Combustor

Abstract

A combustor includes an end cap that extends radially across at least a portion of the combustor, wherein the end cap comprises an upstream surface axially separated from a downstream surface. A shroud circumferentially surrounds at least a portion of the end cap, wherein the shroud at least partially defines a fuel plenum between the upstream surface and the downstream surface. A combustion chamber downstream from the end cap defines a longitudinal axis. A plurality of tubes extend from the upstream surface through the downstream surface of the end cap to provide fluid communication through the end cap to the combustion chamber. A transition duct circumferentially surrounds at least a portion of the combustion chamber downstream from the end cap and curves tangentially from the longitudinal axis.

What is claimed is: 
     
         1 . A combustor, comprising:
 a. an end cap that extends radially across at least a portion of the combustor, wherein the end cap comprises an upstream surface axially separated from a downstream surface;   b. a shroud that circumferentially surrounds at least a portion of the end cap, wherein the shroud at least partially defines a fuel plenum between the upstream surface and the downstream surface;   c. a combustion chamber downstream from the end cap, wherein the combustion chamber defines a longitudinal axis;   d. a plurality of tubes that extend from the upstream surface through the downstream surface of the end cap, wherein the plurality of tubes provide fluid communication through the end cap to the combustion chamber; and   e. a transition duct that circumferentially surrounds at least a portion of the combustion chamber downstream from the end cap, wherein the transition duct curves tangentially from the longitudinal axis.   
     
     
         2 . The combustor as in  claim 1 , further comprising a fuel port that provides fluid communication from the fuel plenum into one or more of the plurality of tubes. 
     
     
         3 . The combustor as in  claim 1 , further comprising an air plenum between the upstream and downstream surfaces and downstream from the fuel plenum. 
     
     
         4 . The combustor as in  claim 3 , further comprising one or more air ports that provide fluid communication through the shroud to the air plenum. 
     
     
         5 . The combustor as in  claim 1 , further comprising a fuel nozzle extending through the end cap, wherein the fuel nozzle provides fluid communication through the end cap to the combustion chamber. 
     
     
         6 . The combustor as in  claim 5 , wherein the plurality of tubes circumferentially surround the fuel nozzle. 
     
     
         7 . The combustor as in  claim 1 , further comprising a baffle extending axially from the upstream surface to the downstream surface, wherein the baffle separates the plurality of tubes into a plurality of tube bundles in the end cap. 
     
     
         8 . The combustor as in  claim 1 , wherein the transition duct curves radially from the longitudinal axis. 
     
     
         9 . A combustor, comprising:
 a. an end cap that extends radially across at least a portion of the combustor, wherein the end cap comprises an upstream surface axially separated from a downstream surface;   b. a fuel plenum between the upstream and downstream surfaces;   c. a transition duct downstream from the end cap, wherein the transition duct defines a longitudinal axis, a tangential axis, and a radial axis;   d. a plurality of tubes that extend from the upstream surface through the downstream surface of the end cap, wherein the plurality of tubes provide fluid communication through the end cap to the transition duct;   e. an inlet to the transition duct; and   f. an outlet to the transition duct displaced from the inlet along the longitudinal axis and the tangential axis.   
     
     
         10 . The combustor as in  claim 9 , further comprising an air plenum between the upstream and downstream surfaces and downstream from the fuel plenum. 
     
     
         11 . The combustor as in  claim 10 , further comprising one or more air ports that provide fluid communication through the end cap to the air plenum. 
     
     
         12 . The combustor as in  claim 10 , further comprising an air passage between one or more of the plurality of tubes and the downstream surface of the end cap. 
     
     
         13 . The combustor as in  claim 9 , further comprising a fuel nozzle extending through the end cap, wherein the fuel nozzle provides fluid communication through the end cap to the transition duct. 
     
     
         14 . The combustor as in  claim 9 , further comprising a baffle extending axially from the upstream surface to the downstream surface, wherein the baffle separates the plurality of tubes into a plurality of tube bundles in the end cap. 
     
     
         15 . The combustor as in  claim 9 , wherein the outlet to the transition duct is displaced from the inlet along the radial axis. 
     
     
         16 . A combustor, comprising:
 a. a fuel plenum;   b. a combustion chamber downstream from the fuel plenum, wherein the combustion chamber defines a longitudinal axis;   c. a plurality of tubes that provide fluid communication from the fuel plenum to the combustion chamber;   d. a transition duct that circumferentially surrounds at least a portion of the combustion chamber downstream from the plurality of tubes, wherein the transition duct curves tangentially from the longitudinal axis.   
     
     
         17 . The combustor as in  claim 16 , further comprising an air plenum between the fuel plenum and the combustion chamber. 
     
     
         18 . The combustor as in  claim 16 , wherein the transition duct curves radially from the longitudinal axis. 
     
     
         19 . The combustor as in  claim 16 , further comprising a baffle extending axially through the fuel plenum, wherein the baffle separates the plurality of tubes into a plurality of tube bundles. 
     
     
         20 . The combustor as in  claim 16 , further comprising a fuel nozzle in fluid communication with the combustion chamber, wherein the plurality of tubes circumferentially surround the fuel nozzle.