Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

A method for preconditioning at least a part of an engine system of a vehicle. The engine system includes an engine and an exhaust aftertreatment system, EATS. The method providing predicted vehicle operational information comprising a vehicle operational initialization time and predicted engine operation, determining whether or not cold-start emissions of the predicted engine operation achieves a threshold criterium, in response to achieving the threshold criterium, preconditioning at least a part of the engine system such that at least said part of the engine system is preconditioned at a time of the vehicle operational initialization time.

An exhaust aftertreatment system, EATS, for converting NOx emissions in exhaust gases from an engine. The EATS includes a fluid channel for providing a fluid pathway for the exhaust gases; a selective catalytic reduction, SCR, catalyst arranged in the fluid channel, the SCR catalyst being configured to store ammonia; an injector configured to inject a reductant for providing ammonia to the SCR catalyst, the injector being arranged upstream of the SCR catalyst; a fluid flow inducer configured to cause an induced fluid flow in at least a part of the fluid channel when the engine is turned off; and a controlling apparatus configured to precondition the EATS prior to engine start by injecting the reductant into the fluid channel, and transport the reductant into the SCR catalyst by the induced fluid flow to store ammonia in the SCR catalyst.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing defining an exhaust flow path for exhaust gases from the internal combustion engine, a selective catalytic reduction unit provided in the exhaust flow path for reducing nitrogen oxides, a urea dosing device for adding urea to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the urea with exhaust gases upstream of the selective catalytic reduction unit. The exhaust aftertreatment system further comprises an air inlet valve provided upstream of the mixer device for introducing air into the exhaust flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the exhaust flow path via the air inlet valve.

A control module for an aftertreatment system that includes a selective catalytic reduction (SCR) catalyst and an oxidation catalyst, comprises a controller configured to be operatively coupled to the aftertreatment system. The controller is configured to determine an actual SCR catalytic conversion efficiency of the SCR catalyst. The controller determines an estimated SCR catalytic conversion efficiency based on a test sulfur concentration selected by the controller. In response to the estimated SCR catalytic conversion efficiency being within a predefined range, the controller sets the test sulfur concentration as a determined sulfur concentration in a fuel provided to the engine. The controller generates a sulfur concentration signal indicating the determined sulfur.

A method (200) for heating an exhaust system (120) downstream of an internal combustion engine (1) by means of an electric heating device (14, 15). In one example, the method includes determining a current temperature (t_EHC, t_EHC{circumflex over ( )}Us, t_Cat) in the exhaust system (120), determining a heating demand (t_EHC{circumflex over ( )}Des) based on the determined current temperature (t_Cat) and a target temperature, calculating a required amount of heat (Pwr{circumflex over ( )}Des) on the basis of the heating demand and an amount of energy required to heat the electric heating device (14, 15), and controlling (Pwr{circumflex over ( )}Req) the electric heating device (14, 15) to generate the calculated amount of heat.

Described herein are various embodiments of a reductant decomposition system. According to one representative embodiment, the reductant decomposition system includes an exhaust gas chamber including an inlet and outlet. The system also includes a first exhaust gas distribution component positioned within the chamber and communicable in exhaust gas receiving communication with the outlet. The first exhaust gas distribution component causes swirling exhaust gas flow patterns within the exhaust gas chamber. Additionally, the system includes a second exhaust gas distribution component positioned within the chamber and communicable in exhaust gas providing communication with the inlet. The second exhaust gas distribution component includes features that cause a swirling exhaust gas flow pattern within a space defined by the second exhaust gas distribution component. Further, the system includes a reductant injector coupled to the exhaust gas chamber. The reductant injector is communicable in reductant injecting communication with exhaust gas within the chamber.

An apparatus includes a dosing module structured to suspend dosing in an exhaust aftertreatment system; a selective catalytic reduction (SCR) inlet NOx module structured to interpret SCR inlet NOx data and an SCR inlet temperature; a SCR outlet NOx module structured to interpret SCR outlet NOx data; and a system diagnostic module structured to determine an efficiency of a SCR system based on the SCR inlet and outlet NOx data over a range of SCR temperatures, wherein the system diagnostic module is further structured to determine a state of at least one of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and the SCR system based on the SCR efficiency at an elevated SCR temperature range and the SCR efficiency at a relatively lower SCR temperature range relative to a high SCR efficiency threshold and a low SCR efficiency threshold.

An exhaust purification system includes: a NOx reduction catalyst for reducing and purifying NOx in an exhaust gas; a catalyst regeneration control module for executing a catalyst regeneration process of restoring a NOx purification capacity of the NOx reduction catalyst by switching an air-fuel ratio of the exhaust gas from a lean state to a rich state by using in parallel an air system control to reduce an intake air amount and an injection system control to increase a fuel injection amount; an exhaust gas temperature sensor that is provided on a downstream side of the NOx reduction catalyst on an exhaust passageway; a catalyst temperature estimating module for estimating a catalyst temperature of the NOx reduction catalyst; a temperature sensor value estimating module for estimating a sensor value of the exhaust gas temperature sensor; and an abnormality determination module for determining on an abnormality of a catalyst regeneration process.

There is provided an exhaust gas purification system including: a NOx storage-reduction catalyst that is provided in an exhaust system of an internal combustion engine to reduce and purify NOx in exhaust gas; a degree of deterioration estimation module 120 for estimating a degree of deterioration of the NOx storage-reduction catalyst; a regeneration control unit 100 for executing a regeneration process in which exhaust gas is enriched so as to restore a NOx storage capacity of the NOx storage-reduction catalyst; an interval setting module for setting a target interval from an end of the regeneration process to a start of the subsequent regeneration process by the regeneration control unit; and an interval target value correction module for correcting the target interval based on the degree of deterioration that is estimated by the degree of deterioration estimation module.