Combustor and method for supplying fuel to a combustor

Abstract

A combustor includes an end cap having an upstream surface axially separated from a downstream surface. A casing circumferentially surrounds at least a portion of the end cap to define an annular passage. A first tube bundle extends from the upstream surface through the downstream surface to provide fluid communication through the end cap. A first fuel conduit is in fluid communication with the first tube bundle to supply fuel through the annular passage to the first tube bundle, and a liquid fuel supply is in fluid communication with the first tube bundle through the first fuel conduit. A method for supplying fuel to a combustor includes flowing a working fluid through a first tube bundle and flowing a liquid fuel through an annular passage surrounding the end cap and into the first tube bundle.

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 casing circumferentially surrounding at least a portion of the end cap to define an annular passage between the end cap and the casing;   c. a first tube bundle that extends from the upstream surface through the downstream surface to provide fluid communication through the end cap;   d. a first fuel conduit in fluid communication with the first tube bundle to supply fuel through the annular passage to the first tube bundle; and   e. a liquid fuel supply in fluid communication with the first tube bundle through the first fuel conduit.   
     
     
         2 . The combustor as in  claim 1 , wherein the first fuel conduit comprises a radially extending fuel line for each tube in the first tube bundle. 
     
     
         3 . The combustor as in  claim 2 , wherein each radially extending fuel line terminates upstream from the first tube bundle. 
     
     
         4 . The combustor as in  claim 2 , wherein each radially extending fuel line includes a fuel port aligned with an axial centerline of each tube in the first tube bundle. 
     
     
         5 . The combustor as in  claim 1 , further comprising a second tube bundle that extends from the upstream surface through the downstream surface to provide fluid communication through the end cap and a second fuel conduit in fluid communication with the second tube bundle to supply fuel to the second tube bundle. 
     
     
         6 . The combustor as in  claim 5 , wherein the second fuel conduit supplies fuel through the annular passage to the second tube bundle. 
     
     
         7 . The combustor as in  claim 5 , further comprising a third fuel conduit in fluid communication with the first tube bundle to supply fuel through the annular passage to the first tube bundle. 
     
     
         8 . The combustor as in  claim 5 , further comprising a shroud that circumferentially surrounds the second fuel conduit, wherein the shroud provides fluid communication through the end cap. 
     
     
         9 . The combustor as in  claim 9 , further comprising a swirler vane that extends between the shroud and the second fuel conduit. 
     
     
         10 . 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 casing circumferentially surrounding at least a portion of the end cap to define an annular passage between the end cap and the casing;   c. a plurality of tubes that extend from the upstream surface through the downstream surface to provide fluid communication through the end cap;   d. a barrier that extends axially through the end cap to separate the plurality of tubes into a first tube bundle and a second tube bundle;   e. a first fuel conduit in fluid communication with the first tube bundle to supply fuel through the annular passage to the first tube bundle; and   f. a liquid fuel supply in fluid communication with the first tube bundle through the first fuel conduit.   
     
     
         11 . The combustor as in  claim 10 , wherein the first fuel conduit comprises a radially extending fuel line for each tube in the first tube bundle. 
     
     
         12 . The combustor as in  claim 11 , wherein each radially extending fuel line terminates upstream from the first tube bundle. 
     
     
         13 . The combustor as in  claim 11 , wherein each radially extending fuel line includes a fuel port aligned with an axial centerline of each tube in the first tube bundle. 
     
     
         14 . The combustor as in  claim 10 , further comprising a second fuel conduit in fluid communication with the second tube bundle to supply fuel to the second tube bundle. 
     
     
         15 . The combustor as in  claim 14 , wherein the second fuel conduit supplies fuel through the annular passage to the second tube bundle. 
     
     
         16 . The combustor as in  claim 14 , further comprising a third fuel conduit in fluid communication with the first tube bundle to supply fuel through the annular passage to the first tube bundle. 
     
     
         17 . The combustor as in  claim 14 , further comprising a shroud that circumferentially surrounds the second fuel conduit, wherein the shroud provides fluid communication through the end cap. 
     
     
         18 . The combustor as in  claim 17 , further comprising a swirler vane that extends between the shroud and the second fuel conduit. 
     
     
         19 . A method for supplying fuel to a combustor, comprising:
 a. flowing a working fluid through a first tube bundle that extends axially through an end cap that extends radially across at least a portion of the combustor; and   b. flowing a liquid fuel through an annular passage surrounding the end cap and into the first tube bundle.   
     
     
         20 . The method as in  claim 19 , further comprising spraying the liquid fuel into the axial center of each tube in the first tube bundle.