CN117967407A - A cooling structure for the trailing edge of a turbine moving blade - Google Patents

Abstract

The present application provides a cooling structure for the trailing edge of a turbine moving blade, which belongs to the technical field of gas turbine blade cooling, and specifically comprises a cooling chamber located inside the trailing edge of the turbine moving blade, a plurality of column ribs being arranged in the cooling chamber, an air inlet passage being arranged on one side of the cooling chamber, the air inlet passage being connected to an air inlet at the root of the blade, a trailing edge slit being arranged on the other side of the cooling chamber, a plurality of strip-shaped micro-ribs being arranged on the inner wall surface of the pressure surface and/or the suction surface of the blade corresponding to the cooling chamber, the strip-shaped micro-ribs protruding from the inner wall surface of the cooling chamber, the strip-shaped micro-ribs passing through the gap area between the column ribs, and the strip-shaped micro-ribs being located on the side of the column ribs facing away from the trailing edge of the blade; cold air enters the air inlet passage from the air inlet along the blade height direction, and then flows out from the trailing edge slit after passing through the strip-shaped micro-ribs and column ribs in the cooling chamber, the strip-shaped micro-ribs are used to generate flow resistance to the airflow entering the cooling chamber, reduce the vortex in the air inlet passage close to the blade tip area, and improve the uniformity of heat exchange at the trailing edge of the turbine moving blade.

Description

A cooling structure for the trailing edge of a turbine moving blade

Technical Field

The present application relates to the field of gas turbine blade cooling, and in particular to a turbine moving blade trailing edge cooling structure.

Background technique

As an advanced power device, gas turbines are widely used in power generation, aviation propulsion, chemical industry and other fields. Under the background of "dual carbon", the proportion of heavy-duty gas turbine combined cycle power generation is increasing year by year due to its higher efficiency. At present, the turbine inlet temperature of advanced heavy-duty gas turbines is far higher than the melting point of their materials. Turbine blades usually need to be designed with complex cooling structures to ensure the normal operation of the blades at such high temperatures.

At present, the trailing edge of turbine blades usually adopts column rib structure to enhance heat exchange. The column rib structure connects the two side end walls (pressure side and suction side) to disturb the incoming cold air. The horseshoe vortex system formed by the stagnation of the cold air flow through the leading edge of the column rib enhances the heat exchange of the two side end walls. The unstable vortex shedding at the trailing edge of the column rib also increases the turbulence of the internal flow and enhances the heat exchange in the downstream area. While enhancing the heat exchange of the internal cooling channel, the column rib also plays a certain supporting role for the thinner trailing edge of the blade, enhancing the strength of the trailing edge of the blade.

The cooling air in the trailing edge cavity of the turbine moving blade is usually injected from the blade root, first flows along the blade height direction, then is deflected, flows through the cooling channel arranged with column ribs, flows along the blade axis, and finally is discharged through the slit of the trailing edge of the blade to form an air film to protect the suction surface of the blade. This cooling structure also has certain shortcomings. When the cooling air flows through the blade tip area, a large vortex is often formed in this area. This flow structure also causes uneven flow distribution in the trailing edge area, resulting in a lower flow to the blade tip, insufficient cooling of the blade tip, uneven cooling of the turbine blade, large thermal stress and other problems. The resulting blade trailing edge ablation problem is an important factor in blade failure.

The larger blade size of heavy-duty gas turbines usually also leads to higher Reynolds numbers and Biot numbers. Especially at high Biot numbers, the thermal stress problem caused by uneven cooling of the blades becomes more prominent. In order to cope with the increasing turbine inlet temperature and limited cooling air flow, a more efficient and uniform cooling blade trailing edge cooling structure is urgently needed.

Summary of the invention

In view of this, the present application provides a turbine blade trailing edge cooling structure, which solves the problems in the prior art and improves the uniformity of heat exchange at the turbine blade trailing edge.

The present application provides a turbine blade trailing edge cooling structure that adopts the following technical solution:

A turbine blade trailing edge cooling structure, comprising a cooling chamber located inside the turbine blade trailing edge, a plurality of column ribs arranged in the cooling chamber, an air inlet passage arranged on one side of the cooling chamber, the air inlet passage being in communication with an air inlet of a blade root, a trailing edge slit arranged on the other side of the cooling chamber, a plurality of strip-shaped micro-ribs arranged on the inner wall surface of the cooling chamber corresponding to the pressure surface and/or the suction surface of the blade, the strip-shaped micro-ribs protruding from the inner wall surface of the cooling chamber, the strip-shaped micro-ribs passing through the gap area between the column ribs, and the strip-shaped micro-ribs located on the side of the column ribs facing away from the blade trailing edge;

Among them, cold air enters the air inlet channel from the air inlet along the blade height direction, and then flows out from the trailing edge slit after passing through the strip micro-ribs and column ribs in the cooling chamber. The strip micro-ribs are used to generate flow resistance to the airflow entering the cooling chamber, thereby reducing the vortex in the air inlet channel near the blade top area.

Optionally, the length direction of the strip-shaped micro-ribs is inclined relative to the height direction of the blade, and the inclination angles of different strip-shaped micro-ribs relative to the height direction of the blade are the same or different.

Optionally, the strip-shaped micro-ribs in the portion close to the blade top region gradually incline from the blade top to the blade root side in the direction from the leading edge to the trailing edge of the blade;

The strip-shaped micro-ribs near the root area of the blade gradually incline from the root of the blade to the tip of the blade in the direction from the leading edge to the trailing edge of the blade.

Optionally, the cooling chamber is provided with a plurality of column rib rows distributed in sequence along the extension direction from the leading edge to the trailing edge of the blade, and at least part of the strip-shaped micro-ribs correspond to the column ribs of different column rib rows within the extension range.

Optionally, the cooling chamber is provided with a plurality of rows of column ribs distributed along the extension direction from the blade top to the blade root, and the column rib rows where the column ribs of different column rib columns corresponding to the same strip-shaped micro-rib are located are different.

Optionally, the strip-shaped micro-rib passes through a gap between two adjacent column ribs in the same column rib row, and there are strip-shaped micro-ribs between two adjacent column ribs in the same column rib row.

Optionally, the cooling chamber is provided with a plurality of columns of column ribs distributed in sequence along the extension direction from the leading edge to the trailing edge of the blade, each column rib column is provided with the strip-shaped micro-ribs on the side facing the leading edge of the blade, and the number of the strip-shaped micro-ribs corresponding to each column rib column is at least one.

Optionally, the number of the strip-shaped micro-ribs corresponding to each column rib row is multiple, and the inclination angles of the multiple strip-shaped micro-ribs corresponding to each column rib row relative to the blade height direction are the same or different.

Optionally, the cooling chamber is provided with a plurality of column rib groups distributed in sequence along the extension direction from the leading edge to the trailing edge of the blade, each group of the column rib groups includes a first column rib row and a second column rib row, the first column rib row and the second column rib row both include a plurality of the column ribs distributed along the height direction of the blade, the column ribs of the first column rib row and the second column rib row are staggered, the column ribs in the same row of all the first column rib rows of different column rib groups are at the same height position of the blade, and the column ribs in the same row of all the second column rib rows of different column rib groups are at the same height position of the blade.

Optionally, the ratio of the height of the strip-shaped micro-ribs protruding from the inner wall surface of the cooling chamber to the height of the column ribs is less than 0.3.

In summary, this application includes the following beneficial technical effects:

In the present application, the strip micro-ribs are located in the upstream area of the column ribs. When the fluid flows through the strip micro-ribs, the near-wall disturbance generated by the strip micro-ribs can strengthen the horseshoe vortex strength at the leading edge of the column ribs, enhance heat transfer, and improve the heat transfer coefficient of the cooling structure.

The strip-shaped micro-ribs of the present application are used to generate flow resistance to the air flow entering the cooling chamber, adjust the cold air flow distribution in the blade height direction, reduce the vortex in the inlet channel near the blade top area and the separation vortex located at the air inlet near the blade root, reduce the low heat exchange area at the original blade top and blade root, make the air film flowing out at different blade height positions at the trailing edge split more uniform, and also reduce the separation caused by uneven upstream flow and the channel formed by the cold flow entering the trailing edge split step, thereby improving the air film cooling efficiency at the trailing edge split and reducing the thermal stress caused by uneven cooling, thereby achieving the purpose of uniform heat exchange on the trailing edge of the blade and extending the service life of the blade.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of the air flow direction of the cooling structure when no strip-shaped micro-fins are provided;

FIG. 2 is a schematic diagram of the airflow direction of the cooling structure when strip-shaped micro-ribs are provided in the present application.

Explanation of the reference numerals: 1. Inlet passage; 11. Inlet port; 12. Swirl vortex; 2. Cooling chamber; 21. Column rib; 22. Strip micro-rib; 23. First column rib row; 24. Second column rib row; 3. Trailing edge slit; 31. slit step; 32. Air film; 4. Blade top; 5. Blade root.

Detailed ways

The embodiments of the present application are described in detail below with reference to the accompanying drawings.

The following describes the implementation methods of the present application through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and/or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and/or practice the method. In addition, other structures and/or functionalities other than one or more of the aspects described herein can be used to implement this device and/or practice this method.

It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show the components related to the present application rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described may be practiced without these specific details.

An embodiment of the present application provides a turbine blade trailing edge cooling structure.

As shown in Figures 1 and 2, a cooling structure for the trailing edge of a turbine moving blade comprises a cooling chamber 2 located inside the trailing edge of the turbine moving blade, wherein a plurality of column ribs 21 are arranged in the cooling chamber 2, an air inlet passage 1 is arranged on one side of the cooling chamber 2, wherein the air inlet passage 1 is connected to an air inlet 11 of a blade root 5, and a trailing edge slit 3 is arranged on the other side of the cooling chamber 2, wherein the trailing edge slit 3 comprises a plurality of slit steps 31 arranged at intervals along the height direction of the blade, and the air inlet passage 1, the cooling chamber 2 and the trailing edge slit 3 are sequentially distributed along the direction from the leading edge to the trailing edge of the blade. The present application provides a plurality of strip-shaped micro-ribs 22 on the inner wall surface of the pressure surface and/or the suction surface of the blade corresponding to the cooling chamber 2, wherein the strip-shaped micro-ribs 22 protrude from the inner wall surface of the cooling chamber 2, wherein the strip-shaped micro-ribs 22 pass through the gap area between the column ribs 21, and wherein the strip-shaped micro-ribs 22 are located on the side of the column ribs 21 facing away from the trailing edge of the blade. The solid arrows in Figures 1 and 2 are cooling air paths. When the strip micro-ribs 22 are not provided, cooling air enters the air inlet passage 1 from the air inlet 11 at the blade root 5 along the blade height direction. The air first flows along the blade height direction in the air inlet passage 1, and then is deflected and flows through the cooling chamber 2 provided with column ribs 21. The cooling air flows along the blade axial direction in the cooling chamber 2, and finally is discharged through the space between the slit steps 31 of the trailing edge slit 3 to form an air film 32 to protect the blade suction surface. This arrangement structure forms a large vortex 12 in the area of the air inlet passage 1 close to the blade top 4, which restricts the flow of cooling air and makes it impossible to cool the blade top 4 well. Due to the uneven flow distribution of the air inlet passage 1, the outflow of the air film 32 at different blade height positions of the trailing edge slit 3 is also uneven. Among them, the following need to be explained: the blade height direction refers to the direction of the blade along the radial direction of the turbine after the blade is installed on the turbine rotor, and the blade axial direction refers to the direction of the blade along the axial direction of the turbine after the blade is installed on the turbine rotor; the blade root 5 is used to connect with the turbine rotor, and the blade tip 4 is the end of the blade close to the turbine casing.

In the present application, the strip micro-ribs 22 are located in the upstream area of the column ribs 21. When the fluid flows through the strip micro-ribs 22, the near-wall disturbance generated by the strip micro-ribs 22 can strengthen the strength of the horseshoe vortex at the leading edge of the column ribs 21, enhance heat transfer, and improve the heat transfer coefficient of the cooling structure. The cooling structure introduces the strip micro-ribs 22 structure to disturb the near-wall flow, enhance the heat transfer of the column ribs 21, and extend the area of the high heat transfer zone near the column ribs 21. Moreover, the strip-shaped micro-ribs 22 are used to generate flow resistance to the air flow entering the cooling chamber 2, adjust the cold air flow distribution in the blade height direction, improve the uniformity of the cold air flow in the blade height direction, reduce the vortex 12 in the air inlet channel 1 near the blade top 4 area and the separation vortex located at the air inlet 11 near the blade root 5, reduce the low heat exchange area of the original blade top 4 and blade root 5, improve the uniformity of the outflow air film 32 at different blade height positions at the trailing edge split 3, and also reduce the separation caused by uneven upstream flow and the cold flow entering the channel formed by the trailing edge split 3, improve the cooling efficiency of the air film 32 at the trailing edge split 3, and reduce the thermal stress caused by uneven cooling, thereby achieving the purpose of uniform heat exchange on the trailing edge of the blade and extending the service life of the blade.

As shown in FIG. 2 , the length direction of the strip micro-rib 22 is inclined relative to the blade height direction, and the inclination angle α of different strip micro-ribs 22 relative to the blade height direction is the same or different. Different inclination angles α of the strip micro-ribs 22 can make the strip micro-ribs 22 and the flow direction of the airflow flowing through the strip micro-ribs 22 form a certain angle β. When the flow direction of the airflow is perpendicular to the strip micro-ribs 22, the flow resistance is the largest. Compared with the strip micro-ribs 22 being perpendicular to the flow direction of the airflow, when the flow direction forms a certain angle β<90° with the strip micro-rib 22 structure, the flow resistance is reduced. According to the flow characteristics of different positions of the trailing edge of the turbine blade and the flow direction of the fluid, the strip micro-rib 22 structures with different inclination angles α are arranged in different areas, and different flow resistances are generated by the flow direction of the local fluid and the strip micro-rib 22 structure at different angles, so as to achieve the uniform distribution of the flow rate in the trailing edge area of the turbine blade, so as to meet the requirement of uniform distribution of the heat transfer coefficient. In other embodiments, the length direction of the strip micro-ribs 22 can also be parallel to the blade height direction or perpendicular to the blade height direction.

In one embodiment, the cooling chamber 2 is provided with a plurality of column rib rows distributed in sequence along the extension direction from the leading edge to the trailing edge of the blade. Specifically, the cooling chamber 2 is provided with a plurality of column rib groups distributed in sequence along the extension direction from the leading edge to the trailing edge of the blade, each group of the column rib groups includes a first column rib row 23 and a second column rib row 24, the column ribs 21 of each column rib row are distributed in a straight line, the first column rib row 23 and the second column rib row 24 both include a plurality of the column ribs 21 distributed along the height direction of the blade, the column ribs 21 of the first column rib row 23 and the second column rib row 24 are staggered, the column ribs 21 of the same row of all the first column rib rows 23 of different column rib groups are at the same height position of the blade, and the column ribs 21 of the same row of all the second column rib rows 24 of different column rib groups are at the same height position of the blade. In the embodiment of the present application, in the part of the strip micro-rib 22 near the blade top 4 area, in the direction from the leading edge to the trailing edge of the blade, the strip micro-rib 22 gradually inclines from the blade top 4 to the blade root 5 side, that is, the inclination angle α of the strip micro-rib 22 near the blade top 4 area is greater than 90°; in the part of the strip micro-rib 22 near the blade root 5 area, in the direction from the leading edge to the trailing edge of the blade, the strip micro-rib 22 gradually inclines from the blade root 5 to the blade top 4 side, that is, the inclination angle α of the strip micro-rib 22 near the blade root 5 area is less than 90°. In other embodiments, each column rib row may also be distributed in the same manner, so that multiple column ribs 21 are distributed in a matrix; the inclination angle α of the strip micro-ribs 22 may also be changed according to the specific structure of the blade, so that the heat transfer uniformity and heat transfer coefficient of the cooling structure meet the requirements; further in other embodiments, multiple column ribs 21 may also be distributed irregularly, and the strip micro-ribs 22 are arranged in a suitable space according to the distribution of the column ribs 21, so that the strip micro-ribs 22 can play a role in generating flow resistance to the airflow entering the cooling chamber 2, and then the heat exchange requirements are met by adjusting the inclination angle α of the strip micro-ribs 22 relative to the blade height direction.

In one embodiment, the cooling chamber 2 is provided with a plurality of columns of column ribs distributed in sequence along the extension direction from the leading edge to the trailing edge of the blade, and the height of the single column rib 21 of each column rib column on the blade corresponds one to one, and the plurality of column ribs 21 form a matrix distribution of multiple rows and columns, and the column ribs 21 of the same row are at the same height position of the blade, and at least part of the strip micro-ribs 22 correspond to the column ribs 21 of different column rib columns within the extension range, and the turbulence range of an inclined strip micro-rib 22 covers the single column ribs 21 on the column rib columns of different columns, so that a strip micro-rib 22 turbules the upstream side of the column ribs 21 of different columns, and the strip micro-ribs 22 with the same inclination angle can be set to cover all the column ribs 21, and turbulence the airflow on the upstream side of each column rib 21; the strip micro-ribs 22 with multiple inclination angles can also be set, and the number of the strip micro-ribs 22 with each inclination angle can be one or more. In other embodiments, the column ribs 21 of the same row can also be at different height positions of the blade, and the column ribs 21 of the same row can be in a straight line or not in a straight line. It should be explained that the columns of the column ribs 21 are arranged along the height direction of the blade, with the side closest to the air inlet passage 1 being the first row and the side closest to the trailing edge split 3 being the last row, and the definitions of the first row and the last row may also be reversed; the rows of the column ribs 21 are arranged along the axial direction of the blade, with the side closest to the blade root 5 being the first row and the side closest to the blade top 4 being the last row, and the definitions of the first row and the last row may also be reversed.

In one embodiment, the cooling chamber 2 is provided with a plurality of rows of column ribs distributed along the extension direction from the blade tip 4 to the blade root 5, and the column rib rows where the column ribs 21 of different column rib rows are located are different corresponding to the same strip-shaped micro-rib 22. Specifically, the distances from the same strip-shaped micro-rib 22 to column ribs 21 of different columns are the same, that is, when the same strip-shaped micro-rib 22 covers column ribs 21 of different columns and the corresponding column rib rows are different, the corresponding column rib rows are also different. In other embodiments, when the disturbance range of the same strip-shaped micro-rib 22 covers column ribs 21 of different columns, all the corresponding column ribs 21 may also correspond to the same column rib row, that is, when the same strip-shaped micro-rib 22 is located on one side of the same column rib row, and the strip-shaped micro-rib 22 is inclined relative to the blade height direction, the spacings from the strip-shaped micro-rib 22 to different column ribs 21 of the same column rib row are different.

In one embodiment, the strip micro-rib 22 passes through the gap between two adjacent column ribs 21 in the same column rib row, and there is a strip micro-rib 22 between two adjacent column ribs 21 in the same column rib row; so that each column rib 21 corresponds to a strip micro-rib 22.

In one embodiment, the cooling chamber 2 is provided with a plurality of column ribs arranged in sequence along the direction extending from the leading edge to the trailing edge of the blade, and each column rib is provided with the strip micro-ribs 22 on the side facing the leading edge of the blade, and the number of the strip micro-ribs 22 corresponding to each column rib is at least one. The same strip micro-rib 22 is arranged on one side of the same column rib, rather than covering multiple column ribs, and the strip micro-ribs 22 on the upstream side of the same column rib may be a continuous one or multiple strip micro-ribs arranged in sections.

There are multiple strip-shaped micro-ribs 22 corresponding to each column rib row, and the multiple strip-shaped micro-ribs 22 corresponding to each column rib row have the same or different inclination angles relative to the blade height direction.

In one embodiment, the ratio of the height of the strip-shaped micro-ribs 22 protruding from the inner wall surface of the cooling chamber 2 to the height of the column ribs 21 is less than 0.3.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims (10)

1. The utility model provides a turbine movable vane tail edge cooling structure, includes cooling chamber (2) that is located turbine movable vane tail edge inside, be equipped with a plurality of column ribs (21) in cooling chamber (2), one side of cooling chamber (2) is equipped with inlet channel (1), inlet channel (1) and air inlet (11) of blade root (5) communicate, the opposite side of cooling chamber (2) is equipped with tail edge split joint (3), characterized in that, be equipped with a plurality of strip micro-rib (22) on the interior wall of the pressure face and/or the suction face of corresponding blade in cooling chamber (2), strip micro-rib (22) outstanding cooling chamber (2) interior wall, strip micro-rib (22) pass the space region between column rib (21), strip micro-rib (22) are located the one side of column rib (21) back to blade tail edge;

The cooling air enters the air inlet channel (1) from the air inlet (11) along the height direction of the blade, and flows out of the tail edge split joint (3) after passing through the strip-shaped micro ribs (22) and the column ribs (21) in the cooling cavity (2), wherein the strip-shaped micro ribs (22) are used for generating flow resistance to the air flow entering the cooling cavity (2), and the swirl vortex (12) of the air inlet channel (1) close to the blade tip (4) area is reduced.

2. The turbine blade trailing edge cooling structure according to claim 1, wherein the lengthwise direction of the strip-shaped micro ribs (22) is inclined with respect to the blade height direction, and the inclination angles of the strip-shaped micro ribs (22) with respect to the blade height direction are the same or different.

3. The turbine blade trailing edge cooling structure according to claim 2, wherein the strip-like micro ribs (22) are gradually inclined from the blade tip (4) of the blade to the blade root (5) side of the blade in a direction from the leading edge to the trailing edge of the blade at a portion near the blade tip (4) region of the blade;

The strip-shaped micro ribs (22) in the area close to the blade root (5) gradually incline from the blade root (5) to the blade top (4) side of the blade in the direction from the front edge to the tail edge of the blade.

4. The turbine blade trailing edge cooling structure according to claim 2, wherein a plurality of column rib rows are provided in the cooling chamber (2) and are sequentially distributed along the extending direction from the leading edge to the trailing edge of the blade, and at least part of the strip-shaped micro ribs (22) correspond to the column ribs (21) of different column rib rows in the extending range.

5. The turbine blade trailing edge cooling structure according to claim 4, wherein a plurality of rows of column rib rows distributed along the extending direction from the blade tip (4) to the blade root (5) are provided in the cooling chamber (2), the column rib rows where the column ribs (21) of the same strip-shaped micro rib (22) are located are different, and the column rib rows where the column ribs (21) of the different column rib rows are located are sequentially changed along the extending direction of the strip-shaped micro rib (22).

6. The turbine bucket trailing edge cooling structure according to claim 4, wherein the strip-shaped micro ribs (22) pass through a gap between two adjacent ones of the column ribs (21) in the same column rib row, and the strip-shaped micro ribs (22) are provided between two adjacent column ribs (21) in the same column rib row.

7. The turbine blade trailing edge cooling structure according to claim 2, wherein a plurality of column rib rows are sequentially distributed along the extending direction from the front edge to the tail edge of the blade in the cooling chamber (2), the strip-shaped micro ribs (22) are arranged on one side of each column rib row facing the front edge of the blade, and the number of the strip-shaped micro ribs (22) corresponding to each column rib row is at least one.

8. The turbine bucket trailing edge cooling structure according to claim 7, wherein the number of the strip-like micro ribs (22) corresponding to each column rib row is plural, and the inclination angles of the plurality of strip-like micro ribs (22) corresponding to each column rib row with respect to the bucket height direction are the same or different.

9. The turbine bucket trailing edge cooling structure according to any one of claims 2 to 8, wherein a plurality of column rib groups are provided in the cooling chamber (2) and are sequentially distributed along the direction of extension of the bucket leading edge to the trailing edge, each of the column rib groups includes a first column rib row (23) and a second column rib row (24), each of the first column rib row (23) and the second column rib row (24) includes a plurality of column ribs (21) distributed along the bucket height direction, the column ribs (21) of the first column rib row (23) and the second column rib row (24) are staggered, the column ribs (21) of the same row of all the first column rib rows (23) of different column rib groups are at the same height position of the bucket, and the column ribs (21) of the same row of all the column rib rows (24) of different column rib groups are at the same height position of the bucket.

10. The turbine bucket trailing edge cooling structure according to claim 1, wherein a ratio of a height of the strip-shaped micro-ribs (22) protruding from the inner wall surface of the cooling chamber (2) to a height of the column ribs (21) is less than 0.3.