Abstract: An aftertreatment system including a method which provides a selective catalytic reduction (SCR) catalyst disposed in an exhaust stream of an engine; determines that an ammonia pre-load condition for the SCR catalyst is present; determines a first amount of ammonia pre-load in response to the ammonia pre-load condition; injects an amount of ammonia or urea into the exhaust stream in response to the first amount of ammonia; and adsorbs a second amount of ammonia onto the SCR catalyst in response to injecting an amount of ammonia or urea, where the second amount of ammonia is either the injected amount of ammonia or an amount of ammonia resulting from hydrolysis from the injected amount of urea.

Abstract: An exhaust aftertreatment process including providing a selective catalytic reduction (SCR) catalyst disposed in an exhaust stream of an internal combustion engine; determining that a temperature of the exhaust stream is not within an NH3 based SCR range; and providing an amount of unburned hydrocarbon (UHC) to the SCR catalyst in response to the temperature of the exhaust stream not being within an NH3 based SCR range.

Abstract: A method includes determining whether selective catalytic reduction (SCR) test conditions are present, and in response to the SCR test conditions being present, operating an SCR aftertreatment system at a number of reduced ammonia to NOx ratio (ANR) operating points. The method further includes determining a deNOx efficiency value corresponding to each of the ANR operating points. The method further includes determining a reductant correction value in response to the deNOx efficiency values corresponding to each of the ANR operating points, and providing a reductant injection command in response to the reductant correction value.

Abstract: A system is described for producing an elevated exhaust temperature and reduced NOx output for an engine. The system includes an internal combustion engine having a common rail fuel system, an exhaust pressure modulation device for the internal combustion engine, and a controller structured to functionally execute operations for elevating the exhaust temperature and reducing the NOx output. The controller determines a desired engine outlet exhaust temperature, an engine speed, and an engine load. In response to the desired engine outlet exhaust gas temperature, the engine speed, and the engine load, the controller determines an exhaust pressure increase command and a fuel injection command including at least one post-injection event. The common rail fuel system is responsive to the fuel injection command, and the exhaust pressure modulation device is responsive to the exhaust pressure increase command.

Abstract: A system is provided for enhancing aftertreatment regeneration capability. The system includes an internal combustion engine producing an exhaust gas stream and an aftertreatment component that treats the exhaust gas stream, where the aftertreatment component includes a desired inlet exhaust gas temperature. The system includes an exhaust gas pressure device that modulates an exhaust pressure value, and a fuel injection system that provides a post-injection event. The system includes a controller that provides an exhaust pressure command and a fuel injection command in response to determining that a temperature of the exhaust gas stream is lower than the desired inlet exhaust gas temperature. The exhaust gas pressure device is responsive to the exhaust pressure command and the fuel injection system is responsive to the fuel injection command.

Abstract: A method includes providing a system having a fluid flow, a fuel injector and an oxygen sensor disposed in the fluid flow, where the oxygen sensor is downstream of the fuel injector. The method includes determining a first air fuel ratio, changing an injection rate of the fuel injector and determining a second air fuel ratio, and determining a fault value for the fuel injector from the first air fuel ratio and the second air fuel ratio. The method further includes determining the fault value for the fuel injector by determining a difference between the first air fuel ratio and the second air fuel ratio, and by determining that the fault value is positive in response to the difference being lower than a passing threshold value. The method includes changing injection rates of the fuel injector for specified periods of time short enough to significant disruption of system temperatures.

Abstract: An exhaust gas stream aftertreatment system and method achieves high efficiency NOx reduction in exhaust gas emissions by arranging a selective catalytic reduction (SCR) catalyst element upstream from a NOx adsorber catalyst. In an exemplary embodiment, a reductant is introduced into the exhaust gas stream, exposing the exhaust gas stream containing the reductant to a selective catalytic reduction (SCR) catalyst element, and exposing the exhaust gas stream that was exposed to the SCR catalyst element to a NOx adsorber catalyst element. The NOx adsorber catalyst element can be regenerated by temporarily reducing an oxygen concentration in an exhaust gas stream to reduce the ? of the exhaust gas stream. While the oxygen concentration is reduced, reductant is introduced into the exhaust gas stream at a rate that achieves a fuel-rich condition, and the fuel rich exhaust stream is exposed to the NOx adsorber catalyst element.

Abstract: One embodiment is a method including operating an SCR system at a plurality of commanded ammonia to NOx input ratios, providing a plurality of data indicating NOx output from the SCR system for the plurality of commanded ammonia to NOx input ratios, and evaluating the plurality of data to diagnose the SCR system. Additional embodiment are methods, systems, and apparatuses including SCR diagnostics. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Abstract: An apparatus, system, and method are disclosed for determining the distribution of particulate matter on a particulate filter. The apparatus, in one embodiment, determines a first distribution of particulate matter by comparing the pressure change across the particulate filter with a change in engine operating conditions. The apparatus may include an input module for receiving input corresponding to engine operating conditions and input from a differential pressure sensor and a feedback module to determine a first distribution of particulate matter. The apparatus may further include a feed forward module for determining a particulate distribution trend and a selection control module to combine the first distribution of particulate matter with the particulate distribution trend to determine a second distribution of particulate matter. The distribution may be defined as a uniform distribution factor in certain embodiments.

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: Inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine may comprise reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range. Reducing the oxygen concentration of the exhaust gas supplied to the particulate filter may include any one or combination of reducing the oxygen concentration of intake air supplied to the intake manifold, reducing the air portion of the air-to-fuel ratio of the air-fuel mixture supplied to the engine and removing oxygen from the exhaust gas supplied to the particulate filter.

Abstract: An OBD system that diagnoses on board the condition of NOx adsorber catalysts in diesel engines and that relies on existing mass-produced exhaust gas oxygen sensor, also known as lambda sensor, technology, and the following established phenomena. In a reducing environment, typical exhaust gas oxygen (lambda) sensors have different sensitivities to various reductants, with sensitivity decreasing in this order: H2>CO>short-chain hydrocarbons>long-chain hydrocarbons. In the process of regeneration of the NOx adsorber catalyst, the original reductant may evolve into a different reductant species, e.g., via reactions such as a water-gas shift (WGS), a reforming, a partial oxidation, etc. This leads to a difference in exhaust gas oxygen sensor readings between the inlet to the catalyst and outlet from the catalyst. It has been observed in diesel engine testing that the ability of the NOx adsorber catalyst to perform such a reductant evolution is correlative to the catalyst's NOx reduction capability.

Abstract: According to one representative embodiment, an apparatus for determining the degradation of a selective catalytic reduction (SCR) catalyst of an engine exhaust aftertreatment system includes a system properties module configured to store at least one system dynamics property value of the exhaust system at a first time and receive the at least one system dynamics property value of the exhaust aftertreatment system at a second time subsequent to the first time. The apparatus also includes a system dynamics module configured to determine a storage capacity of the SCR catalyst based on a comparison between the at least one system dynamic property value at the first time and the at least one system dynamic property value at the second time. Additionally, the apparatus includes an SCR catalyst degradation factor module configured to determine an SCR catalyst degradation factor based at least partially on the storage capacity of the SCR catalyst.

Abstract: An apparatus, system, and method are disclosed for determining a regeneration cycle thermal ramp. A thermal ramp module estimates a regeneration cycle thermal ramp. A soot content module estimates a soot content for a filter. In one embodiment, an oxygen content module estimates an oxygen gas concentration for the filter. A thermal profile module calculates a thermal profile for the filter as a function of the soot content and the thermal ramp. The thermal profile module may also include the oxygen content in the thermal profile calculation. A test module modifies the regeneration cycle thermal ramp if the thermal profile exceeds a thermal threshold. In one embodiment, a communication module may communicate a warning if the thermal ramp exceeds a warning threshold.

Abstract: One embodiment is a unique system of EGR catalyzation with reduced EGR heating. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

Abstract: A system and method are provided for controlling regeneration of exhaust gas aftertreatment components coupled to an internal combustion engine. For example, the particulate load of a particulate filter is monitored and a road speed of the vehicle is determined. If the particulate load is greater than a particulate load threshold and the road speed is greater than a road speed threshold, regeneration of the particulate filter is initiated. As another example, the sulfur oxide load (SOx) of a NOx catalyst is also monitored, and if the SOx load is greater than a SOx threshold while the particulate filter is being regenerated, regeneration of the particulate filter is terminated and SOx regeneration of the NOx catalyst is initiated.

Abstract: A NOx adsorber catalyst may comprise a housing defining an inlet configured to receive exhaust gas produced by an internal combustion engine, an outlet and a chamber between the inlet and the outlet. A NOx adsorber element may be positioned in the chamber adjacent to the inlet. The NOx adsorber element may be configured to trap NOx in the exhaust gas during lean fuel operation of the engine, and to release the trapped NOx and reduce the released NOx to nitrogen during rich fuel operation of the engine. A hydrocarbon trap may be positioned in the chamber between the NOx adsorber element and the outlet. The hydrocarbon trap may be configured to trap hydrocarbons that travel through the NOx adsorber element during the rich fuel operation of the engine. The trapped hydrocarbons may be oxidized by oxygen present in the exhaust gas during lean fuel operation following rich fuel operation.

Abstract: A NOx adsorber catalyst may comprise a housing defining an inlet configured to receive exhaust gas produced by an internal combustion engine, an outlet and a chamber between the inlet and the outlet. A NOx adsorber element may be positioned in the chamber adjacent to the inlet. The NOx adsorber element may be configured to trap NOx in the exhaust gas during lean fuel operation of the engine, and to release the trapped NOx and reduce the released NOx to nitrogen during rich fuel operation of the engine. A hydrocarbon trap may be positioned in the chamber between the NOx adsorber element and the outlet. The hydrocarbon trap may be configured to trap hydrocarbons that travel through the NOx adsorber element during the rich fuel operation of the engine. The trapped hydrocarbons may be oxidized by oxygen present in the exhaust gas during lean fuel operation following rich fuel operation.

Abstract: A system and method are provided for controlling regeneration of exhaust gas aftertreatment components coupled to an internal combustion engine. For example, the particulate load of a particulate filter is monitored and a road speed of the vehicle is determined. If the particulate load is greater than a particulate load threshold and the road speed is greater than a road speed threshold, regeneration of the particulate filter is initiated. As another example, the sulfur oxide load (SOx) of a NOx catalyst is also monitored, and if the SOx load is greater than a SOx threshold while the particulate filter is being regenerated, regeneration of the particulate filter is terminated and SOx regeneration of the NOx catalyst is initiated.

Abstract: Inhibiting uncontrolled regeneration of a particulate filter fluidly coupled to an exhaust manifold of an internal combustion engine may comprise reducing an oxygen concentration of exhaust gas supplied to the particulate filter if active regeneration of the particulate filter is in progress and rotational speed of the engine speed thereafter drops to an idle speed range from an elevated rotational speed that is greater than the idle speed range. Reducing the oxygen concentration of the exhaust gas supplied to the particulate filter may include any one or combination of reducing the oxygen concentration of intake air supplied to the intake manifold, reducing the air portion of the air-to-fuel ratio of the air-fuel mixture supplied to the engine and removing oxygen from the exhaust gas supplied to the particulate filter.