Abstract: An optical window assembly of an optical sensor of a downhole tool positionable in a wellbore penetrating a subterranean formation. The downhole tool has a housing with a flowline there through to receive downhole fluid therein. The optical sensor is positionable about the flowline to measure light passing therethrough. The optical window assembly includes a tubular sensor body positionable in the housing (the sensor body having a sensor-end and a flanged signal-end with a passage there through), an optical window positionable in the passage of the sensor body to pass the light from the flowline to the optical sensors, a seal disposed about the sensor body, and a backup ring disposed about the sensor body between the flanged signal-end and the seal to support the seal about the sensor body whereby the downhole fluid is prevented from leaking between the seal and the sensor body.

Abstract: A downhole tool includes a body including an opening and a cavity extending into the body from the opening. A sample container is fixed in the cavity and includes an elongated container for holding a formation fluid sample and a sheath coupled to an outer surface of the elongated container and at least partially surrounding the elongated container.

Abstract: A profile of a cutting tip includes a convex portion extending from a cutting end to an inflection point located at an axial and radial distance from the cutting end. A concave portion extends from the inflection point to a point at a greater radial and axial distance from the cutting end. The profiles of the generally concave portion and the generally convex portion have a first linear portion defined by a portion of a first line extending from a first point at a first radial position to a second point at a second radial position and axially spaced from the first point. A second linear portion is defined by a portion of a second line extending from a third point to a fourth point at the second radial position and at an axial distance from the second point corresponding to about half a length of the first line.

Abstract: The invention relates to a method for replacing a disk cutter (1) mounted with preload in a casing (2) attached to the cutting head of a tunnel boring machine, operated using a disk cutter (1) bearing, firmly attached thereto, an element (4) for locking into the housing (2) and preloading means (5), the method involving the steps of: a) removing a worn disk cutter (1) from said housing (2): • clamping a disk cutter (1) handling device (3) onto the housing (2); • taking hold of the disk cutter, • releasing the preload, • unlocking, • extracting the disk cutter (1), • unclamping the device (3), b) fitting a replacement disk cutter (1) in reverse order.

Abstract: The present application relates to a system for supporting a roof of a portion of a mine. The system includes a first plurality of stabilizing members disposed above the roof at a first elevation. The first plurality of stabilizing members originate from a first common location and terminate at a second elevation that is higher than the first elevation. The system further includes a second plurality of stabilizing members disposed above the roof and the first plurality of stabilizing members at a third elevation. The second plurality of stabilizing members originate from a second common location and terminate at a fourth elevation that is higher than the third elevation. The second plurality of stabilizing members are disposed generally perpendicular to the first plurality of stabilizing members.

Abstract: Synergistic Energy Ecosystem using a co-generation system and method wherein waste energy from waste heat producers within an enclosure including an electric generator is reclaimed to supply heat to the cold end of a heat pump within the enclosure for optimized use in space heating a habitat and to the management of the distribution of electricity from the generator so as to supply electricity to the habitat and to neighboring habitats when efficient, cost-effective or required to do so by distribution policies managing the energy eco-system.

Abstract: Cylinder unit of a high pressure pump for a fluid. Cylinder unit includes a cylinder formed by at least two concentric tubular components coupled by a shrink connection. A flange part with sealing system is detachably connected on one side of the cylinder, and sealing system has a movable plunger and a bearing bushing. A valve body is connected on other side of the cylinder. Bearing bushing and radially outermost component are arranged to bear against flange part to form an intermediate gap, a spring device has a distal portion supported on outermost component of the cylinder and a proximal portion on an outside of bearing bushing, and a valve body against which an other side of the cylinder bears are included. The tubular components have a metallic connection in a region of a surface bearing between the valve body and the cylinder.

Abstract: A scroll pump includes a frame, a stationary plate scroll, an orbiting plate scroll, a non-energized type of tip seal or seals, an eccentric drive mechanism assembled to and supported by the frame and to which the orbiting plate scroll is assembled so as to be drivable by the eccentric drive mechanism in an orbit about a longitudinal axis of the pump, and an axial compliance system including a flexure. The flexure is interposed between a bearing of the eccentric drive mechanism and a flexure-locating surface of the eccentric drive mechanism. The flexure allows the orbiting plate scroll to move away from the stationary plate scroll in the case of an assembly process which would otherwise result in the tip seal(s) being too forcefully engaged with the plate of the opposing plate scroll.

Abstract: The invention relates to a method for welding rotors for power generation such as gas turbines, steam turbines, and generators having a plurality of rotor discs arranged along a rotor axis. The method includes providing said discs with a weld seam preparation. The weld seam preparation includes a root, a first, gap-like welding section adjoining the root in radial direction, and a second, gap-like welding section adjoining the first welding section in radial direction. The method further includes melting the root by means of a first welding process; making a weld in the first welding section by means of a second welding process; and filling up the second welding section by means of a third welding process.

Abstract: A turbine includes an annular turbine blade body disposed on a flow path, a diaphragm outer ring installed at a tip side of the annular turbine blade body via a clearance, and seal fins formed to protrude from the diaphragm outer ring and configured to form small clearances with the annular turbine blade body, wherein dead water region-filling sections are formed in cavities in which main vortexes are generated, such that a dead water region that the main vortexes cannot reach is filled.

Abstract: In accordance with an exemplary embodiment, a method for manufacturing a component using additive manufacturing techniques includes providing a 3D design model for the component, adding one or more crack resistant features to the 3D design model of the component to produce an enhanced design model, and manufacturing the component using an additive manufacturing technique in accordance with the enhanced design model. The one or more crack resistant features are provided to reduce or eliminate the incidence of cracking in the manufactured component.

Abstract: A propeller blade includes a foam core and a structural layer that surrounds at least a portion of the foam core and includes a face side and a camber side is disclosed. The propeller blade also includes an insert disposed in the foam core in operable contact with the face side and the camber side of the structural layer.

Abstract: A rotor blade including a main portion having a main portion leading edge shield; a main portion impact-resistant layer formed on a nose of the leading edge shield; a main portion erosion-resistant layer formed on a top and bottom of the main portion, rearward of the main portion impact-resistant layer; a main portion foil formed on the top and the bottom of the main portion rearward of the main portion erosion-resistant layer; a tip cap having a tip cap leading edge shield; a tip cap impact-resistant layer formed on a surface of the tip cap leading edge shield; and a tip cap foil formed on the top and the bottom of the tip cap rearward of the tip cap erosion-resistant layer.

Abstract: The present invention relates to a compressor blade of a gas turbine having an airfoil made of a fiber-reinforced plastic, which is fastened by means of a blade root to a disk, as well as a metallic leading-edge element, which is arranged on the leading-edge side of the airfoil and partially encompasses the latter, with the leading-edge element itself being fastened to the disk.

Abstract: An airfoil includes a pressure surface and a suction surface extending from a root section of the airfoil to a tip section of the airfoil. The airfoil also includes a leading edge and a trailing edge defining a chord length of the airfoil therebetween. The airfoil further includes a tip shelf formed along the tip section of the airfoil between the pressure surface and a tip shelf wall. The tip shelf wall is spaced between the pressure surface and the suction surface and the tip shelf extends from within 10% of the chord length measured from the leading edge to within 10% of the chord length measured from the trailing edge.

Abstract: A pinned root fixing arrangement of axial flow steam turbine rotor discs made of a low alloy that is less susceptible to stress corrosion cracking (SCC). Such an arrangement has a first ratio, which is defined as ratio of the axial breadth of the disc fingers and the sum of the axial breath and the axial breadth G of the gap between adjacent disc fingers, in the range of about 0.4 to about 0.6 and further has a second ratio, which is defined as the ratio of the length of the disc fingers and the blade fingers to the diameter, between 4 and 6.

Abstract: An airfoil blade of a gas turbine engine includes a root configured for mating attachment with a cooperating rotor hub and an airfoil extending away from the root. The root is composed of a first metal and has a nanocrystalline metal coating, composed of a second metal, over at least a portion thereof. A method of protecting such a blade by applying a nanocrystalline metal coating to a portion of the blade root is also disclosed.

Abstract: A device for locking a root of a rotor blade in a groove in a rotor disk of a turbomachine including: a circular ring sector configured to be mounted, transversely to the axis of the turbomachine, in a groove in the rotor disk; at least one locking wedge, which is rigidly secured and perpendicular to the ring sector, and extends parallel to the axis of the ring sector so as to hold the root of the blade radially in the groove; and at least one locking tooth extending from the ring sector radially with respect to the axis of the ring sector, so as to prevent the root of the blade from moving axially in the groove.

Abstract: A helical ring including a polygonal body and a plurality of cylindrical radial housings arranged in the body is provided. Each housing includes a surface adapted to receive a support of a blade of a helix. The surface of each housing is arranged on a radially internal surface of a corresponding hub. Each hub is a separate piece attached to the body of the ring, intended to be received in a radial housing of the body of the ring. The hub includes two projecting pins relative to its external surface to be fastened to the edges of a housing of the annular body, the two projecting pins forming a centering axis.

Abstract: A combustor transition adapted to guide combustion gases in a hot gas flow path extending between a can combustor and a first stage of turbine in a gas turbine is disclosed. The combustor transition includes a duct having an upstream end adapted for connection to the can combustor and a downstream end adapted for connection to a first stage of a turbine, wherein the downstream end includes an outer wall, an inner wall, a first and a second side wall. At least one side wall has a side wall extension which extends in a downstream direction beyond the outlet. The side wall extension at least partly encloses a first resonator volume and at least one side wall extension includes a resonator hole, which is configured as a neck of a Helmholtz-damper. A method for retrofitting a gas turbine and method for borescope inspection of a GT are disclosed.

Abstract: A variable-vane assembly has a nozzle ring supporting an array of pivotable vanes, and a unison ring for pivoting the vanes in unison. A crank mechanism rotatably drives the unison ring, and includes an external crank assembly positioned radially outward of the unison ring, a non-round drive block disposed in a non-round recess in an outer periphery of the unison ring, and a crank arm having a forked end connected to the drive block and an opposite end connected to the external crank assembly. The forked end defines two legs and the drive block is disposed between the legs and is pivotally connected to the legs such that the drive block is pivotable relative to the crank arm about a pivot axis. The crank mechanism is arranged such that the crank arm is caused to swing through an arc of movement, thereby rotating the unison ring.

Abstract: A method of fabricating a turbine engine shaft from a metal billet of generally cylindrical shape, the method including drilling the billet to form a through axial cylindrical bore therein, engaging a cylindrical insert in the bore, the insert being made of a material having yield stress close to that of the material of the billet so that the materials of the insert and of the billet have substantially the same behavior during forging, hot forging the billet to form a forged blank of length greater than that of the billet, withdrawing the insert, and machining the blank.

Abstract: The invention refers to a process for the formation of a thermal barrier coating on a substrate, comprising the steps of: a) applying a bond coat on the substrate; b) subjecting the bond coat to a low activity aluminizing process, thus obtaining, above the bond coat, a temporary intermediate diffusion layer; c) applying, on the temporary intermediate diffusion layer, aluminum powder in suspension with a solvent or aqueous base, said aluminum powder having size distribution from 15 to 150 ?m; d) performing a thermal treatment in a vacuum at a pressure from 10?3 to 10?5 bars, at a temperature from 800° C. to 1050° C. and with an active phase having duration in the range of 60 minutes to 4 hours, thus obtaining above the bond coat an enriched intermediate diffusion layer; and e) applying a definitive barrier layer on said enriched intermediate diffusion layer.

Abstract: The present application provides a control valve actuator cooling system for providing a flow of cooling air to a control valve actuator. The control valve actuator cooling system may include a pressurized air source with the flow of cooling air, an air timing valve system, and a cooling air discharge port positioned about the control valve actuator such that the air timing valve system provides the flow of cooling air to the control valve actuator on an intermittent basis.

Abstract: A turbine includes a rotor, a fluid bearing for rotatably supporting the rotor, an air supply conduit system for supplying air towards the fluid bearing, a discharge conduit system for discharging a portion of the supplied air and a control system arranged to change an amount of air discharging through the discharge conduit system based on a running condition of the turbine.

Abstract: A method and structure negating thermal inertia of a solid portion, such as shielding, which influences mechanical behavior of parts of an engine structure, by reducing forces transmitted to the engine structure during an event in which a turbine blade ruptures, while preserving mechanical strength and vibratory positioning. The structure includes a flexible fastener for a shield, enabling producing a fusible section. An assembly for mounting a shielding onto a casing of the engine structure of a turbine includes connection lugs and points for attachment to the casing and shielding. The attachment points are sufficiently spaced apart in accordance with curvature of the shielding and casing so connection between the lugs and the shielding or casing, and connection of the attachment points, are substantially tangential. The lugs are sized so the connection has sufficient flexibility to control vibratory positioning thereof and ensure sufficient mechanical strength under thermo-mechanical loads.

Abstract: A containment case for a gas turbine including: a cylindrical outer casing extending about an axis and having a radially outer and a radially inner surface; a coaxially arranged cylindrical inner skin formed of a harder material than the outer casing joined to the inner surface of the cylindrical outer casing; and an array of ribs extending radially from the inner skin towards the axis. The case for can have the coaxially arranged cylindrical inner skin formed of a harder material than the outer casing joined to the inner surface of the cylindrical outer casing by a galvanic isolation layer.

Abstract: An expansion turbine, comprising: a case having an inlet and an outlet for a working fluid; at least one stator (3) installed inside the case; at least one rotor (2) installed inside the case and rotating around a respective revolution axis (X-X); a short-pipe (4) constrained to the case; a mechanical unit (5) installed inside the short-pipe (4). The mechanical unit (5) comprises a bushing (7) and a shaft (6) rotatably installed inside the bushing (7). The shaft (6) is connected to the rotor (2) in removable manner and the whole mechanical unit (5) inclusive of the shaft (6) is extractable from the short-pipe (4) in a unitary form from the side opposite to said rotor (2).

Abstract: Various embodiments include apparatuses adapted to displace components from a location within a turbomachine. In some embodiments an apparatus for displacing a component of a gas turbine from a first slot in a spacer disk includes a body including a mounting member configured to affixedly attach to a second slot of the spacer disk, a linear actuator coupled to the body and a displacement arm coupled to the linear actuator, the displacement arm actuatable in a first axial direction by the linear actuator to contact the component and displace the component relative to the first slot.

Abstract: An acoustic damping device is provided which includes at least one opening for a sealing gas to deflect a grazing gas flow away from the mouth of an acoustic damper.

Abstract: A gasifier (101) including a fluid communication channel (131) that communicates a fluid, which undergoes heat exchange in the furnace, and that generates syngas by gasifying fuel; gas purifying equipment that removes impurities contained in the syngas generated by the gasifier (101); a gas turbine that is driven by the gas purified by the gas purifying equipment; and a heat exchanger that heats a fluid with exhaust expelled from the gas turbine. The fluid heated by the heat exchanger is supplied to the fluid communication channel (131) by being pressurized by pressurizing gas when performing warm-up of the gasifier (101).

Abstract: A supercritical heat recovery steam generator includes a duct defining an interior area and having a gas inlet and a gas outlet. The duct is configured to convey gas from the gas inlet to the gas outlet. A portion of the duct between the gas inlet and the gas outlet defines an exhaust gas flow segment of the interior area. A supercritical evaporator is disposed in the interior area and a reheater is disposed in the interior area. The reheater and the supercritical evaporator are disposed in the exhaust gas flow segment, adjacent to each other with respect to the flow of the exhaust gas.

Abstract: A method for operating a gas and steam turbine plant is provided. In the plant, the flue gas that escapes from a gas turbine is routed through a waste gas steam generator and where a flow medium that is used to drive a steam turbine is conducted in a flow medium circuit that includes several pressure stages. At least one of the pressure stages has an evaporator circuit with a steam collection drum that has a plurality of downpipes connected to the steam collection drum and a plurality of rising pipes downstream of the downpipes that are likewise connected to the steam collection drum and are heated by the flue gas in the waste heat steam generator. The height of the fluid column formed by the flow medium in the downpipes is monitored and a transient dry operation of the evaporator circuit can thus be detected and safeguarded against.

Abstract: A method for producing electrical energy is disclosed which uses a heat source, such as solar heat, geothermal heat, industrial waste heat or heat from power production processes, providing heat of 150° C. or below, further comprising an absorber system in which a working gas, primarily carbon dioxide CO2, is absorbed into an absorbent, typically an amine, further comprising a reactor which receives heat from said heat source and in which the absorbent-CO2 mixture is split into CO2 and absorbent, further comprising an expansion machine, an electricity generator and auxiliary equipment such as pumps, pipes and heat exchangers. The system according to the method allows the cost-efficient production of electrical energy and cooling using low value heat source.

Abstract: A computer-implemented method can include receiving a contact point path between a rocker arm pad and a valve tip. The method can include adjusting the contact point path to obtain a modified contact point path that satisfies a design objective of decreased valve tip wear or decreased valve tick. The method can include determining and outputting a custom contour for the rocker arm pad and the camshaft lobe based on the modified contact point path. The custom contoured camshaft lobe can companion with the custom contoured rocker arm pad to produce the modified contact point path for the specified design objective.

Abstract: A support element for the valve train of an internal combustion engine, having a hollow cylindrical housing that holds a displaceable piston. The piston has a hollow cylindrical pressure part and a pot-shaped work part axially adjacent thereto. An inner space of these parts forms a storage space for hydraulic medium. A high pressure space is defined by a base of the work part and the housing. The storage space and the high pressure space are connected hydraulically by a non-return valve with a ball for automatic lash compensation of the valve train. The piston is supported by a compression spring on the housing base, and a retaining ring is arranged radially between the pressure part and the housing, which limits axial travel of the piston. The ball is movably held in the base of the work part in an axial ball guide having first and second integrally formed ball seats.

Abstract: An intake valve actuation (IVA) system for a dual fuel engine is disclosed. The IVA system is retrofittable between the dual fuel engine and a diesel fuel engine and includes a cam lobe with a cam-profile, a rocker arm, and an IVA piston. The rocker arm has a pad surface, which includes a plane that passes through a central axis of a rocker shaft. The rocker arm is operably connected with the cam lobe and intake valves. A rotational movement of the cam lobe corresponds to switch between the open and closed positions of intake valves. The IVA piston has a face portion, which selectively abuts against the pad surface, to temporarily lock the intake valves in open position. The IVA system defines a hand-off when the face portion abuts against the pad surface. The cam-profile facilitates constant velocity of the intake valves at the hand-off.

Abstract: A camshaft phaser, including a stator (1) that can be driven via a crankshaft of an internal combustion engine, and a rotor (2) that can be non-rotatably joined to a camshaft of the internal combustion engine, and a torsion spring (5) that has helical windings and that acts between the rotor (2) and the stator (1) and whose first radially inner end (7) is directly or indirectly joined to the rotor (2), and whose second radially outer end (8) is directly or indirectly joined to the stator (1), whereby a central, axially protruding pipe section (19) associated with the rotor (2) is provided, and the first end (7) of the torsion spring (5) is non-rotatably affixed with a positive fit to the pipe section (19).

Abstract: A compression-release brake system comprises an exhaust rocker arm, an actuation piston slidable in a piston bore in the exhaust rocker arm so as to press an exhaust valve, a supply conduit formed within the exhaust rocker arm, and an exhaust valve reset device mounted to the exhaust rocker arm. The actuation piston defines an actuation piston cavity within the actuation piston bore between the piston bore and the actuation piston. The exhaust valve reset device includes a reset check valve disposed between the supply conduit and the actuation piston cavity to hydraulically lock the actuation piston cavity by closing the reset check valve when a pressure of the hydraulic fluid within the actuation piston cavity exceeds the pressure of the hydraulic fluid in the supply conduit. The reset check valve is biased closed by the pressure of the hydraulic fluid within the actuation piston cavity during the brake-on mode.

Abstract: A muffler (1) for an exhaust system of a vehicle driven by an internal combustion engine, includes a gas-tight housing (2), a partition wall (31) inside the housing, an inlet pipe (51), a first outlet pipe (61), a switchable second outlet pipe (7) and a resonator pipe (8). The a partition wall (31) divides the housing's interior into a first volume (41) and a second separate volume (42). The inlet pipe and the first outlet pipe (61) and the second outlet pipe and the resonator pipe are in fluid communication with the first volume. The resonator pipe provides fluid communication between the first volume and the second volume. The second outlet pipe passes through the second volume. The second outlet pipe is surrounded, in a circumferential direction, by the resonator pipe in a section in which the second outlet pipe penetrates the partition wall.

Abstract: A method for operating an internal combustion engine having an exhaust emission control unit with at least one exhaust emission control component which acts catalytically and/or by filtration involves operating the internal combustion engine, during a cold start or warm-up of the internal combustion engine, using a cold start engine operating process with predefined values for predefined internal combustion engine operating variables. The cold start and/or the warm-up of the internal combustion engine is controlled or regulated as a function of soot loading of a particle filter of the exhaust emission control unit.

Abstract: In a honeycomb structure, a bonding material monolithically bonds a plurality of honeycomb segments. The bonding material contains crystalline anisotropic ceramic particle and a particulate pore former. The crystalline anisotropic ceramic particle is 20 mass % or less. An average particle diameter of the pore former in the bonding material is 80 to 200 ?m. In the case where a compressive Young's modulus of the bonding material is assumed as E (unit: MPa) and a shear strength of the bonding material is assumed as ? (unit: kPa), ?/E is 5 to 50.

Abstract: Provided is a method for extending a temperature range enabling combustion of high concentration hydrocarbon, or for rapidly supplying high temperature gas to a later stage catalyst. Provided is a method for purification of exhaust gas from an internal-combustion engine comprised by: providing a temperature-raising catalyst for exhaust gas from an internal-combustion engine in an exhaust gas passage of the internal-combustion engine, along flow of said exhaust gas, at the upstream side of a purification catalyst for said exhaust gas; and introducing hydrocarbon in an amount of 1,000 to 40,000 ppm, as converted to methane, from the upstream side of the temperature-raising catalyst, wherein said temperature-raising catalyst has catalytically active components supported onto a refractory three-dimensional structure, wherein concentration of said components has a gradient such that said concentration gradually becomes lower from the inflow side toward the outflow side of said exhaust gas.

Abstract: Provided is a NOx reducing device which is capable of effectively protecting a NOx controller against heat and water, while suppressing an increase in cost of a construction machine and deterioration in assemblability of the NOx controller. The NOx reducing device comprises a device body, a tail pipe provided at an outlet end portion of the device body, a NOx controller, and a mount table supporting the device body. The mount table comprises a top plate and a leg supporting the top plate. The device body and the tail pipe are provided on an upper side of the top plate. The NOx controller is provided with respect to a lower surface of the top plate in such a manner that the NOx controller is entirely covered from thereabove by the top plate.

Abstract: An internal combustion engine which is provided with a fuel injector which injects fuel into a cylinder, an exhaust purification catalyst, and a secondary air feed device which feeds air to an engine exhaust passage. First catalyst warm-up control performs stratified combustion to retard an ignition timing, while second catalyst warm-up control feeds air to the engine exhaust passage. A first temperature range of engine cooling water at which the first catalyst warm-up control is performed and a second temperature range of engine cooling water at which the second catalyst warm-up control is performed are set. The second temperature range is set to be included inside the first temperature range.

Abstract: A selective catalytic reduction (SCR) system includes an exhaust pipe for receiving an exhaust gas from an engine. A selective catalytic reduction (SCR) unit is provided downstream of the exhaust pipe. A first mixing element including a meshed body defines a first surface, a second surface, and a plurality of openings extending from the first surface to the second surface. The first surface and second surface are parallel to each other and define an angle relative to a flow direction of the exhaust flow. The angle is less than 90 degrees.

Abstract: Various systems and methods are described for detecting ammonia slip. In one example method, an exhaust system with two NOx sensors uses transient responses of the NOx sensors to allocate tailpipe NOx sensor output to NOx and NH3 levels therein. An ammonia slip detection counter with gains is included that determines a probability of NOx and NH3 based on the measured sensor activities that are further processed by a controller to adjust one or more parameters based on the allocation and changes of sensor output.

Abstract: Reductant delivery systems are disclosed that include a dry reductant source and a liquid reductant source which are operable to selectively provide gaseous reductant and liquid reductant to an exhaust aftertreatment system for treatment and reduction of NOx emissions. The gaseous reductant is provided to the exhaust aftertreatment system for treatment of NOx emissions under a first temperature condition associated with the exhaust system and the liquid reductant for treatment of NOx emissions under a second temperature condition associated with the exhaust system.

Abstract: A method for metering reducing agent to an exhaust gas treatment device having a feed point and an SCR catalytic converter converting nitrogen oxide compounds in the exhaust gas, includes at least: a) calculating the following target conversion rates indicating what fraction of the nitrogen oxide compounds in the exhaust gas can be converted by the catalytic converter: a first rate determined from the power output of an internal combustion engine; a second rate determined from the mass flow of nitrogen oxide compounds in purified exhaust gas; and a third rate determined from a ratio of quantities of nitrogen oxide compounds upstream and downstream of the catalytic converter; b) selecting the lowest rate; c) determining the dosing quantity of reducing agent for the selected rate; and d) dosing the determined dosing quantity into the exhaust gas treatment device. An exhaust-gas treatment device and a motor vehicle are also provided.

Abstract: An example method includes interpreting an NH3 composition value at a position upstream of a selective reduction catalyst (SCR) element fluidly disposed in the exhaust conduit of an engine, interpreting a NOx composition value at a position downstream of the SCR element, and determining an NH3 sensor rationality threshold in response to the upstream NH3 composition value. The method further includes determining an NH3 sensor health value as indicating a sensor failure in response to the downstream NOx composition value exceeding the NH3 sensor rationality threshold.