Abstract: An internal combustion engine in an engine exhaust passage of which an NOx adsorption catalyst (12) adsorbing NOx contained in exhaust gas at the time of a low temperature and desorbing the adsorbed NOx when the temperature rises and an NOx storage catalyst (14) are arranged. When the NOx storage catalyst (14) can store NOx, the temperature of the NOx adsorption catalyst (12) is made to forcibly rise to a target temperature at which the amount of NOx which the NOx storage catalyst (14) can store is desorbed, and the NOx desorbed from the NOx adsorption catalyst (12) is stored in the NOx storage catalyst (14).

Abstract: Art is provided for an exhaust purification system for an internal combustion engine, which decreases an amount of exhaust flowing to a storage-reduction type NOx catalyst and supplies a reducer to the NOx catalyst so as to reduce NOx stored in the NOx catalyst, wherein the manner in which the reducer is dispersed in the NOx catalyst can be controlled to achieve more reliable execution of a NOx reduction treatment. Air-fuel ratio detecting unit is disposed upstream and downstream of the storage-reduction type NOx catalyst. During a predetermined period subsequent to decreasing an amount of exhaust flowing to the NOx catalyst and adding the reducer to the exhaust, a reducer-adding timing is changed such that a difference between an air-fuel ratio detected by the air-fuel ratio detecting unit disposed upstream of the NOx catalyst and an air-fuel ratio detected by the air-fuel ratio detecting unit disposed downstream of the NOx catalyst becomes a predetermined target value.

Abstract: An exhaust gas emissions reactor and method of treating exhaust gas. The reactor has a housing for receiving exhaust gas from an engine. An oxidation catalyst is disposed in the housing for receiving exhaust gas from an inlet, and at least one mixing duct in the housing receives exhaust gas from the oxidation catalyst. An injector introduces reduction agent into the exhaust gas in the mixing duct, and at least one mixer effects mixing of exhaust gas and reduction agent. Disposed in the mixing duct downstream of the injector is an SCR catalyst for receiving exhaust gas/reduction agent mixture therethrough. Treated exhaust gas is conveyed to an outlet of the housing.

Abstract: An exhaust gas control apparatus for an internal combustion engine includes an exhaust gas purification catalyst device provided in an exhaust passage for the engine; an HC adsorption portion, provided in the exhaust passage, which adsorbs hydrocarbon in exhaust gas; a passage switching portion that selectively closes/opens a second passage bypassing the HC adsorption portion using an intake pipe negative pressure in the engine so that the exhaust gas flows in a first passage provided with the HC adsorption portion, or in the first passage and the second passage; and a control portion that controls the negative pressure so that the second passage is closed, when a predetermined condition is satisfied at the time of start of the engine. The control portion executes at least one of a control that advances the valve timing of an intake valve, and a control that reduces the opening amount of a throttle valve.

Abstract: An exhaust gas pressure P, exhaust gas temperatures TU and TD on upstream and downstream of a DPF, a rotation speed Ne, a load Q, and an intake flow rate F as various operating conditions are read, and an amount of PM generated for short time ?t is obtained to be added to a PM deposited amount m, and thus, to obtain an initial deposited amount. Exhaust gas properties and a space velocity SV are obtained based on various operating conditions, and the PM deposited amount m after a lapse of the short time ?t is estimated from a PM deposited amount estimation equation “m=m·exp(?B·?t)” having been derived considering the exhaust gas properties and the space velocity SV. When the PM deposited amount m is equal to or more than a predetermined value, a forced regeneration processing in the DPF is executed, and thereafter, the PM deposited amount m is reset to 0.

Abstract: One aspect of the invention relates to a power generation system that has an internal combustion engine that operates in a low temperature combustion mode to produce an engine exhaust that is low in NOx and particulate matter. The exhaust is treated by a fuel cell to remove organic compounds and CO while producing useful power. Another aspect of the invention relates to controlling the adiabatic flame temperature by EGR drawing from upstream of the fuel cell. A further aspect of the invention relates to treating engine exhaust with a reducing catalyst and then with a fuel cell. A still further aspect of the invention relates to treating exhaust with an intermediate temperature solid oxide fuel cell. A further aspect of the invention relates to a system equipped with a valve allowing exhaust to selectively bypass a fuel cell.

Abstract: An exhaust bypass valve assembly for an internal combustion engine includes an exhaust bypass valve having valve structure coupled to a rotatable shaft such that rotation of the shaft moves the valve structure between opened and closed positions. An actuator is disposed remotely from the bypass valve for selectively causing rotation of the shaft associated with the valve structure in opposing directions. Linkage structure is connected between the actuator and the shaft to transfer motion of actuator to the shaft.

Abstract: Various systems and methods are described for controlling a NOx sensor coupled to an engine exhaust system in a motor vehicle. One example method comprises generating an offset of the sensor based on an ambient air flow drawn into the exhaust system, the ambient air flow having circumvented cylinders of the engine, and adjusting an output of the sensor based on the generated offset.

Abstract: An apparatus, system, and method are disclosed for enhancing the efficiency of an exhaust aftertreatment application. The method may include determining the current operating conditions of the application, the optimal operating conditions of a target component, and the performance criteria of a conditioning component relative to the optimal operating conditions. The method may include determining an optimal fraction of an exhaust flow to pass through the conditioning component to achieve the optimal operating conditions of the target component. The method may further include manipulating a bypass valve position based on the optimal fraction of exhaust flow to pass through the conditioning component. The target component may be a selective catalyst reduction (SCR) component that operates optimally at a designed NO2/NOx mole ratio. The conditioning component may be a diesel oxidation catalyst (DOC) that affects the NO2/NOx mole ratio.

Abstract: Systems and methods for abating NOx emission in an exhaust stream are provided. Systems comprising hydrocarbon conversion over a partial oxidation catalyst in a slip stream and a hydrocarbon selective catalytic reduction catalyst are described. The emissions treatment system is advantageously used for the treatment of exhaust streams from lean burn engines including diesel engines, lean burn gasoline engines and locomotive engines.

Abstract: An exhaust-treatment system is provided having an oxidation catalyst configured to heat exhaust gas flowing through the oxidation catalyst. The system also has a particulate filter configured to receive the heated exhaust gas, and a recirculation loop configured to receive a portion of heated exhaust gas downstream of the oxidation catalyst and deliver the portion of exhaust gas upstream of the oxidation catalyst.

Abstract: A control apparatus for an internal combustion engine, which can generate exhaust pressure pulsation at an early period while suppressing the degradation of volumetric efficiency, when a request to enhance the exhaust pressure pulsation is made in the internal combustion engine which includes a variable valve mechanism that makes variable a valve overlap period, and a variable nozzle type turbocharger.

Abstract: Exhaust gas apparatus for the cleaning of exhaust gas where the exhaust gas apparatus comprises an exhaust conduit section which is formed with at least two separate flow paths. Each flow path is provided with a particle filter for the removal of particulate matter from the exhaust gas, an NOx trap for the removal of NOx from the exhaust gas. The exhaust gas apparatus further comprises at least one cold flame vaporizer in which fuel is partially oxidized in preheated air to form a cold flame gas where the cold flame vaporizer is arranged in fluid communication with each of the flow paths in the exhaust conduit section such that the cold flame gas can flow through the particle filter and the NOx trap, and valve means for controlling the flow of cold flame gas from the cold flame vaporizer to each flow path in the exhaust conduit section. Thereby, both the particle filter and the NOx trap in at least one of the flow paths can be regenerated in a single operation.

Abstract: There are provided a control device and a control method for an exhaust gas purification apparatus that can prevent the actual adsorption amount from becoming excessively lower than the saturated adsorption amount and can prevent the reduction efficiency of the reduction catalyst from degrading even when the temperature of catalyst continues to shift to a low temperature side for a predetermined time or longer.

Abstract: According to one representative embodiment, an apparatus for controlling reductant dosing in an SCR catalyst system having a reductant injection system configured to inject reductant into an exhaust gas stream includes a controller, an actual reductant dosing rate module, and a reductant doser compensation module. The controller is configured to determine a reductant dosing rate command representing a desired reductant dosing rate. The actual reductant dosing rate module is configured to determine a predicted actual reductant dosing rate based at least partially on the reductant dosing rate command. The reductant doser compensation module is configured to determine a modified reductant dosing rate command based at least partially on the predicted actual reductant dosing rate. The reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.

Abstract: A method for remediating a NOx-containing lean diesel emission includes providing a LNT/SCR catalyst system including a SCR catalyst and a first and second LNT. The SCR catalyst is disposed downstream of the second LNT which is disposed downstream of the first LNT. The lean NOx-containing diesel emission is introduced to the first LNT with the NOx being absorbed on to the first LNT forming a substantially NOx-free lean diesel emission. An exotherm generating agent is introduced to the substantially NOx-free diesel emission between the first LNT and the second LNT to form a reactive lean diesel emission. The reactive lean diesel emission is introduced to the second LNT generating a quantity of heat effective for desorbing absorbed NOx. A reducing agent is introduced into the desorbed NOx between the second LNT and SCR catalyst. The desorbed NOx diesel emission is remediated in the SCR catalyst.

Abstract: A system for venting crankcase emissions from an engine is disclosed generally comprising a crankcase emissions conduit that communicates blow-by gases from the crankcase into the exhaust flow of an exhaust conduit, which includes a venturi, via an inlet located upstream of the minimum inner diameter of the venturi in order to pump the crankcase emissions therethrough. In certain embodiments, the gases are then directed to a filter assembly, which may include a particulate filter and may include a catalyst for facilitating redox of harmful substances to create harmless compounds prior to venting them or recirculating them in the system. In certain advantageous embodiments, an auxiliary oxygen supply is provided to facilitate these burning processes.

Abstract: An exhaust system for a motor vehicle engine includes mixing vent flaps in the exhaust pipe which open responsive to exhaust temperature. The vent flap forms a portion of the exhaust pipe when closed and is pivotally attached along one edge to the exhaust pipe to open inwardly into the exhaust pipe to constrict and accelerate flow in the pipe to allow outside air to be drawn into the exhaust pipe. A magnetic catch latches the vent flap in its closed position and a magnetic release responsive to increased temperature of the exhaust stream releases the vent flap.

Abstract: An internal combustion engine includes a main enlarged member extended towards a camshaft for forming reed valve chambers. The main enlarged member is integrally provided on a head cover of the engine at a location at which reed valves for controlling supply of secondary air to an exhaust system are disposed. The main enlarged member is extended towards the camshaft for increasing volume of the reed valve chambers while avoiding the increase in size of the head cover. A recessed portion is provided on a cam cap fastened to a cylinder head of the engine. A portion of the main enlarged member is inserted into the recessed portion such that cam cap cooperates with the cylinder head for rotatably supporting the camshaft.

Abstract: Methods and systems for detecting faults with nitrogen oxides sensors used to detect the presence of nitrogen oxides in an exhaust effluent gas stream emitted from a combustion engine during its operation include providing a virtual nitrogen oxides sensor measurement compared with actual nitrogen oxides content measured by nitrogen oxides sensors.

Abstract: A method for controlling an SCR-exhaust gas after-treatment system (1) of an internal combustion engine (8), in particular of an internal combustion engine of a motor vehicle, has one or more steps for determining the quality of the reducing means.

Abstract: A catalyst warm-up control is carried out in a state with a first exhaust valve closed and a second exhaust valve opened. After completion of the catalyst warm-up, if there is an acceleration request, exhaust gas temperature is acquired. If the exhaust gas temperature is equal to or lower than a predetermined value, the second exhaust valve is opened to an intermediate lift to thereby prevent an abrupt drop in exhaust gas temperature. If the exhaust gas temperature is higher than the predetermined value, the second exhaust valve is fully closed to thereby introduce the whole amount of exhaust gas to a turbine. A vehicle control device that achieves both prevention of catalyst deactivation and acceleration performance enhancement can be thus provided.

Abstract: A method of operating an engine system comprising operating a first cylinder group at a first number of strokes per combustion cycle, operating a second cylinder group at a second number of strokes per combustion cycle, the second number of strokes per cycle being different than the first number of strokes per cycle.

Abstract: Methods for determining when to regenerate an exhaust gas particulate filter (10), for regenerating, and for calibrating a pressure drop across such filters are disclosed. An example method involves reducing a first amount of particulates (52) accumulated in the filter to a residual amount RADP. The method also includes measuring the residual amount RADP by exciting the microwave resonant cavity (126) in which the filter resides with microwave radiation (182) and then monitoring the microwave cavity response. The method also includes using the measured value of RADP to calibrate a pressure drop threshold ?PTH SO that it is representative of a limit (TDP) of particulate accumulation in the filter. The methods may also include regenerating the filter a number of times and each time re-setting the pressure drop threshold ?PTH based on measurements of RADP taken after each filter regeneration.

Abstract: Method for controlling an injector intended for injecting a pollution-control liquid additive into the exhaust gases of an internal combustion engine at a flow rate governed by a given frequency and opening time of the injector, the injector having a calibration curve that establishes, at given frequency, pressure, temperature and nature of the liquid, the amount of liquid injected during an opening of the injector as a function of the duration of this opening, this curve comprising at least one linear zone (calibration line) and a non-linear zone, said method being characterized in that in the linear zone the parameters of the calibration line are used and in the non-linear zone use is made of a set opening time and a variable frequency according to at least one calibration point established for this purpose. SCR system to which this method can be applied.

Abstract: The invention concerns a system for evaluation regeneration of pollution management means (1) integrated in an exhaust line (2) of a motor vehicle engine, characterized in that it comprises means (4) for determining the thermal power input by the exhaust gas upstream of the pollution management means during the regeneration phase thereof and means (4) for comparing said power to threshold values (Sb, Sh) to determine a partial or total failure of regenerating said means.

Abstract: The exhaust gas temperature control method includes executing an exhaust gas temperature control to raise an exhaust gas temperature upon determining that a purificatory performance of an exhaust gas purification device of an engine has declined. The step of executing of the exhaust gas temperature control includes performing a first fuel injection control in which a timing of a main fuel injection is retarded and a post fuel injection is executed after the main fuel injection when the internal combustion engine is operating in the first operating region, and performing a second fuel injection control in which the timing of the main fuel injection is retarded and an execution of the post fuel injection after the main fuel injection is prohibited when the internal combustion engine is operating in the second operating region.

Abstract: A method and system for monitoring operation of an exhaust treatment system of a diesel engine includes a dosing system for injecting an injection fluid and a temperature sensor generating temperature signals corresponding to exhaust temperatures. A control module determines a temperature change after an injection of injection fluid based on the temperature signals, compares the temperature change to a threshold, and generates a fault signal in response thereto.

Abstract: An exhaust gas purifying system includes: a NOx trapping agent (2) which adsorbs nitrogen oxide when an excess air ratio of exhaust gas is more than 1, and releases nitrogen oxide when the excess air ratio is 1 or less; a NOx purifying catalyst (13) which reduces nitrogen oxide to nitrogen; and an oxygen concentration controller which controls oxygen concentration in the exhaust gas. When the excess air ratio of the exhaust gas is more than 1, nitrogen oxide is adsorbed to the NOx trapping agent (2). When the excess air ratio of the exhaust gas is 1 or less, the oxygen concentration controller controls the oxygen concentration of the exhaust gas at an inlet of the NOx purifying catalyst between 0.8 and 1.5% by volume, so that the NOx purifying catalyst reduces nitrogen oxide released from the NOx trapping agent.

Abstract: A diesel engine is provided with an exhaust fuel addition valve capable of adding fuel from an exhaust passage on an upstream side of an exhaust post-treatment device. An ECU, which is a control unit of the diesel engine, has a function to estimate biofuel concentration in the fuel and a function to obtain an exhaust temperature in the exhaust passage. The ECU sets a minimum operating exhaust temperature, which is a lower limit value of the exhaust temperature to permit operation of the exhaust fuel addition valve, according to the estimated biofuel concentration. The fuel added from the exhaust fuel addition valve is sufficiently vaporized in exhaust gas having temperature not lower than a minimum operation permission exhaust temperature set according to the biofuel concentration and is allowed to flow to the exhaust post-treatment device.

Abstract: The invention relates to a system for managing a reagent dispensing device in the exhaust line of an engine, said circuit including a tank (1), an injection means (3), a means for conditioning the reagent, sensors capable of determining the representative parameters of the condition of the dispensing circuit and of the reagent, and actuators for controlling the conditioning and injection means driven by a calculation unit based on the condition of the dispensing circuit and of the reagent and on the engine parameters determined by an engine control unit (5) characterised in that the calculation unit is integrated in the engine control unit (5) and in that the system includes an analog/digital interface (4) for processing the analog signals from the sensors (2) and the actuators (3, 7, 8, 9), provided in the vicinity of the tank (1) and connected to the engine control unit by a multiplexed digital link.

Abstract: A method of removing sulfur from a filter system of an engine includes continuously passing an exhaust flow through a desulfation leg of the filter system during desulfation. The method also includes sensing at least one characteristic of the exhaust flow and modifying a flow rate of the exhaust flow during desulfation in response to the sensing.

Abstract: A method and system for controlling a diesel particulate filter includes a particulate matter load determination module determining a particulate matter load in a diesel particulate filter (DPF), a desired oxygen level determination module determining a desired exhaust gas oxygen level based on the particulate matter load, an oxygen comparison module comparing the desired exhaust gas oxygen level and a measured exhaust gas oxygen level and generating a comparison signal and an electric DPF control module controlling an electrically heated catalyst in response to the comparison signal.

Abstract: An exhaust system for use with a diesel engine includes a diesel particulate filter configured to capture particulate matter exhausted from the diesel engine, a first sensor operable to detect a particulate matter accumulation level within the diesel particulate filter, and a second sensor operable to detect an ambient temperature of an environment surrounding the diesel particulate filter. The exhaust system also includes a control module electrically coupled to the first sensor, the second sensor, and the diesel particulate filter. The control module is operable to adjust a first regeneration threshold based on the detected ambient temperature. The control module is also operable to initiate regeneration of the diesel particulate filter when the detected particulate matter accumulation level reaches the first regeneration threshold.

Abstract: An object of the present invention is to prevent an excessive temperature rise of a precatalyst in the case where the precatalyst is provided in the exhaust passage upstream of an exhaust gas purification apparatus and has a heat capacity smaller than that of the exhaust gas purification apparatus, and reducing agent is added from a reducing agent addition valve toward an upstream end surface of the precatalyst. According to the present invention, the reducing agent addition valve is located in such a way that the reducing agent added through it reaches the precatalyst in a liquid state.

Abstract: To provide an exhaust emission control device of an internal combustion engine able to well atomize a reducing agent and ensure supply of combustion air. Since a controller of the exhaust emission control device also controls a nozzle opening degree of a variable geometry turbocharger for purpose of spraying a urea water, even in the state where the engine works in a low load range of T1 to T2 where supercharging pressure normally can not be increased, supercharging pressure P suitable to atomization of the urea water can be obtained by controlling the nozzle opening degree of the variable geometry turbocharger to be closer to a closing side compared to the conventional art (shown by the chain double-dashed line), while the urea water can be securely atomized by a part of the supercharged air.

Abstract: A method of controlling engine NOx production is provided. The method may include determining a desired amount of NOx production for at least one engine cylinder at a first time and determining at least one engine operating parameter to produce the desired amount of NOx using a feed-forward neural network.

Abstract: A method of affecting soot particulate size in an internal combustion engine exhaust by selectively providing a phosphorous based additive to the engine during combustion. Soot particulate size can be increased or decreased depending on the particular additive provided. Also disclosed in a conditioning effect experienced by using a phosphorous based additive for a period of time. A conditioned engine can also have its exhaust properties affected during the life of its conditioned state. Manipulating particle size during engine operation can employ an oligomeric phosphorous compound. Engine conditioning can employ a monomeric phosphorous containing compound, an oligomeric phosphorous containing compound, a polymeric phosphorous containing compound, or combinations thereof.

Abstract: An air-fuel ratio control apparatus of an internal combustion engine includes: an exhaust gas purifying catalyst disposed in an exhaust passage of the internal combustion engine; fuel cutting means for cutting fuel to be supplied to the internal combustion engine at the time of deceleration of the internal combustion engine; and catalyst degradation suppressing means for suppressing degradation of the exhaust gas purifying catalyst by prohibiting operation of the fuel cutting means when it is determined that the degradation of the exhaust gas purifying catalyst advances, wherein the catalyst degradation suppressing means sets an operation permitting period, during which the operation of the fuel cutting means is permitted after completion of a fuel quantity increasing operation of the internal combustion engine.

Abstract: A control device for a truck dump body heating system includes a valve for controlling an exhaust gas flow to either an exhaust stack or an inlet to the dump body heating conduit. The valve may be manually controlled by the operator to select between the exhaust and heating functions. An override detects whether a diesel particulate filter regeneration is being performed, and responsive thereto, causes the valve to direct exhaust gas to the stack, preventing excessive heating of the dump body.

Abstract: An exhaust gas passageway of an internal combustion engine is basically provided with a main exhaust passageway, a bypass exhaust passageway, a bypass catalytic converter provided in the bypass exhaust passageway, a bypass control valve, an upstream air-fuel ratio sensor and a downstream air-fuel ratio sensor. The bypass exhaust passageway bypasses a portion of the main exhaust passageway between an upstream junction and a downstream junction. The bypass control valve opens or closes a portion of the main exhaust passageway. The upstream air-fuel ratio sensor is disposed upstream of the bypass catalytic converter to sense air-fuel ratio of an exhaust gas flowing into the bypass catalytic converter. The downstream air-fuel ratio sensor is disposed downstream of the bypass catalytic converter to sense air-fuel ratio of the exhaust gas flowing out of the bypass catalytic converter.

Abstract: In a region where the engine load is less than a first predetermined value, only a second exhaust valve that opens and closes a second exhaust passageway that bypasses a turbine of a supercharger is opened. In a region where the engine load is greater than or equal to the first predetermined value and less than a second predetermined value, both the second exhaust valve and a first exhaust valve that opens and closes a first exhaust passageway that leads to the turbine are opened. In a region where the engine load is greater than or equal to the second predetermined value, only the first exhaust valve is opened. A predetermined value for the time of lean combustion is set lower than a predetermined value for the time of stoichiometric combustion.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine includes plural exhaust gas purifying units which are provided on exhaust gas passages connected to plural cylinder groups in the internal combustion engine and purify exhaust gas flowing in the exhaust gas passages, a regeneration determining unit which determines whether or not the plural exhaust gas purifying units should be regenerated, and a regeneration control unit which executes regeneration control for regenerating the exhaust gas purifying units when the regeneration determining unit determines that the exhaust gas purifying units should be regenerated. The regeneration control unit simultaneously executes the regeneration control for the plural exhaust gas purifying units when a change of a combustion mode of the internal combustion engine is involved before and after execution of the regeneration control.

Abstract: A system for providing heat to the dump body of a dump truck is disclosed. The disclosed system is suitable for use with truck equipped with a diesel particulate filter. When enabled, the system controls the exit path of exhaust gas such that it is routed to the dump body during normal operating conditions. In one embodiment, when the diesel particulate filter enters a regeneration cycle, high heat is produced. The system then routes the exhaust gas as to bypass the dump body to avoid heat damage from the higher temperature exhaust gas.

Abstract: A catalyst system that may regenerate while removing pollutants from an exhaust gas of an engine. The system may have a converter with multiple segments of chambers. At least one of the chambers may be regenerated while the remaining chambers are removing pollutants from the exhaust. The chambers may be rotated in turn for one-at-a-time regeneration. More than one chamber may be regenerated at a time to remove collected pollutants. The system may have plumbing and valves, and possibly mechanical movement of the chambers, within the system to effect the changing of a chamber for regeneration. The chambers connected to the exhaust may be in series or parallel. A particulate matter filter may be connected to the system, and it also may be regenerated to remove collected matter.

Abstract: An exhaust emission purifying apparatus for an engine in which it is determined that a reducing agent supply system is clogged, which is arranged on the downstream of a pump carrying out suction and pumping of a liquid reducing agent out of a reducing agent tank, when a reduction in a pressure of the liquid reducing agent remaining in the downstream of the pump and also in the upstream of a flow control valve by an amount equal to or more than a first predetermined pressure does not occur until a cumulative injection amount obtained by sequentially integrating an injection amount of the liquid reducing agent computed in real time based on engine operating conditions reaches a predetermined amount after the pump has been temporarily stopped.

Abstract: A reducing agent addition valve is arranged in a position in which at least part of a reducing agent added to an exhaust gas in an exhaust passage at a location upstream of a precatalyst reaches the precatalyst in the state of liquid, and the reducing agent is supplied in a more suitable state to an exhaust gas purification device which is arranged in the exhaust passage at a downstream side of the precatalyst. When the addition of the reducing agent is performed by the reducing agent addition valve, the flow rate of the exhaust gas flowing into the precatalyst is decreased so that at least part of the reducing agent, which has reached the precatalyst and has vaporized in the precatalyst, is caused to flow back.

Abstract: The present invention provides a technology enabling regeneration of the purification performance of an exhaust purification device more reliably and more efficiently in an exhaust purification system combining a plurality of branch passages bifurcating from an exhaust passage and an exhaust purification device provided in each branch passage. When regenerating the purification performance of a first exhaust purification device provided in a first branch passage, a second valve provided in a second branch passage is set at a predetermined first intermediate opening and a first valve provided in the first branch passage is fully closed. Fuel is then added from a first fuel addition valve provided in the first branch passage.

Abstract: A device for use in an exhaust aftertreatment system for an internal combustion engine is provided. The device comprises a particulate filter system having a particulate filter (DPF) for the collection of particles from the engine and a heating unit for the intermittent burning of soot at a temperature suitable for soot combustion. The particulate filter system is arranged to switch between an operating mode for the collection of soot and an operating mode for active regeneration. A bypass line extends between the inlet and outlet of the particulate filter system. A valve disposed in the bypass line allows opening or closing of an exhaust gas flow through the bypass line, in dependence on the operating mode of the particulate filter system, by a control member.

Abstract: A diesel engine exhaust treatment system has both a NOx reduction device and a diesel particulate filter. The system is designed to ensure that the NOx reduction device operates within its optimal temperature conditions. Using exhaust flow control valves, the exhaust flow can be directed into either the NOx reduction device first or into the diesel particulate filter first, and then into the other device, before exiting out the tailpipe.