Patent Application
20140345287
The subject matter disclosed herein relates generally to gas turbine systems, and more particularly, to a system and method for reducing resonant behavior associated with combustion dynamics in adjacent combustors of the gas turbine system.
Gas turbine systems generally include at least one gas turbine engine having a compressor section, a combustor section, and a turbine section. The combustor section may have one or more combustors (e.g., combustion cans) with fuel nozzles, which help to inject and mix a fuel and air in each combustor. Each combustor has a chamber to combust a mixture of the fuel and air, thereby generating hot combustion gases that drive one or more turbine stages in the turbine section. In each combustor, the relationship between an unsteady flame and system acoustics can create a variety of combustion dynamics, which generally involve dynamic pressure variations in the hot gas path (e.g., including the chamber of the combustor and through stages of the turbine section). As discussed below, it is desirable to minimize dynamic pressure variations in the hot gas path and avoid resonant behavior in the gas turbine system, thereby minimizing vibration and stress and extending the life of the gas turbine system.
Certain embodiments commensurate in scope with the originally claimed invention are summarized below. These embodiments are not intended to limit the scope of the claimed invention, but rather these embodiments are intended only to provide a brief summary of possible forms of the invention. Indeed, the invention may encompass a variety of forms that may be similar to or different from the embodiments set forth below.
In a first embodiment, a system includes a first combustor having a first combustion chamber, a first head end with a first plurality of fuel nozzles, and a first effusion plate. The first effusion plate is disposed between the first combustion chamber and the first head end chamber. The first effusion plate has a first plurality of openings for the first plurality of fuel nozzles, and the first effusion plate has a first plurality of openings configured to enable air flow into the first combustion chamber. The system includes a second combustor having a second combustion chamber, a second head end with a second plurality of fuel nozzles, and a second effusion plate. The second effusion plate disposed between the second combustion chamber and the second head end chamber, and has a second plurality of openings for the second plurality of fuel nozzles. The second effusion plate comprises a second plurality of air ports configured to enable air flow into the second combustion chamber, such that the first plurality of air ports in the first effusion plate have differences relative to the second plurality of air ports in the second effusion plate.
In a second embodiment, a system includes a first effusion plate having a first plurality of openings for a first plurality of fuel nozzles. The first effusion plate is configured to mount between a first head end chamber and a first combustion chamber of a first gas turbine combustor. The first effusion plate includes a plurality of first sectors. Each first sector has one of the first plurality of openings for one of the first plurality of fuel nozzles, and each first sector comprises a first plurality of air ports configured to direct a first air flow from the first head end chamber into the first combustion chamber. In addition, at least two first sectors of the plurality of first sectors comprise first differences between the respective first plurality of air ports.
In a third embodiment, a method includes routing a first air flow through a first effusion plate from a first head end chamber to a first combustor. The first head end chamber has a first plurality of fuel nozzles, and the first effusion plate is disposed between the first combustion chamber and the first head end chamber. The first effusion plate has a first plurality of openings for the first plurality of fuel nozzles, and the first effusion plate comprises a first plurality of air ports configured to enable the first air flow into the first combustion chamber. The method also includes routing a second air flow through a second effusion plate from a second head end chamber to a second combustor. The second head end chamber has a second plurality of fuel nozzles, and the second effusion plate is disposed between the second combustion chamber and the second head end chamber. The second effusion plate has a second plurality of openings for the second plurality of fuel nozzles, and the second effusion plate comprises a second plurality of air ports configured to enable the second air flow into the second combustion chamber. The method also includes reducing a possibility of resonant behavior via differences in the first plurality of air ports in the first effusion plate relative to the second plurality of air ports in the second effusion plate.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments of the present invention, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
As discussed in detail below, the disclosed embodiments are directed toward reducing pressure fluctuations and/or avoiding resonant behavior using one or more patterns of holes associated with one or more effusion plate within a gas turbine system. For example, an effusion hole pattern may vary from one effusion plate to another, and thus from one combustor to another. By further example, an effusion hole pattern may vary from one portion (e.g., sector) to another on each effusion plate in each combustor, while also varying from one combustor to another. Each different effusion plate (or hole pattern) may help to change an acoustic response of the combustor. Therefore, the variable hole patterns help to avoid the development of resonant behavior associated with the combustion dynamics (e.g., pressure fluctuations or pulsations) occurring from one combustor to another, and also within each combustor. As appreciated, if the frequency of the combustion dynamics (e.g., pressure fluctuations or pulsations) approaches or matches the natural frequency of the components in the hot gas path, then the components may exhibit resonant behavior that can cause increasing vibration, increasing stress, and potential damage to the components. The components may include components of the combustors (e.g., fuel nozzles, combustor liner, combustor transition piece, turbine blades, turbine shrouds, turbine nozzles, turbine seals, turbine bearings, exhaust conduits, sensors, and so forth). Accordingly, the disclosed embodiments employ variable hole patterns in the effusion plates in the combustors to help vary the frequency of the pressure pulsations (e.g., combustion dynamics) from one combustor to another, and also within each combustor in certain embodiments. In this manner, the variability in the combustion dynamics helps break up any coherence among combustors, thereby reducing the possibility of resonant behavior. For example, the variable effusion plates (e.g., variable hole patterns) help to break up any in-phase and coherence relationship between adjacent combustors of the gas turbine system by introducing a phase difference between the acoustic responses of adjacent combustors. More specifically, each effusion plate is configured to control an inlet boundary condition (e.g., concentration and/or distribution of air within the air-fuel mixture leading into the combustion chamber) of each combustor, so that the inlet boundary conditions of adjacent combustors are different. Modifying the inlet boundary condition for each combustor may generate differences (e.g., phase differences) among the acoustic responses of all the combustors within the gas turbine system.
As discussed in further detail below, the disclosed embodiments are directed towards a plurality of modified effusion plates within the gas turbine system having a plurality of air ports (e.g., effusion cooling ports) with different hole patterns. Although the present discussion refers to air as an oxidant and/or coolant, the disclosed embodiments are not limited to air as the oxidant and/or coolant, and thus the disclosed embodiments are equally applicable to oxygen, air, oxygen-enriched air, oxygen-reduced air, or any combination thereof. In certain embodiments, the effusion plate is modified by changing various physical characteristics of the air ports, such as, for example, the distance between the air ports, the pattern or arrangement of the air ports, the size of the air ports, the shape of the air ports, the locations of the air ports, or a combination thereof. In some embodiments, the effusion plate has one or more sectors, and is modified by changing various physical characteristics (e.g., the distance between the air ports, the pattern or arrangement of the air ports, the size of the air ports, the shape of the air ports, the locations of the air ports, or a combination thereof) of air ports from one sector to another. Changing physical properties of the air ports modifies the inlet boundary condition for each combustor, and in turn introduces a phase difference between the acoustic responses of adjacent combustors. In particular, the physical characteristics of the air ports on the modified effusion plate may be changed for alternate combustors, such that adjacent combustors do not have similar acoustic responses to the inlet boundary conditions.
With the forgoing in mind,
The turbine combustors 14 ignite and combust the pressurized air and fuel mixture (e.g., an air-fuel mixture) within the combustion chambers 19, and then pass resulting hot pressurized combustion gases 24 (e.g., exhaust) into the turbine 16. Turbine blades within the turbine 16 are coupled to a shaft 26 of the gas turbine system 10, which may also be coupled to several other components throughout the turbine system 10. As the combustion gases 24 flow against and between the turbine blades of the turbine 16, the turbine 16 is driven into rotation, which causes the shaft 26 to rotate. Eventually, the combustion gases 24 exit the turbine system 10 via an exhaust outlet 28. Further, in the illustrated embodiment, the shaft 26 is coupled to a load 30, which is powered via the rotation of the shaft 26. The load 30 may be any suitable device that generates power via the torque of the turbine system 10, such as an electrical generator, a propeller of an airplane, or other load.
The compressor 12 of the gas turbine system 10 includes compressor blades. The compressor blades within the compressor 12 are coupled to the shaft 26, and will rotate as the shaft 26 is driven to rotate by the turbine 16, as discussed above. As the compressor blades rotate within the compressor 12, the compressor 12 compresses air (or any suitable oxidant) received from an air intake 32 to produce pressurized air 34. The pressurized air 34 is then fed into the fuel nozzles 18 of the combustors 14. As mentioned above, the fuel nozzles 18 mix the pressurized air 34 and fuel to produce a suitable mixture ratio for combustion, e.g., a combustion that causes the fuel to more completely burn, so as not to waste fuel or cause excess emissions. In the following discussion, reference may be made to an axial direction or axis 42 (e.g., a longitudinal axis) of the combustor 14, a radial direction or axis 44 of the combustor 14, and a circumferential direction or axis 46 of the combustor 14.
In the illustrated embodiment, one or more fuel nozzles 18 are attached to head end 52, and pass through the combustor cap assembly 54 to the combustion chamber 19. For example, the combustor cap assembly 54 receives one or more fuel nozzles 18 and may provide support for each fuel nozzle 18. The combustor cap assembly 54 is disposed on a downstream end of the fuel nozzles 18, thereby separating the fuel nozzles 18 from the combustion chamber of the combustion chamber 19 within the turbine combustor 14. In the illustrated embodiment, the fuel nozzles 18 include six fuel nozzles. More specifically, the fuel nozzles 18 includes a central fuel nozzle and five peripheral fuel nozzles disposed about the central fuel nozzle. However, in other embodiments, each combustor 14 may include other numbers of fuel nozzles 19 (e.g., 1 to 10 or more), with peripheral fuel nozzles surrounding a central fuel nozzle or without any central fuel nozzle. Moreover, each fuel nozzle 18 leads to the combustion chamber 19 through the effusion plate 11.
Each fuel nozzle 18 facilitates the mixing of pressurized air and fuel and directs the mixture through the combustor cap assembly 54 into the combustion chamber 19. The air fuel mixture may then combust in a primary combustion zone 62 of the chamber 19, thereby creating hot pressurized exhaust gases. These pressurized exhaust gases drive the rotation of blades within turbine 16. Each combustor 14 includes an outer wall (e.g., flow sleeve 58) disposed circumferentially about an inner wall (e.g., combustor liner 60) to define an intermediate flow passage or space 64, while the combustor liner 60 extends circumferentially about the combustion chamber 19. The inner and/or outer walls also may include a transition piece 66, which generally converges toward a first stage of the turbine 16. The liner 60 defines an inner surface of the combustor 14, directly facing and exposed to the combustion chamber 19. The flow sleeve 58 includes a plurality of perforations 61, which direct an airflow 67 from a compressor discharger 68 into the flow passage 64 while also impinging air against the liner 60 and the transition piece 66 for purposes of impingement cooling. The flow passage 64 then directs the airflow 67 in an upstream direction toward the head end 50 (e.g., relative to a downstream direction 69 of the hot combustion gases), such that the airflow 67 further cools the liner 60 before flowing through the head end chamber 51, through the fuel nozzles 18, and through the effusion plate 11 of the combustor cap assembly 54 into the combustion chamber 19.
In particular, the effusion plate 11 of the combustor cap assembly 54 may define an outer face 72 (e.g., downstream face or hot face) of the combustor cap assembly 54. The effusion plate 11 is positioned at an upstream end of the combustion chamber 19 and at a downstream end of the fuel nozzles 18, i.e., relative to the downstream direction 69 of the hot combustion gases. The effusion plate 11 of the combustor cap assembly 54 may, for example, be circular in shape and may allow one or more fuel nozzles 18 to pass through annular openings (e.g., fuel nozzle ports 74. The effusion plate 11 has the effusion hole pattern 13 of air ports 76 (e.g., 10 to 1000 air ports) dispersed through the effusion plate 11 on the outer face 72. In certain embodiments, the effusion hole pattern 13 is formed in the spaces around the fuel nozzle ports on the effusion plate 11. In certain embodiments, the effusion plate 11 may be a single plate or one-piece structure without any breaks or barriers between fuel nozzle ports and associated fuel nozzles 18. Again, each effusion plate 11 may have a different effusion hole pattern 13 (e.g., arrangement, sizing, spacing, locations, etc.) of air ports 76, thereby helping to vary the inlet boundary conditions in each combustor 14 to avoid any resonant behavior associated with combustion dynamics among the plurality of combustors 14.
In other embodiments, the effusion plate 11 includes a plurality of sectors having a “pie-shaped” or “wedge-shaped” configuration. In such embodiments, a different effusion hole pattern 13 may be formed on each sector of the effusion plate 11. For example, the effusion plate 11 may include five peripheral sectors with fuel nozzles 18 arranged circumferentially about a central fuel nozzle, wherein the effusion hole patterns 13 alternate or otherwise vary from one sector to another. By further example, the effusion plate 11 may include other numbers of sectors (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10 or more), wherein the effusion hole patterns 13 alternate or otherwise vary from one sector to another. Again, each sector of the effusion plate 11 may include one or more fuel nozzles 18, and each effusion hole pattern 13 may include air holes with different sizing, spacing, locations, arrangements, shapes, or any combination thereof.
As described above, each fuel nozzle 18 directs the mixture of pressurized air and fuel through the effusion plate 11 and into the combustion chamber 19 of the combustor 14. In particular, the effusion plate 11 may include a plurality of air ports 76 (e.g., effusion cooling ports) defining the effusion hole pattern 13, as further discussed below with reference to the embodiments of
In particular, each combustor 14 may be similar in geometry and construction, but with differences in the effusion plate 11 among at least some of the combustors 14. For example, in certain embodiments, the geometry of the combustion chamber 19 within a first combustor 70 may be similar to the geometry of the combustion chamber 19 within a second combustor 71. Indeed, without the disclosed variances in effusion plates 11, the inlet boundary conditions for combustion chambers 19 with similar geometry (e.g., concentration of air within the air-fuel mixture leading to the combustion chambers 19) may be the same, leading to a similar acoustic response and strong in-phase coherence between the first and second combustors 70 and 71. However, in the disclosed embodiments, certain combustors 14 within the gas turbine system 10 include a modified effusion plate 11 configured to modify the acoustic response of the combustor 14 within the gas turbine system 10. The modified effusion plate 11 breaks the strong in-phase and coherence relationship between adjacent combustors 14 by introducing a phase difference between the acoustic responses of different combustors 14. For example, the first and second combustors 70 and 71 may have different effusion plates 11 with different effusion hole patterns 13, thereby helping to break the strong in-phase and coherence relationship between the first combustor 70 and the second combustor 71. Likewise, the other combustors 14 may have different effusion plates 11 with different effusion hole patterns 13. In some embodiments, the system 10 may include 2, 3, 4, 5, 6, 7, 8, 9, 10, or more different effusion plates 11 with different effusion hole patters 13 in any alternating arrangement, random arrangement, or organized arrangement among the plurality of combustors 14.
Again, the differences in the effusion hole pattern 13 from one effusion plate 11 (and combustor 14) to another may include the size of the air ports 76 (e.g., diameter), the angle of the air ports 76 (e.g., 0 to 90 degrees), the shape of the air ports 76, the spacing between adjacent air ports 76, the location of the air ports 76, the number of the air ports 76 (e.g., 10 to 1000), the arrangement or geometrical pattern, or any combination thereof. For example, the diameter of the air ports 76 may range from 5 microns to 5 mm, 10 microns to 2.5 mm, 20 microns to 1000 microns, 30 to 500 microns, 40 to 250 microns, or 50 to 100 microns. The diameter of the air ports 76 also may include any number of sizes (e.g., 1 to 100 sizes) on each effusion plate 11 and/or from one effusion plate 11 to another. For example, each effusion plate may include different sizes of air ports 76. The angle of the air ports 76 also may include any number of angles (e.g., 1 to 100 angles) on each effusion plate 11 and/or from one effusion plate 11 to another. The angle of the air ports 76 may include angles of approximately 10, 20, 30, 40, 50, 60, 70, 80, or 90 degrees, or any combination thereof, relative to a plane of the effusion plate 11. The shape of the air ports 76 also may include any number of shapes (e.g., 1 to 100 shapes) on each effusion plate 11 and/or from one effusion plate 11 to another. The shape of the air ports 76 may includes shapes that are circular, oval, rectangular, square, triangular, hexagonal, X-shaped, V-shaped, or any combination thereof. The spacing between the air ports 76 also may include any number of spacings (e.g., 1 to 100 spacings) on each effusion plate 11 and/or from one effusion plate 11 to another. The spacings may vary between approximately 1 mm to 5 cm. The location of the air ports 76 also may include any number of locations (e.g., 1 to 100 radial locations and/or 1 to 100 circumferential locations) on each effusion plate 11 and/or from one effusion plate 11 to another. The number of the air ports 76 also may vary from one effusion plate 11 to another by approximately 1 to 5000, 10 to 2000, 20 to 1000, 30 to 500, 40 to 250, or 50 to 100 air ports 76. The geometrical pattern of the air ports 76 also may vary from one effusion plate 11 to another and/or each effusion plate 11 may have any number of geometrical patterns. The geometrical patterns may include radial 44 rows of air ports 76, circumferential 46 rows (e.g., ring-shaped arrangements) of air ports 76, staggered arrangements of air ports 76 in the radial 44 and/or circumferential 46 directions, random positioning of air ports 76, or any other geometrical arrangement of air ports 76 along the plane of each effusion plate 11. Thus, the geometrical patterns may include various random patterns (e.g., non-uniform patterns) and/or organized patterns (e.g., uniform patterns). Again, the term effusion hole pattern 13 is intended to cover all of the permutations discussed above and further below.
In the illustrated embodiment, the effusion plate 11 includes a plurality of air ports 76, such as, for example, approximately 100 to 5000 air ports 76. In one embodiment, there may be approximately 1000 air ports 76 in total through the effusion plate 11. Additionally, each air port 76 may have a diameter 79 between approximately 5 and 200 mils, 10 and 100 mils, or 20 and 40 mils. For example, each air port 76 may be at least less than about 20, 30, 40, 50, 60, 70, 80, 90, or 100 mils in diameter. Furthermore, the distance between the air ports 76 may be a first distance 96, and may be between approximately 10 and 400 mils, 20 and 200 mils, or 40 and 80 mils.
The air ports 76 may allow fluid (e.g., air flow) to pass through the effusion plate 11 to aid in the combustion process of the combustion chamber 19, while also providing effusion cooling of the plate 11. Thus, the air ports 76 may extend from a rear face 84 (e.g., upstream face) axially through the plate 11 to the outer face 72. Furthermore, the air ports 76 may be angled relative to the outer face 72 of the effusion plate 11. For example, the air ports 76 may pass fluid out of the air ports 76 at an angle of approximately 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, and/or 5 degrees relative to the outer face 72. In another embodiment, the air ports 76 may be positioned at an angle of approximately less than about 45 degrees relative to the outer face 72. Alternatively, each air port 76 may be positioned at an angle of between approximately 20 to 70 degrees relative to the outer face 72. Furthermore, the air ports 76 may be parallel or non-parallel, converging, or diverging. In one embodiment, the air ports 76 may converge towards the fuel nozzles 18.
In the illustrated embodiment, the modified effusion plate 11 includes a plurality of air ports 76, such as, for example, approximately 100 to 5000 air ports 76. In one embodiment, there may be approximately 1000 air ports 76 in total through the effusion plate 11. Additionally, each air port 76 may have a diameter 79 between approximately 5 and 200 mils, 10 and 100 mils, or 20 and 40 mils. In particular, the size (e.g., diameter 79) of the air ports 76 on the modified effusion plate 11 of
Furthermore, the distance between the air ports 76 may be a second distance 98, and may be between approximately 2 and 400 mils, 20 and 200 mils, or 40 and 80 mils. In the illustrated embodiment, the first distance 96 between air ports 76 of
As described above, the effusion plate 11 of the combustor cap assembly 54 may be annularly shaped and may enable one or more fuel nozzles 18 to pass through the fuel nozzle ports 74. In certain embodiments, each fuel nozzle port 74 is disposed on a different sector 77 radiating from a central fuel nozzle port 78, such that the fuel nozzle ports 74 are arranged circumferentially around an axis 42 (e.g., central axis) of the combustor 14. In particular, the air ports 76 disposed on a particular sector 77 may regulate an inlet boundary condition (e.g., concentration of air within the mixture of pressurized air and fuel) of the combustion chamber 19, and may thus have an effect on the combustion process that occurs within the combustion chamber 19. In particular, the air ports 76 disposed on a particular sector 77 are configured to influence the acoustic response of the combustion chamber 19, such that adjacent combustors 14 within the gas turbine system 10 have different acoustic responses. As such, the effusion plate 11 is configured to break resonant behavior between adjacent combustors 14 of the gas turbine system 10. In addition, the effusion plate 11 with one or more sectors 77 may be configured to break resonant behavior within a particular combustion chamber 19.
The effusion plate 11 may include a plurality of air ports 76 (e.g., effusion cooling ports) that enable a fluid (e.g., air) to come in contact with the mixture of pressurized air and fuel flowing through the fuel nozzles 18 as the fuel nozzles 18 pass through the effusion plate 11. In certain embodiments, the air ports 76 may influence the amount of air within the mixture of pressurized air and fuel delivered to the combustion chamber 19, thereby influencing the combustion dynamics and the amount of hot pressurized exhaust gases generated during combustion. As such, the air ports 76 may indirectly control an inlet boundary condition (e.g., air flow) to the combustion process occurring in the combustion chamber 19. Furthermore, modifying the effusion plate 11 of adjacent combustors 14 (e.g., adjacent combustion chambers 19) may indirectly modify the combustion process occurring in adjacent combustion chambers 19, e.g., via crossfire tubes extending between adjacent combustors 14.
As illustrated in
As described above, the air ports 76 may allow fluid (e.g., air flow) to pass through the sectors 77 to aid in the combustion process of the combustion chamber 19 corresponding to a particular sector 77. Thus, the air ports 76 may extend from the rear face 84 (e.g., upstream face) axially through the sectors 77, and out of the outer face 72 of the effusion plate 11. Furthermore, the air ports 76 may be angled relative to the outer face 72 of each of the sectors 77. For example, the air ports 76 may pass fluid out of the air ports 76 at an angle of approximately 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, and/or 5 degrees relative to the outer face 72. In another embodiment, the air ports 76 may be positioned at an angle of approximately less than about 45 degrees relative to the outer face 72. Alternatively, each air port 76 may be positioned at an angle of between approximately 20 to 70 degrees relative to the outer face 72. Furthermore, the air ports 76 may be parallel or non-parallel, converging, or diverging. In one embodiment, the air ports 76 may converge towards the fuel nozzles 18. In certain embodiments, the first sector 80 may pass fluid out of the air ports 76 at an angle different from the second sector 82. In yet other embodiments, the first sector 80 may have air ports 76 positioned in a different manner from the second sector 82.
As discussed further below, in certain embodiments, the physical characteristics of the air ports 76 may be changed to modify the effusion plate 11. In certain embodiments, the air ports 76 may be dispersed on the effusion plate 11 in a random pattern (e.g., non-uniform pattern) or in an organized pattern (e.g., uniform pattern). For example, in the illustrated embodiment of
As described above, the air ports 76 disposed the various sector 77s control the inlet boundary condition (e.g., air flow) to the combustion chamber 19, and as such, influence the acoustic response of the combustion chamber 19 to the combustion gases. The differences in air ports 76 (e.g., varying arrangement and/or sizes of air ports 76) between the first and second sectors 80 and 82 change the acoustic response of the combustion chamber 19, which collectively change the effusion hole pattern 13 for the particular combustor 14. As such, the air ports 76 on the effusion plate 11 (i.e., different than other effusion plates 11) help to avoid any resonant behavior between two adjacent combustors 14, while also helping to avoid any resonant behavior within the individual combustor 14.
In the illustrated embodiment, the modified effusion plate 11 depicts the first sector 80 and the second sector 82 having differently sized air ports 76. For example, the first sector 80 has a plurality of air ports 76 arranged concentrically around the fuel nozzle port 74 with a first diameter 92. In addition, the second sector 82 is adjacent to the first sector 80, and has a plurality of air ports 76 arranged concentrically around the fuel nozzle port 74 with a second diameter 94. In the illustrated embodiment, the second diameter is twice as large as the first diameter. For example, if the first diameter 92 is between approximately 5 and 200 mils, 10 and 100 mils, or 20 and 40 mils, then the second diameter 94 is between approximately 10 and 400 mils, 20 and 200 mils, or 40 and 80 mils. In other embodiments, the modified effusion plate 11 may be configured to have differently sized air ports 76 on each sector 77. In yet other embodiments, the differences in size between the air ports 76 may be three times greater, four times greater, five times greater, six times greater and so forth.
As described above, the differently sized air ports 76 disposed on the sectors 77 help to control the inlet boundary conditions (e.g., air flow) to the combustion chamber 19, and as such, influence the acoustic response of the combustion chamber 19 to the combustion gases. The differences in air ports 76 (e.g., varying size of air ports 76) between the first and second sectors 80 and 82 change the acoustic response of the combustion chamber 19. As such, the air ports 76 on the effusion plate 11 helps to avoid resonant behavior between two adjacent combustors 14, while also helping to avoid resonant behavior within the particular combustor 14.
In the illustrated embodiment, the modified effusion plate 11 depicts the first sector 80 and the second sector 82 having different distances between the air ports 76. For example, the first sector 80 has a plurality of air ports 76 arranged linearly radial from the central fuel nozzle port 78, such that the distance between the air ports 76 is a first distance 96. In addition, the second sector 82 is adjacent to the first sector 80, and has a plurality of air ports 76 arranged linearly radial from the central fuel nozzle port 78, such that the distance between the air ports 76 is a second distance 98. In the illustrated embodiment, the first distance 96 is twice as large as the second distance 98. For example, if the first distance 96 is between approximately 10 and 400 mils, 20 and 200 mils, or 400 and 80 mils, then the second distance 98 is between approximately 5 and 200 mils, 10 and 100 mils, or 20 and 40 mils. In other embodiments, the modified effusion plate 11 may be configured to have random distances between the air ports 76 on each sector 77. In yet other embodiments, the differences in distance between the air ports 76 may be three times greater, four times greater, five times greater, six times greater and so forth.
As described above, the air ports 76 disposed on the various sectors 77 help to control the inlet boundary conditions (e.g., air flow) to the combustion chamber 19, and as such, influence the acoustic response of the combustion chamber 19 to the combustion gases. The differences in air ports 76 (e.g., varying distance between the air ports 76) between the first and second sectors 80 and 82 change the acoustic response of the combustion chamber 19. As such, the air ports 76 on the effusion plate 11 help to avoid any resonant behavior between two adjacent combustors 14, while also helping to avoid any resonant behavior within the particular combustor 14.
In the illustrated embodiment, the modified effusion plate 11 depicts the first sector 80 and the second sector 82 having air ports 76 with a different arrangement and a different size. For example, the first sector 80 includes a plurality of air ports 76 having a first diameter 92 and being arranged linearly radial from the central fuel nozzle port 78 (e.g., radial row arrangement). In addition, the second sector 82 includes a plurality of air ports 76 having a second diameter 94 and being arranged concentrically around the fuel nozzle ports 74 (e.g., ring shaped arrangement). In other embodiments, the modified effusion plate 11 may be modified with different combinations of variables (e.g., size and distance, size and arrangement, distance and arrangement, distance and size and arrangement, and so forth).
Technical effects of the disclosed embodiments include a system and method for a modified effusion plate 11 within a gas turbine system 10. The effusion plate 11 is configured to modify the acoustic response of each combustion chamber 19 within the gas turbine 10 by breaking the strong in-phase and coherence relationship between adjacent combustors 14. More specifically, the effusion plate 11 is modified by changing various physical characteristics of the air ports 76, such as, for example, the distance between the air ports 76, the geometrical pattern or arrangement of the air ports 76, the size of the air ports 76, or a combination thereof. In such embodiments, changing physical properties of the air ports 76 modifies the inlet boundary condition for each combustion chamber 19, and in turn introduces a phase difference between the acoustic responses of adjacent combustors 14. In some embodiments using sectors 77 for the effusion plate 11, the physical characteristics of the air ports 76 may be changed for alternate sectors 77, such that adjacent combustors 14 do not have similar acoustic responses to the inlet boundary conditions.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
