procedures to detect and maintain the operational capability of a nox speicherkatalysators

摘要

Exhaust temperature (Tvtr, Tnvk) is determined downstream of the nitrogen oxides (NOx) storage catalyst. From a temperature model, the monolith temperature, Tmon1 at the inlet of the NOx storage catalyst (17), is calculated. From this value and the model, monolith temperature Tmon2 is calculated at the outlet of the NOx storage catalyst. It is determined whether both temperatures lie in a given range (Tmin, Tmax) (the condition). In accordance with the determination, engine (10) operation is controlled, to ensure that the condition is fulfilled and maintained during continued operation.