RETRAITEMENT DU GAZ D'ECHAPPEMENT D'UN MOTEUR DIESEL A COMBUSTION INTERNE COMPORTANT UN FILTRE A PARTICULES

摘要

The temperature of recycled exhaust gas is regulated by a cooler (11) placed in a recirculation line (9) as a function of the operating state of the engine (1). The recirculation line has a first line (10) with a cooler and a second parallel line (12). Valves (13, 14) control the fraction of recycled exhaust gas passing down each line to give the remixed gas a predetermined temperature. To regenerate the particle filter (6), the recycled exhaust gas is carried with a reduced cooling power or even uncooled from the combustion chamber. A complementary injection is carried out in the combustion chamber to increase the temperature of the particle filter. The exhaust gas recirculation is increased in a direction up to the limit of the soot to continue to increase the temperature of the particle filter. The air side is throttled to continue to increase the temperature of the particle filter. The exhaust gas recirculation for increased load is reduced or even suppressed in the case where sufficiently hot exhaust gas reaches the particle filter by operating at increased load. The exhaust gas is recycled in the uncooled state in the zone of the engine's characteristic diagram between a braking regime and a mean regime of 2500/minute and a load of between 0 and 2.5 bars of mean pressure effective up to at least 50%, preferably up to at least 70%, knowing that in all the other zones of the characteristic diagram the exhaust gas is cooled to at least 50%, preferably up to 70% of the characteristic diagram. The exhaust gas recirculation and its temperature control are controlled by characteristic diagram. A catalyst can be placed upstream of the particle filter.