Combustor and gas turbine equipped with the same

A combustor includes a combustion tube which has a tubular shape around an axis; a secondary fuel nozzle which is able to inject a secondary fuel in a radially inner direction with respect to the axis, inside the combustion tube; a fuel manifold which is disposed external to the combustion tube, and defines a fuel space which is able to temporarily store the secondary fuel; and a support which supports the fuel manifold with a gap extending radially from the combustion tube. The support has a support plate which is separated from the combustion tube by the gap and spreads in a circumferential direction with respect to the axis, and a support leg which is attached to the combustion tube and supports the support plate to define the gap between the support plate and the combustion tube.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed from Japanese Patent Application No. 2022-068230, filed Apr. 18, 2022, the content of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a combustor and a gas turbine equipped with the same.

BACKGROUND ART

A gas turbine includes a compressor that compresses air, a combustor that combusts fuel with the air compressed by the compressor to generate combustion gas, and a turbine that is driven by the combustion gas from the combustor.

The combustor described in Patent Literature 1 below has a combustion tube for a transition piece) in which fuel is burned, a plurality of nozzles which inject the fuel into the combustion tube, and a fuel manifold. The combustor has a tubular shape around a combustor axis. Here, for the convenience of the following description, a direction in which the combustor axis extends will be referred to as an axial direction, and among both sides in the axial direction, one side will be referred to as a proximal end side and the other side will be referred to as a distal end side. The nozzle has a primary fuel nozzle and a secondary fuel nozzle. The primary fuel nozzle is disposed on the proximal end side of the combustion tube and injects the primary fuel toward the distal end side in the combustion tube. The secondary fuel nozzle is attached to the combustion tube at a position closer to the distal end side than the primary fuel nozzle, and injects the secondary fuel radially inward into the combustion tube. The fuel manifold is an annular space with respect to the combustor axis, and forms a fuel space in which the secondary fuel can be temporarily stored. An inward radial edge of the fuel space is defined by the combustion tube. Therefore, a part of the fuel manifold is formed by a part of the combustion tube.

CITATION LIST

Patent Literature

Patent Literature 1

Published Japanese Translation No. 2010-539438 of the PCT international Publication

SUMMARY

The temperature of the combustion tube is extremely high when the fuel is burning inside. On the other hand, the temperature of the fuel manifold depends on the temperature of the fuel supplied to a fuel space when the fuel is burning inside the combustion tube, and does not reach as high a temperature as the combustion tube. Specifically, when the fuel is burning inside the combustion tube, a temperature difference between the temperature of the combustion tube and the temperature of the fuel manifold becomes several hundred degrees or more. As a result, an extremely high stress is generated in a connecting portion between the combustion tube and the fuel manifold, and the durability of the combustion tube and fuel manifold is lowered.

Therefore, an object of the present disclosure is to provide a technology capable of enhancing the durability of the combustion tube and the fuel manifold.

A combustor as an aspect according to the present disclosure for achieving the above object includes a combustion tube which has a tubular shape around an axis and is able to burn fuel on an inner peripheral side; a primary fuel nozzle which is able to inject a primary fuel in a direction having a directional component toward a distal end side among the distal end side and a proximal end side in an axial direction in which the axis extends, inside the combustion tube; a secondary fuel nozzle which is attached to the combustion tube at a position closer to the distal end side than the primary fuel nozzle and able to inject a secondary fuel toward a radially inner side among the radially inner side and a radially outer side in a radial direction with respect to the axis, inside the combustion tube; a fuel manifold which is disposed on an outer peripheral side of the combustion tube, has an annular shape with respect to the axis, and forms a fuel space which is able to temporarily store the secondary fuel and communicates with the secondary fuel nozzle; and a support which supports the fuel manifold with a gap from the combustion cylinder in the radial direction. The support has a support plate which is separated from the combustion tube to the radially outer side and spreads in a circumferential direction with respect to the axis, and a support leg which is attached to the combustion tube and supports the support plate so that a space is formed between the support plate and the combustion tube. The fuel manifold is disposed on the radially outer side of the support plate and supported by the support.

The temperature of the combustion tube is extremely high when the fuel is burning inside. On the other hand, the temperature of the fuel manifold depends on the temperature of the fuel supplied to the fuel space when the fuel is burning inside the combustion tube and does not become as high as the combustion tube. Therefore, if the fuel manifold is directly connected to the outer peripheral surface of the combustion tube, an extremely high tress is generated in the connecting portion between the combustion tube and the fuel manifold.

In the present embodiment, since the support is interposed between the combustion tube and the fuel manifolds, a temperature gradient from the combustion tube to the fuel manifold is gentler than a temperature gradient when the fuel manifold is directly connected to the outer peripheral surface of the combustion tube. Moreover, the support of the present embodiment has a shape that is easily deformed. Therefore, in the present embodiment, the stress generated from the combustion tube to the fuel manifold can be suppressed to be low, and the durability of the combustion tube and the fuel manifold can be enhanced.

A gas turbine as an aspect according to the present disclosure for achieving the above object includes the combustor as above one aspect; a compressor which compresses air and is able to generate compressed air used for combustion of fuel inside the combustion tube; and a turbine which is able to be driven by a combustion gas generated by combustion of fuel in the combustor tube.

In an aspect of the present disclosure, it is possible to enhance the durability of the combustion tube and the fuel manifold.

DESCRIPTION OF EMBODIMENTS

Various embodiments of a combustor according to the present disclosure and a gas turbine equipped with the same will be described in detail below with reference to the drawings.

<Embodiment of Gas Turbine>

An embodiment of a gas turbine will be described with reference toFIG.1.

As shown inFIG.1, a gas turbine10in the present embodiment includes a compressor20capable of compressing outside air A to generate compressed air, a plurality of combustors40capable of burning fuel F in compressed air to generate combustion gas G, and a turbine30that can be driven by the combustion gas G.

The compressor20has a compressor rotor21that rotates about a rotor axis Ar, a compressor casing25that covers the compressor rotor21, and a plurality of stator blade rows26. The turbine30has a turbine rotor31that rotates around the rotor axis Ar, a turbine casing35that covers the turbine rotor31, and a plurality of stator blade rows36. In the following description, a direction in which the rotor axis Ar extends is referred to as a rotor axial direction Da, one side of both sides in the rotor axial direction Da is referred to as an axial upstream side Dau, and the other side thereof is referred to as an axial downstream side Dad.

The compressor20is disposed on the axial upstream side Dau with respect to the turbine30. The compressor rotor21and the turbine rotor31are positioned on the same rotor axis Ar and connected to each other to form the gas turbine rotor11. For example, a rotor of a generator GEN is connected to the gas turbine rotor11. The gas turbine10further includes an intermediate casing14disposed between the compressor casing25and the turbine casing35. The compressed air from the compressor20flows into the intermediate casing14. A plurality of combustors40are attached to the intermediate casing14side by side in a circumferential direction with respect to the rotor axis Ar. The compressor casing25, the intermediate casing14and the turbine casing35are connected together to form the gas turbine casing15.

The compressor rotor21has a rotor shaft22extending in the rotor axial direction Da around the rotor axis Ar, and a plurality of rotor blade rows23attached to the rotor shaft22. The plurality of rotor blade rows23are aligned in the rotor axial direction Da. Each rotor blade row23is made up of a plurality of rotor blades aligned in a circumferential direction with respect to the rotor axis Ar. Any one stator blade row26of the plurality of stator blade rows26is disposed on the axial downstream side Dad of each of the plurality of rotor blade rows23. Each stator blade row26is provided inside the compressor casing25. Each stator blade row26is made up of a plurality of stator blades aligned in the circumferential direction with respect to the rotor axis Ar.

The turbine rotor31has a rotor shaft32extending in the rotor axial direction Da around the rotor axis Ar, and a plurality of rotor blade rows33attached to the rotor shaft32. The plurality of rotor blade rows33are aligned in the rotor axial direction Da. Each rotor blade row33is made up of a plurality of rotor blades aligned in the circumferential direction with respect to the rotor axis Ar. Any one stator blade row36of the plurality of stator blade rows36is disposed at the axial upstream side Dau of each of the plurality of rotor blade rows33. Each stator blade row36is provided inside the turbine casing35. Bach stator blade rows36is made up of a plurality of stator blades aligned in the circumferential direction with respect to the rotor axis Ar. In an annular space between the inner peripheral side of the turbine casing35and the outer peripheral side of the rotor shaft32, a region in which the plurality of stator blade rows36and the plurality of rotor blade rows33are disposed forms a combustion gas flow path39through which the combustion gas G from the combustor40flows.

A fuel line46is connected to the combustor40. The combustor40is able to burn the fuel F from the fuel line46in the compressed air from the compressor20to produce the combustion gas G.

A first embodiment of the combustor will be described with reference toFIGS.2to4.

As shown inFIG.2, the combustor40in the present embodiment includes a flange41, an inner tube43, a combustion tube (or tail tube)44, a plurality of primary fuel pipes47, a plurality of primary fuel nozzles48, a secondary fuel pipe51, a branched secondary fuel pipe52, a plurality of secondary fuel nozzles53, a fuel manifold55, and a plurality of supports57.

The flange41extends in a radial direction from the combustor axis Ac. Both the inner tube43and the combustion tube44are disposed inside the intermediate casing14. In addition, both the inner tube43and the combustion tube44have a tubular shape around the combustor axis Ac. Here, for the convenience of the following description, a direction in which the combustor axis (hereinafter referred to simply as an axis) Ac extends is referred to as an axial direction Dc. Among both sides in the axial direction Dc, one side is referred to as a distal end side Dct and the other side is referred to as a proximal end side Deb. Further, as shown inFIG.1, the distal end side Dct is the axial downstream side Dad in the rotor axial direction Da, and the proximal end side Deb is the axial upstream side Dan in the rotor axial direction Da. Further, the axis Ac is inclined with respect to the rotor axis Ar to approach the rotor axis Ar toward the distal end side Dct. The circumferential direction with respect to the axis Ac is simply referred to as a circumferential direction Dcc. Also, the radial direction with respect to the axis Ac is simply referred to as a radial direction Dr. A side closer to the axis Ac in the radial direction Dr is referred to as a radially inner side Dri, and aside opposite to the radially inner side Dri is referred to as a radially outer side Dro.

A combustor attachment hole14hwhich penetrates from the outside of the intermediate casing14into the intermediate casing14is formed in the intermediate casing14. The flange41is attached to the intermediate casing14with bolts42to block the combustor attachment hole14h. The inner tube43is attached to the flange41. A plurality of primary fuel nozzles48are disposed on the inner peripheral side of the inner tube43. The combustion tube44is connected to the portion of the distal end side Dct of the inner tube43via a sealing member or the like. The combustion tube44is supported by a tube support45or the like fixed to the inner surface of the intermediate casing14.

All of the plurality of primary fuel nozzles48extend in the axial direction De and am formed with holes for injecting fuel. All of the plurality of primary fuel nozzles48are able to inject the primary fuel in a direction having a directional component toward the distal end side Dt. All of the plurality of primary fuel nozzles48are fixed to the flange41. Among the plurality of primary fuel nozzles48, one nozzle is a pilot nozzle48p, and the other plurality of nozzles are main nozzles48m. The pilot nozzle48pis disposed on the axis Ac. The plurality of main nozzles48mare aligned in the circumferential direction Dcc around the pilot nozzle48p.

All of the plurality of primary fuel pipes47are pipes branched front the fuel line46and fixed to the flange41. Among the plurality of primary fuel pipes47, one fuel pipe is a pilot fuel pipe47p, and the other plurality of fuel pipes are main fuel pipes47m. The pilot fuel pipe47pis connected to the pilot nozzle48p. Each of the plurality of main fuel pipes47mis connected to one main nozzle48mof the plurality of main nozzles48m.

The plurality of secondary fuel nozzles53are attached to the combustion tube44side by side in the circumferential direction Dcc at positions closer to the distal end side Dct than the plurality of primary fuel nozzles48. All of the plurality of secondary fuel nozzles53are able to inject the secondary fuel toward the radially inner side Dri inside the combustion tube44.

The fuel manifold55is disposed on the outer peripheral side of the combustion tube44, on the side closer to the distal end side Dct than the primary fuel nozzle48and on the side closer to the proximal end side Dcb than the secondary fuel nozzle53. The fuel manifold55is formed in an annular shape with respect to the axis Ac. The fuel manifold55forms an annular shape with respect to the axis Ac, and forms a fuel space56in which the secondary fuel can be temporarily stored. The aforementioned secondary fuel pipe51is connected to the fuel manifold55. The secondary fuel pipe51is also a pipe branched from the fuel line46and fixed to the flange41. The fuel manifold55and the plurality of secondary fuel nozzles53are connected by the plurality of branched secondary fuel pipes52. Therefore, the fuel manifold55communicates with the plurality of secondary fuel nozzles53via the plurality of branched secondary fuel pipes52so that the secondary fuel in the fuel space56can be supplied to the plurality of secondary fuel nozzles53.

As shown inFIGS.3and4, the plurality of supports57support the fuel manifold55with a gap between them and the combustion tubes44in the radial direction Dr. The plurality of supports57are aligned in the circumferential direction Dcc. The support57has a support plate58that is spaced apart from the combustion tube44to the radially outer side Dro and spreads in the circumferential direction Dcc, and a plurality of support legs59that are attached to the combustion tube44and support the support plate58such that a space is formed between the support plate58and the combustion tube44. Each of the plurality of support legs59is a plate-like member extending in the circumferential direction Dce. Among the plurality of support legs59, some support legs59are connected to an edge of the proximal end side Deb of the support plate58, and the remaining partial support legs59are connected to an edge of the distal end side Dct of the support plate58. Some support legs59and remaining partial support legs59are opposite to each other with a gap in the axial direction Dc. Therefore, a space is formed between the support plate58and the combustion tube44.

A pan of the annular fuel manifold55is connected to the support plate58of at least one support57among the plurality of supports57by welding or the like.

The temperature of the combustion tube44is extremely high when the fuel is burning inside. On the other hand, the temperature of the fuel manifold55depends on the temperature of the fuel supplied to the fuel space56when the fuel is burning inside the combustion tube44and does not become as high as the combustion tube44. Therefore, if the fuel manifold55is directly connected to the outer peripheral surface of the combustion tube44, an extremely high stress is generated in the connecting portion between the combustion tube44and the fuel manifold55.

On the other hand, in the present embodiment, since the support57is interposed between the combustion tube44and the fuel manifold55, a temperature gradient from the combustion tube44to the fuel manifold55is gentler than a temperature gradient when the fuel manifold55is directly connected to the outer peripheral surface of the combustion tube44. Moreover, the support57of the present embodiment has a shape that is easily deformed. Therefore, in the present embodiment, the stress generated from the combustion tube44to the fuel manifold55can be suppressed to be low, and the durability of the combustion tube44and the fuel manifold55can be enhanced.

A second embodiment of the combustor will be described with reference toFIGS.5and6.

The combustor in the present embodiment includes a flange41, an inner tube43, a combustion tube44, a plurality of primary fuel pipes47, a plurality of primary fuel nozzle48, a secondary fuel pipe51, a branched secondary fuel pipe52, a plurality of secondary fuel nozzles53, and a fuel manifold55a, as in the combustor40in the first embodiment described usingFIG.2. Furthermore, as shown inFIGS.5and6, the combustor40ain the present embodiment includes an acoustic attenuator60, as shown inFIGS.5and6.

The acoustic attenuator60has an acoustic cover61that forms an acoustic space62on the outer peripheral side of the combustion tube44together with a part of the plate that forms the combustion tube44. A plurality of through-holes63through which the inside of the combustion tube44and the acoustic space62communicates with each other are formed in a part of the plate forming the combustion tube44that defines a part of the acoustic space62.

The acoustic cover61has a top plate65which is spaced from the combustion tube44to the radially outer side Dro, and a pair of side peripheral plates66which connects the top plate65and the combustion tube44. The top plate65is opposite to the outer surface of the combustion tube44, and has an annular shape around the axis Ac. The pair of side peripheral plates66form an annular shape around the axis Ac, and are opposite to each other with a gap in the axial direction Dc. Among the pair of side peripheral plates66, one side peripheral plate66is connected to the edge of the proximal end side Deb of the top plate65, and the other side peripheral plate66is connected to the edge of the distal end side Dct of the top plate65.

As in the first embodiment, the fuel manifold55ais able to supply the secondary fuel in the fuel space56ato the plurality of secondary fuel nozzles53, and communicates with the plurality of secondary fuel nozzles53via the plurality of branched secondary fuel pipes52.

The fuel manifold55ais disposed on the radially outer side Dro of the acoustic cover61described above and connected to the acoustic cover61. Therefore, the acoustic cover61in the present embodiment functions as a support57afor the fuel manifold55a. Specifically, the top plate65of the acoustic cover61constitutes the support plate58aof the support57a, and the pair of side peripheral plates66of the acoustic cover61constitute the support legs59aof the support57a.

As described above, also in the present embodiment, since the acoustic cover61functions as the support57a, as in the first embodiment, the stress generated from the combustion tube44to the fuel manifold55acan be suppressed to a low level, and the durability of the combustion tube44and the fuel manifold55acan be enhanced.

Furthermore, in the present embodiment, as described above, since the acoustic cover61functions as the support57a, there is no need to provide a separate support, and the number of constituent components of the combustor40acan be reduced.

Also, in the present embodiment, a part of the fuel manifold55ais formed by including a part of the top plate65of the acoustic cover61. Therefore, in the present embodiment, when the fuel manifold55ais provided on the radially outer side Dro of the acoustic cover61, the structures of the acoustic cover61and the fuel manifold55acan be simplified.

A third embodiment of the combustor will be described with reference toFIGS.7to9.

As shown inFIG.7, the combustor40bin the present embodiment includes a flange41, an inner tube43, a combustion tube44, a plurality of primary fuel pipes47, a plurality of primary fuel nozzles48, a secondary fuel pipe51, a branched secondary fuel pipe52, a plurality of secondary fuel nozzles53, and a fuel manifold55b, as in the combustors40and40ain above each embodiment. Furthermore, the combustor40bin the present embodiment includes an acoustic attenuator60A, as in the combustor40ain the second embodiment.

As shown inFIGS.8and9, the acoustic attenuator60A in the present embodiment has a first acoustic attenuator60Aa, and a second acoustic attenuator60Ab disposed on the radially outer side Dro of the first acoustic attenuator60Aa. The first acoustic attenuator60Aa is a resonator that suppresses noise using the principle of Helmholtz resonance, and is sometimes called an acoustic liner. On the other hand, the second acoustic attenuator60Ab is a resonator that suppresses noise in a specific frequency range using the principle of air column resonance, and is sometimes called an acoustic damper.

The first acoustic attenuator60Aa has a first acoustic cover61athat forms a first acoustic space62aon the outer peripheral side of the combustion tube44together with a part of the plate that forms the combustion tube44. A plurality of through-holes63through which the inside of the combustion tube44and the first acoustic space62acommunicate with each other are formed in a part of the plate that forms the combustion tube44, which defines a part of the first acoustic space62a. The first acoustic cover61ahas a first top plate65athat is spaced apart from the combustion tube44to the radially outer side Dro, and a pair of first side peripheral plates66athat connects the first, top plate65aand the combustion tube44. The first top plate65ais opposite to the outer surface of the combustion tube44, and has an annular shape around the axis Ac. This first top plate65adefines the edge of the radially outer side Dro of the first acoustic space62a. The pair of first side peripheral plates66aform an annular shape around the axis Ac, and are opposite to each other with a gap in the axial direction Dc. Among the pair of first side peripheral plates66a, the first proximal end side peripheral plate66abon the proximal end side Db is connected to the edge of the proximal end side Dcb of the first top plate65a. Further, among the pair of first side peripheral plates66a, the first distal end side peripheral plate66aton the distal end side Dct is connected to the edge of the distal end side Dct of the first top plate65a.

The second acoustic attenuator60Ab has a second acoustic cover61bthat forms a second acoustic space62bon the radially outer side Dro of the first acoustic cover61atogether with a part of the first top plate65a. A plurality of through-holes64through which the first acoustic space62aand the second acoustic space62bcommunicate with each other is formed in a part of the first top plate65athat defines the second acoustic space62b. The second acoustic cover61bhas a second top plate65bthat is spaced apart from the first top plate65ato the radially outer side Dro, and a pair of second side peripheral plates66bthat connect the second top plate65band the first top plate65a. The second top plate65bis opposite to the first top plate65a, and has an annular shape around the axis Ac. The second top plate65bdefines the edge of the radially outer side Dro of the second acoustic space62b. The pair of second side peripheral plates66bform an annular shape around the axis Ac, and are opposite to each other with a gap in the axial direction Dc. Among the pair of second side peripheral plates66), the second proximal end side peripheral plate661bon the proximal end side Deb is connected to the edge of the proximal end side Dcb of the second top plate65b. Among the pair of second side peripheral plates66b, the second distal end side peripheral plate66bton the distal end side Dt is connected to the edge of the distal end side Dct of the second top plate65b.

The fuel manifold55bis disposed so that the fuel space56bis located on the side closer to the radially outer side Dro than the first top plate65aand on the side closer to the distal end side Dct than the second distal end side peripheral plate66bt. A distance d1from an outer peripheral surface of the combustion tube44to the edge of the radially outer side Dro of the fuel manifold55bis equal to or less than a distance d2from the outer peripheral surface of the combustion tube44to the edge of the radially outer side Dro of the second top plate65b. A portion of the combustor40bincluding the combustion tube44is inserted into the intermediate casing14from the combustor attachment hole14hof the intermediate casing14when assembled to the intermediate casing14. Therefore, the size of the cross section perpendicular to the axis Ac at this insertion portion is restricted by the size of the combustor attachment hole14h. Therefore, the distance d1from an outer peripheral surface of the combustion tube44to the edge of the radially outer side Dro of the fuel manifold55bis restricted as described above to ensure an ease of assembly of the combustor40bto the intermediate casing14.

The fuel manifold55bis disposed on the radially outer side Dro of the first acoustic cover61adescribed above and connected to the first acoustic cover61a. Therefore, the first acoustic cover61ain the present embodiment functions as a support57bfor the fuel manifold55h. Specifically, the first top plate65aof the first acoustic cover61aconstitutes the support plate58bof the support57b, and a pair of first side peripheral plates66aof the first acoustic cover61aconstitute the support legs59bof the support57b.

As described above, also in the present embodiment, since the first acoustic cover61afunctions as the support57b, the stress generated front the combustion tube44to the fuel manifold55bcan be suppressed as in the above embodiments, and the durability of the combustion tube44and the fuel manifold55bcan be enhanced.

Furthermore, in the present embodiment, as in the second embodiment, since the first acoustic cover61afunctions as the support57b, there is no need to provide a separate support, and the number of constituent components of the combustor40bcan be reduced.

Further, in the present embodiment, a part of the fuel manifold55bis formed to have a part of the second distal end side peripheral plate66btof the second acoustic cover61band a part of the first top plate65aof the first acoustic cover61a. Therefore, in the present embodiment, when the fuel manifold55bis provided on the radially outer side Dro of the first acoustic cover61aand on the distal end side Dct of the second acoustic cover61b, the structures of the first acoustic cover61a, the second acoustic cover61band the fuel manifold55bcan be simplified.

In the combustors40,40a, and40bin the above embodiments, the fuel manifolds55,55a, and55bare directly connected to the support plate58or the top plates65and65aof the acoustic covers61and61afunctioning as the support plate. However, as in the combustor40cshown inFIG.10, a manifold receiver67may be provided on the radially outer side Dro of the first top plate65aof the first acoustic cover61a, and the fuel manifold55cmay be connected to the manifold receiver67. That is, the support57cof the fuel manifold55cmay be made up of the top plate65aof the first acoustic cover61aas the support plate58b, the side peripheral plate66aof the first acoustic cover61aas the support leg59b, and the manifold receiver67.

By providing the manifold receiver67in this way, the temperature gradient from the combustion tube44to the fuel manifold55cbecomes gentler than the temperature gradient of a case where the manifold receiver67is not provided. Moreover, by providing the manifold receiver67, the support57cis more easily deformed than the case where the manifold receiver67is not provided. Therefore, by providing the manifold receiver67, the stress generated from the combustion tube44to the fuel manifold55ccan be suppressed to a lower level than the case where the manifold receiver67is not provided, and the durability of the combustion tube44and the fuel manifold55ccan be enhanced.

Although the modified example shown inFIG.10is a modified example of the support57bin the third embodiment, the manifold receiver67may also be added to the support57in the first embodiment and the support57ain the second embodiment.

In each of the above embodiments and modified examples, the fuel manifolds55,55a,55b, and55cand the secondary fuel nozzle53are connected by the branched secondary fuel pipes52. However, as long as the fuel manifolds55,55a,55h, and55ccan be disposed so that the fuel manifolds55,55a,55b, and55care in contact with the secondary fuel nozzle53, the branched secondary fuel pipe52can be omitted.

In addition, the present disclosure is not limited to an embodiment and modified example described above. Various additions, changes, replacements, partial deletions, and the like are possible without departing from the conceptual idea and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

APPENDIX

The combustors40,40a,40h, and40cin the above embodiments are understood as follows, for example.(1) The combustors40,40a,40b, and40cof a first aspect hasa combustion tube44which has a tubular shape around an axis Ac and is able to burn fuel on an inner peripheral side, a primary fuel nozzle48which is able to inject a primary fuel in a direction having a directional component toward a distal end side Dct among the distal end side Dct and a proximal end side Deb in an axial direction Dc in which the axis Ac extends, inside the combustion tube44; a secondary fuel nozzle53which is attached to the combustion tube44at a position closer to the distal end side Dct than the primary fuel nozzle48and able to inject a secondary fuel toward a radially inner side Dri among the radially inner side Dri and a radially outer side Dro in the radial direction Dr with respect to the axis Ac, inside the combustion tube44; fuel manifolds55,55a,55b, and55cwhich are disposed on an outer peripheral side of the combustion tube44, have an annular shape with respect to the axis Ac, and form fuel spaces56,56aand56bwhich are able to temporarily store the secondary fuel and communicate with the secondary fuel nozzle53; and supports57,57a,57b, and57cwhich support the fuel manifolds55,55a,55b, and55cwith a gap from the combustion tube44in the radial direction Dr. The supports57,57a,57b, and57chave support plates58,58a, and58bwhich are separated from the combustion tube44to the radially outer side Dro and spread in a circumferential direction Dcc with respect to the axis Ac, and support legs59,59a, and59bwhich are attached to the combustion tube44, and support the support plates58,58a, and58bso that a space is formed between the support plates58,58a, and58band the combustion tube44. The fuel manifolds55,55a,55b, and55care disposed on the radially outer side Dro of the support plates58,58a, and58band supported by the supports57,57a,57b, and57c.

The temperature of the combustion tube44is extremely high when the fuel is burning inside. On the other hand, the temperatures of the fuel manifolds55,55a,55b, and55cdepend on the temperature of the fuel supplied to the fuel spaces56,56a, and56bwhen the fuel is burning inside the combustion tube44and do not become as high as the combustion tube44. Therefore, if the fuel manifolds55,55a,55b, and55care directly connected to the outer peripheral surface of the combustion tube44, an extremely high stress is generated in the connecting portion between the combustion tube44and the fuel manifolds55,55a,55b, and55c.

In the present embodiment, since the supports57,57a,57b, and57care interposed between the combustion tube44and the fuel manifolds55,55a,55b, and55c, a temperature gradient from the combustion tube44to the fuel manifolds55,55a,55b, and55cis gentler than a temperature gradient when the fuel manifolds55,55a,55b, and55care directly connected to the outer peripheral surface of the combustion tube44. Moreover, the supports57,57a,57b, and57cof the present embodiment have a shape that is easily deformed. Therefore, in the present embodiment, the stress generated from the combustion tube44to the fuel manifolds55,55a,55b, and55ccan be suppressed to be low, and the durability of the combustion tube44and the fuel manifolds55,55a,55b, and55ccan be enhanced.(2) According to the combustors40,40a,40b, and40cof a second aspect,in the combustors40,40a,40b, and40cof the first aspect, the support legs59,59a, and59bare connected to edges of the support plates58,58a, and58b.

In the present embodiment, the support legs59,59a, and59bare connected to the edges of the support plates58,58a, and58bso that a space is formed between the support plates58,58a, and58band the combustion tube44. Therefore, in this aspect, the supports57,57a,57b, and57care easily deformed, and the stress generated from the combustion tube44to the fuel manifolds55,55a,55b, and55ccan be suppressed to be low.(3) According to the combustor40of a third aspect,in the combustor40cof the first aspect or the second aspect, the support57chas a manifold receiver67provided on the radially outer side Dro of the support plate58b. The fuel manifold55cis connected to the manifold receiver67.

Since the support57chas the manifold receiver67, the temperature gradient from the combustion tube44to the fuel manifold55cbecomes gentler than the temperature gradient of a case where the manifold receiver67is not provided. Moreover, since the support57chas the manifold receiver67, the support57cis more easily deformed than the case where the manifold receiver67is not provided. Therefore, since the support57chas the manifold receiver67, the stress generated front the combustion tube44to the fuel manifold55ccan be suppressed to a lower level than the case where the manifold receiver67is not provided, and the durability of the combustion tube44and the fuel manifold55ccan be enhanced.(4) According to the combustors40,40a,40b, and40cof a fourth aspect.in the combustor40,40a,40b, and40cof any one of the first to third aspects, the combustor includes a branched secondary fuel pipe52which connects the fuel manifolds55,5a,55b, and55cand the secondary fuel nozzles53to deliver the secondary fuel in the fuel spaces56,56a, and56bto the secondary fuel nozzle53,(5) According to the combustors40a,40b, and40cof a fifth aspect.in the combustors40a,40b, and40cof any one of the first to fourth aspects, the combustor includes acoustic attenuators60and60Aa which have acoustic covers61and61aforming acoustic spaces62and62aon the outer peripheral side of the combustion tube44. The support plates58aand58band the support legs59aand59bof the supports57a,57b, and57care made up of at least a part of the acoustic covers61and61a.

In this aspect, since the support plates58aand58band the support legs59aand59bof the supports57a,57b, and57care made up of at least a pan of the acoustic covers61and61a, as in the first aspect, the stress generated from the combustion tube44to the fuel manifolds55a,55b, and55ccan be suppressed to be low, and the durability of the combustion tube44and the fuel manifolds55a,55b, and55ccan be enhanced.

Furthermore, in this aspect, since the acoustic covers61and61afunction as the supports57a,57b, and57c, there is no need to provide a separate support, and the number of constituent components of the combustors40a,40b, and40ccan be reduced.(6) According to combustors40band40cof a sixth aspect,in the combustors40band40caccording to the fifth aspect, the acoustic attenuator60A has a first acoustic attenuator60Aa, and a second acoustic attenuator60Ab disposed on the radially outer side Dro of the first acoustic attenuator60Aa. The first acoustic attenuator60Aa has a first acoustic cover61athat forms a first acoustic space62aon the outer peripheral side of the combustion tube44together with a part of the plate that forms the combustion tube44. The first acoustic cover61ahas a first top plate65athat extends in the circumferential direction Dcc apart from the combustion tube44toward the radially outer side Dro and defines an edge of the radially outer side Dro of the first acoustic space62a, and a first side peripheral plate66athat extends in the circumferential direction Dcc, connects an end of the first top plate65ain the axial direction Dc and the combustion tube44, and defines an edge of the first acoustic space62ain the axial direction Dx. The support plate58bof the supports57band57cis made up of the first top plate65a. The support legs59bof the supports57band57care made up of the first side peripheral plate66a.

Also in this aspect, as in the fifth aspect, since the support plate58band the support leg59bof the supports57band57care made up of at least a part of the acoustic cover61a, as in the first aspect, the stress generated from the combustion tube44to the fuel manifolds55band55ccan be suppressed to be low, and the durability of the combustion tube44and the fuel manifolds55band55ccan be enhanced.(7) According to the combustor40bin a seventh aspect,in the combustor40baccording to the sixth aspect, the second acoustic attenuator60Ab has a second acoustic cover61bthat forms a second acoustic space62bon the radially outer side Dro of the first acoustic cover61atogether with a part of the first top plate65a. The second acoustic cover61bhas a second top plate65bwhich extends in the circumferential direction Dcc apart from the first top plate65atoward the radially outer side Dro to define an edge of the radially outer side Dro of the second acoustic space62b, and a second side peripheral plate66bwhich extends in the circumferential direction Dcc and connects an end of the second top plate65bin the axial direction De and the first top plate65ato define an edge of the second acoustic space62bin the axial direction Dc. A distance d1from an outer peripheral surface of the combustion tube44to the edge of the radially outer side Dro of the fuel manifold55bis equal to or less than a distance d2from the outer peripheral surface of the combustion tube44to the edge of the radially outer side Dro of the second top plate65b.

In some cases, a portion of the combustor40bincluding the combustion tube44is inserted into the casing14from the combustor attachment hole14hof the casing14when assembled to the casing14of a case turbine. In this case, a size of a cross section perpendicular to the axis Ac at this insertion portion is restricted by a size of the combustor attachment hole14h. Therefore, the distance d1from an outer peripheral surface of the combustion tube44to the edge of the radially outer side Dro of the fuel manifold55bis restricted as described above to ensure an ease of assembly of the combustor40bto the casing14.(8) According to the combustor40bof an eighth aspect.in the combustor40bin the seventh aspect, the first side peripheral plate66ahas a first distal end side peripheral plate66atwhich is connected to the end of the distal end side Dct of the first top plate65a, and defines an edge of the distal end side Dct of the first acoustic space62a. The second side peripheral plate66hhas a second distal end side peripheral plate66btwhich is connected to the end of the distal end side Dct of the second top plate65b, and defines an edge of the distal end side Dct of the second acoustic space62b. The second distal end side peripheral plate66btis located to be closer to the proximal end side Dcb than the first distal end side peripheral plate66at. The fuel manifold55bis disposed so that the fuel space56bis located to be closer to the radially outer side Dro than the first top plate65aand closer to the distal end side DI than the second distal end side peripheral plate66bt.

In this aspect, it is possible to effectively utilize the space closer to the radially outer side Dro than the first top plate65aof the first acoustic cover61aand closer to the distal end side Dct than the second distal end side peripheral plate66btof the second acoustic cover61b.(9) According to the combustor40bof a ninth aspect,in the combustor40bof the eighth aspect, a part of the fuel manifold55bis formed to have a part of the second distal end side peripheral plate66btand a part of the first top plate65a.

In this aspect, when the fuel manifold55bis provided on the radially outer side Dro of the first acoustic cover61aand on the distal end side ti of the second acoustic cover61b, structures of the first acoustic cover61a, the second acoustic cover61b, and the fuel manifold55bcan be simplified.

For example, a gas turbine10in the above embodiment is understood as follows.(10) A gas turbine10of a tenth aspect includesthe combustors40,40a,40b, and40caccording to any one of the first to ninth aspects, a compressor20that compresses air and is able to generate a compressed air used for combustion of fuel inside the combustion tube44, and a turbine30that is able to be driven by a combustion gas generated by combustion of fuel in the combustion tube44.10Gas turbine11Gas turbine rotor14Intermediate casing14hCombustor attachment hole15Gas turbine casing20Compressor21Compressor rotor22Rotor shaft23Rotor blade ow25Compressor casing26Stator blade row30Turbine31Turbine rotor32Rotor haft33Rotor blade row35Turbine casing36Stator blade row39Combustion gas flow path40,40a,40b,40cCombustor41Flange42Bolt43Inner tube44Combustion tube (or tail tube)45Tube support46Fuel line47Primary fuel pipe47pPilot fuel pipe47mMain fuel pipe48Primary fuel nozzle48pPilot nozzle48mMain nozzle51Secondary fuel pipe52Branched secondary fuel pipe53Secondary fuel nozzle55,55a,55b,55cFuel manifold56,56a,56bFuel space57,57a,57b,57cSupport58,58a,58bSupport plate59,59a,59bSupport leg60,60A Acoustic attenuator60Aa First acoustic attenuator60Ab Second acoustic attenuator61Acoustic cover (support)61aFirst acoustic cover (support)61bSecond acoustic cover62Acoustic space62aFirst acoustic space62bSecond acoustic space63,64Through-hole65Top plate (support plate)65aFirst top plate (support plate)65bSecond top plate66Side peripheral plate (support leg)66aFirst side peripheral plate (support leg)66abFirst proximal end side peripheral plate66atFirst distal end side peripheral plate66bSecond side peripheral plate66bbSecond proximal end side peripheral plate66btSecond distal end side peripheral plate67Manifold receiverA Outside airF FuelG Combustion gasAr Rotor axisAc Combustor axis (or simply axis)Da Rotor axial directionDau Axial upstream sideDad Axial downstream sideDc Axial directionDcb Proximal end sideDct Distal end sideDcc Circumferential directionDr Radial directionDri Radially inner sideDro Radially outer side