Optimized Diesel Particulate Filter System for Diesel Exhaust Aftertreatment

In the past twenty years, several works has been done on Diesel Particulate Filters (DPF), but the main obstacle for a car application was the regeneration in all operating conditions of the filter by combustion of particles that have been retained in the filter. The goal of this study was to address this main concern by developing a new system. The tests were performed on the most difficult test conditions: urban cycles only that mean low temperature. After screening of various regeneration solutions, electrical regeneration has been chosen but first test performed on cordierite filters showed some failures due to lack of thermal resistance of cordierite filter in some very severe conditions The second part of the experiment was done on an improved system consisting of electrical regeneration, silicon carbide filter, more accurate pressure sensors, and lower content of additives. These tests on urban cycle showed good control for process regeneration. We experienced various test conditions of speed and temperature that showed the cleaning of the filter can be accomplished. The resistance of the system in extremely severe regeneration conditions was clearly demonstrated. Fuel penalty and emission control were evaluated and finally, a complete system validation including on line soot loading control has been applied on a vehicle with several driving conditions