Gas turbine combustor with multiple fuel stages and method of operation
A combustor for a gas turbine engine comprises: a head end section defining a head end plenum and containing a fuel nozzle assembly; and a liner extending downstream from the head end section to an aft frame and defining a combustion chamber therein. First injectors, disposed at a first axial location, direct a first fuel/air mixture through the liner. Second injectors, disposed at a different, second axial location, direct a second fuel/air mixture through the liner. Each of the head end section, the first injectors, and the second injectors receives a respective air supply from a compressor discharge plenum that at least partially surrounds the combustor. The respective air supplies are directed to only one of the fuel nozzle assembly, the first injectors, and the second injectors. The first injectors and the second injectors receive more than 50% of the air supply from the compressor discharge plenum.
1 . A combustor for a gas turbine engine, the combustor defining a combustor centerline, the combustor comprising:
a head end section defining a head end air plenum and containing a fuel nozzle assembly;
a liner extending downstream from the head end section to an aft frame and defining a combustion chamber therein;
a first plurality of injectors disposed at a first axial location spaced apart from the head end section to direct a first fuel/air mixture through the liner, wherein at least one injector of the first plurality of injectors defines a first geometric stadium shape having first rounded ends, wherein the at least one injector of the first plurality of injectors is elongated along a first injector centerline that extends between the first rounded ends of the first geometric stadium shape, and wherein the first injector centerline is oriented at a first acute angle relative to the combustor centerline;
a second plurality of injectors disposed at a second axial location different from the first plurality of injectors to direct a second fuel/air mixture through the liner, wherein at least one injector of the second plurality of injectors defines a second geometric stadium shape having second rounded ends, wherein the at least one injector of the second plurality of injectors is elongated along a second injector centerline that extends between the second rounded ends of the second geometric stadium shape, wherein the second injector centerline is oriented at a second acute angle relative to the combustor centerline, and wherein the first acute angle is different than the second acute angle;
wherein each of the first plurality of injectors, and the second plurality of injectors, and the head end section receives each of a first, a second, and a third air supply, respectively, from a compressor discharge plenum that is defined by a compressor discharge casing that at least partially surrounds the combustor, each of the first, second, and third air supply being directed to only one of the first plurality of injectors, the second plurality of injectors, and the fuel nozzle assembly, respectively; and
wherein the first plurality of injectors and the second plurality of injectors receive more than 50% of a total of the first, second, and third air supply from the compressor discharge plenum.
2 . The combustor of claim 1 , wherein the first air supply to the first plurality of injectors is different in volume from both the second air supply to the second plurality of injectors and the third air supply to the head end section.
3 . The combustor of claim 1 , wherein an upstream portion of the liner is defined between the head end section and the first plurality of injectors, and a downstream portion of the liner is defined between the first plurality of injectors and the aft frame; and wherein the second plurality of injectors is disposed on the downstream portion of the liner.
4 . The combustor of claim 3 , wherein the second air supply to the second plurality of injectors is greater than each of the first air supply to the first plurality of injectors and the third air supply to the head end section.
5 . The combustor of claim 3 , wherein the second air supply to the second plurality of injectors is less than the sum of the first air supply to the first plurality of injectors and the third air supply to the head end section.
6 . The combustor of claim 1 , wherein the first plurality of injectors is surrounded by a first impingement sleeve having a first plurality of impingement openings; and wherein the first air supply from the compressor discharge plenum is in fluid communication with the first plurality of injectors, via the first plurality of impingement openings, such that the first air supply experiences a first pressure drop from flowing through the first plurality of impingement openings.
7 . The combustor of claim 6 , wherein the second plurality of injectors is surrounded by a second impingement sleeve having a second plurality of impingement openings; and wherein the second air supply from the compressor discharge plenum is in fluid communication with the second plurality of injectors, via the second plurality of impingement openings, such that the second air supply experiences a second pressure drop from flowing through the second plurality of impingement openings, the second pressure drop being different from the first pressure drop.
8 . The combustor of claim 1 , wherein the first plurality of injectors comprises at least two injectors; and wherein the second plurality of injectors comprises more than two injectors.
9 . The combustor of claim 8 , wherein at least one injector of the first plurality of injectors is disposed on a radially outer section of the liner, and at least one injector of the first plurality of injectors is disposed on a radially inner section of the liner; wherein the radially outer section of the liner is distal to an axial centerline of the gas turbine engine, and the radially inner section of the liner is proximal to the axial centerline of the gas turbine engine.
10 . The combustor of claim 8 , wherein at least one injector of the second plurality of injectors is disposed on a radially outer section of the liner, and at least one injector of the second plurality of injectors is disposed on a radially inner section of the liner; wherein the radially outer section of the liner is distal to an axial centerline of the gas turbine engine, and the radially inner section of the liner is proximal to the axial centerline of the gas turbine engine.
11 . The combustor of claim 8 , wherein the first plurality of injectors is grouped into a first subset and a second subset, the first subset being coupled to a first fuel circuit and the second subset being coupled to a second fuel circuit.
12 . The combustor of claim 8 , wherein the second plurality of injectors is grouped into a third subset and a fourth subset, the third subset being coupled to a third fuel circuit and the fourth subset being coupled to a fourth fuel circuit.
13 . The combustor of claim 1 , wherein the fuel nozzle assembly is a bundled tube fuel nozzle assembly that comprises a forward plate facing the head end air plenum, an aft plate facing the combustion chamber, a plurality of premixing tubes extending from the forward plate to the aft plate, and a side wall extending circumferentially around the plurality of premixing tubes and extending axially from the forward plate to the aft plate, such that the forward plate, the aft plate, and the side wall define a fuel plenum; wherein the head end air plenum is in fluid communication with the combustion chamber, via the plurality of premixing tubes; wherein each premixing tube of the plurality of premixing tubes includes at least one fuel injection hole therethrough in fluid communication with the fuel plenum; and wherein the bundled tube fuel nozzle assembly spans an entire diameter of the head end section.
14 . The combustor of claim 13 , wherein at least one damper is disposed through the fuel plenum of the bundled tube fuel nozzle assembly and extends into the head end air plenum.
15 . The combustor of claim 13 , wherein at least one resonator is disposed entirely within the head end section apart from the bundled tube nozzle assembly, the at least one resonator having a body and a neck extending therefrom, the neck being in fluid communication with the head end air plenum partially defined by an inlet flow conditioner surrounding the head end section.
16 . The combustor of claim 13 , wherein the head end section including the bundled tube fuel nozzle assembly and an inlet flow conditioner surrounding the bundled tube fuel nozzle assembly are collectively removeable from the liner.
17 . The combustor of claim 1 , wherein the first angle is less than the second angle.
18 . The combustor of claim 1 , wherein at least two adjacent injectors in the second plurality of injectors are each elongated along a respective second injector centerline, and wherein the respective second injector centerlines of the two adjacent injectors in the second plurality of injectors are oriented at different angles relative to the combustion centerline such that the respective second injector centerlines of the two adjacent injectors in the second plurality of injectors are oriented towards one another.
19 . A gas turbine engine comprising:
a compressor section;
a turbine section; and
a combustion section downstream of the compressor section and upstream of the turbine section, the combustion section comprising one or more combustors, the one or more combustors each defining a combustor axial centerline, the one or more combustors each comprising:
a head end section defining a head end air plenum and containing a fuel nozzle assembly;
a liner extending downstream from the head end section to an aft frame and defining a combustion chamber therein;
a first plurality of injectors disposed at a first axial location spaced apart from the head end section to direct a first fuel/air mixture through the liner, wherein at least one injector of the first plurality of injectors defines a first geometric stadium shape having first rounded ends, wherein the at least one injector of the first plurality of injectors is elongated along a first injector centerline that extends between the first rounded ends of the first geometric stadium shape, and wherein the first injector centerline is oriented at a first acute angle relative to the combustor centerline;
a second plurality of injectors disposed at a second axial location different from the first plurality of injectors to direct a second fuel/air mixture through the liner, wherein at least one injector of the second plurality of injectors defines a second geometric stadium shape having second rounded ends, wherein the at least one injector of the second plurality of injectors is elongated along a second injector centerline that extends between the second rounded ends of the second geometric stadium shape, wherein the second injector centerline is oriented at a second acute angle relative to the combustor centerline, and wherein the first acute angle is different than the second acute angle;
wherein each of the first plurality of injectors, the second plurality of injectors, and the head end section receives each of a first, second, and third air supply, respectively, from a compressor discharge plenum that is defined by a compressor discharge casing that at least partially surrounds the combustor, each of the first, second, and third air supply being directed to only one of the first plurality of injectors, and the second plurality of injectors, and the fuel nozzle assembly, respectively; and
wherein the first plurality of injectors and the second plurality of injectors receive more than 50% of a total of the first, second, and third air supply from the compressor discharge plenum.
20 . The combustor of claim 1 , wherein the first acute angle is about 10 degrees and the second acute angle is about 30 degrees.