Patent ID: 9038373
Filing Date: 2015-05-26
Classification: F01N,Y02T

Abstract:
1. A method, comprising: determining an amount of ammonia (NH3) present at a first exhaust gas conduit position that is downstream of a first selective catalytic reduction (SCR) catalyst and upstream of a second SCR catalyst; determining an actuator response function in response to at least one operating condition of the first SCR catalyst, wherein the actuator response function comprises a reductant injector response as a function of the amount of NH3, the actuator response function having a response discontinuity; determining a reductant injection amount in response to the amount of NH3 and the actuator response function; injecting an amount of reductant upstream of the first SCR catalyst in response to the reductant injection amount; and further comprising determining whether an NH3 fill-up override condition is present, and increasing the injected amount of reductant in response to the NH3 fill-up override condition.