Abstract:
A system operates to bypass one or more exhaust purifying devices during deceleration fuel cut-off (DFCO) events in order to avoid hydrocarbon purging. The system includes an internal combustion engine and exhaust purifying system including a first purifying device and a second purifying device. An exhaust gas sensor monitors an exhaust gas feedstream. A diverter valve is disposed to manage the exhaust gas feedstream and fluidly coupled to an exhaust diversion pipe. A controller detects operation of the engine in a DFCO state and monitors the exhaust gas feedstream via the exhaust sensor. The diverter valve is controlled to divert the exhaust gas feedstream away from at least one of the first and second purifying devices during the DFCO event when the exhaust gas feedstream has an air/fuel ratio that is greater than a threshold air/fuel ratio.
Abstract:
A system operates to bypass one or more exhaust purifying devices during deceleration fuel cut-off (DFCO) events in order to avoid hydrocarbon purging. The system includes an internal combustion engine and exhaust purifying system including a first purifying device and a second purifying device. An exhaust gas sensor monitors an exhaust gas feedstream. A diverter valve is disposed to manage the exhaust gas feedstream and fluidly coupled to an exhaust diversion pipe. A controller detects operation of the engine in a DFCO state and monitors the exhaust gas feedstream via the exhaust sensor. The diverter valve is controlled to divert the exhaust gas feedstream away from at least one of the first and second purifying devices during the DFCO event when the exhaust gas feedstream has an air/fuel ratio that is greater than a threshold air/fuel ratio.
Abstract:
A monitoring system for a single can oxidation catalyst (OC)/particulate filter (PF) member includes a controller including a first temperature sensor input configured to receive a first exhaust temperature upstream of an OC portion of the single can OC/PF member, a second temperature sensor input configured to receive a second exhaust temperature downstream of the first temperature. The controller is configured and disposed to calculate an exothermic capacity of the OC portion and determine washcoat deterioration of a PF portion of the single can OC/PF member based on the exothermic capacity of the OC portion.
Abstract:
A method is disclosed for controlling regeneration in a diesel engine after-treatment system having a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF). The method includes injecting an amount of fuel into an exhaust gas flow upstream of the DOC to superheat the gas flow and assessing a rate of the warm-up of the DOC. The method also includes determining, in response to the assessed rate of the warm-up of the DOC, an amount of catalyst substance available in the DOC for catalyzing the exhaust gas flow. The method additionally includes reducing the amount of fuel injected into the DOC such that the determined available amount of catalyst substance is utilized in the DOC for catalyzing the exhaust gas flow and a predetermined amount of fuel is permitted to slip through the DOC to maintain regeneration temperature in the DPF. A system and a vehicle are also disclosed.
Abstract:
A monitoring system for a single can oxidation catalyst (OC)/particulate filter (PF) member includes a controller including a first temperature sensor input configured to receive a first exhaust temperature upstream of an OC portion of the single can OC/PF member, a second temperature sensor input configured to receive a second exhaust temperature downstream of the first temperature. The controller is configured and disposed to calculate an exothermic capacity of the OC portion and determine washcoat deterioration of a PF portion of the single can OC/PF member based on the exothermic capacity of the OC portion.