Combustor wth pre-mixing fuel nozzle assembly

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.

What is claimed as new and desired to be protected by Letters Patent of the United States is: 
     
         1 . A premixer of a fuel nozzle assembly, comprising:
 an annular outer ring;   an annular inner hub, configured co-annular with the outer ring;   a plurality of swirler vanes extending radially outward from the annular inner hub toward the annular outer ring;   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.   
     
     
         2 . The premixer as claimed in  claim 1 , wherein each of the plurality of swirler vanes includes:
 a fuel passage portion;   an airfoil portion;   one or more fuel passages extending through the fuel passage portion and the airfoil portion, the one or more fuel passages terminating at one or more of the plurality of fuel injection orifices formed through the airfoil portion; and   one or more air passage extending through the fuel passage portion and the airfoil portion, the one or more air passages terminating at one or more of the air-assist orifices formed through the airfoil portion and about the fuel injection orifice.   
     
     
         3 . The premixer as claimed in  claim 2 , wherein each of the plurality of fuel injection orifices are in fluid communication with the one or more fuel passages to generate a plurality of fuel jets and wherein the air-assist orifice is in fluid communication with the one or more air passages to form a co-annular air-assist jacket about at least one of the plurality of fuel jets. 
     
     
         4 . The premixer as claimed in  claim 3 , wherein the plurality of fuel jets and the co-annular air-assist jacket are mixed with an incoming cross-flow of air to generate a fuel-air mixture. 
     
     
         5 . The premixer as claimed in  claim 1 , wherein the plurality of swirler vanes are circumferentially spaced apart from each other about the inner hub, and define a plenum. 
     
     
         6 . The premixer as claimed in  claim 1 , wherein the plurality of fuel injection orifices are configured having varying areas to address pressure drop and jet penetration across each of the plurality of fuel injection orifices. 
     
     
         7 . The premixer as claimed in  claim 1 , wherein an area of the air-assist orifice formed about at least one of the plurality of fuel injection orifices and flow of air therethrough is optimized to provide improved jet penetration. 
     
     
         8 . A premixer of a fuel nozzle assembly comprising:
 an annular outer ring;   an annular inner hub, configured co-annular with the outer ring;   a plurality of swirler vanes extending radially outward from the annular inner hub toward the annular outer ring, each of the plurality of swirler vanes including a fuel passage portion and an airfoil portion;   a plurality of fuel injection orifices formed in each vane and through the airfoil portion;   an air-assist orifice formed co-annular with and about at least one of the plurality of fuel injection orifices and through the airfoil portion;   one or more fuel passages defined within each swirler vane and extending through the fuel passage portion and the airfoil portion, the one or more fuel passages terminating at one or more of the plurality of fuel injection orifices; and   one or more air passages extending through the fuel passage portion and the airfoil portion, the one or more air passages terminating at one or more of the air-assist orifices.   
     
     
         9 . The premixer as claimed in  claim 8 , wherein each of the plurality of fuel injection orifices are in fluid communication with the one or more fuel passages to generate a plurality of fuel jets and wherein the air-assist orifice is in fluid communication with the one or more air passages to form a co-annular air-assist jacket about at least one of the plurality of fuel jets. 
     
     
         10 . The premixer as claimed in  claim 8 , wherein the plurality of fuel jets and the co-annular air-assist jacket are mixed with an incoming cross-flow of air to generate a fuel-air mixture. 
     
     
         11 . A combustor section of a gas turbine engine, comprising:
 a combustion chamber;   a fuel nozzle assembly associated with the combustion chamber, the fuel nozzle assembly comprising a plurality of swirler vanes configured to swirl airflow, each of the plurality of swirler vanes comprising:
 a plurality of fuel injection orifices configured to inject a plurality of fuel jets into the airflow; and 
 an air-assist orifice configured about at least one of the plurality of fuel injection orifices and form an air-assist jacket about one or more of the fuel jets. 
   
     
     
         12 . The combustor section as claimed in  claim 11 , wherein the fuel nozzle assembly further comprises:
 an annular outer ring;   an annular inner hub, configured co-annular with the outer ring; and   the plurality of swirler vanes extending radially outward from the annular inner hub toward the annular outer ring.   
     
     
         13 . The combustor section as claimed in  claim 12 , wherein each of the plurality of swirler vanes includes:
 a fuel passage portion;   an airfoil portion; and   one or more fuel passages extending through the fuel passage portion and the airfoil portion, the one or more fuel passages terminating at one or more of the plurality of fuel injection orifices formed through the airfoil portion; and   one or more air passage extending through the fuel passage portion and the airfoil portion, the one or more air passages terminating at one or more of the air-assist orifices formed through the airfoil portion and about the fuel injection orifice.   
     
     
         14 . The combustor section as claimed in  claim 13 , wherein each of the plurality of fuel injection orifices are in fluid communication with the one or more fuel passages to generate a plurality of fuel jets and wherein the air-assist orifice is in fluid communication with the one or more air passages to form a co-annular air-assist jacket about at least one of the plurality of fuel jets. 
     
     
         15 . The combustor section as claimed in  claim 14 , wherein the plurality of fuel jets and the co-annular air-assist jacket are mixed with an incoming cross-flow of air to generate a fuel-air mixture. 
     
     
         16 . The combustor section as claimed in  claim 11 , wherein the plurality of swirler vanes are circumferentially spaced apart from each other about the inner hub, and define a plenum. 
     
     
         17 . The combustor section as claimed in  claim 12 , further comprising:
 an end cover that encloses the combustor;   a fuel manifold formed in the end cover; and   a plurality of connecting passages in fluid communication with the fuel manifold and the fuel nozzle assembly, the plurality of connecting passages configured to provide fuel to the plurality of swirler vanes.   
     
     
         18 . A method of assembly a fuel nozzle assembly, comprising:
 providing an outer ring;   positioning an inner hub coaxially within the outer ring such that a plenum is formed therebetween;   coupling a swirler between the outer ring and the inner hub, the swirler including a plurality of swirler vanes configured to rotate fluid flowing therethrough in a downstream direction, each of the plurality of swirler vanes comprising a fuel passage portion and an airfoil portion;   defining a plurality of fuel injection orifices in the airfoil portion of one or more of the plurality of swirler vanes, the plurality of fuel injection orifices configured to inject a plurality of fuel jets into the plenum; and   defining an air-assist orifice about at least one of the plurality of fuel injection orifices to form an air-assist jacket about one or more of the fuel jets, the air-assist orifice configured to provide increased momentum to the fuel jet during injection into the plenum.   
     
     
         19 . The method as claimed in  claim 18 , further comprising:
 defining one or more fuel passages extending through the fuel passage portion and the airfoil portion, the one or more fuel passages terminating at one or more of the plurality of fuel injection orifices formed through the airfoil portion; and   defining one or more air passage extending through the fuel passage portion and the airfoil portion, the one or more air passages terminating at one or more of the air-assist orifices formed through the airfoil portion and about the fuel injection orifice.   
     
     
         20 . The method as claimed in  claim 19 , wherein each of the plurality of fuel injection orifices are in fluid communication with the one or more fuel passages to generate the plurality of fuel jets and wherein the air-assist orifice is in fluid communication with the one or more air passages to form the co-annular air-assist jacket about at least one of the plurality of fuel jets.