Methods and systems for heating an emission control device are provided. In one example, a method for a vehicle comprises during an engine cold start, heating an emission control device of the engine using a dual heat exchanger to heat secondary air and cool exhaust gas, and further heat secondary air with an electric heater. The method further comprises directing the heated secondary air to each exhaust runner of the engine via individual air injectors to mix with exhaust gas. In this way, an improved mixture of air and exhaust reduces catalyst light-off time and increases conversion efficiency, thereby reducing hydrocarbon emissions during engine cold start.

A method of reducing noise from a high-speed, including supersonic, jet, the method includes providing the high-speed or supersonic jet in a longitudinal flow direction; and inducing a rotation of a swirl layer of the high-speed or supersonic jet around a longitudinal direction of the jet and on the jet boundary so as to promote mixing of the high-speed or supersonic jet with surrounding air.

A method of reducing noise from a high-speed, including supersonic, jet, the method includes providing the high-speed or supersonic jet in a longitudinal flow direction; and inducing a rotation of a swirl layer of the high-speed or supersonic jet around a longitudinal direction of the jet and on the jet boundary so as to promote mixing of the high-speed or supersonic jet with surrounding air.

A method for controlling a powertrain of a hybrid vehicle includes the following steps performed by a hybrid controller: determining whether an ambient air temperature is lower than a predetermined temperature; driving a motor and operating a heating disc of an electrically heated catalytic converter disposed in an exhaust pipe of an internal combustion engine during a predetermined operating time when an ambient air temperature is lower than a predetermined temperature; supplying ambient air to the heating disc; and varying a flow rate of the ambient air supplied to the heating disc in response to a temperature change of the heating disc.

Methods and systems for heating an emission control device are provided. In one example, a method for a vehicle comprises during an engine cold start, heating an emission control device of the engine using a dual heat exchanger to heat secondary air and cool exhaust gas, and further heat secondary air with an electric heater. The method further comprises directing the heated secondary air to each exhaust runner of the engine via individual air injectors to mix with exhaust gas. In this way, an improved mixture of air and exhaust reduces catalyst light-off time and increases conversion efficiency, thereby reducing hydrocarbon emissions during engine cold start.

Aspects of the present invention relate to a valve seat (20) for a poppet valve of an internal combustion engine, wherein the poppet valve comprises a head and a stem behind the head, the valve seat comprising: an aperture (21) configured to form a seal with the head of the poppet valve when the poppet valve is in a closed position; and a peripheral body (22) defining, at least in part, one or more ports (23) shaped like e.g. grooves and sized to enable injection of liquid or gas from a cylinder head of the internal combustion engine into a gas stream behind the head of the poppet valve.

A method for operating an exhaust gas burner that is situated in an exhaust gas system downstream from an internal combustion engine of a motor vehicle during a start phase of the exhaust gas burner, in which the internal combustion engine is not fired. The method includes an incremental increasing of the air mass flow supplied to the exhaust gas burner and an incremental varying of a fuel mass flow supplied to the exhaust gas burner.

An exhaust gas system is provided for a transport refrigeration unit (TRU) engine. The exhaust gas system includes an exhaust system. The exhaust system includes a catalyst operable in a temperature range to catalyze exhaust gas produced in the TRU engine and flown through the exhaust system. The exhaust gas system further includes temperature sensors respectively disposed to sense exhaust gas temperatures upstream of and downstream from the catalyst, at least one of first, second and third valves which are proportionally controllable to moderate amounts of air provided to the TRU engine, fuel provided to the TRU engine and air provided to the catalyst, respectively, and a controller. The controller is configured to compare sensed exhaust gas temperatures with the temperature range and issue a proportional signal to the at least one of the first, second and third valves in accordance with results of the comparison.

An exhaust system includes an exhaust component with a wall having an outer surface and an inner surface that defines an internal exhaust gas flow path. At least one opening is formed in the exhaust component to extend through the wall of the exhaust component from the outer surface to the inner surface. A member is formed from a resistive material and is configured to cover the at least one opening. A diverter is positioned adjacent the at least one opening to block at least a portion of the exhaust gas flow path.

An exhaust system includes an exhaust component with a wall having an outer surface and an inner surface that defines an internal exhaust gas flow path. At least one opening is formed in the exhaust component to extend through the wall of the exhaust component from the outer surface to the inner surface. A member is formed from a resistive material and is configured to cover the at least one opening. A diverter is positioned adjacent the at least one opening to block at least a portion of the exhaust gas flow path.