An ATS includes an SCR device and is connected to an internal combustion engine so as to receive an exhaust gas flow from at least one cylinder of the internal combustion engine when fuel is injected and combusted in such cylinder; an NH3 storage is increased in such SCR device after an engine shut off command has been detected, such that an increased NH3 storage is ready for a subsequent cold start of the internal combustion engine; the increase of NH3 storage is carried out by injecting a reducing agent in the ATS and by supplying an air flow towards the SCR device; such air flow flows through the cylinder after the fuel injection has been shut off.

Systems and apparatuses include an apparatus including an aftertreatment system control circuit structured to receive a signal indicative of an exhaust gas characteristic from a sensor, determine an aftertreatment system characteristic based on the exhaust gas characteristic, determine an acceptable input value responsive to the aftertreatment system characteristic, and control at least one of a fuel system actuator and an air handling actuator to achieve or substantially achieve the acceptable input value.

An exhaust treatment system comprising: a first dosage device, arranged to supply a first additive into said exhaust stream; a first reduction catalyst device, downstream of said first dosage device arranged for reduction of nitrogen oxides in said exhaust stream through the use of said first additive; a particulate filter, at least partly comprising a catalytically oxidizing coating, which is downstream of said first reduction catalyst device to catch soot particles, and to oxidize one or several of nitrogen oxide and incompletely oxidized carbon compounds in said exhaust stream; a second dosage device, downstream of said particulate filter to supply a second additive into said exhaust stream; and a second reduction catalyst device, downstream of said second dosage device for a reduction of nitrogen oxides in said exhaust stream, with the use of at least one of said first and said second additive.

An exhaust treatment system and method for the treatment of an exhaust stream from a combustion engine are provided. A first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in the exhaust stream is carried out by a first oxidation catalyst. Further, a value (NO2_1/NOx_1)det for a ratio between a first amount of nitrogen dioxide and a first amount of nitrogen oxides leaving said first oxidation catalyst is determined. Active control of at least one parameter related to the combustion engine is carried out, based on the determined value, so that the ratio is impacted. A first additive is supplied into the exhaust stream, following which a first reduction of the first amount of nitrogen oxides is carried out through a catalytic reaction in a catalytic filter, which consists of a particulate filter with an at least partly catalytic coating with reduction characteristics. The catalytic filter is arranged for catching and oxidizing of soot particles, and to carry out the first reduction of the first amount of nitrogen oxides using the first additive.

A method for operating an aftertreatment system of an engine is disclosed. The method includes measuring, using one or more sensors, at least one operating parameter of the engine system; estimating, by a controller, a mass of hydrocarbon retained by an aftertreatment component using the at least one operating parameter; determining, by the controller, a percent load of hydrocarbon using the mass of hydrocarbon; comparing, by the controller, the percent load to a predetermined hydrocarbon load threshold; and providing at least one alert indicating a need to initiate a stepwise increase in an engine power to one or more predetermined engine speeds for one or more predetermined durations, if the percent load exceeds the predetermined hydrocarbon load threshold.

The disclosure is intended to oxidize PM deposited in a filter in a suitable manner. Provision is made for a filter of wall flow type, a temperature raising unit to raise the temperature of the filter from a downstream side thereof, an exhaust gas shut-off valve, and a controller. The controller controls a flow of exhaust gas in the filter by once fully closing the exhaust gas shut-off valve and then fully opening it when the flow rate of the exhaust gas is equal to or larger than a predetermined flow rate, so as to cause PM to move to a downstream side portion in the filter in the direction of flow of exhaust gas, and carries out regeneration processing which oxidizes the PM by using the temperature raising unit after the controller has caused the PM to move to the downstream side portion of the filter.

A mixing device includes a case surrounding a blowing section of a filter or a catalyst; an upper pipe segment having an opening facing a direction opposite to the blowing section and tilted relative to the vertical direction so that the more the upper pipe segment goes vertically downward, the closer it gets to the blowing section; a lower pipe segment bent from a lower end of the upper pipe segment and tilted relative to the vertical direction so that the more it goes vertically downward, the further away it gets from the blowing section, the lower pipe segment extending out from the case and connected to a selective catalytic reduction device; and an injector attached to the case and injecting a liquid additive toward an area faced by the opening, the area being located outside the upper pipe segment in the case.

A method for monitoring particulate filter disposed in an exhaust aftertreatment system of an internal combustion engine includes determining, via a differential pressure sensor, a pressure differential across the particulate filter, and determining an initial parameter associated with soot loading on the particulate filter based upon the pressure differential. A first adjustment to the soot loading is determined based upon a passive regeneration effect, a second adjustment to the soot loading is determined based upon an off-engine temperature effect, and a third adjustment to the soot loading is determined based upon occurrence of an interrupted regeneration event. A final parameter associated with soot loading on the particulate filter is determined based upon the initial parameter and the first, second and third adjustments.

Methods and systems are provided for an exhaust gas aftertreatment system. In one example, a method may include limiting ammonia desorption from a catalyst in response to an increase in driver demand by activating an electric motor.

The present disclosure relates to an exhaust gas post-processing apparatus and a control method therefore. The exhaust gas post-processing apparatus and the control method therefore according to the present disclosure are provided with a pressure sensor on an exhaust gas line and a sensor on front/rear ends of the exhaust gas post-processing apparatus which can measure the concentration and the quantity of nitrogen oxides. Consequently, forced regeneration of the exhaust gas post-processing apparatus can be performed by determining whether the back pressure is increased or whether the reduction efficiency of nitrogen oxides becomes poor.