JP2013181672A - Combustor, and gas turbine with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a sealing structure for sealing a gap among an inner cylinder generating a combustion gas, a tail pipe with a distal end part of the inner cylinder inserted into a base end part spaced apart at an outer peripheral side, the outer peripheral side of the distal end part of the inner cylinder, and an inner peripheral side of the base end part of the tail pipe.SOLUTION: A sealing structure 40 has: an annular floating ring 41 externally covering a distal end part 22 of an inner cylinder 20 relatively movably to the inner cylinder 20 and a tail pipe 30; and an annular groove 47 formed in a base end part 31 of the tail pipe 30, recessed in a direction retreating from the distal end part 22 of the inner cylinder 20 in a radial direction, and having an outer peripheral side of the floating ring 41 relatively movably getting therein.

Description

  The present invention includes a combustor having an inner cylinder in which combustion gas is generated by supplying air and fuel, and a tail cylinder that sends out combustion gas generated in the inner cylinder, and the same. Related to gas turbines.

  The gas turbine includes a compressor that generates compressed air, a combustor that mixes fuel with compressed air and burns to generate combustion gas, and a turbine that is rotationally driven by the combustion gas. The combustor includes a fuel supplier that injects fuel together with compressed air, an inner cylinder that supplies compressed air and fuel to generate combustion gas, and a tail that sends combustion gas generated in the inner cylinder to a turbine. And a cylinder.

  The distal end portion of the inner cylinder is inserted on the inner peripheral side of the proximal end portion of the tail cylinder. There is a gap between the outer peripheral side of the distal end portion of the inner cylinder and the inner peripheral side of the proximal end portion of the tail cylinder to allow expansion and displacement due to heat of the inner cylinder and the tail cylinder. In order to seal this gap, in the technique described in Patent Document 1, an elastic spring seal is disposed between the outer peripheral side of the distal end portion of the inner cylinder and the inner peripheral side of the proximal end portion of the tail cylinder. Yes.

  This spring seal is disposed between the outer peripheral side of the distal end portion of the inner cylinder and the inner peripheral side of the proximal end portion of the tail cylinder in a state of being crushed in the radial direction of the inner cylinder. With this arrangement, one end of the spring seal is fixed to the outer peripheral surface of the tip of the inner cylinder, and the other end is pressed against the inner peripheral surface of the tail cylinder by its own restoring force. .

JP 2006-312903 A

  However, when the spring seal is arranged as described in Patent Document 1, self-excited vibration is generated in the spring seal during operation of the gas turbine. For this reason, a spring seal in a high temperature environment may be fatigued by self-excited vibration and cracks may occur in a relatively short period of time.

  Therefore, the present invention pays attention to such problems of the prior art, and an object of the present invention is to provide a combustor and a gas turbine equipped with the combustor to suppress damage to the sealing structure.

A combustor according to the invention for solving the above problems is
The inner cylinder in which combustion gas is generated by supplying air and fuel, and the distal end portion of the inner cylinder is inserted into the base end portion with a gap on the outer peripheral side, and the inner cylinder is generated inside the inner cylinder. A transition piece for sending combustion gas, and a sealing structure for sealing the gap between the outer peripheral side of the distal end portion of the inner cylinder and the inner peripheral side of the proximal end portion of the tail cylinder,
The sealing structure includes an annular ring member sheathed at the tip of the inner cylinder so as to be relatively movable with respect to the inner cylinder and the tail cylinder, and the tip and the tail cylinder of the inner cylinder. An annular groove is formed on one side of the base end portion and is recessed in a direction away from the other, and the outer peripheral side or the inner peripheral side of the ring member is inserted in a relatively movable manner.

  In the combustor, a gap between the outer peripheral side of the distal end portion of the inner cylinder and the inner peripheral side of the proximal end portion of the tail cylinder can be sealed with a sealing structure. In addition, in the combustor, since the ring member having the sealing structure can move relative to both the inner cylinder and the tail cylinder, fatigue damage of the ring member due to deformation caused by self-oscillation can be avoided.

  Here, in the combustor, when the side from which the combustion gas is sent out from the tail cylinder with respect to the inner cylinder is the downstream side, at least a downstream portion of the ring member is cooled by cooling air. Preferably means are provided. In this case, the cooling means may have a cooling air passage that penetrates from the upstream side opposite to the downstream side of the ring member to the downstream side and through which the cooling air passes. Further, the cooling means may have a cooling air passage that penetrates from the outer peripheral side of the transition piece to the inner peripheral side and through which the cooling air passes.

  In the combustor, thermal damage of the ring member due to high-temperature combustion gas generated in the inner cylinder can be suppressed.

  Further, in the combustor, the ring member includes a flange portion at least partially entering the groove, and a radial portion of the inner cylinder that is located on the opposite side of the groove with respect to the flange portion. And a width of the base portion in the upstream / downstream direction when the direction in which the combustion gas is sent out from the tail cylinder with respect to the inner cylinder is defined as an upstream / downstream direction. May be wider than the width of the groove in the upstream / downstream direction.

  In the combustor, the upstream and downstream of the gap between the peripheral surface of the end of the inner cylinder and the base end of the tail cylinder where the groove is not formed, and the base portion facing the peripheral surface Since the length in the direction is relatively long, the resistance to the fluid trying to pass through the gap is increased, and the sealing effect can be enhanced.

  In the combustor, a surface of the base portion of the ring member that faces the other peripheral surface of the distal end portion of the inner cylinder and the proximal end portion of the tail cylinder where the groove is not formed. An annular seal groove that is recessed in the direction in which the groove is recessed may be formed.

  In the combustor, sealing of a gap between the peripheral surface of the end portion of the inner cylinder at the tip end portion and the base end portion of the tail cylinder where the groove is not formed and the base portion facing the peripheral surface is provided. The effect can be further enhanced.

Further, a gas turbine for solving the above problems is
It is provided with the said combustor and the turbine driven with the said combustion gas sent out from the said transition piece of the said combustor.

  Since the gas turbine includes the combustor, it is possible to avoid fatigue damage to the ring member due to deformation caused by the self-vibration of the ring member having a sealing structure.

  In the present invention, fatigue damage of the ring member due to deformation caused by self-excited vibration of the ring member constituting the sealing structure can be avoided. Therefore, according to the present invention, damage to the sealing structure can be suppressed.

It is a principal part notched side view of the gas turbine in 1st embodiment which concerns on this invention. It is sectional drawing around the combustor of the gas turbine in 1st embodiment which concerns on this invention. It is principal part sectional drawing of the combustor in 1st embodiment which concerns on this invention. It is the IV-IV sectional view taken on the line in FIG. It is principal part sectional drawing of the combustor in the modification of 1st embodiment which concerns on this invention. It is principal part sectional drawing of the combustor in the other modification of 1st embodiment which concerns on this invention. It is principal part sectional drawing of the combustor in 2nd embodiment which concerns on this invention.

  Hereinafter, embodiments of a gas turbine according to the present invention will be described with reference to the drawings.

"First embodiment"
First, a gas turbine according to a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the gas turbine GT according to the present embodiment includes a compressor 1 that generates compressed air, a combustor 3 that mixes fuel with compressed air and burns to generate combustion gas, and is rotated by the combustion gas. And a turbine 5 to be driven. The turbine 5 includes a turbine casing 6 that forms a casing 7 therein, and a turbine rotor 8 that is rotatably provided in the casing 7.

  The compressor 1 takes in external air from the air intake port 2 and compresses the air to generate compressed air. The combustor 3 mixes fuel with the compressed air from the compressor 1 and burns it. The high-temperature and high-pressure combustion gas generated by the combustion of the fuel drives the turbine rotor 8 to rotate.

  As shown in FIG. 2, the combustor 3 includes a fuel supply unit 10 that injects the compressed air A and fuel from the compressor 1, and a compressed gas A and fuel from the fuel supply unit 10 that are supplied into the combustion gas. An inner cylinder 20 for generating G, a tail cylinder 30 for sending the combustion gas G generated in the inner cylinder 20 to the turbine 5, and a bypass pipe 50 for sending the compressed air A into the tail cylinder 30. Yes. The inner cylinder 20, the tail cylinder 30, and the bypass pipe 50 of the combustor 3 are all disposed in the casing 7 of the turbine 5.

  The fuel supply unit 10 supplies pilot fuel and compressed air A from the compressor 1 into the inner cylinder 20, and forms a diffusion flame in the inner cylinder 20, the main fuel and the compressor 1. The compressed air A is premixed and supplied into the inner cylinder 20 as a premixed gas, and a plurality of nozzles 12 for forming a premixed flame in the inner cylinder 20 are provided.

  The inner cylinder 20 has a cylindrical shape, the fuel supply device 10 is provided at one end, and an opening 25 is formed at the other end. In the following description, one end portion is referred to as a base end portion 21, and the other end portion is referred to as a tip end portion 22. The base end portion 21 side that is one end portion is an upstream side, and the tip end portion 22 that is the other end portion. This side is the downstream side.

  The tail cylinder 30 has a cylindrical shape, and openings 35 and 36 are formed at both ends. Of both ends, the inner diameter of the opening 35 at the upstream end is larger than the outer diameter of the tip 22 of the inner cylinder 20. In the following, the upstream end of the transition piece 30 is referred to as a proximal end 31 and the downstream end is referred to as a distal end 32. The distal end portion 22 of the inner cylinder 20 is inserted into the proximal end portion 31 of the tail cylinder 30. There is an annular gap S between the inner peripheral side of the proximal end portion 31 of the tail cylinder 30 and the outer peripheral side of the distal end portion 22 of the inner cylinder 20. This gap S is sealed by the sealing structure 40.

  The fuel supplier 10 is fixed to the upstream side of the turbine casing 6. The inner cylinder 20 is supported by the fuel supplier 10 whose base end 21 is fixed to the turbine casing 6, and whose front end 22 is provided in the turbine casing 6 together with the base end 31 of the tail cylinder 30. It is supported by the member 59. The distal end portion 32 of the transition piece 30 is connected to the turbine side gas flow path 9 of the turbine 5 and is supported by a member that forms the turbine side gas flow path 9. One end of the bypass pipe 50 is attached to the turbine casing 6, and the other end is connected to the middle trunk of the tail cylinder 30.

  The pilot burner 11 of the fuel supplier 10 supplies pilot fuel and compressed air A into the inner cylinder 20 to form a diffusion flame in the inner cylinder 20. The plurality of nozzles 12 premix the main fuel and the compressed air A and supply the premixed gas into the inner cylinder 20. This premixed gas is ignited by a diffusion flame. As a result, a premixed flame is formed in the inner cylinder 20. The combustion gas G generated by the combustion of the pilot fuel and the main fuel flows into the tail cylinder 30 from the opening 25 of the inner cylinder 20 and is sent from the tail cylinder 30 into the turbine side gas flow path 9. The combustion gas G that has entered the turbine-side gas flow path 9 rotates the turbine rotor 8 as described above. Compressed air A from the compressor 1 is also supplied from the bypass pipe 50 into the tail cylinder 30 without passing through the fuel supplier 10 as necessary.

  As described above, there is an annular gap S between the outer peripheral side of the distal end portion 22 of the inner cylinder 20 and the inner peripheral side of the proximal end portion 31 of the tail cylinder 30. The gap S is provided to allow expansion and displacement of the inner cylinder 20 and the tail cylinder 30 due to heat. In order to seal the gap S, the sealing structure 40 is provided in the gap S as described above.

  As shown in FIGS. 3 and 4, the sealing structure 40 is formed on an annular floating ring (ring member) 41 sheathed on the distal end portion 22 of the inner cylinder 20 and a proximal end portion 31 of the tail cylinder 30, An annular groove 47 into which the outer peripheral side of the floating ring 41 enters is provided.

  The floating ring 41 includes a cylindrical base portion 42 having an inner diameter R3 (see FIG. 4) slightly larger than the outer diameter R4 of the distal end portion 22 of the inner cylinder 20, and an outer peripheral side from the downstream end of the base portion 42. And an extending flange portion 44. A plurality of cooling air holes (cooling air passages) 43 penetrating from the upstream end to the downstream end are formed in the base portion 42 at intervals in the circumferential direction. The floating ring 41 is formed of a nickel base alloy having high heat resistance and corrosion resistance, such as Hastelloy (trademark of Haynes International, Inc., USA).

  An annular groove 47 formed in the base end portion 31 of the transition piece 30 is recessed from the inner peripheral side of the transition piece 30 toward the outer peripheral side.

  The tail cylinder 30 includes a cylindrical cylinder main body 33, a flange portion 35 extending from the downstream end of the cylinder main body 33 to the outer peripheral side, and a groove forming piece fixed to the outer peripheral end portion of the flange portion 35. 36. The groove forming piece 36 has an L-shaped cross section, forms a portion corresponding to one arm of the L shape, and has a groove bottom forming portion 37 fixed to the outer peripheral end of the flange portion 35, A groove wall forming portion 38 that forms a portion corresponding to the other arm and faces the flange portion 35 with a space therebetween is provided. The groove 47 described above is formed by the flange portion 35 of the transition piece 30 and the groove forming piece 36. That is, the groove bottom surface 48 of the groove 47 is formed by the groove bottom forming portion 37 of the groove forming piece 36, and the pair of side walls of the groove 47 is formed by the flange portion 35 of the tail tube 30 and the groove wall forming portion 38 of the groove forming piece 36. Has been.

  The width W1 in the upstream / downstream direction of the groove 47 (see FIG. 3) is narrower than the width W3 in the upstream / downstream direction of the base portion 42 of the floating ring 41 and wider than the width W2 in the upstream / downstream direction of the flange portion 44 of the floating ring 41. Further, the diameter R1 (see FIG. 4) of the groove bottom surface 48 of the annular groove 47 is larger than the outer diameter R2 of the flange portion 44 of the floating ring 41. For this reason, there are gaps in the upstream and downstream directions and in the radial direction between the surface of the flange portion 44 of the floating ring 41 and the inner surface of the groove 47. Further, as described above, the inner diameter R3 of the base portion 42 of the floating ring 41 is slightly larger than the outer diameter R4 of the distal end portion 22 of the inner cylinder 20. Therefore, even if the outer peripheral side of the flange portion 44 of the floating ring 41 enters the groove 47, the floating ring 41 is relatively movable with respect to the tail tube 30 in the upstream and downstream directions and in the radial direction. In addition, the floating ring 41 can be moved relative to the inner cylinder 20 in the upstream / downstream direction and the radial direction.

  When the fuel burns in the inner cylinder 20 of the combustor 3, each of the inner cylinder 20, the tail cylinder 30, and the floating ring 41 constituting a part of the sealing structure 40 is thermally expanded. Since the inner end 20 of the inner cylinder 20 is supported by the fuel supply device 10, the inner cylinder 20 extends downstream in the upstream / downstream direction. Moreover, since the tip 32 of the tail cylinder 30 is connected to the turbine-side gas flow path 9 of the turbine 5, the tail cylinder 30 extends upstream in the upstream / downstream direction. For this reason, the inner cylinder 20 and the tail cylinder 30 expand in the upstream and downstream directions, respectively, in the direction in which the distal end portion 22 of the inner cylinder 20 enters into the proximal end portion 31 of the tail cylinder 30. Here, the floating ring 41 is slightly different from the tail tube 30 by the difference between the width W1 of the groove 47 in the upstream / downstream direction and the width W2 of the flange portion 44 of the floating ring 41 in the upstream / downstream direction. The inner cylinder 20 can be freely moved in the upstream and downstream directions. Therefore, in the combustor 3 of the present embodiment, even if the floating ring 41 is provided in the gap S between the inner cylinder 20 and the tail cylinder 30, the distal end portion 22 of the inner cylinder 20 with respect to the proximal end portion 31 of the tail cylinder 30. The relative displacement in the upstream / downstream direction is not restricted, and expansion and displacement in the upstream / downstream direction due to the heat of the tail cylinder 30 and the inner cylinder 20 can be allowed.

  In addition, each of the inner cylinder 20, the tail cylinder 30, and the floating ring 41 thermally expands in the direction in which the diameter increases. The inner diameter R3 of the floating ring 41 is slightly larger than the outer diameter R4 of the distal end portion 22 of the inner cylinder 20 as described above. For this reason, there is a slight gap between the outer peripheral side of the distal end portion 22 of the inner cylinder 20 and the inner peripheral side of the floating ring 41. Further, the diameter R1 of the groove bottom surface 48 of the groove 47 formed in the tail cylinder 30 is larger than the outer diameter R2 of the floating ring 41 as described above. For this reason, there is also a gap between the inner peripheral side of the groove bottom surface 48 of the groove 47 formed in the tail cylinder 30 and the outer peripheral side of the floating ring 41. Therefore, in the present embodiment, even if the floating ring 41 is provided in the gap S between the inner cylinder 20 and the transition piece 30, the radial direction of the distal end portion 22 of the inner cylinder 20 with respect to the proximal end portion 31 of the transition piece 30. Expansion and displacement can be tolerated.

  When fuel is combusting in the inner cylinder 20 of the combustor 3, the pressure inside the casing 7 of the turbine 5 and outside the inner cylinder 20 and the tail cylinder 30 is greater than the pressure inside the inner cylinder 20 and the tail cylinder 30. high. For this reason, the compressed air A sent from the compressor 1 into the passenger compartment 7 enters the gap between the outer peripheral side of the tip 22 of the inner cylinder 20 and the inner peripheral side of the floating ring 41, and the tail cylinder 30. An attempt is made to enter the tail tube 30 through a gap between the inner peripheral side of the groove bottom surface 48 of the formed groove 47 and the outer peripheral side of the floating ring 41.

  Since the pressure outside the inner cylinder 20 and the tail cylinder 30 when fuel is burning in the inner cylinder 20 of the combustor 3 is higher than the pressure inside the inner cylinder 20 and the tail cylinder 30 as described above, the floating ring The upstream side of 41 is higher in pressure than the downstream side. For this reason, the floating ring 41 tends to move toward the downstream side. However, since the flange portion 44 of the floating ring 41 penetrates into the groove 47 formed in the tail tube 30, the flange of the tail tube 30 located on the downstream side of the flange portion 44 of the floating ring 41. It contacts the part 35 and the movement of the floating ring 41 to the downstream side is restricted. Thus, when the fuel is combusting in the inner cylinder 20 of the combustor 3, the flange portion 44 of the floating ring 41 and the flange portion 44 of the tail cylinder 30 come into contact with each other. Compressed air A that has been fed into the tail cylinder 30 through a gap between the inner peripheral side of the groove bottom surface 48 and the outer peripheral side of the floating ring 41 is compressed into the tail ring 30. It is sealed between the flange portion 44 and the flange portion 35 of the tail tube 30.

  As described above, the width W3 in the upstream / downstream direction of the base portion 42 of the floating ring 41 is wider than the width W1 in the upstream / downstream direction of the groove 47 formed in the tail tube 30. For this reason, the width in the upstream / downstream direction of the gap between the outer peripheral surface of the inner cylinder 20 and the inner peripheral surface of the floating ring 41, that is, the width W3 in the upstream / downstream direction of the base portion 42 is relatively wide. Therefore, the resistance to the compressed air A that tends to enter the tail cylinder 30 through the gap between the outer peripheral surface of the inner cylinder 20 and the inner peripheral surface of the floating ring 41 is large, and the tail cylinder 30 passes through this gap S. It is possible to seal the compressed air A trying to enter inside to some extent.

  As described above, in the present embodiment, the clearance S between the outer peripheral side of the inner cylinder 20 and the inner peripheral side of the tail cylinder 30 is allowed while allowing expansion and displacement of the tail cylinder 30 and the inner cylinder 20 due to heat. It can be sealed. In the present embodiment, even if the floating ring 41 vibrates by itself, the floating ring 41 can be moved relative to the inner cylinder 20 and the tail cylinder 30, so that one end is fixed to the inner cylinder. Fatigue damage due to deformation caused by self-oscillation, such as conventional spring seals, can be avoided.

  By the way, when the gap S between the outer peripheral side of the inner cylinder 20 and the inner peripheral side of the tail cylinder 30 is sealed, a part of the high-temperature combustion gas G that is generated in the inner cylinder 20 and flows into the tail cylinder 30. May flow backward and come into contact with the downstream surface of the floating ring 41 sealing the gap S. For this reason, the floating ring 41 may be damaged by the high-temperature combustion gas G. Therefore, in the present embodiment, a plurality of cooling air holes 43 penetrating from the upstream end to the downstream end are formed in the base portion 42 of the floating ring 41, and the inner cylinder 20 and the tail are passed through the cooling air holes 43. A small amount of compressed air A outside the cylinder 30 flows as cooling air downstream of the floating ring 41. As a result, the floating ring 41 is cooled by the compressed air A as cooling air, and the high-temperature combustion gas G flows backward in the gap S between the outer peripheral side of the inner cylinder 20 and the inner peripheral side of the tail cylinder 30. Can be suppressed. Therefore, in this embodiment, thermal damage of the floating ring 41 due to the high-temperature combustion gas G can be suppressed.

  As described above, in the present embodiment, fatigue damage due to self-vibration of the floating ring 41 and thermal damage due to the high-temperature combustion gas G can be suppressed, so that the maintainability of the combustor 3 can be improved.

  In the above embodiment, in order to suppress thermal damage of the floating ring 41 due to the high-temperature combustion gas G, the cooling air hole 43 penetrating the base portion 42 of the floating ring 41 is formed as the cooling air passage. Instead of the air hole 43, a groove that is recessed toward the outer peripheral side and extends in the upstream / downstream direction may be formed on the inner peripheral surface of the base portion 42. Further, the cooling air passage may be formed in the flange portion 44 instead of the base portion 42.

  Further, the above is an example in which the cooling air passage is formed in the floating ring 41, but the cooling air passage 39 may be formed in the tail tube 30 as shown in FIG. In this case, it is preferable to form the cooling air passage 39 so that the compressed air A outside the tail cylinder 30 reaches the downstream side surface of the floating ring 41. Further, a cooling air passage may be formed in both the floating ring 41 and the transition piece 30.

  Further, in the floating ring 41 of the above embodiment, the inner peripheral surface of the base portion 42 is flat in the upstream and downstream directions. However, as shown in FIG. 6, the outer peripheral surface is formed on the inner peripheral surface of the base portion 42a of the floating ring 41a. Compressed air that forms a seal groove 45 that is recessed toward the side and extends in the circumferential direction, enters the tail cylinder 30 through a gap between the outer peripheral surface of the inner cylinder 20 and the inner peripheral surface of the floating ring 41. The resistance to A may be increased, and the sealing ability of the compressed air A that attempts to enter the tail cylinder 30 through the gap S may be increased.

"Second embodiment"
Next, a gas turbine according to a second embodiment of the present invention will be described with reference to FIG.

  The gas turbine of the present embodiment differs from the first embodiment in the sealing structure 40b between the outer peripheral side of the distal end portion 22 of the inner cylinder 20b and the inner peripheral side of the proximal end portion 31 of the tail cylinder 30b. The configuration is basically the same as that of the gas turbine of the first embodiment. Therefore, hereinafter, the sealing structure 40b of the present embodiment will be mainly described.

  The sealing structure 40b of this embodiment includes an annular floating ring 41b sheathed on the distal end portion 22 of the inner cylinder 20b, and an annular groove formed in the distal end portion 22 of the inner cylinder 20b and into which the inner peripheral side of the floating ring 41b enters. 47b.

  The floating ring 41b includes a cylindrical base portion 42b having an outer diameter slightly smaller than the inner diameter of the base end portion 31 of the tail tube 30b, and a flange portion extending from the downstream end of the base portion 42b to the inner peripheral side. 44b. A plurality of cooling air holes 43 (cooling air passages) penetrating from the upstream end to the downstream end are formed in the base portion 42b at intervals in the circumferential direction.

  The inner cylinder 20b includes the same cylinder body 23 as the inner cylinder 20 in the first embodiment, a pair of groove forming rings 26 fixed to the outer periphery of the cylinder body 23 and spaced from each other in the upstream and downstream directions, have. The groove 47b of the sealing structure 40b is formed by the outer peripheral surface of the cylinder body 23 and the pair of groove forming rings 26. That is, the groove bottom surface of the groove 47 b is formed by the outer peripheral surface of the cylinder body 23, and the side wall of the groove 47 b is formed by the pair of groove forming rings 26.

  The width in the upstream / downstream direction of the groove 47b is narrower than the width in the upstream / downstream direction of the base portion 42b of the floating ring 41b, and wider than the width in the upstream / downstream direction of the flange portion 44b of the floating ring 41b. The diameter of the bottom surface of the annular groove 47b is smaller than the inner diameter of the flange portion 44b of the floating ring 41b. For this reason, even if the inner peripheral side of the flange portion 44b of the floating ring 41b enters the groove 47b, the floating ring 41b is relatively movable relative to the inner cylinder 20b in the upstream and downstream directions and in the radial direction. . Further, the floating ring 41b can be moved relative to the tail cylinder 30b in the upstream and downstream directions and in the radial direction.

  Therefore, in this embodiment as well as in the first embodiment, while allowing expansion and displacement due to heat of the inner cylinder 20b and the tail cylinder 30b, between the outer peripheral side of the inner cylinder 20b and the inner peripheral side of the tail cylinder 30b. Can be sealed, and fatigue damage due to deformation caused by self-oscillation can be avoided.

  Also in the present embodiment, as in the first embodiment, a plurality of cooling air holes 43 penetrating from the upstream end to the downstream end are formed in the base portion 42b of the floating ring 41b. For this reason, also in this embodiment, the thermal damage of the floating ring 41b by the high temperature combustion gas G can be suppressed.

  Also in this embodiment, a modification to the first embodiment may be applied. That is, in this embodiment, instead of the cooling air hole 43 (cooling air passage) penetrating the base portion 42b of the floating ring 41b, the outer peripheral surface of the base portion 42b is recessed toward the inner peripheral side and is in the upstream and downstream direction. A groove extending in the direction may be formed. Further, the cooling air passage may be formed in the flange portion 44b instead of the base portion 42b. Further, the cooling air passage may be formed in the tail cylinder 30b. In the present embodiment, a seal groove that is recessed toward the inner peripheral side and extends in the circumferential direction may be formed on the outer peripheral surface of the base portion 42b.

  1: compressor, 3: combustor, 5: turbine, 6: turbine casing, 7: vehicle compartment, 8: turbine rotor, 10: fuel supply, 20, 20b: inner cylinder, 30, 30b: tail cylinder, 39 : Cooling air path, 40, 40b: sealing structure, 41, 41b: floating ring (ring member), 42, 42b: base part, 43: cooling air hole (cooling air path), 44, 44b: flange part, 45 : Seal groove, 47, 47b: Groove

Claims (7)

An inner cylinder in which combustion gas is generated by supplying air and fuel;
A tail tube in which a distal end portion of the inner cylinder is inserted into a base end portion with a gap on the outer peripheral side, and sends out the combustion gas generated inside the inner cylinder;
A sealing structure for sealing the gap between the outer peripheral side of the distal end portion of the inner cylinder and the inner peripheral side of the proximal end portion of the tail cylinder;
With
The sealing structure includes an annular ring member sheathed at the tip of the inner cylinder so as to be relatively movable with respect to the inner cylinder and the tail cylinder, and the tip and the tail cylinder of the inner cylinder. An annular groove that is formed in one of the base end portion and is recessed in a direction away from the other, and into which the outer peripheral side or inner peripheral side of the ring member is relatively movable,
Combustor characterized by that. The combustor according to claim 1.
A cooling means for cooling at least a downstream portion of the ring member with cooling air when the side from which the combustion gas is sent out from the tail cylinder with respect to the inner cylinder as a downstream side is provided;
Combustor characterized by that. The combustor according to claim 2, wherein
The cooling means has a cooling air path that penetrates from the upstream side opposite to the downstream side of the ring member to the downstream side and through which the cooling air passes.
Combustor characterized by that. The combustor according to claim 2 or claim 3,
The cooling means penetrates from the outer peripheral side of the transition piece to the inner peripheral side, and has a cooling air passage through which the cooling air passes.
Combustor characterized by The combustor according to any one of claims 1 to 4, wherein
The ring member includes a flange portion at least partially entering the groove, and a base portion that is positioned on the opposite side of the groove with respect to the flange portion in the radial direction of the inner cylinder and is fixed to the flange portion. And having
When the direction in which the combustion gas is delivered from the tail cylinder with respect to the inner cylinder as an upstream / downstream direction, the width of the base portion in the upstream / downstream direction is larger than the width of the groove in the upstream / downstream direction. wide,
Combustor characterized by that. The combustor according to claim 5.
In the base portion of the ring member, the groove is recessed on a surface of the distal end portion of the inner cylinder and the proximal end portion of the tail cylinder that faces the other peripheral surface where the groove is not formed. An annular seal groove is formed that is recessed in the protruding direction.
Combustor characterized by that. A combustor according to any one of claims 1 to 6,
A turbine driven by the combustion gas delivered from the transition piece of the combustor;
A gas turbine comprising:

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