Combustor and Gas Turbine

Abstract

A combustor according to at least one embodiment of the present disclosure is a combustor that causes compressed air supplied from a compressor to combust together with fuel. A combustor according to at least one embodiment of the present disclosure includes at least one fuel nozzle having a fuel flow path for supplying fuel and a purge air flow path for ejecting purge air. A combustor according to at least one embodiment of the present disclosure includes a nozzle-securing part for securing at least one fuel nozzle. A combustor according to at least one embodiment of the present disclosure includes a top hat body located on the outer peripheral side of at least part of the nozzle-securing part. The top hat body has a first internal flow path capable of supplying compressed air to the nozzle-securing part from a space on the outer peripheral side of the top hat body. The nozzle-securing part has a second internal flow path capable of supplying compressed air supplied from the first internal flow path to the purge air flow path of the fuel nozzle.

Description

Technical Field

[0001] The present disclosure relates to a combustor and a gas turbine. This application claims priority based on Japanese Patent Application No. 2022-007824 filed with the Japan Patent Office on January 21, 2022, the content of which is incorporated herein by reference.

Background Art

[0002] A combustor used in a gas turbine mainly includes a cylindrical body through which combustion gas flows, a plurality of nozzles that form flames inside the cylindrical body, and a plurality of swirling vanes provided around the nozzles. High-temperature and high-pressure combustion gas is generated inside the cylindrical body by the flames formed by the nozzles. By the way, inside the combustor, a phenomenon called flashback may occur in the process of fuel and air flowing. Flashback is a phenomenon in which abnormal combustion occurs due to the propagation of flames to an unexpected area inside the combustor. In particular, in the central region (vortex core) of the swirling flow formed by the above-mentioned swirling vanes, the flow velocity and pressure are lower than in other regions, so it is known that flashback is likely to occur. In order to avoid such flashback, for example, in the device described in Patent Document 1 below, by forming an air flow path that supplies air from the tip of the nozzle to the vortex core, the flow velocity of the fluid in the vortex core is increased. Air is introduced into the air flow path from a position upstream of the swirling vane (pressure loss part) in the nozzle. Thereby, it is said that flashback can be avoided.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses a configuration in which a part of the cabin air is taken into the fuel nozzle as purge air through piping outside the cabin. However, in the gas turbine combustor described in Patent Document 1, there is a problem that heat loss occurs because the cabin air passes through the piping outside the cabin.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a combustor and a gas turbine capable of suppressing heat loss in a gas turbine.

Means for Solving the Problems

[0006] (1) The combustor according to at least one embodiment of the present disclosure is a combustor that burns compressed air supplied from a compressor together with fuel, at least one fuel nozzle having a fuel flow path for supplying the fuel and a purge air flow path for ejecting purge air, a nozzle fixing portion for fixing the at least one fuel nozzle, a top hat body disposed on the outer peripheral side of at least a part of the nozzle fixing portion, and is provided with the top hat body has a first internal flow path capable of supplying the compressed air from the space on its outer peripheral side to the nozzle fixing portion, the nozzle fixing portion has a second internal flow path capable of supplying the compressed air supplied from the first internal flow path to the purge air flow path of the fuel nozzle.

[0007] (2) The gas turbine according to at least one embodiment of the present disclosure is the compressor, a combustor having the configuration of (1) above, a turbine configured to be driven by combustion gas from the combustor, and is provided with

Advantages of the Invention

[0008] According to at least one embodiment of the present disclosure, heat loss in a gas turbine can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0010] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure thereto, but are merely illustrative examples. For example, expressions representing relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial" not only strictly represent such arrangements, but also represent states of relative displacement with tolerances or angles and distances that can obtain the same function. For example, expressions indicating that things such as "identical", "equal", and "homogeneous" are in an equal state shall represent not only a strictly equal state, but also a state in which there are tolerances or differences to the extent that the same function can be obtained. For example, expressions representing shapes such as a rectangular shape or a cylindrical shape shall represent not only shapes such as a rectangular shape or a cylindrical shape in a geometrically strict sense, but also shapes including concave and convex portions, chamfered portions, etc. within the range where the same effect can be obtained. On the other hand, expressions such as "comprising", "possessing", "having", "including", or "owning" one component are not exclusive expressions excluding the existence of other components.

[0011] First, a gas turbine, which is an example of an application destination of a combustor according to some embodiments, will be described with reference to FIG. 1. FIG. 1 is a schematic configuration diagram of a gas turbine according to some embodiments. As shown in FIG. 1, the gas turbine 1 includes a compressor 2 for generating compressed air, a combustor 4 for generating combustion gas using the compressed air and fuel, and a turbine 6 configured to be rotationally driven by the combustion gas. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6.

[0012] The compressor 2 includes a plurality of stationary blades 16 fixed to the compressor casing 10 side and a plurality of rotating blades 18 implanted in the rotor 8 so as to be alternately arranged with respect to the stationary blades 16. Air taken in from the air intake 12 is sent to the compressor 2, and this air is compressed by passing through the plurality of stationary blades 16 and the plurality of rotating blades 18 to become high-temperature and high-pressure compressed air.

[0013] Fuel and the compressed air generated by the compressor 2 are supplied to the combustor 4, and in the combustor 4, the fuel is burned to generate combustion gas, which is the working fluid of the turbine 6. As shown in FIG. 1, the gas turbine 1 has a plurality of combustors 4 arranged circumferentially around the rotor 8 within the casing 20.

[0014] The turbine 6 has a combustion gas passage 28 formed by a turbine casing 22, and includes a plurality of stationary blades 24 and moving blades 26 provided in the combustion gas passage 28. The stationary blades 24 and moving blades 26 of the turbine 6 are provided on the downstream side of the combustor 4 with respect to the flow of combustion gas. The stationary blades 24 are fixed to the turbine casing 22 side, and a plurality of stationary blades 24 arranged along the circumferential direction of the rotor 8 constitute a stationary blade row. Further, the moving blades 26 are implanted in the rotor 8, and a plurality of moving blades 26 arranged along the circumferential direction of the rotor 8 constitute a moving blade row. The stationary blade row and the moving blade row are alternately arranged in the axial direction of the rotor 8. In the turbine 6, the combustion gas from the combustor 4 flowing into the combustion gas passage 28 passes through the plurality of stationary blades 24 and the plurality of moving blades 26, whereby the rotor 8 is rotationally driven around the axis O, and thereby, the generator connected to the rotor 8 is driven to generate electric power. The combustion gas after driving the turbine 6 is discharged to the outside through the exhaust chamber 30.

[0015] Next, the combustor 4 according to some embodiments will be described. FIG. 2 is a schematic view showing an inlet portion of the combustor 4 and the turbine 6 of the gas turbine 1 according to some embodiments. FIG. 3A is a schematic cross-sectional view of the combustor 4 of the gas turbine 1 according to one embodiment. FIG. 3B is a schematic cross-sectional view of the combustor 4 of the gas turbine 1 according to one embodiment, and represents a cross-section having a different position in the circumferential direction of the combustor (hereinafter, also simply referred to as the "circumferential direction") from that of FIG. 3A. FIG. 4 is a schematic cross-sectional view of a main part of the combustor 4 of the gas turbine 1 according to one embodiment. FIG. 5 is a schematic cross-sectional view taken along the line C-C of FIG. 4. FIG. 6 is a schematic cross-sectional view of the combustor 4 of the gas turbine 1 according to another embodiment. FIG. 7 is a schematic cross-sectional view of a main part of the combustor 4 of the gas turbine 1 according to another embodiment. FIG. 8 is a schematic cross-sectional view taken along the line F-F of FIG. 7.

[0016] As shown in FIGS. 2, 3A, 3B, and 6, in the gas turbine 1 according to some embodiments, each of a plurality of combustors 4 (see FIG. 1) arranged circumferentially around the rotor 8 is provided in a combustor compartment 32 defined by a casing 20, and includes a combustion cylinder (combustor liner) 36, a first combustion burner 38 disposed in the combustion cylinder 36, and a plurality of second combustion burners 44 disposed so as to surround the first combustion burner 38. That is, the combustion cylinder 36, the first combustion burner 38, and the second combustion burners 44 are housed in the casing 20.

[0017] The combustion cylinder (combustor liner) 36 has an inner cylinder 48 disposed around the first combustion burner 38 and the plurality of second combustion burners 44, and a tail cylinder 50 connected to the tip of the inner cylinder 48. Note that the inner cylinder 48 and the tail cylinder 50 may be integrally formed.

[0018] The first combustion burner 38 is arranged along the direction of the central axis C1 of the combustion cylinder 36 (that is, the axial direction of the combustor 4; hereinafter, also simply referred to as the "axial direction"), and has a first fuel nozzle 40 for injecting fuel and a first burner cylinder 41 disposed so as to surround the first fuel nozzle 40. Fuel is supplied to the first fuel nozzle 40 via a first fuel port 42.

[0019] The second combustion burner 44 has a second fuel nozzle 46 for injecting fuel and a second burner cylinder 47 disposed so as to surround the second fuel nozzle 46. Fuel is supplied to the second fuel nozzle 46 via a second fuel port 43.

[0020] The combustor 4 according to some embodiments includes a nozzle fixing portion 400. The first fuel nozzle 40 and the second fuel nozzle 46 are fixed to the nozzle fixing portion 400 at the base ends of the first fuel nozzle 40 and the second fuel nozzle 46.

[0021] The combustor 4 further includes an outer cylinder 52 provided on the outer peripheral side of the inner cylinder 48 inside the casing 20. An air passage 54 through which compressed air flows is formed on the outer peripheral side of the inner cylinder 48 and the inner peripheral side of the outer cylinder 52.

[0022] The compressed air generated by the compressor 2 (see FIG. 1) is supplied into the combustor chamber 32 through the vehicle compartment inlet 31. The compressed air flows from the combustor chamber 32 into the air passage 54 as combustion air, is deflected by a wall surface portion 53 provided along a plane perpendicular to the axial direction of the combustor 4, and flows into the first burner cylinder 41 and the second burner cylinder 47. In each burner cylinder, the fuel injected from the fuel nozzle is mixed with the compressed air (combustion air), and this mixture flows into the combustion cylinder 36, is ignited, and burns, thereby generating combustion gas.

[0023] The above-described first combustion burner 38 may be a burner for generating a diffusion combustion flame, and the second combustion burner 44 may be a burner for burning a premixed gas and generating a premixed combustion flame. That is, in the second combustion burner 44, the fuel from the second fuel port 43 and the compressed air are premixed, and the premixed gas mainly forms a swirling flow by the swirler 49 and flows into the combustion cylinder 36. Further, the compressed air and the fuel injected from the first combustion burner 38 through the first fuel port 42 are mixed in the combustion cylinder 36, are ignited by an ignition means (not shown), and burn to generate combustion gas. At this time, a part of the combustion gas diffuses around with a flame, so that the premixed gas flowing into the combustion cylinder 36 from each second combustion burner 44 is ignited and burns. That is, a flame holding for stably burning the premixed gas (premixed fuel) from the second combustion burner 44 can be performed by the diffusion combustion flame of the fuel injected from the first combustion burner 38.

[0024] In this way, the combustion gas generated by the combustion of the fuel in the combustor 4 flows into the turbine 6 through the outlet portion 51 of the combustor 4 located at the downstream end of the tail pipe 50.

[0025] The combustor 4 is provided with a third fuel nozzle 70 for injecting fuel into the above-described air passage 54. Note that a plurality of third fuel nozzles 70 may be provided along the circumferential direction. The third fuel nozzle 70 is fixed to a top hat body 60 described later. When fuel is injected from the third fuel nozzle 70 into the air passage 54, the compressed air flowing into the air passage 54 and the injected fuel are mixed, and this fuel-air mixture flows into each burner cylinder. Then, by injecting fuel from the first fuel nozzle 40 and the second fuel nozzle 46 as described above to form a mixture with respect to this fuel-air mixture, a uniform fuel-air mixture can be formed to achieve low NOx.

[0026] Note that the combustor 4 may be provided with other components such as a bypass pipe (not shown) for bypassing combustion gas.

[0027] In the combustor 4 according to some embodiments, a straightening plate 55 is disposed in the above-described air passage 54. The straightening plate 55 is a perforated plate provided between the inner cylinder 48 and the outer cylinder 52 and fixedly disposed on the outer peripheral portion of the inner cylinder 48, and a plurality of through holes penetrating the straightening plate 55 are disposed. The straightening plate 55 straightens the flow of the compressed air and causes a pressure loss when passing through the straightening plate 55. That is, in the air passage 54 through which the compressed air flows after passing through the straightening plate 55, the pressure is lower than that in the combustor chamber 32 (see FIG. 2) and the space 33 described later.

[0028] Hereinafter, the combustor 4 according to some embodiments will be described in more detail.

[0029] (Top hat body 60) As shown in FIGS. 3A, 3B, 4, 6, and 7, the combustor 4 according to some embodiments includes a flange portion 62 attached to the casing 20, an annular extension portion 64 extending axially along the combustor 4 from the flange portion 62, and a pipe portion 80 extending between the flange portion 62 and the extension portion 64. And the fuel from the third fuel port 74 is supplied to the third fuel nozzle 70 through the pipe portion 80 and a passage 65 (to be described later) formed inside the extension portion 64. The third fuel nozzle 70 is provided on the inner peripheral side of the extension portion 64. In the combustor 4 according to some embodiments, the portion composed of the flange portion 62 and the extension portion 64 may be called a top hat body 60 from its shape. The top hat body 60 according to some embodiments is a bottomed cylindrical member provided so as to close the combustor insertion hole 20h formed in the casing 20.

[0030] As shown in FIGS. 3A, 3B, 4, 6, and 7, the flange portion 62 has a shape protruding toward the outer side in the radial direction (hereinafter, also simply referred to as the "radial direction") of the combustor 4, and is fixed to the casing 20 by bolts 59.

[0031] The extension portion 64 has a cylindrical shape extending axially along the combustor 4 from the flange portion 62 toward the internal space of the casing 20. In some embodiments, the extension portion 64 is located radially inward of the casing 20. Further, the extension portion 64 has an annular protrusion 63 protruding radially inward. The wall surface portion 53 that changes the direction of the compressed air flow flowing through the air passage 54 described above is formed by the annular protrusion 63.

[0032] As shown in FIGS. 3A, 3B, 4, 6, and 7, the air passage 54 may be at least partially formed by the extension portion 64. That is, the extension portion 64 may include an air passage forming portion 66 (outer cylinder 52) that forms the air passage 54.

[0033] As shown in FIGS. 3A and 3B, in the gas turbine 1 according to one embodiment, in the circumferential region of the outer cylinder 52, in the region located relatively radially outward about the axis O of the rotor 8, the outer peripheral surface 52a of the outer cylinder 52 is spaced apart from the inner peripheral surface 20i of the combustor insertion hole 20h. Thus, in the gas turbine 1 according to one embodiment, in the region located relatively radially outward about the axis O of the rotor 8, a cavity 33 through which compressed air can flow is formed between the outer peripheral surface 52a of the outer cylinder 52 and the inner peripheral surface 20i of the combustor insertion hole 20h.

[0034] As shown in FIG. 6, in the gas turbine 1 according to another embodiment, the outer peripheral surface 52a of the outer cylinder 52 is spaced apart from the inner peripheral surface 20i of the combustor insertion hole 20h over its entire circumference. Thus, in the gas turbine 1 according to another embodiment, a cavity 33 through which compressed air can flow is formed between the outer peripheral surface 52a of the outer cylinder 52 and the inner peripheral surface 20i of the combustor insertion hole 20h over the entire circumference of the outer peripheral surface 52a.

[0035] As shown in FIGS. 3A, 3B, 4, 6, and 7, inside the top hat body 60 according to some embodiments, a first internal flow path 61 capable of supplying compressed air from the space (cavity 33) on the outer peripheral side thereof to the nozzle fixing portion 400 is formed. The first internal flow path 61 according to some embodiments has a first inlet 61a which is an inlet of the first internal flow path 61, and a first outlet 61b which is an outlet located radially inward of the combustor 4 relative to the first inlet 61a. In the first internal flow path 61 according to some embodiments, the first inlet 61a is formed on the outer peripheral surface 52a of the outer cylinder 52. In the first internal flow path 61 according to some embodiments, the first outlet 61b is formed on the inner peripheral portion 60a of the top hat body 60 facing the nozzle fixing portion 400, specifically, on the inner peripheral surface 63a of the annular protrusion 63 as well shown in FIGS. 4 and 7.

[0036] As shown in FIGS. 3A and 3B, in the combustor 4 according to one embodiment, there is no void 33 in the relatively radially inner side centered on the axis O of the rotor 8. The radially inner side centered on the axis O of the rotor 8 is the lower side shown in FIG. 5. Therefore, in the combustor 4 according to one embodiment, as shown in FIG. 5, the first internal flow path 61 is provided on the radially outer side centered on the axis O of the rotor 8, that is, the upper side shown in FIG. 5, but is not provided on the lower side shown in FIG. 5.

[0037] As shown in FIG. 6, in the combustor 4 according to another embodiment, there is also a void 33 in the relatively radially inner side centered on the axis O of the rotor 8. Therefore, in the combustor 4 according to another embodiment, as shown in FIG. 8, the first internal flow path 61 is provided not only on the upper side shown in FIG. 5 but also on the lower side shown in FIG. 5.

[0038] In some embodiments, at least a part of the first internal flow path 61 is formed inside the extension part 64. In the gas turbine 1 according to one embodiment shown in FIGS. 3A and 3B, for example, as shown in FIG. 5, at least one, preferably a plurality of first internal flow paths 61 may be provided. In the gas turbine 1 according to another embodiment shown in FIG. 6, the first internal flow path 61 may be provided for each of the plurality of second internal flow paths 402 described later, for example, as shown in FIGS. 7 and 8.

[0039] Inside the extension part 64, a passage 65 for passing fuel is provided. The passage 65 includes an annular passage 67 formed along the circumferential direction of the combustor 4, and a first connection passage 68 and a second connection passage 69 connected to the annular passage 67.

[0040] The first connection passage 68 is provided between the internal flow path of the pipe part 80 and the annular passage 67, and the internal flow path of the pipe part 80 and the annular passage 67 are communicated with each other through the first connection passage 68. The second connection passage 69 is provided between the annular passage 67 and the third fuel nozzle 70. In addition, when a plurality of third fuel nozzles 70 are provided in the combustor 4, a second connection passage 69 is provided for each of the plurality of third fuel nozzles 70. In the following description, the second connection passage 69 is also referred to as a third internal flow passage 69A.

[0041] The first internal flow passage 61 according to some embodiments may intersect the third internal flow passage 69A when viewed in the circumferential direction of the combustor 4. Therefore, for example, as shown in FIGS. 5 and 8, the first internal flow passage 61 is formed at a position different from the third internal flow passage 69A in the circumferential direction so as not to interfere with the third internal flow passage 69A. In addition, in FIGS. 5 and 8, the description of the fuel flow passage for supplying fuel to the first fuel nozzle 40 and the second fuel nozzle 46, and the first connection passage 68 is omitted.

[0042] (Nozzle fixing portion 400) As shown in FIGS. 3A, 3B, 4, 6, and 7, in the combustor 4 according to some embodiments, the nozzle fixing portion 400 includes, for example, a flange portion 410 attached to the annular protruding portion 63 of the top hat body 60, and a columnar main body portion 420 extending along the axial direction of the combustor 4 from the flange portion 410. The main body portion 420 is inserted into the inner peripheral surface 63a of the annular protruding portion 63 of the top hat body 60.

[0043] In the combustor 4 according to some embodiments, the nozzle fixing portion 400 has a second internal flow passage 402 capable of supplying the compressed air supplied from the first internal flow passage 61 to a purge air flow passage 461 (to be described later) of the second fuel nozzle 46. In the combustor 4 according to some embodiments, the second internal flow passage 402 is provided corresponding to each of the plurality of second fuel nozzles 46. The second internal flow passage 402 according to some embodiments has a second inlet 402a that is an inlet of the second internal flow passage 402, and a second outlet 402b that is an outlet connected to the purge air flow passage 461 of the second fuel nozzle 46. In the second internal flow path 402 according to some embodiments, the second inlet 402a is formed on the outer peripheral portion 400a of the nozzle fixing portion 400 facing the top hat body 60, specifically, on the outer peripheral surface 420a of the main body portion 420. In the second internal flow path 402 according to some embodiments, the second outlet 402b is connected to the inlet 461a of a purge air flow path 461, which will be described later, of the second fuel nozzle 46.

[0044] (Cavity) As shown in FIGS. 4 and 5, in a combustor 4 according to an embodiment, the top hat body 60 and the nozzle fixing portion 400 define a cavity 500 that extends circumferentially between the top hat body 60 and the nozzle fixing portion 400. More specifically, the cavity 500 is formed between the inner peripheral surface 63a of the annular protrusion 63 of the top hat body 60 and the outer peripheral surface 420a of the main body portion 420 of the nozzle fixing portion 400.

[0045] As shown in FIG. 4, in a combustor 4 according to an embodiment, the cavity 500 includes a downstream region 510 on the axially downstream side and an upstream region 520 on the axially upstream side. In the combustor 4 according to an embodiment, when viewed axially, the flow path cross-sectional area of the downstream region 510 is smaller than the flow path cross-sectional area of the upstream region 520. That is, in the combustor 4 according to an embodiment, the radial height of the cavity 500 is smaller in the downstream region 510 than in the upstream region 520.

[0046] In the combustor 4 according to an embodiment, the first internal flow path 61 is in fluid communication with the cavity 500. More specifically, in the combustor 4 according to an embodiment, the first outlet 61b of the first internal flow path 61 opens to the inner peripheral surface 63a of the annular protrusion 63 that defines the downstream region 510 of the cavity 500. In the combustor 4 according to one embodiment, the second internal flow path 402 is in fluid communication with the cavity 500. More specifically, in the combustor 4 according to one embodiment, the second inlet 402a of the second internal flow path 402 opens to the outer peripheral surface 420a of the main body portion 420 that defines the downstream region 510 of the cavity 500. That is, in the combustor 4 according to one embodiment, the first internal flow path 61 and the second internal flow path 402 are in fluid communication via the cavity 500.

[0047] As shown in FIG. 7, in the combustor 4 according to another embodiment, the cavity 500 may not be provided. In this case, in the combustor 4 according to another embodiment, the first outlet 61b of the first internal flow path 61 may be directly connected to the second inlet 402a of the second internal flow path 402.

[0048] (Second fuel nozzle 46) In the combustor 4 according to some embodiments, the second fuel nozzle 46 is substantially tubular, and a purge air flow path 461 and a fuel flow path 462 are formed therein. As shown in FIGS. 4 and 7, in the second fuel nozzle 46 according to some embodiments, the purge air flow path 461 extends along the central axis C2 of the second fuel nozzle 46 within the second fuel nozzle 46. The outlet 461b of the purge air flow path 461 is formed at the tip 46a of the second fuel nozzle 46. Note that the central axis C2 of the second fuel nozzle 46 is parallel to the central axis C1 of the combustion cylinder 36.

[0049] (Regarding injection of purge air) In the combustor 4 according to some embodiments configured as described above, during operation of the gas turbine 1, the compressed air generated by the compressor 2 (see FIG. 1) is supplied into the combustor chamber 32 through the chamber inlet 31 and is supplied to the first combustion burner 38 and the second combustion burner 44 as combustion air as described above. In the gas turbine 1 according to one embodiment shown in FIG. 4, the compressed air supplied into the combustor compartment 32 is supplied from the above-described cavity 33 to the cavity 500 through the first internal flow path 61. The compressed air supplied to the cavity 500 is distributed to each second internal flow path 402 and flows into the purge air flow path 461 of each second fuel nozzle 46. The compressed air that has flowed into the purge air flow path 461 is injected into the combustion cylinder 36 as purge air Pa from the outlet 461b of the purge air flow path 461 as shown by the arrow IV in FIG. 4.

[0050] In the gas turbine 1 according to another embodiment shown in FIG. 7, the compressed air supplied into the combustor compartment 32 flows from the above-described cavity 33 into the purge air flow path 461 of each second fuel nozzle 46 through each first internal flow path 61 and each second internal flow path 402. The compressed air that has flowed into the purge air flow path 461 is injected into the combustion cylinder 36 as purge air Pa from the outlet 461b of the purge air flow path 461 as shown by the arrow VII in FIG. 7.

[0051] (Regarding flashback) In the combustor 4 according to some embodiments, since the second combustion burner 44 is provided with a swirler 49, the premixed combustion flame generated by the second combustion burner 44 includes a swirling flow component. That is, this premixed combustion flame propagates while swirling around the second fuel nozzle 46 from one axial side of the combustor 4 to the other side. Therefore, a vortex core of the swirling flow is formed on the other axial side of the combustor 4 at the tip of the second fuel nozzle 46. It is known that flashback is likely to occur in the vortex core because the flow velocity and pressure are lower than in other regions. Flashback is a phenomenon in which an abnormal combustion occurs when a flame propagates to fuel staying in an unexpected region in the combustor 4.

[0052] In the combustor 4 according to some embodiments, as described above, since the purge air Pa is injected into the combustion cylinder 36 from the outlet 461b of the purge air flow path 461 formed at the tip 46a of the second fuel nozzle 46, the flow velocity and pressure of the fluid in the vortex core can be increased. Thereby, the above-described flashback can be suppressed.

[0053] The combustor 4 according to some embodiments is a combustor 4 that burns compressed air supplied from the compressor 2 together with fuel. The combustor 4 according to at least one embodiment of the present disclosure includes a second fuel nozzle 46 which is at least one fuel nozzle having a fuel flow path 462 for supplying fuel and a purge air flow path 461 for ejecting purge air Pa. The combustor 4 according to at least one embodiment of the present disclosure includes a nozzle fixing portion 400 for fixing the second fuel nozzle 46 which is at least one fuel nozzle. The combustor 4 according to at least one embodiment of the present disclosure includes a top hat body 60 disposed on the outer peripheral side of at least a part of the nozzle fixing portion 400. In the combustor 4 according to some embodiments, as described above, the top hat body 60 has a first internal flow path 61 capable of supplying compressed air from a cavity 33 which is a space on its outer peripheral side to the nozzle fixing portion 400. The nozzle fixing portion 400 has a second internal flow path 402 capable of supplying the compressed air supplied from the first internal flow path 61 to the purge air flow path 461 of the second fuel nozzle 46 which is a fuel nozzle.

[0054] Thereby, the compressed air with relatively little pressure loss supplied from the compressor 2 without passing through the rectifying plate 55 can be supplied as purge air Pa to the second fuel nozzle 46 which is a fuel nozzle. Further, in the combustor 4 according to some embodiments, the compressed air supplied as purge air Pa can be supplied to the purge air flow path 461 of the second fuel nozzle 46 which is a fuel nozzle without passing through a flow path via the outside of the combustor 4. Thereby, the compressed air can be supplied as purge air Pa to the second fuel nozzle 46 which is a fuel nozzle while suppressing heat loss. Therefore, in the gas turbine 1 including the combustor 4 according to some embodiments, heat loss can be suppressed.

[0055] The gas turbine 1 according to some embodiments includes a compressor 2, a combustor 4 according to some embodiments, and a turbine 6 configured to be driven by combustion gas from the combustor 4. Thereby, heat loss in the gas turbine 1 can be suppressed.

[0056] In the combustor 4 according to some embodiments, as described above, the first outlet 61b may be formed in the inner peripheral portion 60a of the top hat body 60 facing the nozzle fixing portion 400. Thereby, the formation location of the first outlet 61b is reasonable for fluidly communicating the first internal flow path 61 formed in the top hat body 60 and the second internal flow path 402 formed in the nozzle fixing portion 400.

[0057] In the combustor 4 according to some embodiments, as described above, the second inlet 402a may be formed in the outer peripheral portion 400a of the nozzle fixing portion 400 facing the top hat body 60. Thereby, the formation location of the second inlet 602a is reasonable for fluidly communicating the first internal flow path 61 formed in the top hat body 60 and the second internal flow path 402 formed in the nozzle fixing portion 400.

[0058] In the combustor 4 according to an embodiment, as described above, the top hat body 60 and the nozzle fixing portion 400 may define a cavity 500 extending in the circumferential direction between the top hat body 60 and the nozzle fixing portion 400. The nozzle fixing portion 400 may include a plurality of second internal flow paths 402 that circumferentially fix a plurality of fuel nozzles (second fuel nozzles 46) and can supply compressed air to the plurality of fuel nozzles (second fuel nozzles 46). The plurality of second internal flow paths 402 may be in fluid communication with the cavity 500 extending in the circumferential direction. By forming the cavity 500 extending in the circumferential direction, the first internal flow path 61 of the top hat body 60 and the plurality of second internal flow paths 402 of the nozzle fixing portion 400 can be fluidly communicated. Therefore, the pressures of the purge air Pa ejected from the plurality of fuel nozzles (second fuel nozzles 46) can be made close to each other. Thus, variations in the flow rate of the purge air Pa ejected from the plurality of fuel nozzles (second fuel nozzles 46) can be suppressed.

[0059] In the combustor 4 according to one embodiment, the second inlet 402a may be provided at a position different from the first outlet 61b when viewed in the radial direction of the combustor 4. In the cavity 500, the second inlet 402a, which is the inlet of the second internal flow path 402, is provided at a position away from the first outlet 61b, which is the outlet of the first internal flow path 61, so that the pressures of the purge air Pa ejected from the plurality of fuel nozzles (second fuel nozzles 46) can be made approximately the same. As a result, variations in the flow rate of the purge air Pa ejected from the plurality of fuel nozzles (second fuel nozzles 46) can be suppressed.

[0060] In the combustor 4 according to one embodiment, the second inlet 402a may be provided at a position different from the first outlet 61b in at least one of the axial direction or the circumferential direction of the combustor 4. Also, in the example shown in FIG. 4, the second inlet 402a is provided on the downstream side in the axial direction of the combustor 4 with respect to the first outlet 61b, but it may be provided on the upstream side in the axial direction of the combustor 4 with respect to the first outlet 61b. That is, in the combustor 4 according to one embodiment, the second inlet 402a may be provided on the upstream side in the axial direction compared to the example shown in FIG. 4, and the first outlet 61b may be provided on the downstream side in the axial direction compared to the example shown in FIG. 4.

[0061] In the combustor 4 according to one embodiment, the flow path cross-sectional area of the cavity 500 at the downstream end 511 in the axial direction of the cavity 500 when viewed in the axial direction of the combustor 4 may be smaller than the flow path cross-sectional area of the cavity 500 at the axial position of the second inlet 402a. Thereby, it is possible to suppress the entry of fuel and the like injected from the third fuel nozzle 70 into the cavity 500 from the downstream side in the axial direction.

[0062] In the combustor 4 according to one embodiment, the compressed air in the cavity 500 is configured to be ejected from the downstream end 511 to the air passage 54 through the downstream region 510. Therefore, the entry of fuel and the like injected from the third fuel nozzle 70 into the cavity 500 from the downstream side in the axial direction is further suppressed.

[0063] In addition, in the combustor 4 according to one embodiment, the radial height of the cavity 500 in the downstream region 510 may be zero, that is, in the downstream region 510, there may be substantially no gap between the inner peripheral surface 63a of the annular protrusion 63 of the top hat body 60 and the outer peripheral surface 420a of the main body 420 of the nozzle fixing portion 400.

[0064] In the combustor 4 according to other embodiments, the second internal flow path 402 may be connected to the first internal flow path 401 on a one-to-one basis. Thereby, it may not be necessary to provide the cavity 500.

[0065] In the combustor 4 according to some embodiments, as described above, the top hat body 60 may have a third internal flow path 69A for supplying fuel to the third fuel nozzle 70 which is a flow path injection nozzle fixed to the top hat body 60. The first internal flow path 61 may intersect the third internal flow path 69A when viewed in the circumferential direction of the combustor 4. Thereby, the first internal flow path 61 can be reasonably arranged in the top hat body 60.

[0066] The present disclosure is not limited to the above-described embodiments, and also includes forms obtained by modifying the above-described embodiments and forms obtained by appropriately combining these forms.

[0067] The content described in each of the above embodiments is understood as follows, for example. (1) The combustor 4 according to at least one embodiment of the present disclosure is a combustor 4 that burns compressed air supplied from the compressor 2 together with fuel. The combustor 4 according to at least one embodiment of the present disclosure includes a second fuel nozzle 46 which is at least one fuel nozzle having a fuel flow path 462 for supplying fuel and a purge air flow path 461 for ejecting purge air Pa. The combustor 4 according to at least one embodiment of the present disclosure includes a nozzle fixing portion 400 for fixing the second fuel nozzle 46 which is at least one fuel nozzle. The combustor 4 according to at least one embodiment of the present disclosure includes a top hat body 60 disposed on the outer peripheral side of at least a part of the nozzle fixing portion 400. The top hat body 60 has a first internal flow path 61 capable of supplying compressed air from a cavity 33 which is a space on its outer peripheral side to the nozzle fixing portion 400. The nozzle fixing portion 400 has a second internal flow path 402 capable of supplying the compressed air supplied from the first internal flow path 61 to the purge air flow path 461 of the second fuel nozzle 46 which is a fuel nozzle.

[0068] According to the configuration of (1) above, compressed air with relatively little pressure loss supplied from the compressor 2 can be supplied as purge air Pa to the second fuel nozzle 46 which is a fuel nozzle while suppressing heat loss. Thereby, in the gas turbine 1 including the combustor 4 having the configuration of (1) above, heat loss can be suppressed.

[0069] (2) In some embodiments, in the configuration of (1) above, the first internal flow path 61 may have a first inlet 61a which is an inlet of the first internal flow path 61 and a first outlet 61b which is an outlet located radially inside the combustor 4 relative to the first inlet 61a. The first outlet 61b may be formed in the inner peripheral portion 60a of the top hat body 60 facing the nozzle fixing portion 400.

[0070] According to the configuration of (2) above, the location where the first outlet 61b is formed is reasonable for fluidly connecting the first internal flow path 61 formed in the top hat body 60 and the second internal flow path 402 formed in the nozzle fixing portion 400.

[0071] (3) In some embodiments, in the configuration of (1) or (2) above, the second internal flow path 402 may have a second inlet 402a which is the inlet of the second internal flow path 402, and a second outlet 402b which is an outlet connected to the purge air flow path 461 of the fuel nozzle (second fuel nozzle 46). The second inlet 402a may be formed on the outer peripheral portion 400a of the nozzle fixing portion 400 facing the top hat body 60.

[0072] According to the configuration of (3) above, the location where the second inlet 402a is formed is reasonable for fluidly communicating the first internal flow path 61 formed in the top hat body 60 and the second internal flow path 402 formed in the nozzle fixing portion 400.

[0073] (4) In some embodiments, in any of the configurations of (1) to (3) above, the top hat body 60 and the nozzle fixing portion 400 may define a cavity 500 extending in the circumferential direction between the top hat body 60 and the nozzle fixing portion 400. The nozzle fixing portion 400 may include a plurality of second internal flow paths 402 that circumferentially fix a plurality of fuel nozzles (second fuel nozzles 46) and can supply compressed air to the plurality of fuel nozzles (second fuel nozzles 46). The plurality of second internal flow paths 402 may be in fluid communication with the cavity 500 extending in the circumferential direction.

[0074] According to the configuration of (4) above, by forming the cavity 500 extending in the circumferential direction, the first internal flow path 61 of the top hat body 60 and the plurality of second internal flow paths 402 of the nozzle fixing portion 400 can be fluidly communicated. Therefore, the pressures of the purge air Pa ejected from the plurality of fuel nozzles (second fuel nozzles 46) can be made close to each other. Thus, variations in the flow rate of the purge air Pa ejected from the plurality of fuel nozzles (second fuel nozzles 46) can be suppressed.

[0075] (5) In some embodiments, in the configuration of (4) above, the first internal flow path 61 may have a first inlet 61a which is the inlet of the first internal flow path, and a first outlet 61b which is an outlet located radially inward of the combustor 4 relative to the first inlet 61a. The second internal flow path 402 may have a second inlet 402a which is the inlet of the second internal flow path 402, and a second outlet 402b which is an outlet connected to the purge air flow path 461 of the fuel nozzle (second fuel nozzle 46). The second inlet 402a may be provided at a position different from that of the first outlet 61b when viewed from the radial direction of the combustor 4.

[0076] According to the configuration of (5) above, in the cavity 500, by providing the second inlet 402a, which is the inlet of the second internal flow path 402, at a position away from the first outlet 61b, which is the outlet of the first internal flow path 61, the pressures of the purge air Pa injected from the plurality of fuel nozzles (second fuel nozzles 46) can be made uniform. As a result, variations in the flow rate of the purge air Pa injected from the plurality of fuel nozzles (second fuel nozzles 46) can be suppressed.

[0077] (6) In some embodiments, in the configuration of (4) or (5) above, the second internal flow path 402 may have a second inlet 402a which is the inlet of the second internal flow path 402, and a second outlet 402b which is an outlet connected to the purge air flow path 461 of the fuel nozzle (second fuel nozzle 46). When viewed from the axial direction of the combustor 4, the flow path cross-sectional area of the cavity 500 at the downstream end portion 511 in the axial direction of the cavity 500 may be smaller than the flow path cross-sectional area of the cavity 500 at the axial position of the second inlet 402a.

[0078] According to the configuration of (6) above, it is possible to suppress fuel and the like from entering the cavity 500 from the downstream side of the cavity 500.

[0079] (7) In some embodiments, in any of the configurations of (1) to (3) above, the second internal flow path 402 may be connected to the first internal flow path 61 on a one-to-one basis.

[0080] According to the configuration of (7) above, it may not be necessary to provide the cavity 500.

[0081] (8) In some embodiments, in any of the configurations of (1) to (7) above, the top hat body 60 may have a third internal flow path 69A for supplying fuel to a third fuel nozzle 70 which is a flow path injection nozzle fixed to the top hat body 60. The first internal flow path 61 may intersect the third internal flow path 69A when viewed in the circumferential direction of the combustor 4.

[0082] According to the configuration of (8) above, the first internal flow path 61 can be arranged in the top hat body 60 without difficulty.

[0083] (9) The gas turbine 1 according to at least one embodiment of the present disclosure includes a compressor 2, a combustor 4 having any of the configurations of (1) to (8) above, and a turbine 6 configured to be driven by combustion gas from the combustor 4.

[0084] According to the configuration of (9) above, since the combustor 4 having the configuration of (1) above is provided, heat loss in the gas turbine 1 can be suppressed.

Explanation of reference numerals

[0085] 1 Gas turbine 2 Compressor 4 Combustor 6 Turbine 38 First combustion burner 40 First fuel nozzle 44 Second combustion burner 46 Second fuel nozzle 60 Top hat body 61 First internal flow path 61a First inlet 62b First outlet 69 Second connection passage 69A Third internal flow path 70 Third fuel nozzle 400 Nozzle fixing part 402 Second internal flow path 402a Second inlet 402b Second Outlet 500 Cavity

Claims

1. A combustor that burns compressed air supplied from a compressor together with fuel, at least one fuel nozzle having a fuel flow path for supplying the fuel and a purge air flow path for ejecting purge air, a nozzle fixing portion for fixing the at least one fuel nozzle, a top hat body disposed on an outer peripheral side of at least a part of the nozzle fixing portion, comprising the top hat body has a first internal flow path capable of supplying the compressed air from a space on its outer peripheral side to the nozzle fixing portion, the nozzle fixing portion has a second internal flow path capable of supplying the compressed air supplied from the first internal flow path to the purge air flow path of the fuel nozzle, Combustor.

2. The first internal flow path has a first inlet that is an inlet of the first internal flow path and a first outlet that is an outlet located radially inward of the combustor with respect to the first inlet, the first outlet is formed in an inner peripheral portion of the top hat body facing the nozzle fixing portion The combustor according to claim 1.

3. The second internal flow path has a second inlet that is an inlet of the second internal flow path and a second outlet that is an outlet connected to the purge air flow path of the fuel nozzle, the second inlet is formed in an outer peripheral portion of the nozzle fixing portion facing the top hat body The combustor according to claim 1 or 2.

4. The top hat body and the nozzle fixing portion define a cavity extending in the circumferential direction between the top hat body and the nozzle fixing portion, the nozzle fixing portion fixes a plurality of the fuel nozzles in the circumferential direction and includes a plurality of the second internal flow paths capable of supplying the compressed air to the plurality of fuel nozzles, The plurality of the second internal flow paths are in fluid communication with a cavity extending in the circumferential direction. The combustor according to claim 1 or 2.

5. The first internal flow path has a first inlet that is an inlet of the first internal flow path and a first outlet that is an outlet located radially inward of the combustor relative to the first inlet. The second internal flow path has a second inlet that is an inlet of the second internal flow path and a second outlet that is an outlet connected to the purge air flow path of the fuel nozzle. The second inlet is provided at a position different from the first outlet when viewed from the radial direction of the combustor. The combustor according to claim 4.

6. The second internal flow path has a second inlet that is an inlet of the second internal flow path and a second outlet that is an outlet connected to the purge air flow path of the fuel nozzle. When viewed from the axial direction of the combustor, a flow path cross-sectional area of the cavity at a downstream end portion in the axial direction of the cavity is smaller than a flow path cross-sectional area of the cavity at the axial position of the second inlet. The combustor according to claim 4.

7. The second internal flow paths are connected to the first internal flow paths on a one-to-one basis. The combustor according to claim 1 or 2.

8. The top hat body has a third internal flow path for supplying fuel to a flow path injection nozzle fixed to the top hat body. The first internal flow path intersects the third internal flow path when viewed from the circumferential direction of the combustor. The combustor according to claim 1 or 2.

9. The compressor, The combustor according to claim 1 or 2, A turbine configured to be driven by combustion gas from the combustor, and comprising a gas turbine.

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