Abstract: A gas turbine includes a combustor that can combust fuel, which can be heated by a heater, by mixing the fuel with compressed air generated by a compressor. The compressor includes an inlet guide vane for adjusting an amount of intake air. When a deviation between the temperature of the fuel at an outlet section of the heater and a set temperature of the heater exceeds a threshold value, the gas turbine control device controls the opening degree of the inlet guide vane to become larger than the opening degree when the deviation is equal to or smaller than the threshold value.

Abstract: A method of operating a gas turbine engine comprising an engine core comprising a turbine, a compressor, a combustor arranged to combust a fuel, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core; a gearbox that receives an input from the core shaft and outputs drive to the fan; an oil loop system arranged to supply oil to the gearbox; and a heat exchange system comprising an air-oil heat exchanger through which the oil flows, a fuel-oil heat exchanger through which the oil and the fuel flow; and a valve arranged to allow a proportion of the oil sent via at least one of the heat exchangers to be varied, is disclosed, the method comprising controlling the valve such that, under cruise conditions, an oil flow ratio of: rate ? of ? oil ? flow ? into ? air - oil ? heat ? exchanger rate ? of ? oil ? flow ? into ? fuel - oil ? heat ? exchanger is in the range from 0 to 0.59.

Abstract: A hybrid electric engine control module (ECU) configured to be operatively connected to a hybrid electric aircraft powerplant having a heat engine system and an electric motor system to control a torque output from each of the heat engine system and the electric motor system. The ECU can be configured to receive a torque command and split output power between the electric motor system and the heat engine system. Additionally and/or alternatively, the ECU can be configured to balance a total torque against a second total torque of a second aircraft powerplant.

Abstract: A method of and system for operating a hybrid electric propulsion system for an aircraft in a start sequence is provided. The hybrid electric propulsion system includes a thermal engine, an electric motor, a gearbox, an electric power storage unit, and a propulsion unit having a propeller having propeller blades. The method includes: driving the propeller from a static state to a target rotational speed within a predetermined range of speeds using the electric motor; transitioning the propeller blades from a feathered mode to an unfeathered mode while the propeller is being driven at the target rotational speed solely by the electric motor; starting the thermal engine; and transitioning the driving of the propeller using the electric motor to driving the propeller using the thermal engine.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed to illustrate a clearance design process and strategy with CCA-ACC optimization for exhaust gas temperature (EGT) and performance improvement. In some examples, an apparatus includes a case surrounding at least part of a turbine engine, the at least part of the turbine engine including a turbine or a compressor. The apparatus further includes a first source to obtain external air; a second source to obtain cooled cooling air; a heat exchanger to control temperature of cooled cooling air; and a case cooler to provide active clearance control air to the case to control deflection of the case, wherein the active clearance control air is a combination of the external air and the cooled cooling air, the case cooler coupled to the heat exchanger using a first valve, the first valve triggered by a first control signal.

Abstract: A system includes a burn flow line and a flow divider valve in fluid communication with the burn flow line to split flow from the burn flow line to a primary line and to a secondary line for supplying fuel to a set of primary engine nozzles and to a set of secondary engine nozzles, respectively. A sensor operatively connected to the flow divider valve to produce a feedback signal indicative of flow split between the primary line and the secondary line. A controller is operatively connected to receive the feedback signal from the senor, compare the feedback signal to a stored flow split value for a mismatch, and output an alert message upon detecting the mismatch.

Abstract: A turbine engine for an aircraft. The turbine engine includes a fan, a combustor in a core air flowpath that generates combustion gases, a core shaft, a turbine that receives the combustion gases to rotate the turbine, and a steam system. The steam system extracts water from the combustion gases, vaporizes the water to generate steam, and injects the steam into the core air flowpath. The steam system includes one or more water storage devices that store the water therein. The one or more water storage devices include a first state in which the one or more water storage devices increase or maintain a level of the water as the water flows through the one or more water storage devices, and a second state in which the one or more water storage devices decrease the level of the water in the one or more water storage devices.

Abstract: The method can include monitoring a current value of a rate of reduction of rotation speed of the shaft; providing a threshold value of a rate of reduction of rotation speed of the shaft; and generating a signal indicative of the shaft shear event when the current value exceeds threshold value.

Abstract: A gas turbine engine includes a propulsor having blades extending from a propulsor hub. A compressor section includes a first compressor and a second compressor. A speed reduction device includes an epicyclic gear system. The epicyclic gear system includes a sun gear, a plurality of intermediate gears, a carrier supporting the intermediate gears and the propulsor hub, and a ring gear. A turbine section includes a first turbine and a second turbine. The second turbine drives the propulsor through the epicyclic gear system. The epicyclic gear system is straddled by forward and aft bearings that engage the carrier.

Abstract: A hybrid electric propulsion system includes a gas turbine engine having at least one compressor section and at least one turbine section operably coupled to a shaft. The hybrid electric propulsion system includes an electric motor configured to augment rotational power of the shaft of the gas turbine engine. A controller is operable to determine hybrid electric propulsion system parameters based on a composite system model and sensor data, determine a prediction based on the hybrid electric propulsion system parameters and the composite system model, determine a model predictive control optimization for a plurality of hybrid electric system control effectors based on the prediction using a plurality of reduced-order partitions of the composite system model, and actuate the hybrid electric system control effectors based on the model predictive control optimization.

Abstract: A plant for energy storage, comprises: a basin (2) for a work fluid having a critical temperature (Tc) lower than 0°; a tank (3) configured to store the work fluid in at least partly liquid or super-critical phase with a storage temperature (Ts) close to the critical temperature (Tc); an expander (4); a compressor (5); an operating/drive machine (6) operatively connected to the expander (4) and to the compressor (5); a thermal store (8) operatively interposed between the compressor (5) and the tank (3) and between the tank (3) and the expander (4). The plant (1) is configured for actuating a Cyclic Thermodynamic Transformation (TTC) with the work fluid, first in a storage configuration and then in a discharge configuration. The thermal store (8), in the storage configuration, is configured for absorbing sensible heat and subsequently latent heat from the work fluid and, in the discharge configuration, it is configured for transferring latent heat and subsequently sensible heat to the work fluid.

Abstract: In accordance with at least one aspect of this disclosure, there is provided a fuel control system for gaseous fuel in an aircraft. The system includes a control module operatively connected to a metering device in a fuel flow conduit, the control module operable to control the flow of fuel through the fuel flow conduit. The control module includes an input line operable to receive a command input indicative of a requested engine state. In embodiments, the control module includes a compressibility logic and machine readable instructions. The machine readable instruction can be configured to cause the control module to control the metering device to achieve the requested engine state based on a compressibility factor input from the compressibility logic.

Abstract: An engine controller may include a processor and a feedback interface electrically coupled to the processor and one or more electric machine motor generators deployed in an aircraft engine. A memory, electrically coupled to the processor, is configured to store reference data used to indicate a presence of an icing condition. The processor is configured to monitor a feedback signal received at the feedback interface from the one or more electric machine motor generators and identify whether the feedback signal indicates that the icing condition is currently present in the aircraft engine based on a correspondence between the feedback signal and the reference data. The processor is configured to initiate an icing condition mitigation action in response to identifying that the icing condition is present.

Abstract: A dispatch advisor for operating a power plant having at least one gas turbine with flexibility is described. The dispatch advisor can generate a representation of a flexible base load map for operating the power plant. The representation can include an aggregation of a primary base load operating space and an expanded portion of the base load operating space. The representation offers a range of operating values for operational parameters of the power plant during base load at various base load settings at predetermined ambient conditions and corresponding power output and efficiency values that are attained while operating the power plant at the range of operating values. This offers an operator of the power plant with flexibility in controlling the plant during base load.

Abstract: A computer-implemented method comprising: controlling input of data quantifying damage received by a compressor of a gas turbine engine into a first machine learning algorithm; receiving data quantifying a first operating parameter of the compressor as an output of the first machine learning algorithm; and determining operability of the compressor by comparing the received data quantifying the first operating parameter of the compressor with a threshold.

Abstract: A hydrogen-fuelled aircraft power system incorporates a gas turbine engine and a fuel cell, in which air supply and cooling of the fuel cell is integrated with the gas turbine engine to improve overall efficiency of the power system. The system may be part of a turbofan, turboprop or electric propulsion system for an aircraft.

Abstract: A method of operating a gas turbine engine is provided. The method includes: providing a flow of a primary fuel to a combustor of a turbomachine, the turbomachine including a compressor, a turbine, and a spool rotatable with the compressor and the turbine; receiving data indicative of a spool parameter of the spool; and modifying a flow of a secondary fuel to the combustor in response to the received data indicative of the spool parameter of the spool.

Abstract: An aircraft propulsion system comprises first and second thrust producing gas turbine engines. The system comprises a controller configured to determine a required overall propulsion system thrust level, and determine an engine core power level contribution from each aircraft gas turbine engine such that the overall propulsion system produces a minimum overall noise level and meets the required overall propulsion system thrust level. In meeting the minimum overall noise level, at least the first and second gas turbine engines are operated at different engine core power settings.

Abstract: A method for tuning a gas turbine engine includes performing a sensitivity step process on a tuning parameter. An operating parameter is monitored. The gas turbine is operating in a first operational state and the operating parameter has an initial condition. The tuning parameter is selected for adjustment. The tuning parameter is adjusted by a predefined amount. The adjustment includes applying an incremental bias adjustment to a fuel flow fraction schedule. The gas turbine engine transitions to a second operational state, wherein the operating parameter has an adjusted condition. The adjusted condition and the initial condition of the operating parameter are applied to a cost function. It is then determined that the cost function results in a cost function value indicative of a decreased cost. The incremental bias adjustment and the cost function value is written to a bias look-up table and are associated with the selected tuning parameter.

Abstract: This steam turbine plant comprises: a boiler; a steam turbine; a condenser; a condensate pump; a main steam line that is capable of guiding, to the steam turbine, steam generated in the boiler; a bypass line that is branched from the main steam line and is connected to the condenser; a condensate line that is capable of guiding, to the condensate pump, water in the condenser; a condensate outlet valve that is provided in the condensate line; a water supply line that is capable of guiding, to the boiler, water having a pressure which has been increased in the condensate pump; a first connection unit that is, in the condensate line, branched from a position which is closer to the condenser than the condensate outlet valve is; and a second connection unit that is, in the condensate line, branched from a position which is closer to the condensate pump than the condensate outlet valve is. The first connection unit has a first connection seating that is connectable with a first line.

Abstract: In a closed system that recirculates exhaust gas from a gas turbine engine, recirculated exhaust gas should be mixed into inlet gas in a manner that produces a uniform distribution within the mixed gas, while preventing an excessive pressure drop at the point of mixing, and without needing excessive duct length. Otherwise, the performance of the gas turbine engine may be detrimentally affected. Accordingly, a mixer box is disclosed that injects recirculated exhaust gas into a flow path of inlet gas in a uniform manner. The mixer box may comprise mixer(s) that extend the flow path of the recirculated exhaust gas into the flow path of the inlet gas along two axes. Each mixer may comprise surface apertures and/or interior channels designed to promote uniform ejection of the recirculated exhaust gas from the mixers into the flow path of inlet gas.

Abstract: Power device based on alkali-water reaction, having a reaction chamber to carry out a chemical reaction between water and alkali element, having an exhaust nozzle to exhaust the reaction products generated in the reaction chamber, with a siphon tube connected to the exhaust nozzle, a nozzle shutter plate sealing the exhaust nozzle, and an external pressure inlet. The device has a water reservoir to store transfer water to the reaction chamber and an alkali reservoir to store and transfer an alkali element to the reaction chamber, and transfer device connecting the reaction chamber to both reservoirs to transmit the pressure generated in reaction chamber by part of the reaction products to the reservoirs, providing the transfer of water and alkali element from both reservoirs to the reaction chamber.

Abstract: A gas turbine engine fuel supply system can include a fuel delivery system, a thermal management system, a fuel manifold, and one or more sensors that identify one or more fuel parameters. A fuel control system adjusts parameters of the fuel based on data received from the sensors.

Abstract: A gas turbine engine includes a compressor rotor shaft assembly, an accessory gearbox, and a bowed-rotor mitigation drive device drivingly coupled with the accessory gearbox. The bowed-rotor mitigation drive device is driven during an engine startup phase so as to induce a mechanical load (mechanical energy) to the bowed-rotor mitigation drive device. The mechanical load (mechanical energy) is retained within the bowed-rotor mitigation drive device during operation of the gas turbine engine. The mechanical load (mechanical energy) retained within the bowed-rotor mitigation drive device is periodically released by the bowed-rotor mitigation drive device in a plurality of periods so as to provide, in each period, a driving force to the accessory gearbox, which provides the driving force to the compressor rotor shaft assembly to periodically rotate the compressor rotor shaft assembly.

Abstract: A controller for a gas turbine arranged to supply a load is described. The gas turbine includes a fuel supply arranged to supply fuel at a fuel flow rate to a combustor. The fuel supply includes a first fuel supply and a second fuel supply. The controller is arranged to control a proportion of the fuel flow rate supplied via the first fuel supply based, at least in part, on the fuel flow rate. A gas turbine includes such a controller and a method controls such a gas turbine.

Abstract: Clearance control schemes for controlling a clearance defined between a first component and a second component of a gas turbine engine are provided. In one aspect, an engine controller of the gas turbine engine implements a clearance control scheme, which includes receiving data indicating a clearance between the first component and the second component, the clearance being at least one of a measured clearance captured by a sensor and a predicted clearance specific to the gas turbine engine at that point in time; comparing the clearance to an allowable clearance; determining a clearance setpoint for a clearance adjustment system based on a clearance difference determined by comparing the clearance to the allowable clearance; and causing the clearance adjustment system to adjust the clearance to the allowable clearance based on the clearance setpoint.

Abstract: A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool, a high speed spool, and a combustor; a lubrication circuit comprising a bearing compartment, a supply pump, and a scavenger pump; an electric motor configured to augment rotational power of the low speed spool or the high speed spool; and a controller operable to: control the electric motor based upon a pressure differential between an interior of the bearing compartment and an exterior of the bearing compartment and to drive rotation of the low speed spool and/or the high speed spool via the electric motor responsive to a thrust command while fuel flow to the combustor is inhibited.

Abstract: There are describes methods and systems for operating an engine coupled to a fuel system having a fuel manifold configured to supply fuel to a combustor of the engine. The method comprises receiving a gaseous fuel flow request indicative of a change in demand for gaseous fuel to the engine; applying a fuel loss bias to the gaseous fuel flow request to obtain a biased fuel flow request, the fuel loss bias associated with a change in mass flow rate of the gaseous fuel from the fuel manifold to the combustor in response to the change in demand; and causing the gaseous fuel to flow into the combustor in accordance with the biased fuel flow request.

Abstract: A controller for a gas turbine, wherein the gas turbine includes the compressor arranged to operate at a rotational speed n, the combustor and the fuel supply including the first fuel supply and the second fuel supply, wherein the compressor is arranged to provide air to the combustor at a steady state air mass flow rate mss and wherein the fuel supply is arranged to supply fuel at a fuel mass flow rate mtotal to the combustor. The controller is arranged to, responsive to a load change ?L to the load L, control the compressor to provide air to the combustor at a new air mass flow rate mTR, wherein the new air mass flow rate mTR is within a range between a first threshold mLBO and a second threshold mSUR.

Abstract: An aircraft hybrid propulsion system comprises an internal combustion engine, an electric motor a propulsor and a combining gearbox. The internal combustion engine is coupled to a first input of the combining gearbox, the electric motor is coupled to a second input of the combining gearbox, and the propulsor is coupled to an output of the combining gearbox, such that the propulsor is driveable in use by either or both of the internal combustion engine and the electric motor. Each of the internal combustion engine and the electric motor is coupled to its respective input by a respective clutch.

Abstract: In accordance with at least one aspect of this disclosure, there is provided a fuel system for a gas turbine engine of an aircraft, including a main inlet feed conduit fluidly connected to a primary manifold feed conduit and a secondary manifold feed conduit. A primary manifold fluidly connects the primary manifold feed conduit to a plurality of primary fuel injectors, and a secondary manifold fluidly connects the secondary manifold feed conduit to a plurality of secondary fuel injectors.

Abstract: A method for controlling a fuel metering device with a movable metering element, comprising at least two iterations of the following steps: a detection (E1) of a possible change in the operating state among two position sensors of the metering element, if no change in the operating state is detected, a determination (E2_1) of the position of the metering element from an average of the measurements of the sensors or otherwise a determination (E2_2) from the non-defective sensor, a determination (E4) of a fuel flow rate setpoint, a conversion (E5) of the flow rate setpoint, a determination (E6) of a command of displacement of the metering element, a control (E7) of the position of the metering element, and if a change in the operating state is detected, the calculation of an instantaneous fuel flow rate from the position of the metering element, and, during the second iteration of the method, the determination of the flow rate setpoint according to instantaneous flow rate to match the position setpoint t

Abstract: A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor is configured to drive a motor shaft. A transmission system includes at least one gear box. The transmission system is configured to receive rotational input power from each of the heat engine shaft and the motor shaft and to convert the rotation input power to output power. The motor shaft includes a disconnect mechanism to allow the heat engine to rotate with the electric motor stopped. The heat engine shaft includes a disconnect mechanism to allow the electric motor to rotate with the heat engine stopped.

Abstract: In a gas turbine engine of the type having a high-pressure (HP) spool and a low-pressure (LP) spool, methods of increasing surge margin and compression efficiency at a given thrust are provided. One method increases compression efficiency and comprises transferring mechanical power from the HP spool to the LP spool to reduce a corrected speed of a HP compressor therein and raise a working line of a LP compressor therein. Another method increases surge margin and comprises transferring mechanical power from the LP spool to the HP spool to increase a corrected speed of a HP compressor therein and lower a working line of a LP compressor therein.

Abstract: A fuel system includes a fuel metering unit having a fuel inlet and a fuel outlet defining a flow path therebetween. The fuel system includes a bleed valve in fluid communication with the flow path of the fuel metering unit. The fuel system includes a controller in communication with the fuel metering unit and the bleed valve to send data thereto and/or receive data therefrom. The bleed valve is configured and adapted to open or close depending on a command from the controller. The flow path is configured and adapted to be in selective fluid communication with a fuel system interstage through the bleed valve.

Abstract: A system includes a generator using a fluid mixture obtained via a generator inlet, a compressor having a compressor inlet that is connected to a generator outlet by a first set of conduits, a second set of conduits connected to the compressor outlet and the generator inlet, and a sensor in communication with the second set of conduits, where a portion of the fluid mixture includes gas from a hydrocarbon well, and where exhaust fluid of the generator is provided to the compressor. A process includes obtaining a target fluid property and a fluid measurement using the sensor and modifying a parameter of a fluid control device to modify a first flow rate of the flow of the exhaust fluid through the second set of conduits relative to a second flow rate of the flow of the gas provided by the hydrocarbon well through the first set of conduits.

Abstract: The present invention discloses a CO alarm for a battery type generator, comprising a MCU control unit U2, configured to analyze and process signals, which is in a deep sleep state when the generator is not running, and enters a sleep plus timing wake-up working state after the engine is running; a CO sensor detection unit U3 connected to the MCU control unit, configured to convert the CO concentration in the environment into a corresponding electrical signal and output to the MCU control unit U2 for processing; an alarm indication unit U4 connected to the MCU control unit, configured to give an alarm prompt for the CO concentration and an alarm failure prompt.

Abstract: A hybrid electric gas turbine engine system includes a first compressor and an auxiliary compressor. The first compressor is configured to output first compressed air. The auxiliary compressor is configured to operate in parallel with the first compressor to output second compressed air. A controller is configured to selectively activate the first compressor or the auxiliary compressor based on an operating condition of the hybrid electric gas turbine engine system.

Abstract: A method for operating a power plant having a gas turbine, a heat recovery steam generator, a steam turbine, an auxiliary heat source, and a control system, wherein the method includes controlling the power plant such that the heat recovery steam generator receives an input of heat from the gas turbine; determining the gas turbine is operating at its maximum capacity or at an upper end of its control range and the power plant is operating at less than a target value for a power plant capacity; determining a target pressure value immediately upstream of the steam turbine, wherein the target pressure value is derived from a primary pressure for the steam turbine and a steam turbine capacity for the steam turbine; based upon the target pressure value, controlling the heat store to release heat into the heat recovery steam generator to achieve the predefined power plant capacity.

Abstract: A system and method for adaptively controlling a cooldown cycle of an auxiliary power unit (APU) that is operating and rotating at a rotational speed includes reducing the rotational speed of the APU to a predetermined cooldown speed magnitude that ensures combustor inlet temperature has reached a predetermined temperature value, determining, based on one or more of operational parameters of the APU, when a lean blowout of the APU is either imminent or has occurred, and when a lean blowout is imminent or has occurred, varying one or more parameters associated with the shutdown/cooldown cycle.

Abstract: A fuel supply system for a turbomachine, comprising a fuel circuit comprising pressurizer at the output of the circuit, a pump arranged to send into the circuit a fuel flow rate which is an increasing function of the rotational speed of a shaft of the pump, and a control circuit arranged to control the device to comply with a flow rate setpoint at the output of the fuel circuit. The system further comprises a feedforward corrector circuit configured to calculate an increment of the flow rate setpoint as a function of the engine speed of the turbomachine and of a variation in the engine speed of the turbomachine, and to add this increment to the flow rate setpoint. A method of regulating the pump is also described.

Abstract: A gas turbine engine for an aircraft includes an engine core including a first, lower pressure, turbine, a first compressor, and a first core shaft connecting the first turbine to the first compressor; and a second, higher pressure, turbine, a second compressor, and a second core shaft connecting the second turbine to the second compressor, and a fan located upstream of the engine core and including a plurality of fan blades extending from a hub. A turbine to fan tip temperature change ratio of a low pressure turbine temperature change to a fan tip temperature rise is in the range from 1.46 to 2.0.

Abstract: A hybrid electric propulsion system includes a gas turbine engine having at least one compressor section and at least one turbine section operably coupled to a shaft. The hybrid electric propulsion system includes an electric motor configured to augment rotational power of the shaft of the gas turbine engine. A controller is operable to determine an estimate of hybrid electric propulsion system parameters based on a composite system model and sensor data, determine a model predictive control state and a prediction based on the hybrid electric propulsion system parameters and the composite system model, determine a model predictive control optimization for a plurality of hybrid electric system control effectors based on the model predictive control state and the prediction using a plurality of reduced-order partitions of the composite system model, and actuate the hybrid electric system control effectors based on the model predictive control optimization.

Abstract: Embodiments of system and methods for supplying fuel, enabling communications, and conveying electric power associated with operation of a hydraulic fracturing unit of a plurality of hydraulic fracturing units are disclosed and may include a fuel line connection assembly configured to be connected to the first hydraulic fracturing unit and to supply fuel from a fuel source to a gas turbine engine connected to the hydraulic fracturing unit. A system also may include a communications cable assembly configured to be connected to the hydraulic fracturing unit and to enable data communications between the hydraulic fracturing unit and a data center or another hydraulic fracturing unit. A system further may include a power cable assembly configured to be connected to the hydraulic fracturing unit and to convey electric power between the hydraulic fracturing unit and a remote electrical power source or the plurality of hydraulic fracturing units.

Abstract: A method for operating a gas turbine at a desired gas turbine production value. The method includes setting a desired gas turbine production value based on a schedule of a reference gas turbine shaft speed with respect to ambient temperature and an exhaust temperature; comparing values of a gas turbine shaft speed to the reference gas turbine shaft speed to determine whether a difference between the gas turbine shaft speed and the reference gas turbine shaft speed is within or outside of a predetermined range; and in response to the difference being outside of the predetermined range, initiating a change in gas turbine shaft speed to cause the gas turbine to operate approximately at the desired gas turbine production value.

Abstract: A system and method for controlling an aircraft turbine engine. The control system includes: a nominal-mode processing chain including a global corrector designed to control a speed of rotation of the turbine engine by delivering a position setpoint for a fuel metering device, and a local corrector designed to control a position of the fuel metering device by delivering a nominal-mode control current, a degraded-mode processing chain including a direct corrector designed to control the speed of rotation of the turbine engine by delivering a degraded-mode control current, and a mode management module designed to deliver, to the fuel metering device, the nominal-mode control current in the absence of failure of a position sensor measuring a position of the fuel metering device, and the degraded-mode control current in the case of failure of the position sensor.

Abstract: A method for stopping an engine of a rotorcraft in overspeed, the rotorcraft comprising at least one engine, the engine comprising a gas generator and a power assembly, the power assembly comprising at least one power turbine rotated by gases originating from the gas generator, the power assembly comprising at least one power shaft rotationally secured to the power turbine, the power assembly rotating about a longitudinal axis at a speed referred to as the “speed of rotation”. The method comprises steps consisting in measuring a current value of the speed of rotation, determining a time derivative of the current value of the speed of rotation, referred to as the “current derivative ( d ? ? N ? ? 2 ? ? i d ? t ) ” , and automatically stopping the engine when the current derivative ( d ? ? N ? ? 2 ? ? i d ? t ) changes sign.

Abstract: A turboshaft gas turbine engine comprises, in fluid flow series, a gas-generator compressor, a combustor, a gas-generator turbine, and a free power turbine. The expansion ratios of the turbines are dependent upon an outlet temperature of the combustor, and an expansion relationship between the turbines is defined as the ratio of expansion ratios of the turbines over a running range of non-dimensional power outputs of the gas turbine engine. A second derivative of the expansion relationship is from 0.6 to 1.0.

Abstract: A steam turbine plant is provided with: a boiler; a fuel valve; a low-temperature steam generation source; a steam turbine; a main steam line that guides steam generated in the boiler to the steam turbine; a main steam adjustment valve that is provided to the main steam line; a low-temperature steam line that guides low-temperature steam from the low-temperature generation source to a position closer to the steam turbine-side than the main steam adjustment valve in the main steam line; a low-temperature steam valve provided to the low-temperature steam line; and a control device. During a stopping process of the steam turbine plant, the control device sends a command to close the fuel valve, and then sends a command to open the low-temperature steam valve.

Abstract: A method for operating a power plant, having at least one gas turbine engine and at least one fuel gas compressor, includes supplying fuel gas through a utility supply line, compressing the fuel gas to a plant supply pressure in the operating fuel gas compressor, and supplying the compressed fuel gas to a plant supply line. The gas turbine engine is operated at a set power output according to a power demand signal. If a failure of an operating fuel gas compressor is detected, the power output of the gas turbine engine is reduced to an emergency power output (which is lower than the set power output), and the power output of the gas turbine engine is restricted to the emergency power output. The reduction of the power output is performed in one single step and is controlled by at least one feedforward control signal.