Methods of operating an internal combustion engine that has two exhaust paths, the first path having an aftertreatment system. One method includes: operating the engine at idle; directing the exhaust flow through the first exhaust path; detecting an exhaust temperature below a predetermined temperature and/or operation of the engine at idle; and diverting all, or some, of the exhaust flow through the second exhaust path, based on the detecting. Another method includes detecting an engine condition that is indicative of an oil accumulation above a threshold and diverting the exhaust flow through the second exhaust path, based on detecting this engine condition. An exhaust subsystem that includes a controller that employs these methods is disclosed.

A system and method are disclosed for improving the performance of an aftertreatment system by elevating its temperature above an activation temperature. According to at least one aspect of the present disclosure, the method includes injecting a quantity of a fuel into certain fueled cylinders of a plurality of combustion cylinders of an internal combustion engine, the plurality of combustion cylinders further including non-fueled cylinders. Exhaust from the fueled cylinders is directed through the aftertreatment system while uncombusted gas from the non-fueled cylinders is directed away from the aftertreatment system. In certain embodiments, the uncombusted gas may be directed into an intake manifold in fluid communication with the plurality of combustion cylinders through an orifice. The system includes an engine having exhaust valves to control flow of the exhaust and uncombusted gas and a controller configured to perform the operations of the method.

A method for controlling exhaust flow in an EATS of a vehicle. A NO.sub.x sensor output parameter is monitored. It is determined that the NO.sub.x sensor output parameter is below a limit. When the NO.sub.x sensor output parameter is below the limit, it is determined that a first part of the exhaust flow should bypass at least a first area of the SCR unit and that a second part of the exhaust flow should be inputted to at least the first area of the SCR unit. It is initiated that the first part is bypassed and that the second part is inputted to at least the first area of the SCR unit. An amount of reductant that should be added to the second part of the exhaust flow is determined. Addition of the amount of reductant is initiated.

A muffler for an exhaust system of an internal combustion engine, especially for vehicles with hybrid drive, includes a muffler housing (12), a heat exchanger unit (48), arranged in the muffler housing (12), for transferring heat from combustion exhaust gas to a heat transfer medium, an inlet pipe (38), a first outlet pipe (52) and a second outlet pipe (40). A first exhaust gas flow path (54), in the muffler housing, routs exhaust gas through the heat exchanger unit (48) to the first outlet pipe (52). A second exhaust gas flow path (56), in the muffler housing, routs exhaust gas to a second outlet pipe (40), bypassing the heat exchanger unit (48). A flow path blocking/releasing device (58) for blocking and releasing at least one exhaust gas flow path (54, 56), of the first exhaust gas flow path (54) and of the second exhaust gas flow path (56).

An exhaust gas system (1) has a main flow path (2) with an exhaust gas aftertreatment device (4), and a bypass flow path (3) that has a fan (5) and a heating apparatus (6). The bypass flow path (3) has opposite ends connected to the main flow path (2) in regions upstream and downstream of the exhaust gas aftertreatment device (4). A shut-off (7) is arranged in the main flow path (2) upstream of the bypass flow path, and a further shut-off (8) is arranged in the main flow path downstream of the bypass flow path.

A cabin heating system includes a cabin air heat exchanger, an exhaust gas heat exchanger and a heat transfer loop. The heat transfer loop circulates a gaseous heat exchange fluid between the cabin air heat exchanger and the exhaust gas heat exchanger.

An exhaust-gas treatment arrangement for an exhaust system of an internal-combustion engine includes a diesel internal-combustion engine. The arrangement includes a first exhaust-gas treatment unit and, downstream of the first exhaust-gas treatment unit, an exhaust-gas treatment assembly. The first exhaust-gas treatment unit and the exhaust-gas treatment assembly are arranged axially succeeding one another in the direction of a longitudinal axis of a flow path encompassing the first exhaust-gas treatment unit and the exhaust-gas treatment assembly. A hydrocarbon-feeding assembly is provided for feeding hydrocarbon into exhaust gas flowing in the flow path. The hydrocarbon-feeding assembly includes a hydrocarbon-dispensing unit dispensing hydrocarbon into the flow path downstream of the first exhaust-gas treatment unit and upstream of the exhaust-gas treatment assembly. A swirl-flow-generating unit is provided in the flow path upstream of the hydrocarbon-dispensing unit.

An exhaust system for a motor vehicle, with an exhaust pipe for discharging exhaust of a device that produces an exhaust. A heat accumulator, which surrounds the exhaust pipe in the peripheral direction with respect to a longitudinal central axis of the exhaust pipe, is present, at least in regions thereof, and, in the radial direction between the exhaust pipe and the heat accumulator over at least a portion of the longitudinal extension the heat accumulator, a cross-section adjusting element for adjusting a passage cross section is arranged between the exhaust pipe and the heat accumulator. The cross-section adjusting element has a first holed pipe, which surrounds the exhaust pipe, and a second holed pipe, which surrounds the first holed pipe. The first holed pipe and the second holed pipe can be shifted in position relative to each other for adjusting the passage cross section.

Methods and systems are provided for operating a branched exhaust assembly in a vehicle engine in order to increase catalyst efficiency and reduce engine emissions. In one example, a method may include, during a cold-start condition, flowing exhaust first through a three-way catalyst then through an underbody converter, then through a heat exchanger and then through a turbine, each exhaust component housed on different branches on the branched exhaust assembly. After catalyst activation, exhaust may flow first through the turbine, then through the underbody converter and then through the three-way catalyst, and during high engine load, exhaust entering the turbine may be cooled in order to reduce thermal load on the turbine.

Heat recovery component for an exhaust gas system of an internal combustion engine, comprising an inlet, an outlet, a heat recovery branch conduit comprising a heat recovery branch conduit inlet, a heat recovery branch conduit outlet, and a heat exchanger arranged in the heat recovery branch conduit, a bypass branch conduit being separate from the heat recovery branch conduit, and a valve being configured to be rotatable between a heat recovery end position and a bypass end position, the valve being arranged to be rotatable around a rotation axis located in the bypass branch conduit, wherein the valve comprises a bypass valve flap and a heat recovery valve flap, the bypass valve flap and the heat recovery valve flap being operatively connected by a support.