The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 08, 2009
Filed:
Jan. 10, 2008
Aleksey Yezerets, Columbus, IN (US);
Sriram S. Popuri, Greenwood, IN (US);
Neal W. Currier, Columbus, IN (US);
William Shelbourne Epling, Waterloo, CA;
Paul James Millington, Reading, GB;
David Scott Lafyatis, Schaumburg, IL (US);
Aleksey Yezerets, Columbus, IN (US);
Sriram S. Popuri, Greenwood, IN (US);
Neal W. Currier, Columbus, IN (US);
William Shelbourne Epling, Waterloo, CA;
Paul James Millington, Reading, GB;
David Scott Lafyatis, Schaumburg, IL (US);
Cummins Inc., Columbus, IN (US);
Abstract
An OBD system that diagnoses on board the condition of NOx adsorber catalysts in diesel engines and that relies on existing mass-produced exhaust gas oxygen sensor, also known as lambda sensor, technology, and the following established phenomena. In a reducing environment, typical exhaust gas oxygen (lambda) sensors have different sensitivities to various reductants, with sensitivity decreasing in this order: H>CO>short-chain hydrocarbons>long-chain hydrocarbons. In the process of regeneration of the NOx adsorber catalyst, the original reductant may evolve into a different reductant species, e.g., via reactions such as a water-gas shift (WGS), a reforming, a partial oxidation, etc. This leads to a difference in exhaust gas oxygen sensor readings between the inlet to the catalyst and outlet from the catalyst. It has been observed in diesel engine testing that the ability of the NOx adsorber catalyst to perform such a reductant evolution is correlative to the catalyst's NOx reduction capability.