Combustion chamber of a gas turbine, gas turbine and method for operating the same

Abstract

A combustion chamber assembly of a gas turbine, for combusting a fuel in the presence of combustion air, includes: a combustion chamber, in which combustion of fuel occurs; a precombustion chamber upstream of the combustion chamber; an atomization device that feeds a liquid fuel to the precombustion chamber; and a swirl body that feeds combustion air and gaseous fuel to the precombustion chamber. The combustion chamber assembly is configured as a dual-fuel combustion chamber assembly, which, in a gas fuel operating mode, feeds a mixture of a gaseous fuel and combustion air to the combustion chamber via the swirl body, and which, in a liquid fuel operating mode, feeds liquid fuel to the combustion chamber via the atomization device and combustion air to the combustion chamber via the swirl body. The atomization device includes an atomization lance with a central atomization nozzle, and plural decentralized atomization nozzles.

What is claimed is: 
     
         1 . A combustion chamber assembly of a gas turbine, for combusting a fuel in the presence of combustion air, the combustion chamber assembly comprising:
 a combustion chamber ( 1 ), in which combustion of fuel occurs, the combustion chamber ( 1 ) being delimited by a wall ( 2 );   a precombustion chamber ( 9 ), arranged upstream, in a fuel feeding direction, of the combustion chamber ( 1 );   an atomization device ( 4 ) configured to feed a liquid fuel to the precombustion chamber ( 9 ); and   a swirl body ( 3 ) configured to feed combustion air and gaseous fuel to the precombustion chamber ( 9 ),   wherein:   the combustion chamber assembly is configured as a dual-fuel combustion chamber assembly, which, in a gas fuel operating mode, feeds a mixture of a gaseous fuel and combustion air to the combustion chamber ( 1 ) via the swirl body ( 3 ), and which, in a liquid fuel operating mode, feeds liquid fuel to the combustion chamber ( 1 ) via the atomization device ( 4 ) and combustion air to the combustion chamber ( 1 ) via the swirl body ( 3 ), and   the atomization device ( 4 ) comprises:
 an atomization lance ( 17 ) with at least one atomization nozzle ( 15 ,  16 ), the atomization lance ( 17 ) being centrally arranged in the combustion chamber assembly with respect to a longitudinal center axis ( 20 ) of the combustion chamber assembly ( 1 ), and 
 a plurality of atomization nozzles ( 18 ), the plurality of atomization nozzles ( 18 ) being arranged in the combustion chamber assembly in a decentralized manner with respect to the longitudinal center axis ( 20 ) of the combustion chamber assembly. 
   
     
     
         2 . The combustion chamber assembly according to  claim 1 , wherein the decentralized atomization nozzles ( 18 ) are arranged on a circular path ( 19 ) extending about the longitudinal center axis ( 20 ). 
     
     
         3 . The combustion chamber assembly according to  claim 2 , wherein a center point of the circular path ( 19 ), on which the decentralized atomization nozzles ( 18 ) are arranged, is positioned on the longitudinal center axis ( 20 ). 
     
     
         4 . The combustion chamber assembly according to  claim 3 , wherein the circular path ( 19 ), on which the decentralized atomization nozzles ( 18 ) are arranged, has a radius of between 0.4 times and 1.1 times an inner radius of the swirl body ( 3 ). 
     
     
         5 . The combustion chamber assembly according to  claim 1 , wherein:
 the centrally arranged atomization lance ( 17 ) comprises two atomization nozzles ( 15 ,  16 ) which, alone and jointly, provide an atomization cone ( 8   a ) with a maximum spray angle (α) of 60° in each case, and   each of the decentralized atomization nozzles ( 18 ) provides an atomization cone ( 8   b ) with a maximum spray angle (β) of 50°.   
     
     
         6 . The combustion chamber assembly according to  claim 1 , wherein the centrally arranged atomization lance ( 17 ) is surrounded by an adjoining component ( 5 ) at least in sections, so as to form therebetween a radial gap ( 6 ) radially outside the centrally arranged atomization lance ( 17 ), the combustion chamber ( 1 ) being suppliable with combustion air via the radial gap ( 6 ) while bypassing the swirl body ( 3 ). 
     
     
         7 . The combustion chamber assembly according to  claim 6 , wherein the combustion air flow fed via the radial gap ( 6 ) comprises between 1% and 10% of the combustion air flow that is feedable to the combustion chamber ( 1 ) via the swirl body ( 3 ). 
     
     
         8 . The combustion chamber assembly according to  claim 7 , wherein the radial gap ( 6 ) is configured to supply the combustion chamber ( 1 ) with combustion air both in the gas fuel operating mode and in the liquid fuel operating mode. 
     
     
         9 . A gas turbine comprising:
 a combustion chamber assembly according to  claim 1 ; and   a turbine for expanding exhaust gas created during combustion in the combustion chamber assembly.   
     
     
         10 . A method for operating a gas turbine according to  claim 9 , comprising:
 supplying the combustion chamber ( 1 ) in the gas fuel operating mode with a mixture of a gaseous fuel and combustion air via the swirl body ( 3 ), and   supplying the combustion chamber ( 1 ) in the liquid fuel operating mode with a liquid fuel via the atomization device ( 4 ) and combustion air at least via the swirl body ( 3 ).   
     
     
         11 . The method according to  claim 10 , wherein in the liquid fuel operating mode both the centrally arranged atomization lance ( 17 ) and the decentralized atomization nozzles ( 18 ) are utilized, throughout an operating range between a no load state and a full load state, to supply the combustion chamber ( 1 ) with the liquid fuel. 
     
     
         12 . The method according to  claim 11 , wherein via the centrally arranged atomization lance ( 17 ), throughout the operating range between the no load state and the full load state, a constant quantity of liquid fuel is supplied to the combustion chamber ( 1 ), and wherein power modulation is carried out by changing a quantity of the liquid fuel fed to the combustion chamber ( 1 ) via the decentralized atomization nozzles ( 18 ). 
     
     
         13 . The method according to  claim 10 , wherein in the liquid fuel operating mode, in an operating range below a predetermined load limit, both the centrally arranged atomization lance ( 17 ) and the decentralized atomization nozzles ( 18 ) are utilized to supply the liquid fuel to the combustion chamber ( 1 ), whereas in an operating range above the predetermined load limit the decentralized atomization nozzles are utilized ( 18 ) exclusively for supplying the liquid fuel to the combustion chamber ( 1 ). 
     
     
         14 . The method according to  claim 13 , wherein in the operating range below the predetermined load limit a constant quantity of liquid fuel is supplied via the centrally arranged atomization lance ( 17 ), wherein power modulation is carried out by changing a quantity of the liquid fuel supplied to the combustion chamber ( 1 ) via the decentralized atomization nozzles ( 18 ).