Method and model for modeling a discharge phase of a nitrous oxide storage catalytic converter

摘要

The invention relates to a method and a model for modeling a discharge phase of a nitrogen oxide (NOx)-storage catalytic converter (12') of an internal combustion engine (1), especially of a motor vehicle. The NOx-storage catalytic converter (12') is subdivided into an oxygen (O2)-store and a nitrogen oxide (NOx)-store and a reducing agent mass flow (msrg) is determined which charges the O2-store and the NOx-store. In order to model a discharge phase of the NOx-storage catalytic converter (12') reliably and precisely and with the least possible complexity, the suggestion is made that the O2-store is modeled via a first integrator for oxygen (O2) and the NOx-store via a second integrator for nitrogen oxide (NOx) and the first integrator and the second integrator are charged proportionally with the reducing agent mass flow (msrg) in accordance with an apportioning factor. The apportioning factor (fatmsre) is determined in dependence upon the O2-store content (mno2sp) and of the NOx-store content (mnosp) of the NOx-storage catalytic converter (12').