Abstract: A method and system for operating a gas turbine engine power system are provided. The system includes a gas turbine engine system that includes a gas turbine engine coupled to an electrical generator through a first shaft wherein the gas turbine engine includes a compressor, a combustion chamber, and a turbine drivingly coupled to the compressor and the electrical generator. The system also includes a variable speed electrical motor coupled to a load through a second shaft and a variable speed drive selectably couplable to the electrical generator during a starting sequence of the gas turbine engine system in a first configuration of the gas turbine engine power system and to the variable speed motor in a second configuration of the gas turbine engine power system.

Abstract: A bi-modal turbine assembly is provided for use in conjunction with a gas turbine engine. In one embodiment, the bi-modal turbine assembly includes a housing assembly having a flow passage therethrough, a turbine wheel rotatably mounted in the housing assembly and positioned so as to be driven by pressurized air flowing through the flow passage, an output shaft rotatably mounted in the housing assembly, and first and second gear trains disposed in the housing assembly. A switching device is also disposed in the housing assembly and configured to mechanically couple: (i) the first gear train between the turbine wheel and the output shaft in a first operational mode, and (ii) the second gear train between the turbine wheel and the output shaft in a second operational mode.

Abstract: Methods and apparatus for fast starting and loading a combined cycle power system are described. In one example embodiment, the method includes loading the gas turbine at up to it's maximum rate, and loading the steam turbine at its maximum rate with excess steam bypassed to the condenser while maintaining the temperature of steam supplied to the steam turbine at a substantially constant temperature from initial steam admission into the steam turbine until all steam generated by the heat recovery steam generator is being admitted to the steam turbine while the gas turbine operates at up to maximum load.

Abstract: A turbine installation includes a main group and an auxiliary group, wherein the main group has at least one first turbine and a generator connected for drive purposes to the first turbine. The auxiliary group includes at least one second turbine and is connectable to the main group via a coupling. The turbine installation furthermore includes a first braking device configured to apply a braking torque to the auxiliary group when the auxiliary group is decoupled from the main group.

Abstract: A method and apparatus are disclosed for a gas turbine power plant with a variable area turbine nozzle and an integrated motor/alternator device for starting the gas turbine and power extraction after starting.

Abstract: A gas turbine which can detect ignition in a combustor regardless of startup conditions of the gas turbine, such as the hot startup or the cold startup. An ignition detecting method for the gas turbine comprises the steps of calculating a difference between the exhaust temperature detected at a particular time before outputting of an ignition command for a combustor and the exhaust temperature detected after the outputting of the ignition command, and determining that the combustor is ignited, when the calculated difference is not less than a predetermined value. As an alternative, the method includes a step of determining that the combustor is ignited, when a change amount or rate of the exhaust temperature exceeds a predetermined value in a predetermined period from the outputting time of the ignition command.

Abstract: A dual channel ignition circuit (Channel A and a Channel B). In a start sequence in which a successful ignition event occurs, an exciter controller first energizes only a primary ignition channel (Channel A). Once the exciter controller recognizes a success light-off, the alternate channel (Channel B) will also then be excited as the gas turbine engine is accelerated to a self-sustaining speed. The exciter controller will then switch the primary alternative designation of the channels for the next start attempt. In a start sequence in which an unsuccessful ignition event occurs, the exciter controller sets a fail-to-start on the primary ignition channel on a failure to start A/B counter such that a failed ignition channel is diagnosed without dedicated electronic diagnostic circuits while still attempting to excite both circuits to enhance the dependability of a successful engine light-off.

Abstract: A system and method is provided for startup characterization in a turbine engine that provides the ability to accurately characterize engine startup. The startup characterization system and method uses engine temperature sensor data and engine speed sensor data to accurately characterize the startup of the turbine engine by determining when several key engine startup conditions are reached. By storing and analyzing engine sensor data taken during these key conditions of engine startup, the system and method is able to accurately characterize the performance of the engine during startup. This information can be used as part of a trending system to determine when faults in the start transient regime are occurring or likely to occur. Additionally, this information can be used in real time by control systems to better control the startup and operation of the turbine engine.

Abstract: A start system for a gas turbine engine delivers starter current according to a schedule selected according to measured rotational speed and oil temperature of the gas turbine engine.

Abstract: A compressor or fan is controlled to avoid stall, surge or flutter. The control system includes a look-up table from which is retrieved a margin-adjusted limiting value of a control parameter of the compressor, using inputs representing inlet guide vane angle (IGV), non-dimensional speed of the compressor (N/R?T), vehicle Mach number (Mn) and inlet geometry (IG). A variable stall, surge or flutter safety margin about a nominal limiting value of a control parameter is pre-established to reflect threats to the working, stall, flutter and surge lines, for example as a result of measurement inaccuracies, and from this the margin-adjusted limiting value is derived. An actual value of the control parameter is determined in real time, and the actual value is compared with the margin-adjusted limiting value. An output signal indicating stall, surge or flutter risk is generated if the actual value falls within the stall, surge or flutter safety margin.

Abstract: An aircraft gas turbine engine including a first hydraulic pump connected to a starter motor and a second hydraulic pump connected to the high-pressure compressor. The engine being arranged such that during starting the starter motor drives the first pump, to pump hydraulic fluid to operate the second pump as a motor to drive the high pressure compressor. During running the first and second pumps are connected to the aircraft hydraulic system.

Abstract: A fuel system (10) for a gas turbine engine (18) having a shaft (30) and requiring fuel to be supplied at a first rate for engine start up, the fuel system (10) including: a main fuel pump (14) for providing fuel to the gas turbine engine (18), the main fuel pump (14) having an output varying with shaft speed, the output being at a windmilling rate when the engine (18) is windmilling, the windmilling rate being less than the first rate; and an auxiliary fuel pump (40) for providing fuel to the gas turbine engine (18) and having an auxiliary output rate greater than or equal to the difference between the first rate and the windmilling rate. A method of operating such a fuel system (10) is also disclosed.

Abstract: A method for assembling a gas turbine engine including a core gas turbine engine, a low-pressure turbine, a starter, and a generator is provided. The method includes coupling a starter to the core gas turbine engine, and coupling a generator to the low-pressure turbine.

Abstract: With a generator-starter arrangement for a gas-turbine engine to supply the aircraft with electric power and to start the engine, the rotor (18) of the generator or starter, respectively, is formed by one of the rotors (4) of the high-pressure compressor (1) of the engine, which is provided with magnets (12) on individual blade tips, with the high-pressure compressor being surrounded in this area by a stator (17) of the generator or the starter, respectively. Such a generator-starter arrangement enables a high power requirement of the aircraft to be met, without causing stability or weight problems on the engine. In addition, the arrangement is easily accessible for maintenance and repair.

Abstract: Variable rate ignition method and system that take advantage of knowledge and analysis of environmental conditions and/or operational conditions. A variable ignition rate for igniting the engine permits an optimal use of the igniters and thereby prolongs their life as well as its associated maintenance schedule. Operating costs and durability are also enhanced. Furthermore, flexibility is enhanced since any changes to the method of determining the best spark rate can be made through update in the software of the engine controller instead of change in the hardware (e.g., the exciter).

Abstract: An aspect of the invention is directed towards a method and device for optimizing a light-up procedure of a gas turbine engine. An aspect of the method comprises repeating an engine start attempt with amended light-up parameter values or range of light-up parameter values, where the values are amended by a predefined scheme including recording the light-up parameter value or the range of light-up parameter values of each start attempt together with the light-up success rate achieved in the respective start attempts, and optimizing the light-up parameter value or range of parameter values by analyzing the recorded data after the start attempts have been finished. An aspect of the device is to provide a control unit that implements the inventive method.

Abstract: A system and method is provided for lightoff detection in a turbine engine that provides improved accuracy and consistency. The system and method use engine temperature and engine rotation speed sensor data to determine a first time interval during which the lightoff is estimated to have occurred. A peak gradient in the temperature sensor data within the first time interval and a peak gradient in the engine rotation sensor data within the first time interval are then determined. The temperature peak gradient time and the engine rotation peak gradient time are then used as boundaries to determine a narrowed time interval within the first time interval. The minimum gradient in the engine rotation sensor data in the narrowed time interval is determined, with the minimum gradient time in the engine rotation sensor data comprising an accurate estimate of lightoff time for the turbine engine.

Abstract: A method and an apparatus for starting a gas turbine engine under various conditions are used to distribute a varying total amount of electric power to at least one of a starter, a fuel heater and an oil heater while providing fuel.

Abstract: A gas turbine engine system includes an electric starter motor which utilizes a partially hollow or cupped shaped rotor. Space is provided inside the rotor to fit the required clutch, bearings, and drive shaft. A rotor shaft drives the input shaft through the clutch. The clutch is mounted within a clutch cavity formed within an annular housing portion of the housing. The annular housing portion is at least partially conical and preferably extends at least partially within a hollow rotor mounted to the rotor shaft. A short package is provided due to the telescoped architecture while retaining the maximum length for electromagnetics.

Abstract: A gas turbine includes a compressor, a combustor, a turbine, and a flow path diverting an excess portion of the compressed air produced by the compressor around the turbine. The flow path conducts the excess portion into a turbine exhaust gas flow producing a cooled exhaust gas. A method of operating the gas turbine includes opening an inlet guide vane of the compressor to allow the compressor to produce an increased volume of compressed air. The increased volume exceeds a volume of compressed air needed to support combustion. An excess portion of the compressed air is directed into the exhaust gas to produce a cooled exhaust. In a combined cycle power plant, the cooled exhaust from the gas turbine may be used to warm a steam turbine portion to a desired temperature while allowing operation of the gas turbine at a power level that produces exhaust gas at a temperature higher than the desired temperature.

Abstract: A main engine electric start system for gas turbine propelled aircraft that employs a low-power AC electrical power system to serve as an independent grid to control the functions of induction-type dynamoelectric machines coupled to the main propulsion engines and APU as a starter or generator.

Abstract: A starting system for starting the propulsion engines of gas turbine powered aircraft that combines power sources delivered by the APU so that essentially then entire power delivered by the APU for pneumatic, hydraulic and electric power is applied to corresponding starters on each propulsion engine during MES simultaneously.

Abstract: An auxiliary power unit for aircraft with a load compressor that delivers cabin air free of oil contamination by supporting a drive shaft for the load compressor with oil-free bearings and coupling the load compressor to a gearbox and power head for the auxiliary power unit through a synchronous magnetic torque coupling on an opposite side of the gearbox to which the power is mounted.

Abstract: A gas turbine starting method, comprising the steps of rotatively driving a turbine by a motor coupled to the turbine, while at the same time supplying a compressed air to a combustor by an air compressor operating in interlocking motion with the turbine, starting a fuel supply to the combustor when a revolution speed of the turbine has reached up to a predetermined value, and simultaneously starting an igniting operation on an air-fuel mixture in the combustor, wherein at least during the igniting operation to the air-fuel mixture in the combustor, a quantity of fuel supply per unit time to the combustor is increased while increasing the revolution speed of the turbine, to thereby ensuring the ignition of the air-fuel mixture under various conditions, and depressing the temperature rise of the gas turbine, which may otherwise occur immediately after the ignition.

Abstract: A method of engine starting in a gas turbine engine comprises rotating the engine to provide an air flow into a combustor of the engine and injecting fuel into the combustor at a varying rate until the engine is lighted-off. The varying rate of the fuel flow is a function of time and is represented by a curve having at least one high frequency with respect to a light-off time, representing instant changes of the rate for intersecting a light-off zone while reducing a quantity of fuel injected into the combustor. After the light-off occurrence fuel is continuously injected into the combustor to accelerate the engine to a self-sustaining operation condition. This method of the present invention is adapted to find light-off points under various temperature and altitude conditions, thereby advantageously providing a rapid light-off, particularly under cold weather conditions.

Abstract: A variable loading rate method of starting a plurality of gas turbines (GT1, GT2) used in a combined cycle power plant for generating electricity. A first gas turbine is started and allowed to operate at a minimum load condition. The turbine is maintained at this load level while a second gas turbine is started brought up to its minimum load condition. Start-up of a steam turbine (ST) to which the gas turbines are operationally coupled is initiated while both gas turbines are maintained at their minimum load conditions. The load on both gas turbines is then increased to a predetermined level, which is greater than their minimum load levels, once operating temperatures within the steam turbine reach predetermined levels. Subsequently, both gas turbines are loaded as function of the load on the a steam turbine at to which the gas turbines are coupled.

Abstract: A combined cycle power system is provided which can convert an open combined cycle gas turbine into a reduced or zero emissions power system. The system includes a compressor which compresses air and combusts the air with a hydrocarbon fuel. The products of combustion and the remaining portions of the air form the exhaust which is expanded through a turbine. The turbine drives the compressor and outputs power. The exhaust exits the turbine and then is routed through a heat recovery steam generator. A bottoming cycle portion of the system includes a gas generator which combusts a hydrocarbon fuel with oxygen. Water is also entered into the gas generator where it is heated and combined with the products of combustion, before entering a bottoming turbine. The water is then separated and routed back to the gas generator after preheating within the heat recovery steam generator.

Abstract: A system for starting an APU, including an air control valve assembly located in the air flow passageway extending between a source of pressurized air and a turbine power modulator. The system further includes a fuel control valve assembly located in the fuel flow passageway extending between a source of jet fuel and the turbine power modulator. Upon energizing the air control and fuel control valves, a mixture of compressed air and jet fuel entering the turbine power module is ignited, creating a flow steam of hot gases for driving a gas turbine to power the APU.

Abstract: A gas turbine starting method, comprising the steps of rotatively driving a turbine by a motor coupled to the turbine, while at the same time supplying a compressed air to a combustor by an air compressor operating in interlocking motion with the turbine, starting a fuel supply to the combustor when a revolution speed of the turbine has reached up to a predetermined value, and simultaneously starting an igniting operation on an air-fuel mixture in the combustor, wherein at least during the igniting operation to the air-fuel mixture in the combustor, a quantity of fuel supply per unit time to the combustor is increased while increasing the revolution speed of the turbine, to thereby ensuring the ignition of the air-fuel mixture under various conditions, and depressing the temperature rise of the gas turbine, which may otherwise occur immediately after the ignition.

Abstract: A combustor includes outer and inner liners joined together by a dome to define a combustor chamber. A row of air swirlers is mounted in the dome and includes corresponding main fuel injectors for producing corresponding fuel and air mixtures. Pilot fuel injectors fewer in number than the main injectors are mounted in the dome between corresponding ones of the swirlers. Staged fuel injection from the pilot and main injectors is used for starting the combustor during operation.

Abstract: A method of engine starting in a gas turbine engine comprises rotating the engine to provide an air flow into a combustor of the engine and injecting fuel into the combustor at a varying rate until the engine is lighted-off. The varying rate of the fuel flow is a function of time and is represented by a curve having at least one high frequency with respect to a light-off time, representing instant changes of the rate for intersecting a light-off zone while reducing a quantity of fuel injected into the combustor. After the light-off occurrence fuel is continuously injected into the combustor to accelerate the engine to a self-sustaining operation condition. This method of the present invention is adapted to find light-off points under various temperature and altitude conditions, thereby advantageously providing a rapid light-off, particularly under cold weather conditions.

Abstract: A method of engine starting in a gas turbine engine comprises rotating the engine to provide an air flow into a combustor of the engine and injecting fuel into the combustor at a varying rate until the engine is lighted-off. The varying rate of the fuel flow is a function of time and is represented by a curve having at least one high frequency with respect to a light-off time, representing instant changes of the rate for intersecting a light-off zone while reducing a quantity of fuel injected into the combustor. After the light-off occurrence fuel is continuously injected into the combustor to accelerate the engine to a self-sustaining operation condition. This method of the present invention is adapted to find light-off points under various temperature and altitude conditions, thereby advantageously providing a rapid light-off, particularly under cold weather conditions.

Abstract: A method for gas turbine light-off that utilizes a fixed or secondary fuel line that provides a substantially constant flow of fuel to the combustor primarily upon light-off.

Abstract: A method for ignition and start up of a gas turbine engine in which the fuel flow is supplied to the combustor at a substantially constant rate for ignition and the gas turbine engine is ramped up at a preset acceleration rate to a speed to provide a supply of combustion air to the combustor in order to achieve the correct fuel-to-air ratio for ignition.

Abstract: The invention relates to a method for starting a power plant (1), in particular a gas storage power plant, with the following steps:

Abstract: An emergency device for relighting a windmilling turbojet, the jet comprising a fan driven by a low-pressure turbine via a first shaft and a compressor driven by a high-pressure turbine via a second shaft disposed coaxially around the first shaft, a differential interconnecting said first and second shafts while compensating for their different speeds of rotation in normal operation or the turbojet, and a braking system connected to the differential so as to enable it to be slowed down or blocked when the turbojet shuts down, thereby enabling the first shaft to entrain the second shaft so that it reaches a speed that favors relighting of the turbojet.