Patent ID: 8240129
Filing Date: 2012-08-14
Classification: F01N,F02D,Y02T

Abstract:
1. A method for diagnosing operation of a NOx adsorber catalyst configured to receive exhaust gas produced by an internal combustion engine, the method comprising: monitoring an operating temperature of the catalyst by monitoring a first temperature corresponding to a temperature of the exhaust gas entering the catalyst, monitoring a second temperature corresponding to a temperature of the exhaust gas exiting the catalyst, monitoring a third temperature corresponding to a temperature of the exhaust gas entering a turbocharger turbine positioned upstream of the catalyst, monitoring a fourth temperature corresponding to a temperature of the exhaust gas exiting the turbocharger turbine, monitoring an air flow corresponding to a mass flow rate of fresh air supplied to the engine by a turbocharger compressor, and estimating the operating temperature of the catalyst as function of the air flow and the first, second, third and fourth temperatures, when the operating temperature of the catalyst exceeds a catalyst desulfation temperature threshold, determining an oxygen storage capacity of the catalyst as a function of an oxygen concentration of the exhaust gas entering the catalyst and an oxygen concentration of the exhaust gas exiting the catalyst, and storing the oxygen storage capacity in a memory unit.