Method and apparatus for operating a burner of a heat engine, in particular of a gas turbine installation

Abstract

The invention describes a method and an apparatus for operating a burner of a heat engine, in particular of a gas turbine installation, having a burner inlet, to which a mixture of a fuel and an oxygen-enriched carrier gas is fed for combustion within a combustion chamber which adjoins the burner inlet in the direction of flow. The invention is distinguished by the following method steps: providing a first oxygen-enriched carrier gas stream, known as the first oxidizer mixture, with which the fuel is admixed to form a first fuel/oxidizer mixture, and providing a second oxygen-enriched carrier gas stream, known as the second oxidizer mixture, catalyzing the first fuel/oxidizer mixture to form a catalyzed first fuel/oxidizer mixture, in which the fuel is at least partially oxidized, mixing the catalyzed first fuel/oxidizer mixture with the second oxidizer mixture to form a second fuel/oxidizer mixture, and igniting and burning the second fuel/oxidizer mixture.

1 . A method for operating a burner of a heat engine, in particular of a gas turbine installation, having a burner inlet, to which a mixture of a fuel and an oxygen-enriched carrier gas is fed for combustion within a combustion chamber which adjoins the burner inlet in the direction of flow, comprising the following method steps: 
 providing a first oxygen-enriched carrier gas stream, known as the first oxidizer mixture, with which the fuel is admixed to form a first fuel/oxidizer mixture, and providing a second oxygen-enriched carrier gas stream, known as the second oxidizer mixture,    catalyzing the first fuel/oxidizer mixture to form a catalyzed first fuel/oxidizer mixture, in which the fuel is at least partially oxidized,    mixing the catalyzed first fuel/oxidizer mixture with the second oxidizer mixture to form a second fuel/oxidizer mixture, and    igniting and burning the second fuel/oxidizer mixture.    
     
     
         2 . The method as claimed in  claim 1 , wherein the first and second oxidizer mixtures are obtained in the following way: 
 recirculating at least some of the exhaust gas which emerges from the combustion chamber,    introducing the recirculated exhaust gas as carrier gas for taking up oxygen into an oxygen separation device for producing the oxygen-enriched carrier gas, known as the oxidizer mixture.    
     
     
         3 . The method as claimed in  claim 2 , wherein the oxidizer mixture is divided into the first oxidizer mixture and the second oxidizer mixture, and wherein the first oxidizer mixture is mixed with the fuel and brought into contact with catalyst material.  
     
     
         4 . The method as claimed in  claim 1 , wherein the oxidizer mixture provided is a gas mixture which substantially comprises the following constituents: O 2 , CO 2  and H 2 O, and wherein the fuel provided is gaseous fuel, preferably methane (CH 4 ).  
     
     
         5 . The method as claimed in  claim 1 , wherein the first fuel/oxidizer mixture has an oxygen ratio λ 1  and the second fuel/oxidizer mixture has an oxygen ratio λ 2 , and wherein the following relationship applies:  
         λ 1 <λ 2 ,  wherein the oxygen ratio is defined as the ratio of the actual oxygen supply to the minimum oxygen demand for complete combustion.    
     
     
         6 . The method as claimed in  claim 5 , characterized in that wherein the oxygen ratios λ 1  and λ 2  are set in such a manner that the following relationship applies: 0.2≦λ1≦0.5, preferably λ 1 ≈0.25, and λ 2 ≧1.  
     
     
         7 . The method as claimed in  claim 5 , wherein the fuel CH 4  contained within the first fuel/oxidizer mixture, during the catalysis, is at least partially converted into the reaction products H 2  and CO, which are contained in the catalyzed first fuel/oxidizer mixture and are mixed with the second oxidizer mixture without ignition phenomena occurring.  
     
     
         8 . The method as claimed in  claim 1 , wherein the second fuel/oxidizer mixture is reacted in a further catalytic converter.  
     
     
         9 . The method as claimed in  claim 1 , wherein the second fuel/oxidizer mixture is ignited and burnt within a premix burner.  
     
     
         10 . An apparatus for operating a burner of a heat engine, in particular of a gas turbine installation, having a burner inlet, to which a mixture of a fuel and an oxygen-enriched carrier gas, known as an oxidizer mixture, can be fed for combustion within a combustion chamber which adjoins the burner inlet in the direction of flow, characterized in that wherein at least one means for feeding in the oxidizer mixture and a fuel feed unit are provided in the region of the burner inlet, wherein a catalytic converter unit is provided in the region of the burner inlet, downstream of the means for feeding in the oxidizer mixture and of the fuel feed unit, and wherein at least one bypass line, which bypasses or passes through the catalytic converter unit and connects the region of the burner inlet upstream of the catalytic converter unit to the region of the burner inlet downstream of the catalytic converter unit, is provided.  
     
     
         11 . The apparatus as claimed in  claim 10 , wherein the catalytic converter unit is integrated in a support structure, which is provided downstream of the means for feeding in the oxidizer mixture and of the fuel feed unit, in the region of the burner inlet, and has a multiplicity of through-passages which are oriented in the direction of flow and a first group of which are provided with a catalyst material on the inner wall and constitute the catalytic converter unit, whereas a second group of through-passages consist of substantially chemically inert material which form at least one bypass line.  
     
     
         12 . The apparatus as claimed in  claim 11 , wherein the first and second groups of through-passages are arranged in a three-dimensionally periodic ordered pattern.  
     
     
         13 . The apparatus as claimed in  claim 11 , wherein the through-passages are arranged in matrix form within the support structure.  
     
     
         14 . The apparatus as claimed in  claim 12 , wherein the first and second groups are arranged in alternating rows, columns or in checkerboard pattern.  
     
     
         15 . The apparatus as claimed in  claim 10 , wherein the support structure is formed in the style of a honeycomb structure.  
     
     
         16 . The apparatus as claimed in  claim 10 , wherein at least one flow-guiding means, which spatially separates a first flow region from a second flow region, is provided upstream of the catalytic converter unit, wherein a mixture of fuel and oxidizer mixture can be introduced into the first flow region, and exclusively oxidizer mixture can be introduced into the second flow region, and wherein the first flow region is connected to the catalytic converter unit and the second flow region is connected to the bypass line.  
     
     
         17 . The apparatus as claimed in  claim 16 , wherein the flow-guiding means has a multiplicity of first and second flow regions, which are arranged in such a manner that the first flow regions are in communication with the catalytic converter unit and the second flow regions are in communication with the at least one bypass line.  
     
     
         18 . The apparatus as claimed in  claim 16 , wherein a perforated plate is arranged between the flow-guiding means and the catalytic converter unit.  
     
     
         19 . The apparatus as claimed in  claim 10 , wherein a further catalytic converter unit is provided downstream of the catalytic converter unit and upstream of the combustion chamber, to form a catalytic burner arrangement.  
     
     
         20 . The apparatus as claimed in  claim 10 , wherein a premix burner is arranged downstream of the first catalytic converter unit.  
     
     
         21 . The apparatus as claimed in  claim 10 , wherein the oxidizer mixture can be provided by the following components: 
 a recirculation line is used to pass some of the exhaust gases which emerge from the combustion chamber as carrier gas into an oxygen separation device, from which the oxygen-enriched carrier gas emerges and can be provided directly or indirectly via the means for feeding in oxidizer mixture and can be introduced into the at least one bypass line.    
     
     
         22 . The apparatus as claimed in  claim 21 , wherein the oxygen separation device has at least one MCM membrane.