JPH04203202A - Gas turbine moving blade - Google Patents

Abstract

PURPOSE:To prevent breakage due to thermal stress of a sleeve by dividing the sleeve provided movable to a blade span direction between a blade tip part and a blade root part into a top end sleeve and an intermediate sleeve, and so forming respective parting faces that their sleeve lengths successively change to the direction of their thicknesses. CONSTITUTION:In the moving blade of a gas turbine, a sleeve 12 constituting a moving blade 4 is loosely fitted in an intermediate part 3 of the supporting member 2 of a blade main body 11 constituted having the supporting member 2, and it is made movable in a blade span direction between a blade tip part 6 and a blade root part 7 provided on the both ends of the intermediate part 3. A duct 8 is formed in an opening between the inner surface of the sleeve 12 and the intermediate part 3 of the supporting member 2. Here, the sleeve 12 is halved in a blade span direction, and constituted from a top end sleeve 13 that constitutes a blade top end side and an intermediate sleeve 14 that constitutes a part ranging from the intermediate part till a blade root side. Respective parting faces 15, 16 are formed over the entire circumference in an inclined face wherein its sleeve length from a sleeve inner surface side to an outer surface side changes in the direction of thickness, so that their facing surfaces become inverse shapes with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention particularly relates to a high-temperature gas turbine rotor blade in which the surface of the blade portion is made of a ceramic material.

(Prior Art) As is well known, in order to improve the utility efficiency of a gas turbine, it is effective to increase the artificial gas temperature of the turbine, that is, the temperature of the combustion gas introduced into the turbine.

In response to the rise in artificial gas temperature, efforts are being made to improve the heat resistance of the wing portions that are directly exposed to high temperatures.

Among these, there is a high-temperature gas turbine rotor blade that uses a highly heat-resistant ceramic material as a constituent material of the blade portion.

Hereinafter, a conventional gas turbine rotor blade using ceramic as a constituent material will be described with reference to the drawings.

FIG. 5 is a schematic diagram of a longitudinal section of a rotor blade of a gas turbine.
FIG. 6 is a characteristic diagram showing the temperature distribution of the sleeve. In the figure, ] is a wing body, which has a support member 2 and a sleeve 5 that is loosely fitted into the intermediate portion 3 of the support member 2 and forms a substantial wing portion 4 . A plurality of blade bodies] are fixed to the rotating shaft of a turbine (not shown) by the root part of the support member 2 to form a blade row, and during operation, the rotor rotates at high speed, thereby receiving a large centrifugal force in the blade span direction. .

The support member 2 is made of a heat-resistant metal such as a Ni-based alloy or a Co-based alloy, and a sleeve 5 is loosely fitted into the intermediate portion 3 of the support member 2 and forms a wing portion 4 exposed to high-temperature combustion gas. are made of a ceramic material such as silicon nitride (S 13N4) or silicon carbide (S i C), and are formed to have approximately the same thickness. Further, in the support member 2, a blade tip part 6 and a blade root part 7 having an airfoil-shaped cross section and a larger cross-sectional shape than the intermediate part 3 are formed on both end sides of the intermediate part 3 in the blade span direction. A sleeve 5 having a length of, for example, 40 to 50 mm is fitted between the end portion 6 and the blade root portion 7 so as to be movable, for example, by 1 mm in the blade span direction.

A cooling air flow path 8 is formed in the gap between the inner surface of the sleeve 5 and the intermediate portion 3 of the support member 2, and a cooling air flow path 8 is formed in the support member 2 for supplying cooling air. The introduced passage 9 is open. In addition, the flow passage 8 is a discharge passage formed between the end face on the blade tip side and the end face on the blade root side of the sleeve 5, and each side surface of the blade tip 6 and the blade root 7 of the support member 2 facing these.] 0, and the cooling air is discharged to the outside of the blade body from this discharge passage 10.

Note that cooling air is supplied to the introduction path 9 through a cooling air supply path provided on a rotating shaft installed in the blade body.

The conventional gas turbine rotor blade described above is operated while cooling the sleeve 5 by supplying cooling air to the flow path 8 through the introduction path 9. Note that the cooling air supplied to the flow passage 8 and used for cooling is discharged from the discharge passage 10. At this time, since the sleeve 5 is movable in the blade span direction, the discharge path 10 formed by the end surface of the sleeve 5 and the side surfaces of the blade tip 6 and the blade root 7 of the support member 2 is created by rotation of the sleeve 5. The cooling air is pressed against the wing tip side by centrifugal force, and the cooling air flows into the sleeve 5.
and the side surfaces of the blade tip 6 and blade root 7 of the support member 2. In other words, the cooling air is discharged through a small gap between the blade tips 6 of the sleeve 5 support part 2 by the pressure of the cooling air.

During operation, combustion gas acts directly on the blade section 4, and the temperature distribution in the span direction of the sleeve 5 is shown in FIG.
This is illustrated with the portion of the sleeve 5 plotted on the vertical axis.

In other words, the highest temperature of the sleeve 5 is biased toward the blade tip, and the temperature is lower at the end surface of the sleeve 5 on the blade tip side and the end surface on the blade root side, where cooling air is discharged from the jJP river channel 0. Shows temperature. For this reason, the sleeve 5 has a large temperature gradient from the end surface on the blade tip side to the portion exhibiting the highest temperature, and a small temperature gradient from the portion exhibiting the maximum temperature to the end surface portion on the blade root side.

In this way, since a large temperature gradient occurs in the sleeve 5 at the blade tip side, the tensile force from the end surface area to the area showing the highest temperature in the intermediate area on the blade tip side acts as thermal stress, causing a temperature gradient. It acts more strongly than the opposite thermal stress on the blade root side, where the curvature is small, and it acts particularly strongly on the leading and trailing edges where the curvature is small. For this reason, there is a risk that the sleeve 5 may be damaged during operation, and the sleeve 5 may
Due to the strength of gas turbines, it is not possible to provide a reliable and sufficient measure, and a situation may arise where restrictions must be placed on the operating conditions of the gas turbine.

(Problems to be Solved by the Invention) The present invention was made in view of the above-mentioned situation where the sleeve forming the wing section has a problem due to thermal stress, and its purpose is to prevent the sleeve from being damaged during operation. It is an object of the present invention to provide a gas turbine rotor blade that can cope with high temperature inlet gas temperature and high output with sufficiently high reliability from the viewpoint of strength.

[Configuration of the Invention (Means for Solving the Problems) The gas turbine rotor blade of the present invention includes a blade body including a sleeve formed of a ceramic material and a support member in which the sleeve is loosely fitted in the intermediate portion. A sleeve is provided between the wing tip and the wing root formed at both ends of the intermediate section so as to be movable in the wing span direction, and the sleeve is divided into at least a tip sleeve and an intermediate sleeve. The dividing surfaces of these tip sleeves and intermediate sleeves are shaped so that the length of the sleeve changes continuously in the thickness direction, and each dividing surface is a surface that faces each other. is characterized in that it has an inverted shape.

(Function) The cast turbine rotor blade configured as described above is divided into at least a tip sleeve and an intermediate sleeve by dividing the sleeve of ceramic material forming the blade portion into parts where the temperature gradient becomes large. However, since the divided surfaces of these sleeves are configured to face each other or have opposite shapes, and the length of the sleeve changes continuously in the thickness direction, there is no difference between the tip sleeve and the sleeve at the divided portion. The intermediate sleeves can freely expand and contract without being restrained by each other, and there is no possibility that the sleeves will be misaligned due to division. There is no risk that the sleeve will be damaged during operation, and in terms of strength, it is possible to respond to high temperature inlet gas temperatures and high output of the gas turbine with sufficiently high reliability.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. still,
Components that are the same as those in the prior art are denoted by the same reference numerals and explanations are omitted, and the configuration of the present invention that is different from the prior art will be described.

First, a first embodiment will be explained with reference to FIGS. 1 and 2.

Figure 1 is a schematic diagram of a vertical cross section of a rotor blade of a gas turbine.
FIG. 2 is a perspective view of the sleeve. In the figure, reference numeral 11 denotes a wing body having a support member 2 as in the conventional example. At the intermediate portion 3 of the support member 2 of the wing body 11, a sleeve 1 having a length of 40+nm, for example, which constitutes the wing portion 4 is provided.
2 are loosely fitted, and are provided so as to be movable within a range of 1 mm in the blade span direction between a blade tip 6 and a blade root 7 provided at both ends of the intermediate portion 3. Note that a flow path 8 is formed in the gap between the inner surface of the sleeve 12 and the intermediate portion 3 of the support member 2, and a flow path 8 is formed in the gap between the inner surface of the sleeve 12 and the intermediate portion 3 of the support member 2. wing tip 6
A discharge passage 10 is formed between the blade root portion 7 and each side surface of the blade root portion 7.

Furthermore, the sleeve 12 is divided into two parts in the blade span direction, with a tip sleeve 13 forming the blade tip side and an intermediate sleeve forming the part from the middle part to the blade root side of the same blade shape as this tip sleeve 13.] It consists of 4. The division position between the tip sleeve 13 and the intermediate sleeve 14 is the sixth
In the characteristic curve of the temperature distribution during operation illustrated in the figure, the amount of deformation of each sleeve 13, 14 is in the intermediate part between the end face part on the blade tip side where the temperature gradient is large and the part showing the highest temperature in the middle part. It should be placed in a position where the strength is within the allowable range. The dividing surface 15 of the tip sleeve 13 has an inclined surface shape over the entire circumference so that the length of the sleeve from the inner surface to the outer surface of the sleeve in the thickness direction, that is, the length in the span direction, decreases linearly. ing. On the other hand, the dividing surface 16 of the intermediate sleeve 14 is inclined so that the length of the sleeve from the inner surface to the outer surface increases linearly in the thickness direction, contrary to the tip sleeve 13. It has a curved surface shape. Note that the sloped surface shapes of the dividing surface 15 of the distal sleeve 13 and the dividing surface 16 of the intermediate sleeve 14 are the respective dividing surfaces], 5. ], 6 are formed in opposite shapes to each other so that when the distal end sleeve 13 and the intermediate sleeve 14 constitute an integral sleeve 12, the opposing surfaces coincide with each other.

In this embodiment, which has a secondary configuration, during operation of the gas turbine, cooling air is supplied to the flow passage 8 through the introduction passage 9 to cool the sleeve 12, that is, the tip sleeve 13 and the intermediate sleeve 4. being driven while

At this time, the sleeve 12 is pressed against the blade tip side by centrifugal force as in the conventional example, and cooling air is discharged from the gap between the sleeve j2 and the support member 2.

In addition, the sleeve 12 includes a tip sleeve 13 and an intermediate sleeve 1.
Since it is divided into 4 and loosely fitted to the support member 2,
Is it possible that a positional shift occurs between both sleeves 13□14?The shape of each dividing surface 1.5.113 is an inclined surface that changes linearly in the thickness direction of the sleeve over the entire circumference. , both sleeves 1.3. are pressed against the dividing surface 15 by centrifugal force. ]4 Mutual positional deviation will not occur.

Therefore, the sleeve 12 can maintain a predetermined wing shape during operation.

Since the sleeve 12 is divided into the distal end sleeve 13 and the intermediate sleeve J4, each dividing surface is 15° and 16°.
Slippage can occur at Therefore, each divided sleeve 13.14 can be deformed depending on the temperature gradient in the blade span direction, and can freely expand and contract without being constrained by each sleeve 13.1.4. Therefore, each sleeve 13.1.4
The thermal stress does not act too strongly.

As mentioned above, the tip sleeve 13 and the intermediate sleeve 14 have different temperatures during operation, so the thermal expansion conditions are also different, and the intermediate sleeve 14, which has a higher temperature, deforms in the direction of increasing the cross-sectional shape of the airfoil. , and also deforms to elongate in the wing span direction. As a result, if the blade shapes of the tip sleeve 13 and the intermediate sleeve 14 are the same when the operation is stopped,
During operation, the contact position between the dividing surface 15 and the dividing surface 6 is shifted in the thickness direction, so that the dividing surface 15 is in contact with the inner corner of the intermediate sleeve 14 at the dividing surface 16, or the dividing surface 15 is in contact with the dividing surface 15.
It is conceivable that the outer corner of the tip sleeve 13 presses the dividing surface 16 with centrifugal force and a large stress concentration occurs, but the angle formed by the dividing surface 16 and the inner surface of the intermediate sleeve 14 is an obtuse angle. Moreover, the angle formed by the dividing surface 15 and the outer surface of the tip sleeve 13 is an obtuse angle, and stress concentration at these corners is not large. Note that the expansion of the intermediate sleeve 14 in the blade span direction, which becomes hot, is not restricted because it is provided movably in the blade span direction.

In this way, according to this embodiment, even if the sleeve 12 forming the wing section 4 is divided, both the divided sleeves 1
．． A desired blade shape can be obtained without positional deviation between 3 and 14, there is no risk of large stress concentration due to thermal expansion or centrifugal force, and no damage will occur due to stress concentration. Further, a large temperature gradient does not occur in the blade tip side portion of the sleeve 12, and thermal stress does not act to a large extent even in the leading edge and trailing edge having a small curvature.

For this reason, there is no risk that sleeve 2 will be damaged during operation, and sleeve
2, the reliability is high in terms of strength, and there is no need to impose restrictions on the operating conditions of the gas turbine.

Next, a second embodiment will be explained with reference to FIG.

FIG. 3 is a partial vertical sectional view of the sleeve, and in the figure,
] 8 is a sleeve made of a ceramic material that forms the wing part as in the first embodiment, and is divided into two in the wing span direction, including a tip sleeve 19 that makes up the tip side of the wing, and a sleeve that is the same as this tip sleeve 19. It is composed of an intermediate sleeve 20 that constitutes a portion from the middle part of the blade shape to the blade root side. The dividing position of the tip sleeve 19 and the intermediate sleeve 20 is set at the intermediate portion between the end surface portion on the blade tip side where the temperature gradient is large and the portion exhibiting the highest temperature in the intermediate portion, as in the first embodiment. The dividing surface 21 of the tip sleeve 19 is a curved surface that is inclined so that the length of the sleeve increases continuously in a curved manner from the inner surface to the outer surface in the thickness direction over the entire circumference, and the ends are the inner and outer surfaces. 1B - The shape is such that the angles formed are approximately right angles. On the other hand, the dividing surface 22 of the intermediate sleeve 20 is a curved surface that is inclined so that the length of the sleeve from the inner surface to the outer surface in the thickness direction continuously decreases in a curved manner, contrary to the tip sleeve 19. The end portion is shaped so that the angle formed by the inner and outer surfaces is approximately a right angle. Note that the dividing surface 21 of the tip sleeve 19 and the dividing surface 2 of the intermediate sleeve 20
The shapes of the two surfaces are opposite to each other so that when the distal end sleeve 19 and the intermediate sleeve 20 constitute an integral sleeve 18 by combining the dividing surfaces 21 and 22, the opposing surfaces coincide with each other.

This embodiment with the above configuration also provides the same functions and effects as the first embodiment.

Furthermore, a third embodiment will be explained with reference to FIG.

FIG. 4 is a partial vertical sectional view of the sleeve, and in the figure,
25 is made of a ceramic material that forms the wing section as in the first embodiment, and is divided into two parts in the span direction with a dividing position located midway between the end surface section on the wing tip side and the area exhibiting the highest temperature. It's a sleeve. This sleeve 25 is composed of a tip sleeve 26 that makes up the blade tip side and an intermediate sleeve 27 that makes up the part from the middle part to the blade root side.The intermediate sleeve 27 is designed to have the same blade shape as the tip sleeve 26 during operation. It is formed into a small wing shape that allows for thermal expansion.

The dividing surface 28 of the tip sleeve 26 extends over the entire circumference.
The surface is inclined so that the length of the sleeve increases linearly from the inner surface to the outer surface in the thickness direction. On the other hand, the dividing surface 29 of the intermediate sleeve 27 is an inclined surface extending over the entire circumference such that the length of the sleeve from the inner surface to the outer surface in the thickness direction decreases linearly, contrary to the tip sleeve 26. It has a shape.

Note that the dividing surface 28 of the tip sleeve 26 and the intermediate sleeve 2
The surface shape of the dividing surface 29 of No. 7 is the same as that of each dividing surface 28.2.
9 are formed in opposite shapes to each other so that when they are aligned, the opposing surfaces coincide with each other.

In this embodiment with the above configuration, during operation, the tip sleeve 26
The intermediate sleeve 27, which has a higher temperature, becomes larger in the shape of a wing and has the same shape as the tip sleeve 26. Therefore, stress concentration due to centrifugal force does not occur at both dividing surfaces 28 and 29. Further, at the time of starting up the operation, the contact position between the dividing surface 28 and the dividing surface 29 is shifted in the thickness direction, and the outer corner of the intermediate sleeve 27 at the dividing surface 29 touches the dividing surface 28. Further, the inner corner of the tip sleeve 26 at the dividing surface 28 presses the dividing surface 29 by centrifugal force, but since the rotation speed is low and the angle formed by the corner is obtuse, no large stress concentration occurs.

Also in this embodiment, the same functions and effects as in the first embodiment can be obtained.

Note that the present invention is not limited to the above embodiments. In other words, the number of divisions of the sleeve may be three or more, there is no need to provide an inclined division surface all around the circumference, there is no need for the division surface to have the same shape all around the circumference, and the division surface The size of the angle formed by the inner and outer surfaces is preferably an obtuse angle, but it may be set within the strength-permissible range along with the direction of inclination. It's something you get.

[Effects of the Invention] As is clear from the above description, the present invention divides the sleeve into at least a distal end sleeve and an intermediate sleeve, and changes the dividing plane of each of these sleeves continuously in the sleeve length or thickness direction. By constructing them in this manner and configuring the surfaces facing each other to have opposite shapes, the following effects can be obtained. In other words, even if the sleeve is made of ceramic material, there is no risk of damage to the sleeve during operation, it is possible to rotate at higher speeds, the rotor can be made larger, and it is also possible to increase the temperature of the gas at the inlet of the gas turbine. It can handle increased output with sufficiently high reliability in terms of strength.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view showing a first embodiment of the present invention;
2 is a perspective view of the sleeve in FIG. 1, FIG. 3 is a partial vertical sectional view of the sleeve of the second embodiment, FIG. 4 is a partial vertical sectional view of the sleeve of the third embodiment, and FIG. 5 6 is a schematic longitudinal cross-sectional view showing a conventional example, and FIG. 6 is a characteristic diagram showing the temperature distribution of the sleeve. 2... Supporting member, 3. Intermediate portion, 6. Wing tip portion,
7... Wing root, 11... Wing body, 12...
・Sleeve, 13...Tip sleeve, 14...
Intermediate sleeve, 1, . 5, i, 6... Division plane. Agent Patent Attorney Norihiro Ogo −<l ■ × Yen ω ■ Bit Ij−)C
D size

Claims (1)

[Claims] The blade body includes a sleeve made of a ceramic material and a support member in which the sleeve is loosely fitted in the middle part,
The sleeve is provided between a wing tip portion and a wing root portion formed at both ends of the intermediate portion so as to be movable in the wing span direction, wherein the sleeve is divided into at least a tip sleeve and an intermediate sleeve. The dividing surfaces of the tip sleeve and the intermediate sleeve are shaped so that the length of the sleeve changes continuously in the thickness direction, and each dividing surface is a surface that faces each other. A gas turbine rotor blade characterized in that the blades have an inverted shape.