Abstract: A combustor assembly for a turbine engine includes a fuel nozzle located at an upstream end of the combustor assembly. The fuel nozzle includes both a fuel delivery passageway and a purge air passageway. The purge air passageway conveys a flow of purge air to cool the fuel nozzle. The combustor assembly also includes a combustion product return line that conveys a flow of combustion products from a position downstream of a combustion zone of the combustor back to the fuel nozzle. The combustion products are mixed with purge air, and the mixture is delivered into a combustion zone located just downstream of the fuel nozzle. The addition of the combustion products into the purge air reduces the amount of oxygen in mixed flow, which helps to reduce the generation of undesirable nitrogen oxide combustion byproducts. Also, the greater heat of the combustion products helps to increase the temperature of the mixture, which helps to maintain the stability of a pilot flame fed by the mixture.

Abstract: A system is provided for reducing NOx emission. The system includes a gas production source configured to produce a gas stream comprising NOx, and an oxidation catalyst positioned downstream of the gas production source. The oxidation catalyst is configured to oxidize NO gas molecules in the gas stream to yield higher order NxOy molecules. A removal system is positioned downstream of the oxidation catalyst and is configured to remove higher order NxOy molecules from the gas stream by solvent absorption or reaction. The system further includes a secondary NOx trimming system positioned downstream of the oxidation catalyst, wherein the secondary NOx trimming system is configured to inject a reactant into the gas stream, the reactant configured to react with NOx molecules present in the gas stream.

Abstract: A method for assembling a gas turbine combustor system is provided. The method includes providing a combustion liner including a center axis, an outer wall, a first end, and a second end. The outer wall is orientated substantially parallel to the center axis. The method also includes coupling a transition piece to the liner second end. The transition piece includes an outer wall. The method further includes coupling a plurality of lean-direct injectors along at least one of the liner outer wall and the transition piece outer wall such that the injectors are spaced axially apart along the wall.

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 low emission combustor includes a combustor housing defining a combustion chamber. A secondary nozzle is disposed along a centerline of the combustion chamber and configured to inject air or a first mixture of air and fuel on a downstream side of the combustion chamber. The secondary nozzle includes an air inlet configured to introduce a first fluid including air, a diluent, or combinations thereof into the secondary nozzle. At least one fuel plenum is configured to introduce a second fluid including a fuel, another diluent, or combinations thereof into the secondary nozzle and over a predetermined profile proximate to the fuel plenum. The predetermined profile is configured to facilitate attachment of the second fluid to the profile to form a fluid boundary layer and to entrain incoming first fluid through the fluid boundary layer to promote mixing of the first fluid and the second fluid and fuel to produce the first fluid.

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 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 and system for reducing the amount of nitrogen oxides (NOx) in a combustion gas waste stream by (1) analyzing the waste stream to determine the amount of NOx; (2) determining the stoichiometric amount of ammonia required to reduce the NOx concentration down to a required level or less; (3) determining the flow rate profile of NOx components across the combustion gas waste stream upstream of an ammonia injection grid; (4) selecting specific locations within the ammonia injection grid to activate ammonia valves; (5) injecting controlled amounts of ammonia vapor into the gas stream at grid locations corresponding to the location of NOx in the gas stream; and (6) treating the gas stream using a selective catalytic reduction unit to reduce the amount of NOx down to acceptable levels.

Abstract: A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages.

Abstract: Methods and apparatuses are provided for protecting a catalyst within a combustor. In one embodiment, a catalytic reactor includes a protective coating that may be chemically removed or mechanically removed while the catalytic reactor is disposed in a combustor.

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: Optical flame holding and flashback detection systems and methods are provided. Exemplary embodiments include a combustor including a combustor housing defining a combustion chamber having combustion zones, flame detectors disposed on the combustor housing and in optical communication with the combustion chamber, wherein each of the flame detectors is configured to detect an optical property related to one or more of the combustion zones.

Abstract: A system may detect a flame about a fuel nozzle of a gas turbine. The gas turbine may have a compressor and a combustor. The system may include a first pressure sensor, a second pressure sensor, and a transducer. The first pressure sensor may detect a first pressure upstream of the fuel nozzle. The second pressure sensor may detect a second pressure downstream of the fuel nozzle. The transducer may be operable to detect a pressure difference between the first pressure sensor and the second pressure sensor.

Abstract: The primary nozzles of a Dry Low NOx (DLN) combustor are configured to alternatively burn a first gas fuel or a second gas fuel, where the two gas fuels may have widely disparate energy content. Natural gas may be the first gas fuel and syngas may be the second gas fuel. An inner fuel circuit and an outer fuel circuit are provided to allow effective control of fuel/air mixing profiles, dynamics, primary pre-ignition and emission control by changing the fuel split between the two fuel circuits. The inner fuel circuit may be run in a diffusion combustion mode on many gas fuels.

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: 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: The low emission combustor includes a combustor housing defining a combustion chamber having a plurality of combustion zones. A liner sleeve is disposed in the combustion housing with a gap formed between the liner sleeve and the combustor housing. A secondary nozzle is disposed along a centerline of the combustion chamber and configured to inject a first fluid comprising air, at least one diluent, fuel, or combinations thereof to a downstream side of a first combustion zone among the plurality of combustion zones. A plurality of primary fuel nozzles is disposed proximate to an upstream side of the combustion chamber and located around the secondary nozzle and configured to inject a second fluid comprising air and fuel to an upstream side of the first combustion zone. The combustor also includes a plurality of tertiary coanda nozzles. Each tertiary coanda nozzle is coupled to a respective dilution hole.

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.