Abstract: A method for adjusting the operation of a turbomachine integrated with an exhaust gas recirculation (EGR) system is provided. The method may utilize the composition of an inlet fluid entering the turbomachine. The method may also utilize a variety of turbomachine operating data.

Abstract: A transition duct for a gas turbine includes a tubular body having a forward end and an aft end, the aft end surrounded by a frame component; an interior closure band within the aft end, covering interior top, bottom and side wall surfaces of the frame; and a plurality of cooling channels between the frame and the closure band, each having an inlet and an outlet at the forward and aft ends, respectively.

Abstract: A transition duct for a gas turbine includes a tubular body having a forward end and an aft end, the aft end surrounded by a frame component; an interior closure band within the aft end, covering interior top, bottom and side wall surfaces of the frame; and a plurality of cooling channels between the frame and the closure band, each having an inlet and an outlet at the forward and aft ends, respectively.

Abstract: A method for adjusting the operation of a turbomachine integrated with an exhaust gas recirculation (EGR) system is provided. The method may utilize the composition of an inlet fluid entering the turbomachine. The method may also utilize a variety of turbomachine operating data.

Abstract: A method of operating a combustor for a turbine includes flowing fuel through a symmetrical annular array of fuel nozzles to provide an asymmetrical fuel pattern across the combustor. The asymmetrical fuel flow is provided during a diffusion mode of operation prior to transition between the diffusion mode and a premixed mode of operation, during the transition and during the premixed mode of operation. Near full power, the fuel is supplied equally among the fuel nozzles operating in the premixed mode. The asymmetric fuel flow stabilizes the combustor and inhibits high amplitude combustion noise while achieving low emission operation in the premixed mode.

Abstract: A crossfire tube assembly joining adjacent combustors in a gas turbine engine includes an impingement sleeve within which a crossfire tube is centrally disposed. The impingement sleeve is pierced by an array of impingement cooling holes which form a plurality of small jets of cooling air impinging upon, and cooling, the crossfire tube. The space between the impingement sleeve and the crossfire tube forms a flow channel along which the spent impingement air flows in the axial direction before exiting into the interiors of the combustors. A flow dam at the center of the flow channel forces the impingement air to flow toward the ends. An outward flare in a portions of the crossfire tube extending beyond the extremity of the impingement sleeve directs air exiting the flow channel upon an annular flange which supports the crossflow assembly and thus improves cooling in this area.

Abstract: A transition duct in an advanced heavy duty gas turbine engine is cooled by impingement jets formed by apertures in a sleeve spaced a distance from the surface to be cooled. The sleeve is configured so as to duct spent impingement air towards the combustor, where it can be subsequently used for mixing with, and combustion of, the fuel, or for cooling of the combustor. The distance between the impingement sleeve and the transition duct surface is varied to control the velocity of air crossflow from spent impingement air in order to minimize the pressure loss due to crossflow. The cross-sectional areas of the apertures are varied to project impingement jets over the various distances and crossflow velocities. Generally, larger aperture areas are used with larger distances.

Abstract: A flameholder arrangement for a gas turbine combustor or the like includes a primary flameholder such as an elongated V-gutter extending across a main flow stream of gaseous components within the combustor. Vortices are shed by the trailing edges of the primary V-gutter flameholder and circulate in essentially two-dimension flow fields in planes normal to the elongated V-gutter to produce a downstream wake. In addition, a plurality of winglets are carried by the primary flameholder and are configured so as to shed vortices rotating about axes generally parallel to the main flow stream. More particularly, the winglets are carried by the outer surfaces of the V-gutter elongated walls, and lie in planes normal to the V-gutter walls and angled with respect to the flow stream. The resultant flow in the wake downstream of the V-gutter is three-dimensional for enhanced mixing of the gaseous components.

Abstract: A modular catalytic combustor for a gas turbine has a plurality of individual, non-metallic cylindrical catalyst beds, and a support structure for each of the individual catalyst beds. Each catalyst bed together with its support structure forms an individual catalyst module. Each support structure includes an outer cooled support cylinder, with the individual support cylinders of the various modules interconnected in spaced relationship with cooling air passageways between. There are means for supplying compressed air, such as from a gas turbine compressor, into the space surrounding the support cylinders. The outer cooled support cylinders are provided with apertures for entry of cooling and purge air from the surrounding space. Each of the catalyst beds has an integral, cylindrical, outer ceramic shell, and is positioned within a corresponding outer support cylinder. A sheet metal heat shield is interposed between and concentric with each of the outer support cylinders and the catalyst bed within.

Abstract: A stationary gas turbine combustor having a fuel nozzle and a combustion chamber receiving the fuel nozzle also contains a pressure wave interference element fixed within the interior of the combustor and disposed in the path of the variable pressure waves to modify the intensity of the pressure waves and the location of their nodes.

Abstract: A fuel nozzle for use with gas turbines includes a centrally disposed orifice for discharging fuel into a combustion chamber. A first annular passage surrounds the fuel orifice and discharges primary air adjacent the exit of the fuel orifice for effecting atomization of the fuel and mixture of the air with the fuel to provide a fuel/air spray having a predetermined spray angle. A second annular passage for supplying secondary air is provided surrounding the first passage. This second passage is formed to supply air in a manner which creates a relatively low pressure substantially at the base of the fuel/air spray. When operating at the low fuel flow rates corresponding to low loads, air is supplied only through the first air passage and a relatively narrow spray angle, with a substantial concentration of fuel, is achieved.