An exhaust gas purification apparatus includes: a catalyst device that is provided in an exhaust passage of an internal combustion engine; an exhaust ignition device that is provided upstream of the exhaust passage from the catalyst device; and a controller that controls a treatment of heating the catalyst device by adjusting supply of the air-fuel mixture to a region of the exhaust passage where the exhaust ignition device is provided and ignition of the air-fuel mixture by the exhaust ignition device, the controller includes an equivalence ratio setting unit that sets a target value of an equivalence ratio of the air-fuel mixture to a first equivalence ratio larger than 1 until a predetermined first time elapses from a start of supply of the fuel and sets the target value of the equivalence ratio of the air-fuel mixture to a second equivalence ratio smaller than 1 after the first time elapses.

When a temperature of a catalyst in an exhaust emission control device mounted in an exhaust system of an engine is equal to or higher than a predetermined temperature at a time of a request for stopping the engine, a hybrid vehicle including the engine and a motor continues fuel injection of the engine until satisfaction of a predetermined condition and stops fuel injection of the engine on satisfaction of the predetermined condition. When the temperature of the catalyst is lower than the predetermined temperature at the time of the request for stopping the engine, on the other hand, the hybrid vehicle immediately stops fuel injection of the engine.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a second exhaust manifold and exhaust gas to an exhaust passage via a first exhaust manifold. In one example, in response to an intake throttle being at least partially closed, intake air may be routed from the intake passage to the second exhaust manifold via an exhaust gas recirculation (EGR) passage where the intake air may be heated via an EGR cooler. The heated intake air may then be routed to an intake manifold, downstream of the intake throttle, via a flow passage coupled between the second exhaust manifold and the intake manifold.

A system includes an exhaust aftertreatment system including a particulate filter and a controller. The controller is configured to: receive information comprising a temperature regarding a filter of the aftertreatment system; and responsive to determining that the temperature regarding the filter is below a temperature threshold, command the engine to operate according to a first firing fraction. The first firing fraction may define a number of active cylinders of the engine relative to a total number of cylinders of the engine, and correspond to a predetermined temperature value of the filter.

A method of heating an aftertreatment system includes fulfilling a vehicle drive load of a vehicle via an electrical drivetrain of a vehicle hybrid powertrain, wherein the vehicle hybrid powertrain comprises the electrical drivetrain and an internal combustion engine; while the electrical drivetrain is fulfilling the vehicle drive load, operating the internal combustion engine to generate airflow for transport of heat through the aftertreatment system; and directing a heat source to raise a temperature through a selective catalytic reduction (SCR) device of the aftertreatment system.

A GDCI engine control system includes a heated catalyst in an engine exhaust port that is in close proximity to a combustion chamber and is used to heat rebreathed exhaust gases. The engine more quickly reaches operating temperatures, and emissions are reduced during cold running.

Methods and systems are provided for a close-coupled aftertreatment device. In one example, a system may include an engine comprising separate first and second overall exhaust lines, where a blow-off line branches off of the second overall exhaust line, and where the close-coupled aftertreatment device is arranged in the blow-off line and configured to receive exhaust gases during at least a cold-start of the engine.

A method for operating an internal combustion engine using an external exhaust-gas recirculation device with a recirculation setting device to set the flow rate of the recirculated exhaust gas and using a closing time setting device to adjust the closing time of the at least one inlet valve of the internal combustion engine. For the reduction of nitrogen oxides emitted by the internal combustion engine, it is possible, by way of the closing time setting device, for a nitrogen oxide reduction cycle to be set in which the at least one inlet valve of the internal combustion engine closes earlier or later than in the basic cycle. If the torque of the internal combustion engine falls below at least a defined torque threshold value, the internal combustion engine is operated in the basic cycle and the recirculation of the exhaust gas is enabled by way of the recirculation setting device, and wherein, if the torque of the internal combustion engine exceeds the defined torque threshold value, the internal combustion engine is operated in the nitrogen oxide reduction cycle and the recirculation of the exhaust gas is blocked by way of the recirculation setting device.

A method of operating a vehicle with a hybrid powertrain comprising an electrical drivetrain and an internal combustion engine includes detecting that a temperature of a selective catalytic reduction (SCR) device of an aftertreatment system of the vehicle is below a particular temperature; directing the electrical drivetrain to fulfil a vehicle drive load; and while the electrical drivetrain is fulfilling the vehicle drive load and the temperature of the SCR device is below the particular temperature, operating the internal combustion engine to generate airflow for transport of heat through the aftertreatment system and directing a heat source to raise a temperature through the SCR device of the aftertreatment system. The internal combustion engine can be operated in idle to spin the internal combustion engine to generate the airflow while the electrical drivetrain fulfils the vehicle drive load.

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.