Abstract: The present application generally relates to a diesel engine and, more particularly, to a control system and method for an exhaust aftertreatment system for a locomotive diesel engine. In accordance with an embodiment of the present system, a two-stroke uniflow scavenged diesel engine system including an exhaust aftertreatment system is described for reducing NOX emissions and achieving desired fuel economy. More specifically, a system and method for controlling the exhaust aftertreatment system is provided. The present system being adapted to monitor and control select components of the exhaust aftertreatment system. Specifically, the control system may be adapted to control select components of an exhaust aftertreatment system to adaptively regulate filtration based on various operating conditions of the locomotive.

Abstract: A controller and method of a reducing agent injector capable of accurately providing a required amount of ammonia to a reduction catalyst. A controller for controlling energization of an electromagnetic solenoid, including: a target injection amount calculator for calculating a target injection amount of the reducing agent; a first current output signal calculator for calculating the duration of providing a first current output signal to be provided to the electromagnetic solenoid at the start of injection and calculating the DUTY ratio of the first current output signal; a second current output signal calculator for calculating the DUTY ratio of providing a second current output signal after the first current is provided; a temperature calculator for estimating a temperature within the reducing agent injector; and an output signal corrector for correcting at least one of the first current output signal and the second current output signal based on the temperature estimated.

Abstract: A heater tube for an exhaust system is disclosed. The heater tube may have an open end to receive heated exhaust from a pre-heater. The heater tube may have a closed end located opposite the open end. The heater tube may also have an outer surface extending from the open end to the closed end. The heater tube may further have a fin attached to the outer surface. In addition, the heater tube may have an opening disposed on the outer surface to discharge the heated exhaust.

Abstract: Systems and methods are provided for controlling the amount and timing of nitrogen oxides reductant injected during a given injection cycle into an exhaust system of a vehicle as part of a selective catalytic reduction system. The amount of reductant injected is determined by at least one computational model that accounts for the growth of liquid and/or solid reductant film growth on the interior of the exhaust system. The model determines reductant injection characteristics (e.g., amount, timing, etc.) that reduce and/or eliminate reductant films on the interior of the exhaust system. Exemplary inputs into the model include exhaust temperature, exhaust flow, and the amount of reductant injected in a previous injection cycle.

Abstract: A catalytic converter and muffler including a housing having an inlet disposed between a first end and a second end of the housing to introduce exhaust gases into an inlet chamber. A plurality of first exhaust treatment banks disposed between the inlet and the first end of the housing to allow the exhaust gases flow towards the first end from the inlet chamber into an end chamber. A mixing tube to direct the exhaust gases towards the second end from the end chamber into a flow distributor and a plurality of second exhaust aftertreatment banks and flow into an outlet chamber. At least one resonator chamber defined within the housing to attenuate noise in the exhaust gases.

Abstract: A vehicular fluid injection system including a storage tank, an injection line, a heating system including an electrical heating element being powered by a power source, and a voltage converter inserted between the power source and the heating element, alone or combined with a PWM power regulation.

Abstract: A system and method of effective regeneration of a diesel particulate filter used in the exhaust system of a diesel engine during low engine operating temperatures, is disclosed. Generally speaking, a catalytic burner system and method used in filter regeneration on a diesel engine comprises a burner diesel oxidation catalyst (BDOC) coupled to an exhaust flow of the diesel engine, a mixer fluidly coupled to the BDOC, a diesel oxidation catalyst (DOC) fluidly coupled to the mixer, and a diesel particulate filter (DPF) fluidly coupled to the DOC, wherein the BDOC directs the exhaust flow through the mixer, the DOC and the DPF during a regeneration cycle of the DPF under low engine temperature operating conditions.

Abstract: A metering system for injecting a reducing agent into the exhaust gas flow of an internal combustion engine for selective catalytic reduction, including a reducing agent tank, a metering pump, an air compressor for a compressed air supply, at least one nozzle which is in a flow connection to a pressure line of the compressed air supply and a pressure line of the metering pump and by which the reducing agent can be injected into the exhaust gas flow by means of compressed air, the air compressor being located on a mounting plate and having channels which form intake and pressure lines of the air compressor and which have connection regions at the outlets from the mounting plate and one or more pockets which are in a flow connection to the channels and which form the intake connection and/or the pressure connection of the air compressor.

Abstract: A control system for a vehicle includes a location identification module, an adjustment triggering module, and an adjustment module. The location identification module identifies a location where an engine of the vehicle is expected to be shut down and later re-started with at least one temperature within a predetermined range of an ambient temperature at the time of the re-start. The adjustment triggering module generates a triggering signal when a vehicle location provided by a global positioning system (GPS) is less than a predetermined distance from the identified location. The adjustment module selectively one of increases and decreases a rate at which a dosing agent is injected into an exhaust system, upstream of a selective catalytic reduction (SCR) catalyst, when the triggering signal is generated.

Abstract: Provided is an SCRF article having different SCR catalysts compositions disposed on a wall-flow filter substrate in zones that are arranged in series with respect to the inlet and outlet faces of the substrate. Also provided is method of reducing backpressure and ammonia slip that involves the use of such SCRF articles.

Abstract: A diesel engine including at least one combustion chamber having an exhaust flow therefrom. An injection pump having a plurality of fuel outlets has a corresponding fuel outlet for each of the plurality of fuel outlets that are in controlled fluid communication with the at least one combustion chamber. At least one aftertreatment device is configured for the exhaust flow to travel therethrough. A fuel injector is positioned to inject fuel into the exhaust flow prior to the exhaust flow reaching the aftertreatment device. A valve receives fuel from at least one of the plurality of fuel outlets and the valve is configured to divert a portion of the fuel received by the valve to the fuel injector.

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 apparatus for controlling hydrocarbon delivery in an exhaust gas processing system of an engine that includes a heat generating device and a DPF, comprising a fuel injector and a control manifold, which has a pressure chamber holding compressed air for separating hydrocarbon from exhaust gas, and is fluidly connected to the fuel injector, a fuel control solenoid valve for controlling hydrocarbon supply, a pressure sensor, and a volume changing device, which provides a linear relationship between its volume change and pressure change in the control manifold. With the volume changing device, a deterioration factor value indicative of performance change of the hydrocarbon delivery device can be calculated for compensating temperature control, calculating the hydrocarbon conversion efficiencies of the heat generating device and the DPF in the exhaust gas processing system, detecting failures and mal-functions in the exhaust gas processing system and the engine.

Abstract: A system and method of treating an exhaust flow including nitrogen oxides (NOx) in a turbine engine power generation plant is provided. The turbine engine has a selective catalytic reduction system having a catalyst. During steady state operation of the engine, a reducing agent, such as ammonia, is supplied to an injector in an amount based on a measured molar flow of NOx in the exhaust flow. During a disturbance in the operation of the turbine engine, a reducing agent is supplied to the injector in an amount based on a predicted molar flow of NOx in the exhaust flow. In addition, the system can include a biasing feature in which additional reducing agent is supplied to the exhaust flow beyond the predicted molar flow of NOx. The system and method can mitigate NOx during transient engine operation, an operational mode in which emissions are difficult to predict and control.

Abstract: A method for operating an internal combustion engine is proposed, in whose exhaust gas zone a particle filter is disposed, which is cyclically loaded with particles and thermally regenerated, as well as an apparatus for the implementation of the method, which prevents thermal overload of the particle filter after turning off the internal combustion engine. A test is made when the internal combustion engine is turned off to determine whether an exothermal reaction takes place. Provided that an exothermal reaction takes place in the particle filter, a butterfly valve is closed, which prevents exhaust gas flow through the particle filter and, if the circumstances arise, a resulting oxygenation ingress in the particle filter.

Abstract: An exhaust aftertreatment system for diesel engines includes a filtration station, a NOx reduction station, a temperature sensor, a pressure data generator, a NOx sensor, a reductant dispenser, and a controller. The filtration station filters particulate material from the exhaust. The NOx reduction station reduces NOx concentration in the exhaust. The temperature sensor generates first data that is representative of a temperature of the exhaust. The pressure data generator generates second data that is indicative of a pressure differential across a control volume that is located at the NOx reduction station. The control volume includes at least one catalyzed substrate. The NOx sensor generates third data that is representative of the NOx concentration in the exhaust. The reductant dispenser dispenses reductant into the exhaust. The controller controls a dosing rate of the reductant dispenser. The controller uses the first, second, and third data to determine the dosing rate.

Abstract: Detecting particulate matter in an exhaust filter includes receiving data indicative of a time delay between transmission and reception of electromagnetic energy propagated through trapped particulate matter, and outputting a signal indicative of an amount of the trapped particulate matter responsive to the data.

Abstract: An object of the present invention is to increase the flexibility in the layout of an exhaust gas purification system for an internal combustion engine including selective catalytic reduction catalyst provided in an exhaust passage of the internal combustion engine and an addition device for supplying reducing agent derived from ammonia to the selective catalytic reduction catalyst, without a deterioration of the performance in reducing nitrogen oxides. To achieve the object, the exhaust gas purification system for an internal combustion engine according to the present invention is configured to supply hydrocarbon at the same time when reducing agent derived from ammonia is supplied to the selective catalytic reduction catalyst, thereby producing reducing agent that is hard to be oxidized by a precious metal catalyst.

Abstract: Systems and methods for estimating an efficiency of a catalyst placed in an exhaust path of a combustion engine are disclosed. In one example approach, a method comprises: ageing the catalyst consecutively at different temperatures for definite time periods; measuring the catalyst conversion efficiency after each ageing step; calculating the ageing factor for each step of the ageing procedure and the accumulative value of the ageing factors for all steps of the ageing procedure; estimating catalyst efficiency correlation factors related to the measured catalyst conversion efficiency for each temperature point and for all ageing conditions; determining a correlation between the catalyst efficiency correlation factors and the accumulative value of the ageing factors; and calculating the conversion efficiency of the aged catalyst based on a predetermined correlation between the accumulative ageing factor and the catalyst efficiency correlation factor.

Abstract: A catalyst supported on a substrate includes a heater embedded in a sub-region of the substrate to heat a local region of the catalyst. The amount of ammonia stored on the catalyst may be determined and controlled through conductivity measurements in the locally heated portion of the system described.

Abstract: An LNT (Lean NOx Trap) control method for vehicles increases a purification rate of NOx while preventing an increase in the amount of slip of separated NOx at a relatively low LNT temperature. The method includes a recycle necessity determining step that determines whether to recycle NOx of a LNT in accordance with an amount of adsorbed NOx, a LNT temperature determining step that determines whether a temperature of the LNT is below a predetermined reference temperature, a rich performing step that performs a rich mode when the temperature of the LNT is equal to the reference temperature or above and a pre-rich step that ejects fuel in a rich state when the temperature of the LNT is below the reference temperature.

Abstract: Embodiments of a heating system maintains the temperature of a fuel additive (e.g., AUS32) at and/or above freezing temperature to avoid crystallization. The heating system can form a fluid circuit with one or more coaxially arranged sleeves disposed about hoses that transport the additives. The fluid circuit can also include a central compartment that encloses a flow meter. A fluid heater couples with the fluid circuit to provide heating fluid, e.g., to the central compartment. The heating fluid disperses throughout the heating compartment and into the sleeves, thereby direction heating fluid in thermal proximity to the hoses and other components that handle the fuel additive.

Abstract: A method for predicting a NOx amount may include detecting an O2 amount in an intake air, calculating a reference O2 amount in the intake air according to a driving condition of an engine, calculating a reference NOx amount contained in an exhaust gas according to the driving condition of the engine, and primarily correcting the reference NOx amount based on the detected O2 amount in the intake air and the reference O2 amount in the intake air according to the driving condition of the engine.

Abstract: A cogeneration system includes a fuel evaporator; an internal combustion engine which outputs mechanical energy by combusting fuel evaporated by the fuel evaporator; an electric energy generator that converts the mechanical energy to an electric energy; a cold energy recovery portion which recovers cold energy generated when the fuel evaporator evaporates the fuel; an exhaust heat recovery portion which recovers heat exhausted from the engine; and a gas cleaner that cleans nitrogen oxides contained in gas exhausted from the engine. When the fuel is supplied to the gas cleaner, the fuel reduces the nitrogen oxides by reacting with the nitrogen oxides.

Abstract: Provided are exhaust systems, components, and catalytic articles that have been passivated for use in conjunction with diesel engines that includes a NOx abatement system that uses a reductant. These items are passivated in order to minimize degradation of a reductant in their presence when, for example, they have been subjected to temperatures in excess of 650° C.

Abstract: A reductant injector is configured to dispense a reductant into an exhaust gas feedstream of an internal combustion engine upstream of a selective catalytic reduction device. The reductant injector of a reductant injection system is monitored by generating injector pulsewidth commands corresponding to a prescribed reductant flowrate, monitoring the injector pulsewidth commands, verifying the prescribed reductant flowrate corresponds to the injector pulsewidth commands, monitoring a fluidic pressure in the reductant injection system, estimating a first injected quantity of the reductant corresponding to the injector pulsewidth commands, estimating a second injected quantity of the reductant corresponding to the fluidic pressure in the reductant injection system, and comparing the first and second injected quantities of reductant.

Abstract: An exhaust treatment system for a vehicle includes an intake conduit adapted to receive pressurized intake air provided from a turbocharger compressor and supply the pressurized intake air to an internal combustion engine. An uninterrupted bypass conduit bypasses the internal combustion engine and includes upstream and downstream ends. The upstream end branches from the intake conduit. An exhaust conduit includes an upstream end adapted to receive exhaust from the internal combustion engine. An upstream end of a mixing tube is fixed to and in fluid communication with a downstream end of the exhaust conduit and the downstream end of the bypass conduit at a tubular joint, wherein the exhaust and the pressurized intake air are mixed within the mixing tube. An exhaust treatment device is in fluid communication with a downstream end of the mixing tube.

Abstract: A method for predicting a NOx amount, may include determining a reference NOx amount according to a driving condition of an engine, primarily correcting the reference NOx amount according to an exhaust gas recirculation (EGR) ratio, and secondarily correcting the primarily corrected NOx amount according to an environmental factor and the driving condition.

Abstract: This disclosure relates to a method for controlling a system for regenerating a diesel particulate filter. The method includes monitoring an engine run time that has lapsed since a previous regeneration event. The method also includes monitoring backpressure behind the diesel particulate filter. The method further includes triggering a regeneration flag if the engine run time that lapsed since the previous regeneration event reaches a predetermined time limit and the backpressure exceeds a minimum value.

Abstract: A system for regenerating a particulate filter mounted on an exhaust pipe of a gasoline engine including a plurality of cylinders and an ignition device for igniting fuel and air in the cylinder, a three-way catalyst device mounted on the exhaust pipe connected to the gasoline engine, and to oxidize or reduce exhaust gas, the particulate filter mounted on the exhaust pipe downstream of the three-way catalyst device to trap particulate matter and regenerate the particulate matter using heat of the exhaust gas, a differential pressure sensor mounted upstream and downstream of the particulate filter and to measure a pressure difference of the particulate filter, and a control portion to receive the measured pressure difference and control parameters to determine an amount of non-ignited fuel which is not ignited and flows to the three-way catalyst device among the fuel flowing into the plurality of cylinders.

Abstract: A power system comprising an engine that produces exhaust, a fuel system that injects a fuel into the engine, an aftertreatment system that treats the exhaust, and is controller. The aftertreatment system includes an oxidation catalyst that converts NO from the engine into NO2, a particulate filter that traps soot from the engine, and a sensor that provides an indication of the amount of soot in the particulate filter. The controller increases an engine fuel injection pressure when the amount of soot in the particulate filter is above a threshold.

Abstract: An exhaust treatment device includes first and second substrates positioned in parallel within a housing. A baffle plate supports the substrates, an inlet tube and an outlet pipe, and defines a portion of a first chamber. First ends of the substrates and a second end of the inlet tube is in fluid communication with the first chamber. A partition supports the substrates, the inlet tube and the outlet pipe and defines a portion of a second chamber separate from first chamber. Second ends of the substrates and a second open end of the outlet pipe is in fluid communication with the second chamber. All of the exhaust flows in a first direction through the inlet tube, reverses direction through the substrates and reverses direction again to flow through the outlet pipe.

Abstract: A method to operate a vehicle equipped an internal combustion engine and a transmission coupled to drive wheels. The vehicle is equipped with a parking brake and has an electronic control unit with memory and the engine in fluid communication with an exhaust aftertreatment system. The method includes the steps of determining whether the engine is operating in idle mode for a predetermined period of time; determining whether NOx emissions exceed a predetermined level after the predetermined period of time; and limiting the engine speed not to exceed a predetermined engine speed until an operator engages the parking brake and engages an engine ignition switch.

Abstract: An exhaust system for use with a combustion engine is disclosed. The exhaust system may have an exhaust passage, a reduction catalyst disposed within the exhaust passage, and an injection device configured to inject reductant into the exhaust passage. The exhaust system may also have a sensor configured to generate a signal indicative of a concentration of an exhaust constituent and the reductant, and a controller in communication with the sensor and the injection device. The controller may be configured to make a comparison of a value indicative of a rate of change of the signal for a period of time with a threshold amount, and make a determination of whether the sensor is sensing a concentration of the exhaust constituent or the reductant based on the comparison. The controller may also be configured to adjust operation of the injection device based on the determination.

Abstract: A method of operating an internal combustion engine having a reductant delivery and storage system in an emission control system, comprising of correlating a change in a monitored operating condition with a refill event to determine whether a reductant-diluting substance has been added to the reductant storage system; and limiting vehicle operation based on the correlation.

Abstract: The present disclosure relates to a diesel exhaust treatment device including a catalytic converter positioned upstream from a diesel particulate filter. An electric heater is positioned between the catalytic converter and the diesel particulate filter. A shore station can be used to provide power and combustion air to the diesel exhaust treatment device during regeneration of the diesel particulate filter.

Abstract: A control method for monitoring a soot sensor of an exhaust treatment system is provided. The control method includes: determining when regeneration has completed; comparing soot sensor data to an estimated soot data based on the determining; and generating a message based on the comparing.

Abstract: A method for monitoring a regulated emissions concentration C, in the exhaust gas of an internal combustion engine is provided. The method comprises directing the exhaust gas through an exhaust-gas turbocharger, directing at least a portion of the exhaust gas through an exhaust-gas recirculation system, measuring an air ratio ?meas in the exhaust gas with a lambda probe, measuring a rotational speed nT of the exhaust-gas turbocharger with a sensor, and determining the regulated emission concentration Ci based on the air ratio ?meas and the rotational speed nT. In this way, the emission concentration of the exhaust may be determined as a function of the rotational speed of the turbine.

Abstract: The present invention relates to a method for operating an electromagnetically controllable metering valve, which is disposed in an exhaust gas system of an internal combustion engine. For a metering of reducing agent in the exhaust gas system, the metering valve is actuated by a control and/or regulating device via an electromechanical drive unit with a first current profile, which includes a holding current phase having a first holding current level when said metering valve is open. Said metering valve and the drive unit are part of a metering module. When the internal combustion engine is switched off, said metering valve is actuated via said drive unit with a second current profile, which has a second holding current level that is increased with respect to the first holding current level. An independent claim relates to a control device set up to carry out the method.

Abstract: A method for operating an internal combustion engine of a motor vehicle is provided, wherein at least one SCR catalytic converter for the after-treatment of exhaust gases of the internal combustion engine is present. The method serves to assure that a sufficient quantity of reducing agent is supplied for the operation of the SCR catalytic converter. The motor vehicle has a fuel tank (10) with a fill level sensor A (11) and a reducing agent tank (12) with a fill level sensor B (13). Signals from the fill level sensor B (13) or signals from the fill level sensor A (11) and the fill level sensor B (13) are acquired and evaluated by a navigation unit (16).

Abstract: A system for purifying an exhaust gas may include a lean NOx trap (LNT) catalyst adapted to absorb nitrogen oxides contained in the exhaust gas at a lean atmosphere, release the absorbed nitrogen oxides at a rich atmosphere, and reduce or slip the released nitrogen oxides according to a temperature thereof; a particulate filter adapted to trap particulate matters contained in the exhaust gas and regenerate the trapped particulate matters by using the nitrogen oxides slipped from the LNT catalyst; and a controller adapted to selectively create the rich atmosphere when the temperature of the LNT catalyst is higher than or equal to a first predetermined temperature or a temperature of the particulate filter is higher than or equal to a second predetermined temperature. A method for controlling the system is also disclosed.

Abstract: An exhaust gas treatment device for a diesel engine capable of starting the generation of a combustible gas is provided. The device includes a combustible gas generator. A core member is fitted in the center portion of an annular wall to form an air-fuel mixing chamber between the inner peripheral surface of the annular wall and the outer peripheral surface of the core member. An air-fuel mixture gas in the air-fuel mixing chamber is adapted to be supplied from the end of the air-fuel mixing chamber to a combustible gas generating catalyst to a portion near the center thereof. A heater is used as the core member. The heat dissipating outer peripheral surface of the heater is exposed to the air-fuel mixing chamber. Heat is dissipated directly from the heat dissipating outer peripheral surface of the heater to the air-fuel mixing chamber when starting the generation of the combustible gas.

Abstract: A method for adapting a lean NOx trap (LNT) in an exhaust system of a motor vehicle is provided. The method comprises if a difference between an estimated NOx concentration and a measured NOx concentration in exhaust downstream of the LNT is greater than a threshold, calculating an adaptation value, the estimated NOx concentration downstream of the LNT based on a kinetic model, and adapting the kinetic model, adjusting one or more operating parameters of the LNT, and indicating an aging state of the LNT based on the adaptation value. In this way, the model may be updated in real time to produce a robust prediction of LNT function.

Abstract: An exhaust gas treatment system for an internal combustion engine comprises a particulate filter assembly configured to receive exhaust gas from the engine. The particulate filter assembly comprises an electrically heated catalyst, a particulate filter disposed downstream of the electrically heated catalyst, a hydrocarbon injector, in fluid communication with the exhaust gas, upstream of the electrically heated catalyst and configured to inject excess hydrocarbon into the exhaust gas, an air pump in fluid communication with the exhaust gas upstream of the electrically heated catalyst and configured to deliver air to the exhaust gas to increase the volumetric gas flow rate through, and to decrease the heat residence time in, the particulate filter and a controller configured to operate the hydrocarbon injector, the electrically heated catalyst and the air pump based on predetermined exhaust gas flow rates, temperature thresholds and particulate loadings within the particulate filter.

Abstract: The present invention relates to a dosing module (1) for dosing an urea-based reducing agent into a exhaust gas stream of combustion engine and addressed to an after-treatment system, (30) e.g. SCR or SCRT system. The module (1) comprises an housing (20) which develops along a longitudinal axis (X) and an inlet opening (19) for conveying the exhaust gas. Dosage means (55) are provided for dosing the reducing agent. According to the invention, the inlet opening is annular and inclined with respect to the axis (X) of the housing (20) so as to generate an exhaust gas inlet jet (AJ). Moreover the dosage means are designed so as to generate, inside the housing (20), an urea-based reducing agent spray (UWS) coaxial to the axis (X) of the housing (20).

Abstract: Various diffusion apparatuses are provided for facilitating the injection of a nitrogen-oxides reductant solution, such as urea, into exhaust gas as part of a selective catalytic reduction system. These diffusion apparatuses direct exhaust gas from an exhaust pipe, through a conduit, and into a diffusion chamber where urea is injected. The flow of exhaust gas through the conduit provides improved transport of injected reductant solution into the exhaust pipe, and adhesion of the reductant solution to the walls of the diffusion chamber is reduced.

Abstract: A method of defining a target regeneration temperature setpoint for exhaust gas upstream of a particulate filter of an exhaust gas treatment system includes as defining the regeneration temperature setpoint to include an idle temperature setpoint when the current vehicle operating mode is classified as an idle mode, and defining the regeneration temperature setpoint to include a driving temperature setpoint when the current vehicle operating mode is classified as a driving mode. The idle temperature setpoint and the driving temperature setpoint are derived individually of and separately from each other, and are based on different criteria.

Abstract: A device for providing a liquid reducing agent includes a reducing agent tank for storing the liquid reducing agent. The reducing agent tank has at least one heater disposed in a movable manner in the reducing agent tank and constructed as an active heater. A method for thawing frozen reducing agent and a motor vehicle having the device are also provided.

Abstract: According to one embodiment, an apparatus for evaluating the condition of a NOx adsorber catalyst (NAC) of an internal combustion engine system includes a rich condition timing module, NAC outlet lambda module, and NAC condition module. The rich condition timing module is configured to accumulate the total time during which exhaust gas exiting the NAC has a lambda value less than 1.0. The NAC outlet lambda module is configured to store NAC outlet lambda values of the exhaust gas while the exhaust gas exiting the NAC has a lambda value less than 1.0. The NAC condition module is configured to evaluate the condition of the NAC based on the total time during which exhaust gas exiting the NAC has a lambda value less than 1.0 and an accumulation of the stored NAC outlet lambda values.

Abstract: The invention concerns a procedure for controlling a metering device for metering fuel into the exhaust gas duct of a combustion engine for the regeneration of a particle filter, whereby the metering device supplies the fuel to the exhaust gas duct over a security valve, a first fuel pipe, a metering valve, a second fuel pipe and an injection check valve and whereby the pressure of the fuel is determined between the metering valve and the injection check valve in the second fuel pipe. It is thereby provided that an opening pressure of the injection check valve is determined from the pressure course between the metering valve and the injection check valve.