Combustor for a gas turbine

Abstract

A combustor for a gas turbine having: a pre-combustion chamber, a swirler, a pilot burner upstream the pre-combustion chamber which has a pilot burner surface separating the pilot burner from the pre-combustion chamber. The pilot burner further includes at least a pilot fuel injector, wherein the combustor includes a lip extending from the pilot burner surface in the pre-combustion chamber, the lip including an internal surface oriented towards the pilot fuel injector, the internal surface being inclined of an inclination angle of between 0 degrees and 90 degrees with respect to the center axis of the pre-combustion chamber, and the lip has at least a feed passage for connecting the internal surface with the flow of oxidant gas coming from the swirler.

1 . A combustor for a gas turbine, comprising:
 a pre-combustion chamber,   a swirler which is connected to the pre-combustion chamber providing pre-combustion chamber with a flow of fuel and oxidant gas, the swirler being arranged around the pre-combustion chamber in a circumferential direction with respect to a centre axis of the pre-combustion chamber,   a pilot burner upstream the pre-combustion chamber which comprises a pilot burner surface separating the pilot burner from the pre-combustion chamber, the pilot burner further comprising at least a pilot fuel injector which is arranged to the pilot burner surface for injecting pilot fuel into the pre-combustion chamber, wherein the combustor includes a lip extending from the pilot burner surface in the pre-combustion chamber, the lip including an internal surface oriented towards the pilot fuel injector for intercepting at least part of the pilot fuel from the pilot fuel injector, the internal surface being inclined of an inclination angle (α) with respect to the centre axis of the pre-combustion chamber, the inclination angle (α) being comprised between 0 degrees and 90 degrees, and   wherein the lip comprises at least a feed passage connecting the internal surface with the flow of oxidant gas coming from the swirler.   
     
     
         2 . The combustor according to  claim 1 ,
 wherein the lip further comprises an external surface oriented towards the swirler intercepting at least part of the flow coming from the swirler, the feed passage being provided between the internal surface and the external surface.   
     
     
         3 . The combustor according to  claim 2 ,
 wherein the external surface comprises a plurality of turbulators inducing turbulence in at least part of the flow of oxidant gas coming from the swirler.   
     
     
         4 . The combustor according to  claim 3 ,
 wherein the turbulators comprise a plurality of protrusions extending orthogonally from the external surface.   
     
     
         5 . The combustor according to  claim 3 ,
 wherein the protrusions comprise a circular rim, the circular rim being concentric with the centre axis of the pre-combustion chamber.   
     
     
         6 . The combustor according to  claim 3 ,
 wherein the turbulators comprise a plurality of channels having a depth extending from the external surface towards the internal surface.   
     
     
         7 . The combustor according to  claim 2 ,
 wherein internal surface and the external surface have a common trailing edge.   
     
     
         8 . The combustor according to  claim 7 ,
 wherein the trailing edge has a circular profile around the centre axis of the pre-combustion chamber.   
     
     
         9 . The combustor according to  claim 7 ,
 wherein the trailing edge has a waved profile.   
     
     
         10 . The combustor according to  claim 1 ,
 wherein the internal surface has an aerofoil shape.   
     
     
         11 . The combustor according to  claim 1 ,
 wherein the value of the inclination angle (α) is comprised between 30° and 60°.   
     
     
         12 . The combustor according to  claim 1 ,
 wherein the lip extends from a portion of the pilot burner surface whose distance from the centre axis of the pre-combustion chamber is greater than the distance between the pilot fuel injector and the centre axis.   
     
     
         13 . The combustor according to  claim 1 ,
 wherein the lip is provided as an edge of a shroud of the pilot burner extending inside the pre-combustion chamber.   
     
     
         14 . The combustor according to  claim 1 ,
 wherein the lip comprises a plurality of feed passages connecting the internal surface with the flow of oxidant gas coming from the swirler, the feed passages being regularly distributed around the centre axis.