Process for controlling operation of nitrogen oxides storage catalyst in exhaust gas tract of a lean-burn internal combustion engine comprises operating engine with a lean fuel/air mixtures to determine degree of effective storage

摘要

Controlling the operation of a NOx storage catalyst comprises: (a) operating the engine in the storage phases with a lean fuel/air mixture; (b) operating the engine in the regenerating phases with a rich fuel/air mixture; (c) determining the degree of effective storage (H) in the storage phases; and (d) selecting the operating parameters in the storage and regenerating phases and the duration of these phases depending on the degree of effective storage. The NOx storage catalyst (3) arranged in the exhaust gas tract (4) of a lean-burn internal combustion (I.C.) engine (1).