The present disclosure relates to a method for determining urea feeding in an exhaust gas aftertreatment system (100,200), the exhaust gas aftertreatment system (100,200) being connectable to an internal combustion engine (101,201) operating under an engine operating condition, the system (100,200) comprising a first Selective Catalytic Reduction (SCR1) system comprising a first selective reduction catalyst (SCR1c) and a first doser (103,203) configured for feeding urea upstream the SCR1 system, at least one Particulate Filter (PF) downstream the SCR1 system or as a substrate for the SCR1c and a second Selective Catalytic Reduction (SCR2) system downstream the PF, the SCR2 system comprising a second selective reduction catalyst (SCR2c) and a second doser (104,204) configured for feeding urea upstream the SCR2c, the method comprising the steps of estimating the amount of particles in the PF; and determining the amount of urea to be fed by the respective first and second doser (4,5) based on the engine operating condition and such that: a) the amount of particles in the PF is within a predefined particle amount range, and, b) the NOx level of the exhaust gas exiting the SCR2 system is within a predetermined NOx level range. The present disclosure also relates to an exhaust gas aftertreatment system (100,200) and a vehicle comprising the exhaust gas aftertreatment system (100,200), a computer program comprising program code means for performing the steps of the method, a computer readable medium carrying a computer program comprising program code means for performing the steps of the method and a control unit for controlling urea feeding in the exhaust gas aftertreatment system (100,200).

The present disclosure describes methods for evaluating ammonia storage capacity of a close-coupled SCR unit while remaining compliant with prescribed emissions limits, methods of controlling an emission aftertreatment system including multiple SCR units and emission management systems for a vehicle including an internal combustion engine and an emission aftertreatment system that includes two or more SCR units.

An apparatus for use with a combustion apparatus and an associated Selective Catalytic Reduction (‘SCR’) device, comprises a temperature sensing device configured to measure the temperature of an exhaust from the combustion apparatus; and an injection unit configured to inject hydrogen into a feed of oxidizer to the combustion apparatus. An amount of hydrogen is added to an oxidiser feed of the combustion apparatus sufficient to reach a temperature in the exhaust of at least about 270° C.

Methods and systems are provided for cylinder deactivation to reduce tailpipe emissions and increase exhaust temperature. In one example, a method may include operating a first set of cylinders in a first combustion cycle over modified eight strokes and a second set of cylinders in a second combustion cycle over modified four strokes. Each cylinder in the first set of cylinders may be selectively deactivated via a variable displacement engine (VDE) mechanism while each cylinder in the second set of cylinders may be selectively deactivated via an active decompression technology (ADT) mechanism.

Methods and systems are provided for maintaining efficiency of a catalyst that is positioned in an exhaust system downstream of an internal combustion engine. In one example, the catalyst may be heated via supplying fuel to a cylinder that does not combust the fuel. The fuel may be oxidized at the catalyst via excess oxygen in the exhaust system.

Systems, methods, and apparatuses are provided for increasing exhaust gas temperature. A system includes a valve and a controller coupled to the valve. The controller is structured to determine that a plurality of cylinders of an engine are active; compare an exhaust aftertreatment temperature to an exhaust aftertreatment temperature setpoint; and in response to the comparison, adjust an effective flow area for exhaust gas from the plurality of cylinders of the engine to increase an exhaust gas temperature.

To provide a controller and a control method for internal combustion engine which can set appropriately an angle interval for estimating the combustion state in accordance with change of a burning angle interval, and can reduce calculation processing load for estimation of the combustion state. A controller for internal combustion engine changes the estimation crank angle interval based on an operating condition of the internal combustion engine; calculates an increment of gas pressure torque by burning at each crank angle of the estimation crank angle interval; and estimates the combustion state of the internal combustion engine, based on the increment of gas pressure torque by burning in the estimation crank angle interval.

Methods and systems are provided for re-combustion of exhaust in a cylinder of a multi-cylinder engine in order to increase the temperature of the exhaust for enhancing catalytic conversion within the multi-cylinder engine. In one example, a method may include expelling combusted gases from the cylinder into an intake manifold via an intake valve during an exhaust stroke, in order to rebreathe in the combusted gases from the intake manifold via the intake valve in a subsequent intake stroke.

An aftertreatment device of a vehicle exhaust system includes an aftertreatment device. The aftertreatment device includes a body defining an inlet cone, an outlet cone, and a cavity therebetween. A heating element is disposed in the cavity. A catalyst is disposed in the cavity downstream of the heating element. A recirculation loop has a conduit with a first end connected to the outlet cone and a second end connected to the inlet cone. The recirculation loop further has an air-circulation device configured to recirculate heated air from the outlet cone to the inlet cone.

A method for operating an internal combustion engine of a drivetrain of a vehicle during launching. The vehicle has an exhaust-gas aftertreatment system for purifying exhaust gas of the engine. After a starting operation of the engine, the drivetrain is operated in a first operating state. In this first operating state, the engine is operated at idle, the exhaust-gas aftertreatment system is heated by the internal combustion engine, and a launch prohibition is active. The launch prohibition that is active in the first operating state prevents launching using the internal combustion engine. After a predefined state of the exhaust-gas aftertreatment system has been attained, the drivetrain is operated in a second operating state. The launch prohibition is inactive in the second operating state, such that launching using the engine is possible in the second operating state.