Abstract: Various embodiments of an apparatus, system, and method are disclosed for controlling NOx conversion in a selective catalytic reduction (SCR) system. According to one representative embodiment, an apparatus includes a duty cycle factor module and a NOx conversion mode selection module. The duty cycle factor module is configured to determine a duty cycle factor of an internal combustion engine where the duty cycle factor represents predicted driving conditions of a vehicle in which the internal combustion engine is housed. The NOx conversion mode selection module is configured to command NOx conversion in the SCR system according to a first NOx conversion mode if the duty cycle factor is within a duty cycle factor range and according to a second NOx conversion mode if the duty cycle factor is not within the duty cycle factor range.

Abstract: One embodiment is a method including determining whether an ammonia storage device has a stored quantity of ammonia, predicting an impending ammonia release from the ammonia storage device, determining a NOx increase amount in response to the impending ammonia release, and increasing an amount of NOx provided by an engine based on the NOx increase amount. In certain embodiments, determining the NOx increase amount in response to the impending ammonia release comprises determining a NO increase schedule based on the stored quantity of ammonia. In certain embodiments, the NOx increase schedule comprises a specified NOx increase time period, and in certain further embodiments, the method further includes decrementing the specified NOx increase time period based on an estimated catalyst degradation value.

Abstract: Described herein are various embodiments of an apparatus, a system, and a methods for reducing NOx emissions using ammonia storage on an SCR catalyst. For example, according to one embodiment, an apparatus for controlling an SCR system of an internal combustion engine system includes an ammonia storage module and a reductant dosing module. The ammonia storage module determines an ammonia storage surface coverage on an SCR catalyst of the SCR system and an ammonia compensation value based on one of an excess ammonia flow rate entering the SCR catalyst and an excess NOx flow rate entering the SCR catalyst. The reductant dosing module that generates a reductant dosing command based on the ammonia compensation value.

Abstract: Various embodiments of an apparatus, system, and method are disclosed for manipulating the properties of engine exhaust at least partially through the engine's control system to increase the efficiency and performance of the exhaust aftertreatment system. According to one representative embodiment, an engine system properties controller includes an exhaust aftertreatment system module, a powertrain module, and a combustion module. The exhaust aftertreatment system module is configured to generate an exhaust conditions vector request. The powertrain module is configured to receive the exhaust conditions vector request from the exhaust aftertreatment system module and generate at least one engine operating condition target based on the exhaust conditions vector request. The combustion module is configured to receive the at least one engine operating condition target and generate at least one engine controls command based on the at least one engine operating condition target.

Abstract: An apparatus, system, and method are disclosed for enhancing the efficiency of an exhaust aftertreatment application. The method may include determining the current operating conditions of the application, the optimal operating conditions of a target component, and the performance criteria of a conditioning component relative to the optimal operating conditions. The method may include determining an optimal fraction of an exhaust flow to pass through the conditioning component to achieve the optimal operating conditions of the target component. The method may further include manipulating a bypass valve position based on the optimal fraction of exhaust flow to pass through the conditioning component. The target component may be a selective catalyst reduction (SCR) component that operates optimally at a designed NO2/NOx mole ratio. The conditioning component may be a diesel oxidation catalyst (DOC) that affects the NO2/NOx mole ratio.

Abstract: Various embodiments of an apparatus, system, and method are disclosed for controlling NOx conversion in a selective catalytic reduction (SCR) system. According to one representative embodiment, an apparatus includes a duty cycle factor module and a NOx conversion mode selection module. The duty cycle factor module is configured to determine a duty cycle factor of an internal combustion engine where the duty cycle factor represents predicted driving conditions of a vehicle in which the internal combustion engine is housed. The NOx conversion mode selection module is configured to command NOx conversion in the SCR system according to a first NOx conversion mode if the duty cycle factor is within a duty cycle factor range and according to a second NOx conversion mode if the duty cycle factor is not within the duty cycle factor range.

Abstract: An apparatus, system, and method are disclosed for enhancing the efficiency of an exhaust aftertreatment application. The method may include determining the current operating conditions of the application, the optimal operating conditions of a target component, and the performance criteria of a conditioning component relative to the optimal operating conditions. The method may include determining an optimal fraction of an exhaust flow to pass through the conditioning component to achieve the optimal operating conditions of the target component. The method may further include manipulating a bypass valve position based on the optimal fraction of exhaust flow to pass through the conditioning component. The target component may be a selective catalyst reduction (SCR) component that operates optimally at a designed NO2/NOx mole ratio. The conditioning component may be a diesel oxidation catalyst (DOC) that affects the NO2/NOx mole ratio.