Abstract: An exhaust purification system that includes a selective catalytic reduction to purify NOx contained in an exhaust gas by using ammonia produced from urea water and an NOx sensor to acquire a value of the NOx contained in the exhaust gas, and the exhaust purification system includes: a reach time measurement unit that measures a reach time of the NOx value acquired by the NOx sensor, the reach time being a required time for the NOx value to reach, from a first predetermined determinative NOx value, a second predetermined determinative NOx value, which is higher than the first determinative NOx value; and a determination unit that determines that malfunction occurs in the NOx sensor when the reach time measured by the reach time measurement unit is equal to or shorter than a first predetermined determinative time.

Abstract: Unique apparatuses, methods, and systems including engine-out emissions controls are disclosed. One embodiment is a system including an internal combustion engine system including at least one fueling actuator and at least one air handling actuator and an electronic controller.

Abstract: A method for operating an exhaust gas purification system connected to an internal combustion engine of a motor vehicle is disclosed. The purification system includes an SCR catalyst for catalyzed reaction of nitrogen oxides contained in the exhaust gas of the internal combustion engine with ammonia. The method includes adding a reducing agent containing ammonia to the exhaust gas upstream of the SCR catalyst at a predeterminable dosage rate and determining a pressure value correlating with an absolute pressure in the exhaust gas purification system on the input side of the SCR catalyst. The dosage rate is specified at least as a function of the pressure value.

Abstract: A multi-gas sensor controller 9 is provided in an urea SCR system 1 with an SCR catalyst 4, an aqueous urea injector 5 and a multi-gas sensor 8 (ammonia sensor unit and NOx sensor unit). The multi-gas sensor controller 9 determines the concentration of ammonia in exhaust gas flowing out of the SCR catalyst 4, as a downstream ammonia concentration value, based on a detection result of the ammonia detection unit. The multi-gas sensor controller 9 controls the aqueous urea injector 5 to supply urea to the SCR catalyst 4 in a fuel-cut state. Further, the multi-gas sensor controller 9 correct the determined downstream ammonia concentration value based on a detection result of the NOx detection unit and an oxygen concentration of the exhaust gas after the supply of urea to the SCR catalyst with the control of the aqueous urea injector 5 by the controller 9.

Abstract: A system includes a hybrid power plant controller programmed to receive a plurality of signals representative of one or more operating parameters of a hybrid power plant. The hybrid power plant includes at least one gas turbine engine, at least one gas engine, and at least one catalyst system. The hybrid power plant controller is programmed to utilize closed-loop optimal control to generate one or more operational setpoints based on the one or more operating parameters for the hybrid power plant to optimize performance of the hybrid power plant. The hybrid power plant controller uses closed-loop optimal control to provide the one or more operational setpoints to respective controllers of the at least one gas turbine engine, the at least one gas engine, and the at least one catalyst system to control operation of the gas turbine engine, the gas engine, and the catalyst system.

Abstract: Systems are provided for a mixer. In one example, the mixer may include tubes and an outer pipe configured to receive exhaust gas.

Abstract: A method for operating a driving system having an internal combustion engine and an exhaust gas purifying device through which exhaust gas from the internal combustion engine flows in order to be purified. The exhaust gas purifying device has at least one catalyst element for catalytic conversion of nitrogen monoxide into nitrogen dioxide at a determined conversion rate. In order to compensate for an age related decrease in the conversion rate of the catalyst element the nitrogen monoxide emission from the internal combustion engine and/or the exhaust gas temperature before the catalyst element are adjusted as a function of the current conversion rate and/or the age of the catalyst element so that the nitrogen dioxide concentration after the catalyst element is greater than or equal to a minimum concentration and/or that the molar ratio between nitrogen monoxide and nitrogen dioxide after the catalyst element corresponds to a predetermined ratio.

Abstract: A control apparatus that includes a measured NOx purification ratio calculation unit calculating a measured NOx purification ratio of a reduction catalyst based on outputs of NOx sensors and provided upstream and downstream of the reduction catalyst reducing nitrogen oxide in an exhaust gas, an estimated NOx purification ratio calculation unit calculating an estimated NOx purification ratio of the reduction catalyst based on a temperature of the reduction catalyst, a flow rate of the exhaust gas, and an absorption amount of the reducing agent by the reduction catalyst, and a reducing agent concentration estimation unit estimating a concentration of the reducing agent injected from a reducing agent injection valve based on the measured NOx purification ratio and the estimated NOx purification ratio.

Abstract: Implementations described herein relate to utilizing discrete transient local state space models to modify an output from a steady state NOx estimation model to provide a final estimated NOx value. An engine operating space, defined by a speed and injection quantity map, is subdivided into several discrete local state spaces and a transient model is developed for each discrete state space to output a NOx estimation correction value. The transient models may be a regression model or the transient model may be an empirical map of data values. The NOx estimation correction value modifies a steady state NOx value to calculate the final NOx estimated value. The final NOx estimated value is then output to another component, such as a controller as an input for controlling one or more components of an engine, an aftertreatment system, and/or a diagnostic system.

Abstract: A snorkel assembly for reading optimization of a sensor, wherein the snorkel assembly may be configured to be positioned around and spaced apart from the sensor. The snorkel assembly may include an upstream side and a downstream side. The snorkel assembly may include a cup section and a tube section extending from the cup section. The tube section may include an inlet opening on the upstream side of the snorkel assembly. The cup section may include an exhaust opening on the downstream side of the snorkel assembly.

Abstract: Disclosed are a method of correcting a control logic of a selective catalytic reduction (SCR) catalyst and an exhaust system. The control logic may be adapted to calculate an injection amount of a reducing agent for the SCR catalyst at the least. The method may include detecting input variables including temperature of the SCR catalyst and exhaust flow rate, discretizing the input variables, standardizing the discretized input variables, determining whether the discretized input variables are within a correction range, and correcting the control logic of the SCR catalyst if the discretized input variables are within the correction range.

Abstract: A method and system for determining changes in the catalytic activity of reforming catalyst where an outlet temperature of the catalytic reactor is measured and a temperature approach to equilibrium calculated based on the measured outlet temperature. The temperature approach to equilibrium is compared to an empirical model-based temperature approach to equilibrium calculated for the same operating conditions, the comparison showing changes in the catalytic activity of the reforming catalyst.

Abstract: A selective catalytic reduction (SCR) catalyst is disposed in an exhaust gas system of an internal combustion engine. A reductant injector is coupled to the exhaust gas stream at a position upstream of the SCR catalyst, and first and second NOx sensors provide NOx measurements upstream of and downstream of the SCR catalyst, respectively. A system and method is disclosed for operating the system to determine a NOx amount and/or a NH3 slip amount downstream of the SCR catalyst by decoupling NOx-NH3 measurements from the output of the second NOx sensor to provide control of the reductant injection amount.

Abstract: When a catalyst temperature of a catalyst device is at or below a lower limit air-fuel ratio richness control is prohibited. When a first timing, where an estimated value of a NOx storage amount has reached an enrichment start threshold value, and a second timing, based on a set interval time in an enrichment interval time map, are both satisfied, the control is started. The second timing is corrected by multiplying the set interval time by an enrichment interval correction coefficient preset based on the catalyst temperature and a storage ratio of the estimated value of the NOx storage amount to an enrichment start threshold value of the NOx storage amount. The frequency of the air-fuel ratio richness control of a catalyst device configured to recover a purification capacity of a catalyst is reduced, and the catalyst temperature is raised while preventing white smoke development and hydrocarbon slip, to thereby achieve improvement in exhaust gas composition and improvement in fuel efficiency.

Abstract: A thermal management system for an aftertreatment system includes an air pump and a compressed air rail. The compressed air rail is fluidly connected with the air pump. The thermal management system further includes a first valve located between the compressed air rail and an exhaust outlet pathway. The first valve is configured to selective supply air to the aftertreatment system of the engine. The thermal management system further includes a heater located between the compressed air rail and the first valve. The heater is configured to heat the air before supplying air to the aftertreatment system of the engine.

Abstract: A method is disclosed for regulating an exhaust after-treatment (AT) system for a diesel engine. The method includes detecting the engine's cold start when the engine's exhaust gas flow directed into the AT system is at a temperature below a threshold value. The method also includes determining flow-rates of the engine's exhaust gas and its fuel supply. The method additionally includes determining a magnitude of exhaust gas energy using the determined exhaust gas flow-rates and the fuel supply over an elapsed time following the cold start. The method also includes integrating a detected temperature of the exhaust gas over the elapsed time and comparing the determined magnitude of exhaust gas energy with the integrated temperature. Furthermore, the method includes regulating operation of the AT system using the determined exhaust gas temperature when the determined magnitude of exhaust gas energy is within a predetermined value of the integrated exhaust gas temperature.

Abstract: A method of calculating an ammonia (NH3) mass generated in a lean NOx trap (LNT) of an exhaust purification device includes sequentially calculating a NH3 mass flow at a downstream of each slice from a first slice to an n-th slice, and integrating the NH3 mass flow at the downstream of the n-th slice over a predetermined time, wherein the calculation of the NH3 mass flow at the downstream of the i-th slice comprises calculating a NH3 mass flow flowing into the i-th slice, calculating a NH3 mass flow generated at the i-th slice, and adding the NH3 mass flow generated at the i-th slice to a value obtained by subtracting the NH3 mass flow used to reduce the NOx and the O2 at the i-th slice from the NH3 mass flow flowing into the i-th slice.

Abstract: In a heather control apparatus for a gas sensor, a CPU obtains upper and lower limit values by adding a predetermined value to and subtracting the predetermined value from an Rpvs average obtained in a last heater energization period (or to an Rpvs value obtained for the first time), and sets a window W1. The CPU obtains a plurality of Rpvs values [P2] to [P11], and obtains an Rpvs average A1 while excluding Rpvs values [P5], [P6], and [P9] which do not fall within the window W1 (not less than the lower limit value and not greater than the upper limit value). The CPU obtains the upper and lower limit values by adding the predetermined value to and subtracting the predetermined value from the Rpvs average A1, and sets a window W2 for the next heater energization period.

Abstract: Methods are disclosed for determining an oxidation state of a catalyst using RF signals. The method may include introducing radio-frequency signals into a resonant chamber including a catalyst, modulating an air-fuel ratio of an engine upstream of the catalyst to generate a sequence of uniform pulses and at least one altered pulse that differs from the uniform pulses, and comparing a frequency response of two or more resonant modes of the radio-frequency signals during the sequence to determine an oxidation state of the catalyst. The method may further include adjusting the air-fuel ratio based on the comparing step. Two or more altered pulses may be inserted into the air-fuel ratio sequence. The altered pulse may have a pulse width and/or amplitude that differs from the uniform pulses. The methods may be used to adjust an air-fuel ratio to correct or impart a bias.

Abstract: This control device for an internal combustion engine is equipped with: an air/fuel ratio sensor provided to the exhaust passage of an internal combustion engine; and an engine control device that controls the internal combustion engine according to the output of the air/fuel ratio sensor. The air/fuel ratio sensor is equipped with: a gas chamber to be measured, into which exhaust gas flows; a pump cell that pumps oxygen into or out of the gas chamber to be measured according to the pump current; and a reference cell of which the reference cell output current detected varies according to the air/fuel ratio inside the gas chamber to be measured. The reference cell is equipped with: a first electrode that is exposed to the exhaust gas in the gas chamber to be measured; a second electrode exposed to a reference atmosphere; and a solid electrolyte layer arranged between the electrodes.

Abstract: The invention has an object to control an EGR amount accurately in transient time. An ECU switches EGR control to the one-valve EGR control and the both-valve EGR control based on a request EGR amount. When the EGR control is switched to the one-valve EGR control from the both-valve EGR control, an EGR valve of one bank is closed first. Next, during a time period until an opening degree restriction time period elapses after the EGR valve is closed, an opening degree of an EGR valve of the other bank is restricted to be smaller than a one-valve target opening degree. Subsequently, when the opening degree restriction time period elapses, restriction of the opening degree of the EGR valve is cancelled, and the opening degree of the EGR valve is changes to the one-valve target opening degree.

Abstract: An internal combustion engine comprises an exhaust purification catalyst arranged in an exhaust passage of the internal combustion engine and being able to store oxygen in inflowing exhaust gas and an air-fuel ratio sensor arranged at a downstream side of the exhaust purification catalyst in a direction of exhaust flow and detecting an air-fuel ratio of exhaust gas flowing out from the exhaust purification catalyst and stops or decreases a feed of fuel to a combustion chamber as fuel cut control. The abnormality diagnosis system calculates a characteristic of change of an air-fuel ratio based on an output air-fuel ratio output from the air-fuel ratio sensor at the time when the output air-fuel ratio first passes a part of an air-fuel ratio region of a stoichiometric air-fuel ratio or more after an end of the fuel cut control, and diagnoses abnormality of the air-fuel ratio sensor based on the characteristic of change of the air-fuel ratio.

Abstract: A secondary-air supply structure for a saddle-ride type vehicle includes a cylinder block and a cylinder head which extend upward from a crankcase, and right and left secondary-air supply pipes which are connected to the right and left of an exhaust outlet portion of the cylinder head and through which secondary air is supplied to an exhaust port. The right and left secondary-air supply pipes extend from the front surface of the cylinder head to the right and left of the cylinder head, respectively, and include bent-back pipe sections extending along the right and left surfaces of the cylinder head and bent back toward the front side.

Abstract: A diagnostic device includes: a DOC for oxidizing hydrocarbon (HC) contained in an exhaust gas; a first sensor for detecting an exhaust gas temperature at a DOC inlet; a second sensor for detecting an exhaust gas temperature at a DOC outlet; a third sensor for detecting ambient temperature; an HC heat generation rate calculation unit which calculates, based on detection values of the first and second sensors, a difference in an exhaust gas heat quantity between upstream and downstream sides of the DOC, calculates, based on the detection values of the three sensors, a heat loss quantity released to outside air from the DOC, and adds the heat loss quantity and the exhaust gas heat quantity difference to calculate a heat generation quantity of HC in the DOC; and a DOC deterioration determination unit which determines, based on the calculated HC heat generation quantity, deterioration of the DOC.

Abstract: The disclosure relates to a system and method for identifying whether a difference between measured lambda and computed lambda, based on mass air flow and mass fuel flow, is due to a drift in fuel metering or a drift in air metering. The determination is based on also measuring exhaust gas NOx using a NOx sensor. By comparing the measured NOx to modeled NOx, drift can be attributed appropriately to the air flow measurement and/or the fuel flow measurement. Appropriate correction in the calibration can be undertaken to overcome sensor drift and/or drift in the fuel injector/fuel system flow characteristics.

Abstract: An abnormality diagnosis apparatus includes an exhaust gas purification apparatus arranged in an exhaust passage of an internal combustion engine and including a SCR catalyst; a supply apparatus supplying an additive such as ammonia to the exhaust gas purification apparatus; an EGR apparatus recirculating a part of exhaust gas from the exhaust passage at a downstream side of a position of supplying the additive to an intake passage; obtaining means for obtaining a NOx inflow amount into the exhaust gas purification apparatus; diagnosing means for calculating a physical quantity correlated to a NOx purification performance of the exhaust gas purification apparatus using the obtained NOx inflow amount, and diagnosing that an abnormality has occurred in the exhaust gas purification apparatus when the physical quantity is smaller than a threshold; and correcting means for, when the additive is recirculated together with a part of the exhaust gas, correcting the threshold to a smaller value than when otherwise.

Abstract: A water jet propulsion watercraft includes an exhaust passage, a catalyst member, a water lock, a first oxygen sensor, and a second oxygen sensor. The exhaust passage guides exhaust gas from an engine to an exterior of a hull of the watercraft. The catalyst member is arranged inside the exhaust passage. The water lock is arranged in the exhaust passage downstream of the catalyst member. The first oxygen sensor is arranged in the exhaust passage upstream of the catalyst member. The second oxygen sensor is arranged in the exhaust passage at a position downstream of the catalyst member and upstream of the water lock.

Abstract: Systems and methods are provided for controlling a selective catalyst reduction (SCR) system having a SCR reactor. A reductant slip set point indicative of a target slip is received as a control variable is to be utilized for maintaining an amount of a NOx composition included in a combustion gas below a selected limit. A signal transmitted by a sensor is received, and is indicative of the reductant slip downstream of the SCR reactor. An amount of a NOx reductant to be introduced to the SCR reactor is determined based, at least in part, on a relationship between the target reductant slip and the reductant slip downstream of the SCR reactor indicated by the signal. A control signal is transmitted to cause introduction of the amount of the NOx reductant to the SCR reactor to maintain the amount of the NOx composition in the combustion gas below the selected limit.

Abstract: A system includes a filtering module that filters a first signal that indicates an amount of nitrogen oxides (NOx) in exhaust gas upstream from a catalyst, and that filters a second signal that indicates amounts of NOx and ammonia (NH3) in exhaust gas downstream from the catalyst. A slip determination module determines whether NH3 is present in exhaust gas downstream from the catalyst based on a frequency response of the first and second signals.

Abstract: A control device of an internal combustion engine which is provided with an exhaust purification catalyst is provided with a downstream side air-fuel ratio sensor, a feed control means for controlling the fuel feed amount so that the air-fuel ratio of the exhaust gas becomes a target air-fuel ratio, and an excess/deficiency estimating means which estimates an oxygen excess/deficiency in the exhaust gas. The target air-fuel ratio is switched to a lean air-fuel ratio when the output air-fuel ratio of the downstream side air-fuel ratio sensor becomes a rich air-fuel ratio and is switched to the rich air-fuel ratio when the stored amount of oxygen of the exhaust purification catalyst after this becomes a switching reference amount or more.

Abstract: A method of controlling a concentration of hydrocarbons in exhaust gas from an internal combustion engine includes sensing an oxygen percentage of the flow of exhaust gas from the internal combustion engine and determining a concentration of hydrocarbons in the flow of exhaust gas. An engine control module may then adjust the sensed oxygen percentage of the exhaust gas based on the determined concentration of hydrocarbons in the flow of exhaust gas to define a corrected oxygen percentage. The control module may then control at least one of a hydrocarbon injection rate for in-cylinder combustion of the internal combustion engine, and a hydrocarbon injection rate for a post combustion exhaust gas treatment process, based on the corrected oxygen percentage, to control the concentration of hydrocarbons in the exhaust gas.

Abstract: A system includes a controller that has a processor configured to receive a first signal from a first oxygen sensor indicative of a first oxygen measurement, wherein the first oxygen sensor is disposed upstream of a catalytic converter system; and to receive a second signal from a second oxygen sensor indicative of a second oxygen measurement, wherein the second oxygen sensor is disposed downstream of the catalytic converter system; and to execute a catalyst estimator system, wherein the catalyst estimator system is configured to derive an oxygen storage estimate based on the first signal, the second signal, and a catalytic converter model. The processor is configured to derive a system oxygen storage setpoint for the catalytic converter system based on the catalytic converter model and the oxygen storage estimate.

Abstract: A control device for an internal combustion engine, equipped with: an exhaust purification catalyst capable of storing oxygen; a downstream-side air-fuel ratio sensor arranged downstream in the direction of flow of exhaust from the exhaust purification catalyst; and an air-fuel ratio control device that controls the air-fuel ratio such that air-fuel ratio of the exhaust flowing into the exhaust purification catalyst reaches a target air-fuel ratio.

Abstract: The systems and methods herein relate the operation of a particle filter which is arranged in an exhaust-gas path of an internal combustion engine, to a device for exhaust-gas aftertreatment which can be operated in accordance with the method that comprises determining a mass flow rate of an exhaust-gas flow flowing in the exhaust-gas path; and supplying ambient air into the exhaust-gas path as a function of the determined mass flow rate. By this method, the spontaneous regeneration of a particle filter within the exhaust system may be abated.

Abstract: Various embodiments relate to a method of operating an engine system with injectors having nozzle sac volume. The engine system may be a four-stroke, high power engine having a high-pressure common-rail injection system. A number of engine cylinders to fire is selected based on a fuel injection quantity per selected engine cylinder such that a nitrogen oxides (NOx) emission is less than a first predetermined threshold and a smoke value is less than a second predetermined threshold. The fuel injection quantity per cylinder may be higher than a nominal fuel injection quantity to improve fuel injector spray characteristics. The exhaust can be mixed with fresh air blowout from deactivated cylinders to further reduce smoke value. The engine system is operated with a firing pattern for the selected number of cylinders to fire.

Abstract: A method is disclosed for controlling a diesel engine equipped with a diesel particulate filter (DPF). The method includes detecting steady state operation of the engine generating a first flow rate of particulate matter (PM) directed into the DPF. The method also includes, during the steady state operation, triggering exhaust gas recirculation to the engine and thereby directing a second PM flow rate that is greater than the first flow rate into the DPF. The method additionally includes detecting a PM flow rate exiting the DPF in response to the second PM flow rate directed into the DPF. The method also includes comparing the detected PM flow rate exiting the DPF with a PM flow rate threshold. Furthermore, the method includes regulating injection of fuel to regenerate the DPF, if the detected PM flow rate exiting the DPF is greater than the PM flow rate threshold.

Abstract: An internal combustion engine with multiple cylinders and injection valves that are provided for the cylinders and that meter fuel also comprises an exhaust gas tract in which an exhaust gas catalytic converter is arranged. A characteristic value (OSC) of an oxygen storage capacity of the exhaust gas catalytic converter is determined. In accordance with the characteristic value (OSC), a heating measure (HM) for heating the exhaust gas catalytic converter is carried out.

Abstract: A system for diagnosing and/or determining the performance of a reductant delivery system may include determining a flow rate offset value for the reductant delivery system. A reduced reductant flow rate may be determined for a reductant dosing command value based, at least in part, on the determined flow rate offset when reductant dosing command is non-zero. A reductant flow rate error can be determined based, at least in part, on a difference between an expected reductant flow rate value corresponding to the reductant dosing command value and the determined reduced reductant flow rate. A performance status value indicative of a performance status of the reductant delivery system may be outputted based, at least in part, on the determined first reductant flow rate error and a predetermined threshold.

Abstract: A power system may include an internal combustion engine, an exhaust gas recirculation system, a selective catalytic reduction system, and an engine control module. The internal combustion engine includes a plurality of combustion cylinders and a plurality of corresponding intake valves for controlling a flow of air from an intake into the cylinders. The engine control module is configured to adjust a closure timing of the intake valves based on at least one engine parameter and optimization of an operational cost of the power system. A method for controlling the power system may include recirculating a portion of an exhaust flow, injecting a reductant into the exhaust flow, and adjusting a closure timing of the intake valves based on at least one engine parameter and optimization of an operational cost of the power system.

Abstract: A method for operating an exhaust-gas aftertreatment system arrangement is provided. The method includes in a first operating state, flowing a substantial majority of an exhaust-gas stream from the internal combustion engine through a first NOx storage catalytic converter positioned in a main exhaust branch of an exhaust aftertreatment system arrangement and in a second operating state, flowing a substantial majority of the exhaust-gas stream through a first bypass branch branching off from the main exhaust branch upstream of the first NOx storage catalytic converter and which opens into the main exhaust branch downstream of the first NOx storage catalytic converter and regenerating the first NOx storage catalytic converter.

Abstract: A method for controlling a motor vehicle with an internal combustion engine and a catalytic converter is disclosed. The method includes: determining an oxygen storage value, which is a dimension for oxygen stored in the catalytic converter, detecting an engine load, carrying out a part evacuation of the oxygen from the catalytic converter with a fuel enrichment when the oxygen storage value exceeds a trigger evacuation threshold value and when the engine load is below a low-load threshold value.

Abstract: A pump share-type urea water supply system includes a first supply valve and a second supply valve. A urea water tank is connected with the respective supply valves by a urea water supply path that includes a first supply path for the first supply valve and a second supply path for the second supply valve. The second supply path has a larger capacity than the first supply path by a predetermined volume. A suck-back control controls opening and closing of the respective supply valves such that a first estimated valve-opening time of the first supply valve for suck-back control in the first supply valve and supply path is shorter than a second estimated valve-opening time of the second supply valve for suck-back control in the second supply valve and in-the-second supply path by at least a first control time corresponding to the predetermined volume.

Abstract: A method for diagnosing a selective catalytic reduction (SCR) catalyst of an exhaust aftertreatment system of an internal combustion engine includes ensuring that a SCR catalyst NH3 storage level is substantially below the current maximal NH3 storage capacity of the SCR catalyst, initiating over-injection of reductant by the injector, stopping reductant injection upon registering, by the exhaust gas sensor, an increasing NOx+NH3 emission level and an NOx+NH3 emission level exceeding a predefined threshold value, and when the reduction injection is stopped recording an output signal of the exhaust gas sensor until an indication of a minimal or negligible SCR catalyst NH3 storage level is determined, and calculating a SCR catalyst NH3 storage capacity on the basis of the recorded output signal.

Abstract: A method for monitoring the function of an exhaust-gas sensor in the exhaust duct of an internal combustion engine. A first function control of the exhaust-gas sensor takes place in a first operating point of the internal combustion engine, and in the case of an intact exhaust-gas sensor, the output signal of the exhaust gas sensor or a characteristic quantity derived therefrom is determined in at least one second operating point of the internal combustion engine in the case of an intact exhaust-gas sensor and stored as learned value, and the monitoring of the function of the exhaust-gas sensor during a subsequent operation of the internal combustion engine in the second operating point takes place by comparing the output signal of the exhaust-gas sensor or the characteristic quantity derived therefrom, with the learned value. A corresponding device for implementing the method is also described.

Abstract: The deterioration judgment for an absorption reduction type NOx catalyst (1) is performed quickly and correctly. A catalyst deterioration judging system comprises a supply unit (5) which supplies a reducing agent, a measuring unit (8) which measures a NOx concentration in an exhaust gas at a position downstream from the catalyst (1), a control unit (10) which regulates an amount of the reducing agent so that an air-fuel ratio of the exhaust gas is a lean air-fuel ratio when the reducing agent is supplied from the supply unit (5), and a judging unit (10) which judges deterioration of the catalyst (1) on the basis of the NOx concentration measured by the measuring unit (8) when the amount of the reducing agent is regulated so that the air-fuel ratio of the exhaust gas is the lean air-fuel ratio when NOx is absorbed by the catalyst (1).

Abstract: A method of estimating a mass flow rate of nitrogen oxides in exhaust gas includes sensing a mass flow rate of a flow of exhaust gas from the engine. A nitrogen oxides base concentration for when the engine is operating at a reference state is defined, and a nitrogen oxides ratio for a current operating state of the internal combustion engine is calculated. The mass flow rate of the flow of exhaust gas, the nitrogen oxides base concentration, and the nitrogen oxides ratio for the current operating state of the engine are multiplied together to define an estimated value of the current mass flow rate of nitrogen oxides in the flow of exhaust gas from the engine. The estimated value of the mass flow rate of nitrogen oxides may be compared to the output from a nitrogen oxides sensor to determine proper functionality of the nitrogen oxides sensor.

Abstract: A method for controlling dosing of a diesel exhaust fluid includes providing a diesel engine and an exhaust system. The exhaust system includes an exhaust aftertreatment device and is coupled to the diesel engine. An injection device is provided in the exhaust system for dosing the diesel exhaust fluid into the exhaust system according to a predetermined routine. A water condensation content of the exhaust aftertreatment device is determined. A dosing event, directed by the predetermined routine, is precluded so that the injection device is not operated to provide diesel exhaust fluid to the exhaust aftertreatment device when the water condensation content of the exhaust aftertreatment device is determined to be above a specified threshold value.

Abstract: An exhaust emission purification control device for an engine that accurately estimates an accumulated oxygen amount of a catalyst at a terminating time of a reduction treatment which includes a secondary air injector that injects secondary air within an exhaust path, a sensor which detects an air-fuel ratio in a downstream side of a catylyst, a count-value accumulator which estimates an accumulated oxygen amount (a count value) in the catalyst during the secondary air injection, and a rich spike controller which performs rich injection after the secondary air injection. The device includes a count-value corrector that multiplies the count value after the secondary air injection by a correction coefficient derived from an output value SVO2 of the O2 sensor during termination of reduction treatment, so as to estimate the accumulated oxygen amount during the termination of the reduction treatment.

Abstract: In a method for operating a gas turbine (10), a CO2-containing gas is compressed in a compressor (13), the compressed gas is used to burn a fuel in at least one subsequent combustion chamber (14, 18), and the hot combustion gases are used to drive at least one turbine (17, 21). Improved control and performance can be achieved by measuring the species concentration of the gas mixture flowing through the gas turbine (10) at several points within the gas turbine (10) by a distributed plurality of species concentration sensors (22; 22a-1; 23), and utilizing the measured concentration values to control the gas turbine (10) and/or optimize the combustion performance of the gas turbine (10).

Abstract: An exhaust-gas purification system and method are provided for an internal combustion engine having an NOx storage catalytic converter and a downstream SCR catalytic converter. The NOx storage catalytic converter can be supplied in a first operating mode with an oxidizing exhaust gas and in a second operating mode with a reducing exhaust gas. A third operating mode is provided between the first operating mode and the second operating mode, in which an exhaust gas which has a lower content of oxidizing constituents than the first operating mode and a lower content of reducing constituents than the second operating mode can be supplied to the NOx storage catalytic converter to improve NH3 production at the start of converter regeneration.