Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.

An internal-combustion-engine warm-up apparatus includes: a post-processing apparatus; a heater arranged upstream of the post-processing apparatus on the exhaust path; a circulation path where air having passed through the post-processing apparatus is fed back to an upstream side of the heater; an air pump that is a blower that feeds air heated by the heater to the post-processing apparatus; a coolant flow path; a heat exchanger; and a control apparatus that controls operation of the heater and the blower, and in a state where the engine is stopped, the control apparatus causes the heater and the air pump to operate, and causes the air heated by the heater to be supplied to the post-processing apparatus and the heat exchanger.

Methods and systems are provided for an aftertreatment system. In one example, a method comprises regenerating a NO.sub.x trap during an engine shut-down event. The method further comprises reversing a direction of flow of a gas through a HP-EGR passage during the regenerating.

The present invention relates to a method for controlling an internal combustion engine arrangement (100) connected to an exhaust gas aftertreatment system (200), wherein the method is arranged to control a gas heating device (122), as well as a gas feeding arrangement to direct a flow of intake air through the exhaust gas recirculation conduit (112) from the intake system to the exhaust system, the flow of intake air being directed through the gas heating device before the intake air enters the exhaust gas aftertreatment system, in response to determining a requested start of the internal combustion engine to heat the aftertreatment system before starting the engine.

An exhaust control system includes: a temperature control module configured to, in response to a shutdown of an engine, turn on an air pump that, when on, pumps air into an exhaust system of the engine upstream of a selective catalytic reduction (SCR) catalyst; a target module configured to, while the air pump is on and the engine is off in response to the shutdown, selectively determine a target rate of injection of a diesel exhaust fluid (DEF) by a DEF injector based on increasing a present amount of ammonia stored by the SCR catalyst to at least a predetermined amount of ammonia; and a DEF control module configured to, while the air pump is on and the engine is off in response to the shutdown, control injection of the DEF by the DEF injector upstream of the SCR catalyst based on the target rate.

A heating device for an exhaust system of an internal combustion engine; the heating device has: a first tubular body wherein a combustion chamber is obtained; a fuel injector to inject fuel into the combustion chamber; an inlet opening, which is obtained through the first tubular body and can be connected to a fan to receive an air flow, which is directed into the combustion chamber; a hot air outlet opening to let hot air out of the combustion chamber; an outlet duct, which originates from the outlet opening; a spark plug which is mounted through a side wall of the first tubular body to trigger the combustion of a mixture of air and fuel; and a labyrinth, which surrounds a side wall of the tubular body, starts from the inlet opening, ends in the combustion chamber, and the air must necessarily flow out of the inlet opening until reaching the combustion chamber.

An arrangement for a marine vessel, comprising a combustion unit arranged in an engine room of the marine vessel, an exhaust gas cleaning system in flow connection with the combustion unit and being arranged for receiving and for cleaning the exhaust gas from the combustion unit to a cleaned exhaust gas, a cleaned gas exhaust pipe being in flow connection with the exhaust gas cleaning system and arranged for receiving the cleaned exhaust gas, a plume control system, comprising an air intake for taking in ambient air, a heater for heating the ambient air producing heated air, and a gas mixer placed in the cleaned gas exhaust pipe and arranged for mixing the cleaned exhaust gas in the cleaned gas exhaust pipe with the heated air resulting in an exhaust gas mixture that is blown out into the atmosphere via the one or more exhaust gas outlets.

A method and a corresponding apparatus are provided for preconditioning an exhaust gas system (100) for discharging and purifying combustion exhaust gases of an internal combustion engine (1), in particular an internal combustion engine (1) of a motor vehicle (200). The method includes operating, air being heated by a heating element (8) in the exhaust gas system (100) to heat air in the exhaust gas system (100), operating a fan in the exhaust gas system (100) for producing a hot air stream with the heated air, using the hot air stream for heating a first catalytic converter (7) of the exhaust gas system (100) to a minimum operating temperature.

A gas introduction assembly introduces gas, in particular air, into an exhaust gas system of an internal combustion engine. The exhaust gas system has an interior. The gas introduction assembly includes a gas introduction region positioned in the interior of the exhaust gas system. The gas introduction region is constructed at least partially with porous material.

Methods and systems are provided for an aftertreatment system. In one example, a method comprises regenerating a NO.sub.x trap during an engine shut-down event. The method further comprises reversing a direction of flow of a gas through a HP-EGR passage during the regenerating.