Air film cooling guide vane structure

Abstract

The invention provides an air film cooling guide vane structure, which belongs to the technical field of turbine blades of gas turbines and comprises a guide vane body, an air supply cavity is arranged in the guide vane body, multiple rows of suction surface air film holes are formed in the suction surface of the guide vane body and close to the front edge, multiple rows of front edge air film holes are formed in the front edge, and multiple rows of pressure surface air film holes are formed in the pressure surface. The tail edge is provided with a tail edge crack, and the air film holes and the tail edge crack are respectively communicated with the air supply cavity; the suction surface air film holes are elliptical holes inclining in the axial direction of the guide vane body, the front edge air film holes are cylindrical holes inclining in the radial direction of the guide vane body, and the row of pressure surface air film holes close to the front edge are elliptical holes inclining in the radial direction and the axial direction of the guide vane body. The rest pressure surface film holes are elliptical holes which are inclined along the axial direction of the guide vane body; and the long axis of each elliptical hole is parallel to the radial direction of the guide vane body. According to the scheme, the failure risk of the air film hole is reduced, the cooling efficiency is improved, and the service life of the blade is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of gas turbine turbine blades, and in particular to a film cooling guide vane structure. Background Art

[0002] The turbine blades of gas turbines are subject to very high heat loads, and blade cooling technology is required to cool the base metal material of the blades. Film cooling is a key external cooling technology, and cylindrical film holes are the conventional film holes. For turbine guide vanes, the upper and lower end walls are fixed between the inner edge ring and the outer edge ring. The inner edge ring and the outer edge ring cannot be greatly deformed due to axial mutual constraints. Therefore, the thermal expansion of the blades is limited along the blade height direction, which causes the turbine guide vanes to be subjected to compressive stress during operation. The axially inclined cylindrical film holes will cause greater stress concentration, generate greater thermal stress at the sharp edges of the holes, and increase the failure risk of the film cooling holes. Therefore, it is necessary to reduce the stress concentration of the film holes and increase the service life of the film cooling holes and turbine guide vanes. Summary of the invention

[0003] In view of this, an embodiment of the present application provides a film cooling guide vane structure, which at least partially solves the problem of stress concentration around the cylindrical film holes on the film cooling turbine guide vane in the prior art.

[0004] An embodiment of the present application provides an air film cooling guide vane structure, wherein the air film cooling guide vane structure comprises a guide vane body, an air supply cavity is arranged inside the guide vane body, a plurality of rows of suction surface air film holes are arranged on the suction surface of the guide vane body and near the leading edge, a plurality of rows of leading edge air film holes are arranged on the leading edge of the guide vane body, a plurality of rows of pressure surface air film holes are arranged on the pressure surface of the guide vane body, a trailing edge slit is arranged on the trailing edge of the guide vane body, the suction surface air film holes, the leading edge air film holes, the pressure surface air film holes and the trailing edge slit are respectively connected with the air supply cavity; the suction surface air film holes are arranged as elliptical holes inclined along the axial direction of the guide vane body, the leading edge air film holes are arranged as cylindrical holes inclined along the radial direction of the guide vane body, a row of pressure surface air film holes close to the leading edge of the plurality of rows of pressure surface air film holes is arranged as elliptical holes inclined along both the radial direction and the axial direction of the guide vane body, the remaining pressure surface air film holes of the plurality of rows of pressure surface air film holes are arranged as elliptical holes inclined along the axial direction of the guide vane body, and the major axis of each elliptical hole is parallel to the radial direction of the guide vane body.

[0005] According to a specific implementation method of an embodiment of the present application, the air supply cavity includes a first air supply cavity and a second air supply cavity, the first air supply cavity is close to the leading edge of the guide vane body, and the second air supply cavity is close to the trailing edge of the guide vane body. The pressure surface air film holes, suction surface air film holes and leading edge air film holes in the multiple rows of pressure surface air film holes that are inclined along the radial and axial directions of the guide vane body are respectively connected to the first air supply cavity, and the remaining pressure surface air film holes and trailing edge slits in the multiple rows of pressure surface air film holes are respectively connected to the second air supply cavity.

[0006] According to a specific implementation method of an embodiment of the present application, the angle formed by the axis of the suction surface air film hole and the axial tangent of the blade surface where the air film hole is located is in the range of 30°-60°, and the major axis radius of the suction surface air film hole is 3-4 times the minor axis radius.

[0007] According to a specific implementation of the embodiment of the present application, the angle formed by the axis of the leading edge air film hole and the radial direction of the guide vane body is in the range of 25°-45°.

[0008] According to a specific implementation method of an embodiment of the present application, the pressure surface air film holes are arranged in three rows, namely, the first pressure surface air film holes, the second pressure surface air film holes and the third pressure surface air film holes. The first pressure surface air film holes are a row of pressure surface air film holes close to the leading edge, the third pressure surface air film holes are close to the trailing edge, and the second pressure surface air film holes are arranged between the first pressure surface air film holes and the third pressure surface air film holes. The inclination angle of each row of pressure surface air film holes is different.

[0009] According to a specific implementation method of an embodiment of the present application, the angle formed by the axis of the first air film hole on the pressure surface and the tangent of the blade profile arc where the air film hole is located is in the range of 35°-60°, the angle formed by the axis of the first air film hole on the pressure surface and the radial direction of the guide vane body is in the range of 45°-70°, and the major axis radius of the first air film hole on the pressure surface is 3-4 times the minor axis radius.

[0010] According to a specific implementation method of an embodiment of the present application, the angle formed by the axis of the second air film hole on the pressure surface and the tangent of the blade profile arc where the air film hole is located is in the range of 25°-45°, and the major axis radius of the second air film hole on the pressure surface is 3-4 times the minor axis radius.

[0011] According to a specific implementation method of an embodiment of the present application, the angle formed by the axis of the third air film hole on the pressure surface and the tangent of the blade profile arc where the air film hole is located is in the range of 20°-60°, and the major axis radius of the third air film hole on the pressure surface is 3-4 times the minor axis radius.

[0012] According to a specific implementation of the embodiment of the present application, the trailing edge slit is set as a rectangular slit.

[0013] According to a specific implementation of an embodiment of the present application, the leading edge air film holes are arranged in seven rows, and the suction surface air film holes are arranged in two rows.

[0014] Beneficial effects:

[0015] The film cooling guide vane structure in the embodiment of the present application arranges elliptical film holes on the pressure side and suction side of the turbine guide vane so that the film holes present an ellipse with the long axis parallel to the main stress direction on the trajectory of the compressive stress, thereby achieving the purpose of reducing the stress concentration coefficient around the film holes, thereby effectively reducing thermal stress concentration, reducing the failure risk of the film holes, improving the overall cooling efficiency, and extending the service life of the blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1 Schematic diagram of a film cooling guide vane structure according to an embodiment of the present invention, FIG. (a) is a left view of the guide vane corresponding to FIG. (b), FIG. (b) is a cross-sectional schematic diagram of the guide vane, and FIG. (c) is a right view of the guide vane corresponding to FIG. (b);

[0018] Figure 2 is a three-dimensional diagram of a film cooling guide vane structure according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of the inclination angle of the air film hole according to an embodiment of the present invention;

[0020] Figure 4 Figure 1 is a temperature distribution cloud diagram of a film cooling guide vane structure according to an embodiment of the present invention, Figure (a) is a conventional cooling blade using cylindrical film holes, and Figure (b) is a cooling blade using elliptical film holes;

[0021] Figure 5 Figure 1 is a cloud diagram of the equivalent stress distribution on the suction surface of a film cooling guide vane structure according to an embodiment of the present invention, wherein Figure (a) is a conventional cooling blade using cylindrical film holes, and Figure (b) is a cooling blade using elliptical film holes;

[0022] Figure 6 1 is a cloud diagram of equivalent stress distribution on the pressure surface of a film cooling guide vane structure according to an embodiment of the present invention, wherein (a) is a conventional cooling blade using cylindrical film holes, and (b) is a cooling blade using elliptical film holes.

[0023] In the figure: 1. The first air film hole on the suction side; 2. The second air film hole on the suction side; 3. The first air film hole on the leading edge; 4. The second air film hole on the leading edge; 5. The third air film hole on the leading edge; 6. The fourth air film hole on the leading edge; 7. The fifth air film hole on the leading edge; 8. The sixth air film hole on the leading edge; 9. The seventh air film hole on the leading edge; 10. The first air film hole on the pressure side; 11. The second air film hole on the pressure side; 12. The third air film hole on the pressure side; 13. The trailing edge slit; 14. The second air supply cavity; 15. The first air supply cavity; 30. The suction side; 40. The pressure side. DETAILED DESCRIPTION

[0024] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0025] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents 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.

[0026] 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.

[0027] 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 at will, and the component layout may also be more complicated.

[0028] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0029] The present application embodiment provides a film cooling guide vane structure. Figures 1 to 5 Describe in detail.

[0030] In one embodiment, referring to Figure 1 and Figure 2 The film cooling guide vane structure includes a guide vane body, an air supply cavity is arranged inside the guide vane body, a plurality of rows of suction surface film holes are arranged on the suction surface 30 of the guide vane body and near the leading edge, a plurality of rows of leading edge film holes are arranged on the leading edge of the guide vane body, a plurality of rows of pressure surface film holes are arranged on the pressure surface 40 of the guide vane body, a trailing edge slit is arranged on the trailing edge of the guide vane body, the suction surface film holes, the leading edge film holes, the pressure surface film holes and the trailing edge slit are respectively connected with the air supply cavity; the suction surface film holes are arranged as elliptical holes inclined along the axial direction of the guide vane body, the leading edge film holes are arranged as cylindrical holes inclined along the radial direction of the guide vane body, the flow cross-sections of the leading edge film holes are also elliptical, a row of pressure surface film holes close to the leading edge of the plurality of rows of pressure surface film holes is arranged as elliptical holes inclined along both the radial direction and the axial direction of the guide vane body, the remaining pressure surface film holes in the plurality of rows of pressure surface film holes are arranged as elliptical holes inclined along the axial direction of the guide vane body, and the major axis of each elliptical hole is parallel to the radial direction of the guide vane body.

[0031] In this embodiment, elliptical film holes are added to the pressure surface 40 and the suction surface 30 of the turbine guide vane structure, and the major axis of the elliptical hole is parallel to the radial direction of the guide vane body. Since the upper and lower end walls of the turbine guide vane are constrained in the radial direction and cannot expand freely, the blade body film holes are subjected to compressive stress during the restricted thermal expansion process. The low-stress and long-life film-cooled turbine guide vane design of this embodiment is characterized in that the film holes present an ellipse with a major axis parallel to the main stress direction on the trajectory of the compressive stress, thereby achieving the purpose of reducing the stress concentration coefficient around the hole, and achieving the effect of low stress and long life. Therefore, the film-cooled guide vane structure in this embodiment improves the comprehensive cooling efficiency of the blade, reduces the peak thermal stress around the film hole, reduces the failure risk of the film hole, and increases the service life of the blade.

[0032] In specific implementation, the air film holes arranged along the radial direction of the turbine guide vane are exhaust film holes, and the number of each exhaust film hole is reasonably set according to the size of the single air film hole and the required performance. Preferably, each exhaust film hole is evenly arranged, that is, each row of air film holes is arranged at equal intervals.

[0033] Furthermore, the air supply cavity includes a first air supply cavity 15 and a second air supply cavity 14. The first air supply cavity 15 is close to the leading edge of the guide vane body, and the second air supply cavity 14 is close to the trailing edge of the guide vane body. The pressure surface air film holes, suction surface air film holes and leading edge air film holes in the multiple rows of pressure surface air film holes that are inclined along the radial and axial directions of the guide vane body are respectively connected to the first air supply cavity 15, and the remaining pressure surface air film holes and trailing edge slits in the multiple rows of pressure surface air film holes are respectively connected to the second air supply cavity 14.

[0034] In the specific implementation, in order to indicate the inclination direction of the air film hole, refer to Figure 3 As shown in the figure, the angle of the film hole can be divided into an inclination angle α and a compound angle β. The Z axis is the blade height direction, the S axis is the blade surface flow direction, and the H axis is the blade thickness direction. The inclination angle refers to the angle between the axis of the film hole and the blade surface, that is, Figure 3 As shown in α, the compound angle refers to the angle between the axis of the air film hole and the blade height direction Z, that is, Figure 3 As shown in β.

[0035] In one embodiment, the angle formed by the axis of the air film hole on the suction surface and the axial tangent of the blade surface where the air film hole is located is in the range of 30°-60°, and the major axis radius of the air film hole on the suction surface is 3-4 times the minor axis radius, that is, the α angle of the air film hole on the suction surface is in the range of 30°-60°, the β angle is 90°, and the major axis of the air film hole on the suction surface is along the Z direction.

[0036] Reference Figure 1 and Figure 2 The air film holes on the suction surface can be arranged in two rows, including the first air film holes 1 on the suction surface and the second air film holes 2 on the suction surface. The air film holes on the suction surface are arranged close to the leading edge air film holes. The air film holes on the suction surface are arranged in an elliptical structure, and the long axis thereof is parallel to the radial direction of the guide vane body. The air film holes are on the trajectory of the compressive stress, and the long axis is parallel to the main stress direction, so as to achieve the purpose of reducing the stress concentration coefficient around the air film holes, reducing the peak thermal stress around the air film holes, and thus reducing the risk of failure of the air film holes.

[0037] Preferably, the angle α formed by the axis of the air film hole on the suction surface and the axial tangent of the blade surface where the air film hole is located is 30°, and the major axis radius of the air film hole on the suction surface is 3 times the minor axis radius.

[0038] In one embodiment, the angle formed by the axis of the leading edge air film hole and the radial direction of the guide vane body is in the range of 25°-45°, that is, the angle α is in the range of 25°-45°, and the angle β is 0°.

[0039] Preferably, the leading edge air film holes are arranged in seven rows, and the angle α formed by the axis of the leading edge air film holes and the radial direction of the guide vane body is 25°, and the leading edge air film holes include a leading edge first air film hole 3, a leading edge second air film hole 4, a leading edge third air film hole 5, a leading edge fourth air film hole 6, a leading edge fifth air film hole 7, a leading edge sixth air film hole 8, and a leading edge seventh air film hole 9 which are arranged in sequence.

[0040] In one embodiment, the pressure surface air film holes are arranged in three rows, namely, first pressure surface air film holes 10, second pressure surface air film holes 11 and third pressure surface air film holes 12. The first pressure surface air film holes 10 are a row of pressure surface air film holes close to the leading edge, the third pressure surface air film holes 12 are close to the trailing edge, the second pressure surface air film holes 11 are arranged between the first pressure surface air film holes 10 and the third pressure surface air film holes 12, and the inclination angle of each row of pressure surface air film holes is different.

[0041] In one embodiment, the angle formed by the axis of the first air film hole 10 on the pressure surface and the tangent of the blade profile arc at the position of the air film hole is in the range of 35°-60°, the angle formed by the axis of the first air film hole 10 on the pressure surface and the radial direction of the guide vane body is in the range of 45°-70°, the major axis radius of the first air film hole 10 on the pressure surface is 3-4 times the minor axis radius, that is, the α angle of the first air film hole 10 on the pressure surface is in the range of 35°-60°, the β angle is in the range of 45°-70°, and the major axis of the first air film hole 10 on the pressure surface is along the Z direction.

[0042] Preferably, the angle α formed by the axis of the first air film hole 10 on the pressure surface and the tangent of the blade profile arc where the air film hole is located is 35°, the angle β formed by the axis of the first air film hole 10 on the pressure surface and the radial direction of the guide vane body is 60°, and the major axis radius of the first air film hole 10 on the pressure surface is 3 times the minor axis radius.

[0043] In one embodiment, the angle formed by the axis of the second air film hole 11 on the pressure surface and the tangent of the blade profile arc at the position of the air film hole is in the range of 25°-45°, and the major axis radius of the second air film hole 11 on the pressure surface is 3-4 times the minor axis radius, that is, the α angle of the second air film hole 11 on the pressure surface is in the range of 25°-45°, the β angle is 90°, and the major axis of the second air film hole 11 on the pressure surface is along the Z direction.

[0044] Preferably, the angle α formed by the axis of the second air film hole 11 on the pressure surface and the tangent of the blade profile arc where the air film hole is located is 25°, and the major axis radius of the second air film hole 11 on the pressure surface is 4 times the minor axis radius.

[0045] In one embodiment, the angle formed by the axis of the third air film hole 12 on the pressure surface and the tangent of the blade profile arc where the air film hole is located is in the range of 20°-60°, the major axis radius of the third air film hole 12 on the pressure surface is 3-4 times the minor axis radius, the α angle of the third air film hole 12 on the pressure surface is in the range of 20°-60°, and its β angle is 90°, and the major axis of the third air film hole 12 on the pressure surface is along the Z direction.

[0046] Preferably, the angle α formed by the axis of the third air film hole 12 on the pressure surface and the tangent of the blade profile arc at the location of the air film hole is 22°, and the major axis radius of the third air film hole 12 on the pressure surface is 3.4 times the minor axis radius.

[0047] In one embodiment, the trailing edge slit 13 is configured as a rectangular slit.

[0048] Regarding the number and inclination of the film holes, since the film holes on the suction side are generally arranged before the throat section and the film jet on the suction side has a better wall attachment effect, the number of film holes on the suction side is relatively small and only needs to be tilted along the flow direction. The heat load on the leading edge of the blade is the highest, so the number of film holes is relatively large, and since the curvature of the leading edge of the blade is large, it is impossible to arrange the film holes tilted along the flow direction. In order to ensure the wall attachment effect of the film jet, the α angle is made smaller on the basis of the β angle of 0°. The length before the throat of the pressure side is relatively long, and the pressure changes along the way are relatively large, so it is necessary to arrange more rows of film holes.

[0049] Preferably, the leading edge air film holes are arranged in seven rows, the suction surface air film holes are arranged in two rows, and the pressure surface air film holes are arranged in three rows.

[0050] It should be noted that the selection of the inclination angle of the above-mentioned elliptical film hole should be optimized within a given range according to the geometric limitations of the location of the film hole. Generally speaking, the smaller the angle formed between the film hole and the local blade surface, the better the film cooling effect. The selection of the inclination angle of the above-mentioned elliptical film hole should be optimized within a given range according to the geometric limitations of the location of the film hole. Generally speaking, the smaller the angle formed between the film hole and the local blade surface, the better the film cooling effect.

[0051] In one embodiment, the turbine guide vane structure in the above embodiment is used for test simulation, the total temperature of the inlet gas of the mainstream channel is 709K, the total pressure of the inlet gas of the mainstream channel is 344.750 kPa, the static pressure of the outlet of the mainstream channel is 206.431 kPa, and the pressure drop ratio is about 1.67.

[0052] In this embodiment, cold air is supplied to the front and rear cavities, the total supply pressure is 350.950 kPa, the ratio of cold air supply to mainstream stagnation pressure is about 1.017, and the total temperature of cold air supply is 339K.

[0053] In this embodiment, a conventional cooling blade with a cylindrical air film hole and a cooling blade with an elliptical air film hole described in the embodiment of the present application are used for comparison and verification. The air film hole flow area of ​​the cooling blade with a cylindrical air film hole is consistent with the air film hole flow area of ​​the cooling blade with an elliptical air film hole described in the embodiment of the present application, and the boundary conditions of the two are also consistent.

[0054] The results show that the cooling air mass flow rate of the cooling blade using the cylindrical air film hole is about 0.0195 kg / s, and the cooling air mass flow rate of the cooling blade using the elliptical air film hole described in the embodiment of the present application is about 0.01896 kg / s, with a relative error of about 2.7%, which shows that the flow capacity of the two is the same.

[0055] The average surface temperature of the cooling blade using the cylindrical air film hole is 435.64K, and the average comprehensive cooling efficiency is about 0.74. The average surface temperature of the cooling blade using the elliptical air film hole described in the embodiment of the present application is 425.37K, and the average comprehensive cooling efficiency is about 0.77. The comparison of the temperature distribution on the blade surface is as follows: Figure 4 As shown, the turbine guide vane structure of the present application improves the average comprehensive cooling efficiency by 4% while using a relatively small amount of cooling air, and reduces the average temperature of the blade surface by about 10K. This shows that the cooling blade with the elliptical air film hole designed in the present application has better cooling performance.

[0056] In addition, the present application adopts cooling blades with elliptical air film holes, which almost eliminates the stress concentration caused by the air film holes and greatly reduces the failure risk of the air film holes. Figure 5 The Mises stress distribution on the suction surface was compared. Figure 6 The Mi ses stress distribution on the pressure surface is compared. Figure 5 and Figure 6 It can be found that for cooling blades using conventional cylindrical air film holes, there are stress concentration areas around the air film holes, and the maximum Mi ses stress around the pressure surface air film holes can reach about 1900 MPa. However, for cooling blades using the elliptical air film holes designed in the present application, there is no obvious stress concentration around the air film holes, and the maximum Mi ses stress around the pressure surface air film holes is reduced to about 1200 MPa.

[0057] Therefore, the film-cooled turbine guide vane structure in the present application, by arranging elliptical film holes on the pressure side and the suction side, setting the inclination direction of the film holes, and making the major axis direction of the elliptical film holes parallel to the radial direction of the guide vane, can make the film holes present an ellipse with the major axis parallel to the principal stress direction on the trajectory of the compressive stress, thereby reducing the stress concentration coefficient around the hole, reducing the peak thermal stress around the film hole, reducing the failure risk of the film hole, and improving the comprehensive cooling efficiency of the blade, thereby increasing the service life of the blade.

[0058] 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

1. A film cooling guide vane structure, characterized in that: The air film cooling guide vane structure comprises a guide vane body, an air supply cavity is arranged inside the guide vane body, a plurality of rows of suction surface air film holes are arranged on the suction surface (30) of the guide vane body and near the leading edge, a plurality of rows of leading edge air film holes are arranged on the leading edge of the guide vane body, a plurality of rows of pressure surface air film holes are arranged on the pressure surface (40) of the guide vane body, a trailing edge slit (13) is arranged on the trailing edge of the guide vane body, the suction surface air film holes, the leading edge air film holes, the pressure surface air film holes and the trailing edge slit (13) are respectively connected to the air supply cavity; the suction surface air film holes are arranged as elliptical holes inclined along the axial direction of the guide vane body, the leading edge air film holes are arranged as cylindrical holes inclined along the radial direction of the guide vane body, a row of pressure surface air film holes near the leading edge of the plurality of pressure surface air film holes is arranged as elliptical holes inclined along both the radial direction and the axial direction of the guide vane body, the remaining pressure surface air film holes of the plurality of pressure surface air film holes are arranged as elliptical holes inclined along the axial direction of the guide vane body, and the major axis of each elliptical hole is parallel to the radial direction of the guide vane body.

2. The film cooling guide vane structure according to claim 1, characterized in that: The air supply cavity comprises a first air supply cavity (15) and a second air supply cavity (14), wherein the first air supply cavity (15) is close to the leading edge of the guide vane body, and the second air supply cavity (14) is close to the trailing edge of the guide vane body. The pressure surface air film holes, the suction surface air film holes and the leading edge air film holes in the multiple rows of pressure surface air film holes, which are inclined along the radial direction and the axial direction of the guide vane body, are respectively connected to the first air supply cavity (15), and the remaining pressure surface air film holes and the trailing edge slits (13) in the multiple rows of pressure surface air film holes are respectively connected to the second air supply cavity (14).

3. The film cooling guide vane structure according to claim 1, characterized in that: The angle formed by the axis of the air film hole on the suction surface and the axial tangent of the blade surface where the air film hole is located ranges from 30° to 60°, and the major axis radius of the air film hole on the suction surface is 3-4 times the minor axis radius.

4. The film cooling guide vane structure according to claim 1, characterized in that: The angle formed by the axis of the leading edge air film hole and the radial direction of the guide vane body is in the range of 25°-45°.

5. The film cooling guide vane structure according to claim 1, characterized in that: The pressure surface air film holes are arranged in three rows, namely, the first pressure surface air film holes (10), the second pressure surface air film holes (11) and the third pressure surface air film holes (12). The first pressure surface air film holes (10) are a row of pressure surface air film holes close to the leading edge, the third pressure surface air film holes (12) are close to the trailing edge, the second pressure surface air film holes (11) are arranged between the first pressure surface air film holes (10) and the third pressure surface air film holes (12), and the inclination angle of each row of pressure surface air film holes is different.

6. The film cooling guide vane structure according to claim 5, characterized in that: The angle formed by the axis of the first air film hole (10) on the pressure surface and the tangent of the blade profile arc at the location of the air film hole is in the range of 35°-60°, the angle formed by the axis of the first air film hole (10) on the pressure surface and the radial direction of the guide vane body is in the range of 45°-70°, and the major axis radius of the first air film hole (10) on the pressure surface is 3-4 times the minor axis radius.

7. The film cooling guide vane structure according to claim 5, characterized in that: The angle formed by the axis of the second air film hole (11) on the pressure surface and the tangent of the blade profile arc where the air film hole is located is in the range of 25°-45°, and the major axis radius of the second air film hole (11) on the pressure surface is 3-4 times the minor axis radius.

8. The film cooling guide vane structure according to claim 5, characterized in that: The angle formed by the axis of the third air film hole (12) on the pressure surface and the tangent of the blade profile arc at the location of the air film hole is in the range of 20°-60°, and the major axis radius of the third air film hole (12) on the pressure surface is 3-4 times the minor axis radius.

9. The film cooling guide vane structure according to any one of claims 1 to 8, characterized in that: The trailing edge split seam (13) is arranged as a rectangular split seam.

10. The film cooling guide vane structure according to any one of claims 1 to 8, characterized in that: The leading edge air film holes are arranged in seven rows, and the suction surface air film holes are arranged in two rows.

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