Method for operating an exhaust gas purification system of a motor vehicle combustion engine

US9644521B2 · kind B2 · utility

Assignee

• Daimler AG · DE

Inventors

• Rainer Hegemann · Ludwigsburg, DE
• Eugen Neuberger · North Duke Street, DE
• Markus Paule · Bad Marienberg, DE
• Norbert Waldbuesser · Stuttgart, DE

Key dates

• Filing date: Mar 15, 2014
• Grant date: May 9, 2017
• Expiry date: Mar 15, 2034

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

A method for operating an exhaust gas purification system of a motor vehicle internal combustion engine is disclosed. The system has an SCR catalyst where a reducing agent containing ammonia is metered into the exhaust gas at a predeterminable metering rate which is produced from a base value and an adaptation factor which corrects the base value. A test procedure checks and, if appropriate, adjusts the adaptation factor where a first nitrogen oxide value is compared with a second nitrogen oxide value of the exhaust gas, where the first and the second nitrogen oxide value are determined by the same nitrogen oxide sensor disposed downstream of the SCR catalyst. The first nitrogen oxide value is determined when the metering of the reducing agent is switched off and the second nitrogen oxide value is determined when the reducing agent is metered at a test metering rate which can be predetermined.