JP2012177377A - Gas turbine blade and gas turbine equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine blade capable of improving the heat transfer performance of a serpentine flow path.SOLUTION: The serpentine flow path is formed of second-fourth cooling flow paths 12B, 12C, 12D so that the second cooling flow path 12B is situated at the most downstream side. A first wall 22A and a third wall 22C are disposed so that a space therebetween is gradually wider from the belly side toward the back side of the blade. A second wall 24B extends approximately parallel to the first wall 22A. A second flow path 12B having an approximately square cross section is formed of the first wall 22A, a back sidewall 4B of the blade, the second wall 24B and a belly sidewall 4A of the blade. A third flow path 12C having an approximately triangular cross section is formed of the second wall 24B, the belly sidewall 4A of the blade and the third wall 22C.

Description

  The present invention relates to a gas turbine blade having a cooling structure.

  In recent years, in order to improve gas turbine performance, the inlet temperature of the combustion gas flowing into the gas turbine blade has been increasing, and will reach 1700 ° C in the future. For this reason, various cooling structures for gas turbine blades have been developed. As one of the cooling structures, a serpentine channel is known in which a plurality of cooling channels are formed in the blade along the span direction, and these are folded and connected at the base or tip of the blade ( Patent Document 1).

JP-A-8-144704 (see FIG. 1)

  The cooling fluid flowing in the serpentine flow path has a problem that the temperature rises due to the heat received by cooling the gas turbine blade, and the desired cooling performance cannot be exhibited on the downstream side. On the other hand, measures have been taken to increase the heat transfer performance by providing a turbulator in the flow path, but this is not sufficient in view of the future temperature rise of the combustion gas.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the gas turbine blade which can improve the heat-transfer performance of a serpentine flow path, and a gas turbine provided with the same.

In order to solve the above problems, the gas turbine blade of the present invention and the gas turbine provided with the same employ the following means.
That is, in the gas turbine blade according to the present invention, a plurality of cooling passages extending from the base end side to the tip end side of the blade are provided from the leading edge to the trailing edge of the blade, and at least two of these cooling passages are In the gas turbine blade having a serpentine flow path that is folded back and connected at the base end portion or the distal end portion, the serpentine flow path is a cooling flow path on the most downstream side from a cooling flow path on the most upstream side of the serpentine flow path. The channel cross-sectional area is formed so as to become smaller in order.

  Since the flow path cross-sectional area of the cooling flow path constituting the serpentine flow path is formed so as to decrease sequentially from the most upstream side to the most downstream side, the flow velocity increases as the cooling fluid flows downstream. Therefore, even if the temperature of the cooling fluid rises as it flows downstream, a decrease in heat transfer performance can be compensated for by an increase in flow velocity.

  Furthermore, in the gas turbine blade according to the reference example of the present invention, the first wall portion that divides the first cooling flow path located on the front edge side and the second cooling flow path adjacent to the rear edge side of the first cooling flow path. A second wall section that divides the second cooling flow path and a third cooling flow path adjacent to the rear edge side of the second cooling flow path, and the third cooling flow path and the third cooling flow path A third wall section defining a fourth cooling channel adjacent to the rear edge side, and the serpentine is provided by the second to fourth cooling channels so that the second cooling channel is located on the most downstream side. A flow path is formed, and the first wall portion and the third wall portion are disposed such that a distance therebetween is spaced from the ventral side of the wing toward the back side, and the second wall portion is The second flow extending substantially parallel to the three wall portions and having a substantially triangular cross section by the first wall portion, the second wall portion and the back side wall portion of the wing. The third flow path having a substantially rectangular cross section is formed by the second wall portion, the back side wall portion of the wing, the third wall portion, and the abdominal side wall portion of the wing. To do.

  Since the first wall portion and the third wall portion are arranged so that these intervals are spaced from the flank side of the wing toward the back side, the first wall portion, the third wall portion, and the flank side wall of the wing. The cross-sectional shape formed by the wing portion and the back side wall portion of the wing is a substantially trapezoidal shape in which the abdominal side wall portion of the wing is a short side, the back side wall portion of the wing is a long side, and the first and third wall portions are hypotenuse It becomes. This trapezoid was divided into a triangular shape and a quadrangular shape by a second wall portion extending in parallel with the third wall portion. Thereby, the rectangular shape which does not become flat as much as possible can be obtained by using the belly side wall part of the wing | blade used as the short side of a trapezoid as one side of a square. Therefore, the heat transfer area of the abdominal side wall can be increased, and the cooling capacity of the blade is increased.

  Furthermore, in the gas turbine blade according to the reference example of the present invention, the second wall portion is connected to the first wall portion without being connected to the abdominal side wall portion of the blade.

  Since the second wall portion is connected to the first wall portion without being connected to the abdominal side wall portion of the wing, the abdominal side wall portion of the wing is not covered with the thickness of the second wall portion. Therefore, it is possible to secure a heat transfer area in which the abdominal side wall portion of the blade is in direct contact with the cooling fluid without being obstructed by the second wall portion, and the cooling capacity is increased.

  Further, in the gas turbine blade of the present invention, the first wall section that partitions the first cooling flow path located on the front edge side and the second cooling flow path adjacent to the rear edge side of the first cooling flow path, A second wall section that defines a second cooling flow path and a third cooling flow path adjacent to the rear edge side of the second cooling flow path; adjacent to the rear edge side of the third cooling flow path and the third cooling flow path The serpentine channel is formed by the second to fourth cooling channels so that the second cooling channel is located on the most downstream side. The first wall portion and the third wall portion are arranged so that the distance between them is separated from the ventral side of the wing toward the back side, and the second wall portion is separated from the first wall portion. The second flow extending substantially in parallel and having a substantially quadrangular cross section by the first wall portion, the back side wall portion of the wing, the second wall portion, and the abdominal side wall portion of the wing. There is formed, the second wall portion, the ventral side wall portion of the blade, wherein the third flow path is formed having a substantially triangular cross-section by the third wall portion.

  Since the first wall portion and the third wall portion are arranged so that these intervals are spaced from the flank side of the wing toward the back side, the first wall portion, the third wall portion, and the flank side wall of the wing. The cross-sectional shape formed by the wing portion and the back side wall portion of the wing is a substantially trapezoidal shape in which the abdominal side wall portion of the wing is a short side, the back side wall portion of the wing is a long side, and the first and third wall portions are hypotenuse It becomes. The trapezoid is divided into a quadrangular shape and a triangular shape by a second wall portion extending in parallel with the first wall portion. Thereby, the rectangular shape which does not become flat as much as possible can be obtained by using the belly side wall part of the wing | blade used as the short side of a trapezoid as one side of a square. Thereby, the heat-transfer area of an abdominal side wall part can be enlarged, and the cooling capacity of a wing | blade increases.

  Furthermore, in the gas turbine blade of the present invention, the second wall portion is connected to the third wall portion without being connected to the abdominal side wall portion of the blade.

  Since the second wall portion is connected to the third wall portion without being connected to the abdominal side wall portion of the wing, the abdominal side wall portion of the wing is not covered with the thickness of the second wall portion. Therefore, it is possible to secure a heat transfer area in which the abdominal side wall portion of the blade is in direct contact with the cooling fluid without being obstructed by the second wall portion, and the cooling capacity is increased.

A gas turbine according to the present invention includes any one of the above gas turbine blades.
Since the gas turbine blade described in any of the above is provided, a gas turbine having excellent cooling performance can be provided.

  Since the cross-sectional area of the cooling flow path constituting the serpentine flow path is gradually reduced from the most upstream side to the most downstream side, even if the temperature of the cooling fluid rises as it flows downstream, it is transmitted by the increase in flow rate. It can compensate for the decrease in heat. Thereby, high cooling efficiency can be obtained with a small amount of cooling air which is the minimum necessary.

It is a cross-sectional view of the gas turbine blade according to the first reference embodiment of the present invention. 1 is a cross-sectional view of a gas turbine blade according to a first embodiment of the present invention. It is a cross-sectional view of a gas turbine blade according to a second reference embodiment of the present invention. It is a longitudinal section of a gas turbine blade concerning one embodiment of the present invention.

Embodiments according to the present invention will be described below with reference to the drawings.
[First embodiment]
FIG. 4 shows a longitudinal section of the gas turbine blade according to the present embodiment.
The gas turbine blade 1 shown in the figure is suitable for use in a moving blade. The gas turbine blade 1 includes a base portion 6 that forms a platform, and a blade portion 4 that stands up (in the radial direction) above the base portion 6 and that forms a blade profile.

  The base 6 is provided with a first air introduction path 10A, a second air introduction path 10B, and a third air introduction path 10C through which cooling air that is a cooling fluid is introduced. As the cooling air, a part of the air compressed by the compressor that compresses the combustion air is used.

  A plurality of cooling passages extending in the span direction of the blade are formed in the blade portion 4, and the first cooling passage 12A, the second cooling passage 12B, A third cooling channel 12C, a fourth cooling channel 12D, a fifth cooling channel 12E, a sixth cooling channel 12F, a seventh cooling channel 12G, and an eighth cooling channel 12H are formed.

  The first cooling flow path 12A is connected to the first air introduction path 10A. The cooling air introduced from the first air introduction passage 10A flows in the first cooling passage 12A from the lower side to the upper side (outward in the radial direction), and flows out from a film cooling hole (not shown) to the outside. Cool the outer surface of the.

  The second to fourth cooling channels 12B, 12C, and 12D form a series of serpentine channels. That is, the fourth cooling flow path 12D is connected so that it is the most upstream, the third cooling flow path 12C is downstream, and the second cooling flow path 12B is most downstream. The fourth cooling flow path 12D and the third cooling flow path 12C are folded back and connected at the tip of the blade. Further, the third cooling flow path 12C and the second cooling flow path 12B are folded and connected at the base end portion of the blade. The second air introduction path 10B is connected to the fourth cooling flow path 12D, and the cooling air introduced from the second air introduction path 10B is the fourth cooling flow path 12D, the third cooling flow path 12C, It flows in the order of 2 cooling flow paths 12B. The cooling air that has flowed to the second cooling flow path 12B flows out from the film cooling hole (not shown) to cool the outer surface of the blade.

  The fifth to seventh cooling channels 12E, 12F, and 12G form a series of serpentine channels. That is, the fifth cooling channel 12E is connected to the most upstream, the sixth cooling channel 12F is connected to the downstream, and the seventh cooling channel 12G is connected to the most downstream. The fifth cooling flow path 12E and the sixth cooling flow path 12F are folded and connected at the tip of the blade. Further, the sixth cooling flow path 12F and the seventh cooling flow path 12G are folded and connected at the base end portion of the blade. The third air introduction path 10C is connected to the fifth cooling flow path 12E, and the cooling air introduced from the third air introduction path 10C is the fifth cooling flow path 12E, the sixth cooling flow path 12F, It flows in the order of 7 cooling flow paths 12G. The cooling air that has flowed into the seventh cooling flow path 12G flows out from the film cooling hole (not shown) to cool the outer surface of the blade.

  Cooling air is introduced into the eighth cooling passage 12H from an air introduction passage (not shown), and the introduced cooling air flows upward (radially outward) in the eighth cooling passage 12H and the trailing edge of the blade. Out to the outside.

FIG. 1 shows a cross section of the gas turbine blade 1. Of the symbols entered in each cooling channel 12 in the figure, a symbol with a solid point in the circle means that the cooling air flows radially outward (from below to above in FIG. 4) in the channel. A symbol with a cross in the circle means that the cooling air flows inward in the radial direction (from top to bottom in FIG. 4).
As shown in the figure, the first cooling channel 12A and the second cooling channel 12B are partitioned by the first wall portion 22A. Similarly, the second cooling channel 12B and the third cooling channel 12C are the second wall portion 22B, and the third cooling channel 12C and the fourth cooling channel 12D are the third wall portion 22C and the fourth cooling channel 12D. The fifth cooling channel 12E is the fourth wall 22D, the fifth cooling channel 12E and the sixth cooling channel 12F are the fifth wall 22E, and the sixth cooling channel 12F and the seventh cooling channel 12G are the sixth wall. The part 22F, the seventh cooling channel 12G, and the eighth cooling channel 12H are each partitioned by the seventh wall 22G.

  The serpentine flow path formed by the second to fourth cooling flow paths 12B, 12C, and 12D has a flow path cross-sectional area that is sequentially reduced in accordance with the flow direction of the cooling air. That is, the cross-sectional area of the third cooling flow path 12C downstream of the fourth cooling flow path 12D that is the most upstream is smaller than that of the third cooling flow path 12C. The cooling channel 12B has a smaller channel cross-sectional area.

  In addition, the serpentine flow paths formed by the fifth to seventh cooling flow paths 12E, 12F, and 12G also have flow path cross-sectional areas that are sequentially made smaller according to the flow direction of the cooling air. That is, the cross-sectional area of the sixth cooling flow path 12F downstream of the fifth cooling flow path 12E that is the most upstream is smaller than that of the sixth cooling flow path 12F. The cooling channel 12G has a smaller channel cross-sectional area.

As described above, by forming the flow passage cross-sectional area of the cooling flow passage constituting the serpentine flow passage sequentially smaller from the most upstream side to the most downstream side, the following effects can be obtained.
As the cooling air flows through the serpentine flow path, the cooling air receives the heat and rises in temperature by cooling the blades, so that the cooling capacity decreases. In this reference embodiment, the flow path cross-sectional area of the serpentine flow path is sequentially reduced, so that the flow velocity can be increased as the cooling air flows downstream. Therefore, even if the temperature of the cooling fluid rises as it flows downstream, a decrease in heat transfer performance can be compensated for by increasing the flow velocity, and a desired cooling capacity can be exhibited.

  The first wall portion 22A and the third wall portion 22C are arranged such that the distance therebetween is separated from the abdominal side wall portion 4A of the wing toward the back side wall portion 4B. The second wall portion 22B extends substantially parallel to the third wall portion 22C. Thereby, the 2nd flow path 12B which has a substantially triangular cross section is formed of 22 A of 2nd wall parts, 22 A of 2nd wall parts, and the back wall part 4B of a wing | blade. A third flow path 12C having a substantially rectangular cross section is formed by the second wall portion 22B, the back side wall portion 4B of the wing, the third wall portion 22C, and the abdominal side wall portion 4A of the wing.

By adopting such a configuration, the following operational effects can be obtained.
Since the first wall portion 22A and the third wall portion 22C are arranged such that the distance between them is separated from the abdominal side wall portion 4A of the wing toward the back side wall portion 4B, the first wall portion 22A and the third wall portion 22C are arranged. The cross-sectional shape formed by the wall portion 22C, the wing ventral side wall portion 4A, and the wing back side wall portion 4B is such that the wing ventral side wall portion 4A has a short side, the wing back side wall portion 4B has a long side, and the first wall portion. 22A and the 3rd wall part 22C become a substantially trapezoid made into the hypotenuse. The trapezoid is divided into a triangular shape and a quadrangular shape by the second wall portion 22B extending in parallel with the third wall portion 22C. Thereby, the rectangular shape which is not flattened as much as possible can be obtained by using the ventral side wall portion 4A of the wing which becomes the short side of the trapezoid as one side of the quadrangle. Therefore, the heat transfer area of the abdominal side wall 4A can be increased, and the cooling capacity of the blade is increased.

Further, the second wall portion 22B is connected to the first wall portion 22A without being connected to the abdominal side wall portion 4A of the wing. The effect by this is as follows.
If the second wall portion 22B is connected to the abdominal side wall portion 4A of the wing, and the abdominal side wall portion 4A of the wing is covered by the thickness of the second wall portion 22B, this covered portion interferes with cooling. Air cannot directly contact the flank side wall portion 4A of the wing, and cooling may be insufficient. Therefore, in this reference embodiment, the second wall portion 22B is connected to the first wall portion 22A without being connected to the abdominal side wall portion 4A of the wing, so that the abdominal side wall portion 4A of the wing becomes the meat of the second wall portion 22B. It was made not to be covered by the thickness. As a result, the heat transfer area in which the ventral side wall portion 4A of the blade is in direct contact with the cooling fluid without being obstructed by the second wall portion 22B can be secured, and the cooling capacity is increased.

  In the reference embodiment, the fourth to sixth wall portions 22D, 22E, and 22F are also substantially parallel to the third wall portion 22C. This is because there is an advantage that when the core for forming the cooling flow path used when casting the gas turbine blade 1 is manufactured, the die can be punched in the same direction.

[First Embodiment]
Next, a first embodiment of the present invention will be described with reference to FIG. This embodiment differs from the first reference embodiment in the extending direction of the second wall portion 24B, and the other configurations are the same. Accordingly, only the differences will be described below, and the same operation and effect will be obtained for the other points.

  The second wall portion 24B extends substantially parallel to the first wall portion 22A. Thereby, the 2nd flow path 12B which has a substantially square cross section is formed by 22 A of 1st wall parts, the back side wall part 4B of a wing | blade, the 2nd wall part 24B, and the abdominal side wall part 4A of a wing | blade. A third flow path 12C having a substantially triangular cross section is formed by the second wall portion 24B, the back wall portion 4B of the wing, and the third wall portion 22C.

By adopting such a configuration, the following operational effects can be obtained.
Since the first wall portion 22A and the third wall portion 22C are arranged such that the distance between them is separated from the abdominal side wall portion 4A of the wing toward the back side wall portion 4B, the first wall portion 22A and the third wall portion 22C are arranged. The cross-sectional shape formed by the wall portion 22C, the wing ventral side wall portion 4A, and the wing back side wall portion 4B is such that the wing ventral side wall portion 4A has a short side, the wing back side wall portion 4B has a long side, and the first wall portion. 22A and the 3rd wall part 22C become a substantially trapezoid made into the hypotenuse. The trapezoid is divided into a quadrangular shape and a triangular shape by a second wall portion 24B extending in parallel with the first wall portion 22A. Thereby, the rectangular shape which is not flattened as much as possible can be obtained by using the ventral side wall portion 4A of the wing which becomes the short side of the trapezoid as one side of the quadrangle. Therefore, the heat transfer area of the abdominal wall portion 4A can be increased, and the cooling capacity of the blade is increased.

Further, the second wall portion 24B is connected to the third wall portion 22C without being connected to the flank side wall portion 4A of the wing. The effect by this is as follows.
If the second wall portion 24B is connected to the abdominal side wall portion 4A of the wing, and the abdominal side wall portion 4A of the wing is covered by the thickness of the second wall portion 24B, this covered portion interferes with cooling. Air cannot directly contact the flank side wall portion 4A of the wing, and cooling may be insufficient. Therefore, in the present embodiment, the second wall portion 24B is connected to the third wall portion 22C without being connected to the wing belly side wall portion 4A, so that the wing belly side wall portion 4A is thicker than the second wall portion 24B. It was made not to be covered by. As a result, the heat transfer area in which the ventral side wall portion 4A of the blade is in direct contact with the cooling fluid without being obstructed by the second wall portion 24B can be secured, and the cooling capacity is increased.

[Second embodiment]
Next, a second reference embodiment of the present invention will be described with reference to FIG. This reference embodiment differs from the first reference embodiment and the first embodiment in the shape of the second wall portion, and the other configurations are the same. Accordingly, only the differences will be described below, and the same operation and effect will be obtained for the other points. In addition, unlike the first reference embodiment and the first embodiment, this reference embodiment does not divide the second cooling channel and the third cooling channel into a triangular shape and a quadrangular shape by the second wall portion. Therefore, the effect derived from these configurations is not achieved.

The second wall portion 25 has a bent shape. That is, the ventral portion 25a of the second wall portion 25 is formed in parallel with the third wall portion 22C, and the back portion 25b of the second wall portion 25 is formed in parallel with the first wall portion 22A. In this way, by forming the second wall portion 25 to be bent, the channel cross-sectional area ratio of the second cooling channel 12B and the third cooling channel 12C constituting the serpentine channel can be adjusted.
Further, in the present reference embodiment, as in the first reference embodiment and the first embodiment, the serpentine flow path constituted by the second to fourth cooling flow paths 12B, 12C, 12D, and the fifth to seventh The serpentine flow path cross-sectional area formed by the cooling flow paths 12E, 12F, and 12G is formed to become smaller in order from the most upstream side to the most downstream side, so the flow rate is increased as the cooling air flows downstream. Even if the temperature of the cooling fluid rises as it flows downstream, the decrease in heat transfer can be compensated for by increasing the flow velocity, and the desired cooling capacity can be exhibited.

DESCRIPTION OF SYMBOLS 1 Gas turbine blade 4 Blade | wing part 6 Base 12A 1st cooling flow path 12B 2nd cooling flow path 12C 3rd cooling flow path 12D 4th cooling flow path 22A 1st wall part 22B 2nd wall part 22C 3rd wall part

Claims (3)

A plurality of cooling channels extending from the base end side to the tip end side of the blade are provided from the leading edge to the rear edge of the blade, and at least two of these cooling channels are folded at the base end portion or the tip end portion. In a gas turbine blade having a connected serpentine flow path,
The serpentine channel is formed such that the cross-sectional area of the serpentine channel is gradually reduced from the cooling channel on the most upstream side to the cooling channel on the most downstream side,
A first wall section that divides a first cooling channel located on the front edge side and a second cooling channel adjacent to the rear edge side of the first cooling channel;
A second wall section defining the second cooling flow path and a third cooling flow path adjacent to the rear edge side of the second cooling flow path;
A third wall section defining the third cooling flow path and a fourth cooling flow path adjacent to the rear edge side of the third cooling flow path;
With
The serpentine flow path is formed by the second to fourth cooling flow paths so that the second cooling flow path is the most downstream side,
The first wall portion and the third wall portion are arranged such that the distance between them is separated from the ventral side of the wing toward the back side,
The second wall portion extends substantially parallel to the first wall portion,
The second flow path having a substantially rectangular cross section is formed by the first wall portion, the back side wall portion of the wing, the second wall portion, and the abdominal side wall portion of the wing,
The gas turbine blade according to claim 1, wherein the third flow path having a substantially triangular cross section is formed by the second wall portion, the abdominal side wall portion of the blade, and the third wall portion.   2. The gas turbine blade according to claim 1, wherein the second wall portion is connected to the third wall portion without being connected to a ventral side wall portion of the blade.   A gas turbine comprising the gas turbine blade according to claim 1.

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