Abstract: A fuel nozzle for use in a gas turbine includes a pre-mix flow passage for directing a flow segment of a flow of a working fluid through the fuel nozzle. A first swirler vane and a second swirler vane extend within the pre-mix flow passage. The first swirler vane provides a first wake region within the flow segment. The second swirler vane provides a second wake region within the flow segment. A fuel injection peg is disposed downstream from the first swirler vane and the second swirler vane. The fuel injection peg is positioned within the flow segment between the first wake region and the second wake region.

Abstract: A method of operating a combustor having a central nozzle and a plurality of outer nozzles surrounding the central nozzle is provided. The method includes providing a liquid fuel to only the plurality of outer nozzles at a specified total energy input. The method includes decreasing the liquid fuel to the plurality of outer nozzles while simultaneously increasing a gas fuel to the central nozzle and the plurality of outer nozzles to substantially maintain the specified total energy input. The method includes supplying a fuel-air ratio of the gas fuel to the central nozzle that exceeds a threshold value such that a central nozzle flame is anchored. An air-fuel ratio of the gas fuel to the plurality of outer nozzles is less than the threshold value such that a plurality of outer nozzle flames are lifted until a purge flow is supplied to the outer nozzles.

Abstract: A gas turbine engine having a combustor that includes: an inner radial wall defining a first interior chamber and a second interior chamber, wherein the first interior chamber extends axially from an end cover to a primary fuel injector, and the second interior chamber extends axially from the primary fuel injector to the turbine; an outer radial wall formed about the inner radial wall so that a flow annulus is formed therebetween; upstream fuel nozzles jutting into the flow annulus from the outer radial wall. The upstream fuel nozzles may include non-uniform circumferential spacing about the inner radial wall.

Abstract: A fuel nozzle for use in a gas turbine includes a pre-mix flow passage for directing a flow segment of a flow of a working fluid through the fuel nozzle. A first swirler vane and a second swirler vane extend within the pre-mix flow passage. The first swirler vane provides a first wake region within the flow segment. The second swirler vane provides a second wake region within the flow segment. A fuel injection peg is disposed downstream from the first swirler vane and the second swirler vane. The fuel injection peg is positioned within the flow segment between the first wake region and the second wake region.

Abstract: A gas turbine includes a compressor section, a combustion section downstream from the compressor section, a turbine section downstream from the combustion section, and a controller. The controller controls the operation of the gas turbine at a reduced load, and is capable of querying a database including multiple sets of operational parameters for the gas turbine correlated with at least one measured output response at each set of operational parameters. One of the sets of operational parameters provides a desired gas turbine load that meets a target level for the output response. Related methods are also disclosed.

Abstract: An end cover for a gas turbine combustor includes a main body configured to connect to a casing that at least partially surrounds a portion of the gas turbine. A fuel circuit extends within the main body of the end cover. An orifice extends through the main body. The orifice is in fluid communication with the fuel circuit. The end cover further includes a linear actuator. The linear actuator includes a flow control member that extends the fuel circuit and at least partially through the orifice.

Abstract: A method of operating a combustor having a central nozzle and a plurality of outer nozzles surrounding the central nozzle is provided. The method includes providing a liquid fuel to only the plurality of outer nozzles at a specified total energy input. The method includes decreasing the liquid fuel to the plurality of outer nozzles while simultaneously increasing a gas fuel to the central nozzle and the plurality of outer nozzles to substantially maintain the specified total energy input. The method includes supplying a fuel-air ratio of the gas fuel to the central nozzle that exceeds a threshold value such that a central nozzle flame is anchored. An air-fuel ratio of the gas fuel to the plurality of outer nozzles is less than the threshold value such that a plurality of outer nozzle flames are lifted until a purge flow is supplied to the outer nozzles.

Abstract: A nozzle for gas turbine includes a tubular nozzle body; and a plurality of hollow fuel injection pegs extending radially from the tubular nozzle body at a location between forward and aft ends of the tubular nozzle body; wherein each of the plurality of hollow fuel injection pegs has an external tear-drop cross-sectional shape, and a fuel passage in each of the hollow injection pegs has a substantially matching internal tear-drop cross-sectional shape.