Abstract: A method of controlling an exhaust system for a diesel engine comprises providing an aftertreatment system comprising a first catalyst and a diesel exhaust fluid injection system, determining a preliminary dose of a diesel exhaust fluid of the diesel exhaust fluid injection system based on an incoming exhaust gas flow and an exhaust gas temperature, determining an NH3 factor based on incoming exhaust gas oxygen concentration and the incoming exhaust gas flow temperature, and determining a final dose of diesel exhaust fluid by multiplying the preliminary dose of diesel exhaust fluid by the NH3 factor.

Abstract: A method of controlling an exhaust system for a diesel engine comprises providing an aftertreatment system comprising a first catalyst and a diesel exhaust fluid injection system, determining a preliminary dose of a diesel exhaust fluid of the diesel exhaust fluid injection system based on an incoming exhaust gas flow and an exhaust gas temperature, determining an NH3 factor based on incoming exhaust gas oxygen concentration and the incoming exhaust gas flow temperature, and determining a final dose of diesel exhaust fluid by multiplying the preliminary dose of diesel exhaust fluid by the NH3 factor.

Abstract: Example methods and systems for treating exhaust from an internal combustion engine may generally determine a catalytic converter in an exhaust system is at least partially deactivated by detecting an elevated exhaust temperature and a lean-burn operating condition. In response, a deactivation level of the catalytic converter may be determined, which may be compared with a threshold deactivation level. A magnitude of a temporary rich-fuel operating condition as a response may be determined based upon the comparison. The catalytic converter may be reactivated with the temporary rich-fuel operating condition.

Abstract: Example methods and systems for treating exhaust from an internal combustion engine may generally determine a catalytic converter in an exhaust system is at least partially deactivated by detecting an elevated exhaust temperature and a lean-burn operating condition. In response, a deactivation level of the catalytic converter may be determined, which may be compared with a threshold deactivation level. A magnitude of a temporary rich-fuel operating condition as a response may be determined based upon the comparison. The catalytic converter may be reactivated with the temporary rich-fuel operating condition.

Abstract: An aftertreatment system includes a first pipe section in fluid communication with an exhaust manifold on an internal combustion engine. A first aftertreatment device includes a housing and a porous substrate having substrate walls defining a plurality of flow channels including first channels obstructed at a first end of the substrate and second channels obstructed at a second end of the substrate opposite the first end. The first and second channels are interleaved and internal pore surfaces in the porous substrate form a plurality of internal pores. A passive NOx adsorption catalyst is deposited on the substrate walls and internal pore surfaces such that the mean porosity of the porous substrate is not greater than a particulate matter secondary grain size. A second aftertreatment device having an inlet is in fluid communication with the outlet of the first aftertreatment device.

Abstract: A system and method for monitoring the temperature in a vehicle after-treatment system is provided. The system includes one or more temperature sensors positioned in the vehicle after-treatment system and an electronic control unit (ECU) configured by programming instructions encoded in computer readable media to execute a method. The method includes monitoring the temperature presented by the one or more temperature sensors, executing a lower oxygen combustion strategy for a slower exothermic reaction when the temperature exceeds a first threshold level, and deactivating the lower oxygen combustion strategy when the temperature drops below a second threshold level.

Abstract: A method for controlling a valve for directing an exhaust gas stream through an exhaust duct having an after treatment device and a bypass duct in an exhaust system of a vehicle is provided. The method includes receiving first sensor signals from a first sensor coupled downstream from the exhaust after treatment device, and processing the first sensor signals to determine a first temperature of an outlet exhaust gas stream. The method includes determining a bypass command based on whether the first temperature exceeds a first pre-defined threshold for the outlet exhaust gas stream. The method also includes outputting a control signal based on the determining of the bypass command to a valve coupled to the bypass duct and the exhaust pipe upstream of the after treatment device to move the valve between a first state and a second state.

Abstract: A method for monitoring particulate filter disposed in an exhaust aftertreatment system of an internal combustion engine includes determining, via a differential pressure sensor, a pressure differential across the particulate filter, and determining an initial parameter associated with soot loading on the particulate filter based upon the pressure differential. A first adjustment to the soot loading is determined based upon a passive regeneration effect, a second adjustment to the soot loading is determined based upon an off-engine temperature effect, and a third adjustment to the soot loading is determined based upon occurrence of an interrupted regeneration event. A final parameter associated with soot loading on the particulate filter is determined based upon the initial parameter and the first, second and third adjustments.

Abstract: A system and method for monitoring the temperature in a vehicle after-treatment system is provided. The system includes one or more temperature sensors positioned in the vehicle after-treatment system and an electronic control unit (ECU) configured by programming instructions encoded in computer readable media to execute a method. The method includes monitoring the temperature presented by the one or more temperature sensors, executing a lower oxygen combustion strategy for a slower exothermic reaction when the temperature exceeds a first threshold level, and deactivating the lower oxygen combustion strategy when the temperature drops below a second threshold level.

Abstract: Methods for mitigating over-temperature during an exhaust gas system particulate filter device regeneration are provided. The exhaust gas system can include an exhaust gas stream supplied by an exhaust gas source to a particulate filter device through an exhaust gas conduit. The methods can include detecting an over-temperature during a particulate filter regeneration, initiating one or more first mitigation strategies, and shutting down the exhaust gas source. The one or more first mitigation strategies can include inhibiting the particulate filter device regeneration, altering the exhaust gas source operating parameters, and activating a cooling fan. The exhaust gas source can include an internal combustion engine configured to power a vehicle, and the operating parameters can be altered by a torque limiter.

Abstract: A method for controlling a valve for directing an exhaust gas stream through an exhaust duct having an after treatment device and a bypass duct in an exhaust system of a vehicle is provided. The method includes receiving first sensor signals from a first sensor coupled downstream from the exhaust after treatment device, and processing the first sensor signals to determine a first temperature of an outlet exhaust gas stream. The method includes determining a bypass command based on whether the first temperature exceeds a first pre-defined threshold for the outlet exhaust gas stream. The method also includes outputting a control signal based on the determining of the bypass command to a valve coupled to the bypass duct and the exhaust pipe upstream of the after treatment device to move the valve between a first state and a second state.

Abstract: An aftertreatment system for an internal combustion engine includes a diesel cold start catalyst member, a lean NOx trap (LNT) member arranged directly adjacent to and downstream of the diesel cold start catalyst, and a selective catalyst reduction (SCR) member arranged downstream of the LNT. The diesel cold start catalyst is operable to reduce NOx emissions at operating temperatures below 200° C. and the LNT and SCR system are operable to reduce NOx emissions at operating temperatures above 200° C.

Abstract: A method for monitoring particulate filter disposed in an exhaust aftertreatment system of an internal combustion engine includes determining, via a differential pressure sensor, a pressure differential across the particulate filter, and determining an initial parameter associated with soot loading on the particulate filter based upon the pressure differential. A first adjustment to the soot loading is determined based upon a passive regeneration effect, a second adjustment to the soot loading is determined based upon an off-engine temperature effect, and a third adjustment to the soot loading is determined based upon occurrence of an interrupted regeneration event. A final parameter associated with soot loading on the particulate filter is determined based upon the initial parameter and the first, second and third adjustments.

Abstract: Methods for mitigating over-temperature during an exhaust gas system particulate filter device regeneration are provided. The exhaust gas system can include an exhaust gas stream supplied by an exhaust gas source to a particulate filter device through an exhaust gas conduit. The methods can include detecting an over-temperature during a particulate filter regeneration, initiating one or more first mitigation strategies, and shutting down the exhaust gas source. The one or more first mitigation strategies can include inhibiting the particulate filter device regeneration, altering the exhaust gas source operating parameters, and activating a cooling fan. The exhaust gas source can include an internal combustion engine configured to power a vehicle, and the operating parameters can be altered by a torque limiter.