Patent ID: 10322373

Abstract:
Provided is a method for controlling an exhaust gas treatment system, wherein the system includes an exhaust gas stream supplied by an exhaust gas source to a selective catalytic reduction (SCR) device and a particulate filter device. The method comprises detecting a threshold level of reductant deposits proximate the SCR device, and initiating a selective catalytic reduction device service in response thereto. A threshold level of reductant deposits is detected using a reductant deposit model comprising determining an actual SCR NOx conversion using measured process variables; and comparing the actual SCR NOx conversion to a calibrated NOx conversion value. The calibrated NOx conversion value is determined using exhaust gas flow and system temperature values which substantially correspond to the process variables under which the actual SCR NOx conversion was determined. The device service can include increasing the exhaust gas temperature or initiating an active regeneration of the particulate filter device.