The particle number (PN) is the more critical value.
Web links
- Christof Vieweg: Gasoline-powered vehicles also need a filter , Zeit-Online, February 25, 2017
- Ottopartikelfilter.de , accessed on July 11, 2018.