A controller for an internal combustion engine includes a fuel introduction process of introducing an air-fuel mixture containing fuel injected by a fuel injection valve into an exhaust passage without burning the air-fuel mixture in a cylinder. The fuel introduction processor is configured to perform, during the execution of the fuel introduction process, a determination process of determining whether afterfire, in which the air-fuel mixture burns at an upstream side of a three-way catalyst device in the exhaust passage, has occurred and a stopping process of stopping the fuel introduction process when determining in the determination process that the afterfire has occurred.

An aftertreatment system includes a multipoint injector configured to be operatively coupled to an exhaust tube of the aftertreatment system. The multipoint injector comprises an injector body having a circumferential wall. A plurality of orifices extend through the circumferential wall of the injector body. Each of the plurality of orifices is located at a different circumferential position of the circumferential wall and is configured to insert reductant into an exhaust gas flow path defined by the exhaust tube.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway that receives exhaust gas from the engine, a temperature sensor configured to generate a temperature signal associated with a temperature of the exhaust gas at a position along the exhaust gas pathway, and a reductant source. The system also includes first and second injectors in fluid communication with the reductant source. The first and second injectors are configured to inject reductant into the exhaust gas pathway at first and second rates. The system also includes a first treatment element positioned downstream of the first injector and within the exhaust gas pathway, and a controller in communication with the temperature sensor. The controller is configured to receive the temperature signal from the temperature sensor and adjust at least one of the first rate or the second rate based at least in part on the temperature signal.

The present disclosure relates to a system and a method for removing noxious gas from cleaning liquid discharged from an exhaust gas treatment apparatus and, more particularly, to a system and a method for removing noxious gas from cleaning liquid discharged from an exhaust gas treatment apparatus, which are capable of adjusting the discharge rate of the cleaning liquid in a noxious gas removal unit, which removes noxious gas remaining in a gaseous state in the cleaning liquid discharged from the exhaust gas treatment apparatus and discharges the cleaning liquid from which the noxious gas in the gaseous state has been removed, on the basis of a result of measurement of the level of the cleaning liquid in the noxious gas removal unit.

A method of adjusting the dosage of a reductant for an SCR catalyst, comprising: determining (110) an expected temperature profile in at least one axial section of the catalyst (70) for a defined period of time (t.sub.Sim); firstly simulating (120) the resulting amount of reductant beyond the at least one section of the catalyst with a first defined dosage of the reductant depending on the expected temperature profile determined; comparing the first simulated amount of reductant with a limit; depending on the result of the comparison, choosing a second defined dosage and secondly simulating (130, 160) a resulting amount of reductant beyond the at least one section of the catalyst (70) with the second dosage; comparing the second simulated amount of reductant with the limit; and adjusting (140, 150, 170, 180, 190, 195) the dosage for injection of the reductant into the catalyst based on the first and/or second comparison.

An aftertreatment system includes a reductant source, a junction, a dosing pump module, a valve assembly, and a dosing module. The reductant source stores reductant. The junction receives the reductant from the reductant source. The dosing pump module receives the reductant from the junction and selectively provides the reductant to a first conduit. The valve assembly receives the reductant from the first conduit. The valve assembly is operable between a first state, where the valve assembly provides the reductant to the junction, and a second state, where the valve assembly provides the reductant to a second conduit. The dosing module receives the reductant from the second conduit when provided by the valve assembly. The dosing module is configured to dose exhaust gases with the reductant when provided by the valve assembly.

Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injections into the exhaust gas. Controlling the reductant injections includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductants to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injectors to inject the computed amount of reductants.

Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injections into the exhaust gas. Controlling the reductant injections includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductants to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injectors to inject the computed amount of reductants.

This degradation diagnosis device for an exhaust purification system makes it possible to discover degradation of a constituting component in an exhaust purification system at an early stage. The degradation diagnosis device for an exhaust purification system that purifies exhaust gas discharged from an internal combustion engine into an exhaust pipe is provided with: a degradation degree estimation unit that estimates the degree of degradation due to corrosion of a constituting component in the exhaust purification system based on the temperature of exhaust gas and the amount of a reducing agent injected into the exhaust pipe; a determination unit that determines whether the degradation degree estimated by the degradation degree estimation unit exceeds a predetermined threshold; and an output unit that outputs the result of determination made by the determination unit.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway that receives exhaust gas from the engine, a temperature sensor configured to generate a temperature signal associated with a temperature of the exhaust gas at a position along the exhaust gas pathway, and a reductant source. The system also includes first and second injectors in fluid communication with the reductant source. The first and second injectors are configured to inject reductant into the exhaust gas pathway at first and second rates. The system also includes a first treatment element positioned downstream of the first injector and within the exhaust gas pathway, and a controller in communication with the temperature sensor. The controller is configured to receive the temperature signal from the temperature sensor and adjust at least one of the first rate or the second rate based at least in part on the temperature signal.