Exhaust aftertreatement system with catalytic deactivation monitoring

摘要

A system includes a controller configured to determine if a combustion engine is operating under a desired rich fuel condition. The controller is also configured, if the combustion engine is operating under the desired rich fuel condition, to monitor a catalytic activity within an ASC assembly that converts NH3 within treated exhaust gases from the combustion engine into N2 to determine whether the catalytic activity has been deactivated in the ASC assembly.

主权项

1. A system, comprising:
an exhaust aftertreatment system configured to treat emissions from a combustion engine, wherein the exhaust aftertreatment system comprises:
a three-way catalyst (TWC) assembly having a first inlet;an ammonia slip catalyst (ASC) assembly configured to receive treated exhaust gases from the TWC assembly and to convert ammonia (NH3) within the treated exhaust gases into nitrogen (N2), wherein the ASC assembly has a second inlet and an outlet;at least one oxygen (O2) sensor disposed upstream of the first inlet of the TWC assembly and configured to determine a concentration of O2 in exhaust gases generated by the combustion engine;at least one nitrogen oxides (NOx) sensor disposed downstream of the outlet of the ASC assembly and configured to measure a concentration of NOx in the treated exhaust gases exiting the outlet of the ASC assembly; anda controller comprising a memory encoding one or more processor-executable routines and a processor configured to access and execute the one or more routines encoded by the memory, wherein the routines, when executed cause the processor to receive a first signal from the at least one NOx sensor representative of the concentration of NOx in the treated exhaust gases exiting the outlet of the ASC assembly and a second signal from the at least one O2 sensor representative of the concentration of O2 in the exhaust gases generated by the combustion engine, and to determine whether the catalytic activity has been deactivated in the ASC assembly based at least in part on the received first and second signals or by determining if the concentration of NOx in the treated exhaust gases exiting the ASC assembly is greater than a NOx threshold value, and wherein the controller is configured to determine whether corrective action is needed to clean the ASC assembly to reactivate the catalytic activity if it is determined that the catalytic activity in the ASC assembly has been deactivated, and to cause a user perceptible signal to be provided indicating the need for corrective action.