JP6016655B2 - Gas turbine tail tube seal and gas turbine - Google Patents

Description

  The present invention relates to a gas turbine tail cylinder seal that seals between a combustor tail cylinder and a combustion gas flow path of a turbine, and a gas turbine using the same.

  The gas turbine includes a compressor, a combustor, and a turbine (not shown). According to this gas turbine, the compressed air compressed by the compressor is supplied to the combustor and is mixed and burned with fuel supplied separately. Combustion gas generated by this combustion is supplied to the turbine, and a rotational driving force is generated in the turbine.

  FIG. 6 shows a general configuration of the combustor. In the figure, reference numeral 20 denotes a combustor, which is fixed inside a passenger compartment 32. Reference numeral 21a denotes a pilot fuel nozzle, which is supplied with pilot fuel. Reference numeral 20b denotes a main fuel nozzle, and a plurality (for example, eight) are arranged circumferentially around the pilot fuel nozzle 21a. Reference numeral 22 denotes a transition piece that guides the high-temperature combustion gas G to the transition piece outlet 22a. Reference numeral 27 is a bypass pipe, and reference numeral 28 is a bypass valve. When the combustion air becomes insufficient due to load fluctuation, the bypass valve 28 is opened, and the air in the passenger compartment 32 is guided into the combustor 20. Reference numeral 180 denotes a gas turbine tail cylinder seal (hereinafter sometimes simply referred to as a tail cylinder seal), which is provided at the end of the tail cylinder outlet 22a, and the combustion gas flow path (gas path) Pg of the turbine and the tail cylinder 22 are provided. And seal the connection. A plurality of combustors 20 are arranged around a rotor (not shown) in the passenger compartment 32, and hot combustion gas G from these expands in the turbine, thereby rotating the rotor.

  In the combustor 20 having the above-described configuration, the fuel from the main fuel nozzle 21b is mixed with the air sucked from the passenger compartment 32, ignited by the flame of the pilot fuel from the pilot fuel nozzle 21a, and combusted in the combustion chamber. G is supplied to the combustion gas flow path Pg through the transition piece 22 from the transition piece outlet 22a. Since the wall surface of the tail cylinder 22 of the combustor 20 is constantly in contact with the high-temperature combustion gas G, it is cooled by flowing cooling air through a cooling passage provided inside the wall. The transition piece outlet 22a is connected to the inlet of the combustion gas flow path Pg via the transition piece seal 180, and the transition piece seal 180 is also cooled by the cooling air.

  FIG. 7 is an enlarged view of a portion A in FIG. 6 and shows a structure of a conventional tail tube seal. As shown in the figure, an outlet flange 23 is formed around the transition piece outlet 22a. The transition piece outlet 22a is connected to the combustion gas flow path Pg via a transition piece seal 180. A flange groove 81 having a U-shaped cross section that opens to the inner peripheral side of the transition piece outlet 22a is formed on the transition piece 22 side of the transition piece seal 180, and the outlet flange 23 of the transition piece outlet 22a is fitted into the flange groove 81. Is done. An engagement groove 82 having a U-shaped cross section that opens to the downstream side in the flow direction of the combustion gas flow path Pg (flow direction of the combustion gas) is formed on the combustion gas flow path Pg side of the transition piece seal 180. The upstream end portions of the outer shroud 43 and the inner shroud 45 of the first stationary blade stage 40a in the combustion gas flow path Pg are fitted into the joint groove 82, respectively.

  A plurality of cooling channels 185 are formed in the tail tube seal 180. The cooling flow path 185 allows a part of the compressed air in the passenger compartment 32 to flow as cooling air A, cooling the tail cylinder seal 180 itself, and film cooling of the outer shroud 43 and the inner shroud 45 of the first stationary blade stage 40a. I do. The cooling flow path 185 extends from the outer surface of the transition piece seal 180 facing the vehicle compartment 32 to the downstream side along the wall surface 84 facing the combustion gas flow path Pg of the wall portion 83 of the transition piece seal 180, and reaches the downstream end. Open to. High-pressure air in the passenger compartment 32 flows into the cooling flow path 185 as cooling air A, and the cooling air A flows through the wall portion 83 downstream to cool the wall surface 84 of the tail cylinder seal 180. The cooling air A in the cooling flow path 185 is discharged from the downstream end of the wall portion 83 to the upstream end of the combustion gas flow path Pg, and the inner peripheral surface of the outer shroud 43 and the outer peripheral surface of the inner shroud 45 are film cooled. To do. A cooling structure for this type of transition piece seal is disclosed in, for example, Patent Document 1 below.

Japanese Patent No. 4288147

By the way, in the gas turbine tail cylinder seal as described above, there is a demand for a structure that can cool the tail cylinder seal itself with less cooling air.
That is, the wall portion 83 of the transition piece seal 180 is cooled by the air in the passenger compartment 32 leaking from the gap between the upstream end thereof and the transition piece 22, but tends to become higher at the downstream side. is there. In the configuration of the above-described conventional transition piece seal 180, the outlet of the cooling flow path 185 is opened at the downstream end of the wall portion 83, so that the periphery of the outlet is easily damaged.

  Accordingly, an object of the present invention is to suppress damage around the outlet of the cooling flow path and reduce the amount of cooling air in the gas turbine tail cylinder seal and the gas turbine.

  As a means for solving the above problems, a gas turbine tail cylinder seal according to the present invention includes a combustor tail cylinder, an inner shroud and an outer shroud of a first stationary blade stage downstream of the tail cylinder in the flow direction of the combustion gas. And a gas turbine tail tube seal that seals between the inner and outer walls of the combustion gas flow path, and a wall that faces the combustion gas flow path. A first flow path for flowing air flowing in from the downstream side in the wall, and adjacent to the first flow path in the circumferential direction along the wall surface and perpendicular to the flow direction of the combustion gas in the wall. Formed in the wall, and flows in the upstream of the flow direction of the combustion gas in the wall, and formed in the wall, the first flow path and the second flow path Connect the downstream side of the A cooling flow path including a connection flow path communicating with the first flow path, the first flow path having an inlet opening communicating with the vehicle compartment on the upstream side of the wall, and the second flow path, An outlet opening that communicates with the combustion gas flow path at the wall surface of the wall portion is provided.

According to this configuration, the air that has flowed downstream through the first flow path reaches the second flow path through the connection flow path, and flows to the upstream side again through the second flow path, so that the cooling air is directed downstream. Compared with the case of flowing in only one direction, the length of the cooling flow path is increased, and the cooling area by the cooling air is increased. Thereby, the wall surface vicinity which faces a combustion gas flow path can be efficiently cooled with less cooling air.
Further, the outlet opening portion of the second flow path serving as the outlet of the cooling passage is disposed on the wall surface of the wall portion, so that the opening can be eliminated from the downstream end portion of the wall portion. Damage can be suppressed.

In the gas turbine tail cylinder seal according to the present invention, the outlet opening may be disposed between the two adjacent first flow paths on the downstream side of the inlet opening.
According to this configuration, since the cooling is performed by the cooling air flowing through the first flow paths disposed on both sides, the temperature around the outlet opening is further suppressed from being high, and the outlet opening is prevented from being damaged. be able to.

In the gas turbine tail tube seal according to the present invention, the outlet opening may be disposed in the vicinity of the inlet opening on the downstream side of the inlet opening.
According to this configuration, the air discharged from the outlet opening is cooled by the air just flowing in from the inlet opening, and the flow path length of the second flow path can be sufficiently secured. Therefore, by cooling the periphery of the outlet opening, it is possible to suppress damage around the outlet opening and to reduce the amount of cooling air.

In the gas turbine tail tube seal according to the present invention, the first flow path includes a first flow path main body extending along the wall surface, and the first flow path main body in the vicinity of the wall surface extending from the inlet opening to the combustion gas flow path side. An inlet channel connected to the outlet channel, and the inlet channel and the outlet opening may be close to each other.
According to this structure, the air discharged from the outlet opening and the vicinity of the outlet opening can be satisfactorily cooled by the air that has just flowed into the inlet channel.

In the gas turbine tail cylinder seal according to the present invention, a plurality of the cooling flow paths may be formed so as to be aligned in the circumferential direction.
According to this structure, a cooling flow path can be arrange | positioned over the whole wall part in the said upstream / downstream direction and the circumferential direction, and the wall surface vicinity can be cooled much more favorably.

In the gas turbine tail cylinder seal according to the present invention, the connection flow path may extend in the circumferential direction to communicate the first flow path and the second flow path of the plurality of cooling flow paths.
According to this configuration, the connection flow paths of the plurality of cooling flow paths can be formed by the flow paths that penetrate the wall portion in the circumferential direction, and the formation of the plurality of cooling flow paths can be facilitated.

In the gas turbine tail cylinder seal according to the present invention, the outlet opening may open at an upstream end of the wall surface and function as a film cooling hole for the wall surface.
According to this configuration, the wall surface can be satisfactorily cooled from the upstream end thereof.

In the gas turbine tail cylinder seal according to the present invention, the connection flow path may be impingement cooled to cool an inner wall surface by collision of air flowing through the first flow path.
According to this configuration, the impingement cooling around the connection flow path can be satisfactorily performed by the collision of the air flow when turning back from the first flow path to the second flow path, and the downstream end of the wall portion can be cooled.

  A gas turbine according to the present invention includes a gas turbine tail cylinder seal according to any one of claims 1 to 7, a combustor including the tail cylinder, and a turbine driven by combustion gas generated by the combustor. A gas turbine is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the damage around the exit of the cooling air in a gas turbine tail pipe seal can be suppressed, and the amount of cooling air can be reduced.

It is a side view including a partial section of a gas turbine in an embodiment of the present invention. It is a principal part enlarged view of FIG. It is sectional drawing orthogonal to the circumferential direction around the transition piece seal of the said gas turbine. It is the IV section enlarged view of FIG. FIG. 5 is a view taken in the direction of arrow V in FIG. It is explanatory drawing of the conventional gas turbine tail pipe seal and a combustor. It is the VII part enlarged view of FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

"gas turbine"
First, the basic configuration of the gas turbine according to the present embodiment will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1, a gas turbine 1 includes a compressor 10 that compresses outside air to generate compressed air, and a plurality of fuels that generate combustion gas by mixing fuel from a fuel supply source with the compressed air and burning it. Combustor 20 and a turbine 30 driven by the combustion gas.

The turbine 30 includes a casing 31 and a turbine rotor 33 that rotates around the rotor shaft (rotor axis) Ar in the casing 31. The turbine rotor 33 is connected to a generator (not shown) that generates power by rotating the turbine rotor 33, for example.
The compressor 10 is arranged on one side of the axial direction Da of the rotor shaft Ar with respect to the turbine 30. The casing 31 of the turbine 30 has a cylindrical shape centered on the rotor axis Ar.

The plurality of combustors 20 are arranged at intervals in the circumferential direction Dc around the rotor axis Ar, and the plurality of combustors 20 are attached to the casing 31.
Hereinafter, the side where the compressor 10 is arranged in the axial direction Da is the upstream side, and the opposite side is the downstream side. Further, in the radial direction Dr with the rotor axis Ar as the center, a side away from the rotor axis Ar is a radially outer side, and a side approaching the rotor axis Ar is a radially inner side. Moreover, regarding the flow direction of the combustion gas, the side on which the combustor 20 is disposed is the upstream side, and the side on which the opposite turbine 30 is disposed is the downstream side.

  As shown in FIG. 2, the turbine rotor 33 includes a rotor body 34 that extends in the axial direction Da around the rotor axis Ar, and a plurality of blade stages 35 that are attached to the rotor body 34 side by side in the axial direction Da. . Each blade stage 35 has a plurality of blades 36 arranged in the circumferential direction Dc around the rotor axis Ar. Each rotor blade 36 includes a rotor blade body 37 extending in the radial direction Dr, a platform 38 provided on the radially inner side of the rotor blade body 37, and a blade root 39 provided on the radially inner side of the platform 38. Each rotor blade 36 is fixed to the rotor body 34 by having a blade root 39 embedded in the rotor body 34.

  A stationary blade stage 40 is disposed on the upstream side of each blade stage 35. Each stationary blade stage 40 has a plurality of stationary blades 41 arranged in the circumferential direction Dc around the rotor axis Ar. Each stationary blade 41 includes a stationary blade body 42 extending in the radial direction Dr, an outer shroud 43 provided on the radially outer side of the stationary blade body 42, and an inner shroud 45 provided on the radially inner side of the stationary blade body 42. Have.

  A blade ring 50 having a cylindrical shape around the rotor axis Ar and fixed to the casing 31 is disposed radially outside the moving blade stage 35 and the stationary blade stage 40 and inside the casing 31 in the radial direction. . The blade ring 50 and the outer shroud 43 of the stationary blade 41 are connected by a heat shield ring 52.

  Between the outer shrouds 43 of the stationary blade stages 40 adjacent in the axial direction Da, a plurality of split rings 61 arranged in the circumferential direction Dc around the rotor axis Ar are arranged. The plurality of split rings 61 are arranged in a ring shape, and the rotor blade stage 35 is disposed on the radially inner side. The plurality of split rings 61 are each connected to the blade ring 50 by a heat shield ring 52.

  The combustor 20 includes a tail cylinder 22 that sends high-temperature and high-pressure combustion gas G to a turbine 30, and a fuel nozzle 21 that supplies fuel and compressed air into the tail cylinder 22. The upstream end of each of the inner shroud 45 and the outer shroud 43 of the first stator blade 41a constituting the most upstream first stator blade stage 40a is connected to the downstream flange of the transition piece 22, that is, the outlet flange 23. Is done.

  The compressed air generated by the compressor 10 enters the upstream side of the casing 31 (hereinafter, referred to as the vehicle compartment 32) and flows into the fuel nozzle 21 from the outer periphery of the combustor 20. The fuel nozzle 21 sprays fuel from the outside together with the compressed air into the tail cylinder 22. In the transition piece 22, the fuel is burned and combustion gas G is generated. This combustion gas G is a platform 38 of a plurality of blades 36 constituting the blade stage 35 between the inner shroud 45 and the outer shroud 43 of the plurality of stator blades 41 constituting the stationary blade stage 40 and downstream thereof. And the blade ring 37 in the process of passing between the rotor blade 36 and the split ring 61 disposed on the radially outer side of the rotor blade 36, and the turbine rotor 33 is rotated about the rotor axis Ar.

  That is, the combustion gas flow path (gas path) Pg through which the combustion gas G in the turbine 30 flows is downstream of the tail cylinder 22, and the inner shroud 45 and outer shroud 43 of the stationary blade 41 and the platform 38 of the moving blade 36 and the same. Is defined by a split ring 61 opposite to.

"Gas Turbine Seal"
Next, with reference to FIGS. 3 and 4, the gas turbine tail cylinder seal (hereinafter sometimes simply referred to as a tail cylinder seal) of the present embodiment will be described.
As shown in FIG. 3, the transition piece seal 80 is provided on the upstream side of the outlet flange 23 of the transition piece 22 of the combustor 20 and the inner shroud 45 and the outer shroud 43 of the first stationary blade 41a of the first stationary blade stage 40a. It is a sealing member which seals between the end portions.

The transition piece outlet 22a of the transition piece 22 is formed along a plane orthogonal to the flow direction of the combustion gas flow path Pg (flow direction of the combustion gas G). The transition piece outlet 22a has a substantially quadrangular shape when viewed from the flow direction of the combustion gas flow path Pg, and an outlet flange 23 is formed in a square ring around the periphery.
The outlet flange 23 has a pair of radial flange portions disposed in the radial direction Dr and a pair of circumferential flange portions disposed in the circumferential direction Dc across the opening of the transition piece outlet 22a. The transition piece seal 80 is disposed along a pair of circumferential flange portions.

  The pair of radial flange portions in the outlet flange 23 has other seal members (not shown) for sealing between the radial flange portions in the outlet flange 23 of the other tail tube 22 adjacent in the circumferential direction Dc. Be placed.

  The transition piece seal 80 disposed on the circumferential flange portion on the radially outer side of the outlet flange 23 engages with the circumferential flange portion on the radially outer side, and at the upstream end of the outer shroud 43 of the first stationary blade 41a. Engage with the part. The transition piece seal 80 disposed in the circumferential flange portion on the radially inner side of the outlet flange 23 engages with the circumferential flange portion on the radially inner side and at the upstream end of the inner shroud 45 of the first stationary blade 41a. Engage with the part. Engagement projections 44 are formed at the upstream end portions of the outer shroud 43 and the inner shroud 45 of the first stationary blade 41a so as to protrude upstream and engage the tail cylinder seal 80, respectively.

  In a cross section (corresponding to FIG. 3) orthogonal to the circumferential direction Dc at the tail tube outlet 22 a of the tail tube 22, the radially inner tail tube seal 80 and the radially outer tail tube seal 80 are the tail tube of the tail tube 22. The outlet 22a has a symmetrical configuration with respect to the rotor axis Ar. Hereinafter, the radially inner transition piece seal 80 will be described with reference to FIG. 4, and the radially outer transition piece seal 80 has a symmetric configuration and description thereof is omitted.

A flange groove 81 that is recessed radially inward is formed in the upstream portion of the transition piece seal 80 so as to extend in the circumferential direction Dc. In the flange groove 81, the outlet flange 23 (circumferential flange portion) of the tail cylinder 22 is fitted.
An engagement groove 82 that is recessed toward the upstream side in the flow direction of the combustion gas flow path Pg is formed in the downstream portion of the transition piece seal 80 so as to extend in the circumferential direction Dc. In the engaging groove 82, the engaging convex portion 44 of the inner shroud 45 of the first stationary blade 41a is fitted.

Hereinafter, a wall portion along the combustion gas flow path Pg in the transition piece seal 80 is denoted by reference numeral 83, and a wall surface facing the combustion gas flow path Pg in the wall section 83 is denoted by reference numeral 84.
A cooling channel 85 for cooling the periphery of the wall surface 84 is formed in the wall 83 of the tail cylinder seal 80.

  The cooling flow path 85 is formed along the wall surface 84 in the wall portion 83, and is formed by the first flow path 86, the second flow path 87, and the connection flow path 88. The first flow path 86 allows the cooling air A, which is a part of the compressed air flowing from the inside of the vehicle compartment 32 disposed on the outer periphery of the combustion gas flow path Pg, to flow downstream in the flow direction of the combustion gas G in the wall 83. This is a flow channel. The second flow path 87 is formed in the wall portion 83 along the flow direction of the combustion gas G on the wall surface 84 and adjacent to the first flow path 86 in the circumferential direction Dc, and has cooled through the first flow path 86. This is a flow path for flowing air A in the wall 83 to the upstream side in the flow direction of the combustion gas G. The connection flow path 88 is a flow path that is formed in the downstream end portion in the wall portion 83 and connects the downstream end portions of the first flow path 86 and the second flow path 87 to each other so as to be folded back. is there.

  A plurality of cooling flow paths 85 are formed so as to be aligned in the circumferential direction Dc, and substantially the entire wall surface 84 can be cooled. The connection flow path 88 of each cooling flow path 85 communicates with each other, and is formed as a through flow path 88A that penetrates the transition piece seal 80 along the circumferential direction Dc. Thereby, the connection flow paths 88 of the plurality of cooling flow paths 85 can be formed together by a processing tool or the like that penetrates the transition piece seal 80 in the circumferential direction Dc. The end portions on both sides in the circumferential direction Dc of the through channel 88A are closed by the plug p.

The first flow path 86 includes an inlet opening 86a that opens to the vehicle compartment 32 at the upstream end of the wall 83, and an inlet flow path 86b that extends from the inlet opening 86a toward the combustion gas flow path Pg along the radial direction Dr. And a first flow path body 86c extending from the end of the inlet flow path 86b on the wall surface 84 side to the downstream side along the wall surface 84.
The second flow path 87 includes an outlet opening 87a that opens to the combustion gas flow path Pg at the upstream end of the wall 83, and an outlet flow path that extends along the radial direction Dr from the outlet opening 87a to the vehicle compartment 32 side. 87b and a second flow path body 87c extending from the front end side of the outlet flow path 87b along the wall surface 84 to the downstream side in the flow direction of the combustion gas G.

  The first flow path 86 and the second flow path 87 are formed closer to the wall surface 84 in the thickness direction (radial direction Dr) of the wall portion 83. The outlet flow path 87b extending from the wall surface 84 to the second flow path body 87c is shorter than the inlet flow path 86b extending from the outer surface opposite to the wall surface 84 in the radial direction Dr in the wall portion 83 to the first flow path body 86c.

  The cooling air A, which is a part of the compressed air supplied from the compressor 10 into the passenger compartment 32, is a gap between the outlet flange 23 and the tail cylinder seal 80, and between the tail cylinder seal 80 and the first stationary blade 41a. It leaks from the gap between the inner shroud 45 and flows into the combustion gas flow path Pg. The leaked cooling air A cools the upstream end portion of the transition piece seal 80.

  A part of the cooling air A in the passenger compartment 32 flows into the plurality of cooling channels 85 from the plurality of inlet openings 86a. Since the plurality of cooling channels 85 are formed near the combustion gas channel Pg in the wall 83 of the transition piece seal 80, the cooling air A flowing through the plurality of cooling channels 85 causes combustion in the wall 83. The wall surface 84 side that is susceptible to heat from the combustion gas G flowing through the gas flow path Pg is cooled well.

  Each cooling flow path 85 flows the cooling air A that has flowed downstream through the first flow path 86, then turns this cooling air A back upstream through the connection flow path 88, and then again flows upstream through the second flow path 87. By flowing, the flow path length is doubled as compared with the case where the cooling air A is flowed only in one direction of the flow direction of the combustion gas G. Thereby, the cooling performance of the tail tube seal 80 can be enhanced even with the same air flow rate. When the plurality of cooling flow paths 85 communicate with each other through the through flow path 88A, variation in the air flow rate is suppressed, contributing to equalization of cooling.

  The cooling air A in the cooling channel 85 flows out into the combustion gas channel Pg from the outlet opening 87a. The outlet opening 87 a is desirably formed at the upstream end of the transition piece seal 80. The cooling air A that has flowed into the combustion gas flow path Pg from the outlet opening 87a cools the wall surface 84 of the tail tube seal 80 over a wide range from the upstream end to the downstream side in the flow direction of the combustion gas G. . That is, the outlet opening 87 a functions as a film cooling hole for the wall surface 84.

  The outlet opening 87a opens closer to the inlet opening 86a on the downstream side (first flow path body 86c side) than the inlet opening 86a. Note that “close to the inlet opening 86a” is a cross-sectional view of the wall surface 84 of the transition piece seal 80 from the combustion gas flow path Pg side toward the radially outer side or radially inner side (corresponding to FIG. 5). At least the outlet opening 87a needs to be disposed between the first flow paths 86 disposed closer to both sides of the circumferential direction Dc on the downstream side in the flow direction of the combustion gas G than the inlet opening 86a. Further, with respect to the flow direction of the combustion gas G, an isosceles triangle is formed between the outlet opening 87a and the two inlet openings 86a of the first flow path 86 on both sides in the circumferential direction Dc. It is most desirable to have the arrangement (the most upstream position).

  Due to the arrangement of the outlet opening 87a described above, the outlet opening 87a is close to the downstream end (end on the wall surface 84) in the radial direction Dr of the inlet passage 86b because the outlet passage 87b is short. Thereby, the periphery of the outlet opening 87a is cooled well, and damage around the outlet opening 87a is suppressed. In addition, since the flow path length in the flow direction of the second flow path 87 is sufficiently secured, there is an effect in reducing the amount of cooling air.

  Note that the position of the outlet opening 87a in the flow direction of the combustion gas G may be on the downstream side of the most upstream position as long as it is disposed between the adjacent first flow paths 86. In such a case, although it is slightly disadvantageous from the viewpoint of securing the flow path length of the second flow path 87 as much as possible, since the outlet opening 87a is sandwiched between the first flow paths 86, the periphery of the outlet opening 87a is the first. It is cooled by the cooling air A flowing through one flow path 86, and there is no possibility that the outlet opening 87a is damaged by high temperature.

  In addition, the cooling air A that has flowed downstream through the first flow path 86 collides with the downstream inner surface of the connection flow path 88 and turns back upstream, but the inner wall surface of the connection flow path 88 is caused by the collision of the cooling air A. Is impingement cooled. Thereby, the cooling effect on the downstream side of the transition piece seal 80 that tends to be relatively high is enhanced, and the downstream end portion of the transition piece seal 80 is prevented from being damaged. The cooling flow path 85 does not open at the downstream end portion of the transition piece seal 80, and the downstream end portion of the transition piece seal 80 is also prevented from being damaged in this respect.

  As described above, according to the gas turbine tail cylinder seal 80 of the present embodiment, it is formed along the wall surface 84 facing the combustion gas flow path Pg in the wall portion 83 facing the combustion gas flow path Pg. In addition, a plurality of cooling flow paths 85 that are folded back at the downstream end of the wall 83 are provided, and the first flow path 86 has an inlet opening 86 a that communicates with the vehicle compartment 32 on the upstream side of the wall 83, and the second flow When the passage 87 has the outlet opening 87a communicating with the combustion gas flow path Pg on the upstream side of the wall 83 and in the vicinity of the inlet opening 86a, the cooling air A flows in only one direction toward the downstream side. In comparison, the vicinity of the wall surface 84 can be efficiently cooled with less cooling air A. Further, the outlet opening 87a of the second flow path 87 serving as the outlet of the cooling flow path 85 is disposed between the adjacent first flow paths 86 on the upstream side of the wall 83, so that the downstream of the wall 83. It is possible to eliminate the opening from the high-temperature portion, and it is possible to suppress damage around the outlet of the cooling air A.

The present invention is not limited to the above-described embodiment. For example, the plurality of connection channels 88 may not communicate with each other, and a plurality of cooling channels 85 independent from each other may be formed.
Even if the outlet passage 87b of the cooling passage 85 is inclined so as to be located on the downstream side toward the combustion gas passage Pg, the cooling air A flowing out from the outlet passage 87b can easily flow along the wall surface 84. Good.
And the structure in the said embodiment is an example of this invention, A various change is possible in the range which does not deviate from the summary of the said invention.

DESCRIPTION OF SYMBOLS 1 Gas turbine 20 Combustor 22 Tail tube 30 Turbine 32 Car compartment A Cooling air (air)
40a First stationary blade stage 43 Outer shroud 45 Inner shroud 80 Gas turbine tail cylinder seal Pg Combustion gas flow path 83 Wall portion 84 Wall surface Dc Circumferential direction 85 Cooling flow path 86 First flow path 86a Inlet opening 86b Inlet flow path 86c First flow Road body 87 Second flow path 87a Outlet opening 88 Connection flow path

Claims (9)

In the gas turbine tail cylinder seal that seals between the transition tube of the combustor and the inner shroud and the outer shroud of the first stationary blade stage downstream of the transition tube in the flow direction of the combustion gas,
In the wall portion along the combustion gas flow path, the air flow passage is formed along the wall surface facing the combustion gas flow path, and the air flowing in from the vehicle interior outside the combustion gas flow path flows to the downstream side in the wall portion. A first flow path;
In the wall portion, the air that is perpendicular to the flow direction of the combustion gas and that is adjacent to the first flow path in the circumferential direction along the wall surface, and the air that flows through the first flow path is burned in the wall section. A second flow path that flows upstream in the gas flow direction;
A cooling channel including a connection channel formed in the wall and connected to connect the downstream side of the first channel and the second channel so as to be folded back,
The first flow path has an inlet opening that communicates with the passenger compartment on the upstream side of the wall,
The gas turbine tail cylinder seal, wherein the second flow path has an outlet opening that communicates with the combustion gas flow path at the wall surface of the wall.   2. The gas turbine tail cylinder seal according to claim 1, wherein the outlet opening is disposed between the two adjacent first flow paths on the downstream side of the inlet opening.   3. The gas turbine tail cylinder seal according to claim 1, wherein the outlet opening is disposed on the downstream side of the inlet opening and in proximity to the inlet opening. 4. The first flow path includes a first flow path body that extends along the wall surface, and an inlet flow path that extends from the inlet opening to the combustion gas flow path side and is connected to the first flow path body in the vicinity of the wall surface. ,
The gas turbine tail cylinder seal according to any one of claims 1 to 3, wherein the inlet channel and the outlet opening are close to each other.   The gas turbine tail cylinder seal according to any one of claims 1 to 4, wherein a plurality of the cooling flow paths are formed so as to be aligned in the circumferential direction.   The gas turbine tail according to any one of claims 1 to 5, wherein the connection flow path extends in the circumferential direction and communicates the first flow path and the second flow path of the plurality of cooling flow paths. Tube seal.   The gas turbine tail cylinder seal according to any one of claims 1 to 6, wherein the outlet opening portion opens at an upstream end portion of the wall surface and functions as a film cooling hole of the wall surface.   The gas turbine tail cylinder seal according to any one of claims 1 to 7, wherein the connection flow path is impingement cooled to cool an inner wall surface by collision of air flowing through the first flow path. .   A gas turbine tail cylinder seal according to any one of claims 1 to 8, a combustor including the tail cylinder, and a turbine driven by combustion gas generated by the combustor. gas turbine.

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