Pilot burner assembly with central pilot fuel injection for a gas turbine engine combustor

Abstract

A pilot burner assembly for a combustion chamber in a gas turbine engine includes a pilot burner and a radial swirler. On a burner head face of the pilot burner, pilot fuel injection holes are present for providing pilot fuel. The swirler has swirler vanes arranged circumferentially and radially disposed around the burner head face with respect to a center of the burner head face. The swirler vanes have radially inner thin ends that define a burner region. Each pilot fuel injection hole is positioned such that a distance of the hole is equal to or less than 50 percent of a distance of an edge of the burner region, both distances measured from the center of the burner head face along a straight line from the center passing through the hole to the edge of the burner region.

1 . A pilot burner assembly for a combustion chamber in a gas turbine engine, the pilot burner assembly comprising:
 a pilot burner comprising a burner head face having a plurality of pilot fuel injection holes adapted to provide pilot fuel for combustion, wherein the burner head face has a center; and   a radial swirler adapted to generate a swirling mix of a main fuel and air, the radial swirler comprising a plurality of swirler vanes arranged circumferentially and radially disposed around the center of the burner head face; wherein the swirler vanes include radially inner thin ends that define a burner region and wherein the burner region is concentric with the center of the burner head face;   wherein each of the pilot fuel injection holes on the burner head face is positioned within the burner region such that a distance of the pilot fuel injection hole from the center of the burner head face is equal to or less than 50 percent of a distance of an edge of the burner region from the center of the burner head face when measured along a straight line that joins the center of the burner head face to the edge of the burner region passing through the pilot fuel injection hole.   
     
     
         2 . The pilot burner assembly according to  claim 1 ,
 wherein the distance of the pilot fuel injection hole from the center of the burner head face is equal to or less than 30 percent of the distance of the edge of the burner region from the center of the burner head face.   
     
     
         3 . The pilot burner assembly according to  claim 1 ,
 wherein the distance of the pilot fuel injection hole from the center of the burner head face is equal to or less than 15 percent of the distance of the edge of the burner region from the center of the burner head face.   
     
     
         4 . The pilot burner assembly according to  claim 1 ,
 wherein the distance of the pilot fuel injection hole from the center of the burner head face is equal to or greater than 5 percent of the distance of the edge of the burner region from the center of the burner head face.   
     
     
         5 . The pilot burner assembly according to  claim 1 ,
 wherein the distance of the pilot fuel injection hole from the center of the burner head face is equal to or greater than 10 percent of the distance of the edge of the burner region from the center of the burner head face.   
     
     
         6 . The pilot burner assembly according to  claim 1 ,
 wherein the burner region is circular.   
     
     
         7 . The pilot burner assembly according to  claim 1 ,
 wherein each of the pilot fuel injection holes is adapted to provide pilot fuel in a radially outwards direction.   
     
     
         8 . The pilot burner assembly according to  claim 7 ,
 wherein the radially outwards direction forms an angle with the burner head face between 30 degrees and 90 degrees.   
     
     
         9 . The pilot burner assembly according to  claim 7 ,
 wherein the plurality of the pilot fuel injection holes comprises at least a first pilot fuel injection hole and a second pilot fuel injection hole, each of the first and the second pilot fuel injection hole adapted to provide pilot fuel in the radially outwards direction at different angles with the burner head face.   
     
     
         10 . The pilot burner assembly according to  claim 1 ,
 wherein the pilot fuel injection holes are arranged in a two dimensional array.   
     
     
         11 . A combustor assembly for a gas turbine engine, the combustor assembly comprising:
 a combustion chamber having a longitudinal axis, and   a pilot burner assembly according to  claim 1 ,   wherein the pilot burner assembly is arranged such that the longitudinal axis of the combustion chamber is aligned with the center of the burner head face and wherein along the longitudinal axis the pilot burner, the radial swirler and the combustion chamber are serially arranged.   
     
     
         12 . A gas turbine engine comprising:
 at least one combustor assembly,   the at least one combustor assembly comprising a pilot burner assembly according to  claim 1 .   
     
     
         13 . The pilot burner assembly according to  claim 8 ,
 wherein the radially outwards direction forms an angle with the burner head face between 30 degrees and 60 degrees.