Method and arrangement for evaluating the operability of a catalytic converter

Abstract

Abstract The invention is directed to a method for evaluating the operability of a catalytic converter operated in the exhaust-gas channel of an internal combustion engine. The invention utilizes the recognition that the conversion-begin temperature of the catalytic converter is that much higher the more the catalytic converter has deteriorated. In improved embodiments, the realization is utilized that the more a catalytic converter has deteriorated, the less heat is converted by combusting oxidizable exhaust gas components per unit of time. In a first embodiment of the method, a check is made as to when a catalytic converter starts converting and then evaluating the converter as being operable when the determined temperature is less than a comparison temperature. A second embodiment provides that the catalytic converter is operated at precisely pregiven operating conditions and a check is made as to how long is required until the converter begins to convert. The catalytic converter is operable if the measured time span is less than a comparison time span. In a third embodiment, the temperature of the catalytic converter is estimated with a model. As soon as the estimated temperature reaches a comparison temperature, a check is made as to whether the catalytic converter has exceeded this temperature. If this is the case, then the catalytic converter is evaluated as being operable. Arrangements according to the invention include devices for carrying out the steps required for the above-mentioned methods.

Inventors

• 👤 Klaus Ries-Mueller

Bibliographic Details