Shrinkage type turbine blade trailing edge crack structure, design method and turbine equipment
By designing a gradually narrowing slit structure at the trailing edge of the turbine blade, the problem of stress concentration at the trailing edge of the turbine blade was solved, the risk of failure was reduced, and the performance and lifespan of the equipment were improved.
Patent Information
- Application Number
- CN202511365743.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-23
- Publication Date
- 2025-11-18
AI Technical Summary
The trailing edge slotted structure of turbine blades is subject to stress concentration under high temperature and high pressure, which leads to the risk of failure. Existing designs have failed to effectively solve the problems of strength and structural reliability.
A shrinkable turbine blade trailing edge slit structure is designed. By gradually narrowing the slits within the rounded corner area of the blade, and designing slits of different widths according to the strength margin and reliability at different locations, stress concentration is reduced.
This reduces the risk of turbine blade failure, improves equipment performance and service life, while maintaining the original cooling effect.
Smart Images
Figure CN120968754A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of turbine equipment technology, specifically to a shrinkable turbine blade trailing edge slit structure, design method, and turbine equipment. Background Technology
[0002] As a core component of gas turbines, turbine blades operate under high temperature and high pressure environments for extended periods. The design of their trailing edge cooling structure directly affects blade life, aerodynamic efficiency, and overall turbine performance. Slit-type structures are one of the traditional cooling methods for turbine blade trailing edges.
[0003] The arrangement of the slits in the middle of turbine blades is usually controlled by the width and spacing of the slits. Although it has the advantages of simple structure and convenient casting, it does not take into account the strength design and structural reliability. In the area where the trailing edge of the blade intersects with the rounded edge of the blade, there is often a large stress concentration due to geometric nonlinearity, which leads to the failure risk point at this location. Summary of the Invention
[0004] The present invention aims to at least partially solve one of the technical problems in the related art.
[0005] To address this, embodiments of the present invention propose a shrinkable turbine blade trailing edge slit structure. This shrinkable turbine blade trailing edge slit structure arranges slits in a gradually narrowing trend within the rounded corner area of the blade body. It can design slits of different widths according to the strength margin and reliability at different locations, thereby reducing stress concentration at the trailing edge slit and lowering the failure risk of the turbine blade.
[0006] The present invention relates to a shrinkable turbine blade trailing edge slit structure. The turbine blade includes a blade body and a blade root. The blade body is connected to the rim plate of the blade root. The trailing edge region of the blade body is provided with a plurality of slits spaced apart along the height direction of the blade body. The area of the trailing edge region adjacent to the rim plate is a high-stress region. In the thickness direction of the blade body, the size of the slits in the high-stress region gradually decreases along the direction closer to the rim plate.
[0007] The shrinkable turbine blade trailing edge slotted structure of this invention has multiple slots spaced apart along the height direction of the blade body in the trailing edge region. The area of the trailing edge region adjacent to the rim plate is a high-stress area. In the thickness direction of the blade body, the size of the slots in the high-stress area gradually decreases along the direction closer to the rim plate. Therefore, by arranging each slot in a gradually narrowing trend within the rounded corner area of the blade body, this application can design slots of different widths according to the strength margin and reliability at different locations, thereby reducing stress concentration at the trailing edge slots and lowering the failure risk of the turbine blade.
[0008] In some embodiments, in the height direction of the blade, the spacing between adjacent cleavages in the high-stress zone gradually decreases along the direction close to the rim plate.
[0009] In some embodiments, at least two splits of different sizes exist within the high-stress zone in the height direction of the blade.
[0010] The design method of the trailing edge slotted structure of the retractable turbine blade according to the present invention includes: defining the area adjacent to the blade root in the trailing edge region as a high-stress region; obtaining the cold air flow area of the trailing edge slotted structure in the high-stress region of a conventional turbine blade and defining it as a fixed flow area; and, while keeping the fixed flow area unchanged, allocating the aspect ratio and spacing of each slotted structure according to the trend of gradual contraction.
[0011] The design method of the shrinking turbine blade trailing edge slot structure in this invention obtains the cold air flow area of the trailing edge slot in the high stress zone of a conventional turbine blade, and distributes the length-to-width ratio and spacing of each slot according to a gradually shrinking trend while keeping the total flow area unchanged. This allows for the design of slots with different widths based on the strength margin and reliability at different locations, thereby reducing stress concentration at the trailing edge slot and lowering the failure risk of the turbine blade, without affecting the original cooling effect.
[0012] In some embodiments, the design method of the trailing edge slot structure of the retractable turbine blade further includes: obtaining the stress concentration coefficient of each slot, and adjusting the aspect ratio and spacing of each slot according to the stress concentration coefficient.
[0013] In some embodiments, the design method of the trailing edge slotted structure of the retractable turbine blade further includes:
[0014] When the stress concentration system is less than 1, a three-dimensional finite element analysis is performed on the split structure.
[0015] In some embodiments, the design method of the trailing edge slotted structure of the retractable turbine blade further includes:
[0016] When the stress concentration factor is greater than 1, the aspect ratio and spacing of the splits are redistributed until the stress concentration factor is less than 1, and then the structure of the splits is subjected to three-dimensional finite element analysis.
[0017] In some embodiments, the design method of the trailing edge slotted structure of the retractable turbine blade further includes:
[0018] Determine whether the strength and low-cycle fatigue life analysis criteria are met based on three-dimensional finite element analysis.
[0019] If the conditions are met, output the dimensions of the splitting structure.
[0020] In some embodiments, the design method of the trailing edge slotted structure of the retractable turbine blade further includes:
[0021] If the strength and low-cycle fatigue life analysis criteria are not met, the number of splits is increased and the aspect ratio and spacing of the splits are redistributed until the requirements are verified by three-dimensional finite element analysis, and then the dimensions of the split structure are output.
[0022] The turbine device of this invention includes the shrinkable turbine blade trailing edge slotted structure described in the above embodiments.
[0023] The turbine equipment of this invention adopts the above-mentioned shrinkable turbine blade trailing edge slit structure. Each slit is arranged in a gradually narrowing trend within the rounded corner area of the blade. Slits of different widths can be designed according to the strength margin and reliability at different locations, thereby reducing stress concentration at the trailing edge slits, reducing the failure risk of the turbine blade, and resulting in good turbine equipment performance and long service life. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the trailing edge slit structure of a retractable turbine blade according to an embodiment of the present invention.
[0025] Figure 2 This is a schematic diagram of the slit arrangement of the trailing edge slit structure of a retractable turbine blade according to an embodiment of the present invention.
[0026] Figure 3 A flowchart illustrating the design method of the trailing edge slotted structure for a retractable turbine blade.
[0027] Figure label:
[0028] 1. Leaf body, 2. Leaf root, 3. Edge plate, 4. Split slit, 5. High stress zone. Detailed Implementation
[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0030] like Figure 1 and Figure 2 As shown in the embodiment of the present invention, the turbine blade includes a blade body 1 and a blade root 2. The blade body 1 is connected to the blade root 2 on the edge plate 3. The trailing edge region of the blade body 1 is provided with a plurality of slits 4 arranged at intervals along the height direction of the blade body. The area of the trailing edge region adjacent to the edge plate 3 is a high stress region 5. In the thickness direction of the blade body, the size of the slits 4 in the high stress region 5 gradually decreases along the direction close to the edge plate 3.
[0031] It is understandable that the high-stress zone 5 can be understood as the blade fillet area formed at the connection between the blade 3 and the blade body 1. This area is simultaneously subjected to temperature load and centrifugal load, and is also affected by geometric nonlinearity, making it a low-life region. In traditional schemes, the slits 4 in this region are still arranged with equal thickness, without considering the strength margin of different trailing edge regions. However, in this application, the width of the slits 4 is gradually reduced in the direction closer to the blade 3 within the high-stress zone 5. That is, the greater the stress concentration, the narrower the width of the slits 4, which can correspondingly increase the structural strength at the corresponding position, thereby reducing the impact of stress concentration.
[0032] The shrinkable turbine blade trailing edge slotted structure of this invention has multiple slots 4 spaced apart along the height direction of the blade body 1 in the trailing edge region. The area of the trailing edge region adjacent to the rim plate 3 is a high-stress region 5. In the thickness direction of the blade body, the size of the slots 4 in the high-stress region 5 gradually decreases along the direction close to the rim plate 3. Thus, by arranging each slot 4 in a gradually narrowing trend in the rounded corner region of the blade body, this application can design slots 4 with different widths according to the strength margin and reliability at different positions, thereby reducing the stress concentration phenomenon at the trailing edge slots 4 and reducing the failure risk of the turbine blade.
[0033] In some embodiments, such as Figure 2 As shown, in the height direction of the blade, the spacing between adjacent slits 4 in the high-stress zone 5 gradually decreases towards the rim plate 3. In other words, the closer the slits 4 are to the rim plate 3, the smaller the spacing and the higher the density of the slits.
[0034] It should be noted that the rounded corner area of the blade is a high-temperature area with a large cooling demand. By arranging the slits 4 in a high density in this area, the cooling flow area can be increased, thereby increasing the cooling capacity and meeting the heat exchange requirements at this location.
[0035] Optionally, such as Figure 2 As shown, in the height direction of the blade, there are at least two slits 4 of different sizes in the high-stress zone 5. In other words, the height of each slit 4 does not need to be consistent. The design is mainly based on meeting the cooling requirements. For example, if the cooling requirement at a certain position is large, the height of the slit 4 at that position can be increased, and vice versa.
[0036] In addition, the height adjustment of each slit 4 can also be used to balance the total cooling flow area.
[0037] like Figure 3 As shown, the design method of the trailing edge slotted structure of the retractable turbine blade according to an embodiment of the present invention includes:
[0038] The region adjacent to the leaf root 2 in the trailing edge area is defined as the high-stress region 5;
[0039] Obtain the cold air flow area of the trailing edge slit 4 in the high-stress zone 5 of a conventional turbine blade and define it as a fixed flow area.
[0040] While keeping the flow area constant, the aspect ratio and spacing of each slit 4 are allocated according to the trend of gradual contraction.
[0041] The design method of the shrinking turbine blade trailing edge slot structure in this invention obtains the cold air flow area of the trailing edge slot 4 in the high stress zone 5 of a conventional turbine blade, and distributes the aspect ratio and spacing of each slot 4 according to a gradually shrinking trend while keeping the total flow area unchanged. This allows for the design of slots 4 with different widths based on the strength margin and reliability at different locations, thereby reducing stress concentration at the trailing edge slot 4 and lowering the failure risk of the turbine blade, without affecting the original cooling effect.
[0042] Furthermore, the design method for the trailing edge slotted structure of a contracting turbine blade also includes: obtaining the stress concentration factor of each slot 4, and adjusting the aspect ratio and spacing of each slot 4 according to the stress concentration factor. It should be noted that the dimensions of each slot 4 must be adjusted while keeping the total flow area constant. Specifically, the stress concentration factor K is defined as K = f(m,H,n,L), where m is the width of the slot 4, L is the height of the slot 4, H is the spacing between the slots 4, n is the trailing edge diameter, a, b, and c are correlation coefficients, and i is the order of the slots 4. Then, the following condition is met:
[0043] K i =(m i / m i-1 ) a .(n / m i ) b .(H i / (H i -L i )) c
[0044] The correlation coefficients a, b, and c are given based on long-term design experience, and the design must satisfy m. i / m i-1 <1,3<n / m i <10,1<H i / (H i -L i <3.
[0045] Furthermore, when the stress concentration system is less than 1, a three-dimensional finite element analysis is performed on the structure of split 4. Then, based on the three-dimensional finite element analysis, it is determined whether the strength and low-cycle fatigue life analysis criteria are met. If they are met, the structural dimensions of split 4 can be output.
[0046] In addition, when the stress concentration factor is greater than 1, the aspect ratio and spacing of the split 4 need to be redistributed until the stress concentration factor is less than 1 before the structure of the split 4 is subjected to three-dimensional finite element analysis.
[0047] In addition, if the three-dimensional finite element analysis determines that the structural dimensions of the split 4 do not meet the strength and low-cycle fatigue life analysis criteria, then it is necessary to increase the number of split 4 and redistribute the aspect ratio and spacing of the split 4 until the requirements are verified by the three-dimensional finite element analysis, and then output the structural dimensions of the split 4.
[0048] It should be noted that after each reallocation of the aspect ratio and spacing of the split 4, it is necessary to re-evaluate whether the stress concentration factor, total flow area, and three-dimensional finite element analysis meet the output requirements. If any of these requirements are not met, reallocation is required.
[0049] The turbine device of this invention includes the shrinkable turbine blade trailing edge slit structure of the above-described embodiments.
[0050] The turbine equipment of this invention adopts the above-mentioned shrinkable turbine blade trailing edge slit structure, and arranges each slit 4 in the rounded corner area of the blade body in a gradually narrowing trend. According to the strength margin and reliability of different positions, the slit 4 with different widths can be designed accordingly, thereby reducing the stress concentration phenomenon at the trailing edge slit 4, reducing the failure risk of the turbine blade, and the turbine equipment has good performance and long service life.
[0051] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0053] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0054] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0055] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0056] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A shrunken turbine blade trailing edge split structure, characterized by, The turbine blade comprises a blade body and a blade root, the blade body is connected to the edge plate of the blade root, the trailing edge region of the blade body is provided with a plurality of split joints arranged along the height direction of the blade body, and the region adjacent to the edge plate of the trailing edge region is a high stress region, and in the thickness direction of the blade body, the size of the split joint in the high stress region gradually decreases in the direction close to the edge plate.
2. The shrunk turbine blade trailing edge split structure according to claim 1, characterized in that, In the height direction of the blade body, the interval size of adjacent split joints in the high stress region gradually decreases in the direction close to the edge plate.
3. A shrunk turbine blade trailing edge split structure according to claim 1 or 2, characterized in that In the height direction of the blade body, there are at least two split joints with different sizes in the high stress region.
4. A method of designing a split trailing edge structure for a convergent turbine blade, characterized by, Comprise: Define the region adjacent to the blade root of the trailing edge region as a high stress region; Obtain the cold air passage area of the trailing edge split joint of the high stress region of the conventional turbine blade and define it as a fixed passage area; Under the premise of keeping the fixed passage area unchanged, the length-width ratio and the interval of each split joint are allocated in a gradually converging trend.
5. The method of designing a trailing edge split of a stator blade of a turbomachine according to claim 4, characterized in that, Also include: Obtain the stress concentration coefficient of each split joint, and adjust the length-width ratio and the interval of each split joint according to the stress concentration coefficient.
6. The method of designing a trailing edge split of a shrouded turbine blade according to claim 5, wherein Also include: When the stress concentration coefficient is less than 1, perform three-dimensional finite element analysis on the structure of the split joint.
7. The method of designing a trailing edge split of a shrouded turbine blade according to claim 6, wherein Also include: When the stress concentration coefficient is greater than 1, re-allocate the length-width ratio and the interval of the split joint until the stress concentration coefficient is less than 1, and then perform three-dimensional finite element analysis on the structure of the split joint.
8. The method of designing a trailing edge split of a shrouded turbine blade according to claim 7, wherein Also include: Determine whether the strength and low-cycle fatigue life analysis criteria are met according to the three-dimensional finite element analysis; If it is met, output the split joint structure size.
9. The method of designing a trailing edge split of a shrouded turbine blade according to claim 8, wherein Also include: If the strength and low-cycle fatigue life analysis criteria are not met, increase the number of split joints and re-allocate the length-width ratio and the interval of the split joint until the three-dimensional finite element analysis verifies that the requirements are met, and then output the split joint structure size.
10. A turbomachine, characterized in that Comprise the converging turbine blade trailing edge split joint structure according to any one of claims 1-3.