JPH10317908A - Gas turbine stator blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate inconveniences such as the breakage of a fixing portion of a seal tube to a gas turbine stator blade of a recovery steam cooling type or the seal tube, in which the seal tube for supplying sealing air is disposed inside the blade. SOLUTION: A seal tube 13, which is inserted in a blade width direction inside of a gas turbine stator blade 1 of a recovery steam cooling type and is adapted to introduce and supply sealing air SA to be injected into a cavity formed between the peripheral surface of a rotor disk and the inner circumference of the blade 1 from the outer periphery of the blade 1, is fixed in the inside of the blade 1 via a bellows structure 20. Consequently, even if a difference in thermal extension occurs between the seal tube 13 and members O2, O3, O7 of the gas turbine stator blade 1, the deformation of the bellows structure 20 can absorb the difference, thus preventing any inconvenience which has been experienced in a conventional gas turbine stator blade.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of introducing steam into a blade, cooling the blade with the steam from the inside, and reducing the steam used for cooling the blade in order to prevent a reduction in plant efficiency. In connection with the gas turbine vane that was to be recovered,
In particular, two stages of turbines installed between the front and rear blades, three stages,
Four-stage: high-temperature mainstream gas flows into a gap formed between the outer peripheral surfaces of the rotor blades and the rotor disk before and after rotation, such as a gas turbine stationary blade, and the inner periphery of the stationary stationary blade. The present invention relates to a gas turbine stationary blade provided with a cavity portion for supplying seal air so as not to flow into the inner peripheral side.

[0002]

2. Description of the Related Art In recent years, in a combined cycle power plant, in order to improve the thermal efficiency of a gas turbine, the temperature of a mainstream gas for driving the turbine is significantly increased, and a moving blade and a stationary blade operating in such a high-temperature mainstream gas are used. In order to maintain the structural strength at a temperature equal to or lower than the metal temperature, it is considered that these turbine blades are efficiently cooled with steam having a large heat capacity instead of air.

[0003] Moreover, the steam used for cooling the turbine blades is recovered without being released into the mainstream gas, and the cooling heat of the turbine blades recovered by the recovered steam is recovered by a steam turbine. It is considered that the efficiency of the entire plant is improved by improving the efficiency of the turbine and suppressing the decrease in the temperature of the mainstream gas due to the release of steam into the mainstream gas. Therefore, in such a turbine blade, in order to recover the steam used for cooling, the turbine blade is provided inside and outside the shroud provided on the inner and outer sides of the blade and the blade portion,
It is necessary to form a cooling passage for cooling by passing steam through a closed flow passage.

On the other hand, gas turbine stationary blades used as turbine two-stage, three-stage, four-stage stationary blades and the like have a structure sandwiched between moving blades arranged in front and rear and a rotor disk on which the moving blades are implanted. In order to improve turbine efficiency, it is important to have a structure in which the mainstream gas does not flow into the gaps between the stationary vanes and the rotating blades and the rotor disk. Normally, air extracted from the compressor is supplied from the outer peripheral side of the stator vane to the inside of the vane, and supplied as seal air to cavities provided on the inner peripheral side of the vane, and seal air is supplied from the cavity to gaps between these parts. Thus, a structure is employed to prevent the mainstream gas from flowing into the gap.

FIG. 3 shows a conventional recovery-type steam-cooled type in which steam is introduced into the interior of the stationary blade, the stationary blade is cooled from the interior, and all of the cooled steam is recovered as described above. The seal air is supplied to the internal cooling structure of the gas turbine stationary blade and the cavity provided on the inner peripheral side of the stationary blade to supply the seal air to the gap formed between the stationary blade, the moving blade, and the rotor disk. FIG. 4 is a longitudinal sectional view showing a seal tube mounting structure provided in the gas turbine vane for introducing seal air from the outer peripheral side of the gas turbine vane.

[0006] As shown in the figure, cooling steam S introduced into the gas turbine stationary blade 01 and cooling the gas turbine stationary blade 01 from the inside is supplied to an outer shroud 03 provided on the outer peripheral side of the gas turbine stationary blade 01. Outer partition plate 06 on the leading edge side of
Through the cooling steam inlet 05 provided through the
Before provided spanwise supplied to the steam passage ₀₄ of the edge.

[0007] The cooling steam S supplied to the steam passage 04 ₁ on the leading edge side flows in the steam passage 04 ₁ from the outer peripheral side to the inner peripheral side, is defined in the inner shroud 07, and is formed by the inner partition plate 08. After flowing into the partitioned section, the direction of the flow is changed by 180 ° and is divided by the cooling passage wall 09, and the steam passage 04 ₂ provided behind the leading-edge steam passage 04 ₁ is moved from the inner peripheral side to the outer peripheral side. It flows toward the side, and then, flows toward the inside of the steam passage 04 ₃ which is defined in the rear from the outer peripheral side to the outer peripheral side,
Finally the steam passage 04 ₄ provided in the trailing edge flow from the inner to the outer circumferential side.

As described above, while the cooling steam S flows through the so-called serpentine-like steam passage 4 reciprocating in the blade portion 02 two times in the blade width direction, the cooling steam S of the gas turbine stationary blades 01 including the blade portion 02 is formed. Cool the whole from inside. And
Flows toward the steam passage ₀₄ of the trailing edge from the inner to the outer circumferential side, the cooling steam S that has cooled the trailing edge side of the gas turbine stationary blade 01, through the outer partition plate 06 in the trailing edge side of the outer shroud 03 The gas is discharged from the gas turbine stationary blade 01 through a cooling steam outlet 010 provided.

In such a gas turbine stationary blade 01, a gas turbine stationary blade 01 used as a two-stage, three-stage or four-stage stationary blade, as shown in FIG. 012, and the gaps between the stationary gas turbine stationary blades 01, the rotating blades 011, and the rotor disk 012, in other words, the gaps that need to be provided, It is important for the turbine efficiency to have a structure in which the high-temperature mainstream gas F does not flow in. Generally, as shown in FIG.
The bleed air from the compressor (not shown), through the seal tube 013 which is provided to penetrate from the outer peripheral side of the gas turbine stationary blade 01 through the steam path 04 _{and second} wing portions 02 in the spanwise direction, it is formed on the inner circumferential blade side In this case, a structure for supplying the air as seal air SA into the cavity portion 014 is adopted.

Then, as shown in FIG. 4, the seal air SA supplied into the cavity portion 014 is provided on the inner peripheral side of the cavity portion 014 with a seal supply passage 015 formed so that the front is directed in the axial direction. Through the gas turbine vane 0
1 and the outer peripheral surface of the rotor disk 012,
The turbine efficiency is improved by preventing high-temperature mainstream gas F from flowing into a gap formed between the stationary gas turbine stationary blade 01, the rotating blade 011, and the rotor disk 012.

On the other hand, the seal tube 013 provided to penetrate the wing portion 02 in the wing width direction is welded to the inner partition plate 08 whose tip portion is stretched in a section defined in the inner shroud 07. And the outer shroud 03
The penetration part of the outer partition plate 06 stretched in the section defined inside is welded to the outer partition plate 06, and the steam passage 04
And is fixed inside the gas turbine stationary blade 01.

As described above, the conventional gas turbine stationary blade 01
Then, the seal tube 013 for supplying the seal air SA
Is welded at the joint 016 between the inner partition plate 08 of the inner shroud 07 and the outer partition plate 06 of the outer shroud 03, joined to the gas turbine stationary blade 01, and cut off from the steam passage 04. Part 02, inner shroud 07, and outer shroud 03 and seal tube 0
13, a thermal stress is generated due to a difference in thermal elongation caused by a temperature difference, and the thermal stress may be damaged.

That is, taking the gas turbine stationary blade 01 used as a two-stage stationary blade as an example, the blade portion 02
And cooled by the cooling steam S to about 800
Kept at ° C. On the other hand, the sealing tube 013 is in contact with the outer peripheral surface and inner peripheral surface cooling steam S and sealing air SA flowing through the steam passage 04 ₂ is about 400 ° C..

Due to this temperature difference, the seal tube 013
Tends to cause a thermal expansion difference in the radial direction, but as described above, the leading end is attached to the inner partition plate 08 and the outer partition plate 0
6 is fixed to the outer partition plate 06 by a welded structure, so that the elongation is prevented, and the joint 016 has approximately 100 kg / mm ^2.
Is generated, and when this stress is repeated, the joint 016 is formed.
Of the seal tube 013 and buckling of the seal tube 013.

[0015]

SUMMARY OF THE INVENTION The present invention is provided between an inner peripheral side of a gas turbine stationary blade and a rotor disk in order to solve the above-mentioned problem that has occurred in the conventional gas turbine stationary blade. The seal tube that supplies sealing air to the cavity is attached to the blade using a bellows structure, so that the steam passage formed inside the blade and the seal air passage formed inside the seal tube are shut off. In addition, even if a large temperature difference may occur between the seal tube and the gas turbine stationary blades such as the blade portion, the inner shroud, and the outer shroud, the temperature difference may cause the joining between the seal tube and the blade. An object of the present invention is to provide a gas turbine vane in which breakage of a portion or breakage such as buckling of a seal tube does not occur.

[0016]

Therefore, the gas turbine stationary blade of the present invention has the following means.

(1) A recovery-type steam-cooled gas turbine vane in which the blades are cooled from the inside by the steam introduced into the blades, and the steam used for cooling is discharged to the outside and recovered. The inside is inserted in the blade width direction, and into the cavity formed between the rotor disk outer peripheral surface and the blade inner circumference,
A seal air to be injected into the gap formed between the gas turbine stationary blade and the rotor blade and the rotor disk to prevent the mainstream gas from entering is introduced from the blade outer peripheral side and supplied. The sealed tube was attached to the wing via a bellows structure. In the bellows structure, the seal tube inserted in the blade width direction may be arranged so as to be able to be joined at any place of the gas turbine stationary blade, for example, at the blade part.

(A) In the gas turbine stationary blade of the present invention, a large temperature difference is generated between the seal tube and the blade portion, the inner shroud, the outer shroud, and the like constituting the gas turbine stationary blade by the configuration described above. Even if there is a difference in thermal expansion in the width direction of the gas turbine vane between the two, this difference in thermal expansion is absorbed by the deformation of the bellows structure, and the joint between the seal tube and the gas turbine vane No excessive thermal stress is generated in the joint, and the joint is not broken. Furthermore, the displacement between the joints does not deform the seal tube, which prevents buckling.

Further, since the seal tube is attached to the blade via the bellows structure, separation between the steam passage formed inside the blade and the seal air passage formed inside the seal tube is facilitated. Further, the cooling steam flowing through the steam passage does not mix with the seal air and flow out into the mainstream gas.

Further, the gas turbine stationary blade of the present invention employs the following means in addition to the above-mentioned means (1).

(2) The bellows structure in the above-mentioned means (1) is provided on at least one of the outer shroud provided on the outer peripheral side of the gas turbine stationary blade and the inner shroud provided on the inner peripheral side of the blade. The seal tube was attached to the wing. That is, the bellows structure may be provided on both the outer shroud and the inner shroud to attach the seal tube to the wing, or may be provided on either the outer shroud or the inner shroud to attach the seal tube to the wing. You may do it.

In the bellows structure, a steam passage is defined in an inner circumferential side of a penetration portion of an inner partition plate formed by defining a steam passage in the inner shroud and / or in an outer shroud through which the seal tube passes. It is preferable to connect one end to the outer peripheral side of the penetrating portion of the outer partition plate formed as described above.

In the gas turbine vane of the present invention, in addition to the above configuration (a), the bellows structure can be arranged by reducing interference with the steam passage formed inside the gas turbine vane. Thus, the bellows structure can be compactly arranged in a narrow portion. Further, if the bellows structure is provided on both the outer shroud and the inner shroud, the displacement and the force applied to the bellows structure are reduced to almost 、, the compactness can be reduced, and the installation in a narrow portion is more preferable. It becomes something.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas turbine vane according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of a gas turbine stationary blade according to the present invention. In the drawing, the same or similar members as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in the figure, a gas turbine static gas turbine having a seal tube 13 penetrating through a steam passage 04 formed in a recovery-type steam-cooled gas turbine stationary blade 1 of the present embodiment in the blade width direction. Attach to wing 1 with outer shroud 0
The joint 16 on the third side is connected by using an elastic bellows structure 20 to block the inside of the seal tube 13 through which the seal air SA passes from the steam passage 04. That is, a steam passage defined inside the outer shroud 03 is defined and formed, and the cooling steam inlet 0
5 is provided with a hole 21 through which the seal tube 13 is slidably penetrated in the outer partition plate 06 provided with a cooling steam outlet 010 on the trailing edge side.

On the outer peripheral side of the hole 21, a bellows structure 20 is provided.
One end side is welded and the bellows structure 20
Is connected to the seal tube 13 by a flange 23 which is bolted to a flange 22 attached to the outer periphery of the seal tube 13 above the hole 21. The seal tube 13 is composed of a bellows structure 20 and an outer partition plate. 06, and is joined to the outer shroud 03. On the other hand, the distal end of the seal tube 13 formed by partitioning the steam passage defined inside the inner shroud 07 and penetrating the inner partition plate 08 serving as the partition wall of the cavity 014 is welded as in the conventional case. Is joined to the inner partition plate 08 at the joined portion 016, and is fixed to the inner shroud 07 via the inner partition plate 08.

With this structure, the steam flows through the steam passage 04,
The cooling steam S for cooling the gas turbine vanes 1 from the inside is prevented from leaking out of the vanes, and the gas turbine vanes 1 including the blade portions 02, the outer shroud 03, the inner shroud 07, and the like, and the seal tube 13 The thermal expansion difference generated in the spanwise direction caused by the temperature difference can be absorbed by the expansion and contraction of the bellows structure 20, and the thermal stress that may have been concentrated on the joints 16, 016 can be reduced.
It is possible to prevent the occurrence of breakage which may occur in the above.

The seal tube 13 is connected to the joint 16,
The displacement of 016 does not cause breakage such as buckling. Further, since the bellows structure 20 is provided on the outer peripheral side of the outer partition plate 016, the bellows structure 20 does not interfere with the steam passage 04, so that cooling from the inside of the blade is not impaired, and there is a margin in space. It can be arranged compactly in a narrow part with few.

FIG. 2 is a sectional view showing a second embodiment of the gas turbine stationary blade according to the present invention. In the figure, the same or similar members as those shown in FIG.
As in the embodiment, the same reference numerals as those in FIG.

As shown in the figure, in the recovery type steam-cooled gas turbine vane 1 of the present embodiment, in addition to the first embodiment, a steam passage defined inside the inner shroud 07 is defined. And a seal tube 1 formed through an inner partition plate 08 serving as a partition wall of the cavity portion 014.
3 has a bellows structure 2 similar to the bellows structure 20.
4 was attached to the inner partition plate 08 in the same manner as the bellows structure 20.

Thus, in the gas turbine stationary blade 1 of the present embodiment, the displacement and the force applied to the bellows structures 20 and 24 are １ ／ of those of the first embodiment in which only the bellows structure 20 is provided. In consideration of the fact that this kind of seal tube 13 is installed in a narrow portion, the structure becomes compact and the configuration becomes extremely convenient for installation.

[0032]

As described above, according to the gas turbine vane of the present invention, the inside of the recovery type steam-cooled gas turbine vane is inserted in the blade width direction, and the outer peripheral surface of the rotor disk and the inner periphery of the blade are removed. A seal tube to be introduced and supplied from the outer periphery of the blade into the cavity formed in the cavity formed between the blade member and the sealing member is attached to the blade via a bellows structure.

As a result, even if a large temperature difference occurs between the seal tube and the gas turbine stationary blade, and a difference in thermal expansion in the blade width direction of the gas turbine stationary blade occurs between the two, This difference in thermal expansion is absorbed by the deformation of the bellows structure, so that excessive thermal stress does not occur at the joint between the seal tube and the gas turbine vane, so that the joint does not break, and the joint does not break. The displacement between them prevents the seal tube from deforming and causing buckling.

Further, separation between the steam passage formed inside the blade and the seal air passage formed inside the seal tube is facilitated, and the cooling steam flowing through the steam passage mixes with the seal air to form a mainstream gas. Eliminating the inflow does not improve the thermal efficiency of the product and ensures reliability.

In the gas turbine stationary blade according to the present invention, the bellows structure is provided on at least one of an outer shroud provided on an outer peripheral side of the gas turbine stationary blade and an inner shroud provided on an inner peripheral side of the blade. The seal tube is mounted inside the gas turbine stationary blade.

Thus, the bellows structure can be arranged with less interference with the steam passage formed inside the gas turbine stationary blade, and the bellows structure can be compactly arranged in a narrow portion. If the bellows structure is provided on both the outer shroud and the inner shroud, the displacement and the force applied to the bellows structure are halved, so that they can be more compactly assembled and are suitable for installation in a narrow portion.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a gas turbine vane according to the present invention;

FIG. 2 is a sectional view showing a second embodiment of the gas turbine vane according to the present invention;

FIG. 3 is a sectional view showing a conventional gas turbine stationary blade;

FIG. 4 is a layout view of a gas turbine stationary blade installed between moving blades to which the gas turbine stationary blade of the present invention is suitably applied.

[Explanation of symbols]

1,01 Gas turbine stationary blade 02 blade portion 03 outer shroud 04,04 _1, 04 _2, 04 _3, 04 ₄ steam passage 05 cooling steam inlet 06 outside the partition plate 07 inside the shroud 08 inside the partition plate 09 cooling passage wall 010 cooling steam Outlet 011 Rotating blade 012 Rotor disk 13,013 Seal tube 014 Cavity part 015 Seal supply path 16,016 Joint 20 Bellows structure 21 Hole 22,23 Flange 24 Bellows structure

Claims (2)

[Claims] 1. A gas turbine stationary blade configured to cool the blade from the inside with steam introduced into the blade, and discharge and collect the steam used for cooling to the outside. A seal tube inserted in the blade width direction and adapted to supply sealing air to a cavity formed on the inner peripheral side of the blade facing the outer peripheral surface of the rotor disk is provided inside the blade via a bellows structure. A gas turbine stationary blade attached to a gas turbine. 2. The bellows structure is provided on at least one of an outer shroud provided on an outer peripheral side of the wing and an inner shroud provided on an inner peripheral side of the wing, and the seal tube is provided inside the wing. The gas turbine vane according to claim 1, wherein the gas turbine vane is attached to a gas turbine.