Burner for a gas turbine

Abstract

A burner for a gas turbine includes a burner housing, and a pilot combustor having a supply module providing pilot fuel and pilot air into a pilot combustion room being enclosed by a pilot combustor housing having a tapered exit with a throat of a defined length into the resulting main flow direction. The throat discharges a concentration of radicals are and heat generated in the pilot combustion room into a main combustion room enclosed by the burner housing. The interior cross section area of the throat deviates from a circle by means of flow guiding elements provided as protrusions with a defined radial height or as recesses with a defined depth extending longitudinally along the direction of the burner axis to give the discharging flow a defined velocity distribution with regard to a circumferential direction.

1 - 10 . (canceled) 
     
     
         11 . A burner for a gas turbine, comprising:
 a burner housing, and   a pilot combustor, comprising a supply module providing pilot fuel and pilot air into a pilot combustion room being enclosed by a pilot combustor housing comprising a tapered exit with a throat of a defined length into the resulting main flow direction, said throat discharging a concentration of radicals are and heat generated in said pilot combustion room into a main combustion room enclosed by said burner housing,   wherein a burner axis is defined by a centre line of said throat extending in the direction of the resulting main flow through said throat,   wherein the interior cross section area of said throat deviates from a circle by means of flow guiding elements provided as protrusions with a defined radial height or as recesses with a defined depth extending longitudinally along the direction of the burner axis to give the discharging flow a defined velocity distribution with regard to a circumferential direction.   
     
     
         12 . The burner according to  claim 11 , wherein said cross section protrusions or recesses form a cross or a star shape of said radial cross-section of the throat. 
     
     
         13 . The burner according to  claim 11 , wherein said cross-section forms a triangle, a quadrangle, a pentagon or another polygon without being a circle. 
     
     
         14 . The burner according to  claim 11 , wherein said cross-section comprises convex or concave portions of an inner surface of said throat. 
     
     
         15 . The burner according to  claim 11 , wherein said protrusions and/or recesses are provided with a helical shape extending along the centre line to give the flow through the throat a swirl. 
     
     
         16 . The burner according to  claim 11 , wherein said protrusions and/or recesses are essentially parallel to said burner axis to give the flow a velocity distribution without a swirl. 
     
     
         17 . The burner according to  claim 15 , wherein said burner comprises a swirler discharging air or/and fuel into said main combustion room establishing a main swirl in said main combustion room of a first direction, wherein the protrusions and/or the recesses are formed such that the flow exiting the throat is given a counterwise swirl with regard to the swirl in the main combustion room. 
     
     
         18 . The burner according to  claim 11 , wherein the throat is provided with nozzles for discharging fuel into the flow through the throat. 
     
     
         19 . The burner according to  claim 18 , wherein said nozzles are located on flanks of said protrusions and/or recesses. 
     
     
         20 . The burner according to  claim 18 , wherein said nozzles (NOZ) are made for gaseous fuel to be injected into said flow through said throat.