General Electric Company

Catalytica, Inc.

Tanaka Kikinzoku K.k.

Kenneth W Beebe

Martin B Cutrone

Robert Joseph Iasillo

Stephen L Hung

L Berkly Davis

Ralph Albert Dalla Betta

Albert Myers

Sanjay M Correa

Stephen Lan-Sun Hung

Victor R Gardy

James C Schlatter

L Berkley Davis

Leslie Boyd Keeling

Gale V Slocum

Jeffery Alan Lovett

A device for conditioning the flow of hot gas in a catalytic combustor in preparation for entry into a catalytic reactor. The device is composed of at least one and most preferably two or more disks that are secured to a shroud so as to be disposed in a plane generally perpendicular to the hot gas flow direction. Each disk is composed of a plurality of small cells oriented so that flow channels therethrough are axially disposed. The cells linearize the gas flow and exert drag on the gas flow therethrough. This generates a static pressure gradient in the flow fields upstream and downstream of the honeycomb disk, which in turn causes flow adjustments so as to produce a more uniform axial flow field. This results in a more uniform fuel/air concentration distribution and velocity distribution at the catalytic reactor inlet.

Catalytic combustor flow conditioner and method for providing uniform gasvelocity distribution

A hybrid combustor, for providing stable high and low levels of operation while minimizing emissions of NOx, CO, and UHCs, includes a casing having a chamber, a catalytic combustor disposed in the chamber, and a non-premixed combustor disposed in the chamber. The hybrid combustor may comprise a fuel nozzle comprising a casing having a chamber, and a body supportable in the chamber to define a passageway between the body and the casing. The passageway has an inlet for receiving a stream of air and an outlet for discharging a stream of fuel and air, and the body includes a tapering downstream portion. Desirably, flow separation of the fuel and air mixture from the body (i.e., recirculation of the fuel and air mixture in the passageway and/or chamber) is inhibited whereby a generally uniform fuel and air mixture is provided.

Hybrid catalytic combustor

Lean premixed combustion of a hydrocarbon fuel and air is combined with lean direct injection of hydrocarbon fuel and carrier fluid such as air or inert gas or a mixture of air and inert gas into a combustor downstream of the premixed reaction zone in order to achieve extremely low levels of emissions of oxides of nitrogen at the high combustor exit temperatures required by advanced heavy duty industrial gas turbines. One or more premixing fuel nozzles are used to supply a lean mixture of hydrocarbon fuel and air to the main or primary reaction zone of a gas turbine combustor. This lean fuel/air mixture has an adiabatic flame temperature below the temperature that would result in substantial thermal NOx formation. After this low temperature reaction has been completed, additional fuel and carrier fluid are injected into the products of combustion downstream of the main reaction zone in order to raise the temperature of the mixture to the level required to operate an advanced, high efficiency, heavy duty industrial gas turbine at high load. Formation of nitrogen oxides in the region after this secondary fuel and carrier fluid injection is minimized by partial premixing of fuel and carrier fluid prior to ignition and by minimizing the residence time between the secondary fuel injection and the turbine first stage inlet.

Premixing dry low nox emissions combustor with lean direct injection of gas fule

A support structure for securing a catalyst structure comprising a multiplicity of longitudinally disposed channels for passage of a flowing gas mixture within a reactor, said support structure being comprised of a monolithic open celled or honeycomb-like structure formed by thin strips or ribs of high temperature resistant metal or ceramic which abuts against one end of the catalyst structure, and extends in a direction perpendicular to the longitudinal axis of the catalyst structure to essentially cover an end face (at either the inlet end or outlet end or both) of the catalyst structure with the support structure being secured on its periphery to the reactor wall. The strips or ribs making up the support structure are bonded together to form a unitary structure having cellular openings at least as large as the catalyst structure channel openings. The cellular openings in the support structure are also positioned to be in fluid communication with the channels of the catalyst structure thus affording essentially unaltered gas flow from the catalyst structure through the support structure.

Support structure for a catalyst in a combustion reaction chamber

Lean premixed combustion of a hydrocarbon fuel and air is combined with lean direct injection of hydrocarbon fuel and air into a combustor downstream of the premixed reaction zone in order to achieve extremely low levels of emissions of oxides of nitrogen at the high combustor exit temperatures required by advanced heavy duty industrial gas turbines. One or more premixing fuel nozzles are used to supply a lean mixture of hydrocarbon fuel and air to the main or primary reaction zone of a gas turbine combustor. This lean fuel/air mixture has an adiabatic flame temperature below the temperature that would result in substantial thermal NOx formation. After this low temperature reaction has been completed, additional fuel and air are injected into the products of combustion downstream of the main reaction zone in order to raise the temperature of the mixture to the level required to operate an advanced, high efficiency, heavy duty industrial gas turbine at high load. Formation of nitrogen oxides in the region after this secondary fuel and air injection is minimized by partial premixing of fuel and air prior to ignition and by minimizing the residence time between the secondary fuel injection and the turbine first stage inlet.

Premixing dry low NOx emissions combustor with lean direct injection of

A combustor for a gas turbine includes a diffusion flame combustion zone, a catalytic combustion zone and a post-catalytic combustion zone. At start-up or low-load levels, fuel and compressor discharge air are supplied to the diffusion flame combustion zone to provide combustion products for the turbine. At mid-range operating conditions, the products of combustion from the diffusion flame combustion zone are mixed with additional hydrocarbon fuel for combustion in the presence of a catalyst in the catalytic combustion zone. Because the fuel/air mixture in the catalytic reactor bed is lean, the combustion reaction temperature is too low to produce thermal NO.sub.x. Under high-load conditions, a lean direct injection of fuel/air is provided in a post-catalytic combustion zone where auto ignition occurs with the reactions going to completion in the transition between the combustor and turbine section. In the post-catalytic combustion zone, the combustion temperature is low and the residence time in the transition piece is short, hence minimizing thermal NO.sub.x.

Catalytic combustor with lean direct injection of gas fuel for low

A fuel trimming unit has been adapted to each combustion chamber in a multi-chamber combustor of an industrial gas turbine. The fuel trim unit matches the combustion air flow into each combustion chamber. This adjusts the fuel-air mixture to account for air flow variations into the individual combustion reaction zones of each combustion chamber. Because of the fuel trim unit, a uniform fuel-air mixture is provided to each combustion chamber in a gas turbine. The fuel trim unit is adjusted using sensor inputs of the fuel flow rate to each combustion chamber, the dynamic pressure in each combustion chamber, and the turbine exhaust temperature.

Fuel trim system for a multiple chamber gas turbine combustion system

A gas turbine combustion system includes a plurality of combustors within a pressure vessel, each combustor including a combustion liner defining a combustion chamber having a reaction zone and a dilution zone, the liner in the dilution zone provided with a plurality of circumferentially spaced dilution air feed holes. A flow shield surrounds each combustion liner in radially spaced relation thereto for feeding compressor discharge air to the combustion chamber. Air staging apparatus directly controls the amount of compressor discharge air fed into each combustion chamber dilution zone via the dilution air feed holes. The apparatus includes a plurality of pressure vessel extraction ports and associated conduits for introducing compressor discharge air into a first manifold common to the plurality of combustors; a dilution air control valve located between each extraction port and the first manifold; and a second, annular manifold surrounding the flow shield and including feed tubes connecting the second manifold to each of the dilution air feed holes in the combustion liner.

Combustor external air staging device

Fuel trim method for a multiple chamber gas turbine combustion system

Dual fuel/air injectors are provided, including a conventional central diffusion flame fuel nozzle 12. A fuel injector 14 for pre-mixing fuel and air for low emissions combustion and coaxial to the central nozzle includes a plenum 30 about the central injector having an air inlet 32, an annular pre-mix chamber 34, a fuel injection region 36 between the pre-mix chamber and air inlet 32 and an outlet 40 defined in part by swirler vanes 38. Radially projecting fuel spokes 46 extend into the plenum 30 and are supplied fuel from a manifold 44. Apertures 52 in the spokes supply fuel in a circumferential direction to the incoming air. The spokes in the plenum define throat areas T which, in the aggregate, define a minimum cross-sectional area of the plenum 30. Differential air flows through the throats provide inverse differential fuel distribution in the throats whereby a uniform fuel/air mixture strength distribution occurs at the throats. The fuel/air pre-mix thus maintains uniform hot gas temperature distribution in the combustor reaction zone, minimizing the formation of pollutants in the exhaust.

Dual fuel injector with premixing capability for low emissions combustion

During low-load operating conditions, preburner combustion products are supplied with a chemical reactant to reduce NO.sub.x. The preburner products of combustion are mixed with a hydrocarbon fuel in the presence of a combustion catalyst to ignite and initiate a catalytic combustion reaction. The preburner is then shut down. The fuel/air mixture supplied the catalytic reactor bed during the mid-load operating range of the turbine is sufficiently lean to produce a combustion reaction temperature too low to produce thermal NO.sub.x. Thus, at low-load conditions, preburner combustion occurs with NO.sub.x reduction by chemical reactant, while the catalytic combustion occurs at mid-range operating conditions at temperatures too low to produce NO.sub.x. For high-load operating conditions, the catalytic combustion occurs as previously described and additional lean fuel/air mixture is supplied the reaction zone whereby thermal NO.sub.x is likewise avoided.

Gas turbine catalytic combustor with preburner and low NO.sub.x emissions

A method and apparatus are provided for reducing NOx emissions in dual stage, dual mode gas turbine combustors. The gas turbine combustor includes first and second combustion chambers separated by a reduced diameter throat section. The throat section is formed by converging and diverging wall sections constructed of porous material. A liner is provided in surrounding relationship to the throat region to form a plenum by which predetermined amounts of air are metered into the plenum and permitted to pass through the porous throat wall sections.

Transpiration cooled throat section for low NOx combustor and related

A laminated oxidation resistant catalyst element includes a metal alloy substrate such as a steel foil coated with a noble metal such as platinum. A ceramic washcoat such as alumina is applied over the noble metal and a catalyst is applied with the washcoat or individually during a subsequent application step. The noble metal prevents oxygen from contacting the metal substrate thereby preventing its degradation by oxidation reactions. The catalyst element is particularly suited for use in a catalytic reactor bed of an industrial gas turbine.

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Galway, NY, United States of America

Kenneth W Beebe