Nitrogen oxide trap purge controlling method for exhaust line in diesel engine of motor vehicle, involves detecting incomplete purge of nitrogen oxide trap situated on exhaust line of diesel engine

摘要

The method involves detecting incomplete purge of a nitrogen oxide trap situated on an exhaust line of a diesel engine. Quantity of reducers to be injected during subsequent purge of the trap for assuring complete purging of the trap, is estimated. A nitrogen oxide trap loading value measured by two nitrogen oxide sensors is compared with a nitrogen oxide trap loading value estimated by a loading model based on data provided by one of the sensors situated in upstream of the trap. Residual mass of nitrogen oxide is detected in the trap. An independent claim is also included for a device for controlling purge of a nitrogen oxide trap situated on an exhaust line of a diesel engine, comprising two sensors.