Burner for combustor with ammonia injection downstream of swozzle assembly and related method

Abstract

A burner includes an outer member and a center member inside the outer member and defining a fuel-air mixing passage therebetween. A swozzle assembly, which is positioned in the fuel-air mixing passage, includes a plurality of turning vanes configured to impart a swirl to an air flow flowing through the mixing passage. An ammonia injector system is downstream of the swozzle assembly to form an ammonia-air mixture for combustion in a combustion reaction zone in a combustion liner of the combustor. The ammonia injector system includes a first plurality of ammonia injectors configured to inject a first ammonia flow into the air flow and, optionally, a second plurality of ammonia injectors configured to inject a second ammonia flow into the air flow. Each ammonia injector has an injection axis aimed upstream from a radial position toward the air flow flowing through the mixing passage downstream of the swozzle assembly.

What is claimed is: 
     
         1 . A burner for a combustor of a gas turbine system, the burner comprising:
 an outer member;   a center member inside the outer member and defining a fuel-air mixing passage therebetween;   a swozzle assembly positioned in the fuel-air mixing passage, the swozzle assembly including a plurality of turning vanes configured to impart a swirl to an air flow flowing through the fuel-air mixing passage; and   an ammonia injector system downstream of the swozzle assembly, the ammonia injector system configured to form an ammonia-air mixture for combustion in a combustion reaction zone in a combustion liner of the combustor, the ammonia injector system including:
 a first plurality of ammonia injectors configured to inject a first ammonia flow into the air flow, 
 wherein each of the first plurality of ammonia injectors has an injection axis aimed upstream from a radial position toward the air flow flowing through the fuel-air mixing passage downstream of the swozzle assembly. 
   
     
     
         2 . The burner of  claim 1 , wherein the ammonia injector system includes a first ammonia supply line conveying the first ammonia flow to the first plurality of ammonia injectors; a second plurality of ammonia injectors configured to inject a second ammonia flow into the air flow; and a second ammonia supply line conveying the second ammonia flow to the second plurality of ammonia injectors; wherein each of the second plurality of injectors has an injection axis aimed upstream from the radial position toward the air flow. 
     
     
         3 . The burner of  claim 2 , further comprising a controller configured to selectively control ammonia flow to one or both of the first plurality of ammonia injectors and the second plurality of ammonia injectors depending on a combustor load, wherein the controller is configured to selectively control flow to one or both of the first ammonia supply line and the second ammonia supply line depending on the combustor load. 
     
     
         4 . The burner of  claim 2 , wherein the second plurality of ammonia injectors is axially downstream from the first plurality of ammonia injectors. 
     
     
         5 . The burner of  claim 4 , wherein the ammonia injector system includes:
 a first body axially downstream of the swozzle assembly and having a first ring manifold defined therein in fluid communication with the first ammonia supply line and the first plurality of ammonia injectors; and   a second body axially downstream of the first body, the second body having a second ring manifold defined therein in fluid communication with the second ammonia supply line and the second plurality of ammonia injectors.   
     
     
         6 . The burner of  claim 2 , wherein the ammonia injector system includes a single body having a first ring manifold defined therein in fluid communication with the first ammonia supply line and the first plurality of ammonia injectors, and a second ring manifold defined therein adjacent the first ring manifold and in fluid communication with the second ammonia supply line and the second plurality of ammonia injectors. 
     
     
         7 . The burner of  claim 1 , wherein each of the turning vanes includes an internal fuel flow passage in fluid communication with at least one fuel injector, and further comprising a fuel supply introducing a fuel other than ammonia into the internal fuel flow passage for injection into the air flow, wherein a fuel-air mixture generated by the swozzle assembly is directed into the combustion reaction zone in the combustion liner of the combustor. 
     
     
         8 . The burner of  claim 1 , further comprising a central fuel supply line defined within the center member, and a central fuel injector at a downstream end of the central fuel supply line, the central fuel injector configured to mix a fuel other than ammonia with another air flow to generate a fuel-air mixture for combusting in the combustion reaction zone in the combustion liner of the combustor. 
     
     
         9 . A combustor for a gas turbine system, the combustor comprising:
 a combustor body having a combustion liner;   a head end assembly having a cap assembly; and   a plurality of burners positioned in the cap assembly and directed into the combustion liner, at least one burner of the plurality of burners including:
 an outer member; 
 a center member inside the outer member and defining a fuel-air mixing passage therebetween; 
 a swozzle assembly positioned in the fuel-air mixing passage, the swozzle assembly including a plurality of turning vanes configured to impart a swirl to an air flow flowing through the fuel-air mixing passage; and 
 an ammonia injector system downstream of the swozzle assembly, the ammonia injector system configured to form an ammonia-air mixture for combustion in a combustion reaction zone in the combustion liner, the ammonia injector system including:
 a first plurality of ammonia injectors configured to inject a first ammonia flow into the air flow; and 
 a controller configured to selectively control ammonia flow to the first plurality of ammonia injectors depending on a combustor load, 
 wherein each of the first plurality of ammonia injectors has an injection axis aimed upstream from a radial position toward the air flow flowing through the fuel-air mixing passage downstream of the swozzle assembly. 
 
   
     
     
         10 . The combustor of  claim 9 , wherein the ammonia injector system includes a first ammonia supply line conveying the first ammonia flow to the first plurality of ammonia injectors; a second plurality of ammonia injectors configured to inject a second ammonia flow into the air flow; and a second ammonia supply line conveying the second ammonia flow to the second plurality of ammonia injectors, wherein the controller is configured to selectively control flow to one or both of the first ammonia supply line and the second ammonia supply line depending on the combustor load. 
     
     
         11 . The combustor of  claim 10 , wherein the second plurality of ammonia injectors is axially downstream from the first plurality of ammonia injectors. 
     
     
         12 . The combustor of  claim 11 , wherein the ammonia injector system includes:
 a first body axially downstream of the swozzle assembly and having a first ring manifold defined therein in fluid communication with the first ammonia supply line and the first plurality of ammonia injectors; and   a second body axially downstream of the first body, the second body having a second ring manifold defined therein in fluid communication with the second ammonia supply line and the second plurality of ammonia injectors.   
     
     
         13 . The combustor of  claim 10 , wherein the ammonia injector system includes a single body having a first ring manifold defined therein in fluid communication with the first ammonia supply line and the first plurality of ammonia injectors, and a second ring manifold defined therein adjacent the first ring manifold and in fluid communication with the second ammonia supply line and the second plurality of ammonia injectors. 
     
     
         14 . The combustor of  claim 9 , wherein each of the turning vanes includes an internal fuel flow passage in fluid communication with at least one fuel injector, and further comprising a fuel supply introducing a fuel other than ammonia into the internal fuel flow passage for injection into the air flow, wherein a fuel-air mixture generated by the swozzle assembly is directed into the combustion reaction zone in the combustion liner of the combustor. 
     
     
         15 . The combustor of  claim 9 , further comprising a central fuel supply line defined within the center member, and a central fuel injector at a downstream end of the central fuel supply line, the central fuel injector configured to mix a fuel other than ammonia with another air flow to generate a fuel-air mixture for combusting in the combustion reaction zone in the combustion liner of the combustor. 
     
     
         16 . A method of operating a combustor of a gas turbine system, the method comprising:
 in a combustor including a combustor body including a combustion liner; and a head end assembly including: a cap assembly, and a plurality of burners positioned in the cap assembly and directed into the combustion liner, at least one burner of the plurality of burners including a fuel-air mixing passage having a swozzle assembly including a plurality of turning vanes configured to impart a swirl to an air flow flowing through the fuel-air mixing passage, performing the following:   injecting ammonia with a plurality of ammonia injectors aimed upstream into the air flow in the fuel-air mixing passage at one or more axial locations downstream of the swozzle assembly to generate an ammonia-air mixture; and   combusting the ammonia-air mixture formed by the plurality of burners in a combustion reaction zone in the combustion liner.   
     
     
         17 . The method of  claim 16 , wherein the injecting ammonia into the air flow in the fuel-air mixing passage downstream of the swozzle assembly occurs at two different axial locations. 
     
     
         18 . The method of  claim 16 , wherein the injecting ammonia into the air flow in the fuel-air mixing passage downstream of the swozzle assembly includes injecting a first volume of ammonia at a first combustor load and a second, larger volume of ammonia at a second, larger combustor load.