Abstract: An effusion cooled transition duct for transferring hot gases from a combustor to a turbine is disclosed. The transition duct includes a panel assembly with a generally cylindrical inlet end and a generally rectangular exit end with an increased first and second radius of curvature, a generally cylindrical inlet flange, and a generally rectangular end frame. Cooling of the transition duct is accomplished by a plurality of holes angled towards the end frame of the transition duct and drilled at an acute angle relative to the outer wall of the transition duct. The combination of the increase in radii of curvature of the panel assembly with the effusion cooling holes reduces component stresses and increases component life. An alternate embodiment of the present invention is shown which discloses shaped angled holes for improving the film cooling effectiveness of effusion holes on a transition duct while reducing film blow off.

Abstract: A transition duct with a thermally free aft frame for use in a gas turbine engine is disclosed. The transition duct includes an aft frame that is thermally free through the use of a plurality of retention lugs, bushings, and bulkhead assemblies. The aft frame is allowed to adjust from thermal changes as a result of relative sizing between the bushings and retention lugs of the aft frame. An additional feature of this invention is the use of radially extending ribs along the sidewalls of the aft frame, to form an interlocking sealing means with adjacent transition ducts to reduce the amount compressor air leakage into the turbine inlet.

Abstract: Interaction between mating gas turbine combustor components due to vibrations and assembly tolerances can cause excessive wear and premature replacement. Typically, wear reduction features, such as hardened materials, are used to minimize the amount of wear or direct such wear to a specific component. The present invention discloses an improved wear reduction device for the interface between a gas turbine combustor transition duct end frame and the turbine inlet. The improved wear reduction device incorporates “L-shaped” wear strip inserts, constructed of a hardened material, and fixed along the sidewalls of the end frame to protect it from wear by the mating turbine inlet seal. The improved wear strip insert provides a cost savings by not requiring costly manufacturing tooling to form the wear strip inserts, unlike previous wear reduction techniques for the same component interface.

Abstract: An effusion cooled transition duct for transferring hot gases from a combustor to a turbine is disclosed. The transition duct includes a panel assembly with a generally cylindrical inlet end and a generally rectangular exit end with an increased first and second radius of curvature, a generally cylindrical inlet flange, and a generally rectangular end frame. Cooling of the transition duct is accomplished by a plurality of holes angled towards the end frame of the transition duct and drilled at an acute angle relative to the outer wall of the transition duct. The combination of the increase in radii of curvature of the panel assembly with the effusion cooling holes reduces component stresses and increases component life. An alternate embodiment of the present invention is shown which discloses shaped angled holes for improving the film cooling effectiveness of effusion holes on a transition duct while reducing film blow off.

Abstract: An effusion cooled transition duct for transferring hot gases from a combustor to a turbine is disclosed. The transition duct includes a panel assembly with a generally cylindrical inlet end and a generally rectangular exit end with an increased first and second radius of curvature, a generally cylindrical inlet sleeve, and a generally rectangular end frame. Cooling of the transition duct is accomplished by a plurality of holes angled towards the end frame of the transition duct and drilled at an acute angle relative to the outer wall of the transition duct. Effusion cooling geometry, including coverage area, hole size, and surface angle will be optimized in the transition duct to tailor the temperature levels and gradients in order to minimize thermally induced stresses. The combination of the increase in radii of curvature of the panel assembly with the effusion cooling holes reduces component stresses and increases component life.

Abstract: An improved gas turbine blade is disclosed that utilizes a blade tip shroud with tapered shroud pockets to remove excess weight from the shroud while not compromising shroud bending stresses. Excess shroud weight removed by the tapered pockets reduces overall blade pull while maintaining material necessary to increase shroud stiffness. The resulting rib created between the tapered pockets provides a surface, away from possible areas of stress concentration, for drilling radial cooling holes.

Abstract: A method for providing cooling air to the venturi and the combustion chamber in a low NOx emission combustor as used in a gas turbine engine that includes the steps of providing an annular air passage surrounding said combustion chamber and venturi where said cooling air under pressure enters the combustion chamber/venturi near the aft portion of the combustion chamber, passing the air along the combustion chamber, past the venturi where the air exits near the front portion of the convergent area of the venturi. The method prevents any channel/passage cooling air from being received into the combustion chamber, and at the same time, introduces the outlet of the cooling air, after the air has passed over the combustion chamber of the venturi and has been heated, back into the premix chamber thereby improving the efficiency of the combustor while reducing and lowering NOx emission in the combustion process.

Abstract: A wear reduction means for a fuel nozzle interface of an industrial gas turbine combustor is disclosed. The wear reduction means includes a replaceable insert welded into the engagement location of the fuel nozzle tip. The fuel nozzle tip is coated with a material harder than the replaceable insert, such that any wear due to mechanical contact of the mating components is directed to the replaceable insert.

Abstract: A method and apparatus for providing air cooling to the venturi and the combustion chamber in a low NOx emission combustor as used in a gas turbine engine that includes providing an annular air passage surrounding said combustion chamber and venturi where said cooling air enters the combustion chamber/venturi near the aft portion of the combustion chamber passing the air along the combustion chamber, past the venturi where the air exits near the front portion of the convergent area of the venturi. The structure prevents any channel/passage cooling air from being received into the combustion chamber at the same time introducing the outlet of the cooling air after it has passed over the combustion chamber of the venturi and been heated back into the premix chamber thereby improving the efficiency of the combustor while reducing and lowering NOx emission in the combustion process.

Abstract: A fuel nozzle system for use in a combustor utilized in a combustion turbine for reducing nitrogen oxides and other pollutants including an annular fuel distribution manifold separately mounted away from a diffusion nozzle, said annular manifold having a plurality of fuel emitting passages or holes disposed along the downstream side of the manifold, said manifold being mounted in a position away from the diffuser nozzle body to allow air to stream around the manifold on all sides allowing for a thorough mixture of fuel and air around the annular manifold for better premixing in the combustion chamber. In an alternate embodiment, the diffusion nozzle is replaced by a pilot flame nozzle that is supplied with both air and fuel through a premix air and fuel chamber to a pilot flame nozzle which is used to sustain combustion in the secondary chamber. The use of a pilot flame nozzle that has a fuel and air mixture is believed to reduced NOx emissions.

Abstract: A multiple directional axes structural support system for use as the aft end mount for a gas turbine transition duct to a turbine inlet is disclosed. The mounting system is configured to withstand high temperature gradients and mechanical loads associated with gas turbine environments while allowing multiple axes adjustment and interface capability between the transition duct and the turbine inlet casing. A spherical ball joint allows for rotation about multiple (three) axes to compensate for relative thermal growth, manufacturing tolerances, and assembly tolerances between mating surfaces. The ball joint is held in place by fitted spacers, bosses, and a through-bolt, that when torqued will dampen out unwanted vibrations in the multi-axis mounting system.

Abstract: An igniter assembly for a combustor of a gas turbine, the combustor being of a type including a case and a liner within said case, the assembly comprising an igniter including an elongate body having a first end, a second end, and a mounting feature intermediate said first and second ends, and the mounting feature includes a semi-hemispherical surface and an electrode extending through the body, and a base having an internal cavity with a first internal land, a second internal land opposite the first internal land, first seal A means in sealing contact with the first internal land, and biasing means, such as a spring, in contact with the second internal land and said mounting feature. The mounting feature is located within the cavity, the semi-hemispherical surface is proximate the first seal means, and the biasing means urges the semi-hemispherical surface into sealing contact with the first seal means to prevent the leakage of air therethrough.

Abstract: A combustion liner assembly for reducing nitric oxide (NOx) emissions is disclosed. This combustion liner utilizes an annular plenum outside the liner shell for the purpose of containing cooling air that has been heated and reintroducing it into the combustion process. The air plenum can be enlarged to increase the amount of cooling air contained within and still allow for installation of the liner assembly into the combustor by utilizing recesses that locally reduce the diameter of the air plenum to allow it to pass by liner mounting pegs within the combustor assembly.

Abstract: An improved dual-stage, dual-mode turbine combustor capable of reducing nitric oxide (NOx) emissions is disclosed. This can-annular combustor utilizes multiple, single wall sheet metal combustor liners, generally annular in shape, and each liner having multiple hole film cooling means, which includes at least one pattern of small, closely spaced film cooling holes angled sharply in the downstream direction and various circumferential angles for improved liner cooling and improved fuel/air mixing within the liner, resulting in lower NOx emissions.

Abstract: A gas turbine engine for generating electricity having low NOx emissions that includes a turbine system linearly and axially connected by a power shaft to a compressor section and having a combustion section mounted vertically relative to the turbine section and the compressor section. The combustion system includes a plurality of individual combustors mounted in a circular or annular array around the upper cap or dome of the combustion system, each of said combustors being a dual mode, two-stage, emitting low levels of NOx. Each combustor exhausts its combustion gases into a common central plenum chamber that is vertically oriented relative to the turbine engine centerline. The plenum provides the hot gases to the turbine blades through an annular chamber 360 degrees around the shaft. The gas turbine engine vertical combustion system provides for a highly efficient, low nitric oxide emissions while allowing for uniform mixing of the combusting gases powering the turbine system.

Abstract: A fuel nozzle system for use in a combustor utilized in a combustion turbine for reducing nitrogen oxides and other pollutants including an annular fuel distribution manifold separately mounted away from a diffusion nozzle, said annular manifold having a plurality of fuel emitting passages or holes disposed along the downstream side of the manifold, said manifold being mounted in a position away from the diffuser nozzle body to allow air to stream around the manifold on all sides allowing for a thorough mixture of fuel and air around the annular manifold for better premixing in the combustion chamber.