JP3233752B2 - Air-cooled blade of gas turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air-cooled blade of a gas turbine applied to thermal power generation and the like.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view of an air-cooled blade of a conventional gas turbine used for thermal power generation or the like. In the figure, in order to cool a moving blade 3 of a gas turbine, air having cooled the inside of the moving blade 3 is blown out of a blade from a blowout hole 1 formed in a trailing edge side of a passage 6 on a blade rear side, and a blade surface is blown. Blow-off cooling is performed. A passage 6 through which cooling air flows is formed by bending a partition wall 7 inside the rotor blade 3, and an inner surface of the passage 6 is provided with a cooling air passage for improving the heat transfer coefficient and enhancing the cooling performance. A plurality of turbulators (turbulence promoters) 4 are arranged orthogonal to the flow. Also, a number of pin fins 5 project from the inner surface of the passage at the trailing edge of the bucket 3. The cooling air in the passage 6 that has cooled the inside of the moving blade 3 is blown out from the blowout hole 1 toward the blade surface, and forms a film of cooling air on the blade surface to perform blowing cooling of the blade surface. Each of the blowout holes 1 is a wing of a passage 6 in the middle of the turbulator 4 adjacent to each other.
It is located on the rear edge side angle.

[0003]

In the conventional air-cooled blade of a gas turbine as described above, when air having cooled the inside of the moving blade 3 is blown out of the blade to perform blow-off cooling of the blade surface, a blow-off hole is required. It is necessary to ensure a sufficient pressure difference between the inside and the outside of 1. However, since the turbulators 4 are arranged orthogonal to the flow of the cooling air, the pressure loss due to the turbulators 4 is large, and a sufficient pressure difference between the inside and the outside of the blowout hole 1 cannot be secured. Therefore, the effect of blowing and cooling the blade surface is weak.

[0004]

Air cooling vanes of a gas turbine according to the present invention, in order to solve the problem] is the purpose of solving the above problems, the wing internal
Of the cooling gas passage cooling blade cooling air through the provided with outlets in the blade trailing edge side of the gas turbine and then blowing out wings, the inner surface blade trailing edge turbulators in the cooling gas passage wing leading Of the cooling gas passage above the edge
It is characterized in that it is arranged with a gradient downstream .

[0005]

That is, in the air-cooling blade of the gas turbine according to the present invention, the air-cooling of the gas turbine in which the cooling gas is blown out of the blade through the blowing hole provided on the trailing edge side of the cooling gas passage inside the blade. A turbulator is provided on the inner surface of the cooling gas passage on the blade so that the cooling gas flows on the trailing edge side more than on the blade leading edge side.
The turbulator is disposed at such a gradient as to be downstream of the road, and the turbulator is disposed at such a gradient, so that the cooling gas generates a swirling secondary flow along the diagonal turbulator. locally pressure increases at the blade trailing edge side of the passage hole blowing by the following flow is provided. As a result, a sufficient pressure difference between the inside and the outside of the outlet is ensured.

[0006]

1 and 2 are explanatory views of an air-cooled blade of a gas turbine according to one embodiment of the present invention. In the figure, an air-cooled blade of a gas turbine according to the present embodiment is an air-cooled blade of a gas turbine used for thermal power generation or the like, and as shown in FIG. The blown air is cooled by blowing the cooled air to the outside of the wing from the blowing hole 1 formed on the trailing edge side of the passage 6 to cool the wing surface. A passage 6 through which cooling air flows is bent by a partition wall inside the moving blade 3. The trailing edge side of the blade is provided on the inner surface of the passage 6 in order to improve heat transfer coefficient and enhance cooling performance. So that it is downstream of the passage 6 from the leading edge
A plurality of turbulators (turbulence promoters) 2 are provided. In addition, a number of pin fins project from the inner surface of the passage 6 at the trailing edge of the rotor blade 3. The cooling air in the passage 6 that has cooled the inside of the moving blade 3 is blown out from the blowing hole 1 toward the blade surface, and forms a film of cooling air on the blade surface to perform blow-off cooling of the blade surface.
The blowout hole 1 is located on the blade trailing edge side angle of the passage 6 in the adjacent turbulators 2 intermediate each other.

[0007] In the air-cooled blades of this gas turbine, FIG 2
As shown in the figure , the turbulator 2 is provided on the inner surface of the cooling air passage 6 so that the trailing edge of the blade is located downstream of the passage 6 from the leading edge of the blade.
45 ° to 60 ° with respect to the direction perpendicular to the passage 6
It is arranged with a slope. Outlets 1 cooling air is pierced wing trailing edge side of the passage 6 to flow along the blade surface is blown from the inside passage 6. Thus, the turbulator 2 is positioned such that the trailing edge side of the blade is downstream of the passage 6 from the leading edge side of the blade.
By which is disposed with a slope so that the resulting secondary flow swirl of the cooling air along the oblique turbulators 2, after blade passage 6 by the dynamic pressure due to the secondary flow
The pressure of the cooling air locally increases near the entrance of the blowout hole 1 formed on the edge side . Thereby, the blowing hole 1
A sufficient pressure difference between the inside and the outside can be ensured. In addition, if the turbulator 2 is the trailing edge side of the wing,
When the cooling air is disposed so as to be more upstream than the passage 6, a locally high pressure point in the flow of the cooling air is opposite to the blowout hole 1 formed in the trailing edge side of the passage 6. At the position of the blow-out hole 1, the suction action works,
There is a danger that the hot gas outside the moving blade 3 will flow back inside the moving blade 3 and damage the moving blade 3.

[0008] In the case of blowing air cooled inside the moving blade to the outside of the blade to cool the blade surface, it is necessary to ensure a sufficient pressure difference between the inside and the outside of the blowing hole. However, in conventional air-cooled blades of gas turbines, the turbulators are arranged orthogonally to the flow of cooling air, so that the pressure loss due to the turbulators is large, secondary flow hardly occurs, and the inside and outside of the blow-out hole are not generated. And the pressure difference cannot be sufficiently secured. Therefore, although the effect of the blow-off cooling of the blade surface is weak, in the air-cooled blade of the present gas turbine, the turbulator 2 is arranged such that the trailing edge of the blade is downstream of the passage 6 from the leading edge of the blade.
The cooling air is swirled so that a secondary flow is generated, and the cooling air is pierced on the trailing edge side of the blade.
The pressure of the cooling air locally increases in the vicinity of the inlet of the blow-off hole 1 that is formed . Thereby, a sufficient pressure difference between the inside and the outside of the blowing hole 1 is ensured, and the cooling performance of the moving blade 3 is improved.

[0009]

The air-cooled blade of the gas turbine according to the present invention is constructed as described above, and a sufficient pressure difference between the inside and the outside of the blow-out hole is ensured, so that the effect of blow-off cooling of the blade surface is improved. improves.

[Brief description of the drawings]

FIG. 1A is a perspective view of an air cooling blade of a gas turbine according to one embodiment of the present invention, FIG. 1B is a cross-sectional view of the passage, and FIG. 1C is FIG. FIG.

FIG. 2 is an explanatory diagram of the operation.

3 (a) is a longitudinal sectional view of an air-cooling blade of a conventional gas turbine, FIG. 3 (b) is a sectional view taken along line BB in FIG. 3 (a), and FIG. (D) is a cross-sectional view taken along line DD in FIG. (C).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blow-out hole 2 Turbulator 3 Moving blade 6 Passage

Continuation of front page (56) References JP-A-2-223602 (JP, A) JP-A-5-179902 (JP, A) JP-A-1-10101 (JP, A) JP-A-5-163959 (JP) , A) JP-A-2-23201 (JP, A) JP-A-5-156901 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01D 5/18 F01D 9/00

Claims (1)

(57) [Claims] An air-cooling blade of a gas turbine for blowing a cooling gas out of a blade through a blowing hole provided on a trailing edge side of a cooling gas passage inside the blade, wherein a turbulator is provided on an inner surface of the cooling gas passage. The trailing edge side is more than the leading edge side
An air-cooled blade for a gas turbine, wherein the air-cooled blade is provided with a gradient downstream of the cooling gas passage .