Abstract: A transition duct assembly with a thermally free aft frame and mounting system for use in a gas turbine engine are disclosed. The aft frame is capable of adjusting to thermal gradients while the mounting system provides for at least transverse movement of the transition duct during engine assembly. The mounting system also provides a means for raising the natural frequency of the transition duct outside of the engine's dynamic excitation ranges.

Abstract: Embodiments for an apparatus and associated method for providing a cooling fluid to a gas turbine transition duct in order to lower the effective operating temperatures of the transition duct are disclosed. The transition duct has an inner liner and an impingement sleeve positioned radially outward with a passageway formed therebetween. The impingement sleeve has a plurality of openings where a portion of the openings each have a feed tube extending through the opening and into the passageway. The feed tubes are oriented at an angle relative to the impingement sleeve, such that an inlet to the feed tube is directed generally towards an oncoming flow of cooling fluid. The feed tubes direct a portion of the cooling fluid toward the inner liner and into the passageway for cooling of the transition duct.

Abstract: Embodiments for an apparatus and associated method for reducing the residence time in a gas turbine combustor are disclosed. The embodiments of the present invention comprise a fuel nozzle that extends to a downstream plane of an end cap for a combustion liner where the axial distance of the premixer is reduced, however the swirl for mixing the fuel and air, is increased. As a result, the mixing of the fuel and air is essentially unchanged, thereby allowing higher air pressures and operating temperatures within the premixer without inducing auto-ignition.

Abstract: A combustion liner having enhanced heat transfer over at least a portion of the liner is disclosed. The combustion liner comprises, amongst other features, an outer surface wherein at least a region of the outer surface is textured in a substantially uniform pattern such that the surface area exposed to a passing cooling medium is increased, thereby increasing the heat transfer through the combustion liner. Multiple embodiments of textured patterns are also disclosed.

Abstract: The present invention discloses an apparatus and method for reducing the carbon monoxide emissions emitted by a pilot injector of a gas turbine combustor. Multiple embodiments of a means for establishing a recirculation zone are disclosed whereby a portion of the fuel and air mixture from the pilot injector recirculates and a flame is held, thereby increasing the local reaction temperature at the desired location and lowering carbon monoxide emissions.

Abstract: An ignition system having improved reliability for a gas turbine combustor is disclosed. The ignition system comprises an outer housing having at least one fuel passage and an electrode extending therethrough forming a generally annular passage for cooling air to pass to a mixing chamber. Fuel and air mix in the mixing chamber to form a combustible mixture that is ignited by the electrode. The outer housing further comprises a plurality of air swirl holes to effectively cool the walls of the mixing chamber as well as to provide improved flame stability.

Abstract: The present invention provides a mixer for a gas turbine combustor comprising a plurality of generally annular walls interconnected by at least a plurality of first vanes. The vanes are oriented at angles, so as to create a shear layer between the two flows. A fuel is then injected so as to penetrate the shear layer for enhanced mixing. The mixture passes through an extended mixing passage to provide sufficient time and distance for improved mixedness prior to ignition. Multiple embodiments of the present invention are disclosed comprising a plurality of first vanes and a plurality of first and second vanes.

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 combustor having improved flashback margin is disclosed. Multiple embodiments of the present invention are disclosed including combustors having a single premix chamber as well as multiple premix chambers. Flashback margin is increased for the combustor by incorporating a means for introducing an inert gas, such as nitrogen, into the premix chamber(s) at the region proximate the boundary layer to purge the boundary layer of combustible mixture, thereby ensuring that no combustion reaction occurs in the boundary layer.

Abstract: A method of operating a gas turbine engine combustion system at lower load conditions while maintaining required emissions levels is disclosed. The present invention includes multiple embodiments of axial, radial, and circumferential fuel staging within a can-type combustor having alternate ignition techniques of spark ignition or torch ignition.

Abstract: A gas turbine combustor having a self-purging pilot fuel injection system and method of operation thereof is disclosed. The pilot fuel injection system comprises a radial inflow swirler, a generally axially extending centerbody, and at least one fuel injection source. In operation a fluid containing at least air passes along the centerbody outer surface clearing any remaining fuel from proximate the fuel injection source so as to prevent flame attachment proximate the fuel injection source.

Abstract: A combustion liner having enhanced heat transfer over at least a portion of the liner is disclosed. The combustion liner comprises, amongst other features, an outer surface wherein at least a region of the outer surface is textured in a substantially uniform pattern such that the surface area exposed to a passing cooling medium is increased, thereby increasing the heat transfer through the combustion liner. Multiple embodiments of textured patterns are also disclosed.

Abstract: The present invention provides a mixer for a gas turbine combustor comprising a plurality of generally annular walls interconnected by at least a plurality of first vanes. The vanes are oriented at angles, so as to create a shear layer between the two flows. A fuel is then injected so as to penetrate the shear layer for enhanced mixing. The mixture passes through an extended mixing passage to provide sufficient time and distance for improved mixedness prior to ignition. Multiple embodiments of the present invention are disclosed comprising a plurality of first vanes and a plurality of first and second vanes.

Abstract: The present invention discloses an apparatus and method for reducing the carbon monoxide emissions emitted by a pilot injector of a gas turbine combustor. Multiple embodiments of a means for establishing a recirculation zone are disclosed whereby a portion of the fuel and air mixture from the pilot injector recirculates and a flame is held, thereby increasing the local reaction temperature at the desired location and lowering carbon monoxide emissions.

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 supply system and method thereof that utilizes an off-gas in addition to the primary fuel to lower the emissions of a gas turbine combustion system is disclosed. The fuel supply system apparatus comprises a fuel gas supply conduit and an off-gas supply conduit in fluid communication with the fuel gas supply conduit such that the flow of an off-gas to the fuel gas supply conduit can be regulated as required by the operator to the desired fuel nozzle(s). The fuel gas supply preferably operates with natural gas and the off-gas supply preferably comprises the constituents hydrogen and methane.

Abstract: An ignition system having improved reliability for a gas turbine combustor is disclosed. The ignition system comprises an outer housing having at least one fuel passage and an electrode extending therethrough forming a generally annular passage for cooling air to pass to a mixing chamber. Fuel and air mix in the mixing chamber to form a combustible mixture that is ignited by the electrode. The outer housing further comprises a plurality of air swirl holes to effectively cool the walls of the mixing chamber as well as to provide improved flame stability.

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 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 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.