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System and method for controlling ammonia levels in a selective catalytic reduction catalyst using a nitrogen oxide sensor

United States Patent

July 25, 2017
View the Complete Patent at the US Patent & Trademark Office
A system according to the principles of the present disclosure includes an air/fuel ratio determination module and an emission level determination module. The air/fuel ratio determination module determines an air/fuel ratio based on input from an air/fuel ratio sensor positioned downstream from a three-way catalyst that is positioned upstream from a selective catalytic reduction (SCR) catalyst. The emission level determination module selects one of a predetermined value and an input based on the air/fuel ratio. The input is received from a nitrogen oxide sensor positioned downstream from the three-way catalyst. The emission level determination module determines an ammonia level based on the one of the predetermined value and the input received from the nitrogen oxide sensor.
Sun; Min (Troy, MI), Perry; Kevin L. (Fraser, MI), Dibble; Donovan L. (Utica, MI), Kim; Chang H. (Rochester, MI), Furness; Mary Beth (Ann Arbor, MI)
GM Global Technology Operations LLC (Detroit, MI)
13/ 192,859
July 28, 2011
STATEMENT OF GOVERNMENT RIGHTS This invention was produced pursuant to United States Government Program No. DE-EE0003379 with the Department of Energy (DoE). The U.S. Government has certain rights in this invention.