Abstract: A premixer for a gas turbine combustor includes a centerbody, a swirler assembly, and a mixing duct. The swirler assembly includes an inner swirler with vanes that rotate air in a first direction and an outer swirler with vanes that rotate air in an opposite direction. The inner swirler vanes and the outer swirler vanes are separated by an annular splitter. The outer swirler vanes define an outlet plane, and the inner swirler vanes each have a trailing edge that is disposed at an acute angle relative to the outlet plane. In one aspect, the inner swirler is axially offset from the outer swirler. The mixing duct may also define fuel passages that deliver fuel to fuel outlets on the downstream end of the mixing duct. The premixer is designed for operation on gaseous fuel or liquid fuel.

Abstract: A premixer for a gas turbine combustor includes a centerbody, a swirler assembly, and a mixing duct. The swirler assembly includes an inner swirler with vanes that rotate air in a first direction and an outer swirler with vanes that rotate air in an opposite direction. The inner swirler vanes and the outer swirler vanes are separated by an annular splitter. The outer swirler vanes define an outlet plane, and the inner swirler vanes each have a trailing edge that is disposed at an acute angle relative to the outlet plane. In one aspect, the inner swirler is axially offset from the outer swirler. The mixing duct may also define fuel passages that deliver fuel to fuel outlets on the downstream end of the mixing duct. The premixer is designed for operation on gaseous fuel or liquid fuel.

Abstract: A gas turbine engine includes a combustor and a turbine. The combustor includes a pre-mixer having a body defining a plurality of fluid passages extending axially through the pre-mixer, wherein a cross-sectional projection of each of the plurality of fluid passages comprises one or more features that form a helical coil about an axis of the fluid passage along a length of the fluid passage, wherein the pre-mixer is configured to receive fuel from a fuel supply, receive air from an air supply, mix the fuel and air by flowing the fuel and air through the plurality of fluid passages, and imparting a swirling motion on the fuel and air, and supply the air-fuel mixture to a combustion zone. The combustor is configured to combust the air-fuel mixture, generating combustion fluids. The turbine is configured to receive the combustion fluids from the combustor and to use the combustion fluids to drive one or more stages of the turbine.

Abstract: The present disclosure relates to a fuel-air premixer for a turbine system. The fuel-air premixer includes a swirler and a centerbody. The swirler is configured to direct a flow of air through the premixer, and the centerbody is configured to inject fuel into the flow of air. Additionally, the centerbody includes an airfoil shape that reduces and/or substantially eliminates recirculation pockets to prevent autoignition and/or flame holding in a combustion chamber. Accordingly, the turbine system may produce fewer NOx emissions.

Abstract: A gas turbine engine includes a combustor and a turbine. The combustor includes a pre-mixer having a body defining a plurality of fluid passages extending axially through the pre-mixer, wherein a cross-sectional projection of each of the plurality of fluid passages comprises one or more features that form a helical coil about an axis of the fluid passage along a length of the fluid passage, wherein the pre-mixer is configured to receive fuel from a fuel supply, receive air from an air supply, mix the fuel and air by flowing the fuel and air through the plurality of fluid passages, and imparting a swirling motion on the fuel and air, and supply the air-fuel mixture to a combustion zone. The combustor is configured to combust the air-fuel mixture, generating combustion fluids. The turbine is configured to receive the combustion fluids from the combustor and to use the combustion fluids to drive one or more stages of the turbine.

Abstract: An axial fuel staging injector for a gas turbine includes a body. The body includes an upstream end and a downstream end. The body defines a primary compressed air flow path through which compressed air flows from a compressed air source to a transition duct of a gas turbine combustor. The body includes a plurality of outlets disposed on an interior surface thereof. Each outlet of the plurality of outlets includes a secondary fuel conduit in fluid communication with a secondary fuel source, and includes a first wall that defines a secondary fuel path. The secondary compressed air conduit is in fluid communication with a compressed air source, and includes a second wall disposed about the first wall in a substantially coannular arrangement, wherein the first wall and the second wall define a secondary compressed air flow path.

Abstract: An axial fuel staging injector for a gas turbine includes a body. The body includes an upstream end and a downstream end. The body defines a primary compressed air flow path through which compressed air flows from a compressed air source to a transition duct of a gas turbine combustor. The body includes a plurality of outlets disposed on an interior surface thereof. Each outlet of the plurality of outlets includes a secondary fuel conduit in fluid communication with a secondary fuel source, and includes a first wall that defines a secondary fuel path. The secondary compressed air conduit is in fluid communication with a compressed air source, and includes a second wall disposed about the first wall in a substantially coannular arrangement, wherein the first wall and the second wall define a secondary compressed air flow path.

Abstract: The present disclosure relates to a fuel-air premixer for a turbine system. The fuel-air premixer includes a swirler and a centerbody. The swirler is configured to direct a flow of air through the premixer, and the centerbody is configured to inject fuel into the flow of air. Additionally, the centerbody includes an airfoil shape that reduces and/or substantially eliminates recirculation pockets to prevent autoignition and/or flame holding in a combustion chamber. Accordingly, the turbine system may produce fewer NOx emissions.

Abstract: A premixing fuel nozzle assembly including a plurality of premixers for use in a combustor section of a turbine engine is provided. Each of the premixers of the pre-mixing fuel nozzle assembly including an annular outer ring, an annular inner hub, configured co-annular with the outer ring, a plurality of swirler vanes, a plurality of fuel injection orifices formed in each vane and an air-assist orifice formed about at least one of the plurality of fuel injection orifices. The plurality of swirler vanes extend radially outward from the annular inner hub toward the annular outer ring. The air-assist orifice generating a co-annular air-assist jacket about a fuel jet injected via the fuel injection orifice to provide additional momentum and thus mixing of the fuel jet with a downstream crossflow of fluid. A combustor section including the pre-mixing fuel nozzle assembly and method of assembling the pre-mixing fuel nozzle are additionally disclosed.