Method for monitoring the catalytic activity of a catalytic converter in the exhaust gas system of an internal combustion engine

US5339628A · kind A · utility

Assignee

• EMITEC Gesellschaft fuer Emissionstechnologie mbH · DE

Inventors

• Wolfgang Maus · Bensberg, DE
• Helmut Swars · Bensberg, DE
• Rolf Brück · Bensberg, DE

Key dates

• Filing date: Mar 1, 1993
• Grant date: Aug 23, 1994
• Expiry date: Mar 1, 2013

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine includes measuring a temperature at least at two temperature measuring sensors and periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system. According to one method, the sensors are spaced apart in flow direction in or near the catalytic converter, the temperature measuring variable is averaged over a sufficiently long period of engine operation to average out special strains and form a mean temperature value, catalytic activity is ascertained by comparing the mean temperature value with a predetermined limit value, and a report is issued if the mean temperature value does not correspond to the limit value. According to another method, the sensors are associated with the catalytic converter, further measuring variables characterizing an applicable operating state of the engine are determined, a temperature limit value is determined from the further measuring variables, catalytic activity is determined by comparing the …