Annular combustion chamber for a gas turbine

Abstract

An annular combustion chamber for a gas turbine is disclosed, which permits a sealed air cooling, such that high powers and efficiencies can be achieved with low NOx emissions. The two-piece annular combustion chamber housing surrounds a thin-walled sealed liner, which guides the hot gas escaping from the burners to the turbine inlet in a gas-tight manner. A variable annular chamber is located between the liner and the annular combustion chamber housing, in which the cooling air is collected as a counter-current to the hot gas and fed to the burners (closed air cooling). The surfaces of the liner are variably cooled with efficient baffle cooling devices and drilled patterns in. The thermally-elastic liner constructed from submerged arc-welded rings is axially fixed at the flange only and for the remainder provided with reinforcing circumferential beading. The freely expanding liner is otherwise concentrically fixed to the cold annular combustion chamber housing by means of elastic tensioning elements. The above efficient, economical and simple construction further offers significant service advantages due to the following construction features: the burners can be completely (dis)assembled from outside without opening the housing. Both the liner and also a ring which integrates the first row of turbine guide vanes in the annular combustion chamber can be removed as service pieces in other words exchanged without opening the turbine and compressor housing and without removal of a rotor.

1 - 19 . (canceled).  
     
     
         20 . An annular combustion chamber for a gas turbine, comprising: 
 an annular outer wall;    an annular inner liner arranged coaxially within the annular outer wall;    an annular chamber arranged between the inner liner and the outer wall adapted to allow the passage of a cooling medium;    an inlet to receive a flow of fuel/air mixture; and    an outlet to exhaust a combusted fuel/air mixture.    
     
     
         21 . The annular combustion chamber according to  claim 20 , wherein the inner liner comprises reinforcing structures.  
     
     
         22 . The annular combustion chamber according to  claim 20 , wherein the cooling air for a closed air cooling system can be directed through the annular chamber.  
     
     
         23 . The annular combustion chamber according to  claim 20 , wherein the liner is made of a thin metal sheet.  
     
     
         24 . The annular combustion chamber according to  claim 23 , wherein the liner is made of individual annular segments welded together, preferably by submerged arc welding.  
     
     
         25 . The annular combustion chamber according to  claim 20 , wherein the liner is fixed in relation to the outer wall at the point of transition from the annular combustion chamber to the turbine chamber and is also supported on the outer wall such that it can be moved in relation to it, with elastic hangers distributed along its surface.  
     
     
         26 . The annular combustion chamber according to  claim 25 , wherein the elastic hangers are formed by connections arranged in such a manner that they can be displaced in a relative manner between the liner and the outer wall and spring-loaded in the direction of the outer wall.  
     
     
         27 . The annular combustion chamber according to  claim 25 , wherein the elastic hangers comprise friction dampers.  
     
     
         28 . The annular combustion chamber according to  claim 20 , wherein the reinforcing structures are in the form of reinforcing beading.  
     
     
         29 . The annular combustion chamber according to  claim 28 , wherein the reinforcing beading runs along a circumference of the liner.  
     
     
         30 . The annular combustion chamber according to  claim 28 , wherein the reinforcing beading has a geometry that is selected to vary over a longitudinal extension of the liner.  
     
     
         31 . The annular combustion chamber according to  claim 20 , wherein the liner and/or the outer wall is made from at least two components separated from each other in the axial direction, which are connected together by means of flanged connections.  
     
     
         32 . The annular combustion chamber according to  claim 20 , wherein the liner comprises a coating on its surfaces exposed to the hot gas, preferably a heat insulation coating or an anti-oxidation coating.  
     
     
         33 . The annular combustion chamber according to  claim 20 , wherein the point of entry for the burner into the liner is sealed by means of a piston ring seal.  
     
     
         34 . The annular combustion chamber according to  claim 20 , wherein the combustion chamber has structures to baffle cool the liner.  
     
     
         35 . The annular combustion chamber according to  claim 34 , wherein the baffle cooling segments in the area of an inlet zone, in which the burner opens into the liner.  
     
     
         36 . The annular combustion chamber according to  claim 20 , wherein the outer wall comprises reinforcing structures, preferably reinforcing ribs.  
     
     
         37 . The annular combustion chamber according to  claim 20 , wherein the passage of the burner through the outer wall is sealed by means of a labyrinth seal.  
     
     
         38 . The annular combustion chamber according to  claim 20 , wherein the first turbine vane ring is connected to the annular combustion chamber.  
     
     
         39 . A gas turbine, comprising: 
 an annular combustion chamber, comprising: 
 an annular outer wall,  
 an annular inner liner, arranged coaxially within the annular outer wall, and  
 an annular chamber arranged between the inner liner and the outer wall adapted to allow the passage of a cooling medium,  
   an inlet adapted to receive a flow of fuel/air mixture operatively connected to the combustion chamber; and    an outlet adapted to exhaust a combusted fuel/air mixture operatively connected to the combustion chamber.