Burner, gas turbine combustor, burner cooling method, and burner modifying method

Abstract

In a burner for injecting mixed gas fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, the burner includes a fuel nozzle for startup from which liquid fuel is injected into the combustion chamber, and a mixed fuel nozzle disposed around the fuel nozzle for injecting the mixed gas fuel. An air swirler is disposed at a downstream end of the mixed fuel nozzle and has a plurality of flow passages from which compressed air is injected into the combustion chamber, and the mixed fuel nozzle has injection ports disposed in the inner peripheral side of the flow passages of the air swirler. Cooling holes formed in the nozzle surface and positioned to face the combustion chamber introduce a part of the mixed gas fuel injected from the mixed fuel nozzle into the combustion chamber.

1 . A burner for injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said burner comprising: 
 a fuel nozzle for startup from which fuel for startup is injected into said combustion chamber;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel;    an air swirler disposed at a downstream end of said mixed fuel nozzle positioned in said combustion chamber and having a plurality of flow passages through which a part of compressed air from a compressor is injected into said combustion chamber to hold a flame, said mixed fuel nozzle having injection ports disposed in the inner peripheral side of the flow passages of said air swirler; and    cooling holes formed in a nozzle surface positioned to face said combustion chamber and introducing a part of the mixed fuel injected from said mixed fuel nozzle into said combustion chamber, to thereby reduce flame temperature near the nozzle surface.    
   
   
       2 . The burner according to  claim 1 , wherein said fuel nozzle for startup comprises a liquid fuel nozzle for injecting liquid fuel for the startup of said gas turbine, and an atomizing air nozzle disposed around said liquid fuel nozzle and injecting atomizing air to atomize the liquid fuel.  
   
   
       3 . The burner according to  claim 1 , wherein said fuel nozzle for startup is disposed at a center of a combustion liner forming said combustion chamber in the radial direction.  
   
   
       4 . The burner according to  claim 1 , further comprising an inert gas supply system for supplying inert gas to said fuel nozzle for startup, wherein the inert gas from said inert gas supply system is supplied to said fuel nozzle for startup such that the inert gas is injected to the vicinity of the nozzle surface from said fuel nozzle for startup during a gas combustion mode using only the mixed fuel.  
   
   
       5 . The burner according to  claim 1 , wherein the mixed fuel is any of coke oven gas, blast furnace gas, LD gas, coal, and heavy oil gasification gas.  
   
   
       6 . A gas turbine combustor for burning mixed fuel containing at least one of hydrogen and carbon monoxide, said combustor comprising: 
 an outer casing serving as a pressure vessel;    a combustion liner disposed inside said outer casing and forming a combustion chamber therein;    a burner for forming a flame in said combustion chamber within said combustion liner; and    a transition piece for introducing, to a turbine, burned gas generated with the formation of the flame by said burner,    said burner comprising:    a fuel nozzle for startup from which fuel for startup is injected into said combustion chamber;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel;    an air swirler disposed at a downstream end of said mixed fuel nozzle positioned in said combustion chamber and having a plurality of flow passages through which a part of compressed air from a compressor is injected into said combustion chamber to hold a flame, said mixed fuel nozzle having injection ports disposed in the inner peripheral side of the flow passages of said air swirler; and    cooling holes formed in a nozzle surface positioned to face said combustion chamber and introducing a part of the mixed fuel injected from said mixed fuel nozzle into said combustion chamber, to thereby reduce flame temperature near the nozzle surface.    
   
   
       7 . A method of cooling a burner employing a diffusive combustion system and injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said method comprising the steps of: 
 forming cooling holes in a nozzle surface positioned to face said combustion chamber such that a part of the mixed fuel is injected through said cooling holes; and    injecting the part of the mixed fuel into said combustion chamber through said cooling holes, to thereby reduce flame temperature near the nozzle surface and suppress a rise of metal temperature at the nozzle surface.    
   
   
       8 . A burner for injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said burner comprising: 
 a fuel nozzle for startup which comprises a liquid fuel nozzle for injecting liquid fuel for the startup of said gas turbine, and an atomizing air nozzle disposed around said liquid fuel nozzle and injecting atomizing air to atomize the liquid fuel;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel;    an air swirler disposed at a downstream end of said mixed fuel nozzle positioned in said combustion chamber and injecting a part of compressed air from a compressor into said combustion chamber to hold a flame; and    an inert gas supply system for supplying inert gas to said fuel nozzle for startup,    wherein the inert gas from said inert gas supply system is supplied to said fuel nozzle for startup such that the inert gas is injected to the vicinity of a nozzle surface from said fuel nozzle for startup during a gas combustion mode using only the mixed fuel.    
   
   
       9 . A gas turbine combustor for burning mixed fuel containing at least one of hydrogen and carbon monoxide, said combustor comprising: 
 an outer casing serving as a pressure vessel;    a combustion liner disposed inside said outer casing and forming a combustion chamber therein;    a burner for forming a flame in said combustion chamber within said combustion liner; and    a transition piece for introducing, to a turbine, burned gas generated with the formation of the flame by said burner,    said burner comprising:    a fuel nozzle for startup which comprises a liquid fuel nozzle for injecting liquid fuel for the startup of said gas turbine, and an atomizing air nozzle disposed around said liquid fuel nozzle and injecting atomizing air to atomize the liquid fuel;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel;    an air swirler disposed at a downstream end of said mixed fuel nozzle positioned in said combustion chamber and injecting a part of compressed air from a compressor into said combustion chamber to hold a flame; and    an inert gas supply system for supplying inert gas to said fuel nozzle for startup,    wherein the inert gas from said inert gas supply system is supplied to said fuel nozzle for startup such that the inert gas is injected to the vicinity of a nozzle surface from said fuel nozzle for startup during a gas combustion mode using only the mixed fuel.    
   
   
       10 . A method of cooling a burner employing a diffusive combustion system and injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said method comprising the steps of: 
 providing a mixed fuel nozzle for injecting the mixed fuel to be disposed around a fuel nozzle for startup from which fuel for startup is injected into said combustion chamber; and    supplying inert gas from an inert gas supply system to said fuel nozzle for startup such that the inert gas is injected to the vicinity of a nozzle surface from said fuel nozzle for startup during a gas combustion mode using only the mixed fuel, thereby reducing flame temperature near the nozzle surface and suppressing a rise of metal temperature at the nozzle surface.    
   
   
       11 . A burner for injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said burner comprising: 
 a fuel nozzle for startup from which fuel for startup is injected into said combustion chamber;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel;    an air swirler disposed at a downstream end of said mixed fuel nozzle positioned in said combustion chamber and having a plurality of flow passages through which a part of compressed air from a compressor is injected into said combustion chamber to hold a flame, said mixed fuel nozzle having injection ports disposed in the inner peripheral side of the flow passages of said air swirler; and    means for purging the fuel residing in said fuel nozzle for startup.    
   
   
       12 . The burner according to  claim 11 , wherein said means for purging the fuel includes a system for supplying a part of the mixed fuel, which is supplied to said mixed fuel nozzle, to said fuel nozzle for startup.  
   
   
       13 . A burner for injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said burner comprising: 
 a fuel nozzle for startup from which fuel for startup is injected into said combustion chamber;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel;    a swirler disposed to face said combustion chamber and including an air swirler disposed at a downstream end of said mixed fuel nozzle positioned in said combustion chamber and having a plurality of flow passages through which a part of compressed air from a compressor is injected into said combustion chamber to hold a flame, said mixed fuel nozzle having injection ports disposed in the inner peripheral side of the flow passages of said air swirler; and    means for reducing flame temperature in the vicinity of said swirler disposed to face said combustion chamber to be lower than the melting point of a swirler material.    
   
   
       14 . A method of modifying a burner for injecting mixed fuel containing at least one of hydrogen and carbon monoxide into a combustion chamber of a gas turbine combustor, said burner comprising: 
 a fuel nozzle for startup which comprises a liquid fuel nozzle for injecting liquid fuel for the startup of said gas turbine, and an atomizing air nozzle disposed around said liquid fuel nozzle and injecting atomizing air to atomize the liquid fuel;    a mixed fuel nozzle disposed around said fuel nozzle for startup and injecting the mixed fuel; and    a plurality of flow passages which are formed in a downstream end of said mixed fuel nozzle positioned in said combustion chamber and through which a part of compressed air from a compressor is injected into said combustion chamber to hold a flame,    said method including the step of additionally providing, on said burner, means for supplying inert gas to said atomizing air nozzle.