Exhaust facility, and gas turbine comprising the same

Abstract

To restrain the inflow of exhaust gas between the inner peripheral side of an exhaust casing and the outer peripheral side of a first outside diffuser.SOLUTION: An exhaust facility comprises a first outside diffuser, a second outside diffuser, an exhaust casing covering the outer peripheral side of the first outside diffuser, an exhaust chamber covering the outside of the second outside diffuser, a first annular seal device, a second annular seal device, and a third annular seal device. The first annular seal device is arranged so as to be capable of restraining the inflow of exhaust gas between the first outside diffuser and the exhaust casing. The second annular seal device is arranged so as to be capable of restraining the inflow of the exhaust gas between the second outside diffuser and the exhaust chamber. The third annular seal device is arranged between the first annular seal device and the second annular seal device, and arranged so as to be capable of restraining the flow of the exhaust gas to the side of the first annular seal device.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an exhaust system that forms an exhaust flow path through which exhaust gas passes after rotating a turbine rotor of a gas turbine, and to a gas turbine equipped with the same. [Background technology]

[0002] A gas turbine includes a compressor that compresses outside air to generate compressed air, a combustor that mixes fuel with the compressed air and burns it to generate combustion gas, a turbine driven by the combustion gas, and exhaust equipment. The turbine has a turbine rotor that can rotate about an axis and a turbine casing that covers the outer periphery of the turbine rotor. The turbine rotor has a rotor shaft that extends axially about the axis and a plurality of rows of rotor blades attached to the rotor shaft. The plurality of rows of rotor blades are aligned axially at intervals from one another. Each of the plurality of rows of rotor blades has a plurality of rotor blades aligned circumferentially about the axis.

[0003] The exhaust system defines an exhaust flow path through which exhaust gas, which is combustion gas that has passed through multiple blade rows of a turbine rotor, passes. As described in Patent Document 1 below, for example, the exhaust system includes a first outer diffuser, a second outer diffuser, an exhaust casing, an exhaust chamber, a first annular sealing device, and a second annular sealing device.

[0004] The first external diffuser is cylindrical about the axis and defines a radially outer edge of the upstream portion of the exhaust flowpath. This first external diffuser covers the outer periphery of an axially downstream portion of the turbine rotor where no blade rows are present. The exhaust casing is cylindrical about the axis and covers the outer periphery of the first external diffuser. The first external diffuser and the exhaust casing are both connected to the axially downstream end of the turbine casing. The second external diffuser is cylindrical about the axis and defines a radially outer edge of the downstream portion of the exhaust flowpath. The exhaust casing is cylindrical about the axis and covers the outer periphery of the second external diffuser. The second external diffuser is arranged at a distance downstream in the axial direction from the first external diffuser to allow for thermal elongation of the first external diffuser in the axial direction.

[0005] The first annular sealing device is provided from the axial downstream end of the first outer diffuser to the axial downstream end of the exhaust casing so as to suppress the inflow of exhaust gas between the first outer diffuser and the exhaust casing. That is, the first annular sealing device serves to seal between the exhaust flow path and a first outer space between the inner peripheral side of the exhaust casing and the outer peripheral side of the first outer diffuser. The second annular sealing device is provided from the axial upstream end of the second outer diffuser to the axial upstream end of the exhaust casing so as to suppress the inflow of exhaust gas between the second outer diffuser and the exhaust casing. That is, the second annular sealing device serves to seal between the exhaust flow path and a second outer space between the inner peripheral side of the exhaust casing and the outer peripheral side of the second outer diffuser. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2013 / 132692 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, the temperature of combustion gas has been increasing in order to improve gas turbine efficiency. This has increased the possibility of thermal damage to the first annular sealing device and the second annular sealing device. If the first annular sealing device were to be damaged, high-temperature exhaust gas would flow into the first outer space, significantly reducing the cooling effect of the air in the first outer space on the first outer diffuser, and there is a risk of thermal damage to the first outer diffuser as well.

[0008] Therefore, an object of the present disclosure is to provide exhaust equipment and a gas turbine equipped with the same that can suppress the inflow of exhaust gas between the inner circumferential side of the exhaust casing and the outer circumferential side of the first outer diffuser, or the inflow of exhaust gas between the inner circumferential side of the exhaust casing and the outer circumferential side of the first outer diffuser. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the invention is an exhaust system comprising: the turbine rotor is rotated by the first external diffuser and the second external diffuser is arranged at a distance from the first external diffuser on the downstream side of the axial direction of the axis, the second external diffuser being cylindrical about the axis and defining the radially outer edge of the downstream side of the exhaust flow passage through which exhaust gas that has rotated the turbine rotor passes; an exhaust casing having a cylindrical shape about the axis and covering an outer circumferential side of the first external diffuser; an exhaust chamber having a cylindrical shape about the axis and covering the outside of the second external diffuser; a first annular sealing device having an annular shape about the axis; a second annular sealing device having an annular shape about the axis; and a third annular sealing device having an annular shape about the axis. The exhaust casing includes a cylindrical exhaust casing body centered on the axis and an exhaust casing flange extending radially outward relative to the axis from an end of the exhaust casing body downstream of the axis. The exhaust chamber includes a cylindrical exhaust casing body centered on the axis and an exhaust casing flange extending radially outward from an end of the exhaust casing body upstream of the axis and connected to the exhaust casing flange. The first annular sealing device is provided on the first outer diffuser to suppress the exhaust gas from flowing into a first outer space between the first outer diffuser and the exhaust casing body. The second annular sealing device is provided on the second outer diffuser to suppress the exhaust gas from flowing into a second outer space between the second outer diffuser and the exhaust chamber body. The third annular sealing device is disposed between the first annular sealing device and the second annular sealing device in the axial direction. the third annular sealing device is provided at an end of the first outer diffuser on a downstream side in the axial direction so as to suppress the flow of the exhaust gas toward the first annular sealing device, or is provided at an end of the second outer diffuser on an upstream side in the axial direction so as to suppress the flow of the exhaust gas toward the second annular sealing device.

[0010] In this aspect, the first annular sealing device can suppress the inflow of exhaust gas into the first outer space, and the second annular sealing device can suppress the inflow of exhaust gas into the second outer space.

[0011] Furthermore, in this aspect, the third annular sealing device can suppress the flow of exhaust gas toward the first annular sealing device or the flow of exhaust gas toward the second annular sealing device. That is, in this aspect, the two sealing devices, the first annular sealing device and the third annular sealing device, can suppress the inflow of exhaust gas into the first outer space, or the two sealing devices, the second annular sealing device and the third annular sealing device, can suppress the inflow of exhaust gas into the second outer space.

[0012] If high-temperature exhaust gas were to flow into the first outer space, the cooling effect of the air present in the first outer space on the first outer diffuser would be significantly reduced, and the first outer diffuser could be thermally damaged.

[0013] In this aspect, even if the third annular sealing device is damaged by the heat of the exhaust gas, the first annular sealing device can prevent the exhaust gas from flowing into the first outer space. Therefore, in this aspect, thermal damage to the first outer diffuser caused by the flow of high-temperature exhaust gas into the first outer space can be prevented. Alternatively, for the same reason, in this aspect, thermal damage to the second outer diffuser caused by the flow of high-temperature exhaust gas into the second outer space can be prevented.

[0014] As a plant equipped with a gas turbine, there is a plant equipped with a heat recovery boiler that generates steam by utilizing the heat of exhaust gas discharged from the gas turbine. In this case, in this aspect, it is possible to suppress a decrease in the amount of exhaust gas supplied to the heat recovery boiler due to leakage of exhaust gas from the exhaust flow path.

[0015] In order to achieve the above object, a gas turbine according to one aspect of the invention comprises: One aspect of the present invention includes an exhaust system including an exhaust compressor capable of compressing air to generate compressed air, a combustor capable of burning fuel in the compressed air to generate combustion gas, and a turbine driven by the combustor. The turbine includes a turbine rotor rotatable about the axis and a turbine casing covering the outer periphery of the turbine rotor. The turbine rotor includes a rotor shaft extending in the axial direction about the axis, and a plurality of rotor blade rows attached to the rotor shaft and spaced apart in the axial direction. The turbine casing covers the outer periphery of the turbine rotor at a portion where the plurality of rotor blade rows are located. The exhaust casing of the exhaust system is connected to the axial downstream end of the turbine casing. [Effects of the Invention]

[0016] In the present disclosure, it is possible to suppress the inflow of exhaust gas between the inner circumferential side of the exhaust casing and the outer circumferential side of the first outer diffuser, or the inflow of exhaust gas between the inner circumferential side of the exhaust chamber and the outer circumferential side of the second outer diffuser. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cutaway side view of a main portion of a gas turbine in an embodiment according to the present disclosure. FIG. [Figure 2] 1 is a cross-sectional view of a main portion of a gas turbine in an embodiment according to the present disclosure. FIG. [Figure 3] FIG. 3 is an enlarged view of part III in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of part IV in FIG. [Figure 5] FIG. 4 is an enlarged view of a portion V in FIG. [Figure 6] 10A to 10C are explanatory diagrams illustrating a process of arranging spacers in one embodiment according to the present disclosure. [Figure 7] 10A to 10C are explanatory diagrams illustrating a process of arranging a spacer movement restrictor in one embodiment according to the present disclosure. [Figure 8] 10A and 10B are explanatory views showing the process of arranging a third seal assembly in one embodiment according to the present disclosure. [Figure 9] 10 is an explanatory diagram showing the arrangement and shape of a group of seal plates for each of a plurality of third seal assemblies in a comparative example. FIG. [Figure 10] 10 is an explanatory diagram showing the arrangement and shape of a group of seal plates for each of a plurality of third seal assemblies in one embodiment according to the present disclosure. FIG. [Figure 11] FIG. 10 is a perspective view of a spacer movement suppressor and a jig in a modified example according to the present disclosure. [Figure 12] FIG. 10 is a side view of a spacer movement suppressor according to a modified example of the present disclosure. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12. [Figure 14] 10A to 10C are explanatory diagrams showing a procedure (part 1) for attaching and removing a spacer movement suppressor in a modified example according to the present disclosure. [Figure 15] 15 is a cross-sectional view taken along line XV-XV in FIG. 14. [Figure 16] 10A and 10B are explanatory diagrams showing a second procedure for attaching a spacer movement suppressor in a modified example according to the present disclosure. [Figure 17] 17 is a cross-sectional view taken along line XVII-XVII in FIG. 16. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of a gas turbine according to the present invention will be described in detail with reference to FIGS.

[0019] As shown in FIG. 1, the gas turbine in this embodiment includes a compressor 10 capable of compressing outside air to generate compressed air, a combustor 2 capable of burning fuel from a fuel supply source in the compressed air to generate combustion gas, a turbine 20 capable of being driven by the combustion gas, and an exhaust facility 30.

[0020] The compressor 10 has a compressor rotor 11 that rotates about an axis Ar, a compressor casing 15 that covers the compressor rotor 11, and multiple stator vane rows 14. The turbine 20 has a turbine rotor 21 that rotates about the axis Ar, a turbine casing 25 that covers the turbine rotor 21, and multiple stator vane rows 24. Note that, hereinafter, the direction in which the axis Ar extends is referred to as the axial direction Da, the circumferential direction about the axis Ar is simply referred to as the circumferential direction Dc, and the direction perpendicular to the axis Ar is referred to as the radial direction Dr. One side of the axial direction Da is referred to as the axial upstream side Dau, and the opposite side is referred to as the axial downstream side Dad. The side of the radial direction Dr that approaches the axis Ar is referred to as the radially inner side Dri, and the opposite side is referred to as the radially outer side Dro.

[0021] The compressor 10 is disposed on the axial upstream side Dau with respect to the turbine 20 .

[0022] The compressor rotor 11 and the turbine rotor 21 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 1. For example, a rotor of a generator is connected to this gas turbine rotor 1. The gas turbine further includes an intermediate casing 6. This intermediate casing 6 is arranged between the compressor casing 15 and the turbine casing 25 in the axial direction Da. The combustor 2 is provided in this intermediate casing 6. The compressor casing 15, the intermediate casing 6, and the turbine casing 25 are connected to each other.

[0023] The compressor rotor 11 has a rotor shaft 12 that extends in an axial direction Da about an axis Ar, and a plurality of rotor blade rows 13 attached to the rotor shaft 12. The plurality of rotor blade rows 13 are aligned in the axial direction Da. Each rotor blade row 13 is made up of a plurality of rotor blades aligned in a circumferential direction Dc. One of the plurality of stator blade rows 14 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 13. Each stator blade row 14 is provided inside a compressor casing 15. Each stator blade row 14 is made up of a plurality of stator blades aligned in the circumferential direction Dc.

[0024] The turbine rotor 21 has a rotor shaft 22 extending in the axial direction Da centered on the axis Ar, and a plurality of rotor blade rows 23 attached to the rotor shaft 22. The plurality of rotor blade rows 23 are aligned in the axial direction Da. Each rotor blade row 23 is made up of a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 24 is arranged on the axial upstream side Dau of each of the plurality of rotor blade rows 23. Each stator blade row 24 is provided inside the turbine casing 25. Each stator blade row 24 is made up of a plurality of stator blades aligned in the circumferential direction Dc.

[0025] The annular space between the outer periphery of the rotor shaft 22 and the inner periphery of the turbine casing 25, in which the rotor blade row 23 and the stator blade row 24 are arranged in the axial direction Da, forms a combustion gas flow path through which the combustion gas from the combustor 2 flows.

[0026] The exhaust facility 30 is disposed on the axial downstream side Dad of the turbine casing 25. This exhaust facility 30 defines an exhaust flow path HP through which exhaust gas HG, which is combustion gas that has passed through the multiple rotor blade rows 23 of the turbine rotor 21, passes. This exhaust flow path HP is annular about the axis Ar and extends in the axial direction Da.

[0027] As shown in FIG. 2, the exhaust equipment 30 includes a first inner diffuser 31, a first outer diffuser 40, a second inner diffuser 32, a second outer diffuser 45, an exhaust casing 50, an exhaust chamber 60, a first annular sealing device 70a, a second annular sealing device 70b, and a third annular sealing device 80.

[0028] The first inner diffuser 31 is cylindrical and centered on the axis Ar, and defines the edge of the radially inner side Dri in the upstream portion of the exhaust flow path HP. This first inner diffuser 31 covers the outer periphery of the portion of the turbine rotor 21 on the axial downstream side Dad where the rotor blade rows 23 are not present. The first outer diffuser 40 is cylindrical and centered on the axis Ar, and defines the edge of the radially outer side Dro in the upstream portion of the exhaust flow path HP. Therefore, the first outer diffuser 40 is disposed on the outer periphery of the first inner diffuser 31. The exhaust casing 50 is cylindrical and centered on the axis Ar, and covers the outer periphery of the first outer diffuser 40. The exhaust casing 50 is connected to the end of the turbine casing 25 on the axial downstream side Dad. Furthermore, the first outer diffuser 40 is indirectly connected to the end of the turbine casing 25 on the axial downstream side Dad. A first outer space S1 into which cooling air can flow is formed between the inner peripheral side of the exhaust casing 50 and the outer peripheral side of the first outer diffuser 40.

[0029] A bearing 26 that rotatably supports a portion of the turbine rotor 21 on the axial downstream side Dad where no blade rows 23 are provided, and a bearing box 27 that covers the outer periphery of the bearing 26 and supports the bearing 26, are provided on the inner peripheral side of the first inner diffuser 31. The exhaust casing 50 and the bearing box 27 are connected by a plurality of struts 28 that penetrate the first outer diffuser 40 and the first inner diffuser 31. The struts 28 are aligned in the circumferential direction Dc at intervals from one another in the circumferential direction Dc. The exhaust gas HG flows between the struts 28. Each strut 28 is covered with a strut cover 29 along its extension direction. One end of the strut cover 29 in the extension direction is attached to the first outer diffuser 40, and the other end is attached to the first inner diffuser 31.

[0030] The second inner diffuser 32 is cylindrical and centered on the axis Ar, and defines the edge of the radially inner side Dri in the downstream portion of the exhaust flow path HP. The second inner diffuser 32 is disposed at a distance downstream from the first inner diffuser 31 in the axial direction Dad to allow for thermal elongation of the first inner diffuser 31 in the axial direction Da. A sealing device 33 is provided between the first inner diffuser 31 and the second inner diffuser 32 to prevent exhaust gas HG from leaking from the exhaust flow path HP through a gap therebetween. The second outer diffuser 45 is cylindrical and centered on the axis Ar, and defines the edge of the radially outer side Dro in the downstream portion of the exhaust flow path HP. For this reason, the second outer diffuser 45 is disposed on the outer peripheral side of the second inner diffuser 32. The second outer diffuser 45 is disposed at a distance from the first outer diffuser 40 on the axial downstream side Dad so as to allow for thermal elongation of the first outer diffuser 40 in the axial direction Da. The exhaust chamber 60 is cylindrical and centered on the axis Ar, and covers the outer peripheral side of the second outer diffuser 45. The end of the exhaust chamber 60 on the axial upstream side Dau is connected to the end of the exhaust casing 50 on the axial downstream side Dad. A second outer space S2 is formed between the inner peripheral side of the exhaust chamber 60 and the outer peripheral side of the second outer diffuser 45.

[0031] The first annular sealing device 70a, the second annular sealing device 70b, and the third annular sealing device 80 are all annular about the axis Ar.

[0032] The first annular sealing device 70a is provided from the end of the first outer diffuser 40 on the axial downstream side Dad to the end of the exhaust casing 50 on the axial downstream side Dad so as to suppress the inflow of exhaust gas HG into a first outer space S1 between the first outer diffuser 40 and the exhaust casing 50. That is, the first annular sealing device 70a serves to seal between the first outer space S1 and the exhaust flow path HP. The second annular sealing device 70b is provided from the end of the second outer diffuser 45 on the axial upstream side Dau to the end of the exhaust chamber 60 on the axial upstream side Dau so as to suppress the inflow of exhaust gas HG into a second outer space S2 between the second outer diffuser 45 and the exhaust chamber 60. That is, the second annular sealing device 70b serves to seal between the second outer space S2 and the exhaust flow path HP. The third annular sealing device 80 is disposed between the first annular sealing device 70a and the second annular sealing device 70b in the axial direction Da, and serves to suppress the flow of exhaust gas HG toward the first annular sealing device 70a.

[0033] As shown in FIGS. 3 and 5 , the exhaust casing 50 includes a cylindrical exhaust casing main body 51 centered on the axis Ar and an exhaust casing flange 52 extending radially outward from an end of the exhaust casing main body 51 on the axial downstream side Dad. The exhaust casing flange 52 includes a disc-shaped connecting portion 53 centered on the axis Ar and a recessed portion 55 that is also disc-shaped and centered on the axis Ar and connected to the inner periphery of the connecting portion 53. The connecting portion 53 has an exhaust casing contact surface 54 that faces the axial downstream side Dad and contacts the exhaust chamber 60. The recessed portion 55 has an exhaust casing flank 56 that is located radially inward Dri of the exhaust casing contact surface 54 and on the axial upstream side Dau. The exhaust casing flank 56 includes a first exhaust casing flank 56a and a second exhaust casing flank 56b that is located radially inward Dri of the first exhaust casing flank 56a and on the axial upstream side Dau.

[0034] 3 and 4, the first external diffuser 40 has a cylindrical first external diffuser body 41 centered on the axis Ar, and a first external diffuser end portion 42 provided at the end of the first external diffuser body 41 on the axial downstream side Dad. The first external diffuser end portion 42 has a first external diffuser end surface 43 located at the axially most downstream side Dad in the first external diffuser 40 and facing the axial downstream side Dad, and a seal receiving surface 44 located on the axial upstream side Dau and radially outward Dro of the first external diffuser end surface 43 and facing the axial downstream side Dad.

[0035] As shown in Figures 3 and 5, the exhaust chamber 60 includes a cylindrical exhaust chamber main body 61 centered on the axis Ar and an exhaust chamber flange 62 extending radially outward from an end of the exhaust chamber main body 61 on the axial upstream side Dau toward the radially outward side Dro. The exhaust chamber flange 62 includes a disc-shaped connecting portion 63 centered on the axis Ar and a recessed portion 65 that is also disc-shaped and centered on the axis Ar and connected to the inner periphery of the connecting portion 63. The connecting portion 63 has an exhaust chamber contact surface 64 that faces the axial upstream side Dau and comes into contact with the exhaust casing contact surface 54. The connecting portion 63 of the exhaust chamber flange 62 is connected to the connecting portion 53 of the exhaust casing flange 52 with a flange connecting bolt 69. The recessed portion 65 has an exhaust chamber flank surface 66 that is located radially inward Dri and downstream of the exhaust chamber contact surface 64 and faces the exhaust casing flank surface 56 at a distance in the axial direction Da. The exhaust chamber flank 66 has a first exhaust chamber flank 66a and a second exhaust chamber flank 66b located radially inward Dri and axially downstream Dad of the first exhaust chamber flank 66a.

[0036] 3 and 4, the second external diffuser 45 has a cylindrical second external diffuser body 46 centered on the axis Ar and a second external diffuser end portion 47 provided at the end of the second external diffuser body 46 on the axial upstream side Dau. The second external diffuser end portion 47 has a second external diffuser end surface 48 located at the axially most upstream side Dau of the second external diffuser 45 and facing the axial upstream side Dau, and a seal receiving surface 49 located downstream Dad and radially outward Dro of the second external diffuser end surface 48 and facing the axial upstream side Dau. As described above, the second external diffuser 45 is disposed at a distance from the first external diffuser 40 on the axial downstream side Dad. Therefore, a gap is formed between the first external diffuser end surface 43 and the second external diffuser end surface 48 in the axial direction Da.

[0037] The first annular seal device 70a has a plurality of first seal assemblies 71a arranged in the circumferential direction Dc, a plurality of first outer mounting fixtures 74a arranged in the circumferential direction Dc, and a plurality of first inner mounting fixtures 77a arranged in the circumferential direction Dc.

[0038] As shown in FIGS. 3 to 5, each of the first seal assemblies 71a includes a downstream seal plate group 72ad, an upstream seal plate group 72au, and a spacer 73a. The downstream seal plate group 72ad and the upstream seal plate group 72au are each a bundle of seal plates, each consisting of a plurality of seal plates extending in the radial direction Dr and the circumferential direction Dc, stacked in the axial direction Da. The downstream seal plate group 72ad is located axially downstream Dad of the upstream seal plate group 72au. The spacer 73a is disposed between the downstream seal plate group 72ad and the upstream seal plate group 72au in the axial direction Da to maintain a distance between the downstream seal plate group 72ad and the upstream seal plate group 72au in the axial direction Da. The radially outer portion Dro of the upstream seal plate group 72au of each of the first seal assemblies 71a contacts the second exhaust casing relief surface 56b of the exhaust casing flange 52. Furthermore, the radially inner portion Dri of the upstream seal plate group 72au of each of the plurality of first seal assemblies 71a contacts the seal receiving surface 44 of the first outer diffuser end portion 42.

[0039] The first outer mounting fixture 74a has a first outer pressing plate 75a that presses the radially outer portion Dro of the first seal assembly 71a against the second exhaust casing flank 56b of the exhaust casing flange 52, and a first outer mounting bolt 76a that attaches the first outer pressing plate 75a to the exhaust casing flange 52. The first outer pressing plate 75a contacts the radially outer portion Dro of the first seal assembly 71a and the first exhaust casing flank 56a of the exhaust casing flange 52. The radially outer portion Dro of the first seal assembly 71a is sandwiched between the first outer pressing plate 75a and the second exhaust casing flank 56b of the exhaust casing flange 52. The first outer mounting bolt 76a passes through the portion of the first outer pressing plate 75a that contacts the first exhaust casing flank 56a in the axial direction Da and is screwed into the exhaust casing flange 52. The first outer mounting bolt 76a does not penetrate the first seal assembly 71a in the axial direction Da. Therefore, the radially outer portion Dro of the first seal assembly 71a, which is sandwiched between the first outer pressing plate 75a and the second exhaust casing relief surface 56b of the exhaust casing flange 52, is movable in the radial direction Dr. Therefore, the first seal assembly 71a of this embodiment is allowed to thermally elongate in the radial direction Dr.

[0040] The first inner mounting fixture 77a has a first inner pressing plate 78a that presses the radially inner portion Dri of the first seal assembly 71a against the seal receiving surface 44 of the first outer diffuser end portion 42, and a first inner mounting bolt 79a that attaches the first inner pressing plate 78a to the first outer diffuser end portion 42. The first inner mounting bolt 79a passes through the first inner pressing plate 78a and the radially inner portion Dri of the first seal assembly 71a in the axial direction Da, and is screwed into the first outer diffuser end portion 42.

[0041] As described above, in this embodiment, the first outer pressing plate 75a is fixed to the exhaust casing flange 52 using the first outer mounting bolt 76a that penetrates in the axial direction Da through the portion of the first outer pressing plate 75a that contacts the first exhaust casing flank 56a. Furthermore, in this embodiment, the first inner pressing plate 78a and the radially inner portion Dri of the first seal assembly 71a are fixed to the first outer diffuser end portion 42 using the first inner mounting bolt 79a that penetrates in the axial direction Da through the first inner pressing plate 78a and the radially inner portion Dri of the first seal assembly 71a. Therefore, in this embodiment, when installing the first annular sealing device 70a, it is necessary to secure space that allows the first outer mounting bolt 76a and the first inner mounting bolt 79a to move in the axial direction Da. Therefore, in this embodiment, when installing the first annular sealing device 70a at a desired position and when removing the first annular sealing device 70a from the desired position, the exhaust chamber 60 is separated from the exhaust casing 50 to secure this space.

[0042] The second annular seal device 70b has a plurality of second seal assemblies 71b arranged in the circumferential direction Dc, a plurality of second outer mounting fixtures 74b arranged in the circumferential direction Dc, and a plurality of second inner mounting fixtures 77b arranged in the circumferential direction Dc.

[0043] Each of the second seal assemblies 71b includes a downstream seal plate group 72bd, an upstream seal plate group 72bu, and a spacer 73b. The downstream seal plate group 72bd and the upstream seal plate group 72bu are bundles of seal plates, each consisting of a plurality of seal plates extending in the radial direction Dr and the circumferential direction Dc, stacked in the axial direction Da. The downstream seal plate group 72bd is located axially downstream Dad of the upstream seal plate group 72bu. The spacer 73b is disposed between the downstream seal plate group 72bd and the upstream seal plate group 72bu in the axial direction Da to maintain a distance between the downstream seal plate group 72bd and the upstream seal plate group 72bu in the axial direction Da. The radially outer portion Dro of the downstream seal plate group 72bd of each of the second seal assemblies 71b contacts the second exhaust chamber relief surface 66b of the exhaust chamber flange 62. Furthermore, the radially inner portion Dri of the downstream seal plate group 72bd of each of the plurality of second seal assemblies 71b contacts the seal receiving surface 49 of the second outer diffuser end portion 47.

[0044] The second outer mounting fixture 74b includes a second outer pressing plate 75b that presses the radially outer portion Dro of the second seal assembly 71b against the second exhaust chamber flank 66b of the exhaust chamber flange 62, and a second outer mounting bolt 76b that attaches the second outer pressing plate 75b to the exhaust chamber flange 62. The second outer pressing plate 75b contacts the radially outer portion Dro of the second seal assembly 71b and the first exhaust chamber flank 66a of the exhaust chamber flange 62. The radially outer portion Dro of the second seal assembly 71b is sandwiched between the second outer pressing plate 75b and the second exhaust chamber flank 66b of the exhaust chamber flange 62. The second outer mounting bolt 76b penetrates the portion of the second outer pressing plate 75b that contacts the first exhaust chamber flank 66a and the exhaust chamber flange 62 in the axial direction Da. The second outer mounting bolt 76b does not penetrate the second seal assembly 71b in the axial direction Da. Therefore, the radially outer portion Dro of the second seal assembly 71b that is sandwiched between the second outer pressing plate 75b and the second exhaust chamber relief surface 66b of the exhaust chamber flange 62 is movable in the radial direction Dr. Therefore, the second seal assembly 71b of this embodiment is allowed to thermally elongate in the radial direction Dr.

[0045] The second inner mounting fixture 77b has a second inner pressing plate 78b that presses the radially inner portion Dri of the second seal assembly 71b against the seal receiving surface 49 of the second outer diffuser end portion 47, and a second inner mounting bolt 79b that attaches this second inner pressing plate 78b to the second outer diffuser end portion 47. The second inner mounting bolt 79b passes through the second inner pressing plate 78b and the radially inner portion Dri of the second seal assembly 71b in the axial direction Da, and is screwed into the second outer diffuser end portion 47.

[0046] As described above, in this embodiment, the second outer pressing plate 75b is fixed to the exhaust chamber flange 62 using the second outer mounting bolts 76b that penetrate in the axial direction Da through the portion of the second outer pressing plate 75b that contacts the first exhaust chamber flank surface 66a. Furthermore, in this embodiment, the second inner pressing plate 78b and the radially inner portion Dri of the second seal assembly 71b are fixed to the second outer diffuser end portion 47 using the second inner mounting bolts 79b that penetrate in the axial direction Da through the second inner pressing plate 78b and the radially inner portion Dri of the second seal assembly 71b. Therefore, in this embodiment, when installing the second annular sealing device 70b, it is necessary to ensure space in which the second outer mounting bolts 76b and the second inner mounting bolts 79b can be moved in the axial direction Da. Therefore, in this embodiment, when installing the second annular sealing device 70b at a desired position and when removing the second annular sealing device 70b from the desired position, the exhaust chamber 60 is separated from the exhaust casing 50 to ensure this space.

[0047] As shown in Figures 3 to 5, the third annular seal device 80 has a plurality of third seal assemblies 81 arranged in the circumferential direction Dc, a plurality of spacers 90 arranged in the circumferential direction Dc, and a plurality of spacer movement restraints 95 arranged in the circumferential direction Dc.

[0048] Each of the multiple third seal assemblies 81 includes a seal plate group 82, an outer frame 84 supporting an edge of the seal plate group 82 on the radially outer side Dro, an inner frame 85 supporting an edge of the seal plate group 82 on the radially inner side Dri, an outer pin 86 attaching the radially outer portion Dro of the seal plate group 82 to the outer frame 84, and an inner pin 87 attaching the radially inner portion Dri of the seal plate group 82 to the inner frame 85. The seal plate group 82 is a bundle of seal plates 83, each of which is formed by stacking multiple seal plates 83 extending in the radial direction Dr and the circumferential direction Dc in the axial direction Da. The outer pin 86 passes through the radially outer portion Dro of the seal plate group 82 and the outer frame 84, and is joined to the outer frame 84 by welding. The inner pin 87 passes through the radially outer portion Dro of the seal plate group 82 and the inner frame 85, and is joined to the inner frame 85 by welding. The outer frame 84 contacts the first outer pressing plate 75a from the axial downstream side Dad. The inner frame 85 contacts the first outer diffuser end face 43 and is joined to the first outer diffuser end face 43 by welding. Therefore, as shown in FIG. 4 , a weld 89 exists between the inner frame 85 and the first outer diffuser end face 43.

[0049] 5, the spacer 90 is disposed in a frame-flank space S3 between the outer frame 84 of the third seal assembly 81 and the exhaust chamber flank 66 of the exhaust chamber flange 62, and restricts movement of the outer frame 84 in the axial direction Da while allowing movement of the outer frame 84 in the radial direction Dr. Thus, the third seal assembly 81 of this embodiment is allowed to thermally elongate in the radial direction Dr. To be precise, the spacer 90 is disposed between the outer frame 84 of the third seal assembly 81 and the second outer pressing plate 75b, which is attached to the exhaust chamber flank 66 of the exhaust chamber flange 62 by the second outer mounting bolt 76b. The spacer 90 has an outer frame contact surface 91 that faces the axial upstream side Dau and contacts the outer frame 84, a frame-side recess 92 that is recessed from the outer frame contact surface 91 toward the axial downstream side Dad, a presser plate contact surface 93 that faces the axial downstream side Dad and contacts the second outer pressing plate 75b, and a presser plate-side recess 94 that is recessed from the presser plate contact surface 93 toward the axial upstream side Dau. The width in the axial direction Da between the outer frame contact surface 91 and the presser plate contact surface 93 of the spacer 90 substantially matches the distance in the axial direction Da between the outer frame 84 of the third seal assembly 81 and the second outer pressing plate 75b. Therefore, the outer frame 84 of the third seal assembly 81 is sandwiched between the first outer pressing plate 75a and the spacer 90, which is located axially upstream of the second outer pressing plate 75b, and movement in the axial direction Da is restricted. The bolt heads 76h of the second outer mounting bolts 76b that mount the second outer pressing plate 75b to the exhaust chamber relief surface 66 of the exhaust chamber flange 62 fit into the pressing plate side recesses 94 of the spacer 90.

[0050] As described above, the second outer pressing plate 75b is disposed between the frame and the clearance surface S3 as a second member that is immovable relative to the exhaust chamber 60. The spacer movement suppressor 95 increases the frictional force between the second outer pressing plate 75b and the spacer 90 to suppress movement of the spacer 90 in the radial direction Dr and the axial direction Da. The spacer movement suppressor 95 includes a spring 96 that generates elastic force in the axial direction Da, a spring support frame 97 that covers the end of the spring 96 on the upstream axial side Da and contacts the first outer pressing plate (first member) 75a, and a spring cover 98 that covers the end of the spring 96 on the downstream axial side Dad and contacts the spacer 90. The spring support frame 97 contacts the first outer pressing plate (first member) 75a from the downstream axial side Dad. The tip of the spring cover 98 fits into the frame-side recess 92 of the spacer 90 and contacts the bottom surface of the frame-side recess 92. Therefore, the spacer 90 is pressed toward the axial downstream side Dad by the spring 96 via the spring cover 98, increasing the frictional force between the spacer 90 and the second outer pressing plate (second member) 75b.

[0051] Next, the procedure for installing the above-described third annular seal device 80 will be described with reference to FIGS.

[0052] 6 , before the third annular sealing device 80 is attached, the exhaust casing flange 52 and the exhaust chamber flange 62 are connected by flange connecting bolts 69. The first annular sealing device 70a is provided from the end of the first outer diffuser 40 on the axial downstream side Dad to the end of the exhaust casing 50 on the axial downstream side Dad. The second annular sealing device 70b is provided from the end of the second outer diffuser 45 on the axial upstream side Dau to the end of the exhaust chamber 60 on the axial upstream side Dau.

[0053] First, the spacer 90 is placed between the first outer pressing plate 75a and the second outer pressing plate 75b. Furthermore, the spacer 90 is placed so that the bolt heads 76h of the second outer mounting bolts 76b that attach the second outer pressing plate 75b to the exhaust chamber flank 66 of the exhaust chamber flange 62 fit into the pressing plate-side recesses 94 of the spacer 90. In the process of placing the spacer 90, a jig 99a is used to move the spacer 90 from the radially inner sides Dri of the first outer diffuser 40 and the second outer diffuser 45, through between the first outer diffuser end face 43 and the second outer diffuser end face 48, and into between the first outer pressing plate 75a and the second outer pressing plate 75b.

[0054] If the bolt heads 76h of the second outer mounting bolts 76b are simply inserted into the presser plate-side recesses 94 of the spacer 90, there is a high possibility that the spacer 90 will fall. For this reason, as shown in FIG. 7, a spacer movement suppressor 95 is disposed between the spacer 90 and the first outer presser plate 75a. Furthermore, as shown in FIG. 5, the spacer movement suppressor 95 is disposed so that the spring support frame 97 of the spacer movement suppressor 95 contacts the first outer presser plate 75a and the tip end portion of the spring cover 98 of the spacer movement suppressor 95 enters the frame-side recess 92 of the spacer 90 and contacts the bottom surface of this frame-side recess 92. In the process of disposing the spacer movement suppressor 95, a jig 99b is used to move the spacer movement suppressor 95 from the radially inner side Dri of the first outer diffuser 40 and the second outer diffuser 45, through the gap between the first outer diffuser end face 43 and the second outer diffuser end face 48, and into the gap between the spacer 90 and the first outer presser plate 75a. The arrangement of this spacer movement suppressor 95 increases the frictional force between the second outer pressing plate 75b and the spacer 90, suppressing movement of the spacer 90 in the radial direction Dr and the axial direction Da, thereby preventing the spacer 90 from falling off.

[0055] One method for restricting movement of the spacer 90 in the radial direction Dr and the axial direction Da is to use a bolt that penetrates the spacer 90 in the axial direction Da. When this method is employed, the bolt cannot be moved in the axial direction Da within the frame-flank distance S3 when the exhaust casing contact surface 54 of the exhaust casing flange 52 and the exhaust chamber contact surface 64 of the exhaust chamber flange 62 are in contact with each other. Therefore, when this method is employed, the exhaust chamber 60 must be spaced apart from the exhaust casing 50. However, in this embodiment, instead of using a bolt, the spacer movement restrictor 95 is used to increase the frictional force between the spacer 90 and the second outer pressing plate 75b, thereby restricting movement of the spacer 90 in the radial direction Dr and the axial direction Da. Therefore, the spacer 90 and the spacer movement restrictor 95 can be disposed even when the exhaust casing 60 is connected to the exhaust casing 50.

[0056] 8 and 3, the third seal assembly 81 is positioned so that the outer frame 84 of the third seal assembly 81 is located between the first outer pressing plate 75a and the spacer 90 and the inner frame 85 of the third seal assembly 81 faces the first outer diffuser end face 43. In the process of positioning the third seal assembly 81, the third seal assembly 81 is moved from the radially inner side Dri of the first outer diffuser 40 and the second outer diffuser 45, through between the first outer diffuser end face 43 and the second outer diffuser end face 48, to the radially outer side Dro so that the outer frame 84 of the third seal assembly 81 reaches between the spacer 90 and the first outer pressing plate 75a.

[0057] 9, when the seal plate groups 82c of a plurality of third seal assemblies 81c are arranged in the circumferential direction Dc to form an annular seal plate array SR centered on the axis Ar, the length in the circumferential direction Dc of the outer edge of the annular seal plate array SR is longer than the length in the circumferential direction Dc of the inner edge of the annular seal plate array SR. Therefore, suppose that for all of the seal plate groups 82c of each of the plurality of third seal assemblies 81c, the length in the circumferential direction Dc of the outer edge of the seal plate group 82c is made longer than the length in the circumferential direction Dc of the inner edge of the annular seal plate group 82c.

[0058] In this case, as described above, even if an attempt is made to sequentially arrange multiple third seal assemblies 81c, it is not possible to arrange the last third seal assembly 81c at the desired position by moving the last third seal assembly 81c radially outward Dro. This is because, based on the intended arrangement position Pr at which the last third seal assembly 81c of the multiple third seal assemblies 81c already arranged is to be arranged, the distance d1 in the circumferential direction Dc between the inner edge of the seal plate group 82c in the third seal assembly 81c arranged on one side in the circumferential direction Dc and the inner edge of the seal plate group 81c in the third seal assembly 81c arranged on the other side in the circumferential direction Dc is smaller than the dimension d2 in the circumferential direction Dc of the outer edge of the seal plate group 81c in the last third seal assembly 81c.

[0059] Therefore, in order to sequentially move the plurality of third seal assemblies 81 radially outward Dro and position all of the plurality of third seal assemblies 81 at their target positions, the length of the circumferential direction Dc of the outer edge of each seal plate 83 constituting the seal plate group 82 of at least some of the third seal assemblies 81 needs to be the same as the length of the circumferential direction Dc of the inner edge of each seal plate 83. In this case, the length of the circumferential direction Dc of each seal plate 83 constituting the seal plate group 82 of the other third seal assemblies 81 of the plurality of third seal assemblies 81, excluding at least some of the third seal assemblies 81, is longer than the length of the circumferential direction Dc of the inner edge of each seal plate 83.

[0060] 10 , of the plurality of third seal assemblies 81, each of the seal plates 83b constituting the seal plate group 82b of a portion of the plurality of third seal assemblies 81b has the same outer edge length Dc as the inner edge length Dc. Furthermore, of the plurality of third seal assemblies 81, each of the seal plates 83a constituting the seal plate group 82a of the remaining portion of the plurality of third seal assemblies 81a has an outer edge length Dc longer than the inner edge length Dc. Therefore, in this embodiment, all of the third seal assemblies 81 can be sequentially moved radially outward Dro, thereby positioning all of the third seal assemblies 81 at their desired positions.

[0061] After the placement of the third seal assembly 81 is completed, the inner frame 85 of the third seal assembly 81 is joined to the first outer diffuser end face 43 by welding, as described above with reference to FIG.

[0062] One method for restricting relative movement of the inner frame 85 of the third seal assembly 81 with respect to the end of the first outer diffuser 40 is to use bolts that penetrate the inner frame 85 in the axial direction Da. When this method is used, the bolts cannot be moved in the axial direction Da when the exhaust casing contact surface 54 of the exhaust casing flange 52 and the exhaust casing contact surface 64 of the exhaust casing flange 62 are in contact with each other. For this reason, when this method is used, the exhaust casing 60 needs to be separated from the exhaust casing 50. However, in the present embodiment, the inner frame 85 is fixed to the end of the first outer diffuser 40 by welding without using bolts. Therefore, the inner frame 85 can be fixed to the end of the first outer diffuser 40 even when the exhaust casing 60 is connected to the exhaust casing 50.

[0063] This completes the installation of the third annular seal device 80.

[0064] As described above, in this embodiment, the first annular sealing device 70a can suppress the inflow of exhaust gas HG into the first outer space S1, and the second annular sealing device 70b can suppress the inflow of exhaust gas HG into the second outer space S2.

[0065] Furthermore, in this embodiment, the flow of the exhaust gas HG toward the first annular sealing device 70a can be suppressed by the third annular sealing device 80. That is, in this embodiment, the two sealing devices, the first annular sealing device 70a and the third annular sealing device 80, can suppress the inflow of the exhaust gas HG into the first outer space S1.

[0066] If high-temperature exhaust gas HG flows into the first outer space S1, the cooling effect of the air present in the first outer space S1 on the first outer diffuser 40 will be significantly reduced, and there is a risk that the first outer diffuser 40 will be thermally damaged.

[0067] In the present embodiment, even if the third annular sealing device 80 is damaged by the heat of the exhaust gas HG, the first annular sealing device 70a can suppress the inflow of the exhaust gas HG into the first outer space S1. Therefore, in this aspect, it is possible to suppress thermal damage to the first outer diffuser 40 caused by the inflow of the high-temperature exhaust gas HG into the first outer space S1.

[0068] As a plant equipped with a gas turbine, there is a plant equipped with a heat recovery boiler that generates steam by utilizing the heat of exhaust gas HG exhausted from the gas turbine. In this case, in this embodiment, it is possible to suppress a decrease in the supply amount of exhaust gas HG to the heat recovery boiler due to leakage of the exhaust gas HG from the exhaust passage HP.

[0069] Furthermore, in the present embodiment, each component constituting the third annular sealing device 80 can be moved from the radially inner side Dri of the first outer diffuser 40 and the second outer diffuser 45 to the radially outer side Dro, via between the first outer diffuser end face 43 and the second outer diffuser end face 48, so that each component constituting the third annular sealing device 80 can be disposed at a desired position. Therefore, in the present embodiment, even in a state in which the exhaust chamber 60 is connected to the exhaust casing 50, the third annular sealing device 80 can be attached to a desired position and can also be removed from the desired position.

[0070] "Modified example of spacer movement suppressor" As shown in FIGS. 11 to 13, a spacer movement suppressor 100 in this modification also has a spring 96, a spring support frame 101, and a spring cover 105, similar to the spacer movement suppressor 95 in the above embodiment.

[0071] The spring support frame 101 in this modified example has a frame main body 102 that covers the end of the spring 96 on the axial upstream side Dau, and a frame flange 103. The frame main body 102 has a member contact surface 102p that comes into contact with the outer pressing plate 75a, which is the first member. The frame flange 103 is located on the axial downstream side Dad of the member contact surface 102p, and protrudes from the frame main body 102 in the circumferential direction Dc.

[0072] The spring cover 105 has a cover main body 106 that covers the end of the spring 96 on the axial downstream side Dad, and a cover flange 107. The cover main body 106 has a spacer contact surface 106p that comes into contact with the spacer 90. The cover flange 107 is located on the axial upstream side Dau of the spacer contact surface 106p and protrudes from the cover main body 106 in the circumferential direction Dc. The cover flange 107 faces the frame flange 103 with a gap in the axial direction Da.

[0073] When the spacer movement suppressing device 100 of this modified example is arranged between the spacer 90 and the first outer pressing plate 75a, a jig 110 is used. The jig 110 has a clamping jig 111 and a pressing bar 115.

[0074] The clamping jig 111 has a finger support rod 112 and a first finger 113 and a second finger 114 provided at the tip of the finger support rod 112. A hole 112h is formed in the finger support rod 112 at the position of the central axis Ac of the finger support rod 112, in the central axis direction Dac along which the central axis Ac of the finger support rod 112 extends. The first finger 113 and the second finger 114 extend in either central axis direction Dac. The first finger 113 and the second finger 114 face each other with a gap in the radial direction relative to the central axis Ac. A first tapered surface 113t is formed at the tip of the first finger 113. This first tapered surface 113t is inclined with respect to the central axis direction Dac so that it gradually moves away from the second finger 114 as it moves away from the finger support rod 112 in the central axis direction Dac. A second tapered surface 114t is formed at the tip of the second finger 114. This second tapered surface 114t is inclined with respect to the central axis direction Dac so as to gradually move away from the first finger 113 as it moves away from the finger support bar 112 in the central axis direction Dac.

[0075] The pressing bar 115 is a bar that can be inserted into a hole 112 h formed in the finger support bar 112 of the clamping jig 111 .

[0076] Next, the procedure for installing the spacer movement suppressor 100 using the jig 110 will be described with reference to FIGS. 14 and 15. First, the spring 96 is placed between the spring support frame 101 and the spring cover 105, and the spring 96 is covered by the spring support frame 101 and the spring cover 105. Next, the frame flange 103 of the spring support frame 101 and the cover flange 107 of the spring cover 105 are inserted between the first finger 113 and the second finger 114 of the clamping jig 111, thereby narrowing the gap between the frame flange 103 and the cover flange 107. As a result, the gap between the member contact surface 102p of the spring support frame 101 and the spacer contact surface 106p of the spring cover 105 is narrowed. Then, the clamping jig 111 is operated to insert the spacer movement suppressor 100 attached to the clamping jig 111 between the spacer 90 and the first outer pressing plate 75a.

[0077] 16 and 17, the spacer movement suppressor 100 is inserted between the spacer 90 and the first outer pressing plate 75a, and then the pressure rod 115 is protruded radially outward (Dro) through the hole 112h of the finger support rod 112, while the clamping jig 111 is pulled radially inward (Dri). As a result, the spacer movement suppressor 100 is supported by the pressure rod 115, and the frame flange 103 and the cover flange 107 are released from between the first finger 113 and the second finger 114 of the clamping jig 111 without changing the position of the spacer movement suppressor 100 in the radial direction (Dr). Then, the spring 96 of the spacer movement suppressor 100 widens the gap between the frame flange 103 and the cover flange 107, and the gap between the member contact surface 102p of the spring support frame 101 and the spacer contact surface 106p of the spring cover 105. Then, the member contact surface 102p of the spring support frame 101 comes into close contact with the outer pressing plate 75a, and the spacer contact surface 106p of the spring cover 105 comes into close contact with the spacer 90.

[0078] This completes the installation of the spacer movement suppressor 100.

[0079] Next, the procedure for removing the spacer movement suppressor 100 using the jig 110 will be described again with reference to Figures 14 and 15. A clamping jig 111 is attached to the spacer movement suppressor 100, which is positioned between the spacer 90 and the first outer pressing plate 75a. At this time, the clamping jig 111 is moved radially outward Dro so that the first finger 113 and the second finger 114 of the clamping jig 111 reach between the spacer 90 and the first outer pressing plate 75a. During this operation, the frame flange 103 comes into contact with the first tapered surface 113t of the first finger 113, and the cover flange 107 comes into contact with the second tapered surface 114t of the second finger 114. When the clamping jig 111 is operated radially outward Dro, the frame flange 103 in contact with the first tapered surface 113t of the first finger 113 is pushed by the first tapered surface 113t and gradually moves toward the cover flange 107 (axial downstream side Dad). Furthermore, the cover flange 107 in contact with the second tapered surface 114t of the second finger 114 is pushed by the second tapered surface 114t and gradually moves toward the spring support frame 101 (axial upstream side Dau). In other words, the distance between the frame flange 103 and the cover flange 107 and the distance between the member contact surface 102p of the spring support frame 101 and the spacer contact surface 106p of the spring cover 105 gradually narrow.

[0080] When the frame flange 103 of the spring support frame 101 and the cover flange 107 of the spring cover 105 are completely inserted between the first finger 113 and the second finger 114 of the clamping jig 111, the spacer contact surface 106p of the cover flange 107 is completely separated from the spacer 90. Then, by operating the finger support rod 112, the spacer movement suppressing device 100 attached to this clamping jig 111 is pulled out radially inward Dri from between the spacer 90 and the first outer pressing plate 75a.

[0081] This completes the removal of the spacer movement suppressor 100.

[0082] As described above, by using the spacer movement suppressing device 100 and the jig 110 in this modified example, the spacer movement suppressing device 100 can be easily placed and removed.

[0083] "Other Modifications" In the above embodiment, after the spacer 90 is placed between the first outer pressing plate 75a and the second outer pressing plate 75b, the outer frame 84 of the third seal assembly 81 is positioned between the spacer 90 and the first outer pressing plate 75a, and the inner frame 85 of the third seal assembly 81 is welded to the first outer diffuser end 42. During this period, however, the spacer movement restraint device 95, 100 is used to restrain the spacer 90 from moving. However, if the work is carried out carefully to prevent the spacer 90 from moving during this period, or if the spacer 90 is held down with a jig during this period, the spacer movement restraint device 95 may not be necessary.

[0084] Furthermore, in the above embodiment, the third annular sealing device 80 is provided at the end of the first outer diffuser 40 on the downstream side Dad in the axial direction so as to suppress the flow of the exhaust gas HG toward the first annular sealing device 70a. However, the third annular sealing device 80 may be provided at the end of the second outer diffuser 45 on the upstream side Dau in the axial direction so as to suppress the flow of the exhaust gas HG toward the second outer space S2. In this case, the two sealing devices, the second annular sealing device 70b and the third annular sealing device 80, can suppress the inflow of the exhaust gas HG into the second outer space S2. Therefore, in this case, thermal damage to the second outer diffuser 45 caused by the inflow of high-temperature exhaust gas HG into the second outer space S2 can be suppressed.

[0085] Furthermore, the present disclosure is not limited to the embodiment and modifications described above, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention derived from the content defined in the claims and their equivalents.

[0086] "Addendum" The exhaust equipment in the above-described embodiment and modified examples can be understood, for example, as follows. (1) The exhaust equipment in the first aspect is a first external diffuser 40 that is cylindrical about the axis Ar and that defines an edge of a radially outer side Dro in an upstream portion of an exhaust flow path HP through which exhaust gas HG that has rotated the turbine rotor 21 passes; and a second external diffuser 41 that is arranged with a gap on the axial downstream side Dad of the axial upstream side Dau and the axial downstream side Dad in an axial direction Da in which the axis Ar extends, and that is cylindrical about the axis Ar and through which exhaust gas HG that has passed through the first external diffuser 40 passes. The exhaust casing 50 includes a second external diffuser 45 that defines an edge of the radially outer side Dro in the downstream portion of P, an exhaust casing 50 that is cylindrical about the axis Ar and covers the outer periphery of the first external diffuser 40, an exhaust chamber 60 that is cylindrical about the axis Ar and covers the outside of the second external diffuser 45, a first annular sealing device 70a that is annular about the axis Ar, a second annular sealing device 70b that is annular about the axis Ar, and a third annular sealing device 80 that is annular about the axis Ar. The exhaust casing 50 includes an exhaust casing main body 51 that is cylindrical about the axis Ar, and an exhaust casing flange 52 that extends from an end of the exhaust casing main body 51 on the axial downstream side Dad to the radially outer side Dro relative to the axis Ar. The exhaust chamber 60 includes a cylindrical exhaust chamber main body 61 centered on the axis Ar, and an exhaust chamber flange 62 extending from an end of the exhaust chamber main body 61 on the upstream side of the axis Dau to the radially outer side Dro and connected to the exhaust casing flange 52. The first annular sealing device 70a is provided in the first outer diffuser 40 to suppress the exhaust gas HG from flowing into a first outer space S1 between the first outer diffuser 40 and the exhaust casing main body 51. The second annular sealing device 70b is provided in the second outer diffuser 45 to suppress the exhaust gas HG from flowing into a second outer space S2 between the second outer diffuser 45 and the exhaust chamber main body 61. The third annular sealing device 80 is disposed between the first annular sealing device 70a and the second annular sealing device 70b in the axial direction Da.The third annular sealing device 80 is provided at the axial downstream end Dad of the first outer diffuser 40 so as to suppress the flow of the exhaust gas HG toward the first annular sealing device 70a, or is provided at the axial upstream end Dau of the second outer diffuser 45 so as to suppress the flow of the exhaust gas HG toward the second annular sealing device 70b.

[0087] In this embodiment, the first annular sealing device 70a can suppress the exhaust gas HG from flowing into the first outer space S1, and the second annular sealing device 70b can suppress the exhaust gas HG from flowing into the second outer space S2.

[0088] Furthermore, in this embodiment, the third annular sealing device 80 can suppress the flow of exhaust gas HG toward the first annular sealing device 70a or the flow of exhaust gas HG toward the second annular sealing device 70b. That is, in this embodiment, the two sealing devices, the first annular sealing device 70a and the third annular sealing device 80, can suppress the inflow of exhaust gas HG into the first outer space S1, or the two sealing devices, the second annular sealing device 70b and the third annular sealing device 80, can suppress the inflow of exhaust gas HG into the second outer space S2.

[0089] If high-temperature exhaust gas HG flows into the first outer space S1, the cooling effect of the air present in the first outer space S1 on the first outer diffuser 40 will be significantly reduced, and there is a risk that the first outer diffuser 40 will be thermally damaged.

[0090] In this embodiment, even if the third annular sealing device 80 is damaged by the heat of the exhaust gas HG, the first annular sealing device 70a can prevent the exhaust gas HG from flowing into the first outer space S1. Therefore, in this embodiment, it is possible to prevent thermal damage to the first outer diffuser 40 caused by the flow of the high-temperature exhaust gas HG into the first outer space S1. Alternatively, for the same reason, it is possible to prevent thermal damage to the second outer diffuser 45 caused by the flow of the high-temperature exhaust gas HG into the second outer space S2.

[0091] As a plant equipped with a gas turbine, there is a plant equipped with a heat recovery boiler that generates steam by utilizing the heat of exhaust gas HG exhausted from the gas turbine. In this case, in this embodiment, it is possible to suppress a decrease in the supply amount of exhaust gas HG to the heat recovery boiler due to leakage of the exhaust gas HG from the exhaust passage HP.

[0092] (2) The exhaust equipment in the second aspect is In the exhaust equipment 30 of the first aspect, the third annular seal device 80 has a plurality of third seal assemblies 81 arranged in a circumferential direction Dc relative to the axis Ar. Each of the plurality of third seal assemblies 81 has a seal plate 83 extending in a radial direction Dr relative to the axis Ar and in the circumferential direction Dc, an inner frame 85 supporting an edge of the seal plate 83 on a radially inner side Dri relative to the axis Ar, and an outer frame 84 supporting an edge of the seal plate 83 on a radially outer side Dro.

[0093] (3) The exhaust equipment in the third aspect is In the exhaust equipment 30 of the second aspect, the third annular sealing device 80 is provided at an end of the second outer diffuser 45 on the axial upstream side Dau so as to suppress the flow of the exhaust gas HG toward the second annular sealing device 70b. The exhaust casing flange 52 has a connection portion 53 having an exhaust casing contact surface 54 that contacts the exhaust casing flange 62, and a relief portion 55 having an exhaust casing flank 56 located radially inward Dri of the exhaust casing contact surface 54 and on the axial upstream side Dau. The exhaust casing flange 62 has a connection portion 63 having an exhaust casing contact surface 64 that contacts the exhaust casing contact surface 54, and a relief portion 65 having an exhaust casing flank 66 located radially inward Dri of the exhaust casing contact surface 64 and on the axial downstream side Dad, facing the exhaust casing flank 56 at a distance in the axial direction Da. The outer frame 84 of each of the plurality of third seal assemblies 81 is disposed between the exhaust casing clearance surface 56 and the exhaust chamber clearance surface 66 so as to be movable in the radial direction Dr.

[0094] In this embodiment, thermal expansion of the third seal assembly 81 in the radial direction Dr can be permitted.

[0095] (4) The exhaust equipment in the fourth aspect is In the exhaust equipment 30 of the third embodiment, the third annular seal device 80 is arranged in a frame-flush space S3 between the outer frame 84 of each of the plurality of third seal assemblies 81 and the exhaust chamber flap 66, and has a spacer 90 that restricts movement of the outer frame 84 of each of the plurality of third seal assemblies 81 in the axial direction Da while allowing movement of the outer frame 84 in the radial direction Dr.

[0096] In this embodiment, movement of the outer frame 84 in the radial direction Dr is permitted, while movement of the outer frame 84 in the axial direction Da can be restricted.

[0097] (5) The exhaust equipment in the fifth aspect is In the exhaust equipment 30 of the fourth aspect, the second annular sealing device 70b has a second member 75b that is disposed in the frame-flank space S3 and is immovable relative to the exhaust chamber 60. The third annular sealing device 80 has spacer movement suppressors 95, 100 that increase the frictional force between the spacer 90 and the second member 75b and suppress movement of the spacer 90 in the radial direction Dr and the axial direction Da.

[0098] In this embodiment, the spacer movement suppressing devices 95, 100 can suppress movement of the spacer 90 in the radial direction Dr and the axial direction Da, and therefore can suppress movement of the spacer 90 from the frame-flank surface gap S3.

[0099] One method for suppressing movement of the spacer 90 in the radial direction Dr and the axial direction Da is to use a bolt that penetrates the spacer 90 in the axial direction Da. When this method is employed, the bolt cannot be moved in the axial direction Da within the frame-flank distance S3 when the exhaust casing contact surface 54 of the exhaust casing flange 52 and the exhaust chamber contact surface 64 of the exhaust chamber flange 62 are in contact with each other. For this reason, when this method is employed, the exhaust chamber 60 must be spaced apart from the exhaust casing 50. However, in this embodiment, bolts are not used, and the spacer movement suppressors 95, 100 are used to increase the frictional force between the spacer 90 and the components and suppress movement of the spacer 90 in the radial direction Dr and the axial direction Da. Therefore, the spacer 90 and the spacer movement suppressors 95, 100 can be disposed even when the exhaust casing 60 is connected to the exhaust casing 50.

[0100] (6) The exhaust equipment in the sixth aspect is In the exhaust equipment 30 of the fifth aspect, the first annular sealing device 70a faces the spacer 90 at an interval in the axial direction Da and has a first member 75a that is provided so as to be immovable relative to the exhaust casing 50. The spacer movement suppressing device 95, 100 has a spring 96 that generates an elastic force in the axial direction Da, a spring support frame 97, 101 that covers an end of one side Dau of the spring 96 in the axial direction Da and comes into contact with the first member 75a, and a spring cover 98, 105 that covers an end of the other side Dad of the spring 96 in the axial direction Da and comes into contact with the spacer 90.

[0101] (7) The exhaust equipment in the seventh aspect is In the exhaust equipment 30 of the sixth aspect, the spring support frame 101 includes a frame main body 102 that covers an end of the spring 96 on the one side Dau in the axial direction Da, and a frame flange 103. The frame main body 102 has a member contact surface 102p that contacts the first member 75a. The frame flange 103 is located closer to the other side Dad in the axial direction Da than the member contact surface 102p and protrudes from the frame main body 102 in the circumferential direction Dc. The spring cover 105 includes a cover main body 106 that covers an end of the spring 96 on the other side Dad in the axial direction Da, and a cover flange 107. The cover main body 106 has a spacer contact surface 106p that contacts the spacer 90. The cover flange 107 is located on the one side Dau in the axial direction Da relative to the spacer contact surface 106p, and protrudes in the circumferential direction Dc from the cover main body 106. The cover flange 107 faces the frame flange 103 in the axial direction Da with a gap therebetween.

[0102] In this embodiment, the jig 110 is used to narrow the gap between the frame flange 103 and the cover flange 107, thereby narrowing the gap between the member contact surface 102p of the spring support frame 101 and the spacer contact surface 106p of the spring cover 105, thereby making it easy to install and remove the spacer movement inhibitor 100.

[0103] (8) In the eighth aspect, the exhaust equipment is In the exhaust equipment 30 according to the sixth or seventh aspect, the spacer 90 is formed with a recess 92 that is recessed in the axial direction Da and into which a part of the spring cover 98, 105 fits.

[0104] In this embodiment, parts of the spring covers 98, 105 of the spacer movement suppressors 95, 100 fit into the recesses 92 of the spacer 90, thereby suppressing relative movement of the spacer 90 with respect to the spacer movement suppressors 95, 100 in the radial direction Dr and the circumferential direction Dc.

[0105] (9) In the ninth aspect, the exhaust equipment is In the exhaust equipment 30 according to any one of the third to eighth embodiments, the inner frame 85 of each of the plurality of third seal assemblies 81 is fixed by welding to the end Dad of the first outer diffuser 40 on the downstream side of the axis.

[0106] One method for restricting relative movement of the inner frame 85 of the third seal assembly 81 with respect to the end of the first outer diffuser 40 is to use bolts that penetrate the inner frame 85 in the axial direction Da. When this method is employed, the bolts cannot be moved in the axial direction Da when the exhaust casing contact surface 54 of the exhaust casing flange 52 and the exhaust casing contact surface 64 of the exhaust casing flange 62 are in contact with each other. For this reason, when this method is employed, the exhaust casing 60 needs to be separated from the exhaust casing 50. However, in this embodiment, the inner frame 85 is fixed to the end of the first outer diffuser 40 by welding without using bolts. Therefore, the inner frame 85 can be fixed to the end of the first outer diffuser 40 even when the exhaust casing 60 is connected to the exhaust casing 50.

[0107] (10) In a tenth aspect, the exhaust equipment comprises: In the exhaust equipment 30 according to any one of the second to ninth aspects, the seal plate 83b of at least one third seal assembly 81 among the plurality of third seal assemblies 81 has the same length in the circumferential direction Dc of the edge of the radially outer side Dro and the same length in the circumferential direction Dc of the edge of the radially inner side Dri. The seal plates 83a of the other third seal assemblies 81 among the plurality of third seal assemblies 81, excluding the at least one third seal assembly 81, have a length in the circumferential direction Dc of the edge of the radially outer side Dro that is longer than the length in the circumferential direction Dc of the edge of the radially inner side Dri.

[0108] In this embodiment, even when the exhaust chamber 60 is connected to the exhaust casing 50, all of the third seal assemblies 81 can be moved from the radially inner side Dri of the first outer diffuser 40 and the second outer diffuser 45 to the radially outer side Dro, and all of the third seal assemblies 81 can be positioned at the desired positions.

[0109] The gas turbines in the above-described embodiments and modifications can be understood, for example, as follows. (11) In an eleventh aspect, the gas turbine comprises: The exhaust equipment (30) according to any one of the first to tenth aspects includes a compressor (10) capable of compressing air to generate compressed air, a combustor (2) capable of burning fuel in the compressed air to generate combustion gas, and a turbine (20) capable of being driven by the combustion gas from the combustor (2). The turbine (20) includes a turbine rotor (21) rotatable about the axis Ar and a turbine casing (25) covering an outer periphery of the turbine rotor (21). The turbine rotor (21) includes a rotor shaft (22) extending in the axial direction Da about the axis Ar, and a plurality of moving blade rows (23) attached to the rotor shaft (22) and aligned in the axial direction Da at intervals in the axial direction Da. The turbine casing (25) covers the outer periphery of a portion of the turbine rotor (21) where the plurality of moving blade rows (23) are present. The exhaust casing (50) of the exhaust equipment (30) is connected to an end (Dad) of the turbine casing (25) on the axial downstream side. [Explanation of symbols]

[0110] 1: Gas turbine rotor 2: Combustor 6: Intermediate car compartment 10: Compressor 11: Compressor rotor 12: Rotor shaft 13: Moving blade row 14: Stator blade row 15: Compressor compartment 20: Turbine 21: Turbine rotor 22: Rotor shaft 23: Moving blade row 24: Stator blade row 25: Turbine compartment 26: Bearing 27: Bearing box 28: Strut 29: Strut cover 30: Exhaust equipment 31: First inner diffuser 32: Second inner diffuser 33: Sealing device 40: First outer diffuser 41: First outer diffuser body 42: First outer diffuser end 43: First outer diffuser end face 44: Seal receiving surface 45: Second outer diffuser 46: Second outer diffuser body 47: Second outer diffuser end 48: Second outer diffuser end face 49: Seal receiving surface 50: Exhaust compartment 51: Exhaust compartment body 52: Exhaust casing flange 53: Connection 54: Exhaust casing contact surface 55: Escape 56: Exhaust casing flank 56a: First exhaust casing relief surface 56b: Second exhaust casing relief 60: Exhaust chamber 61: Exhaust chamber body 62: Exhaust chamber flange 63: Connection 64: Exhaust chamber contact surface 65: Escape 66: Exhaust chamber relief 66a: First exhaust chamber relief surface 66b: Second exhaust chamber relief surface 69: Flange connection bolt 70a: First annular seal device 71a: First seal assembly 72ad: Downstream seal plate group 72au: Upstream seal plate group 73a: Spacer 74a: First outer fitting 75a: First outer pressing plate (or first member) 76a: First outer mounting bolt 77a: First inner fixture 78a: First inner pressing plate 79a: First inner mounting bolt 70b: Second annular seal device 71b: Second seal assembly 72bd: Downstream seal plate group 72bu: Upstream seal plate group 73b: Spacer 74b: Second outer mounting fixture 75b: Second outer pressing plate (or second member) 76b: Second outer mounting bolt 76h: Bolt head 77b: Second inner fixture 78b: Second inner pressing plate 79b: Second inner mounting bolt 80: Third annular seal device 81, 81c: Third seal assembly 82, 82a, 82b, 82c: Seal plate group 83, 83a, 83b: sealing plate 84: Outer frame 85: Inner frame 86: Outer pin 87: Inner pin 89: Welded parts 90: Spacer 91: Outer frame contact surface 92: Frame side recess 93; Pressing plate contact surface 94: Pressing plate side recess 95,100: Spacer movement restraint device 96: Spring 97,101: Spring support frame 102: Frame body 102p: Contact surface of components 103: Frame flange 98,105:Spring cover 106: Cover body 106p: Spacer contact surface 107: Cover flange 99a, 99b, 110: Jig 111: Clamping jig 112:Finger support rod 112h: hole 113: First finger 113t: First tapered surface 114:Second finger 114t: Second tapered surface 115: Presser bar HG: Exhaust gas HP: Exhaust passage S1: First outer space S2: Second outer space S3: Between frame and relief face Pr: Planned placement position SR: Sealing plate array Ar: Axis line Ac: central axis Da: Axial direction Dau: Axis upstream side Dad: Downstream of the axis Dc: Circumferential direction Dr: Radial direction Dri: Radial inner direction Dro: Radial outer side Dac: Central axis direction

Claims

1. a first outer diffuser having a cylindrical shape centered on an axis and defining a radially outer edge of an upstream portion of an exhaust flow passage through which exhaust gas that has rotated the turbine rotor passes; a second external diffuser that is cylindrical about the axis and that is disposed with a gap between the first external diffuser and the first external diffuser on the downstream side of the axial direction in which the axis extends, and that defines a radially outer edge of a downstream portion of the exhaust flow passage through which exhaust gas that has passed through the first external diffuser passes; an exhaust casing having a cylindrical shape centered on the axis and covering an outer peripheral side of the first outer diffuser; an exhaust chamber having a cylindrical shape centered on the axis and covering the outside of the second outer diffuser; a first annular seal device annular about the axis; a second annular seal device annular about the axis; a third annular seal device annular about the axis; Equipped with The exhaust casing includes a cylindrical exhaust casing body centered on the axis, and an exhaust casing flange extending radially outward relative to the axis from an end of the exhaust casing body downstream of the axis, the exhaust chamber includes a cylindrical exhaust chamber main body centered on the axis, and an exhaust chamber flange extending radially outward from an end of the exhaust chamber main body on an upstream side of the axis and connected to the exhaust casing flange, the first annular seal device is provided in the first outer diffuser so as to suppress the exhaust gas from flowing into a first outer space between the first outer diffuser and the exhaust casing main body, the second annular seal device is provided in the second outer diffuser so as to suppress the exhaust gas from flowing into a second outer space between the second outer diffuser and the exhaust chamber main body, the third annular seal device is disposed between the first annular seal device and the second annular seal device in the axial direction, the third annular sealing device is provided at an end of the first outer diffuser on a downstream side in the axial direction so as to suppress the flow of the exhaust gas toward the first annular sealing device, or is provided at an end of the second outer diffuser on an upstream side in the axial direction so as to suppress the flow of the exhaust gas toward the second annular sealing device. Exhaust equipment.

2. The exhaust system according to claim 1, the third annular seal device has a plurality of third seal assemblies arranged in a circumferential direction with respect to the axis line, Each of the plurality of third seal assemblies includes a seal plate extending in a radial direction and a circumferential direction relative to the axis, an inner frame supporting a radially inner edge of the seal plate relative to the axis, and an outer frame supporting a radially outer edge of the seal plate. Exhaust equipment.

3. The exhaust system according to claim 2, the third annular sealing device is provided at an end of the second outer diffuser downstream in the axis direction so as to suppress the flow of the exhaust gas toward the second annular sealing device, the exhaust casing flange includes a connection portion having an exhaust casing contact surface that comes into contact with the exhaust casing flange, and a relief portion having an exhaust casing relief surface located radially inward and upstream of the exhaust casing contact surface, the exhaust chamber flange includes a connection portion having an exhaust chamber contact surface that comes into contact with the exhaust casing contact surface, and a relief portion that is located radially inward and downstream of the exhaust chamber contact surface in the axial direction, and has an exhaust chamber relief surface that faces the exhaust casing relief surface at a distance in the axial direction, the outer frame of each of the plurality of third seal assemblies is disposed between the exhaust casing relief surface and the exhaust chamber relief surface so as to be movable in the radial direction; Exhaust equipment.

4. The exhaust system according to claim 3, the third annular seal device has a spacer that is disposed between the outer frame and the exhaust chamber relief surface of each of the plurality of third seal assemblies and that restricts movement of the outer frame of each of the plurality of third seal assemblies in the axial direction while allowing movement of the outer frame in the radial direction. Exhaust equipment.

5. The exhaust system according to claim 4, the second annular seal device has a second member disposed between the frame and the relief surface and immovable relative to the exhaust chamber, the third annular seal device includes a spacer movement suppressor that increases a frictional force between the spacer and the second member and suppresses movement of the spacer in the radial direction and the axial direction. Exhaust equipment.

6. The exhaust system according to claim 5, the first annular seal device has a first member that faces the spacer across an interval in the axial direction and is provided so as to be immovable relative to the exhaust casing, The spacer movement suppressing device includes a spring that generates an elastic force in the axial direction, a spring support frame that covers one end of the spring in the axial direction (the upstream side in the axial direction) and contacts the first member, and a spring cover that covers the other end of the spring in the axial direction and contacts the spacer. Exhaust equipment.

7. The exhaust system according to claim 6, the spring support frame includes a frame body that covers the one end of the spring in the axial direction, and a frame flange, the frame body has a member contact surface that contacts the first member, the frame flange is located on the other side of the member contact surface in the axial direction and protrudes from the frame main body in the circumferential direction, the spring cover includes a cover body that covers the other end of the spring in the axial direction, and a cover flange; the cover body has a spacer contact surface that contacts the spacer, the cover flange is located on the one side of the spacer contact surface in the axial direction and protrudes from the cover body in the circumferential direction, The cover flange faces the frame flange with a gap in the axial direction. Exhaust equipment.

8. The exhaust system according to claim 6, The spacer has a recess formed therein that is recessed in the axial direction and into which a part of the spring cover fits. Exhaust equipment.

9. The exhaust system according to any one of claims 3 to 8, the inner frame of each of the plurality of third seal assemblies is fixed to an end of the first outer diffuser on a downstream side in the axial direction by welding. Exhaust equipment.

10. The exhaust system according to any one of claims 2 to 8, The seal plate of at least one third seal assembly among the plurality of third seal assemblies has a radially outer edge whose circumferential length is equal to a radially inner edge whose circumferential length is equal to Among the plurality of third seal assemblies, the seal plates of the other third seal assemblies except for the at least one third seal assembly have a circumferential length of the radially outer edge that is longer than a circumferential length of the radially inner edge. Exhaust equipment.

11. The exhaust equipment according to any one of claims 1 to 8; a compressor capable of compressing air to generate compressed air; a combustor capable of combusting fuel in the compressed air to generate combustion gas; a turbine that can be driven by the combustion gas from the combustor; Equipped with the turbine includes a turbine rotor rotatable about the axis and a turbine casing covering an outer periphery of the turbine rotor, the turbine rotor includes a rotor shaft extending in the axial direction centered on the axis, and a plurality of rotor blade rows attached to the rotor shaft and arranged in the axial direction at intervals in the axial direction, the turbine casing covers an outer periphery of a portion of the turbine rotor where the plurality of blade rows are present, The exhaust casing of the exhaust facility is connected to an end of the turbine casing on the downstream side of the axis. Gas turbine.

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