Patent ID: 8156733
Filing Date: 2012-04-17
Classification: F01N,Y02T

Abstract:
1. A method to operate an internal combustion engine equipped with an Electronic Control Unit (ECU) with memory, an exhaust system including, a Diesel Particulate Filter (DPF), a doser in said DPF actuated by commands from said ECU, a Diesel Oxidation Catalyst (DOC) upstream of a Selective Catalyst Reducer (SCR), and sensors at said DPF and said SCR electronically connected to said ECU to transmit data signals indicative of operating conditions at said DPF and said SCR, said method to heat said SCR to a temperature sufficient to operate efficiently, comprising; sensing temperature of said SCR at an inlet thereof; determining whether said temperature at said SCR inlet is at least a predetermined minimum temperature for a predetermined period of time to permit efficient operation of said SCR to reduce exhaust NOx; sensing temperature of said DPF at an outlet thereof; determining whether said temperature at said DPF outlet is at least a predetermined minimum temperature for a predetermined period of time to permit light off of said DPF; introducing heat into the exhaust stream sufficient to raise said SCR and said DPF to each of said predetermined minimum temperatures for each of said predetermined periods of time; and introducing fuel to said doser in said DPF after said DPF light off temperature is reached to increase operating efficiency of said SCR.