JPH11336505A - Structure of contacting gas turbine stator blade with blade hoop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the deflection of a blade hoop caused by thermal expansion in a structure of contacting each stator blade of gas turbine with its blade hoop by reducing the area of contacting the stator blade with blade hoop, and thereby reducing the heat conducted from the stator blade to the blade hoop. SOLUTION: The outer shroud 2 of a stator blade 1 and a flange 5 on a blade hoop 4 contact with the contacting surface-(A) 7, where firm contacting is established and a large area has influence of the thermal conduction. At the peripheral surface of this part on the side with the flange 5, grooves 10 are furnished at a certain spacing. Because the contacting area is lessened by an amount corresponding to the area determined by the groove width and length and the number of them, the heat conducting area is decreased, which should suppress temp. rise on the blade hoop 4 to present it from being deflected by the thermal expansion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact structure between a gas turbine stator blade and a blade ring, and reduces heat transferred to the blade ring.
The temperature rise of the blade ring is suppressed, so that the deflection of the thermal expansion of the blade ring is reduced.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a blade ring portion of a conventional gas turbine stationary blade. In the drawing, reference numeral 1 denotes a stationary blade, 2 denotes an outer shroud thereof, and 3 denotes a tube for sealing air, which is provided so as to penetrate the inside of the blade from the outer shroud 2 inward. Reference numeral 4 denotes a blade ring, and reference numeral 5 denotes a blade ring flange, which supports the outer shroud 2 of the stationary blade 1 on the blade ring 4. The wing ring 4 and the wing ring flange 5 have an annular structure.
The blade ring flange 5 is engaged with the flange 6 of the outer shroud 2 to fix and support the outer shroud 2.

[0003] Reference numeral 7 denotes a contact surface (A).
And the outer peripheral surface of the outer shroud 2 in contact with the outer peripheral surface. 8 is a fitting portion. Reference numeral 9 denotes a fitting portion between the outer shroud 2 on the opposite side (the upstream side of the gas flow) and the blade ring 4, and has a structure in which the outer shroud 2 is supported by a block 10 attached to the blade ring 4 with bolts 11. From the viewpoint of reducing the heat transfer from the stationary blade 1 to the blade ring 4, the range is out of the scope of the present invention, and therefore, further description is omitted.

In the gas turbine stationary blade having the above-described structure, high-temperature combustion gas flows during operation of the gas turbine, and the stationary blade 1
Is heated to a high temperature, and the heat is also transmitted to the outer shroud 2. The outer shroud 2 is supported by the blade ring 4 at the front and rear by a blade ring flange 5 and a block 10. The outer shroud 2 comes into contact with the contact surface (A) 7 with the blade ring 4, and heat from the stator blade 1 is transferred to the blade ring 4. Reportedly.

[0005] Of the portion of the blade ring 4 that supports the outer shroud 2, the block 10 has a structure that is divided from the blade ring 4, and from the viewpoint of heat transfer, the blade ring flange 5 contacts the outer flange 2. The contact surface (A) 7 is the most problematic part, and it has been desired to take measures to reduce the heat transmitted from these contact surfaces to the blade ring 4 and minimize the temperature rise of the blade ring 4 as much as possible.

[0006]

As described above, in the conventional vanes of a gas turbine, the metal temperature of the vanes rises due to heat transfer from the vanes to the vanes, and the vanes become excessively thermally expanded. There is a risk of distortion, and it is necessary to prevent the temperature of the blade ring from rising as much as possible. In particular, the portion where the heat transfer to the blade ring 4 is large is the contact surface (A) 7 where the blade ring flange 5 and the outer flange 2 are in direct contact with each other. The outer shroud 2 has a small contact area and a small thickness, and is most susceptible to the heat transfer of the high-temperature gas flow. It is necessary to make such a portion less susceptible to heat transfer as much as possible and to have a shape that satisfies the strength.

Accordingly, the present invention provides a contact structure between a gas turbine stator blade and a blade ring which can reduce heat transfer at a joint portion with a blade ring supporting the stator blade and can prevent an increase in metal temperature of the blade ring. It is an object of the present invention to prevent the blade ring from bending due to excessive thermal expansion.

[0008]

The present invention provides the following means for solving the above-mentioned problems.

In the contact surface between the blade ring flange for supporting the outer shroud of the stationary blade and the outer peripheral surface of the outer shroud, the contact surface is arranged substantially in parallel to the surface on the blade ring flange side in the circumferential direction. And a contact structure between a gas turbine stator blade and a blade ring, wherein a plurality of grooves extending in an axial direction are formed.

[0010] The contact structure between the stator vane and the blade ring according to the present invention is characterized in that at the joint surface between the outer peripheral surface of the outer shroud and the blade ring flange,
Since a plurality of grooves are provided on the blade ring side, the contact area is reduced by the area determined by the width and length of the grooves and the number of grooves, and the heat transfer area is reduced. Therefore, the heat transferred from the outer shroud to the blade ring at this contact surface is reduced, the rise in metal temperature of the blade ring can be suppressed correspondingly, and the deflection due to the thermal expansion of the blade ring can be prevented.

[0011]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a partial sectional view of a contact structure of a gas turbine stationary blade according to an embodiment of the present invention. In the figure, reference numerals 1, 2, 4 to 8 are the same as those of the conventional example shown in FIG. 4, and therefore the same reference numerals are used as they are and detailed description is omitted. There.

In FIG. 1, a contact surface (A) 7 is a portion where the outer shroud 2 and the blade ring 4 are in direct contact, and is a portion most affected by heat transfer.

A plurality of rows of grooves 10 are formed in the contact surface (A) 7 substantially parallel to the peripheral surface. 2 is a sectional view taken along line XX of FIG. 1, and FIG. 3 is a partial perspective view of a contact surface (A) 7 of the blade ring flange 5. In both figures, grooves 10 are formed on the contact surface 10 of the blade ring flange 5 at a predetermined interval t on the entire peripheral surface. The grooves 10 are not necessarily parallel to each other, may be inclined with respect to each other, and the interval t may not be constant, but is preferably parallel from the viewpoint of workability.

When the groove 10 is provided on the contact surface (A) 7 of the blade ring 4, the area of the blade ring flange 5 in contact with the surface of the outer shroud 2 is reduced by an area determined by the length, width and number of the grooves 10. The contact area can be reduced accordingly. That is, in FIG. 2, if the length of the groove 10 is L, the groove width is d, and the total number of the grooves 10 is N, the contact area is reduced by LdN.

When the contact area on the contact surface (A) 7 decreases, the transmission area decreases, and accordingly, the amount of heat transmitted from the outer shroud 2 to the blade ring 4 decreases, and the thermal influence of the blade ring 4 can be reduced. The number, interval t, and width d of the grooves 10N are not particularly limited, and may be determined in consideration of the shape of the outer shroud 2, leakage of the high-temperature combustion gas, influence of strength, and the like. . Also, the cross-sectional shape of the groove 10 may be any shape such as a semicircle, a square, etc., but a semicircle or a gentle curved surface is preferable from the viewpoint of strength.

According to the embodiment described above, the plurality of grooves 10 are arranged in the circumferential direction on the blade ring flange 5 side of the contact surface (A) 7 between the outer shroud 2 of the stator blade 1 and the blade ring 4. The contact area between the outer shroud 2 and the blade ring flange 5 is reduced, and the heat transferred from the outer shroud 2 to the blade ring is reduced.
The rise in metal temperature of the blade ring 4 is suppressed. As a result, it is possible to prevent the blade ring from flexing due to excessive thermal expansion and to prevent generation of thermal stress that is unreasonable in terms of strength.

[0017]

According to the contact structure of the gas turbine stator blade and the blade ring of the present invention, the contact surface between the blade ring flange for supporting the outer shroud of the stator blade and the outer peripheral surface of the outer shroud is provided. It is characterized in that a plurality of grooves are arranged on the surface on the side of the blade ring flange in the circumferential direction so as to be substantially parallel to each other and extend in the axial direction. With such a structure, the contact area between the outer peripheral surface of the outer flange and the blade ring flange is reduced, the heat transferred from the outer shroud to the blade ring is reduced, the rise in metal temperature of the blade ring is suppressed, and the blade ring becomes excessive. It does not sag due to thermal expansion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a contact structure between a gas turbine vane and a blade ring according to an embodiment of the present invention.

FIG. 2 is a view taken along the line XX in FIG.

FIG. 3 is a perspective view of a blade ring portion of a gas turbine stator blade and blade ring contact structure according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional contact structure between a gas turbine stationary blade and a blade ring.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 stator blade 2 outer shroud 4 blade ring 5 blade ring flange 6 outer shroud flange 7 contact surface (A) 8 fitting portion 10 groove

Claims (1)

[Claims] At a contact surface between a blade ring flange supporting an outer shroud of a stator blade and an outer peripheral surface of the outer shroud, the contact surfaces are substantially parallel to each other in a circumferential direction with respect to a surface on the blade ring flange side of the contact surface. A contact structure between a gas turbine stator blade and a blade ring, wherein a plurality of grooves extending in an axial direction are formed and arranged.