A turbine blade and double wall thereof

Abstract

A turbine blade and a double wall thereof, the double wall comprising: an inner solid wall provided with a plurality of impact holes, an outer solid wall and a microstructure unit; wherein a gap is provided between the outer solid wall and the inner solid wall, and the microstructure unit is provided on the surface of the outer solid wall facing the inner solid wall so that the side of the outer solid wall facing the inner solid wall is uneven. The double wall has high heat exchange efficiency and is light in weight.

Description

Technical Field

[0001] The present invention relates to a cooling technology for an aircraft engine and a gas turbine, and in particular to a turbine blade and a double-layer wall thereof. Background Art

[0002] Increasing the turbine inlet temperature of aircraft engines and gas turbines is an important way to achieve higher cycle efficiency and ultra-low pollution emissions. The operating temperature of high-temperature components of contemporary advanced aircraft engines has reached over 2000K, far exceeding the temperature limit of metal tolerance. Higher temperatures and limited cooling air volume pose great challenges to the cooling of high-temperature components, and more efficient cooling technology is needed to break through the limits of traditional cooling technology.

[0003] Double-wall is a cooling structure with great potential. The structure uses the inner and outer walls and their interlayers as the main heat exchange structure. Usually, the cooling gas passes through the inner wall through the impact hole, exchanges heat in the interlayer, and then flows out from the air film holes or the side of the outer wall. In order to further improve the cooling efficiency of the double-wall, a considerable number of column rib structures will be arranged in the interlayer to enhance heat exchange.

[0004] This type of double-wall structure has three problems: first, the column-rib structure will lead to a significant increase in flow resistance; second, the column-rib structure will increase the weight of the cooling structure, which is not conducive to improving the engine thrust-to-weight ratio; third, the column-rib structure can increase the heat exchange area, but the heat transfer efficiency of the surface far from the hot end is relatively low. Summary of the invention

[0005] A technical problem to be solved by the present invention is how to increase the heat exchange efficiency of the double wall.

[0006] In order to solve the above technical problems, the present application provides a double-layer wall, which includes: an inner solid wall provided with a plurality of impact holes, an outer solid wall and a microstructure unit;

[0007] There is a gap between the outer solid wall and the inner solid wall, and the microstructure unit is arranged on the surface of the outer solid wall facing the inner solid wall so that the surface of the outer solid wall facing the inner solid wall is uneven.

[0008] The coolant enters the gap between the outer solid wall and the inner solid wall through the impact hole. After passing through the impact hole, the coolant forms an injection flow and is ejected onto the surface of the outer solid wall facing the inner solid wall for heat exchange. Finally, the coolant flows out from the end of the double wall along the gap.

[0009] The surface of the outer solid wall facing the inner solid wall is provided with microstructure units, making the surface uneven. The microstructure units can disturb the coolant, enhancing the turbulent flow transport capacity of the surface. At the same time, the microstructure units also increase the heat exchange area with the coolant, thereby improving the heat exchange efficiency. At the same time, due to the small size of the microstructure units, the disturbance to the large-scale flow of the coolant is small, which can effectively reduce the flow resistance of the coolant. In addition, the microstructure units are used to replace most of the column rib structures in the prior art to improve heat exchange, thereby significantly reducing the number of column rib structures, so as to reduce the total weight of the turbine blades and increase the engine thrust-to-weight ratio.

[0010] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0012] Figure 1 is a schematic diagram of a cross section of a turbine blade in an embodiment of the present application;

[0013] Figure 2 This is a three-dimensional schematic diagram of a double-layer wall in an embodiment of the present application;

[0014] Figure 3 This is a schematic front view of a double-layer wall in an embodiment of the present application;

[0015] Figure 4 for Figure 3 Schematic cross-sectional view of the AA plane;

[0016] Figure 5 This is a schematic front view of a double-layer wall in an embodiment of the present application;

[0017] Figure 6 for Figure 5 Schematic cross-sectional view of the middle BB surface;

[0018] Figure 7 This is a schematic front view of a double-layer wall in an embodiment of the present application;

[0019] Figure 8 for Figure 7 Schematic cross-sectional view of the middle CC plane;

[0020] Fig. 9 This is a schematic front view of a double-layer wall in an embodiment of the present application;

[0021] Fig.10 for Fig. 9 Schematic cross-sectional view of the middle DD surface. DETAILED DESCRIPTION

[0022] like Figure 1 As shown, Figure 1 The structure of a turbine blade is shown. This turbine blade can be used in aircraft engines and gas turbines. The turbine blade includes a double wall 1. The double wall 1 encloses a main structure of the turbine blade. The main structure of the turbine blade has a coolant supply cavity 2 inside. The coolant supply cavity 2 is connected to a coolant supply device (not shown in the figure), and the coolant supply device can inject coolant into the coolant supply cavity 2. The coolant is a cryogenic fluid, which can be a gas or a liquid.

[0023] like Figure 1 , 2 As shown, the double-layer wall 1 includes an inner solid wall 11, an outer solid wall 12 and a microstructure unit 13. The inner solid wall 11 and the outer solid wall 12 are both plate-shaped. The inner solid wall 11 is arranged on the inner side of the outer solid wall 12. There is a gap between the inner solid wall 11 and the outer solid wall 12. The coolant supply chamber 2 is arranged on the inner side of the inner solid wall 11. A plurality of impact holes 111 are arranged on the inner solid wall 11. The plurality of impact holes 111 can be arranged in an array on the inner solid wall 11. The impact holes 111 vertically penetrate the inner solid wall 11. Each impact hole 111 is connected to the coolant supply chamber 2. The impact hole 111 is preferably a circular hole.

[0024] like Figure 3 As shown, the microstructure unit 13 is arranged on the surface of the outer solid wall 12 facing the inner solid wall 11. In this embodiment, the microstructure unit 13 includes a plurality of protrusions 13a. The plurality of protrusions 13a are distributed on the surface of the outer solid wall 12 facing the inner solid wall 11. The plurality of protrusions 13a can be arranged in an array on the outer solid wall 12. The protrusions 13a protrude from the outer solid wall 12 toward the direction close to the inner solid wall 11. These protrusions 13a make the side of the outer solid wall 12 facing the inner solid wall 11 uneven.

[0025] When in use, the coolant in the coolant supply cavity enters the gap between the outer solid wall 12 and the inner solid wall 11 through the impact hole 111. After passing through the impact hole 111, the coolant forms an injection flow and is ejected onto the surface of the outer solid wall 12 facing the inner solid wall 11 for heat exchange. Finally, the coolant flows out from the end of the double wall 1 along the gap.

[0026] The surface of the outer solid wall 12 facing the inner solid wall 11 is provided with a microstructure unit 13, making the surface uneven. The microstructure unit 13 can disturb the coolant, thereby enhancing the turbulent flow transport capacity of the surface. At the same time, the microstructure unit 13 also increases the heat exchange area with the coolant, thereby improving the heat exchange efficiency. At the same time, due to the small size of the microstructure unit 13, the disturbance to the large-scale flow of the coolant is small, which can effectively reduce the flow resistance of the control coolant. In addition, the microstructure unit 13 is used to replace most of the column rib structures in the prior art to improve heat exchange, thereby significantly reducing the number of column rib structures, so as to reduce the total weight of the turbine blades and increase the engine thrust-to-weight ratio.

[0027] In an exemplary embodiment, the height of the protrusion 13 a is less than one tenth of the distance between the outer solid wall 12 and the inner solid wall 11 .

[0028] When the height of the protrusion 13a is less than one tenth of the distance between the outer solid wall 12 and the inner solid wall 11, the resistance to the flow of the coolant can be significantly reduced, and even has a drag reduction effect.

[0029] In an exemplary embodiment, the number of the protrusions 13a is greater than the number of the impact holes 111. A plurality of protrusions 13a are correspondingly arranged below each impact hole 111. The airflow injected from each impact hole 111 toward the protrusion 13a can be diffused to the plurality of protrusions 13a, thereby further improving the heat exchange efficiency.

[0030] In an exemplary embodiment, the double-layer wall 1 further includes a connecting column 14 disposed between the outer solid wall 12 and the inner solid wall 11. One end of the connecting column 14 is connected to the outer solid wall 12, and the other end of the connecting column 14 is connected to the inner solid wall 11. The connecting column 14 may be a cylinder.

[0031] The connecting column 14 is mainly used to connect the outer solid wall 12 and the inner solid wall 11 to strengthen the structural strength of the double wall 1. The number of connecting columns 14 can be set as small as possible under the premise of ensuring that the inner solid wall 11 and the outer solid wall 12 do not deform, which is conducive to reducing the weight of the double wall 1.

[0032] In an illustrative embodiment, Figure 1 As shown, the main structure of the turbine blade formed by the double wall 1 includes a head 3 and a tail 4 opposite to the head 3. The external heat load distribution changes significantly from the head 3 to the tail 4, and the impact holes 111 and the protrusions 13a are arranged in different densities. In the area with higher heat load, the impact holes 111 and the protrusions 13a are arranged more densely.

[0033] In areas with higher heat loads, the impact holes 111 and the protrusions 13a are arranged more densely, which is conducive to more coolant entering the high heat load area to take away more heat. At the same time, the local heat exchange is more uniform, making the blade temperature distribution more uniform and reasonable.

[0034] In an exemplary embodiment, Figure 3 , 4 As shown, the protrusion 13a is a hemispherical structure. The spherical surface of the protrusion 13a faces the inner solid wall 11, and the bottom plane of the protrusion 13a abuts against the outer solid wall 12. The spherical surface of the protrusion 13a is smooth, and the resistance of the coolant is small when it flows through the spherical surface of the protrusion 13a.

[0035] In an exemplary embodiment, Figure 5 , 6 As shown, another protrusion 13b of a cylindrical structure is also proposed. One end of the protrusion 13b is connected to the outer solid wall 12, and the other end of the protrusion 13b faces the inner solid wall 11.

[0036] In an exemplary embodiment, Figure 7 , 8 As shown, another structure of the protrusion 13c is proposed, and the protrusion 13c is a right hexahedron structure. One side of the protrusion 13c abuts against the outer solid wall 12. The protrusion 13c can be a cuboid or a cube. The edges of each protrusion 13c in the length direction are parallel to each other, the edges of each protrusion 13c in the width direction are parallel to each other, and the edges of each protrusion 13c in the height direction are parallel to each other. The protrusion 13c of the right hexahedron structure is easy to process.

[0037] In an exemplary embodiment, Fig. 9 , 10 As shown, another protrusion 13d of a structure is proposed, and the protrusion 13d is a tetrahedron. One surface of the protrusion 13d abuts against the outer solid wall 12. The protrusion 13d has a tip facing the inner solid wall 11.

[0038] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0039] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0040] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

Claims

1. A turbine blade, characterized in that: It comprises a double-layer wall, wherein the double-layer wall comprises an inner solid wall provided with a plurality of impact holes, an outer solid wall and a microstructure unit; There is a gap between the outer solid wall and the inner solid wall, the microstructure unit is arranged on the surface of the outer solid wall facing the inner solid wall so that the side of the outer solid wall facing the inner solid wall is uneven, the microstructure unit includes a plurality of protrusions, and the plurality of protrusions are distributed on the surface of the outer solid wall facing the inner solid wall, and the height of the protrusions is less than one tenth of the distance between the outer solid wall and the inner solid wall; The double-layer wall encloses a main structure of the turbine blade, the inner solid wall is located on the inner side of the outer solid wall, and the inner solid wall encloses a coolant supply cavity, which is connected to each of the impact holes; According to the actual distribution of heat load on the outside of the turbine blade, the impact holes and protrusions are arranged more densely in areas with higher heat load.

2. The turbine blade according to claim 1, characterized in that The protrusion is a hemisphere, a cylinder, a right hexahedron or a tetrahedron.

3. The turbine blade according to claim 1, characterized in that: The number of the protrusions is greater than the number of the impact holes.

4. The turbine blade according to any one of claims 1 to 3, characterized in that The double-layer wall further includes a connecting column arranged between the outer solid wall and the inner solid wall, one end of the connecting column is connected to the inner solid wall, and the other end of the connecting column is connected to the outer solid wall.

5. The turbine blade according to claim 4, characterized in that The number of the impact holes is greater than the number of the connecting posts.

6. The turbine blade according to claim 1, characterized in that The plurality of impact holes are arranged in an array on the inner solid wall, and the plurality of protrusions are arranged in an array on the outer solid wall.

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