Method and system for controlling oxygen levels in exhaust gases emitted from an i.c. engine for particulate filter regeneration

摘要

A method and system for controlling oxygen levels in exhaust gases emitted from an i.c. engine adjusts the amount of cooled EGR and non-cooled EGR to allow the temperature of the exhaust gases to be controlled in order to achieve a desired temperature for regeneration of a particulate filter. The exhaust gas recirculation may be directed and controlled through an EGR cooler, an air cooler, as well as a cooler bypass to achieve the desired exhaust gas temperature. Also disclosed is a method which includes controlling the oxygen levels as a function of the soot burn rate of the filter, and a method which includes monitoring these rates during regeneration to prevent an uncontrolled soot burn rate condition.