JPH06129204A - Gas turbine cooling structure for gas turbine stator vane - Google Patents

Abstract

PURPOSE:To aim at uniforming the temperature of a small-size gas turbine blade in its entirety by uniformly distributing the stream. of cooling gas the inside of the blade. CONSTITUTION:A plurality of partitions 15 which are projected from the outer peripheral part of an insert 13 adapted to be inserted in a film cooling passage formed in the center part of the body of a gas turbine blade, and which abut at their front ends against the inner wall of the film cooling passage are arranged at the outer peripheral part of in a plurality of vertical rows. Further, partitions 16 which are projected from the leading end part of the insert 13 and which abut at their front ends against the inner peripheral wall of the film cooling passage are formed in a single row which extends heightwise of an insert. Holes 17 for controlling the flow rate of cooling gas 14 for every one of the spaces between the partitions 15 are formed. Further, bellows (seal) 18 having protrusions having a shape the same as that of, for example, the partitions 15 are formed in the cooling gas inlet end side part of the insert 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a gas turbine stationary blade, and more particularly to a hollow insert for insertion into a film cooling passage formed in a central portion of a main body of a small gas turbine stationary blade. Regarding improvement.

[0002]

2. Description of the Related Art In recent years, the temperature of combustion gas has been increased to improve the efficiency of gas turbines. Therefore, cooling of gas turbine stationary blades is very important for extending the life of the turbines. In the case of a stationary blade of a large gas turbine, the blade shape is large and a relatively large amount of cooling gas is used. Therefore, a complicated cooling passage may be provided in the blade body, or
As shown in FIG. 3, a hollow insert 03 having a large number of impingement cooling holes 02 is inserted into a cooling passage 01 formed in the central portion of the blade body. Note that 04
Is a seal plate for preventing cooling gas leakage, and 05 is a reinforcing plate for positioning.

On the other hand, in a small gas turbine stationary blade having a blade length of less than 100 mm, the cooling structure inside the blade must be simplified because the blade shape is small. That is, conventionally, as shown in FIG. 9, a film cooling passage 2 formed in the central portion of the main body of the gas turbine stationary blade 1 is used.
A simple cooling structure in which a hollow insert 3 is inserted in the cooling gas 4 and the cooling gas 4 is flown as shown by an arrow and is discharged from a discharge hole 5 in the lower portion of the blade to cool the gas turbine stationary blade 1 by film cooling is provided. I am collecting.

[0004]

As described above, the blade length is 1
In the case of a small-sized gas turbine vane of less than 00 mm, the cooling structure inside the blade must be simple as shown in FIG. 9, and in addition, cooling is required from the requirement of gas turbine performance. Since the amount of gas used is planned to be minimized, cooling is insufficient in the conventional example shown in FIG. 9, and the blade front and rear edges of the gas turbine stationary blade 1 become hot, causing a temperature imbalance throughout the blade. There was a problem that a temperature difference of several hundreds of degrees Celsius was generated.

In the cooling structure for a large gas turbine vane shown in FIG. 10, since the shape of the insert 03 and the shape of the impingement cooling hole 02 are made into a required shape, the temperature difference of the entire blade is increased. Can be designed small.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and particularly in a simple cooling structure applied to a small-sized gas turbine stationary blade, that is, in the central portion of the main body of the gas turbine stationary blade. In the cooling structure formed by inserting a hollow insert into the formed film cooling passage,
The purpose of the present invention is to distribute the cooling gas in the blade as evenly as possible to prevent the front and rear edges of the blade from becoming hot, and thereby to make the temperature of the entire blade uniform.

[0007]

In order to solve the above problems, the present invention relates to a gas turbine vane in which a hollow insert is inserted into a film cooling passage formed in a central portion of a blade body. In the cooling structure, the outer peripheral portion of the insert is formed with a plurality of partitions in the insert height direction, the partitions protruding from the outer peripheral portion and the tips abutting against the inner wall of the film cooling passage are formed in the front edge portion of the insert. The partition is formed in one row so as to extend in the insert height direction, the partition protruding from the front edge portion and having the tip abutting against the inner wall of the film cooling passage.

[0008]

According to the above means, since the insert is provided with the partition for distributing the cooling gas, the cooling gas can be evenly distributed and flowed inside the blade. The partition also acts as a reinforcement for the insert.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an example of an insert used in a cooling structure of a gas turbine stationary blade according to the present invention together with a flow of cooling gas, and FIG. 2 is a film in which the insert of FIG. 1 is formed in a central portion of a main body of the gas turbine stationary blade. FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 when inserted in the cooling passage, and FIG. 3 is a cross-sectional view taken along the line BB of FIG.

In these drawings, the gas turbine vane 1
A film cooling passage 12 is formed in the central portion of the main body 1 of FIG. 1, and a hollow insert 13 is inserted into the film cooling passage 12. Further, according to the present embodiment, the partition 15 is formed on the outer peripheral portion of the insert 13 in four rows in the insert height direction (blade height direction), the partition 15 protruding from the outer peripheral portion and having the tip abutting against the inner wall of the film cooling passage 12. The cooling gas 14 is evenly distributed in the blade height direction. In addition, also in the front edge portion of the insert 13 (blade front edge portion), a partition 16 protruding from the front edge portion and having a tip abutting the inner wall of the film cooling passage 12 extends in the insert height direction in one row. The cooling gas 14 is formed so that the cooling gas 14 is uniformly distributed to the blade back side and the blade antinode.

In this case, generally, in the gas turbine stationary blade 11, since the cooling gas 14 is less likely to flow even though the back side of the blade is hotter than the ventral side of the blade, the partition 16 is provided. Is preferably provided on the front edge of the insert 13 at a position closer to the blade back side.

By thus providing the partitions 13 and 16 for distributing the cooling gas in the insert 13, the cooling gas 1
4 are evenly distributed and flowed inside the blade, and the gas turbine stationary blade 1
It was possible to prevent the temperature of the front and rear edges from increasing, and to make the temperature of the entire blade uniform. According to the prototype blade, the maximum temperature difference was about 50 ° C.

The partitions 15 and 16 also function as a reinforcing material for the insert 13. That is, in the small gas turbine stationary blade 11, since the large film cooling passage 12 cannot be formed, the insert 13 can be thinned to about 0.1 mm to secure the film cooling passage 12. is necessary. Therefore, the partition plates 15 and 16 protruding from the insert 13 and contacting the inner wall of the film cooling passage 12 as described above prevent the thin insert 13 from being deformed by the cooling gas pressure and also serve as a reinforcing material. It is a thing.

Also, according to the preferred embodiment shown here,
At the front edge of the insert 13, an appropriate number of holes 17 are formed in the insert height direction at each part between the partitions 15, whereby the cooling gas 14 at each part between the partitions 15 is formed.
The temperature of the portion between the partitions 15 can be controlled by changing the flow rate of the partition 15.

That is, in the gas turbine stationary blade,
When the load fluctuation of the gas turbine is large, the temperature becomes higher on the outer peripheral side of the vane, and since the outer peripheral side of the vane has a larger thermal capacity, the stress strain becomes larger. Is what you need to do. In addition, the stationary blade is generally integrated with the outer peripheral ring (shroud ring), and by cooling the outer peripheral side strongly, the clearance between the moving blade and the outer peripheral ring can be controlled to be small, and the effect is to improve the efficiency of the gas turbine. It is possible.

Therefore, from the above description, it is necessary for the stationary blade to change the degree of cooling in the blade height direction. Therefore, in the preferred embodiment shown here, a plurality of cooling gas flow rate control holes 17 are formed in the front edge of the insert 13 in the insert height direction, and the holes 17 formed between the partitions 15 are formed. The flow rate of the cooling gas 14 is changed for each part between the partitions 15 by changing the number or size of the partitions 15, and a planned flow rate of the cooling gas is flowed for each part between the partitions 15. The size of the hole 17 is 0.5 to 1.5φ in order to obtain the impingement cooling effect.

Furthermore, according to the preferred embodiment shown here,
On the cooling gas inlet end side of the insert 13, for example, a bellows 18 having a projection shape similar to that of the partition 15 is formed, whereby the leakage of the cooling gas 14 is minimized.

Next, FIGS. 4, 5 and 6 show a partition 15 formed on the outer periphery of the insert 13 according to the present invention.
3 shows three different protrusion shapes. That is, in FIG. 4, the tip of the protrusion of the partition 15 is formed into a flat shape so that the leakage of the cooling gas is minimized. Also, FIG. 5 and FIG.
The partition plate 15 has a conical shape and a pyramidal shape, and the tip portion thereof is crushed by contact with the inner wall of the film cooling passage 12 to enhance the sealing effect. In this case, as shown in FIGS. 7 and 8, the sealing effect can be further improved by forming a groove 19 having the same shape as the projection tip shape of the partition 15 on the inner wall side of the film cooling passage 12. it can.

[0019]

As described above, according to the present invention, in the cooling structure for the gas turbine stationary blade, the hollow insert is inserted into the film cooling passage formed in the central portion of the blade body. A plurality of partitions are formed on the outer peripheral portion of the insert so that the tip of the insert abuts the inner wall of the film cooling passage in multiple rows in the insert height direction, and the front edge portion of the insert also protrudes from the front edge portion. By forming the partition whose front end abuts the inner wall of the film cooling passage in one row so as to extend in the insert height direction, the cooling gas can be evenly distributed and flowed inside the blade by the partition. The temperature of the front and rear edges of the gas turbine vane can be prevented and the temperature of the entire blade can be made uniform, and each partition also functions as a reinforcement material for the insert. Optimal cooling structure is applied to a small gas turbine stationary blade is provided Te.

Further, according to the above-mentioned embodiment, by forming an appropriate number of cooling gas flow rate control holes in the insert height direction at the front edge portion of the insert at each part between the partitions, the space between the partitions is formed. The flow rate of the cooling gas can be changed for each part to control the temperature of the part between the partitions.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an insert used in a cooling structure for a gas turbine stationary blade according to the present invention.

FIG. 2 shows a state in which the insert of FIG. 1 is inserted into a film cooling passage formed in a central portion of a main body of a gas turbine stationary blade,
It is sectional drawing shown along the AA line of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a cross-sectional view showing an example of a protrusion shape of a partition formed on the outer peripheral portion of the insert according to the present invention.

FIG. 5 is a cross-sectional view showing another example of the projection shape of the partition.

FIG. 6 is a cross-sectional view showing still another example of the projection shape of the partition.

7 is a cross-sectional view showing a modified example of FIG.

8 is a cross-sectional view showing a modified example of FIG.

FIG. 9 is a perspective view showing a conventional cooling structure applied to a small gas turbine stationary blade.

FIG. 10 is a perspective view showing an insert in a conventional cooling structure applied to a large-sized gas turbine stationary blade.

[Explanation of symbols]

 11 Gas Turbine Blades 12 Film Cooling Passage 13 Insert 14 Cooling Gas 15 Partition 16 Partition 17 Cooling Gas Flow Control Hole 18 Bellows

Claims (1)

[Claims] 1. A cooling structure for a gas turbine stationary blade, wherein a hollow insert is inserted into a film cooling passage formed in a central portion of a blade body, and a tip is projected from the outer peripheral portion to the outer peripheral portion of the insert. Form a plurality of partitions in contact with the inner wall of the film cooling passage in the insert height direction, and the front edge of the insert also protrudes from this front edge so that the tip contacts the inner wall of the film cooling passage. 1 so that the contacting partition extends in the insert height direction
A cooling structure for a gas turbine vane, which is characterized in that rows are formed.