JPH11287104A - Platform for gas turbine moving blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the cooling structure of the platform of a gas turbine moving blade for improving its cooling efficiency. SOLUTION: Cavities 2, 8 are provided in the platform 1 of a moving blade 51. In the cavities 2, 8, the inside of a plat form base part 10 is formed in a concave thin structure, and its lower part is covered with a bottom plate to form the cavity 2. In the cavity 2, portions 2a, 2b, 2c are formed in protruding parts 4, 5, and a portion 2d is opened toward a rear end. A protruding part 3 is protruded into the portion 2a, and a protruding part 6 is protruded into the portion 2b, and a protruding part 7 is protruded into the portion 2c to form a wave-shaped detour flow path. In addition, the cavity 8 is also composed of a portion 8a having a protruded protruding part 9, a linear portion 8b, a portion 8c on a rear end side and an opening portion 8d. A cooling air passes through cooling pathes 11, 32 from a flowing in port 11 and detouringly flows in the cavities 2, 8 and increases a cooling effect and flows out from a rear end face. A cooling route is formed of the cavity to improve a processability and to increase the cooling effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine rotor blade platform, which has improved cooling performance.

[0002]

2. Description of the Related Art FIG. 4 is an internal sectional view of a typical platform of a gas turbine moving blade, which is an example mainly used for a single-stage moving blade. In the figure, 50 is the entire platform, and 51 is a single stage rotor blade. 52 is a moving blade 5
The cooling passages 53 and 54 extending to both sides are provided in communication with the passage 52. The cooling passages 53 and 54 are respectively provided on the cooling passages 5 on both sides.
5 and 56, the passages 55 and 56 each being open at the rear end of the platform 50.

At the front end of the platform 50, cooling passages 57, 58 and 59, 60 are provided on both sides, respectively. The cooling passages 57 to 60 are formed by being inclined from the lower surface to the upper surface of the platform 50. It opens at the top and blows out cooling air.
The cooling passages 60, 6 are located behind the platform 50.
1,62 are drilled and the platform 5
0 is provided so as to be inclined from the lower surface toward the upper surface, is opened at the rear end, and blows out cooling air.

Further, cooling passages 64, 65, 66, 67, and 68 are provided at the center of the platform, and are similarly provided obliquely from the lower surface of the platform toward the upper surface so as to blow cooling air to the upper surface. The outlet end is formed in a divergent shape on the upper surface to diffuse cooling air.

FIG. 5 is a sectional view taken along the line DD in FIG.
Cooling passages 55 and 5 are provided inside both ends of the platform 50.
6, and shows a state where the cooling passage 67 is formed obliquely from the lower surface of the platform 50 toward the upper surface.

FIG. 6 is a sectional view taken along line EE in FIG.
The cooling passage 55 opens from the front to the back of the platform 50 and the cooling passages 57 and 64 provided diagonally.
68 are provided, and show a state in which the cooling air is blown back and to the upper surface, respectively.

In the platform 50 having the above-described structure, a part of the cooling air supplied from the leading edge passage 52 into the moving blade 51 flows through the cooling passages 55 and 56 so that the platform 5
0 Both sides are cooled and discharged to the rear of the platform 50, and the cooling passages 57-6
The cooling air is guided from the lower part of the platform 50 by flowing the cooling air from the lower part of the platform 50 to the upper surface around the front and rear ends. The liquid flows out from the lower part to the upper part. The entire platform 50 is cooled by the flow and outflow of the cooling air.

[0008]

As described above, in the conventional typical gas turbine blade platform, in addition to the linear main cooling passages of the cooling passages 55 and 56,
A large number of cooling passages 57-60, 61-63, etc., which penetrate the platform 50 obliquely and have a relatively long inclined route, are provided, there are many cooling air supply paths, and the processing of the platform itself becomes complicated. Facilitate and
In addition, the cooling effect has been desired to have a shape capable of uniformly cooling the entire platform.

Accordingly, the present invention provides a gas turbine which simplifies the path of the cooling air of the platform, simplifies the supply path of the cooling air to facilitate processing, and uniformly cools the entire platform to enhance the cooling effect. The task was to provide a platform for the moving blade.

[0010]

The present invention provides the following means (1) and (2) to solve the above-mentioned problems.

(1) A cooling air flow path which is provided on both sides of the blade base of the platform from the leading edge side to the trailing edge side, and has a concave inside inside the platform. Both side cavities formed so as to open at the end face, an inflow side cavity provided on the leading edge side of the platform, forming the inside of the platform in a concave shape and communicating with the both side cavities, and cooling air from the inside of the platform in the inflow side cavity. And a bottom plate that covers the concave openings of the inflow-side cavity and the two-sided cavity.

(2) In the invention of the above (1), the two-sided cavity and the inflow-side cavity are grooves having the same width, and the inflow port is a cooling passage at a leading edge in a moving blade. Bucket.

In the platform (1) of the present invention,
The cooling air enters the inflow-side cavity from the inflow port, cools the leading edge side, and flows into the two-sided cavity from the inflow-side cavity. Since the cooling air that has flowed into the cavities on both sides is a detour channel with a corrugated flow path in the cavities, the changed flow increases the heat transfer effect, effectively cooling both sides of the platform, and leak. The cavities on both sides and the inflow-side cavities have a shape in which the inside of the platform is processed into a concave shape. Making it easier. Therefore, there is no complicated flow path or inclined flow path as in the prior art, and the workability of the cavity and the platform itself is improved, and the cooling effect is increased.

In the platform (2) of the present invention,
The cavities on both sides and the inflow-side cavities are formed by grooves having the same width, and the inflow port of the cooling air is also a passage at the leading edge of the moving blade. Therefore, all processing of the cavities need only be grooves with the same width, and the lids may also be of the same width.
In the invention of the above (1), the workability is improved,
As for the cooling effect, the cooling air flow path is a detour,
As in (1), the cooling effect is increased.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1A and 1B show a platform of a gas turbine blade according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, and FIG.
It is -A sectional drawing.

In FIG. 1, reference numeral 1 denotes a platform, and 51 denotes a moving blade. Reference numeral 2 denotes a cavity in the platform 1, which is formed on the ventral side of the moving blade 51 by reducing the thickness of the portion near the center of the platform 1 in a concave shape as shown in FIG. 14 are provided.

The cavity 2 is formed so that the cavities 2a, 2b and 2c communicate with each other by protrusions 4 and 5 projecting from the periphery of the base 10 of the platform 1 from the leading edge to the trailing edge of the rotor blade 51. Has an opening with a linear 2d. In the cavity 2a, the base 1 on the blade 51 side is provided.
0, a projection 6 is provided in the cavity 2b.
However, the protrusions 7 protrude between the cavities 2c to form the cavities 2c.
, Or a S-shaped bypass flow path communicating therewith.

Similarly, a cavity 8 is provided on the back side of the moving blade 51 and is formed in the platform 1 like the cavity 2 so as to be concavely reduced in thickness, and is formed by closing the bottom with the bottom plate 14. I have. The cavity 8 is formed so as to communicate with 8a, a linear portion 8b, a detour portion 8c, and an opening 8d, and a projection 9 projecting from the base 10 enters the cavity 8a to form an S-shaped flow. Forming a road.

Reference numeral 11 denotes an inlet for cooling air provided through the bottom surface inside the platform 1, and the cooling air is guided from inside the platform 1. Numerals 12 and 13 denote cooling passages, and the same as the cavities 2 and 8, the platform 1
It is a passage that is formed to have a concavely reduced thickness inside and guides cooling air from the inlet 11 to the cavities 2 and 8 on both sides.

FIG. 2 is a sectional view taken along the line BB in FIG.
The inflow port 11 is open at the bottom of the central part, and the cooling air 70
And are provided to communicate with the left and right cooling passages 12 and 13. The cooling passages 12 and 13 are also hollow 2
Similarly to 8, the front edge of the platform 1 is formed with a reduced thickness at the peripheral end, and the bottom surface is covered with a bottom plate 14.

The bottom plate 14 may be provided separately from a portion covering the cooling passages 11 and 12, a portion covering the cavity 2, and a portion covering the cavity 8. Alternatively, the bottom plate 14 may be provided separately.
2, an integrally formed bottom plate that covers the cavity 2 and the cavity 8, and may have any shape.

In the platform having the above configuration, the cooling air 70 flows from the inside of the platform 1 to the inlet 11.
Through the cooling passages 12 and 13 to cool the leading edge of the platform and into the cavities 2 and 8.

The cavities 2 meander through the cavities 2a, 2b, and 2c formed by the projections 3, 4, 5, 6, and 7 to increase the heat transfer effect by convection. Through the rear end face.

Similarly, the cooling air flowing into the cavity 8 flows around the cavity 8a formed by the projection 9 at the front edge, and effectively cools the front edge by its convection. The narrow portion passes through the linear cavity 8b, cools the portion, flows around the trailing edge cavity 8c, and flows out of the rear end from 8d.

According to the platform of the first embodiment described above, the cavities 2 and 8 forming the corrugated or S-shaped bypass flow path are provided on both sides of the platform 1, and the inner bottom surfaces of the cavities 2 and 3 are formed. Cover with a bottom plate 14
The cooling air is guided into the inside of the platform 8 from the inflow port 11 through the cooling passages 11 and 12, so that the cooling air is guided to the front edge side of the platform 1 to cool this portion and to flow around both sides. This increases the heat transfer effect and cools both sides, so that the entire platform can be cooled uniformly.

Further, as described above, the cooling effect is increased, and the cooling passages of the platform 1 are all hollow cavities 2 and 8 and the cooling passages 11 and 8 forming recesses in which the base 10 is thinned.
Since it is composed of the base plate 12 and the bottom plate 14, the integral molding becomes easier and the processing becomes easier.

FIGS. 3A and 3B show a gas turbine rotor blade platform according to a second embodiment of the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along line CC in FIG. In the figure, 21 is a platform, 51 is a rotor blade, 5
Reference numeral 2 denotes a passage through which the cooling air of the moving blade 51 passes. 22,23
Are recessed cooling grooves of the same width provided on the back side (inside) of the platform 21. The cooling grooves have a corrugated or S-shaped bypass flow path as shown in FIG. And is provided continuously so as to open at the rear end face.

The cooling grooves 22 and 23 are provided such that one end thereof communicates with a passage 52 inside the rotor blade 51 and the other end is opened to the rear end. Also, as shown in FIG. 2B, the openings of the cooling grooves 22 and 23 are
Is inserted to cover the opening, and a cooling air flow path is formed.

The lids 24, 25 have a constant width slightly wider than the width of the cooling grooves 24, 25, and are formed with two-step grooves 22a, 23a along the cooling grooves 24, 25.
a, 23a to close the cooling grooves 24, 25 to form a cooling air flow path.

In the platform according to the second embodiment described above, the cooling air 70 flows in the cooling grooves 22, 23 meandering along the grooves from the passage 52 of the moving blade 51, respectively. From the rear end while cooling the entire surface from the rear edge to the rear edge.

Therefore, according to the platform of the second embodiment, similarly to the first embodiment, the cooling grooves 22, 23 and the lids 24, 25 through which the cooling air flows by bypassing.
Is provided, the entire platform is uniformly cooled, and the cooling system is also formed by processing the cooling grooves and closing the lid, thereby facilitating the processing. Further, the cooling grooves 22 and 23 have the same width and have a simple shape compared to the cavity of the first embodiment, and the groove width is small, so that the processing is easier than that of the first embodiment.

[0032]

The gas turbine moving blade platform of (1) of the present invention is a cooling air flow path provided on both sides of the moving blade base from the leading edge side to the trailing edge side, and the inside of the platform is formed in a concave shape. A two-sided cavity formed so as to bypass the flow path in a wave-like manner and open at a trailing edge side end surface, and an inflow formed on the leading edge side of the platform to form a concave inside of the platform and communicate with the two-sided cavity. It is characterized by comprising a side cavity, an inflow port for guiding cooling air from the inside of the platform to the inflow side cavity, and a bottom plate covering the concave openings of the inflow side cavity and the both side cavities. With such a configuration, the platform has a simple structure that covers the cavity and the opening of the cavity, so it is easy to integrally form the platform, workability is improved, and the cooling air bypasses and flows to increase the heat transfer effect, The cooling effect is also improved.

According to a second aspect of the present invention, in the first aspect of the present invention, the both side cavities and the inflow side cavities are grooves having the same width, and the inflow port is a cooling passage at the leading edge in the rotor blade. Because it is a feature, all cavities may be grooves of the same width,
In addition, this groove facilitates formation of a bypass flow path, further improves workability, and enhances a cooling effect.

[Brief description of the drawings]

FIG. 1 shows a platform of a gas turbine blade according to a first embodiment of the present invention, wherein (a) is a plan view and (b)
FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 2 is a sectional view taken along line BB in FIG.

FIGS. 3A and 3B show a gas turbine blade platform according to a second embodiment of the present invention, wherein FIG. 3A is a plan view and FIG.
FIG. 3 is a cross-sectional view taken along line CC in FIG.

FIG. 4 is a typical sectional view of a conventional gas turbine blade.

FIG. 5 is a sectional view taken along line DD in FIG. 4;

FIG. 6 is a sectional view taken along the line EE in FIG. 4;

[Explanation of symbols]

 1, 21 Platform 2, 8 Cavity 3, 4, 5, 6, 7, 9 Projection 10 Base 11 Inlet 12, 13, Cooling passage 14 Bottom plate 22, 23 Cooling groove 22a, 23a Groove 24, 25 Lid 51 Moving blade 52 Passage 70 Cooling air

Claims (2)

[Claims] 1. A cooling air flow path provided from both a leading edge side to a trailing edge side on both sides of a rotor blade base of a platform and having a concave inside inside the platform, the flow path being undulated in a wavy manner, and a trailing edge side end face. Both cavities formed so as to be opened at, an inflow-side cavity provided on the leading edge side of the platform and having the inside of the platform formed in a concave shape and communicating with the both-side cavities, and cooling air from the inside of the platform into the inflow-side cavity. A gas turbine rotor blade platform, comprising: an inflow inlet; and a bottom plate covering concave openings of the inflow-side cavity and both-side cavities. 2. The gas turbine moving blade according to claim 1, wherein the both-side cavity and the inflow-side cavity are grooves having the same width, and the inflow port is a cooling passage at a leading edge inside the moving blade.