Pre-mixing based fuel nozzle for use in a combustion turbine engine

Abstract

A pre-mixing type of fuel nozzle ( 10 ) for use in a combustion turbine engine is provided. The nozzle includes an array of pre-mixing conduits ( 20 ) that extends between an inlet end ( 14 ) and an outlet end ( 16 ) of a body 12 of the nozzle. The nozzle may further include an array of air flow conduits ( 22 ) disposed radially inwardly relative to the array of pre-mixing conduits. The nozzle may include an inter-conduit passageway 24 arranged to aerodynamically reduce flow recirculation in the array of pre-mixing conduits. A fuel-directing structure ( 26 ) may include non-swirl elements ( 28 ) to direct fuel flow along a radial direction, each non-swirl element including at least one orifice ( 32 ) to inject the fuel flow directed along the radial direction into a respective pre-mixing conduit to pre-mix air and fuel.

21 . A fuel nozzle comprising:
 a body having an inlet end and an outlet end and defining a central axis that extends between the inlet end and the outlet end along an axial direction of the fuel nozzle;   an array of pre-mixing conduits extending between the inlet end and the outlet end of the body, the array of pre-mixing conduits circumferentially disposed about the central axis of the body, each pre-mixing conduit fluidly coupled to receive air at a respective inlet;   an array of air flow conduits disposed radially inwardly relative to the array of pre-mixing conduits;   means to aerodynamically reduce flow recirculation in the array of air/fuel pre-mixing conduits, wherein the means to aerodynamically reduce the flow recirculation in a respective pre-mixing conduit comprises an inter-conduit passageway arranged to provide fluid communication between the respective pre-mixing conduit and a corresponding air flow conduit; and   a fuel-directing structure in the body comprising a plurality of non-swirl elements, each non-swirl element including a radially-extending passageway to direct fuel flow along a radial direction, each non-swirl element including at least one orifice to inject the fuel flow directed along the radial direction into a respective pre-mixing conduit.   
     
     
         22 . The fuel nozzle of  claim 21 , wherein the array of pre-mixing conduits each comprises at least a respective pre-mixing conduit segment having a cross-sectional area that increases as the respective pre-mixing conduit segment extends from a location between the inlet end and the outlet end towards a respective outlet of the respective pre-mixing conduit. 
     
     
         23 . The fuel nozzle of  claim 22 , wherein the respective pre-mixing conduit segment includes at least one surface tilted radially inwardly relative to the central axis as the segment extends towards the respective outlet of the respective pre-mixing conduit. 
     
     
         24 . The fuel nozzle of  claim 21 , wherein the array of air flow conduits each comprises at least a respective air flow conduit segment having a cross-sectional area that decreases as the respective air flow conduit segment extends from a respective inlet towards a location between the inlet end and the outlet end. 
     
     
         25 . The fuel nozzle of  claim 21 , wherein the array of air flow conduits each comprises an outlet arranged radially inwardly relative to the central axis. 
     
     
         26 . The fuel nozzle of  claim 25 , wherein the fuel-directing structure further comprises a central passageway arranged to direct fuel along the axial direction. 
     
     
         27 . The fuel nozzle of  claim 26 , wherein the fuel-directing structure comprises a central outlet that in combination with the respective outlets of the array of air flow conduits forms a jet-assisted mixing stage. 
     
     
         28 . A combustor in a combustion turbine engine comprising the fuel nozzle of  claim 21 . 
     
     
         29 . A fuel nozzle comprising:
 a body having an inlet end and an outlet end and defining a central axis that extends between the inlet end and the outlet end along an axial direction of the fuel nozzle;   an array of pre-mixing conduits circumferentially disposed about the central axis of the body, each pre-mixing conduit fluidly coupled to receive air at a respective inlet, wherein the array of pre-mixing conduits each comprises at least a respective pre-mixing conduit segment having a cross-sectional area that increases as the respective pre-mixing conduit segment extends from a location between the inlet end and the outlet end towards a respective outlet of the respective pre-mixing conduit;   an array of air flow conduits disposed radially inwardly relative to the array of pre-mixing conduits, wherein the array of air flow conduits each comprises at least a respective air flow conduit segment having a cross-sectional area that decreases as the respective air flow conduit segment extends from a respective inlet towards a location between the inlet end and the outlet end; and   a fuel-directing structure in the body, the fuel-directing structure comprising a plurality of non-swirl elements each including a radially-extending passageway to direct fuel flow along a radial direction, each non-swirl element including at least one orifice to inject the fuel flow directed along the radial direction into a respective pre-mixing conduit.   
     
     
         30 . The fuel nozzle of  claim 29 , further comprising means to aerodynamically reduce flow recirculation in the array of pre-mixing conduits. 
     
     
         31 . The fuel nozzle of  claim 31 , wherein the means to aerodynamically reduce the flow recirculation in a respective pre-mixing conduit comprises an inter-conduit passageway arranged to provide fluid communication between the respective pre-mixing conduit and a corresponding air flow channel. 
     
     
         32 . The fuel nozzle of  claim 29 , wherein the respective pre-mixing conduit segment includes at least one surface tilted radially inwardly relative to the central axis, as the segment extends towards the respective outlet of the respective pre-mixing conduit. 
     
     
         33 . The fuel nozzle of  claim 29 , wherein the array of air flow conduits each comprises an outlet arranged radially inwardly relative to the central axis. 
     
     
         34 . The fuel nozzle of  claim 33 , wherein the fuel-directing structure further comprises a central passageway arranged to direct fuel along the axial direction. 
     
     
         35 . The fuel nozzle of  claim 34 , wherein the fuel-directing structure comprises a central outlet that in combination with the respective outlets of the array of air flow conduits forms a jet-assisted mixing stage. 
     
     
         36 . A combustor in a combustion turbine engine comprising the fuel nozzle of  claim 29 . 
     
     
         37 . A fuel nozzle comprising:
 a body having an inlet end and an outlet end and defining a central axis that extends between the inlet end and the outlet end along an axial direction of the fuel nozzle;   an array of pre-mixing conduits extending between the inlet end and the outlet end of the body, the array of pre-mixing conduits circumferentially disposed about the central axis of the body, each pre-mixing conduit fluidly coupled to receive air at a respective inlet, wherein the array of pre-mixing conduits each comprises at least a respective pre-mixing conduit segment having a cross-sectional area that increases as the respective pre-mixing conduit segment extends from a location between the inlet end and the outlet end towards a respective outlet of the respective pre-mixing conduit;   an array of air flow conduits disposed radially inwardly relative to the array of pre-mixing conduits;   an inter-conduit passageway arranged to provide fluid communication between a respective pre-mixing conduit and a corresponding air flow conduit; and   a fuel-directing structure in the body comprising a plurality of non-swirl elements, each non-swirl element including a radially-extending passageway to direct fuel flow along a radial direction, each non-swirl element including at least one orifice to inject the fuel flow directed along the radial direction into a respective pre-mixing conduit.