A dosing control unit (DCU) may receive operational information associated with a selective catalytic reduction (SCR) aftertreatment system. The DCU may generate a deposit prediction, associated with the SCR aftertreatment system, based on the operational information. The deposit prediction may include information that identifies a predicted size of a deposit in a dosing zone of a plurality of dosing zones associated with the SCR aftertreatment system. The deposit prediction may be generated using a deposit growth model associated with predicting sizes of deposits in the plurality of dosing zones. The DCU may select a dosing scheme, of a plurality of dosing schemes, based on the deposit prediction. The DCU may implement the selected dosing scheme in order to cause diesel exhaust fluid (DEF) to be dosed in the plurality of dosing zones in accordance with the selected dosing scheme.

A reducing agent supply device includes a tank, an adding valve, a pump, and an electronic control unit. The adding valve is configured to receive the reducing agent supplied from the tank and inject the reducing agent. The pump is configured to send the reducing agent from the tank and suction the reducing agent back into the tank. The electronic control unit is configured to open the adding valve and suction the reducing agent back into the tank as a purge control when the internal combustion engine is commanded to stop. The electronic control unit is configured to increase an amount of a return suction of the reducing agent during the purge control as an amount of the reducing agent, remaining in a supply path and the adding valve when the stop command is given, increases.

A method for operating an internal combustion engine of a motor vehicle, which has an exhaust gas system that exhaust gas from at least one combustion chamber of the internal combustion chamber can flow through and includes at least one nitrogen oxide storage catalyst, at least one particulate filter, and at least one selective catalytic reduction (SCR) catalyst.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine and a first treatment element positioned within the exhaust gas pathway such that the first treatment element is close coupled to the engine. The first treatment element includes a NO.sub.x storage element. A first injector is configured to selectively introduce a first reductant into the exhaust gas pathway upstream of the first treatment element, and a second injector is configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element. The system includes a second treatment element positioned within the exhaust gas pathway downstream of the second injector, and the second treatment element includes a selective catalytic reduction (SCR) element.

A process for detecting reductant deposits includes accessing data indicative of signal output from a radiofrequency sensor positioned proximate a decomposition reactor tube; comparing the data indicative of signal output from the radiofrequency sensor to a deposit formation threshold; and activating a deposit mitigation process responsive to the data indicative of signal output from the radiofrequency sensor exceeding the deposit formation threshold.

An automotive exhaust aftertreatment system for reducing effluents, such as nitrous oxides (NOx), in exhaust gasses passing through the system. The automotive exhaust aftertreatment system includes a dosing unit configured to inject primary and secondary reductant fluids into exhaust gasses based on various strategies to optimize operation of the system.

An exhaust aftertreatment system for an internal combustion engine includes a selective catalytic reduction (SCR) device, an injection system disposed to inject reductant into the exhaust pipe upstream of the SCR device. A single ammonia sensor is disposed to monitor an exhaust gas feedstream downstream of the SCR device. A controller is in communication with the single ammonia sensor and the internal combustion engine and operatively is connected to the injection system. The controller includes an instruction set that is executable to monitor, via the single ammonia sensor, a magnitude of ammonia in the exhaust gas feedstream downstream of the SCR device and determine NOx efficiency of the SCR device based upon the magnitude of ammonia in the exhaust gas feedstream downstream of the SCR device. A fault is detected in the SCR device based upon the NOx efficiency.

A dosing module includes: a frame assembly comprising a plurality of panels; a first manifold configured to separately receive reductant and air and including: a first connector, and a second connector; and a dosing tray including: a base panel, a second manifold configured to separately receive the air and the reductant and provide the air and the reductant back to the first manifold, a third connector selectively coupled to the first connector, and a fourth connector selectively coupled to the second connector. When the third connector is coupled to the first connector and the fourth connector is coupled to the second connector, the reductant or air is routed to the first connector, from the first connector to the third connector, from the third connector to the fourth connector, from the fourth connector to the second connector, and from the second connector outside of the dosing module.

Embodiments described herein methods can be used in particulate filter regeneration, such as particulate filters used for filtering the exhaust of an engine, e.g., a diesel engine. Systems herein can be configured to dispense combustion gas(es) into housing were a particulate filter is contained and to ignite the combustion gases. Methods for conducting a safety verification process of such systems are disclosed, as well as methods for regenerating the filters. Still other embodiments are described.

An internal combustion engine, exhaust system, exhaust gas treatment device includes an housing (18) including a housing inlet (34) and a housing outlet (60). An exhaust gas treatment unit (28), in the housing, includes an inlet (32) following the housing inlet and an outlet (38). An SCR catalytic converter device (30), in the housing, includes an SCR catalytic converter device inlet (54) following the exhaust gas treatment unit outlet and an SCR catalytic converter device outlet (56). A reactant releasing device (52) releases reactant upstream of the SCR catalytic converter device inlet. An exhaust gas duct (42), formed in an exhaust gas pipe (44), leads in the housing from the exhaust gas treatment unit outlet to the SCR catalytic converter device inlet, whereby exhaust gas leaving the SCR catalytic converter device at the SCR catalytic converter device outlet flows around the exhaust gas pipe in at least some areas.