JPH1193609A - Gas turbine stationery blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce heat stress of a blade caused by heat deformation of a shroud, in a stationary blade of a gas turbine formed as a bind blade structure. SOLUTION: A pin hole 11 extending in a tangential line is arranged on a split surface extending in an axial direction of shrouds 2, 2. A pin 6 having a large heat expansion coefficient is fitted to the pin hole 11 by the shrouds 2, 2, adjacent shrouds 2, 2 are connected to each other, and installing plates 5, 5 arranged along the split surface extending in the axial direction of the shrouds 2, 2 are connected to each other through a fastening member 7 on the outer surface of the shroud 2 so as to form the bind blade of a gas turbine stationary blade. As a result, rigidity of the shrouds 2, 2 are reduced, a temperature distribution is released so as to reduce heat stress of a blade root part. Both parts are connected to each other utilizing a difference between heat expansion coefficients of the pin hole 11 of the shroud 2 and the pin 6 fitted to the pin hole 11, they are connected to each other through the installing plates 5, 5 by the fastening member 7, and relative movement between adjacent shrouds 2, 2 is prevented so as to provide a firm bind blade structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine stationary blade having a spelling blade structure.

[0002]

2. Description of the Related Art An outline of a conventional gas turbine stationary blade of this type will be described with reference to FIG.

FIG. 4 is a schematic view showing an example of a spelling blade structure in a conventional gas turbine stationary blade.
The inner shroud 1 and the outer shroud 2, which are arranged integrally on the inner side and outer side with respect to the gas turbine shaft, are connected on the inner side corresponding to the blade tip side and the outer side corresponding to the hub side to constitute a spelling blade.

[0004]

As described above, in the spelling blade structure for two blades in the conventional gas turbine stationary blade, the area occupied by the inner and outer shrouds 1 and 2 is equal to that of the blades 3 and 4. Because it covers a single blade, it naturally becomes wider than a single wing, and the thermal stress becomes severe.

In particular, the inner and outer shrouds 1 and 2 are
The connection portion that is connected to the inner and outer shrouds 1 and 2 is susceptible to the thermal deformation of the inner and outer shrouds 1 and 2, and is liable to be damaged by thermal stress.

An object of the present invention is to provide a wing structure which solves the above-mentioned disadvantages of the prior art and reduces the thermal stress of the wing due to the thermal deformation of the shroud. It is.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a pin hole extending in the incision direction on a dividing surface extending in the axial direction of the shroud, and the pin hole has a thermal expansion from the shroud. The present invention provides a gas turbine vane having a spelling blade formed by fitting a pin having a large coefficient to connect adjacent shrouds to each other and connecting a mounting plate provided along the dividing surface on the outer surface of the shroud with a fastening member. is there.

In other words, the thermal stress at the root of the blade is greatly affected by the thermal deformation of the shroud, which is governed by the rigidity and temperature distribution of the members, in addition to the thermal stress of the blade itself. Thereby, the rigidity of the shroud is reduced and the temperature distribution is also loosened, so that the thermal stress at the root of the blade is reduced.

The divided and adjacent shrouds are connected to each other by fitting a pin having a larger coefficient of thermal expansion than the shroud into a pin hole provided in the divided surface, and have a mounting plate provided along the divided surface by a fastening member. As a result, the relative movement between the adjacent shrouds is prevented, and the shrouds are integrally moved, so that a robust spell wing structure can be obtained.

[0010]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG. 1 shows an assembly of a gas turbine vane according to the present embodiment, FIG. 2 shows one of the divided parts of the assembly of FIG. 1, and FIG. 3 shows a support pin and a support pin which correspond to a basic part of the assembly of FIG. The details of the mounting plate and the like are shown.

The same parts as those of the prior art described above are denoted by the same reference numerals in FIGS. 1 to 3 so as to clarify their mutual relations and to facilitate understanding of the present embodiment. I made it.

In the present embodiment, the inner shroud 1 and the outer shroud 2 are each divided into two by a dividing surface 9 extending substantially in the axial direction of the turbine. It is separate from the one that joins the matching wings 4.

A pin hole 11 is formed in the dividing surface 9 so as to extend in the direction of the cutting line of the turbine rotation circle near both ends thereof and communicate with each other. Adjacent shrouds are connected to each other by a support pin 6 fitted in 11.

The support pin 6 has a coefficient of thermal expansion of 16
Hastelloy material equivalent to ~ 20 × 10 ^-6 / ° C.
The inner shroud 1 and the outer shroud 2 are made of a Ni-base heat-resistant alloy having a coefficient of thermal expansion of 12 to 16 × 10 ⁻⁶ / ° C., respectively.

The inner shroud 1 and the outer shroud 2 are each provided with a pin hole 11
And on the side closer to the flow side of the working gas than the support pin 6, that is, radially outward from the pin hole 11 and the support pin 6 in the inner shroud 1 and radially inward from the outer shroud 2, and straddling the dividing surface 9 of the adjacent shroud. Seal groove 12
The seal plate 8 is disposed in the seal groove 12 to ensure the sealing performance on the divided surface 9.

Further, the inner shroud 1 and the outer shroud 2
In the vicinity of the center of each divided surface 9, the pin hole 11 is formed in the inner shroud 1, contrary to the seal groove 12.
The mounting plate 5 is fixed to the inner side of the support pin 6 in the radial direction and to the outer side of the outer shroud 2 in the radial direction by welding 10, and the mounting plates 5 of the adjacent shrouds are brought together to be bolted as a fastening member. Are connected by

That is, in the present embodiment, the inner shroud 1 of the blade 3 and the inner shroud 1 of the blade 4, the outer shroud 2 of the blade 3, and the outer shroud 2 of the blade 4 are separately formed,
Inner shroud 1 and outer shroud 2 of wings 3 and 4
Combinations are made by fitting the pin holes 11 and the support pins 6 on the respective dividing surfaces 9 and by connecting the mounting plate 5 welded to the inside and outside of the dividing surface 9 with the bolts 7 to form the wings 3 and 4. It constitutes a spell wing.

The thermal stress at the root of the wing where the wings 3 and 4 are attached to the inner and outer shrouds 1 and 2, respectively, is
In addition to the thermal stress of itself, the influence of thermal deformation of the inner and outer shrouds 1 and 2 is large, and the effect of the outer shrouds 1 and 2 affects the rigidity and temperature distribution of the inner and outer shrouds 1 and 2. It is governed.

However, in the present embodiment, since the inner and outer shrouds 1 and 2 are divided as described above, the rigidity of the shroud is reduced, the temperature distribution is loosened, and deformation such as turning up is small. Therefore, the force acting on the wing is also reduced, and the thermal stress is reduced.

A support pin 6 having a larger coefficient of thermal expansion than the shroud has a pin hole between the division surface 9 corresponding to the blade 3 and the division surface 9 corresponding to the blade 4 while maintaining the seal by the seal plate 8. 11, the difference between the thermal expansion of the material forming the support pin 6 and the thermal expansion of the material forming the shroud which is the base of the pin hole 11 causes a difference between the support pin 6 and the pin hole 11. Is subjected to a surface pressure to prevent the influence of the relative displacement of the shroud at the position of the support pin 6 and to behave integrally, whereby the bolt 7 for fastening the mounting plate 5
Is greatly reduced, and the soundness of the spell wing structure is greatly improved.

Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to such embodiments.
It goes without saying that various changes may be made to the specific structure within the scope of the present invention.

[0022]

As described above, according to the present invention, a pin hole extending in the incision direction is provided on the dividing surface extending in the axial direction of the shroud, and a pin having a larger coefficient of thermal expansion than the shroud is fitted in the pin hole. While connecting the shrouds to each other, the shroud of the spell blade is divided by dividing the shroud of the gas turbine vane by connecting the mounting plate provided along the dividing surface on the outer surface of the shroud with a fastening member. With this configuration, the rigidity is lowered and the temperature distribution is also moderated, the thermal stress at the root of the blade is reduced, and the divided and adjacent shroud has a thermal expansion coefficient higher than that of the shroud in the pin hole provided on the dividing surface. Pins are fitted to each other using the difference in the coefficient of thermal expansion, and the pins are connected by a fastening member via a mounting plate provided along the dividing surface. The relative movement between the shroud mutual contact becomes integral behavior is prevented, in which it was possible to obtain a robust spelling wing structure.

[Brief description of the drawings]

FIG. 1 is an assembly view of a gas turbine vane according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a part of the assembly shown in FIG.

FIG. 3 is an explanatory diagram showing details of a support pin, a mounting plate, and the like corresponding to a basic portion of the assembly of FIG. 1;

FIG. 4 is a schematic diagram showing an example of a spelling blade structure in a conventional gas turbine stationary blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner shroud 2 Outer shroud 3 Blade 4 Blade 5 Mounting plate 6 Support pin 7 Bolt 8 Seal plate 9 Dividing surface 10 Welding 11 Pin hole 12 Seal groove

Claims (1)

[Claims] 1. A pin hole extending in a cutting line direction is provided on a dividing surface extending in an axial direction of a shroud, a pin having a larger thermal expansion coefficient than that of the shroud is fitted into the pin hole, and adjacent shrouds are connected to each other. A gas turbine stationary blade, wherein a spelling blade is formed by connecting mounting plates provided along the division surface with a fastening member.