A method for operating an exhaust gas aftertreatment system of an internal combustion engine and an exhaust gas aftertreatment system are described. The internal combustion engine has a turbine wheel, which is arranged in the exhaust gas line, of an exhaust gas turbocharger, and a bypass line which bypasses the turbine wheel and in which a three-way pre-catalytic converter is arranged. A three-way main catalytic converter is situated in the exhaust gas line. A NOx sensor is provided which measures the NOx fraction in the exhaust gas downstream of the three-way pre-catalytic converter. If the measured NOx fraction exceeds a threshold value, the three-way pre-catalytic converter is diagnosed as faulty.

A turbocharger and method of controlling the same includes a turbine housing comprising an inlet and an outlet, turbine wheel coupled to a shaft. The turbine housing comprising a first scroll and a second scroll for fluidically coupling the inlet and the turbine wheel. The first scroll has a first end adjacent the inlet and a second end adjacent the turbine wheel. The second scroll has a third end adjacent the inlet and a fourth end adjacent the turbine wheel. An exhaust gas diverter valve is coupled to the turbine housing restricting flow into the first scroll or the second scroll.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine and a non-thermal plasma generator positioned in the exhaust gas pathway. The non-thermal plasma generator is configured to increase a proportion of nitrogen dioxide in the exhaust gas. The system also includes a first treatment element positioned in the exhaust gas pathway downstream of the non-thermal plasma generator and a second treatment element positioned in the exhaust gas pathway downstream of the first treatment element. At least one of the first treatment element or the second treatment element includes a combined selective catalytic reduction and diesel particulate filter (SCR+F) element.

An engine system comprises a two stroke engine, an exhaust manifold, a tuned pipe coupled to the exhaust manifold and a turbocharger coupled to the engine. The turbocharger comprises a turbine inlet coupled to the exhaust manifold through the tuned pipe, and a turbine outlet coupled to an exhaust pipe. A silencer is coupled to the exhaust pipe. A bypass pipe has a first end coupled to the tuned pipe and a second end bypassing the turbine outlet and a wastegate disposed in the bypass pipe.

An exhaust gas heat recovery system includes a housing, a heat exchanger and a valve assembly. The valve assembly is disposed within the housing and includes a monolithic valve body, a moveable valve plate and a rotatable valve shaft. The valve body includes a bore, a valve seat surrounding the bore and trunnions integrally formed with the valve seat. The trunnions are diametrically opposed to each other and laterally extending outside of the housing. The valve plate coupled for rotation with the valve shaft between a first position allowing exhaust gas flow through the bore and the first exhaust gas passageway, and a second position allowing exhaust gas flow through the second exhaust gas passageway and preventing exhaust gas flow through the bore and the first exhaust gas passageway. The valve shaft being supported for rotation by the trunnions.

The present invention relates to a heat recovery system comprising a device which allows the connection between the elements of said system, such as a heat exchanger and an actuator controlling a valve of the present system. Said actuator is in turn configured such that its operation depends on the behavior of a substance due to the action of the temperature of a fluid, for example the liquid coolant used in the heat exchanger of the system, which is arranged in an exhaust duct of an internal combustion engine.

Additionally, the invention also relates to a method of assembly of a system having these features.

An exhaust after-treatment system that is configured to treat an exhaust produced by an engine, and includes a bypass passage including an inlet for receiving an amount of the exhaust from an exhaust passage. A first exhaust treatment component is located within the bypass passage, and a valve is located proximate the bypass passage that is configured to control the amount of the exhaust that enters the inlet of the bypass passage. A second exhaust treatment component is located in the exhaust passage downstream from the inlet of the bypass passage, wherein an outlet of the bypass passage communicates the exhaust treated by the first exhaust treatment component back to the exhaust passage at a location that is downstream from the second exhaust treatment component such that the exhaust treated by the first exhaust treatment component does not interact with the second exhaust treatment component.

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.

Embodiments of emission reduction system including various embodiments of an emission filters for a power plant including a gas turbine are disclosed. The system includes: an emission filter; and a retraction system operably coupled to an exhaust passage of the gas turbine. The exhaust passage defines an exhaust path of exhaust from the gas turbine. The retraction system selectively moves the emission filter between a first location within the exhaust path and a second location out of the exhaust path. In a combined cycle power plant, the first location is upstream of a heat recovery steam generator (HRSG). The systems and filters described allow for temporary positioning of emission filter(s) just downstream of a gas turbine exhaust outlet, or upstream of an HRSG, where provided, for emission reduction at low loads or startup conditions, and removal of the emission filter(s) once operations move to higher loads.

A heater system for an exhaust system is provided. The heater system includes a heater disposed in an exhaust conduit. The heater includes a plurality of heating elements disposed in the exhaust conduit. A heating control module controls the plurality of heating elements differently according to operating conditions specific to each heating element. In other forms, the heater system for an exhaust system has a plurality of heating zones, instead of a plurality of heating elements. The heating control module controls the plurality of heating zones differently according to operating conditions specific to each heating zone.