Abstract: An exhaust line of an internal-combustion engine contains a catalyst and a bypass pipe bypassing the catalyst. The bypass pipe can be shut-off by way of a shut-off valve. The shut-off valve has a diagnostic device for diagnosing a tightness of the shut-off valve.

Abstract: A system and a method are provided for operating an exhaust aftertreatment system of an engine in which one or more constituents of the exhaust gas are oxidized in an oxidation catalyst and one or more constituents of the exhaust gas are deoxidized by means of a group of possible chemical reactions of different type between the one or more constituents of the exhaust gas and catalytic material arranged in a selective-catalytic-reduction catalyst, wherein the exhaust gas flows from the oxidation catalyst to the selective-catalytic-reduction catalyst, wherein the steps are performed: (a) adjusting at least one desired ratio among one or more pairs of the one or more constituents by varying a space velocity of the exhaust gas in at least the oxidation catalyst; (b) varying the space velocity of the exhaust gas by varying one or more operation parameters of the engine; and (c) establishing the ratio to a value at least approaching the desired ratio among the one or more pairs of the one or more constituents at th

Abstract: Method to reduce NOx contained in an exhaust gas by including an oxidation catalyst device and a selective reduction type NOx catalyst device, which are arranged in this order from an upstream side, and a NOx purification system. Whether a volume of NO2 adsorbed in the oxidation catalyst device increases or decreases is estimated, and a flow rate of exhaust gas which bypasses the oxidation catalyst device on a basis of the increase or decrease in the estimated volume of adsorbed NO2 is controlled. This avoids incorrect supply of ammonia.

Abstract: A bypass HC-NOx system includes a NOx conversion control module that generates a signal indicating whether a close coupled catalyst is active. The system further includes a bypass valve control module that, in response to the signal, opens a bypass valve located in an active HC-NOx adsorber assembly to purge hydrocarbons from an HC adsorber, wherein the bypass valve is located upstream from the HC adsorber and a NOx adsorber. The bypass valve control module also determines a temperature of a three way catalyst and closes the bypass valve to purge nitrogen dioxide from the NOx adsorber if the temperature of the three way catalyst is greater than a predetermined temperature threshold.

Abstract: In an exemplary embodiment of the invention an exhaust gas after treatment system for an internal combustion engine comprises an exhaust gas conduit configured to transport exhaust gas from the internal combustion engine to exhaust treatment devices of the exhaust gas treatment system. A controller in signal communication with the exhaust gas aftertreatment system is configured to monitor the temperature of a selective catalytic reduction device, wherein the controller is operable to move a valve assembly to an open position when the selective catalytic reduction device is at or above an operating temperature and to move the valve assembly to a closed position when the selective catalytic reduction device is below the operating temperature for entrainment of NOx constituents from the exhaust gas.

Abstract: A safety device for an exhaust gas aftertreatment system provides an alternative exhaust route in case of high temperatures or pressures within the regenerating particulate filter of the exhaust gas aftertreatment system that may cause damage to the particulate filter. The safety device comprises a valve that redirects the flow of exhaust gas from the regenerating particulate filter when specified temperature or pressure thresholds are met or exceeded.

Abstract: An electronic control unit executing an algorithm so as to operate an exhaust purification system of an engine. The algorithm (1) commences a regeneration treatment by causing an amount of fuel supplied to a combustion process of the engine to increase so as to change an air-fuel ratio of exhaust gas of the engine from a first lean air-fuel ratio to a set rich air-fuel ratio and (2) causes uncombusted fuel to be supplied to a NOx catalyst device during at least one of: a first period in which an air-fuel ratio of the exhaust gas within the NOx catalyst device changes from the first lean air-fuel ratio to the set rich air-fuel ratio when the regeneration treatment is started; and a second period after an air-fuel ratio of the exhaust gas within the NOx catalyst device becomes a ratio indicating completion of the regeneration treatment.

Abstract: A variety of embodiments of exhaust systems for engines including small off-road engines, and related methods of operation, are disclosed. In at least some embodiments, the exhaust system includes a first conduit that receives exhaust emissions from a first engine cylinder, and a second conduit that communicates air to a first port on the first conduit. The air mixes with the exhaust emissions within the first conduit so as to produce a chemical reaction, and a level of at least one undesirable component of the exhaust emissions is reduced. Further, the exhaust system does not include any catalytic converter. In some embodiments, the exhaust system further comprises a crankcase ventilation system.

Abstract: An exhaust gas purification device 1 is equipped with a plurality of branch exhaust passages 2 and 3; a junction exhaust passage 110; a shutoff valve 4 switching between allowing and shutting off the flow of exhaust gas to the respective branch exhaust passages 2 and 3; a nitrogen oxide adsorbing material 5 temporarily adsorbing nitrogen oxides in an excess air atmosphere and detaching the adsorbed nitrogen oxides in a reducing atmosphere and reducing the nitrogen oxides in the reducing atmosphere to produce ammonia; a first combustion device 6, disposed on the exhaust upstream side of the nitrogen oxide adsorbing material 5 and having an air supply unit, changing the air supplied from the air supply unit into the reducing atmosphere; and a selective reduction catalyst 19, provided inside the junction exhaust passage 110, selectively reducing the nitrogen oxides by using ammonia as a reducing agent.

Abstract: An exhaust system for an internal combustion engine, having a first exhaust tract assigned to a first group of cylinders of the internal combustion engine, and having a second exhaust tract assigned to a second group of cylinders of the internal combustion engine, each exhaust tract comprising an exhaust gas purification device, a first silencer arranged on the outlet side of the respective exhaust gas purification device, and a second silencer arranged on the outlet side of the respective first silencer. Each exhaust tract includes a bypass line, it being possible for exhaust gas to be diverted via each bypass line, starting from the respective first silencer, bypassing the second silencers, and the bypass lines and hence the first silencers of both exhaust tracts being connected to one another by a mixing line.

Abstract: Methods and systems for treating NOx-containing exhaust from an internal combustion engine. An exhaust aftertreatment system has at least a primary oxidation catalyst, a particulate filter, and a selective reduction catalyst (SCR). A bypass line diverts a portion of the exhaust from the exhaust line from a point downstream the particulate filter to a point upstream the SCR. A secondary oxidation catalyst on the bypass line is used to generate NO or NO2 to be returned to the exhaust line upstream the SCR.

Abstract: The invention relates to an exhaust component in a gas exhaust line for gases produced by the combustion of a fuel in a heat engine. In the gas flow direction, there is a first connection to an upstream pipe carrying gases from the engine. There is also a first exhaust tube and a second exhaust tube, these two tubes being parallel and being connected to the first connection. There is a second connection to a downstream gas discharge pipe, connected to the parallel exhaust tubes. The component is characterized in that, firstly the first tube has a depolluting component, and the second tube has a silencer. The second connection is a three-way valve.

Abstract: An engine starting method is disclosed. In one example, engine operation is adjusted to reduce catalyst light off time. Exhaust temperatures may be increased until a threshold engine temperature is reached.

Abstract: The invention relates to a system and a control method for an exhaust aftertreatment system (10) of an engine (12) in which one or more constituents of the exhaust gas are oxidized in an oxidation catalyst (20) and one or more constituents of the exhaust gas are deoxidized in a selective-catalytic-reduction catalyst (70), wherein the exhaust gas flows from the oxidation catalyst (20) to the selective-catalytic-reduction catalyst (70). It is.

Abstract: Various methods and systems are provided for a system for an engine. In one example, the system includes an exhaust passage through which exhaust gas is configured to flow from the engine. The system further includes an aftertreatment system disposed in the exhaust passage, the aftertreatment system including an aftertreatment device and a bypass with a bypass control element, the bypass control element adjustable to reduce exhaust gas flow through the aftertreatment device during tunneling operation.

Abstract: Exhaust temperatures in emission control devices may be directly controlled by an intake air throttle, fuel injection timing, and exhaust pressure when an emission control device is placed between two variable geometry turbocharger exhaust turbines and coupled to a combustion engine. Such an approach may substantially raise the temperature of the exhaust aftertreatment devices in an emission control device during non-warmed exhaust conditions, leading to faster catalytic light-off.

Abstract: A method of treating emissions from an internal combustion engine of a hybrid vehicle includes directing a flow of air created by the internal combustion engine when the internal combustion engine is spinning but not being fueled through a hydrocarbon absorber to collect hydrocarbons within the flow of air. When the hydrocarbon absorber is full and unable to collect additional hydrocarbons, the flow of air is directed through an electrically heated catalyst to treat the flow of air and remove the hydrocarbons. When the hydrocarbon absorber is not full and able to collect additional hydrocarbons, the flow of air is directed through a bypass path that bypasses the electrically heated catalyst to conserve the thermal energy stored within the electrically heated catalyst.

Abstract: An apparatus is provided for a vehicle with an engine that includes an exhaust system through which exhaust gas is discharged from the engine. A heat exchanger is positioned at least partially within the exhaust system. Coolant flow passages are provided in thermal communication with the engine and with the heat exchanger. A bypass valve is operable in a first mode to direct the exhaust gas across the heat exchanger along a first flow path to transfer exhaust heat to the coolant flow passages, and is further operable in a second mode to direct at least a portion of the exhaust gas across the heat exchanger along a second flow path to transfer exhaust heat to the coolant flow passages in a second coolant heating mode. The second flow path is restricted relative to the first flow path. A method of managing exhaust heat recovery is also provided.

Abstract: An apparatus for an exhaust gas system includes a main exhaust passage, a main catalytic converter disposed in the main exhaust passage, a bypass exhaust passage, a bypass catalytic converter disposed in the bypass exhaust passage, and a valve configured to open or close a section of the main exhaust passage. The bypass exhaust passage bypasses the main exhaust passage between a branch point of the bypass exhaust passage out of the main exhaust passage and a junction with the main exhaust passage at a upstream side of the main catalytic converter. A first sensor indicates a first air-fuel ratio of exhaust gas in the bypass exhaust passage. A second sensor indicates a second air-fuel ratio of exhaust gas flowing into the main catalytic converter. A controller determines whether the valve in the closed configuration leaks exhaust gas based on the first and second air-fuel ratios of exhaust gas.

Abstract: A flammable-gas led-out pipe (5) has a terminal end portion (5a) disposed in an exhaust-gas route (7) and a metal cylinder (10) is arranged at the terminal end portion (5a) of the flammable-gas led-out pipe (5). An oxidation catalyst (8) is disposed within the metal cylinder (10). On an upstream side of the oxidation catalyst (8), an air-supply passage (12) is opened to provide an outlet (12a) and the flammable gas (4) merges with supplied air (13). The flammable gas (4) is burnt with the oxidation catalyst (8) to produce catalyst-combustion heat, which is radiated from an outer peripheral surface of the metal cylinder (10) into the exhaust gas (9) in the exhaust-gas route (7) and the exhaust gas (9) heated by this heat-radiation is mixed with the flammable gas (4) that has passed through the oxidation catalyst (8).

Abstract: Systems, methods, and computer readable storage media are described in which exhaust gas is routed to a hydrocarbon retaining device during starting, and purged to the engine intake manifold. Various alternative approaches are described for controlling operation and diagnosing degradation. Further, various interrelated configurations are described.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine is provided to desorb predetermined components contained in exhaust gas from an adsorption device for adsorbing the components and to purify the desorbed components, even during the stop of the internal combustion engine. A main exhaust passage and a bypass passage bypassing the main exhaust passage are provided. An exhaust switching valve is capable of switching a flow target into the exhaust gas flows between the main exhaust passage and the bypass passage. An adsorbent for adsorbing the predetermined components is provided in the bypass passage. An underfloor catalyst including a catalyst with a heater is provided at a downstream side of the bypass passage in the main exhaust passage. A pump and a heater are provided in an air supply passage which branches from the bypass passage at an upstream portion of the adsorbent.

Abstract: A closely-coupled exhaust aftertreatment system includes a first exhaust conduit comprising a first valve operable between a first position promoting an exhaust flow within the first exhaust conduit to an inlet of a first oxidation catalyst and a second position promoting the exhaust gas flow within a second exhaust conduit. It also includes a third exhaust conduit fluidly coupled to an outlet of the OC and comprising a second valve operable between a first position promoting an exhaust flow within the third exhaust conduit to an inlet of a particulate filter (PF) and a second position promoting the exhaust gas flow through a fourth exhaust conduit to an inlet in the second exhaust conduit. It further includes a turbocharger fluidly coupled to the second exhaust conduit downstream of the inlet and a selective catalyst reduction (SCR) catalyst that is located downstream of the turbocharger and upstream of the PF.

Abstract: A control system may include an adsorber bypass evaluation module, an adsorber bypass control module and an engine operation control module. The adsorber bypass evaluation module may evaluate a bypass closing criterion of a hydrocarbon adsorber bypass passage in an engine exhaust gas treatment device after an engine key-on condition. The adsorber bypass control module may be in communication with the adsorber bypass evaluation module and may close the hydrocarbon adsorber bypass passage after the key-on condition when the bypass closing criterion meets a predetermined condition. The engine operation control module may be in communication with the adsorber bypass control module and may start the engine after the closing.

Abstract: A diesel exhaust after-treatment system (110, 210) for a vehicle includes a precious metal primary diesel oxidation catalyst (DOC1) and a precious metal secondary diesel oxidation catalyst (DOC2). The primary diesel oxidation catalyst (DOC1) is located on an exhaust pipe (116, 250) and in fluid communication with and between an engine (12) and an exhaust gas outlet (126, 226). The secondary diesel oxidation catalyst (DOC2) is disposed in fluid communication with the primary diesel oxidation catalyst (DOC1) on a second exhaust pipe (130, 230, 232) and in fluid communication with the engine (12). At least one valve (128, 228, 246) is disposed on the exhaust pipe (116, 216) for selectively permitting the continuous, positive flow of exhaust gas through the secondary diesel oxidation catalyst (DOC2).

Abstract: An engine starting method is disclosed. In one example, engine operation is adjusted to reduce catalyst light off time. Exhaust temperatures may be increased until a threshold engine temperature is reached.

Abstract: An exhaust gas control apparatus applied to an internal combustion engine including plural cylinders and a turbocharger, wherein an exhaust passage includes first and second branch passages. The first branch passage connects exhaust sides of cylinders #1, #4 and a turbine, and includes a starter catalyst; the second branch passage connects exhaust sides of cylinders #2, #3 and the turbine, and communicates with the first branch passage upstream of the starter catalyst. The exhaust gas control apparatus includes an exhaust gas switching valve disposed at a communication part, through which the first and second branch passages are in communication, and is switchable between an introducing position at which exhaust gas is introduced into the starter catalyst from the cylinders #2, #3 and a block position at which introduction thereof is blocked. An ECU switches the exhaust gas switching valve position based on the operating condition of the internal combustion engine.

Abstract: A closely-coupled exhaust aftertreatment system for an engine having twin turbochargers includes a first exhaust conduit comprising a first valve operable between first and second positions, the first promoting flow within the first conduit to an oxidation catalyst (OC), the second promoting flow within a second conduit; a third conduit is fluidly coupled to the OC outlet and includes a second valve operable between first and second positions, the first promoting flow within the third exhaust conduit to a particulate filter (PF), the second promoting flow through a fourth conduit to an inlet in the second conduit. A first turbocharger is coupled to the second exhaust conduit downstream of the inlet; an SCR catalyst is downstream of the first turbocharger to receive the flow therefrom and upstream of the PF to provide the flow thereto. A second turbocharger is coupled to the third exhaust conduit downstream of the second valve.

Abstract: A main exhaust passage 42 and a first bypass passage 46 bypassing the main exhaust passage 42 are provided. An absorbent 52 having a function of absorbing HC components and NOx components contained in exhaust gas is provided in the first bypass passage 46. An underfloor catalyst 56 including a catalyst with an electric heater (EHC) 58 is provided in a main exhaust passage 42 on a downstream side of a downstream connecting portion 48b in a first bypass passage 46. A second bypass passage 62 that provides communication between the main exhaust passage 42 downstream of the underfloor catalyst 56 and the first bypass passage 46 upstream of the absorbent 52 is provided. A first exhaust switching valve 50 is provided in an upstream connecting portion 48a, and a second exhaust switching valve 68 is provided in a main exhaust passage side connecting portion 64a. A pump 66 is provided in the middle of the second bypass passage 62.

Abstract: A particulate matter sensor includes a first detection filter provided in an exhaust gas flow passage and capable of collecting particle matter. A second detection filter is provided on a downstream side of the first detection filter in the exhaust gas flow passage and capable of collecting the particle matter. A first differential pressure detection unit is configured to detect a first differential pressure between pressures of an upstream side and the downstream side of the first detection filter. A second differential pressure detection unit is configured to detect a second differential pressure between pressures of an upstream side and a downstream side of the second detection filter. A particle matter amount detection unit is configured to detect an amount of particle matter based on a detection result of the first differential pressure detection unit and a detection result of the second differential pressure detection unit.

Abstract: A mixing device comprises a circular disc of fin sections positioned so as to create openings in the inner and outer regions of the mixing device that generate oppositely rotating flows of exhaust gas. Each fin section may be identical, and may be created by a stamping process. The smooth surface of each fin section reduces creases, and thus, is less prone to urea buildup.

Abstract: A burner module for burning injected reformate mixed with engine exhaust in an exhaust pipe ahead of aftertreatment devices, comprising an exhaust flow divider that creates a localized region of exhaust flow for mixture of the reformate. The amount of reformate required to produce a burnable composition in the localized area is less than what is required in the prior art to provide the same composition over the entire cross-sectional region of the exhaust pipe. An igniter is provided within the localized region. Upon ignition of the reformate, the flow of reformate may be increased to the point of a stoichiometric mixture for the entire exhaust, to produce the maximum heat for warm up. The exhaust flow divider may comprise a divider tube mounted in the exhaust pipe or may be simply a protrusion from a wall of the exhaust pipe.

Abstract: One ends of an exhaust path communicate with a plurality of combustion chambers through exhaust ports, respectively, an assembling section is provided on the other ends of the exhaust path, and a turbo supercharger, an exhaust tube and an exhaust purification catalyst are connected to the assembling section, on the other hand, a bypass path communicating from the exhaust path to the exhaust tube and the exhaust purification catalyst by bypassing a turbo supercharger is provided and an exhaust control valve capable of opening and closing the bypass path is provided, and a bypass hole, which is a part of the bypass path, is provided in the cylinder head.

Abstract: A variable position catalyst includes a catalyst housing (7) accommodating a catalyst body (1) and an actuator member (9) for moving the catalyst body (1) with respect to the catalyst housing (7) such that the catalyst body (1) can be moved to an active catalyst position (35) or to an inactive catalyst position (14). The variable position catalyst is incorporated in the exhaust line of an internal combustion engine upstream of a turbocharger. The variable position catalyst can be controlled such that the catalyst body (1) is moved to the active catalyst position (35) when the engine is in a predetermined first operation state, and the catalyst body is moved to the inactive catalyst position (14) when the engine is in a predetermined second operation state.

Abstract: Systems and methods for reducing NOx emissions using a branched exhaust system with a first and second turbine including an emission-control device containing a zeolite, are described. In one example approach, a method comprises: during a first duration when exhaust temperature is below a first temperature threshold, directing exhaust gas through the second turbine and the emission-control device, and adjusting the second turbine to control intake boost; and during a second duration following the first, directing exhaust gas through the first turbine, and adjusting the first turbine to control intake boost. In this way, the first and second turbines may provide a greater degree of boost control in order to reduce boost fluctuations while enabling storing cold start NOx emissions for later reduction.

Abstract: An exhaust tract for an internal combustion engine of a motor vehicle includes a first exhaust gas line, which conducts exhaust gases from the internal combustion engine to an exhaust-gas treatment device, and a second exhaust gas line, which forms a bypass line bypassing the exhaust gas treatment device. In order to ensure sufficient treatment of the exhaust gas even in the lean operating mode of an internal combustion engine, at least one first valve and one second valve are provided in series in the bypass line. An exhaust line is provided between the first valve and the second valve to reduce the pressure between the first and second valves. The pressure upstream of the second valve and the pressure downstream of the second valve, or the ambient pressure of the motor vehicle, are determined and negative pressure is applied to the exhaust line such that an exhaust gas flow via the second valve to the outside into the environment of the motor vehicle is prevented.

Abstract: A system and method for improving emissions of an engine capable of combusting a multi-component fuel comprised of two or more fuels is presented. According to the method, the passage exhaust gases are processed in said exhaust system is determined in part from the concentration of one component fuel.

Abstract: An exhaust purification device includes a front catalyst arranged in an exhaust system of the internal combustion engine that is longitudinally mounted in a vehicle, a rear catalyst arranged in the exhaust system downstream of the front catalyst, and a bypass pipe that communicates with the exhaust passage of the exhaust system upstream of the front catalyst, communicates with the exhaust passage between the front catalyst and the rear catalyst, and is arranged at a position that is spaced apart in a direction perpendicular to the vibration direction of the exhaust system.

Abstract: An ECU executes a program including the steps of: when a switching valve is controlled to be closed, comparing exhaust gas's temperature, as detected, with a map value; if the exhaust gas's temperature is larger than the map value, determining that the switching valve normally operates; and if the exhaust gas's temperature is smaller than the map value, determining that the switching valve has abnormality.

Abstract: An air-fuel ratio control apparatus is basically provided with an exhaust system, a pair of sensors and a controller. The exhaust system includes an exhaust channel having a main catalytic converter, a bypass channel having a bypass catalytic converter, and a valve mechanism disposed in the exhaust channel to switch a pathway for exhaust gas from the exhaust channel to the bypass channel. The sensors output signals indicative of air-fuel ratios of exhaust flowing in their respective channels. The controller has first and second air-fuel ratio control sections that control an engine air-fuel ratio based on outputs of the sensors, respectively. The controller has a control mode switching section that switches control from the first air-fuel ratio control section to the second air-fuel ratio control section after a prescribed interval of time has elapsed from when the valve mechanism is switched from a closed state to an open state.

Abstract: Controlling a vehicle responsive to reductant conditions is provided. The method for controlling a vehicle having an engine with an exhaust, the exhaust having a reductant injection system including a reductant storage vessel, the engine further having a fuel system including a fuel storage vessel, may include under degraded reductant conditions, restricting vehicle motion in response to a fuel refill of the fuel storage vessel.

Abstract: A method of reducing NOx in a vehicle exhaust operating by alternating exhaust flow between two lean NOx traps and directing the emerging exhaust to a downstream SCR catalyst system. While exhaust predominantly flows through one of the lean NOx traps, a reductant is provided to the other NOx trap so as to produce ammonia that is also directed to the SCR catalyst system. An exhaust system implementing the method of the invention is also provided.

Abstract: A method for heating solid ammonia (NH3) in a main unit (12) to deliver gaseous ammonia into the exhaust gas (EG) downstream of an engine (16) includes the steps of diverting at least a portion of the exhaust gas from the exhaust gas passageway (14), fluidly communicating the exhaust gas on a delivery line (28) from the exhaust gas passageway to the main unit, heating the solid ammonia with the exhaust gas, and fluidly communicating the exhaust gas on a return line (30) from the main unit to the exhaust gas passageway.

Abstract: A method and system for managing an exhaust gas feedstream from an internal combustion engine operative lean of stoichiometry includes steps and apparatus for diverting exhaust around a three-way catalytic converter during NOx adsorber regeneration thereby increasing reductants available in the NOx adsorber to react with the adsorbed NOx.

Abstract: An exhaust gas purifying system for an internal combustion engine includes a first exhaust passage (22a) and a second exhaust passage (22b) into which an exhaust passage (21) of the internal combustion engine is bifurcated. NOx storage reduction catalysts (23a, 23b) and particulate filters (24a, 24b) are provided in each of the exhaust passages (22a, 22b). Fuel is supplied from a fuel valve (32) when NOx is to be released from the NOx storage reduction catalysts (23a, 23b). At a timing when the supplied fuel attaches to the NOx storage reduction catalysts (23a, 23b), one of exhaust control valves, for example, a first exhaust control valve (26a) is temporarily closed so as to keep the air-fuel ratio of exhaust gas rich. When NOx is released from the NOx storage reduction catalysts (23a, 23b) next time, a second exhaust control valve (26b) is temporarily closed after the fuel is supplied.

Abstract: An engine can include a first catalyst disposed in a first exhaust passage, a second catalyst disposed in a second exhaust passage to be located upstream of the first catalyst, a variable valve operating mechanism configured to make lifting amounts of a first and second exhaust valves variable between approximate zero and maximum, and a lifting amount control unit for controlling the lifting amounts of the first and second exhaust valves with the variable valve operating mechanism such that an exhaust gas amount passing through the second exhaust passage is larger than that passing through the first exhaust passage.

Abstract: The present invention provides an exhaust gas purifier capable of appropriately purifying harmful components discharged even from an internal combustion engine or a combustion instrument operated mainly in excess-air conditions. Particularly, the exhaust gas purifier is capable of appropriately removing nitrogen oxides, particulate matters including soot, etc. and in addition, capable of maintaining its purification capability without reduction.

Abstract: A process and an apparatus for treating exhaust gas from an internal combustion engine include at least two exhaust-gas treatment modules. An exhaust gas stream can be at least partly deflected depending on a load state of the internal combustion engine in such a way that at least parts of the exhaust gas flow through one or more modules. This makes it possible to advantageously construct and operate even an exhaust gas system of large-volume internal combustion engines, in which conversion and treatment of the exhaust gas is carried out in individual modules, even in no-load operation, basically at very low exhaust gas mass flow rates. The individual modules can be adapted to various load levels of the internal combustion engine. A rail-borne vehicle and a water-borne vehicle having the apparatus are also provided.

Abstract: A method is provided for compensating for factors affecting particulate matter accumulation within an aftertreatment element of an engine exhaust system. The method comprises determining rate of change of flow resistance through the aftertreatment element with time. Regeneration is periodically initiated to reduce particulate matter accumulation within the aftertreatment element. Rate of change of flow resistance through the aftertreatment element over time is correlated with at least a model of particulate matter accumulation within the aftertreatment element and a model of regeneration frequency of the aftertreatment element, based on predetermined values for particulate matter accumulation and regeneration frequency. Action, at least including increasing regeneration frequency, is initiated to compensate for an increased rate of particulate matter accumulation in the aftertreatment element.

Abstract: A system for purifying exhaust gas generated by an internal combustion engine including a bypass branching out from the exhaust pipe downstream of a catalyst and merging to the exhaust pipe, an adsorber installed in the bypass, a bypass valve member which closes the bypass, and an EGR conduit connected to the bypass at one end and connected to the air intake system for recirculating the exhaust gas to the air intake system. The bypass valve member is opened for a period after engine startup to introduce the exhaust gas such that the adsorber installed in the bypass adsorbs the unburnt HC component in the exhaust gas. The adsorber adsorbs the HC component when the exhaust temperature rises and the adsorbed component is recirculated to the air intake system through the EGR conduit. In the system, the bypass valve is provided at or close to the branching point in the exhaust pipe and a chamber is provided close to the branching point such that the conduit is connected to the bypass at the one end in the chamber.