Abstract: A vane assembly for a gas turbine engine is disclosed having lower thermally induced stresses resulting in improved component durability. The stresses in the vane assembly airfoils are lowered by increasing the flexibility of the vane platform and reducing their resistance to thermal deflection. This is accomplished by placing an opening along the vane assembly rail that reduces the effective stiffness of the platform, thereby lowering the operating stresses in the airfoils of the vane assembly. A removable seal is then placed in the opening in order to prevent undesired leakages, while maintaining the benefit of the increased platform flexibility.

Abstract: A sealing device for use between a gas turbine combustor transition duct aft frame and a turbine inlet having improved durability, reduced wear on the mating turbine vane, and reduced manufacturing costs, is disclosed. The sealing device has a circumferential length, an axial width, and a radial height and contains a plurality of channels extending axially along the seal inner surface for passing a controlled amount of cooling air to a turbine inlet. The sealing device is formed of abradable honeycomb having a plurality of honeycomb cells with the honeycomb cells oriented to ensure maximum control against cooling air leakage while also providing maximum flexibility during assembly. The sealing device is captured between the transition duct aft frame, bulkhead, and turbine vane platform, thereby allowing easy replacement of the seal without requiring major disassembly of the transition duct aft frame section.

Abstract: A dual fuel premix nozzle and method of operation for use in a gas turbine combustor is disclosed. The dual fuel premix nozzle utilizes a fin assembly comprising a plurality of radially extending fins for injection of fuel and compressed air in order to provide a more uniform injection pattern. When in gas operation, the fuel and compressed air mixes upstream of the combustion chamber and flows into the combustion chamber as a homogeneous mixture. The premix fuel nozzle includes a plurality of coaxial passages, which provide gaseous fuel and compressed air to the fin assembly. When in liquid fuel operation, the gas circuits are purged with compressed air and liquid fuel and water pass through coaxial passages to the tip of the dual fuel premix fuel nozzle, where they inject liquid fuel and water into the secondary combustion chamber.

Abstract: A gas turbine transition duct having a reduced pressure loss is disclosed. The transition duct of the preferred embodiment comprises a panel assembly having a first panel fixed to a second panel and a mounting assembly for securing the transition duct to a turbine inlet. The first panel includes a means for augmenting the heat transfer from the first panel while the second panel includes a plurality of first cooling holes for directing cooling air through the second panel. Specific details are provided regarding the first cooling holes and multiple embodiments are disclosed for the heat transfer augmentation of the transition duct first panel.

Abstract: A fuel nozzle for use in a gas turbine combustor is provided having the capability of injecting multiple fuel types as well as steam for NOx reduction. Combustion dynamics within a combustor due to the mal-distribution of steam are controlled by the placement of a meterplate at the steam inlet, such that the meterplate reduces steam velocity and increases steam pressure drop. A higher pressure drop reduces the sensitivity of the combustion process to upstream steam supply variations. A method for providing uniform steam flow to a plurality of fuel nozzle assemblies about a gas turbine engine is also disclosed.

Abstract: A vane assembly for a gas turbine is described wherein the vane assembly comprises a first vane and a second vane connected together by a plurality of flanges, at least one fastener, and at least one spring plate. The fastener and hole diameters in the respective flanges are sized such that the first vane and second vane are essentially pinned together along their inner flanges and allowed to adjust due to thermal growth along their outer flanges, while maintaining a constant seal along both inner and outer platform edges. The thermal growth along the outer flanges is made possible by oversized flange holes relative to the diameter of the fastener.

Abstract: A gas turbine combustion liner is disclosed having an alternate interface region between it and a transition duct where the cooling effectiveness and heat transfer along the aft end of the combustion liner is improved, resulting in extended component life. The region of the combustion liner proximate its second end comprises a plurality of first feed holes, a plurality of spring seals that seal against a transition duct, a cooling ring having a plurality of second feed holes, that with the first feed holes pass a cooling fluid into an annulus formed between the cooling ring and combustion liner. The cooling fluid passes over a means for augmenting the heat transfer proximate the combustion liner second end, wherein the heat transfer augmentation preferably comprises a plurality of raised ridges that increases the surface area of the outer liner wall to turbulate the cooling fluid and maximize the cooling effectiveness.

Abstract: A fuel nozzle and gas turbine combustor capable of operating on multiple fuels with reduced carbon build-up to the fuel nozzle and adjacent combustor components is disclosed. The fuel nozzle incorporates a reconfigured gas fuel assembly and mixing tube to eliminate known areas of recirculation. Furthermore, the liquid fuel assembly includes reconfigured spray characteristics to further reduce droplet interaction with the mixing tube.

Abstract: A method of operating a gas turbine combustion system having reduced emissions and improved flame stability at multiple load conditions is disclosed. The improved combustion system accomplishes this through complete premixing, a plurality of fuel injector locations, combustor geometry, and precise three dimensional staging between fuel injectors. Axial, radial, and circumferential fuel staging is utilized including fuel injection proximate air swirlers. Furthermore, strong recirculation zones are established proximate the introduction of fuel and air premixture from different stages to the combustion zone. Fuel injection staging sequences are disclosed that create the conditions necessary to provide stable combustion and reduced emissions at multiple load conditions.

Abstract: The present invention seeks to provide a turbine blade with increased creep capability for both uncooled and cooled turbine blades while generally maintaining operating stress levels at an interface region between the turbine blade and a turbine disk. A turbine blade is disclosed having an attachment, a neck, a platform, and an airfoil. Extending radially outward from the attachment, through the neck, and terminating radially inward of the platform is a plurality of first cavities. The turbine blade in accordance with the preferred embodiment of the present invention is cast from a high density nickel base alloy with high temperature capability and improved creep capability. A plurality of first cavities are placed in the attachment and neck region to reduce excess weight of the turbine blade due to the higher density, greater creep capable alloy. Reducing the weight of the blade in this region provides increased creep capability in the turbine blade airfoil while maintaining operating stress levels.

Abstract: A gas turbine combustion system having reduced emissions and improved flame stability at multiple load conditions is disclosed. The improved combustion system accomplishes this through complete premixing, a plurality of fuel injector locations, combustor geometry, and precise three dimensional staging between fuel injectors. Axial, radial, and circumferential fuel staging is utilized including fuel injection proximate air swirlers. Furthermore, strong recirculation zones are established proximate the introduction of fuel and air premixture from different stages to the combustion zone. The combination of the strong recirculation zones, efficient premixing, and staged fuel flow thereby provide the opportunity to produce low emissions combustion at various load conditions.

Abstract: A turbine blade including an airfoil having a profile in accordance with Table 1 is disclosed. The turbine blade has a plurality of cooling passages extending radially outward through the airfoil. The aerodynamic profile of the airfoil has been reconfigured to reduce airfoil stress for a given operating temperature, thereby resulting in increased creep rupture life of the airfoil.

Abstract: A dual fuel premix nozzle and method of operation for use in a gas turbine combustor is disclosed. The dual fuel premix nozzle utilizes a fin assembly comprising a plurality of radially extending fins for injection of gas fuel and compressed air in order to provide a more uniform injection pattern and homogeneous mixture. The premix fuel nozzle includes a plurality of coaxial passages, which provide gaseous fuel and compressed air to the fin assembly. When in liquid fuel operation, the gas circuits are purged with compressed air and liquid fuel and water pass through coaxial passages to the tip of the dual fuel premix fuel nozzle, where they inject liquid fuel and water into the secondary combustion chamber. An alternate embodiment includes an additional gas fuel injection region located along a conically tapered portion of the premixed fuel nozzle, downstream of the fin assembly.

Abstract: A crossfire tube assembly is provided having an increased resistance to wear and oxidation. This increased resistance is provided by the application of coatings to the mating surfaces between the crossfire tube and crossfire tube clip. In the preferred embodiment, a physical vapor deposition (PVD) Titanium Aluminum Nitride coating is applied to the outer walls of the crossfire tubes which is used in combination with an air plasma spray (APS) Aluminum Bronze coating applied to the crossfire tube clip open end that mates with the crossfire tubes. The coating combination serves to protect the components from frictional wear and extend their life. In an alternate embodiment, the crossfire tubes also contain a plurality of air purge holes that provide a layer of cooling air along the crossfire tube inner wall.

Abstract: An attachment and sealing system for securing a combustor cap assembly to a combustion chamber, while providing effective cooling to the combustor cap assembly aft end, is disclosed. The combustor cap assembly is secured within a combustion chamber by a plurality of pins such that the aft end region of the combustor cap assembly is cooled by a fluid medium that is injected through a plurality of first holes in the combustion chamber wall. A generally annular seal, which encompasses the combustor cap assembly, has a plurality of raised ridges, which are in sealing contact with the combustion chamber wall. Multiple embodiments are disclosed regarding the length of the generally annular seal and position and orientation of the plurality of first cooling holes in the combustion chamber wall.

Abstract: A wear cover for use on a gas turbine transition duct support bracket is disclosed. The wear cover, which is manufactured from a single piece of sheet metal, does not require complex manufacturing processes or tools, thereby reducing component cost. The wear cover comprises first and second leg portions substantially parallel to each other and each generally perpendicular to a third leg portion. Each of the leg portions serve to protect a surface of a support bracket finger from excessive wear associated with frictional contact with mounting blocks of a transition duct. The wear cover is designed to slip onto a support bracket finger through a first opening and is fixed to the finger by a means such as welding.

Abstract: A premix fuel nozzle and method of operation for use in a gas turbine combustor is disclosed. The premix fuel nozzle utilizes a fin assembly comprising a plurality of radially extending fins for injection of fuel and compressed air in order to provide a more uniform injection pattern. The fuel and compressed air mixes upstream of the combustion chamber and flows into the combustion chamber as a homogeneous mixture. The premix fuel nozzle includes a plurality of coaxial passages, which provide fuel and compressed air to the fin assembly, as well as compressed air to cool the nozzle cap assembly. An alternate embodiment includes an additional fuel injection region located along a conically tapered portion of the premixed fuel nozzle, downstream of the fin assembly. A second alternate embodiment is disclosed which reconfigures the injector assembly and fuel injection locations to minimize flow blockage issues at the injector assembly.

Abstract: A pilot fuel nozzle configuration for use in a combustor is disclosed having a natural frequency outside the range of the operating frequencies of a gas turbine engine. Multiple embodiments are disclosed for the improved pilot fuel nozzle including configurations for newly manufactured nozzles, repair to existing pilot nozzles, as well as multiple natural frequency levels for the improved pilot fuel nozzle. The pilot fuel nozzle comprises an elongated housing, first and second flanges, and a nozzle tip, with the first flange fixed to the elongated housing at a first end and the nozzle tip fixed to the second end, opposite of the first end. The second flange is fixed along the elongated housing and is used for attaching the pilot fuel nozzle to a combustor. The present invention incorporates an increased wall thickness along at least a mid-span portion of the pilot nozzle to increase the stiffness and change the natural frequency.

Abstract: A method for providing a gas turbine engine and a combustor having a more uniform fluid flow is disclosed. For a combustor end cover, individual nozzle flow rates are determined and nozzles positioned on an end cover such that each nozzle injects substantially the same amount of fluid as an adjacent nozzle. As a result, gas temperature variations within the combustor are reduced and combustion dynamics lowered. For a gas turbine engine utilizing a plurality of combustors, individual end cover flow rates are determined and end covers positioned on each combustor relative to the supply inlet of the engine such that each end cover is supplied with a substantially similar flow rate. Other factors including pressure loss and fluid temperature changes are taken into consideration when determining nozzle and end cover positions.

Abstract: A method of operating a gas turbine combustor to achieve overall lower emissions of nitrous oxides by supplying a mixture of natural gas and hydrogen gas to the combustion chamber of the gas turbine in a manner that the localized concentration of hydrogen gas is greater than 0.1% by mass of the mass of the mixture, and less than 20.0% by mass of the mixture prior to combusting the mixture in the combustion chamber.