Cooling structure for turbine blade

Abstract

The invention relates to a cooling structure of a turbine blade, which comprises a cooling channel, and the cooling channel comprises an inlet channel, a first channel, a second channel and a third channel, the first bent channel is connected with the inlet channel and the first channel, the second bent channel is connected with the first channel and the second channel, and the third bent channel is connected with the second channel and the third channel. And a fabrication hole coupling the first curved channel and the third curved channel, where the third curved channel has an outer profile curve proximate the first curved channel, where the fabrication hole is straight, and where the third curved channel has an outer profile curve proximate the first curved channel. The distance between the intersection point of the center line of the auxiliary hole and the outer contour curve of the third bent channel and the line penetrating through the lowest point of the third bent channel is larger than zero.

Description

Technical Field

[0001] This invention relates to the field of turbine structures, and more particularly to a cooling structure for turbine blades. Background Technology

[0002] High-pressure turbine rotor blades are typically designed as cooling structures with internal multi-cavity rotating channels. For multi-cavity rotating channels, the blade cores are narrow and long. In order to facilitate the positioning of adjacent cavity cores and subsequent core removal, a process hole structure is usually designed between the inlet channel and the intermediate channel to connect adjacent cavities.

[0003] Due to manufacturing limitations, some process holes cannot be sealed, resulting in the presence of process hole structures within the finished blade cavity. The presence of these process holes allows cool air to flow from the inlet channel into adjacent channels, merging and mixing with the original cooling airflow. This affects both the flow pattern of the original airflow and the flow losses within the blade cavity, thus impacting the cooling design effectiveness. Summary of the Invention

[0004] To address the flow loss caused by airflow mixing, this invention proposes a cooling structure for turbine blades. The resulting cooling structure with process holes exhibits minimal local losses, allowing the cooling air within the process holes to merge into the original cooling airflow at a favorable angle. This results in smooth flow lines, minimal mixing of the two airflows, and minimal separation of the internal cooling airflow, thereby reducing overall flow losses.

[0005] Specifically, this cooling structure for turbine blades includes cooling channels comprising separate inlet channels and sequentially arranged first, second, and third channels, and includes a first curved channel connecting the inlet channels and the first channel, a second curved channel connecting the first and second channels, and a third curved channel connecting the second and third channels; and a process hole connecting the first and third curved channels, wherein the third curved channel has an outer contour curve close to the first curved channel, wherein the process hole is straight, and wherein the distance between the intersection of the centerline of the process hole and the outer contour curve of the third curved channel and the line passing through the lowest point of the third curved channel is greater than zero.

[0006] In embodiments of the present invention, the first channel, the second channel, and the third channel are straight channels that are parallel to each other.

[0007] In an embodiment of the present invention, the first curved channel has a profile close to the second curved channel. The profile has a first profile curve, a second profile curve, and a third profile curve. The first profile curve is close to the inlet channel, the third profile curve is close to the first channel, and the second profile curve is located between the first profile curve and the third profile curve. The second profile curve bends toward the outer profile curve, and the third profile curve bends away from the outer profile curve.

[0008] Preferably, the distance between the third contour curve and the outer contour curve of the third curved channel is equal.

[0009] In one example of the invention, one end of the process hole is located on the second profile curve of the first curved channel.

[0010] In another example of the invention, the angle between the centerline of the process hole and the height direction of the turbine blade is less than 45°.

[0011] In another example of the invention, the process hole is inclined from the pressure side of the turbine blade toward the suction side of the turbine blade.

[0012] The detailed design of the above-mentioned process hole structure can reduce the impact of overall flow loss.

[0013] Preferably, the cross-sectional area of ​​the third curved channel is larger than the cross-sectional areas of the second and third channels.

[0014] Furthermore, the cross-sectional area of ​​the lowest point of the outer contour curve of the third curved channel is greater than 110% of the cross-sectional areas of the second and third channels.

[0015] The design of the aforementioned channel structure helps to reduce the impact of overall flow loss.

[0016] Additional features and advantages of the cooling structure for turbine blades described herein will be set forth in the detailed description below, and will be recognized by those skilled in the art either by the following description or by practice of the embodiments described herein, including the detailed description below and the accompanying drawings. Attached Figure Description

[0017] With reference to the above objectives, the technical features of the present invention are clearly described in the following embodiments, and its advantages are apparent from the following detailed description with reference to the accompanying drawings, which illustrate preferred embodiments of the invention by way of example, without limiting the scope of the inventive concept.

[0018] Figure 1 This is a schematic diagram of a cooling structure for turbine blades according to an embodiment of the present invention;

[0019] Figure 2This is a partially enlarged view of a cooling structure for turbine blades according to an embodiment of the present invention;

[0020] Figure 3 This is a cross-sectional schematic diagram of a cooling structure for turbine blades according to an embodiment of the present invention, viewed from the side of the turbine blade, wherein; and

[0021] Figure 4 This is a schematic diagram of the third curved channel of a cooling structure for turbine blades according to an embodiment of the present invention.

[0022] Figure label:

[0023] 1 Entrance Channel

[0024] 2 First Channel

[0025] 3 Second Channel

[0026] 4 Third Channel

[0027] 5 First Curved Channel

[0028] 6 Second Curved Channel

[0029] 7 Third Curved Channel

[0030] 8 process holes

[0031] 9 blades

[0032] 10 Pressure Side

[0033] 11 Suction Side

[0034] f1 First contour curve

[0035] f2 Second Profile Curve

[0036] f3 Third contour curve

[0037] f4 outer contour curve

[0038] f5 vertical line

[0039] Cross-sectional area of ​​the second channel of A1

[0040] Cross-sectional area of ​​the third channel of A2

[0041] The cross-sectional area of ​​the lowest point through which the third curved channel of A3 passes.

[0042] C intersection point

[0043] D lowest point Detailed Implementation

[0044] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to better understand the purpose, features and advantages of the present invention.

[0045] The directional terms used in this article, such as "up," "down," "left," "right," "horizontal," and "vertical," are based on... Figure 1 It is defined by the view.

[0046] Furthermore, the terms "profile curve" and similar terms used in this article are also based on... Figure 1 It is described using a view.

[0047] Unless otherwise specified, all curves used in this paper are assumed to have a radius of curvature greater than zero everywhere except at their endpoints (i.e., the curves do not "twist"). Therefore, the "distance" between two curves is defined as follows: taking a point on each curve such that the slopes of the tangents passing through these two points are equal, the distance between these two points can be considered the distance between the two curves. Note that this distance between the curves can vary. When the distances between any pair of points satisfying the above requirement are equal, the distance between the curves can be considered equal everywhere.

[0048] Furthermore, the "cross-sectional area" at a certain point in the channel can be defined as the area perpendicular to the passage. Figure 1 The drawing contains the area of ​​the intersection between the plane at the aforementioned distance and the curved channel. Similarly, the cross-sectional area of ​​the channel can also vary.

[0049] Figure 1 A schematic diagram of a cooling structure for a turbine blade according to an embodiment of the present invention is shown. The cooling structure is disposed within the blade body and includes cooling channels designed in a serpentine pattern to increase the cooling volume. Specifically, the cooling channels include an inlet channel 1, a first channel 2, a second channel 3, a third channel 4, a first curved channel 5, a second curved channel 6, and a third curved channel 7, which are separated from each other. Cooling air can enter from the inlet channel 1 to cool the blade. The inlet channel 1 may optionally be a straight channel.

[0050] As shown in the figure, the first channel 2, the second channel 3, and the third channel 4 are arranged sequentially from right to left, and the first channel 2, the second channel 3, and the third channel 4 can be constructed as straight channels parallel to each other. It should be understood that in other embodiments, the first channel 2, the second channel 3, and the third channel 4 may not be parallel to each other.

[0051] The cooling channel also includes a first curved channel 5, a second curved channel 6, and a third curved channel 7. As shown in the figure, the first curved channel 5 connects the inlet channel 1 and the first channel 2, the second curved channel 6 connects the first channel 2 and the second channel 3, and the third curved channel 7 connects the second channel 3 and the third channel 4. In this configuration, cooling air can sequentially pass from the inlet channel 1 through the first curved channel 5, the first channel 2, the second curved channel 6, the second channel 3, the third curved channel 7, and the third channel 4 to efficiently cool most of the blade volume. The first channel 2, the second channel 3, and the third channel 4 can be configured as straight channels parallel to each other, and the first curved channel 5 and the third curved channel 7 can be configured as adjacent channels.

[0052] In this embodiment, for ease of design, the second curved channel 6 and the third curved channel 7 are formed in a U-shape and are symmetrical with respect to the first channel 2 and the second channel 3, and the second channel 3 and the third channel 4, respectively. This symmetrical curved shape allows the second curved channel 6 and the third curved channel 7 to have an axis of symmetry (e.g., the third curved channel 7 has an axis of symmetry f5 as described below, this virtual line passing through the lowest point of the third curved channel 7). It should be understood that in other embodiments, the second curved channel 6 and the third curved channel 7 can have other shapes, and may not even be continuously curved, and they can be asymmetrical, as long as the third curved channel 7 has a lowest point. For ease of understanding, the U-shaped second curved channel 6 and the third curved channel 7 will be described below as exemplary shapes.

[0053] In this embodiment, the first curved channel 5 has a profile close to the third curved channel 7. Specifically, the profile has a first profile curve f1, a second profile curve f2, and a third profile curve f3. The first profile curve f1 is close to the inlet channel 1, the third profile curve f3 is close to the first channel 2, and the second profile curve f2 is located between the first profile curve f1 and the third profile curve f3. Similarly, the third curved channel 7 has an outer profile curve f4 close to the first curved channel 5, wherein the second profile curve f3 curves toward the outer profile curve f4 (i.e., bulges toward the outer profile curve f4), and the third profile curve f3 curves away from the outer profile curve f4.

[0054] Preferably, the distance between the third contour curve f3 and the outer contour curve f4 of the third curved channel 7 is equal everywhere (from...). Figure 2 (This can be better seen in the image). This design allows the cooling air to cool the inside of the blades more evenly, improving cooling efficiency.

[0055] Reference Figure 1 and further refer to Figure 2The diagram shows a process hole 8 in the cooling structure. This process hole 8 is typically a circular hole that connects the first curved channel 5 and the third curved channel 7. The process hole 8 allows cooling air to flow from the first curved channel 5 into the adjacent third curved channel 7, where it merges and mixes with the original cooling airflow. This affects the flow pattern of the original airflow and increases the flow loss within the blade cavity, thus impacting the cooling design effectiveness.

[0056] To address the aforementioned issues, improvements to process orifice 8 are described below, which reduce the impact of process orifice 8 on flow losses.

[0057] Reference Figure 2 In this embodiment, the process hole 8 is straight and has a center line. The distance δ between the intersection point C of the center line of the process hole 8 and the outer contour curve f4 of the third curved channel 7 and the vertical line f5 passing through the lowest point D of the third curved channel 7 is greater than zero.

[0058] Preferably, in one example, one end of the process hole 8 is located on the second profile curve f2 of the first curved channel 5.

[0059] Preferably, in one example, the angle α between the centerline of the process hole 8 and the height direction of the turbine blade (i.e., the vertical line f5) is less than 45°.

[0060] Reference Figure 3 In one example, the process hole 8 can be tilted from the pressure side 10 of the turbine blade 9 toward the suction side 11 of the turbine blade 9, preferably with an inclination angle β < 60°.

[0061] The above design allows the cooling air in the process hole 8 to merge into the original cooling airflow at a better angle, resulting in smooth flow lines, minimal mixing of the two airflows, inconspicuous separation of internal cooling airflow, and reduced overall flow loss.

[0062] Reference Figure 4 In a further preferred example, the cross-sectional area of ​​the third curved channel 7 can be greater than the cross-sectional area A1 of the second channel 3 and the cross-sectional area A2 of the third channel 4. Furthermore, the cross-sectional area A3 of the third curved channel 7 passing through the lowest point of the outer contour curve f4 (i.e., passing through the vertical line f5) is greater than 110% of the cross-sectional areas A1 and A2 of the first and second channels (i.e., A2 > 1.1 * A1, A2 > 1.1 * A3).

[0063] While the structure of the present invention has been described above with reference to preferred embodiments, those skilled in the art should recognize that the above examples are merely illustrative and should not be construed as limiting the invention. Therefore, modifications and variations can be made to the present invention, and all such modifications and variations will fall within the scope of this application.

Claims

1. A cooling structure for turbine blades, comprising: The cooling channel includes separate inlet channels and sequentially arranged first, second, and third channels, and includes a first curved channel connecting the inlet channels and the first channel, a second curved channel connecting the first channel and the second channel, and a third curved channel connecting the second channel and the third channel. Process hole, the process hole connecting the first curved channel and the third curved channel, The third curved channel has an outer contour curve that is close to that of the first curved channel. Wherein, the process hole is straight, and Wherein, the distance between the intersection of the centerline of the process hole and the outer contour curve of the third curved channel and the line passing through the lowest point of the third curved channel is greater than zero.

2. The cooling structure for turbine blades as described in claim 1, characterized in that, The first channel, the second channel, and the third channel are straight channels that are parallel to each other.

3. The cooling structure for turbine blades as described in claim 1, characterized in that, The first curved channel has a profile close to the second curved channel. This profile has a first profile curve, a second profile curve, and a third profile curve. The first profile curve is close to the inlet channel, the third profile curve is close to the first channel, and the second profile curve is located between the first profile curve and the third profile curve. The second contour curve bends toward the outer contour curve, and the third contour curve bends away from the outer contour curve.

4. The cooling structure for turbine blades as described in claim 1, characterized in that, The distance between the third contour curve and the outer contour curve of the third curved channel is equal.

5. The cooling structure for turbine blades as described in claim 3, characterized in that, One end of the process hole is located on the second contour curve of the first curved channel.

6. The cooling structure for turbine blades as described in claim 5, characterized in that, The angle between the centerline of the process hole and the height direction of the turbine blade is less than 45°.

7. The cooling structure for turbine blades as described in claim 1, characterized in that, The process hole is inclined from the pressure side of the turbine blade toward the suction side of the turbine blade.

8. The cooling structure for turbine blades as described in claim 1, characterized in that, The cross-sectional area of ​​the third curved channel is larger than that of the second channel and the third channel.

9. The cooling structure for turbine blades as described in claim 1, characterized in that, The cross-sectional area of ​​the third curved channel at the lowest point of its outer contour curve is greater than 110% of the cross-sectional areas of the second and third channels.

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