Abstract: A fuel nozzle for a gas turbine includes a nozzle body having a tip portion, the nozzle body including an inner tube defining an axially extending air passage; an intermediate tube concentrically arranged and radially spaced from the inner tube and defining a diffusion fuel passage therebetween; and an outer tube concentrically arranged and radially spaced from the intermediate tube and defining a premix fuel passage therebetween. The outer tube has a plurality of radially extending injectors in communication with the premix fuel passage. The premix fuel passage is further defined in part by an outer tube wall portion formed with at least one weakened region adapted to burn through in the event of a flashback, thereby causing a substantial portion of premix fuel to bypass the injectors and to exit the nozzle body at the at least one weakened region. A related method is also disclosed.

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 breech loaded fuel nozzle cartridge assembly is provided for use with a fuel nozzle capable of use with gaseous or distillate fuels. The cartridge assembly includes an elongated water delivery pipe having an interior through passageway extending from a rearward open end to a forward open end. A mounting coupling is fixed to the exterior of the pipe adjacent its rearward end for use in mounting the cartridge assembly within the rearward end of a fuel nozzle body. The forward end of the cartridge pipe is provided with an interior water swirler and an exterior distillate fuel swirler, while the forward end of the fuel nozzle body is provided with an air swirler so that at the fuel nozzle tip, an outer conical air spray, an intermediate distillate or gaseous fuel spray and an inner conical water spray combine to provide a homogenous mixture at the point of combustion.

Abstract: A breech loaded fuel nozzle cartridge assembly is provided for use with a fuel nozzle capable of use with gaseous or distillate fuels. The cartridge assembly includes an elongated water delivery pipe having an interior through passageway extending from a rearward open end to a forward open end. A mounting coupling is fixed to the exterior of the pipe adjacent its rearward end for use in mounting the cartridge assembly within the rearward end of a fuel nozzle body. The forward end of the cartridge pipe is provided with an interior water swirler and an exterior distillate fuel swirler, while the forward end of the fuel nozzle body is provided with an air swirler so that at the fuel nozzle tip, an outer conical air spray, an intermediate distillate or gaseous fuel spray and an inner conical water spray combine to provide a homogenous mixture at the point of combustion.