Abstract: Methods and systems are provided for premixing combustion fuel and air within gas turbines. In one embodiment, a combustor includes an upstream mixing panel configured to direct compressed air and combustion fuel through a premixing zone to form a fuel-air mixture. The combustor also includes a downstream mixing panel configured to mix additional combustion fuel with the fuel-air mixture to form a combustion mixture.

Abstract: A process for providing a fuel supplied to one or more combustors in a gas turbine engine system, comprising: reforming a fraction of the fuel in one or more fuel circuits of the gas turbine combustion system with a plasma reformer system to form at least one of hydrogen and higher order hydrocarbons to be supplied to the one or more combustors with a remaining fraction of the fuel; and controlling at least one of power and fuel flow to the plasma reformer system with an active feedback control system.

Abstract: A fiber-optic dynamic sensing module comprises a support member, a beam extending from the support member, and a pre-strained fiber Bragg grating sensor and a strain-free fiber Bragg grating sensor mounted on the beam. The pre-strained and strain-free fiber Bragg grating sensors each comprise a Bragg grating inscribed in a fiber. The Bragg grating of the pre-strained fiber Bragg grating sensor is packaged more tightly along a longitudinal direction of the beam than the Bragg grating of the strain-free fiber Bragg grating sensor.

Abstract: A premixer for a gas turbine combustor includes a first passage configured to inject a highly reactive fuel; and a second passage configured to inject an inert gas or a less reactive fuel or a mixture of both. The second passage is configured to form a layer of the inert gas or less reactive fuel or the mixture of both that blankets a layer of the highly reactive fuel. Another premixer includes a plurality of nozzles, each nozzle including a pair of concentric tubes, the pair of concentric tubes including a first tube configured to inject a highly reactive fuel and a second tube surrounding the first tube and configured to dispense an inert gas or a less reactive fuel or a mixture of both that blankets the highly reactive fuel.

Abstract: A method for monitoring and controlling a gas turbine, comprises predicting frequencies of combustion dynamics in a combustor using operating conditions of a gas turbine, receiving a signal from a sensor that is indicative of combustion dynamics in the combustor, and detecting a flashback if a frequency of the received signal does not correspond to the predicted frequencies.

Abstract: A method may detect a flashback condition in a fuel nozzle of a combustor. The method may include obtaining a current acoustic pressure signal from the combustor, analyzing the current acoustic pressure signal to determine current operating frequency information for the combustor, and indicating that the flashback condition exists based at least in part on the current operating frequency information.

Abstract: A turbomachine includes a compressor, a combustor operatively connected to the compressor, and an injection nozzle operatively connected to the combustor. The injection nozzle includes a main body having a first end section that extends to a second end section to define an inner flow path. The injection nozzle further includes an outlet arranged at the second end section of the main body, at least one passage that extends within the main body and is fluidly connected to the outlet, and at least one conduit extending between the inner flow path and the at least one passage.

Abstract: The present application provides a burner for use with a combustor of a gas turbine engine. The burner may include a center hub, a shroud, a pair of fuel vanes extending from the center hub to the shroud, and a vanelet extending from the center hub and/or the shroud and positioned between the pair of fuel vanes.

Abstract: Systems and methods for staged combustion are provided. One staged combustion system includes a first fuel source for supplying a first fuel having a first chemical composition, a first injector for injecting the first fuel, a second fuel source for supplying a second fuel having a second chemical composition such that a relative reactive concentration of one or more of hydrogen, carbon monoxide, a hydrocarbon, or a combination of two or more hydrocarbons, in the first chemical composition is different from that of the second chemical composition, and a second injector situated for injecting the second fuel downstream of the first injector.

Abstract: The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

Abstract: A nozzle for a gas turbine combustor includes a first radially outer tube defining a first passage having an inlet and an outlet, the inlet adapted to supply air to a reaction zone of the combustor. A center body is located within the first radially outer tube, the center body including a second radially intermediate tube for supplying fuel to the reaction zone and a third radially inner tube for supplying air to the reaction zone. The second intermediate tube has a first outlet end closed by a first end wall that is formed with a plurality of substantially parallel, axially-oriented air outlet passages for the additional air in the third radially inner tube, each air outlet passage having a respective plurality of associated fuel outlet passages in the first end wall for the fuel in the second radially intermediate tube.

Abstract: A hybrid fuel combustion nozzle for use with natural gas, syngas, or other types of fuels. The hybrid fuel combustion nozzle may include a natural gas system with a number of swozzle vanes and a syngas system with a number of co-annular fuel tubes.

Abstract: A pre-mixing apparatus for a turbine engine includes a main body having an inlet portion, an outlet portion and an exterior wall that collectively establish at least one fluid delivery plenum, and a plurality of fluid delivery tubes extending through at least a portion of the at least one fluid delivery plenum. Each of the plurality of fluid delivery tubes includes at least one fluid delivery opening fluidly connected to the at least one fluid delivery plenum. With this arrangement, a first fluid is selectively delivered to the at least one fluid delivery plenum, passed through the at least one fluid delivery opening and mixed with a second fluid flowing through the plurality of fluid delivery tubes prior to being combusted in a combustion chamber of a turbine engine.

Abstract: A method for assembling a premixing injector is provided. The method includes providing a centerbody including a center axis and a radially outer surface, and providing an inlet flow conditioner. The inlet flow conditioner includes a radially outer wall, a radially inner wall, and an end wall coupled substantially perpendicularly between the outer wall and the inner wall. Each of the outer wall and the end wall include a plurality of openings defined therein. The outer wall, the inner wall, and the end wall define a first passage therebetween. The method also includes coupling the inlet flow conditioner to the centerbody such that the inlet flow conditioner substantially circumscribes the centerbody, such that the inner wall is substantially parallel to the centerbody outer surface, and such that a second passage is defined between the centerbody outer surface and the inner wall.

Abstract: The present invention is directed to a lean direct injection (LDI) combustion system for a gas turbine using a shell and tube heat exchanger concept to construct a shell and tube lean direct injector (“LDI”) for the combustion system. One side of the LDI injector, either the shell side or the tube side, carries an oxidizer, such as air, to the combustor, while the other side of the LDI injector carries fuel to the combustor. Straight or angled holes drilled in an end plate of the combustor allow the fuel to enter the combustor and mix with air being injected into the combustor.

Abstract: Methods and systems for combustion dynamics reduction are provided. A combustion chamber may include a first premixer and a second premixer. Each premixer may include at least one fuel injector, at least one air inlet duct, and at least one vane pack for at least partially mixing the air from the air inlet duct or ducts and fuel from the fuel injector or injectors. Each vane pack may include a plurality of fuel orifices through which at least a portion of the fuel and at least a portion of the air may pass. The vane pack or packs of the first premixer may be positioned at a first axial position and the vane pack or packs of the second premixer may be positioned at a second axial position axially staggered with respect to the first axial position.

Abstract: A premixing device is provided. The premixing device includes a fuel inlet configured to introduce a fuel within the premixing device and an air inlet configured to introduce air within the premixing device. The premixing device also includes a plurality of swirler vanes configured to provide a swirl movement to the fuel and/or air to facilitate mixing of the fuel and air to form a gaseous pre-mix, wherein a shape of each of the plurality of swirler vanes is selected to control an axial velocity profile of the fuel and/or air within the premixing device.

Abstract: A method for operating a combustor is provided. The method includes supplying a predetermined amount of a first gaseous fuel to the combustor, wherein the first gaseous fuel has a first Modified Wobbe Index (MWI) and a first fuel reactivity, and supplying a predetermined amount of a second gaseous fuel to the combustor, wherein the second gaseous fuel has a second MWI that is lower than the first MWI and a second fuel reactivity that is higher than the first fuel reactivity. The method also includes mixing the first and second gaseous fuels together to form a blended gaseous fuel, and injecting the blended gaseous fuel into the combustor.

Abstract: A fiber gas sensor includes a fiber core with first and second refractive index periodic modulated grating structures having different amplitude modulation profiles positioned about the fiber core. A fiber cladding is positioned about the first and second refractive index periodic modulated grating structures. A sensing layer is positioned about the fiber cladding of one of the refractive index periodic modulated grating structures. The sensing layer includes a sensing material made of a Pd-based alloy, such as nano-PdOx, nano-Pd(x)Au(y)Ni(1-x-y) or nano-Pd/Au/WOx. The fiber gas sensor provides a measurement of localized, temperature-corrected gas concentration and composition from a combustion environment. A reflection-based or a transmission-based sensing system with an array of one or more fiber gas sensors is also described.

Abstract: A method to facilitate controlling flame-holding margins in a turbine engine is provided. The method includes coupling at least one turbine nozzle segment within the turbine engine, wherein the at least one turbine nozzle segment includes at least one vane extending between an inner band and an outer band. The method also includes positioning at least one fuel injection orifice in a surface of the at least one vane, channeling a fuel through the at least one fuel injection orifice into a compressed fluid flow to establish a jet penetration height, and defining an operating window by adjusting an operating parameter of the fuel to reduce the jet penetration height and to facilitate reducing the flame-holding margins.