{
  "$type": "site.standard.document",
  "description": "The invention consists of a method and a device for controlling the regeneration of a NOx storage catalyst (1), which is arranged in the exhaust gas system (2) of an internal combustion engine (3) and can be operated in an absorption and a regeneration mode, wherein a change of operating parameters…",
  "path": "/patents/1111409",
  "publishedAt": "2001-07-25T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N3/0842",
    "VOLKSWAGEN AG [DE]"
  ],
  "textContent": "The invention consists of a method and a device for controlling the regeneration of a NOx storage catalyst (1), which is arranged in the exhaust gas system (2) of an internal combustion engine (3) and can be operated in an absorption and a regeneration mode, wherein a change of operating parameters of the internal combustion engine is made as a function of the operating state of the NOx storage catalyst. According to the invention, the NOx concentration in the exhaust gas downstream of the NOx storage catalyst is measured (4). To determine the operating state, in particular a damage of the NOx storage catalyst, at a transition of the NOx storage catalyst from the absorption mode to the regeneration mode, the values of characteristic features of a NOx desorption peak in the temporal progression of the NOx concentration are determined, compared with predetermined test patterns and a comparison result is formed, from which a catalyst state signal characterizing the operating state of the NOx catalyst is determined. The change in operating parameters includes the implementation of a regeneration measure as a function of the catalyst state signal in order to achieve optimal regeneration of the NOx storage catalyst. The device for controlling the regeneration of a NOx storage catalyst comprises an engine control unit (13) for detecting and influencing operating parameters of the internal combustion engine. Furthermore, a NOx control device is provided to which the measured values of a NOx sensor arranged downstream of the NOx storage catalyst for measuring the NOx concentration in the exhaust gas can be supplied and which comprises means for determining the values of characteristic features of a NOx desorption peak in the temporal progression of the NOx concentration at a transition of the NOx storage catalyst from the absorption mode to the regeneration mode, means for comparing the values of the characteristic features with predetermined test patterns and for forming a comparison result, as well as evaluation means for forming a catalyst state signal characterizing the operating state of the NOx storage catalyst as a function of the comparison result. According to the invention, the catalyst state signal can be supplied to the engine control unit for initiating a regeneration measure in order to achieve optimal regeneration of the NOx storage catalyst.",
  "title": "Method and apparatus for controlling the regeneration of an NOx-adsorption catalyst"
}