JPH06108802A - Moving blade - Google Patents

Abstract

PURPOSE:To prevent generation of cracking on the root part of a blade profile part rear edge. CONSTITUTION:In a moving blade 6 provided in such constitution that each groove is provided on platform parts 14, 15 and a seal pin 13 is fitted in the groove so as to prevent high temperature gas from flowing in a shank part 11 through a clearance between moving blades 6 located adjacently to each other, the platforms 14, 15 are constituted by dividing them into two layers of the upper platform 14 for forming a gas path in relation to high temperature gas and a lower platform 15 in which the seal pin 13 is fitted by providing the groove.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving blade applied to a gas turbine, a jet engine and the like.

[0002]

2. Description of the Related Art FIG. 2 is an explanatory view of a general gas turbine,
FIG. 3 is an explanatory diagram of a moving blade of a conventional gas turbine. In the figure, generally, in a gas turbine, air is compressed by a compressor 1, fuel is injected into the compressed air by a combustor 2 to create combustion gas, and the combustion gas is introduced into a turbine unit 3 and rotated. It drives the generator 4 and the like. The turbine unit 3 is composed of a stationary blade 5 and a moving blade 6, etc. The moving blade 6 receives the high temperature gas from the combustor 2 via the stationary blade 5 and rotates the disk 8. This moving blade 6
Is composed of a blade profile portion 9 exposed to high temperature gas, a platform portion 10 forming a gas path, a shank portion 11 for attaching the moving blade 6 to the disk 8, a blade root 12, and the like. A groove is provided in the platform portion 10 in order to prevent it from flowing into the shank portion 11 through the gap between the moving blades 6 adjacent to each other, and the seal pin 13 is fitted in the groove.

[0003]

As described above, in the conventional blade of the gas turbine, the high temperature gas is the shank portion 1.
1 has a groove formed in the platform portion 10 to prevent it from flowing into the groove 1, and the seal pin 13 is fitted in the groove, so that the platform portion 10 has a large plate thickness. For this reason, a very large temperature difference occurs between the blade profile portion 9 and the platform portion 10 at the time of starting and stopping the gas turbine, and the thermal stress caused by this temperature difference is repeatedly received, so that the trailing edge of the blade profile portion 9 is damaged. Cracks may occur at the base.

[0004]

SUMMARY OF THE INVENTION A moving blade according to the present invention is intended to solve the above-mentioned problems, and a hot blade is provided on a platform portion so as not to flow into a shank portion through a gap between adjacent moving blades. In a moving blade in which a groove is provided and a seal pin is fitted in the groove, the platform portion is doubled in an upper platform that forms a gas path for the high-temperature gas and a lower platform in which the groove is provided and the seal pin is fitted. It is characterized in that it is provided separately.

[0005]

In other words, in the rotor blade according to the present invention, a groove is provided in the platform portion so that the hot gas does not flow into the shank portion through the gap between the rotor blades adjacent to each other, and the seal pin is fitted into the groove. The platform part of the blade is divided into an upper platform that forms a gas path for high-temperature gas and a lower platform that has a groove and is fitted with a seal pin.The upper platform that forms the gas path has a conventional thickness. The thickness of the platform can be made thinner than that of the above platform, and the temperature difference between the blade profile part and the upper platform part at the time of starting and stopping the gas turbine is reduced, and the thermal stress due to this temperature difference is reduced. It

[0006]

1 is an explanatory view of a rotor blade of a gas turbine according to an embodiment of the present invention. In the figure, the rotor blade of the gas turbine according to the present embodiment is a rotor blade of a gas turbine used for thermal power generation. Generally, the gas turbine compresses air with a compressor 1 as shown in FIG. Fuel is injected by the combustor 2 to generate combustion gas, and the combustion gas is introduced into the turbine unit 3 and rotated to drive the generator 4 and the like. The turbine unit 3 is shown in FIG.
As shown in FIG. 2, the stationary blade 5 and the moving blade 6 are configured to receive the high temperature gas from the combustor 2 via the stationary blade 5 and rotate the disk 8. As shown in FIG. 1B, the moving blade 6 has a blade profile portion 9 exposed to high temperature gas, a platform portion forming a gas path, a shank portion 11 for mounting the moving blade 6 on the disk 8, and a blade. It consists of roots 12, etc., and the platform part is 2
A lower platform 15 is provided below the upper platform 14 by dividing it into multiple layers. The upper platform 14 has a thin plate thickness, and the lower platform 15 allows hot gas to flow into the shank portion 11 through the gap between the moving blades 6 adjacent to each other. A groove is provided in order to prevent the seal pin 13
It has a structure that fits in.

When the platform portion has a large plate thickness like a moving blade of a conventional gas turbine, a very large temperature difference occurs between the blade profile portion and the platform portion at the time of starting and stopping the gas turbine. It is feared that cracks may occur at the root of the trailing edge of the blade profile portion 9 due to repeated thermal stress caused by this temperature difference, but in this moving blade, this platform portion forms a gas path for high temperature gas. The upper platform 14 and the lower platform 15 in which a groove is provided to prevent hot gas from flowing into the shank and the seal pin 13 is fitted in the groove are divided into a double platform structure to form a gas path. By reducing the plate thickness of the upper platform 14, the blade profile at the time of starting and stopping the gas turbine 9 and the upper platform 14 can be greatly reduced in temperature difference as compared with a conventional gas turbine moving blade, and thermal stress due to this temperature difference can be reduced to reduce the root of the trailing edge of the blade profile portion 9. The occurrence of cracks in the part is prevented. Further, since the disk 8 and the blade root 12 cannot withstand the strength at high temperature, a groove is formed in the lower platform 15 as in the case of a conventional gas turbine moving blade, and the seal pin 13 is fitted in the groove to increase the temperature. The gas is prevented from flowing into the shank portion 11 through the gap between the moving blades adjacent to each other. Since the root portion of the lower platform 15 is not exposed to the high temperature gas, a large temperature difference does not occur between the root portion and the shank portion 11, and the thermal stress is small.

[0008]

The rotor blade according to the present invention is configured as described above, and the temperature difference generated between the blade profile portion and the upper platform portion at the time of starting and stopping the gas turbine is reduced, and this temperature is reduced. Since the thermal stress due to the difference is reduced, cracks do not occur at the root of the trailing edge of the blade profile.

[Brief description of drawings]

FIG. 1 (a) is a front view of a rotor blade of a gas turbine according to an embodiment of the present invention, and FIG. 1 (b) is a perspective view thereof.

FIG. 2 is a schematic diagram of a general gas turbine.

FIG. 3 (a) is a front view of a moving blade of a conventional gas turbine, and FIG. 3 (b) is a perspective view thereof.

[Explanation of symbols]

 1 Compressor 2 Combustor 3 Turbine 4 Generator 5 Stator blade 6 Moving blade 7 High-temperature gas 8 Disk 9 Blade profile part 11 Shank part 12 Blade root 13 Seal pin 14 Upper platform 15 Lower platform

Claims (1)

[Claims] 1. A moving blade in which a groove is provided in a platform portion and a seal pin is fitted in the groove so that high-temperature gas does not flow into a shank portion through a gap between the moving blades adjacent to each other, A moving blade characterized by being provided in two parts, an upper platform that forms a gas path for high-temperature gas and a lower platform that is provided with the groove and is fitted with the seal pin.