Combustor and cap assemblies for combustors in a gas turbine

Abstract

The cap assembly of a turbine combustor includes a plurality of burner tubes sealed against fuel nozzles extending in the tubes. These piston seals are coated with a high velocity oxygen fuel coating to extend their service life. The outer cap body assembly includes concentric seal rings each with cantilevered convex fingers circumferentially offset from one another to seal between the cap assembly casing and the inner liner. The cap assembly casing is provided with a plurality of holes at predetermined locations about the casing to minimize or eliminate response to combustion dynamics.

1 . A cap assembly for a turbine combustor comprising: 
 a plurality of burner tubes;    a fuel nozzle in each burner tube; and    seals between the burner tubes and the fuel nozzles, each seal including a ring having a high velocity oxygen fuel coating on a surface thereof.    
   
   
       2 . A cap assembly according to  claim 1  wherein said seal is formed of HAST-X.  
   
   
       3 . A combustor comprising: 
 a combustor liner;    a cap assembly in part received within an end of the liner; and    a seal between the cap assembly and said liner including pair of generally annular rings, each said ring having a plurality of spring fingers at circumferentially spaced locations thereabout, said rings being concentrically disposed relative to one another with the spring fingers of one ring circumferentially offset from the spring fingers of another ring enabling the spring fingers of each ring to register with gaps between the spring fingers of said another ring.    
   
   
       4 . A combustor according to  claim 3  wherein each ring has a margin along an edge thereof with the spring fingers cantilevered from said edge.  
   
   
       5 . A combustor according to  claim 4  wherein the spring fingers are arcuate with each spring finger following the arcuate contour of registering portions of a pair of spring fingers of said another ring.  
   
   
       6 . A combustor according to  claim 5  wherein the spring fingers are secured to a casing of the cap assembly, said spring fingers of an outermost ring having radially outward cantilevered convex portions for sealing about an inner surface of the liner.  
   
   
       7 . A combustor according to  claim 6  wherein said radially outward convex portions have a high velocity oxygen fuel coating.  
   
   
       8 . A cap assembly for a turbine combustor comprising: 
 a plurality of burner tubes;    a fuel nozzle in each burner tube;    an outer body sleeve surrounding said plurality of burner tubes and having a plurality of openings sized and located to protect against onset of a mode of combustion dynamics.