Provided is an exhaust gas purifying apparatus including a first catalyst and a second catalyst that passes exhaust gas from the first catalyst, in which the temperature of the second catalyst can be increased in an early stage after an engine is started, and thus exhaust gas purification efficiency can be enhanced in an earlier stage than in conventional apparatuses. The apparatus includes an exhaust gas purifying catalyst that includes a first catalyst for purifying exhaust gas from an exhaust manifold and a second catalyst for purifying exhaust gas having passed through the first catalyst. The heat capacity of the first catalyst is lower than that of the second catalyst. The heat capacity of the second catalyst is 184 to 322 J/K under a temperature environment of 25 C., and that of the first catalyst is less than or equal to 20 J/K under a temperature environment of 25 C.

A damper assembly for minimizing heat loss through an exhaust stack includes a housing mountable within the stack and an umbrella received within the housing. The umbrella is selectively movable between a first position in which the umbrella is received within the housing, and second position in which the umbrella is extended from the housing such that a peripheral edge of the umbrella is in close association with an interior sidewall of the exhaust stack to minimize a flow of fluid past the umbrella and out of the stack.

There is provided an exhaust-gas aftertreatment arrangement for an internal combustion engine comprising a first catalytic converter, a second catalytic converter arranged in parallel with the first catalytic converter, the first and second catalytic converters being arranged to receive exhaust gas from an engine, a connection pipe fluidly connecting an outlet of the second catalytic converter with an inlet of the first catalytic converter, thereby allowing a flow of exhaust gas through the connection pipe, and an outlet valve arranged in the outlet of the second catalytic converter and downstream of the location of the connection pipe, wherein the outlet valve is configured to control a flow of exhaust gas through the second catalytic converter. There is also provided a method for controlling an exhaust-gas aftertreatment arrangement.

Methods and systems are provided for improving combustion events during cold-starts of a vehicle engine, where the cold-start events include start/stop events. In one example, a method comprises spinning the engine in a reverse direction in response to an engine pull-down event where a temperature of an intake manifold of the engine is below a threshold, to heat the intake manifold by drawing exhaust system heat to the intake manifold. In this way, combustion may be improved in response to requests to start the engine, which may reduce undesired emissions and which may improve fuel economy.

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.

The deterioration of an exhaust gas purification catalyst is suppressed as ranch as possible. An exhaust gas purification system for an internal combustion engine comprising: a throttle valve; a turbocharger; an exhaust gas purification catalyst; a bypass passage; a turbo bypass valve (TBV); and a controller. The controller is configured to carry out fuel out processing and deterioration suppression control. In the deterioration suppression control, when a temperature of the exhaust gas purification catalyst is equal to or higher than a predetermined temperature in the course of the execution of the fuel cut processing, the degree of opening of the TBV becomes smaller, and the degree of opening of the throttle valve becomes larger, than when the temperature of the exhaust gas purification catalyst is lower than the predetermined temperature in the course of the execution of the fuel cut processing.

The heat insulation structure for a component of an exhaust system of a piston engine is arrangeable around the component such that an air space is formed between the component and the heat insulation structure, and includes an outer shell layer a middle shell layer that is arranged inside the outer shell layer, and a first inner shell layer that is arranged inside the middle shell layer. A first air gap is arranged between the outer shell layer and the middle shell layer, a first insulation layer is arranged between the middle shell layer and the first inner shell layer, and the outer shell layer is provided with venting apertures for natural ventilation of the first air gap.

An engine device that includes the first case that removes particulate matter in the exhaust gas of the engine and the second case that removes nitride oxides in the exhaust gas of the engine and that connects the second case to the first case via a urea mixing pipe, an upper surface cover body is adhered on the upper portion of the engine via supporting leg bodies, and the upper portion of the engine is covered with the upper surface cover body, while any one or both of the first case and the second case are placed on the upper surface side of the upper surface cover body.

Methods and systems are provided for operating an engine exhaust aftertreatment system to increase the efficiency of an exhaust underbody catalyst and reduce engine emissions. In one example, a bypass passage may be coupled to a main exhaust passage and during conditions which may adversely affect functionality of the underbody catalyst, exhaust may be opportunistically routed via the bypass passage avoiding the underbody catalyst. Exhaust heat may be recovered via a heat exchanger coupled to the bypass passage, and the heat may be used for engine heating, and passenger cabin heating.

An exhaust heat recovery device including a heat exchange portion, an exhaust branch portion, and an exhaust distribution portion, wherein the heat exchange portion comprises a pillar-shaped honeycomb body having a first end face and a second end face, and a casing accommodating the honeycomb body, the exhaust branch portion has a branch path that branches a path of exhaust gas flowing into the honeycomb body into a central portion and an outer circumferential portion in a cross-section orthogonal to an axial direction of the honeycomb body, and the exhaust distribution portion has an exhaust distribution mechanism that adjusts a heat recovery amount by changing an airflow resistance of the path of the exhaust gas in the central portion of the honeycomb body and varying the exhaust amount passing through the path of the exhaust gas in the outer circumferential portion of the honeycomb body.