Abstract: An airfoil for a turbine engine includes an airfoil that has pressure and suction sides that extend in a radial direction from a 0% span position at an inner flow path location to a 100% span position at an airfoil tip. The airfoil has a relationship between a leading edge dihedral and a span position. The leading edge dihedral is negative from the 0% span position to the 100% span position. A positive dihedral corresponds to suction side-leaning, and a negative dihedral corresponds to pressure side-leaning. The airfoil is a fan blade for a gas turbine engine. The airfoil has a relationship between a trailing edge dihedral and a span position. The trailing edge dihedral is positive from the 0% span position to the 100% span position. A positive dihedral corresponds to suction side-leaning and a negative dihedral corresponds to pressure side-leaning.

Abstract: A blade for a continuous-flow machine is disclosed, especially an aircraft engine, whereby, starting from the middle section, the cross section of the blade tip is reduced with respect to the middle section, at least over a front partial section in the direction of the leading edge and over at least a rear section in the direction of the trailing edge, and a continuous-flow machine having at least one row of blades including such blades is also disclosed.

Abstract: A wind blade is provided. The wind blade includes a body having an aerodynamic contour extended between a blade root and a blade tip. The wind blade also includes an extension tip sleeve arranged over the blade tip. The extension tip sleeve further includes a first portion having an extension blade and one or more structural ribs arranged on a pressure side of the wind blade. The extension tip sleeve also includes a second portion having a support structure located on a suction side of the wind blade. Furthermore, the wind blade includes a fairing having an airfoil shape for covering the one or more structural ribs, and the support structure of the extension tip sleeve.

Abstract: A device for damping of vibratory energy in the blades of rotor assemblies during operation where the blades have a shroud attached thereto with at least one sealing rail extending radially outward from the shroud to an outer diameter surface. A damper element is attached to the turbine blade sealing rail extending radially inward from the rail outer diameter surface along rail sides to maintain the damper element out of the flow of gas and positioned at a radial location on the blade for damping.

Abstract: A hub for mounting propeller blades has a plurality of mount locations for receiving propeller blades at a radially outer location. The hub has a piloting diameter centered on a center axis. The hub has a plurality of openings to receive a drive member for transmitting rotation/torque from an adapter. There are reliefs cut into the piloting diameter at locations circumferentially aligned with the openings.

Abstract: Described are a gas turbine engine fan blade platform, related rotor assembly and gas turbine engine, as well as a method of assembling the same. The platform has a forward portion proximal to an axis of rotation, an aft portion, and a transition portion between the forward and aft portions. The forward portion has a forward interface surface facing axially forward, the aft portion has an aft interface surface facing radially outward, and the transition portion has at least one mounting feature. For the method of assembly, an aft support is installed on a fan disk and booster spool assembly. A plurality of fan blades are installed into a fan disk, followed by installing a fan platform between adjacent blades and securing the mounting features to the disk, thereby filling the annulus of the fan disk. Finally, a forward support is installed on the fan disk.

Abstract: In a turbine for an exhaust gas turbocharger having a turbine housing which has a first and a second spiral channel with the second spiral channel extending over a wrap angle range of less than 360 degrees of a turbine wheel of the turbine, and the first spiral channel having a larger wrap angle range than the second spiral channel and the spiral channels being arranged adjacent each other in at least one angular range which includes the wrap angle ranges, the nozzle has an overall nozzle width via which exhaust gas is admitted to the turbine wheel over a respective partial nozzle width of the spiral channels wherein the partial nozzle width of the first spiral channel is greater than the partial nozzle width of the first spiral channel in the first angular range, at least in a further angular range of the wrap angle range which is different from the at least one angular range.

Abstract: A component, in particular for a gas turbine, is disclosed. The component has at least two component segments which are arranged relative to one another leaving a gap and are sealed against each other by a sealing device. The sealing device includes at least one brush seal. Also disclosed is a gas turbine, in particular an aircraft engine, having such a component.

Abstract: A seal structure partitions a high-pressure portion and a low-pressure portion including spring-back seal rings on the high-pressure side, including ACC seal rings and fins on the low-pressure side. The ACC seal rings have an adjustable movable seal ring which is a movable seal ring that is movable in a substantially radial direction at a portion thereof and which partitions a high-pressure side steam chamber and a medium-pressure side steam chamber with the fins and a circumferential surface, and including a pressure equalizing pipe that connects the low-pressure side of the adjustable movable seal ring to a high-pressure outlet portion, is provided with an adjusting pipe that connects, on the high-pressure side steam chamber side of the ACC seal rings, a high-pressure dummy to the same high-pressure outlet portion as the medium-pressure side steam chamber, and an open/close valve in the adjusting pipe.

Abstract: A circumferentially extending sealing band is located within sealing band receiving slots formed in adjacent turbine engine disks. The sealing band includes a plurality of seal strips forming overlap joints defined by overlapping end portions, each formed by a tongue portion extending from a seal face of one seal strip past a seal face of the adjacent seal strip, along a radially inward facing side of the adjacent seal strip. A joint gap is defined within at least one overlap joint between the seal face of the one seal strip and the seal face of the adjacent strip, and a spacer is affixed to the one seal strip and is located at a position within the joint gap between the seal faces to limit circumferential movement of the seal faces toward each other.

Abstract: An apparatus for a gas turbine power plant that uniquely configures emission control equipment such that the plant can extend the emissions compliant operational range, the apparatus including a plurality of oxidation (CO) catalysts arranged in series, optimized SCR for high NO2 reduction, Control valves with added capabilities for low turndown and other characteristics.

Abstract: A steam power plant is suggested having, parallel to the low-pressure passage (VW1 to VW2), a heat reservoir (A) which is loaded with preheated condensate in weak-load times. This preheated condensate is taken from the heat reservoir (A) for generating peak-load and inserted downstream of the low-pressure preheater passage (VW1 to VW2) into the condensate line that contacts the feed water container (8). Thus it is possible to quickly control the power generation of the power plant in a wide range without significantly having to change the heating output of the boiler of the steam generator (1). A steam power plant equipped according to the invention can thus be operated with bigger load modifications and also provide more control energy.

Abstract: A steam turbine plant of one embodiment includes a boiler to change water into steam, a high pressure turbine including plural stages of rotor and stator vanes and to be driven by the steam from the boiler, a reheater to heat the steam from the high pressure turbine, a reheat turbine including plural stages of rotor and stator vanes and to be driven by the steam from the reheater, a condenser to change the steam from the reheat turbine into water, a collector to collect water from, for example, the steam existing upstream of an inlet of the final-stage rotor vane in the high pressure turbine, and a path to cause collected matter in the collector to flow into, for example, the steam between an outlet of the final-stage rotor vane of the high pressure turbine and an inlet of the final-stage rotor vane of the reheat turbine.

Abstract: An ORC heat engine including a working fluid circuit having an evaporator for heating and evaporating a working fluid, a condenser for cooling and condensing the working fluid, and a positive displacement expander-generator having an inlet in fluid communication with the evaporator and an outlet in fluid communication with the condenser. The ORC heat engine further includes a control system coupled to the positive displacement expander-generator having a switch and driving means, the switch being switchable between a first state and a second state, wherein in the first state the switch is coupled to the driving means, and the positive displacement expander-generator is drivable by the driving means, and in the second state the switch is not coupled to the driving means or the driving means is switched off, and the positive displacement expander-generator is not drivable by the driving means.

Abstract: Cogeneration method, according to which a hot source (2) produces steam that is released in at least one turbine (3) having a low-pressure steam outlet (5) linked to a condenser; at least a fraction (Q) of the steam leaving the turbine (3) is directed towards a Venturi thermocompressor (14) into which a fluid having higher pressure and temperature than the outgoing steam is injected, resulting in a fluid having higher pressure and temperature than the outgoing steam, and this mixture is directed towards a second condenser (21) where the heat of the mixture is transferred to an auxiliary fluid of a circuit (23) external to the thermodynamic cycle.

Abstract: A variable valve device for varying a lift amount of a valve includes a first valve and a second valve that are respectively disposed to open or close a port, a swing arm in which first and second valve pressing portions are formed at both sides to press the first valve and the second valve, one supporting portion that supports a part that is apart from the first and the second valve pressing portions on the swing arm, a lost body that is rotatably disposed on the swing arm through a lost pin, a camshaft on which a first cam and a second cam are formed to respectively press the lost body and the swing arm, and a latching pin that selectively fixes the swing arm with the lost body and is disposed to move in a direction that the first and the second valves are arranged.

Abstract: A valve assembly includes a valve having a head and a stem. The head is configured to seal against a valve seat. The stem has a distal end. A first piston radially extends from the stem of the valve and is enclosed within a housing. A second piston is fixed to the distal end of the stem and seals against the housing. A first chamber is defined by the first piston, second piston and the housing and receives a compressed gas and maintains a desired gas pressure. A spring device is disposed intermediate the first piston and the housing. During normal operation of the engine, the gas pressure within the first chamber seals the head of the valve against the valve seat with the spring device in a compressed arrangement and wherein during periods of insufficient gas pressure the spring device biases the valve to seal against the valve seat.

Abstract: An unmanned aerial vehicle (UAV) engine (40) lubrication system and lubrication oil heating strategy uses a solenoid actuated electric oil pump (10,42) to deliver lubrication oil to the engine from a lubrication oil reservoir (12,44) by energizing and de-energizing the solenoid (18) to operate a pump mechanism of the electric oil pump. A controller (ECU) (100) can control operation of the electric oil pump, the solenoid maintained energized for a required period of time to cause heating of the oil without continuously pumping the oil. An electric oil pump control strategy can maintain engine speed dependent minimum oil delivery rates, can heat the electric oil pump and oil through extended energized (ON) time of the solenoid, and, by varying the turn on time of the electronic oil pump based on sensed ambient temperature, long time periods can be used to ensure oil delivery for cold temperatures, and shorter times are permitted when necessary in order to reach maximum oil flow rate.

Abstract: In an oil pan inner tank valve structure, a disc-shaped float valve is arranged below a valve port that provides fluid communication between the inside and outside of a bottom wall of an inner tank, and a lower cover is arranged below the float valve. In addition, a center recess is depressed at a lower surface center of the float valve, and a lateral movement restricting pin is upright from the lower cover and is constantly engaged with the center recess by recess/protrusion engagement. The lower cover restricts a vertically movable range of the float valve. In addition, the lateral movement restricting pin restricts lateral movement of the float valve so that a top portion of an upper surface bulged portion vertically constantly faces an area inside a valve seat.

Abstract: An exhaust apparatus includes: an inner tube including therein an exhaust passage and also including a peripheral wall portion on which a plurality of opening portions communicating with the exhaust passage are formed; an outer tube accommodating the inner tube, an internal space being formed between the outer tube and an outer periphery of the inner tube; and a flow rectifying member arranged at a region inside the inner tube, having a spiral shape in an axial direction of the inner tube, and configured to rectify an exhaust gas flowing through the exhaust passage.

Abstract: An operating method of an exhaust gas aftertreatment system including at least a particulate filter for retaining soot from the exhaust gas of an engine and a deNOx catalytic converter for reducing nitrogen oxide in the exhaust gas of the engine is provided. Operation regimes of the particulate filter and of the deNOx catalytic converter are synchronized with respect to each other for performing regeneration of the particulate filter while the catalytic converter provides a nitrogen oxide conversion efficiency above a predetermined limit.

Abstract: An exhaust gas treatment device (1) includes a combustion waste gas inlet pipe (2), an outlet pipe, an essentially gas-tight inner housing (7) fluidically connected with the inlet pipe and fluidically connected with the outlet pipe. The inner housing receives a particle filter (4). A connection element (9) is arranged in a connection area (8) of the inner housing. The connection area fluidically faces the outlet pipe (3), for mechanically connecting the particle filter with the inner housing. An oxidation catalytic converter (5) is arranged upstream of the particle filter in the inner housing for catalyzing an oxidation reaction of the combustion waste gas. A counterpressure monitoring point (10, 11, 12) is provided fluidically between the oxidation catalytic converter and the connection element for measuring a counterpressure exerted by the particle filter during the operation of the treatment device. An internal combustion engine (24) is provided with the treatment device.

Abstract: A combustion exhaust gas treatment system comprising: a heat exchanger (A) for recovering heat contained in the combustion exhaust gas into heat medium, an absorption column for obtaining CO2 removed gas by absorbing CO2 in the combustion exhaust gas into absorbent, a heat exchanger (B) for applying heat recovered by heat medium to the CO2 absorbed absorbent, a desorption column for desorbing the absorbent by removing CO2 from the CO2 absorbed absorbent, a flash tank for flash vaporizing the desorbed absorbent and a heat exchanger (E) for transferring heat from the desorbed absorbent to the CO2 absorbed absorbent, wherein the CO2 absorbed absorbent can be supplied from the absorption column to the desorption column via the heat exchanger (E) and the heat exchanger (B) in this order, and the desorbed absorbent can be supplied from the desorption column to the absorption column via the flash tank and the heat exchanger (E) in this order.

Abstract: A method pertaining to an SCR system for cleaning of exhaust gases from an engine including a dosing unit (250) to supply a reducing agent to an exhaust duct (240): Determining (s340) whether there is an undesired temperature level of the dosing unit (250). If one is found, removing (s360) warmed reducing agent from the dosing unit (250) and supplying it to the exhaust duct (240). Calculating (s350) and removing an amount of reducing agent based on a prevailing temperature of the dosing unit (250), or removing warmed reducing agent. Also a computer program product containing program code (P) for a computer (200; 210) for implementing the method. Also a device of an SCR system and a motor vehicle (100) which is equipped with the device are disclosed.

Abstract: A system for exhaust gas treatment for internal combustion engines has a pump (1) for metered supply of a freezable substance, particularly a urea solution, to a supply device (23) introducing the substance into the exhaust gas flow. A compensation device (25) is provided as protection against damage to the system due to volume expansion when the substance freezes. The compensation device compensates for the volume expansion accompanying an increase of the fluid pressure when the substance freezes.

Abstract: A method for diagnosing reductant delivery performance of a reductant delivery system is provided. The method provides an outlet pressure sensor at a reductant outlet of the reductant delivery system and a virtual pressure sensor in an exhaust stream where reductant is injected into the stream. The method comprises calculating a downstream reductant flow rate using the outlet pressure sensor and the virtual pressure sensor; and calculating an upstream reductant flow rate within the reductant delivery system using at least one of a temperature sensor, a pressure sensor and a control valve. The calculated downstream and upstream reductant flow rates are compared, and diagnostics is conducted based the comparison to find the malfunctions in the reductant delivery system. An intrusive self-consistent diagnostics method allows for detection of malfunctions in the outlet pressure sensor and the virtual pressure sensor can be determined.

Abstract: Methods and systems are provided for determining degradation of a particulate filter in an exhaust conduit. In one example, a method may include diverting exhaust gas to a secondary flow assembly comprising a filter and determining degradation based on time intervals between subsequent filter regenerations of the filter in the secondary flow assembly.

Abstract: Provided is a control device for a multi-cylinder internal combustion engine, including: a supercharger to be driven by exhaust gas energy; and a fuel injection control unit, in which the fuel injection control unit sets a fuel injection amount for one cylinder so that an air/fuel ratio in the one cylinder is richer than a theoretical air/fuel ratio, and exhaust gas exhausted when the one cylinder is in an exhaust stroke and scavenging gas scavenged during a valve overlap period from another cylinder which is in an intake stroke when the one cylinder is in the exhaust stroke are mixed in an exhaust pipe so as to attain an air/fuel ratio facilitating combustion.

Abstract: When alcohol-blended fuel is supplied to an internal-combustion engine, the magnitude of alcohol concentration (more particularly, ethanol concentration Cetha) is judged (Step 1005) and, based on this judgment, the magnitude of operational status temperature (more particularly, cooling water temperature THW) is judged (Step 1015). Then, when the alcohol concentration is large and the operational status temperature is low, generation of an intermediate product which is an oxide of alcohol contained in the alcohol-blended fuel in an unburnt state after main injection and alcohol contained in the alcohol-blended fuel in an unburnt state after post injection (more particularly, aldehyde) is promoted, and the generated intermediate product is trapped in an intake passage by making an intake valve into an opened state in an exhaust stroke of the internal-combustion engine (Step 1055).

Abstract: A portable on-demand hydrogen supplemental system is provided for producing hydrogen gas and injecting the hydrogen gas into the air intake of internal combustion engines. Hydrogen and oxygen is produced by a fuel cell from nonelectrolyte water in a nonelectrolyte water tank. The hydrogen gas is passed through a hydrogen gas collector. Nonelectrolyte water mixed with the hydrogen gas in the hydrogen gas collector is passed back thru the tank for distribution and water preservation. The system can be powered by the vehicles alternator, a stand-alone battery, waste heat or solar energy. The system utilizes an onboard diagnostic (OBD) interface in communication with the vehicle's OBD terminal, to regulate power to the system so that hydrogen production for the engine only occurs when the engine is running. The hydrogen gas is produced it is immediately consumed by the engine. No hydrogen is stored on, in or around the vehicle.

Abstract: An internal combustion engine with at least two rotatable bodies each defining at least one combustion chamber of variable volume and, for each rotatable body: a pilot subchamber, a pilot fuel injector having a tip in communication with the pilot subchamber, an ignition element positioned to ignite fuel within the pilot subchamber, and a main fuel injector spaced apart from the pilot fuel injector. The engine includes a common first fuel conduit in fluid communication with each main fuel injector, and a common second fuel conduit in fluid communication with each pilot fuel injector. First and second pressure regulating mechanisms which are settable at different pressure values from one another respectively regulate a fuel pressure in the first and second conduits. A method of combusting fuel in an internal combustion engine is also provided.

Abstract: An aggregate, in particular a hybrid engine, electrical power generator or compressor, comprises a housing in which are arranged a piston motor part and an electric motor part, wherein the piston motor part has a first piston with a first end face and at least one second piston with a second end face, wherein the first piston and the at least one second piston perform reciprocating motions, wherein between the first end face and the second end face is provided a working chamber for a working medium, which chamber is periodically reduced and enlarged because of the reciprocating motions of the pistons, and wherein the electric motor part has an annular rotor which can rotate in the housing about a rotation axis that is fixed relative to the housing. The rotor surrounds the piston motor part.

Abstract: In one embodiment, a turbine using CO2 includes moving blades, stator blades, a working fluid transport flow path, a coolant transport flow path, and a coolant recovery flow path. The stator blades constitute turbine stages together with the moving blades. The working fluid transport flow path is configured to transport the working fluid sequentially to the turbine stages. The coolant transport flow path is configured to transport the coolant by allowing the coolant to sequentially pass through the inside of the stator blades from an upstream to a downstream of the working fluid. The coolant recovery flow path is configured to recover the coolant passing through the inside of the stator blade at a predetermined turbine stage and merge the recovered coolant with the working fluid transport flow path at a turbine stage on an upstream side of the predetermined turbine stage.

Abstract: The present techniques are directed to a combustor for a gas turbine. For example, an embodiment provides a spool piece for the combustor. The spool piece includes an oxidant injection port configured for injection of an oxidant proximate to a flame in the combustor and a recycle-gas extraction port configured for an extraction of a recycle gas from the combustor, wherein the recycle gas is isolated from the oxidant prior to the use of the oxidant in a flame.

Abstract: Louver systems for gas turbine bleed air systems are disclosed. An example louver system may include a bleed system discharge opening arranged to vent bleed air from a bleed flow conduit and a plurality of pivotable louvers disposed proximate the discharge opening, the pivotable louvers being pivotable between a shut position and an open position. In the shut position, individual louvers may at least partially obstruct the discharge opening. In the open position, individual louvers may at least partially control a direction of flow of the bleed air exiting the discharge opening.

Abstract: A method for assembling a nozzle and an exhaust case of a turbomachine is disclosed. The exhaust case includes a hub and an outer ferrule connected to each other by a plurality of arms. The nozzle is attached to the outer ferrule of the exhaust case substantially at the trailing edges of the arms.

Abstract: A pump sharing valve for a gas turbine engine fuel system includes a housing having multiple ports. A sleeve is arranged in the housing and includes an inlet window and first, second and third windows axially spaced apart from one another. A spool is slidably received in the sleeve and includes a diameter and first and second cylindrical portions. The first cylindrical portion selectively connects the inlet window to the second and third windows. The second cylindrical portion selectively connects the inlet window to the first window. The spool is movable between first and second positions relative to the first, second and third windows to regulate flow. The first and second cylindrical portions respectively includes first and second widths. A first ratio corresponds to the first width to the spool diameter and a second ratio corresponds to the second width to the spool diameters. The first ratio is between 1.83 and 1.93 and the second ratio is between 1.22 and 1.32.

Abstract: An ignition exciter system for igniting fuel in a gas turbine engine. The ignition exciter system includes a rechargeable energy source, at least one pulse-forming network coupled to the rechargeable energy source and generating a stored energy waveform from energy in the rechargeable energy source, at least one igniter plug coupled to the at least one pulse-forming network to receive the stored energy waveform and generating a spark in response to the received stored energy waveform.

Abstract: A method and apparatus for local loop closure is provided. The apparatus includes a component for use in a gas turbine engine. The component includes at least one of an actuator and a servo-valve, at least one sensor, and an electronic module comprising controller electronics and memory. The electronic module is configured to receive and process commands for the at least one of an actuator and a servo-valve and queue received commands in an input buffer.

Abstract: An engine control system includes a mean effective pressure (MEP) module, an imbalance module, and a phaser control module. The MEP module determines MEPs for combustion cycles of cylinders, respectively, of an engine. The imbalance module selectively determines whether first and second banks of the cylinders are imbalanced based on the MEPs. When the first and second banks of cylinders are imbalanced, the phaser control module selectively adjusts at least one of: a first phaser of an intake camshaft of the second bank of cylinders; and a second phaser of an exhaust camshaft of the second bank of cylinders.

Abstract: A variable intake air device forms a long port and a short port in each of branches of an intake air manifold. The variable intake air device switches between the long port and the short port. A gas introduction device draws gas into each of the branches. When the engine is in a high load region, the variable intake air device uses the long port, when an engine rotation speed is less than a predetermined rotation speed, and uses the short port, when the engine rotation speed is greater than or equal to the predetermined rotation speed. When the engine is in a low load region, the variable intake air device switches between the long port and the short port according to the engine rotation speed.

Abstract: To accurately specify an EGR rate from an output value of an in-cylinder pressure sensor, a specifying method of an EGR rate in an internal combustion engine of the present invention acquires an output value of an in-cylinder pressure sensor at an intake stroke to calculate comparison data related to an in-cylinder pressure at the intake stroke from the acquired sensor output value. An output value of the in-cylinder pressure sensor at an exhaust stroke of the same cycle is also acquired to calculate comparison data related to the in-cylinder pressure at the exhaust stroke from the acquired sensor output value. Two comparison data are compared to specify the EGR rate of an air-fuel mixture provided for combustion from a difference between the values.

Abstract: A system according to the principles of the present disclosure includes a desired capacity module, an anticipated torque request module, and an engine actuator module. The desired capacity module generates a desired torque capacity of an engine at a future time based on a present torque request and a maximum torque output of the engine. The anticipated torque request module generates an anticipated torque request based on the desired torque capacity. The engine actuator module controls an actuator of the engine at a present time based on the anticipated torque request.

Abstract: A road surface slope estimating device includes a forward/backward sensor that outputs a detected forward/backward of a vehicle, a forward/backward estimator that calculates an estimated forward/backward of the vehicle, and a road surface slope estimating device that calculates an estimated road surface slope value using the detected forward/backward and the estimated forward/backward. The road surface slope estimating device implements a momentarily rough terrain determination step to determine whether the vehicle is traveling on momentarily rough terrain or continuously rough terrain. When it is determined that the vehicle is traveling on momentarily rough terrain, the road surface slope estimating device fixes the estimated road surface slope value to an estimated road surface slope value obtained immediately before the determination is made.

Abstract: Air/fuel imbalance monitoring systems and methods for monitoring air/fuel ratio imbalance of an internal combustion engine are disclosed. In one embodiment, adjusting engine operation responsive to cylinder air/fuel imbalance based on a determined total number of instances where sensed peak-to-peak exhaust air-fuel ratios differentials are less than a threshold normalized to a total number of peak-to-peak oscillations. The approach can be used to indicate air/fuel ratio imbalances between engine cylinders.

Abstract: A method for determining cylinder blow-through air via engine volumetric efficiency is disclosed. In one example, the method provides a way to adjust cylinder blow-through to promote and control a reaction in an exhaust after treatment device. The approach may simplify cylinder blow-through calculations and improve engine emissions via providing improved control of constituents reaching an exhaust after treatment device.

Abstract: A variety of methods and arrangements for detecting misfire in a skip fire engine control system are described. In one aspect, a window is assigned to a target firing opportunity for a target working chamber. A change in an engine parameter is measured during the window. A determination is made as to whether a firing opportunity before the target firing opportunity is a skip or a fire and/or whether a firing opportunity after the target firing opportunity is a skip or a fire. Based at least in part on this skip/fire determination, a determination is made as to whether the target working chamber has misfired. In various embodiments, if the target working chamber is identified as persistently misfiring, the firing sequence is modified so that the target working chamber is deactivated and excluded from the firing sequence. In still other embodiments, a torque model is used to detect engine-related problems.

Abstract: In one aspect, a method for controlling operation of an internal combustion engine is described. The engine is operated in a skip fire manner such that selected skipped working cycles are skipped and selected active working cycles are fired to deliver a desired engine output. A particular level of torque output is selected for each of the fired working chambers. Various methods, arrangements and systems related to the above method are also described.

Abstract: A system includes a controller configured to compare a nitrogen oxides (NOX) concentration within treated exhaust gases from a combustion engine after flowing through a first catalyst assembly and a second catalyst assembly relative to a NOX threshold value, to determine a change in O2 concentration within the treated exhaust gases between the first and second catalyst assemblies upstream of a location of oxidant injection into the treated exhaust gases, and to adjust an air-fuel ratio of the combustion engine based on the change in O2 concentration in the treated exhaust gases if the NOX concentration is greater than the NOX threshold value.

Abstract: An ECU for controlling an engine counts an unused time TIM of engine in a low-temperature environment. If the unused time TIM is shorter than a predetermined reference value, the ECU sets idle speed immediately after start of operation of the engine to a first idle speed, and if the unused time TIM is longer than the reference value, sets the idle speed to a second idle speed higher than the first idle speed. If duration of the second idle speed exceeds a reference period determined by state of driving of the vehicle, the ECU sets the idle speed to be lower than the second idle speed. In this manner, increased vibration in idling operation in a low-temperature environment can be prevented.