Integrated engine and exhaust after treatment system and method of operating same

• Main Authors: Kesse, Mary L, Scrivner, Wade D, Jayachandran, Amit, Zhu, Liangtao
• Format: Patent
• Language: English
• Published: 03.07.2012

An engine system includes an integrated engine and aftertreatment control system via an electronic aftertreatment controller that is in communication with the electronic engine controller. An aftertreatment control algorithm is operable to generate an exhaust control signal and a reductant dosing control signal. The dosing control signal is used to control a flow rate of a reductant (e.g. urea) injection rate into the exhaust system for facilitating a reduction reaction with NOx in the exhaust flow at a suitable downstream catalyst location. The exhaust control signal is communicated to the electronic engine controller, which responds by altering engine operation to change some aspect of the engine exhaust. In one specific example, an ammonia slip event precondition is detected by the electronic aftertreatment controller, and an exhaust control signal in the form of an increase NOx request is communicated to the engine controller, which responds by altering engine operation to increase NOx output in the hopes of preempting the expected ammonia slip event prior to its actual occurrence to maintain undesirable emissions low at the tailpipe.