An exhaust aftertreatment system for an internal combustion engine includes an outer casing defining an exhaust flow path for exhaust gases from the internal combustion engine, a selective catalytic reduction unit provided in the exhaust flow path for reducing nitrogen oxides, a urea dosing device for adding urea to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the urea with exhaust gases upstream of the selective catalytic reduction unit. The exhaust aftertreatment system further comprises an air inlet valve provided upstream of the mixer device for introducing air into the exhaust flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the exhaust flow path via the air inlet valve.

Methods and systems to control a temperature of a selective catalytic reduction catalyst are disclosed. In one example, a diverter valve that includes two butterfly valves that are coupled together via a shaft is adjusted to control a temperature at an inlet of the selective catalytic reduction catalyst so that the selective catalytic reduction catalyst may operate efficiently.

The present application provides a selective catalyst reduction system for use with a combustion gas stream of a gas turbine. The selective catalyst reduction system may include a tempering air system with a finger mixer and a number of mixer plates and a catalyst positioned downstream of the tempering air system. The tempering air system cools the combustion gas stream and evens out the temperature profile before the combustion gas stream reaches the catalyst.

The instant invention is based on techniques for using non-thermal plasma reactors in both the main exhaust pipe and in the exhaust gas recirculation feed pipe to reduce particulate matter sufficiently to meet EPA limits for PM and enhanced exhaust gas recirculation to meet NOx limits. More specifically, it is based upon the use of a non-thermal plasma device in which a high voltage charge in the plasma reactor causes extremely rapid oxidation of soot particles in the exhaust stream of an engine and further chemical reactions that aid in the reduction of NOx. The primary benefit of this technology is that it can be calibrated to optimize both soot and NOx reduction.

The instant invention is based on techniques for using non-thermal plasma reactors in both the main exhaust pipe and in the exhaust gas recirculation feed pipe to reduce particulate matter sufficiently to meet EPA limits for PM and enhanced exhaust gas recirculation to meet NOx limits. More specifically, it is based upon the use of a non-thermal plasma device in which a high voltage charge in the plasma reactor causes extremely rapid oxidation of soot particles in the exhaust stream of an engine and further chemical reactions that aid in the reduction of NOx. The primary benefit of this technology is that it can be calibrated to optimize both soot and NOx reduction.

Methods and systems are provided for controlling the temperature and ratio of gases within a gas mixing tank reservoir and selectively charging/discharging gases from the reservoir to one or both of an intake system or an exhaust system. In one example, a method (or system) may include storing exhaust gas and/or compressed intake air into a gas mixing reservoir, and increasing or decreasing flow of coolant to the reservoir based on engine operating conditions. The stored gases may be discharged to an intake system and/or an exhaust system based on requests from a controller, and coolant flow to the reservoir may be adjusted based on the composition of the gases stored within the reservoir.

An exhaust gas aftertreatment system for an internal combustion engine, which comprises an exhaust system which can be connected to the outlet of an internal combustion engine. A catalytic converter close to the engine and a second catalytic converter arranged downstream of the catalytic converter in an underbody of a motor vehicle are provided in the flow direction of an exhaust gas from the internal combustion engine flowing through an exhaust gas duct of the exhaust system. An inlet point for secondary air, an exhaust gas burner, and a fuel injector for introducing fuel into the exhaust gas duct are arranged downstream of the catalytic converter close to the engine and upstream of the second catalytic converter. According to the invention, the exhaust gas burner is activated immediately after the internal combustion engine is started in order to heat the second catalytic converter to its light-off temperature. Once the second catalytic converter has reached its light-off temperature, secondary air and fuel are additionally introduced into the exhaust gas duct and are exothermically reacted on the second catalytic converter in order to support the heating of the second catalytic converter.

An exhaust gas aftertreatment system for an internal combustion engine, which comprises an exhaust system which can be connected to the outlet of an internal combustion engine. A catalytic converter close to the engine and a second catalytic converter arranged downstream of the catalytic converter in an underbody of a motor vehicle are provided in the flow direction of an exhaust gas from the internal combustion engine flowing through an exhaust gas duct of the exhaust system. An inlet point for secondary air, an exhaust gas burner, and a fuel injector for introducing fuel into the exhaust gas duct are arranged downstream of the catalytic converter close to the engine and upstream of the second catalytic converter. According to the invention, the exhaust gas burner is activated immediately after the internal combustion engine is started in order to heat the second catalytic converter to its light-off temperature. Once the second catalytic converter has reached its light-off temperature, secondary air and fuel are additionally introduced into the exhaust gas duct and are exothermically reacted on the second catalytic converter in order to support the heating of the second catalytic converter.

A vehicle engine system includes an internal combustion engine, an air induction system configured to supply intake air to the internal combustion engine, and an evaporative emissions control (EVAP) system is configured to selectively supply purge fuel vapor to the EHC for subsequent combustion and rapid heating to a predetermined catalyst light-off temperature. The system additionally includes a booster configured to charge the intake air, and an engine bypass conduit fluidly coupled between the booster and the exhaust aftertreatment system. When the internal combustion engine is off, the booster selectively supplies a flow of intake air through the engine bypass conduit to the exhaust aftertreatment system. The flow of intake air draws purge fuel vapor from the EVAP system into the exhaust aftertreatment system.

A vehicle engine system includes an internal combustion engine, an air induction system configured to supply intake air to the internal combustion engine, and an evaporative emissions control (EVAP) system is configured to selectively supply purge fuel vapor to the EHC for subsequent combustion and rapid heating to a predetermined catalyst light-off temperature. The system additionally includes a booster configured to charge the intake air, and an engine bypass conduit fluidly coupled between the booster and the exhaust aftertreatment system. When the internal combustion engine is off, the booster selectively supplies a flow of intake air through the engine bypass conduit to the exhaust aftertreatment system. The flow of intake air draws purge fuel vapor from the EVAP system into the exhaust aftertreatment system.