Combustor Nozzle/Premixer with Curved Sections

Abstract

An apparatus for premixing fuel and air prior to combustion in a gas turbine engine includes an annular fuel passage receiving fuel from a fuel source. The annular fuel passage includes a fuel plenum and has a wave shape with a peak section surrounded by trough sections. An annular air passage surrounds the annular fuel passage. The annular air passage receives air to be mixed with the fuel in the fuel passage for downstream combustion. A plurality of swirler vanes are disposed in the annular air passage adjacent the fuel plenum.

What is claimed is: 
     
         1 . An apparatus for premixing fuel and air prior to combustion in a gas turbine engine, the apparatus comprising:
 an annular fuel passage receiving fuel from a fuel source, the annular fuel passage having an upstream passage, a neck passage narrower than the upstream passage, and a fuel plenum section that curves from the neck passage to a wider passage;   an annular air passage surrounding the annular fuel passage, the annular air passage receiving air to be mixed with the fuel in the fuel passage for downstream combustion; and   a plurality of swirler vanes disposed in the annular air passage adjacent the fuel plenum section.   
     
     
         2 . An apparatus according to  claim 1 , wherein the fuel plenum section comprises fuel holes in the annular fuel passage, the fuel holes being disposed in the wider passage of the fuel plenum section. 
     
     
         3 . An apparatus according to  claim 2 , wherein the fuel plenum section narrows downstream of the wider passage such that the wider passage defines a peak section, and wherein the fuel holes are disposed in the peak section. 
     
     
         4 . An apparatus according to  claim 3 , wherein the swirler vanes are disposed surrounding annular fuel passage adjacent the peak section. 
     
     
         5 . An apparatus according to  claim 4 , wherein the fuel holes are disposed between the swirler vanes. 
     
     
         6 . An apparatus according to  claim 2 , comprising at least 40 fuel holes. 
     
     
         7 . An apparatus according to  claim 1 , wherein an exterior surface of the annular air passage is curved substantially corresponding to the fuel plenum section, the curved exterior surface reducing incoming circumferential non-uniformities of input air. 
     
     
         8 . An apparatus according to  claim 1 , wherein the fuel plenum section comprises fuel holes in the annular fuel passage, the fuel holes being disposed upstream of a trailing edge of the swirler vanes such that the fuel has sufficient axial velocity. 
     
     
         9 . An apparatus according to  claim 1 , wherein an entrance to the annular air passage is rounded. 
     
     
         10 . A combustor comprising:
 a casing; and   a plurality of nozzles disposed in the casing, wherein each of the nozzles includes:
 an annular fuel passage receiving fuel from a fuel source, the annular fuel passage having an upstream passage, a neck passage narrower than the upstream passage, and a fuel plenum section that curves from the neck passage to a wider passage, 
 an annular air passage surrounding the annular fuel passage, the annular air passage receiving air to be mixed with the fuel in the fuel passage for downstream combustion, and 
 a plurality of swirler vanes disposed in the annular air passage adjacent the fuel plenum section. 
   
     
     
         11 . A combustor according to  claim 10 , wherein the fuel plenum section comprises fuel holes in the annular fuel passage, the fuel holes being disposed in the wider passage of the fuel plenum section. 
     
     
         12 . A combustor according to  claim 11 , wherein the fuel plenum section narrows downstream of the wider passage such that the wider passage defines a peak section, and wherein the fuel holes are disposed in the peak section. 
     
     
         13 . A combustor according to  claim 12 , wherein the swirler vanes are disposed surrounding annular fuel passage adjacent the peak section. 
     
     
         14 . A combustor according to  claim 13 , wherein the fuel holes are disposed between the swirler vanes. 
     
     
         15 . A combustor according to  claim 10 , wherein an exterior surface of the annular air passage is curved substantially corresponding to the fuel plenum section, the exterior surface of the annular air passage and an interior surface of the casing defining a headend air passage, wherein the headend air passage is shaped to reduce incoming circumferential non-uniformities of input air. 
     
     
         16 . A combustor according to  claim 15 , wherein an entrance to the annular air passage is rounded. 
     
     
         17 . An apparatus for premixing fuel and air prior to combustion in a gas turbine engine, the apparatus comprising:
 an annular fuel passage receiving fuel from a fuel source, the annular fuel passage including a fuel plenum and having a wave shape with a peak section surrounded by trough sections;   an annular air passage surrounding the annular fuel passage, the annular air passage receiving air to be mixed with the fuel in the fuel passage for downstream combustion; and   a plurality of swirler vanes disposed in the annular air passage adjacent the fuel plenum.   
     
     
         18 . An apparatus according to  claim 17 , wherein the fuel plenum comprises fuel holes in the annular fuel passage. 
     
     
         19 . An apparatus according to  claim 19 , wherein the fuel holes are disposed in the peak section.