Abstract: A reductant dosing system includes an injector, a fixed displacement pump in fluid communication with the injector, a reductant source in fluid communication with the fixed displacement pump, a pressure sensor assembly that detects a pressure of a reductant and stores a calibration value, and a controller communicatively coupled to the fixed displacement pump and the pressure sensor assembly. The controller receives data that includes the detected pressure of the reductant and the calibration value. The controller, in response to the calibration value being within a predetermined calibration value range, calculates a flow rate of the fixed displacement pump based on at least the detected pressure and the calibration value, and, in response to the calibration value being outside the predetermined calibration value range, calculates the flow rate of the fixed displacement pump based on at least the detected pressure and a pre-determined calibration value different from the calibration value.

Abstract: A reductant dosing system includes: an injector; a fixed displacement pump in fluid communication with the injector; a reductant source in fluid communication with the fixed displacement pump; a pressure sensor assembly configured to detect a pressure of reductant in the reductant dosing system; and a controller communicatively coupled to the fixed displacement pump and to the pressure sensor assembly, wherein the controller is configured to calculate a flow rate of the fixed displacement pump based on at least a calibration value determined based on data received from the pressure sensor assembly.

Abstract: A header assembly for an aftertreatment system includes: a header including: a suction port, and a return port; a first splitting device configured to receive a first flow of reductant from the suction port and to split the first flow into a first inlet flow and a second inlet flow; a second splitting device configured to receive a first outlet flow and a second outlet flow and to provide a second flow to the return port of the header; a first inlet line configured to direct the first inlet flow to a first dosing module; a second inlet line configured to direct the second outlet flow to a second dosing module; a first outlet line configured to direct the first outlet flow to the second splitting device; and a second outlet line configured to direct the second outlet flow to the second splitting device.

Abstract: An aftertreatment system includes a first dosing module, a second dosing module, and a reductant tank assembly. The reductant tank assembly includes a reductant tank, a header coupled to the reductant tank, and a first splitting device that splits a first flow from the header into a first inlet flow and a second inlet flow. A first inlet line and a second inlet line direct the first inlet flow and the second inlet flow to the first dosing module and the second dosing module. A first outlet line and a second outlet line direct a first outlet flow and a second outlet flow from the first dosing module and the second dosing module to a second splitting device. The second splitting device merges the first outlet flow and the second outlet flow into a second flow and provides the second flow to the header.

Abstract: An aftertreatment system includes a first dosing module, a second dosing module, and a reductant tank assembly. The reductant tank assembly includes a reductant tank, a header coupled to the reductant tank, and a first splitting device that splits a first flow from the header into a first inlet flow and a second inlet flow. A first inlet line and a second inlet line direct the first inlet flow and the second inlet flow to the first dosing module and the second dosing module. A first outlet line and a second outlet line direct a first outlet flow and a second outlet flow from the first dosing module and the second dosing module to a second splitting device. The second splitting device merges the first outlet flow and the second outlet flow into a second flow and provides the second flow to the header.

Abstract: An aftertreatment system comprises a SCR system, a reductant injector operatively coupled to the SCR system, and a reductant insertion assembly operatively coupled to the reductant injector. The reductant insertion assembly comprises a pump configured to pump the reductant through the reductant injector. A controller is operatively coupled to the reductant insertion assembly and configured to receive predetermined calibration values of the pump corresponding to delivery of a reductant by the pump through a calibration injector. The controller determines a desired flow rate value of the reductant into the SCR system. The controller determines an insertion time of the reductant injector for delivering the reductant through the reductant injector based on the desired flow rate value, a pump operating parameter value of the pump and the predetermined calibration values, and activates the reductant injector for the insertion time.

Abstract: A reductant dosing system includes: an injector; a fixed displacement pump in fluid communication with the injector; a reductant source in fluid communication with the fixed displacement pump; a pressure sensor assembly configured to detect a pressure of reductant in the reductant dosing system; and a controller communicatively coupled to the fixed displacement pump and to the pressure sensor assembly, wherein the controller is configured to calculate a flow rate of the fixed displacement pump based on at least a calibration value determined based on data received from the pressure sensor assembly.

Abstract: An aftertreatment system comprises a SCR system, a reductant injector operatively coupled to the SCR system, and a reductant insertion assembly operatively coupled to the reductant injector. The reductant insertion assembly comprises a pump configured to pump the reductant through the reductant injector. A controller is operatively coupled to the reductant insertion assembly and configured to receive predetermined calibration values of the pump corresponding to delivery of a reductant by the pump through a calibration injector. The controller determines a desired flow rate value of the reductant into the SCR system. The controller determines an insertion time of the reductant injector for delivering the reductant through the reductant injector based on the desired flow rate value, a pump operating parameter value of the pump and the predetermined calibration values, and activates the reductant injector for the insertion time.

Abstract: A controller configured to be operatively coupled to a reductant insertion assembly comprising a first pump for inserting a reductant into a selective catalytic reduction system, is programmed to set an insertion interval timer for the first insertion interval in response to receiving a first insertion command. The controller starts the insertion interval timer, records an elapsed time period from the start of the insertion interval timer, and activates the first pump when the timer starts. The controller receives a second insertion command comprising information for activating the first pump for a second duty cycle for second insertion intervals different than the first insertion interval. If the second insertion interval is smaller than the recorded elapsed time period, the insertion interval timer is set for the second insertion interval, the insertion interval timer is started, and if not already activated, the first pump is activated for the second duty cycle.

Abstract: A controller configured to be operatively coupled to a reductant insertion assembly comprising a first pump for inserting a reductant into a selective catalytic reduction system, is programmed to set an insertion interval timer for the first insertion interval in response to receiving a firs insertion command. The controller starts the insertion interval timer, records an elapsed time period from the start of the insertion interval timer, and activates the first pump when the timer starts. The controller receives a second insertion command comprising information for activating the first pump for a second duty cycle for second insertion intervals different than the first insertion interval. If the second insertion interval is smaller than the recorded elapsed time period, the insertion interval timer is set for the second insertion interval, the insertion interval timer is started, and if not already activated, the first pump is activated for the second duty cycle.

Abstract: An assembly for reductant dosing error correction in an exhaust aftertreatment system includes an injector comprising a reductant insertion conduit; a pump configured to advance a quantity of dosed fluid reductant from a reductant source; a reductant source outlet defined by the reductant source and configured to release the quantity of dosed fluid reductant into the reductant insertion conduit; a pressurized reductant receiving chamber defining a pressurized reductant receiver inlet; a reductant insertion pressure sensor; and a doser comprising a controller. The controller of the doser is configured to, based on a first actual pressure of the reductant, calculate a second target flow rate for a second injection event subsequent to a first injection event and control a quantity of dosed fluid reductant released during the second injection event based on the second target flow rate.

Abstract: A controller includes a switching delay circuit structured to determine an open delay time and a close delay time for a reductant injector, each based on battery voltage and reductant injector coil temperature. A dosing circuit is structured to determine an open time that the armature pin must be in the fully open position so as to cause the injector to inject a first quantity of reductant. An actuation time is determined based on each of the open time, the open delay time, and the close delay time. The actuation time relates to a time that the coil must be energized so as to cause the injector to inject the first quantity of reductant. A switching command signal is transmitted to the injector to energize the coil for the calculated actuation time so as to cause the injector to inject the first quantity of reductant into an exhaust gas stream.

Abstract: An assembly for reductant dosing error correction in an exhaust aftertreatment system includes an injector comprising a reductant insertion conduit; a pump configured to advance a quantity of dosed fluid reductant from a reductant source; a reductant source outlet defined by the reductant source and configured to release the quantity of dosed fluid reductant into the reductant insertion conduit; a pressurized reductant receiving chamber defining a pressurized reductant receiver inlet; a reductant insertion pressure sensor; and a doser comprising a controller. The controller of the doser is configured to, based on a first actual pressure of the reductant, calculate a second target flow rate for a second injection event subsequent to a first injection event and control a quantity of dosed fluid reductant released during the second injection event based on the second target flow rate.

Abstract: A controller includes a switching delay circuit structured to determine an open delay time and a close delay time for a reductant injector, each based on battery voltage and reductant injector coil temperature. A dosing circuit is structured to determine an open time that the armature pin must be in the fully open position so as to cause the injector to inject a first quantity of reductant. An actuation time is determined based on each of the open time, the open delay time, and the close delay time. The actuation time relates to a time that the coil must be energized so as to cause the injector to inject the first quantity of reductant. A switching command signal is transmitted to the injector to energize the coil for the calculated actuation time so as to cause the injector to inject the first quantity of reductant into an exhaust gas stream.

Abstract: According to one representative embodiment, an apparatus for controlling reductant dosing in an SCR catalyst system having a reductant injection system configured to inject reductant into an exhaust gas stream includes a controller, an actual reductant dosing rate module, and a reductant doser compensation module. The controller is configured to determine a reductant dosing rate command representing a desired reductant dosing rate. The actual reductant dosing rate module is configured to determine a predicted actual reductant dosing rate based at least partially on the reductant dosing rate command. The reductant doser compensation module is configured to determine a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate. The reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.

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: According to one representative embodiment, an apparatus for reducing NOx emissions in an engine exhaust gas stream of an engine system having a selective catalytic reduction (SCR) system with an SCR catalyst positioned downstream of a reductant injector includes a NOx reduction target module and a reductant module. The NOx reduction target module is configured to determine a NOx reduction requirement, which includes an amount of NOx in the exhaust gas stream to be reduced on the SCR catalyst. The reductant module is configured to determine the amount of reductant added to the exhaust gas stream to achieve the NOx reduction requirement. The amount of reductant added to the exhaust gas stream is a function of at least one ammonia storage characteristic of the SCR catalyst, at least one reductant-to-ammonia conversion characteristic, and a conversion capability of an AMOX catalyst in exhaust receiving communication with the SCR catalyst.

Abstract: For example, according to one representative embodiment, an apparatus for reducing NOx emissions in an engine exhaust includes a NOx reduction target module configured to determine a NOx reduction requirement. The apparatus also includes a tailpipe NOx module configured to determine a sensed amount of NOx exiting the engine system and a signal correction algorithm module configured to determine a corrected amount of NOx exiting the engine system based at least partially on the sensed amount of NOx exiting the engine system. The apparatus also includes a feedback ammonia target module configured to determine a feedback ammonia addition requirement. The feedback ammonia addition requirement includes an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement in response to the corrected amount of NOx exiting the engine system. The apparatus also includes a reductant target module that is configured to determine a reductant injection requirement.

Abstract: Various embodiments of an apparatus, system, and method are disclosed for reducing NOx emissions on an SCR catalyst. For example, according to one representative embodiment, an apparatus for reducing NOx emissions in an engine exhaust includes a NOx reduction target module that is configured to determine a NOx reduction requirement that includes an amount of NOx in the exhaust gas stream to be reduced on a selective catalytic reduction (SCR) catalyst. The apparatus also includes an ammonia target module that is configured to determine an ammonia addition requirement that includes an amount of ammonia added to the exhaust gas stream to achieve the NOx reduction requirement. The apparatus also includes a reductant target module that is configured to determine a reductant injection requirement that includes an amount of reductant added to the exhaust gas stream to achieve the ammonia addition requirement.

Abstract: According to one representative embodiment, an apparatus for controlling reductant dosing in an SCR catalyst system having a reductant injection system configured to inject reductant into an exhaust gas stream includes a controller, an actual reductant dosing rate module, and a reductant doser compensation module. The controller is configured to determine a reductant dosing rate command representing a desired reductant dosing rate. The actual reductant dosing rate module is configured to determine a predicted actual reductant dosing rate based at least partially on the reductant dosing rate command. The reductant doser compensation module is configured to determine a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate. The reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.