JPH11280404A - Gas turbine cooling blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine cooling blade capable of improving heat transfer coefficient by cooling medium in a cooling passage. SOLUTION: A large number of ribs are inclined and arranged at a predetermined pitch in a cooling passage of a gas turbine cooling blade. The ribs are alternately and adversely slanted at the position where the length of the ribs is somewhat longer than nearly the central portion of the full width of the cooling passage while being brought into contact with the forward rib, and formed in such a shape that the height of its end parts which are brought into contacted with each other are increased and are generally reduced. Vortex 3b is generated in a cooling medium by the ribs, the vortex 3b is generated in both sides as shown in Figures (b), (c), and regions 6 having high heat transfer coefficient are generated in both the sides between the ribs as shown in Figure (d). In addition, a small vortex 7 are generated in the connecting parts of the ribs, so that the heat transfer coefficient is further enhanced, the regions 6 are unified, and average heat transfer coefficient is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling blade for a gas turbine, and more particularly to a structure for improving the heat transfer coefficient in a cooling passage of a moving blade or a stationary blade of the gas turbine.

[0002]

2. Description of the Related Art A cooling passage is provided inside a moving blade or a stationary blade of a gas turbine, and a cooling medium introduced into and passed through the cooling passage cools the gas turbine blade from the inside. . Such cooling prevents the gas turbine blades exposed to the high-temperature gas flowing on the outer periphery from becoming hot, thereby preventing the strength of the gas turbine blades from lowering due to the high temperature and maintaining the strength.

FIG. 7 is a longitudinal sectional view of a gas turbine cooling blade. In FIG. 7, reference numeral 1 denotes a cooling blade (moving blade), and a cooling passage 2 communicating with the inside is provided. Reference numeral 3 denotes a cooling medium, which flows into the inside of the blade from the base of the cooling blade 1 and
a, 2b, and 2c sequentially flow and flow out into the passage in which the high-temperature gas 5 flows. Reference numeral 4 denotes a rib, and a large number of ribs are arranged on the inner wall surface of each of the cooling passages 2a, 2b, and 2c so as to be described later. I try to make it.

FIGS. 5A and 5B are enlarged detailed views of the cooling passage of the conventional cooling blade 1 described above, wherein FIG. 5A is a partial plan view of the cooling passage, and FIG. In the drawing, a cooling passage 2 in a cooling blade 1
A slanted rib 4 having a constant angle θ and a pitch P is protruded at a height e over the entire width W of the cooling passage 2.
As described in FIG. 7, the cooling medium 3 is introduced into the cooling passage 2 from outside the cooling blade 1, and is discharged into the high-temperature gas 5 while sequentially cooling the inside of the cooling blade 1. At this time, rib 4
Is to generate a disturbance in the flow of the cooling medium 3 to improve the heat transfer coefficient of the cooling medium 3 flowing through the cooling passage 2.

FIG. 6 shows the cooling medium 3 of the cooling passage described above.
FIGS. 4A and 4B are diagrams schematically illustrating the flow pattern of FIG. 4 and the cooling action associated therewith, wherein FIG. 5A shows the flow direction of the cooling medium 3 when the cooling passage is viewed in a plane, and FIG. (C) shows the flow when viewed from the same perspective, and (d) shows the heat transfer coefficient distribution of the cooling passage.

As shown in these figures, the flow of the cooling medium 3 becomes a vortex 3a by the ribs 4 as shown in FIG. 1B, and flows along the inclined ribs 4 as shown in FIG. Flows in a certain direction from the upstream side to the downstream side.
For this reason, as shown conceptually as a heat transfer coefficient distribution in FIG. 6D, the region 10 having a high heat transfer coefficient is located on the upstream side where the vortex 3a asymptotically approaches the wall of the cooling passage 2 (the boundary layer is thin).
On the other hand, on the downstream side where the vortex 3a moves away from the wall of the cooling passage 2 (the boundary layer is thick), the heat transfer coefficient tends to be lower than on the upstream side, and the heat transfer coefficient becomes non-uniform depending on the location, and As average heat transfer coefficient was reduced.

[0007]

As described above, in a conventional gas turbine cooling blade, as shown in FIG.
As shown in FIG. 6D, a region 10 having a high heat transfer coefficient is generated at a portion where the vortex 3a asymptotically approaches the wall surface of the cooling passage 2 as shown in FIG.
A region where the heat transfer coefficient is reduced is generated in a portion away from the wall surface of the device, and the heat transfer coefficient becomes non-uniform, which causes a decrease in the average heat transfer coefficient.

Therefore, the present invention devises the arrangement and shape of the ribs in the cooling passages of the gas turbine cooling blades, so that a region having a high heat transfer coefficient generated by the flow of the cooling medium in the cooling passages is uniformly formed between the ribs. It is an object of the present invention to provide a structure of a cooling passage in which a cooling passage is formed so as to improve the overall average heat transfer coefficient.

[0009]

The present invention provides the following means (1) to (5) in order to solve the above-mentioned problems.

(1) It has a cooling passage communicating with the inside of the blade,
In a gas turbine cooling blade in which a number of ribs are arranged at a predetermined pitch on the inner wall of the cooling passage so as to intersect with the flow direction of the cooling medium, each rib extends from a side surface of the cooling passage to a position beyond a central portion. At the same time, the ribs are sequentially arranged so as to be alternately inclined left and right alternately with respect to the flow direction of the cooling medium, and the leading ends of the ribs beyond the central portion are in contact with the side surfaces of the upstream ribs in the flow direction of the cooling medium. A gas turbine cooling blade characterized by the above-mentioned.

(2) In the invention of the above (1), the height of the rib is such that a tip of the rib passing over the center of the cooling passage is higher than the other end and decreases toward the other end. And gas turbine cooling blades.

(3) It has a cooling passage communicating with the inside of the blade,
In a gas turbine cooling blade in which a number of ribs are arranged at a predetermined pitch on the inner wall of the cooling passage so as to intersect with the flow direction of the cooling medium, a predetermined position in the longitudinal direction of the rib is substantially orthogonal to the rib. A gas turbine cooling blade characterized by being erected as described above.

(4) The gas turbine cooling blade according to the invention (3), wherein the pins are provided at predetermined intervals on ribs arranged.

(5) The gas turbine cooling blade according to the above (3) or (4), wherein the pins are connected to wall surfaces on the back side and the abdomen side of the cooling passage.

In (1) of the present invention, the ribs are alternately inclined in reverse with respect to the flow direction of the cooling medium, and are in contact with the side surfaces of the front ribs slightly closer to the center than the center of the cooling passage. Therefore, the flow of the cooling medium alternately generates vortices flowing on opposite sides along ribs inclined in opposite directions, and the vortices flow while sequentially turning between the front and rear ribs arranged at a predetermined pitch, and the cooling passage between the ribs Regions with a high heat transfer coefficient are formed on both sides, and regions with a high heat transfer coefficient are not offset as in the prior art. The high heat transfer region is made uniform and the overall average heat transfer coefficient is improved.

Also, as in (2) of the present invention, the heights of the ribs are higher at the ends where they come into contact with each other, and the heights of the side surfaces are gradually lower. A vortex is generated, and the small vortex also promotes the action of increasing the heat transfer coefficient.

In (3) of the present invention, since the pins are erected on each of the ribs, a region having a high heat transfer coefficient is generated due to the eddy current as in the prior art. A vortex flow also occurs on the side, and this flow flows along the slope of the rib, and in the region where the conventional high heat transfer coefficient is unlikely to occur, the flow generated by this pin generates a region with a high heat transfer coefficient, and the heat transfer coefficient And the average heat transfer coefficient of the whole is improved.

As in (4) of the present invention, the above-mentioned pins may be provided at predetermined intervals in addition to all the ribs, and the high heat transfer region caused by the flow generated by the pins may be appropriately adjusted as necessary. it can. Furthermore, in (5) of the present invention, since each pin is provided so as to be connected to the back side and the abdomen side, this pin can also be used as a reinforcing member inside the cooling passage.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a gas turbine cooling blade according to a first embodiment of the present invention, wherein (a)
Is a partially enlarged plan view of the cooling passage, (b) is a side view thereof,
(C) is a perspective view thereof. In these figures, reference numeral 11 denotes a number of ribs, which are fixed at an angle θ, on the inner wall surface of the cooling passage 2.
Inclined at a constant pitch P with respect to the main flow direction of the cooling medium 3,
The inclinations are alternately arranged left and right with opposite inclinations.

The ribs 11 are also arranged to be inclined to a position of Wa smaller than W with respect to the entire width W of the cooling passage 2, and the height thereof is set to e at a position of Wa slightly closer to the side from the center portion. The height decreases from the position toward the outside (downstream side), so that f is lower than e at the end.

The rib 11 having such a shape comes into contact with the side surface of the upstream inclined rib 11 at the tip end of the height e, and at the contact portion, it is higher than the upstream rib 11 and protrudes from it. Such an inclined rib 1
1 are alternately and reversely inclined so that the high portion of the height e is in contact with the vicinity of the central portion of the side surface of the upstream rib 11, and such a large number of ribs 11 are moved in the main flow direction of the cooling medium 3 in the cooling passage 2. Many are arranged at the pitch P.

FIG. 2 shows a flow pattern and a heat transfer coefficient distribution of the cooling medium in the first embodiment. (A) is a plan view of the flow pattern, (b) is a side view thereof, and (c) is a perspective view thereof. And (d) is a heat transfer coefficient distribution diagram. As shown in these figures, the ribs 11 are alternately arranged at the center in the opposite direction and inclined in the opposite direction, so that a vortex 3b is generated, which flows from the center of the cooling passage 2 to both outsides.

The vortex 3b turns into a vortex swirling from the space between the ribs 11 arranged at an interval of pitch P on both sides of the cooling passage 2 toward the next downstream space.
The shape 1 is a shape in which the height becomes lower from the height e to the height f. Since there is a difference in height at the ends where the ribs are in contact with each other, small eddies 7 are generated at the corners of the rib 11 having this height e. This small vortex 7 also
Since the contact portions of the ribs are alternately formed on the left and right sides, the ribs occur on both sides.

According to the first embodiment of the above configuration, as in the conventional cooling structure, a region 6 having a high heat transfer coefficient is formed on the upstream side of the generated vortex 3b as shown in FIG. However, since the vortex 3b is generated on both outer sides, this region 6
Also occur on both sides of the space formed by the arrangement of the ribs 11.

Further, since the rib shape is changed so as to decrease from the height e to the height f, small eddies 7 generated at the rib corners of the joints of the ribs are also generated on both sides, and the above-described high heat transfer coefficient is obtained. The generation of the region 6 can be promoted, and the improvement of the heat transfer coefficient can be further improved.

With respect to the height dimensions e and f of the rib 11, the same effect can be expected even when e = f, and the values of e and f are selected so that the required heat transfer coefficient is obtained. What is necessary is just to adjust the degree to which a high heat transfer coefficient can be obtained.

As described above, according to the first embodiment,
By inclining the ribs 11 and arranging the inclinations alternately so that the tip portions are in contact with the rib side surface on the upstream side and the dimensions are changed to e to f, the region 6 having a high heat transfer coefficient is formed.
To increase the heat transfer rate evenly on both sides of the cooling passage 2, and also to promote the generation of a region having a high heat transfer rate by the small vortex 7 generated at the corner of the joint, so that the overall average heat transfer of the cooling blades is increased. The rate is improved.

FIG. 3 shows a gas turbine cooling blade according to a second embodiment of the present invention, wherein (a) is a partially enlarged plan view of a cooling passage, (b) is a side view thereof, and (c) is a perspective view thereof. It is. In these drawings, the shape of the second embodiment of the present invention is basically a rib shape and its arrangement based on the shape of the prior art, and further increases the heat transfer coefficient in a region having a low heat transfer coefficient. It is.

In these figures, a pin 8 is mounted on a rib 4 at a position of a dimension C substantially at the center with respect to the entire width W of the cooling passage 2. The pins 8 have a diameter d and a height h, and are arranged on all the ribs 4 in the figure. However, the pins 8 may not be arranged on all the ribs 4 but may be arranged every several pieces. Good thing.

FIG. 4 shows the flow pattern and heat transfer coefficient distribution of the cooling medium in the second embodiment described above.
(A) is a plan view of a flow pattern, (b) is a side view thereof, (c) is a perspective view thereof, and (d) is a view showing a heat transfer coefficient distribution. As shown in these figures, a turbid flow 3a generated by the rib 4 is formed, and the turbulent flow 3a generates a region 10 having a high heat transfer coefficient as shown in FIG. This area 10
Is the same operation as the conventional example.

In addition to the above, due to the presence of the pin 8, a vortex 12 generated by the pin 8 is formed on the trailing edge side of the pin 8, and the vortex 12 flows along the inclination of the rib 4, and
On the side opposite to 0, a region 1 having a high heat transfer coefficient as shown in FIG.
1 is formed. Therefore, the heat transfer coefficient of the region 11 can be adjusted by arbitrarily determining the diameter d and the height h of the pin 8.

When the width W of the cooling passage 2 is large,
A plurality of pins 8 can be arranged along the longitudinal direction of the rib 4, and in this case, a region having a high heat transfer coefficient can be enlarged.

In the second embodiment, in the case of the pin standing method, for example, the back side and the abdomen side of the wing are connected by a pin 8, and as a reinforcing material for a thin-walled hollow wing, it also serves as cooling promotion. It is preferable to use them. Also in the second embodiment, as in the first embodiment, the average heat transfer coefficient can be improved by increasing the region where the heat transfer coefficient is high.

[0034]

The gas turbine cooling blade of (1) of the present invention has a cooling passage communicating with the inside of the blade, and a number of ribs are provided on the inner wall of the cooling passage so as to intersect the flow direction of the cooling medium. In the gas turbine cooling blades arranged at the pitch of
Each of the ribs extends from a side surface of the cooling passage to a position beyond a central portion, and is disposed in such a manner as to be alternately inclined left and right alternately with respect to the flow direction of the cooling medium, and a leading end of each of the ribs extending beyond the central portion of the rib. Are characterized by being in contact with the side surfaces of the upstream ribs in the flow direction of the cooling medium. Also, (2)
Is characterized in that, in the invention of the above (1), the height of the rib is shaped such that the tip beyond the center of the cooling passage is higher than the other end and decreases toward the other end. According to such a configuration, a region having a high heat transfer coefficient is not uniformly formed as in the related art, and a region having a high heat transfer coefficient is uniformly formed in the cooling passage, so that the overall average heat transfer coefficient is improved.

The gas turbine rotor blade (3) of the present invention has a cooling passage communicating with the inside of the blade, and a plurality of ribs are formed on the inner wall of the cooling passage at a predetermined pitch so as to intersect the flow direction of the cooling medium. In the gas turbine cooling blade provided in the above, a pin is provided upright at a predetermined position in the longitudinal direction of the rib so as to be substantially orthogonal to the rib. Also, (4)
In the invention of the above (3), the pins are provided at predetermined intervals on the ribs to be arranged, and in (5), in the invention of the above (3) or (4), the pins are located on the back side of the cooling passage. And is connected to the ventral wall. With such a configuration, in addition to the generation of a region having a high heat transfer coefficient as in the conventional case, the region having a high heat transfer coefficient is also formed in the region of the conventional heat transfer coefficient by a flow generated downstream of the pin. And can increase the overall average heat transfer coefficient.

[Brief description of the drawings]

FIG. 1 shows a gas turbine cooling blade according to a first embodiment of the present invention, wherein (a) is a partially enlarged plan view of a cooling passage,
(B) is a side view, and (c) is a perspective view.

2A and 2B show a flow of a cooling medium of a gas turbine cooling blade according to a first embodiment of the present invention, wherein FIG. 2A is a plan view of a flow pattern, FIG. 2B is a side view thereof, and FIG. FIG. 3D is a heat transfer coefficient distribution diagram.

FIG. 3 shows a gas turbine cooling blade according to a second embodiment of the present invention, wherein (a) is a partially enlarged plan view of a cooling passage,
(B) is a side view, and (c) is a perspective view.

4A and 4B show a flow of a cooling medium of a gas turbine cooling blade according to a second embodiment of the present invention, wherein FIG. 4A is a plan view of a flow pattern, FIG. 4B is a side view thereof, and FIG. FIG. 3D is a heat transfer coefficient distribution diagram.

5A and 5B show a conventional gas turbine cooling blade, wherein FIG. 5A is a partially enlarged plan view of a cooling passage, and FIG. 5B is a perspective view thereof.

6A and 6B show a flow of a cooling medium of a conventional gas turbine cooling blade. FIG. 6A is a plan view of a flow pattern, FIG. 6B is a side view thereof, FIG. 6C is a perspective view thereof, and FIG. It is a distribution map.

FIG. 7 is a longitudinal sectional view of a conventional gas turbine cooling blade.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling blade 2 Cooling passage 3 Cooling medium 3a, 3b Eddy flow 4,11 Rib 5 High temperature gas 6,10,11 Area with high heat transfer coefficient 7 Small eddy current 8 Pin 12 Flow

Continued on the front page (72) Inventor Kenichiro Takeishi 2-1-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Kiyoshi Suenaga 2-1-1, Niihama, Arai-machi, Takasago-shi, Hyogo Mitsubishi Heavy Industries Co., Ltd. Takasago Factory

Claims (5)

[Claims] 1. A gas turbine cooling blade having a cooling passage communicating with the inside of a blade, wherein a plurality of ribs are arranged at a predetermined pitch on an inner wall of the cooling passage so as to intersect with a flow direction of a cooling medium. Each rib extends from the side surface of the cooling passage to a position beyond the central portion, and is arranged in such a manner that it is alternately inclined left and right alternately with respect to the flow direction of the cooling medium, and the tip of the rib beyond the central portion is A gas turbine cooling blade that is in contact with a side surface of a upstream rib in a flow direction of a cooling medium. 2. The gas turbine according to claim 1, wherein the height of the rib is such that a tip of the rib passing through the center of the cooling passage is higher than the other end and decreases toward the other end. Cooling wings. 3. A gas turbine cooling blade having a cooling passage communicating with the inside of a blade, wherein a plurality of ribs are arranged on the inner wall of the cooling passage at a predetermined pitch so as to intersect with a flow direction of a cooling medium. A gas turbine cooling blade, wherein a pin is provided upright at a predetermined position in a longitudinal direction of the rib so as to be substantially orthogonal to the rib. 4. The gas turbine cooling blade according to claim 3, wherein said pins are provided at predetermined intervals on ribs arranged. 5. The gas turbine cooling blade according to claim 3, wherein the pins are connected to wall surfaces on the back side and the ventral side of the cooling passage.