Method for operating a combustion system

Abstract

A method for operating a combustion system of a combustion section of a gas turbine engine having at least one main burner arrangement and at least one pilot burner arrangement, wherein the at least one main burner arrangement and the at least one pilot burner arrangement are operated with an air-fuel mixture. The method includes: operating the at least one main burner arrangement with O 2 -lean air, enriching an air of the air-fuel mixture of the at least one pilot burner arrangement and/or a fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or the air-fuel mixture of the at least one pilot burner arrangement with oxygen and preferably with pure oxygen.

1 . A method for operating a combustion system of a combustion section of a gas turbine engine comprising at least one main burner arrangement and at least one pilot burner arrangement, wherein the at least one main burner arrangement and the at least one pilot burner arrangement are operated with an air-fuel mixture,
 wherein the method comprises:   operating the at least one main burner arrangement with O 2 -lean air,   enriching an air of the air-fuel mixture of the at least one pilot burner arrangement and/or a fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or the air-fuel mixture of the at least one pilot burner arrangement with oxygen.   
     
     
         2 . The method according to  claim 1 , further comprising:
 enriching the air of the air-fuel mixture of the at least one pilot burner arrangement and/or the fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or the air-fuel mixture of the at least one pilot burner arrangement with oxygen so that an oxygen content of the air-fuel mixture burned by the at least one pilot burner arrangement is at least 5% higher than an oxygen content of the air feed to the at least one pilot burner arrangement beforehand of a mixing with the oxygen.   
     
     
         3 . The method according to  claim 1 ,
 wherein the air of the air-fuel mixture of the at least one pilot burner arrangement beforehand of the mixing with oxygen is O 2 -lean air.   
     
     
         4 . The method according to  claim 3 , further comprising:
 providing the O 2 -lean air from an oxygen-extraction process.   
     
     
         5 . The method according to  claim 1 , further comprising:
 mixing the air of the air-fuel mixture of the at least one pilot burner arrangement with the oxygen resulting in an O 2 -enriched working fluid, and further   mixing the O 2 -enriched fluid with fuel resulting in the air-fuel mixture for operating the at least one pilot burner arrangement.   
     
     
         6 . The method according to  claim 1 , further comprising:
 determining a feeding pressure of the oxygen and/or determining a feeding pressure of the fuel and,   controlling a flame stability of a pilot flame of the at least one pilot burner arrangement due to the determined feeding pressure of the oxygen and/or the feeding pressure of the fuel.   
     
     
         7 . The method according to  claim 1 , further comprising:
 controlling a feeding of an oxygen flow by at least one valve.   
     
     
         8 . The method according to  claim 1 , further comprising:
 stopping a feeding of oxygen to the air of the air-fuel mixture of the at least one pilot burner arrangement and/or the fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or the air-fuel mixture of the at least one pilot burner arrangement in case an oxygen content above 18% oxygen is detected in the air feed to the at least one pilot burner arrangement.   
     
     
         9 . The method according to  claim 1 , further comprising:
 purging an oxygen feed line with a flow medium in case an oxygen content above 18% oxygen is detected in the air feed to the at least one pilot burner arrangement.   
     
     
         10 . A combustion system of a combustion section of a gas turbine engine comprising:
 at least one main burner arrangement and at least one pilot burner arrangement, wherein the at least one main burner arrangement and the at least one pilot burner arrangement are operateable with an air-fuel mixture,   wherein the air for operating the at least one main burner arrangement is O 2 -lean air, and   at least one mixing device adapted to enrich oxygen in an air of the air-fuel mixture of the at least one pilot burner arrangement and/or in a fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or in the air-fuel mixture of the at least one pilot burner arrangement by mixing the air of the air-fuel mixture of the at least one pilot burner arrangement and/or the fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or the air-fuel mixture of the at least one pilot burner arrangement with oxygen.   
     
     
         11 . The combustion system according to  claim 10 , further comprising:
 at least one oxygen feed line at least one air feed line and/or at least one O 2 -enriched working fluid feed line and/or at least one fuel feed line,   wherein an at least first mixing device is positioned to be feed with oxygen by the at least one oxygen feed line and with air by the at least one air feed line and/or wherein an at least second mixing device is positioned to be feed with the O 2 -enriched working fluid by the at least one O 2 -enriched working fluid feed line and with fuel by the at least one air feed line.   
     
     
         12 . The combustion system according to  claim 10 , further comprising:
 at least one valve to control a feed of oxygen to the at least one feed line for the oxygen.   
     
     
         13 . The combustion system according to  claim 10 , adapted for operating a method comprising:
 operating the at least one main burner arrangement with O 2 -lean air, and   enriching an air of the air-fuel mixture of the at least one pilot burner arrangement and/or a fuel of the air-fuel mixture of the at least one pilot burner arrangement and/or the air-fuel mixture of the at least one pilot burner arrangement with oxygen.   
     
     
         14 . A gas turbine engine comprising:
 at least one combustion system according to  claim 10 .   
     
     
         15 . The method according to  claim 1 ,
 wherein the air is enriched with pure oxygen.   
     
     
         16 . The combustion system according to  claim 10 , wherein the oxygen in the air of the air-fuel mixture is pure oxygen.