Impact insert, bent guide vane and turbine guider

Abstract

The invention provides an impact insert which is arranged in an inner cavity of a bent guide blade and comprises a first section and a second section which are sequentially arranged in the blade height direction of the bent guide blade, the first section and the second section are both configured to be tubular, and the molded line of the tube wall is matched with the shape of the three-dimensional bent inner cavity of the bent guide blade. The opposite ends of the first section and the second section are connected in a sleeved mode, the first end, away from the second section, of the first section is connected to an outer ring of the turbine guider, and the second end, away from the first section, of the second section is connected to an inner ring of the turbine guider. The sectional type tubular structure matched with the three-dimensional inner cavity of the blade in shape is adopted, and the problem of installation interference of an integrated inserting piece in a bending and twisting cavity is solved. All the sections are connected in a sleeved mode through the ends and fixed to the outer ring and the inner ring of the guider respectively, so that the inserting piece obtains stable radial positioning, and meanwhile the stability of the impact distance in the working state can be maintained.

Description

Technical Field

[0001] This disclosure relates to the field of turbine technology, and in particular to an impact insert, a curved guide vane, and a turbine guide. Background Technology

[0002] The turbine guide vane is a key stationary component in a turbine engine, whose blade passages guide and accelerate high-temperature combustion gases to impact the rotor blades. Turbine guide vane blades operate for extended periods in a high-temperature, high-pressure combustion environment, typically requiring an efficient cooling structure to ensure service life and reliability. Impact cooling is a common and highly efficient cooling method, achieved by incorporating impact inserts with impact holes within the blade cavity, guiding cooling air in a jet-like manner to impact the blade's inner wall for enhanced heat transfer.

[0003] For turbine guide vanes with torsional geometry, their inner cavities are complex three-dimensional curved surfaces. This makes it difficult for traditional one-piece impact inserts to be installed into the inner cavity of torsional vanes. Their overall rigid structure is difficult to adapt to the continuously changing cavity shape, which can easily lead to local interference and installation difficulties.

[0004] Meanwhile, during engine operation, the difference in thermal expansion coefficients between the insert and blade materials causes the continuous structure of the insert to constrain thermal expansion, resulting in ineffective release of thermal stress and potential damage to the insert or blade. Furthermore, thermal deformation may alter the preset impact distance, affecting the uniformity and reliability of cooling. Summary of the Invention

[0005] To address at least one of the aforementioned and other technical problems in the related art, this disclosure provides an impact insert disposed within the inner cavity of a curved guide vane, comprising a first segment and a second segment sequentially arranged along the blade height direction of the curved guide vane. Both the first and second segments are configured as tubular, and the profile of the tubular wall is adapted to the shape of the three-dimensional curved inner cavity of the curved guide vane. The facing ends of the first and second segments are sleeved together. The first end of the first segment away from the second segment is connected to the outer ring of a turbine guide, and the second end of the second segment away from the first segment is connected to the inner ring of the turbine guide.

[0006] According to an embodiment of this disclosure, the end of the first segment facing the second segment forms an upper stop, and the end of the second segment facing the first segment forms a lower stop, with the lower stop fitting inside the upper stop.

[0007] According to an embodiment of this disclosure, the inner diameter of the upper stop is configured to be larger than the outer diameter of the lower stop. Specifically, when the impact insert is not exposed to airflow, the lower stop is configured to form a gap with the inner wall of the first segment in the circumferential direction; and when the impact insert is exposed to airflow, the lower stop is configured to abut against the inner wall of the first segment.

[0008] According to an embodiment of the present disclosure, a flange edge is formed at the first end, the outer edge of the flange edge is tightly fitted with the inner edge of the outer ring mounting hole in a nested manner, and is fixedly connected to a continuous connecting portion located at the fitting interface.

[0009] According to embodiments of this disclosure, the second end forms a closed surface, the closed surface having a recess that is recessed toward the interior of the second segment, the recess being configured to engage with a protrusion provided in the inner ring. Alternatively, the closed surface has a protrusion that protrudes away from the second segment, the protrusion being configured to engage with a recess provided in the inner ring.

[0010] According to an embodiment of this disclosure, the first segment and / or the second segment are provided with at least two impact holes arranged along the blade height direction of the curved guide blade, the impact holes penetrating the tube wall of the impact insert.

[0011] According to embodiments of this disclosure, the first segment and / or the second segment are provided with at least three impact holes at uniform intervals along the blade height direction of the curved guide blade.

[0012] According to embodiments of this disclosure, it further includes at least one third segment, which is disposed between the first segment and the second segment and is respectively nested and connected to the first segment and the second segment.

[0013] This disclosure also provides a curved guide vane, including the aforementioned impact insert.

[0014] This disclosure also provides a turbine guide, including the aforementioned impact insert.

[0015] According to the illustrative embodiments of this disclosure, the impact insert employs a tubular structure segmented along the blade height direction with a wall profile adapted to the three-dimensional curved inner cavity shape of the blade. This allows the overall insert to conform to the complex spatial geometry of the curved guide vane cavity, effectively reducing the interference risk of the overall rigid structure during installation and solving the problem of traditional one-piece inserts being difficult to install into curved cavities. Furthermore, by configuring the opposing ends of the first and second segments to interlock, and connecting them to the outer and inner rings of the turbine guide vane respectively, the insert achieves stable radial positioning, avoiding component damage caused by thermal stress concentration and changes in impact distance due to thermal deformation. Attached Figure Description

[0016] The above and other objects, features, and advantages of this disclosure will become clearer from the following description of embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0017] Figure 1 A perspective sectional view of the impact plug during installation according to an embodiment of the present disclosure is shown schematically.

[0018] Figure 2 A perspective cross-sectional view of the impact plug according to an embodiment of the present disclosure is shown schematically;

[0019] Figure 3 A perspective view of an impact plug according to an embodiment of the present disclosure is shown schematically.

[0020] In the accompanying drawings, the meanings of the reference numerals are as follows:

[0021] 1. First section; 11. Upper stop; 12. Flange edge;

[0022] 2. Second section, 21. Lower stop, 22. Closed surface, 23. Recess,

[0023] 3. Turbine guide; 31. Outer ring; 32. Inner ring; 311. Outer ring mounting hole; 321. Protrusion; 4. Impact hole. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0026] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0027] When using expressions such as "at least one of A, B, and C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C. Similarly, when using expressions such as "at least one of A, B, or C," the meaning should generally be interpreted according to the understanding of someone skilled in the art. For example, "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C.

[0028] In the high-pressure turbine section of a gas turbine engine, the turbine guide vane is a stationary component located downstream of the combustion chamber. Its core function is to guide and accelerate the high-temperature combustion gas and impact the rotor blades at a predetermined angle. The turbine guide vane blades are constantly exposed to the high-temperature, high-pressure gas flow. To ensure their structural integrity and service life, effective cooling must be implemented inside the blades. Impact cooling is one such method. It involves installing a thin-walled component called an impact bushing or impact insert inside the blade cavity. Cooling air from the compressor is guided through an array of impact holes on the bushing surface, forming a high-speed jet that directly impacts the inner wall of the blade, thus achieving efficient localized convective heat transfer. For three-dimensional curved-torsion guide vanes designed to optimize aerodynamic performance, their internal cavity shape is a complex spatial curved surface, which presents specific challenges for the design and installation of the impact bushing.

[0029] Traditional impact bushings are typically designed as a single, integral structure. When applied to bent or torsional blades, this integral rigidity presents a mismatch between the blade's rigid structure and the complex, continuously changing three-dimensional geometry of the blade's internal cavity. During installation, the integral bushing needs to pass through an opening at the blade tip and be fully inserted into the bent cavity. The bushing's rigid shape is ill-suited to the curvature variations and narrow sections within the cavity, making it highly susceptible to mechanical interference, which can lead to installation difficulties and even component damage.

[0030] Furthermore, the engine undergoes intense thermal cycling from startup to full-power operation, and the thermal expansion coefficients of the impact bushing material and the blade base material differ. Due to the continuity of its structure, the deformation along the blade height direction of the integral bushing during thermal expansion is geometrically constrained by the blade cavity, and the thermal stress generated by the thermal expansion mismatch cannot be effectively released along the bushing length. This thermal stress concentrates in the area where the bushing contacts the inner cavity wall or in the weak points of the bushing itself. Continuous cyclic thermal stress may cause plastic deformation or cracks in the bushing and may be transmitted to the blade body, accelerating its thermomechanical fatigue. At the same time, thermal deformation changes the pre-designed distance between the impact hole and the target cooling wall of the blade, i.e., the impact distance. Changes in the impact distance directly affect the heat transfer efficiency of the impact jet, leading to insufficient cooling in local areas of the blade, and thus affecting the uniformity and reliability of cooling. Therefore, integral impact bushings face the dual challenges of poor installation adaptability and difficult thermal stress management when applied to complex curved and twisted blades.

[0031] Figure 1 A perspective sectional view of the impact plug installation according to an embodiment of the present disclosure is shown schematically.

[0032] This disclosure provides an impact plugin, such as Figure 1As shown, the inner cavity of the curved guide vane includes a first segment 1 and a second segment 2 arranged sequentially along the blade height direction. Both the first segment 1 and the second segment 2 are configured as tubular, and the profile of the tube wall is adapted to the shape of the three-dimensional curved inner cavity of the curved guide vane. The facing ends of the first segment 1 and the second segment 2 are sleeved together. The first end of the first segment 1 away from the second segment 2 is connected to the outer ring 31 of the turbine guide vane 3, and the second end of the second segment 2 away from the first segment 1 is connected to the inner ring 32 of the turbine guide vane 3.

[0033] In some illustrative embodiments of this disclosure, the impact insert is implemented as a first segment 1 and a second segment 2 arranged sequentially along the blade height direction of the curved guide vane. Both segments are constructed as tubes, and the profile of their tube walls is designed according to the three-dimensional curved surface of the inner cavity of the curved guide vane, so that the outer contour of the insert matches the shape of the inner wall of the blade. The ends of the first segment 1 and the second segment 2 that are close to each other are connected by a sleeve, that is, the end of one segment is inserted into the end of the other segment. The end of the first segment 1 away from the sleeve end is the first end, which is connected to the outer ring 31 of the turbine guide vane 3, and the sleeve end is the second end; the end of the second segment 2 away from the sleeve end is defined as the second end, which is connected to the inner ring 32 of the turbine guide vane 3, and the sleeve end is the first end. That is, from the outer ring 31 to the inner ring 32 of the turbine guide vane 3, the segments are sequentially the first end of the first segment 1, the second end of the first segment 1, the first end of the second segment 2, and the second end of the second segment 2.

[0034] In this implementation, by adopting a segmented tubular structure along the blade height, and with the profile of each segment wall matching the complex three-dimensional curved inner cavity shape of the blade, the originally rigid insert can be disassembled into independent units that are easier to deform and position. This reduces the risk of mechanical interference when inserted into a narrow cavity with continuous bending and twisting characteristics, and solves the problem of difficult installation of traditional integrated impact inserts.

[0035] Furthermore, by configuring the ends of adjacent segments to interlock, the segments are guided and aligned radially, while forming a non-rigid interlocking interface axially. Under heated operating conditions, this effectively releases internal thermal stress caused by thermal expansion mismatch. In addition, by fixing the first end of the first segment 1 and the second end of the second segment 2 to the outer ring 31 and inner ring 32 of the turbine guide vane 3 respectively, a stable and reliable mounting reference and constraint are provided for the entire segmented insert in the engine radial direction. Simultaneously, since each segment is not fixedly connected to the guide vane, their thermal expansion will not affect each other and thus alter the impact distance, which helps maintain the stability of the impact distance.

[0036] Figure 2 A perspective cross-sectional view of the impact plug according to an embodiment of the present disclosure is schematically shown. Figure 3 A perspective view of an impact plug according to an embodiment of the present disclosure is shown schematically.

[0037] According to embodiments of this disclosure, such as Figure 2 and Figure 3 As shown, the end of the first segment 1 facing the second segment 2 forms an upper stop 11, and the end of the second segment 2 facing the first segment 1 forms a lower stop 21, with the lower stop 21 fitted inside the upper stop 11.

[0038] In this implementation, by constructing the connecting ends of adjacent segments as upper stop 11 and lower stop 21 respectively and nesting them together, the lower stop 21 of the second segment 2 is inserted into the upper stop 11 of the first segment 1, providing a clear radial mating surface and axial insertion guide for the two segments, thereby ensuring the alignment accuracy of the axes and the certainty of the relative positions of the two segments during assembly.

[0039] According to embodiments of this disclosure, such as Figure 2 and Figure 3 As shown, the inner diameter of the upper stop 11 is configured to be larger than the outer diameter of the lower stop 21. Specifically, when the impact insert is not exposed to airflow, the lower stop 21 is configured to form a gap with the inner wall of the first segment 1 in the circumferential direction; and when the impact insert is exposed to airflow, the lower stop 21 is configured to abut against the inner wall of the first segment 1.

[0040] In some illustrative embodiments of this disclosure, the inner diameter of the upper stop 11 is set to be larger than the outer diameter of the lower stop 21. When the impact plug is installed or stationary at room temperature without cooling airflow, a uniform annular gap exists circumferentially between the entire outer circumferential surface of the lower stop 21 and the inner wall surface of the upper stop 11. When the impact plug is in operation, the airflow pressure inside the plug is high, while the gap between the plug and the inner cavity contains low-pressure airflow after impact. The airflow pressure difference between the inside and outside of the plug causes the lower stop 21 to expand outward. At the same time, the two plug sections expand due to heat, thereby changing the fit between the outer circumferential surface of the lower stop 21 and the inner wall surface of the upper stop 11 from a clearance fit to an abutment fit.

[0041] In the embodiments of this disclosure, the connecting end of the first segment 1 constitutes the receiving party, and the connecting end of the second segment 2 constitutes the receiving party, and the two are connected by a socket connection.

[0042] The second end of the first segment 1 is bent or expanded radially outward to form an upper stop 11, which serves as the receiving end, while the first end of the second segment 2 extends with its original diameter to form a lower stop 21, which serves as the receiving end; alternatively, the second end of the first segment 1 maintains its original diameter as the upper stop 11, while the first end of the second segment 2 contracts radially inward to form the lower stop 21; or alternatively, the first end of the first segment 1 expands outward, while the first end of the second segment 2 contracts inward. As long as the inner contour dimension of the receiving structure is larger than the outer contour dimension of the receiving structure in the socket area, an initial annular assembly gap can be formed between the two. This gap provides guidance and tolerance for assembly at room temperature and allows the receiving structure to expand radially due to thermal expansion during operation, ultimately achieving a tight contact with the inner wall of the receiving structure.

[0043] In this implementation, the connection relationship is designed as a clearance fit during operation, which can be converted to abutment during operation, allowing the connection structure to adapt to changes in operating temperature. Thus, during cold installation, the clearance avoids forced constraints caused by manufacturing tolerances or assembly stress; during hot operation, the thermal expansion of the lower stop 21 actively eliminates the clearance and forms a tight abutment. This method of establishing a stable connection autonomously by thermal load allows the structure to effectively release cold-state stress during thermal cycling while maintaining the necessary radial support stiffness and sealing at operating temperatures, thereby ensuring the overall structural integrity and positional stability of the impact plug under high-temperature operating conditions.

[0044] According to embodiments of this disclosure, such as Figure 1 and Figure 2 The first end shown forms a flange edge 12. The outer edge of the flange edge 12 is tightly fitted with the inner edge of the outer ring mounting hole 311 in a nested manner, and is fixedly connected to the continuous connecting part located at the fitting interface.

[0045] In some illustrative embodiments of this disclosure, the first end of the first segment 1 is provided with a radially outwardly extending flange edge 12. The outer circumferential contour of the flange edge 12 is adapted to the inner edge contour of the corresponding mounting hole on the outer ring 31 of the turbine guide 3, and the two are tightly fitted in a nested manner. A continuous connecting portion is provided on the entire circumference at the fitting interface, and the connecting portion achieves a fixed connection between the flange edge 12 and the outer ring 31 through processes such as welding and brazing.

[0046] In this implementation, by providing a radially extended flange edge 12 at the end of the first segment 1, and tightly nesting its outer edge with the inner edge of the outer ring mounting hole 311 in a shape-matching manner, precise radial and circumferential initial positioning is provided for the impact insert, thereby ensuring the accuracy of the overall installation position of the insert in the engine's radial coordinate system. By providing a continuous connecting portion at the nesting interface and fixing the two together, the radial and circumferential loads borne by the impact insert can be effectively transferred to the rigid outer ring 31 structure through this connecting portion; the continuous connection also constitutes a sealing interface, which can prevent cooling gas from leaking out from there.

[0047] According to embodiments of this disclosure, such as Figure 1 and Figure 3 As shown, the second end forms a closed surface 22, which has a recess 23 that is recessed toward the interior of the second segment 2. The recess 23 is configured to engage with a protrusion 321 provided in the inner ring 32. Alternatively, the closed surface 22 has a protrusion 321 that protrudes away from the second segment 2, and the protrusion 321 is configured to engage with the recess 23 provided in the inner ring 32.

[0048] In some illustrative embodiments of this disclosure, the second end of the second segment 2 is constructed as a closed end face. A positioning structure is formed on this closed end face, which is fitted and connected to a pre-set structure on the inner ring 32 of the turbine guide 3 through shape matching. Specifically, a recess 23 is machined on the closed end face that is recessed towards the inside of the second segment 2, and a corresponding protrusion 321 is provided on the inner ring 32, with the recess 23 fitting with the protrusion 321; or a protrusion is machined on the closed end face that protrudes outward from the second segment 2, and a corresponding recess is provided on the inner ring, with the protrusion fitting with the recess. The cross-sectional shape of the recess and the protrusion can be a circular, rectangular, or annular structure, etc., with direct draft characteristics.

[0049] In this implementation, by providing a closed surface 22 at the end of the second segment 2 and constructing a recess 23 or a protrusion, which engages with the corresponding complementary structure on the inner ring 32, precise radial and circumferential mechanical positioning is provided for the inner ring 32 end of the impact insert. This engagement connection method constrains the radial displacement and rotation of the insert relative to the inner ring 32 during operation, thus cooperating with the fixed connection between the first end and the outer ring 31 via the flange edge 12, jointly determining the complete installation span and spatial orientation of the insert in the radial direction. The closed end face also serves to block airflow and guide all cooling air out through the preset impact hole 4. The concave-convex engagement positioning method, under thermal load, allows the mating surfaces to adapt to thermal deformation to a certain extent, and works in conjunction with the connection structure at the first end to release thermal stress while maintaining the stability of the overall insert structure, providing constraint for maintaining a constant impact distance.

[0050] According to embodiments of this disclosure, such as Figures 1 to 3As shown, the first segment 1 and / or the second segment 2 are provided with at least two impact holes 4 arranged along the blade height direction of the curved guide blade, and the impact holes 4 penetrate the tube wall of the impact insert.

[0051] In some illustrative embodiments of this disclosure, at least two impact holes 4 are provided and arranged along the blade height direction of the curved guide vane. These impact holes 4 penetrate the tube walls of the first section 1 and the second section 2, or penetrate the tube walls of both sections simultaneously. The central axis of the impact holes 4 is typically configured to be perpendicular to the local tube wall curvature at the opening location of the impact insert, and the diameter and spacing of the holes are designed based on the heat transfer and airflow parameters of the target cooling area.

[0052] Specifically, within the internal cavity of the curved guide vane, the heat load varies significantly across different regions. Taking the leading edge region as an example, this area directly experiences the frontal impact of high-temperature combustion gases, resulting in the highest heat flux density. Therefore, the corresponding insert section wall in this region typically requires relatively large or densely distributed impact holes 4 to provide sufficient mass flow rate of cooling air and enhance the impact heat transfer intensity. Furthermore, the impact holes 4 directly opposite the leading edge stagnation line have the largest diameter and / or the smallest spacing.

[0053] For the pressure and suction surfaces, the heat load distribution changes along the flow direction. In the central region near the leading edge, the heat load remains high, and the diameter and density of the impingement holes 4 need to be maintained at a high level. As the flow progresses towards the trailing edge, the heat load generally decreases gradually, and the diameter of the impingement holes 4 can be reduced accordingly and / or the spacing increased to achieve optimized distribution of cooling air.

[0054] In the trailing edge region, the internal cavity structure becomes narrower and is often combined with film cooling or turbulence column structures. The design of the impact holes 4 here needs to balance structural strength and cooling requirements, and a small-diameter, high-density array can be used. In addition, the opening direction of the impact holes 4 is perpendicular to the local plug-in profile at its location to ensure that the jet impacts the target wall perpendicularly, thereby obtaining consistent impact distance and heat transfer efficiency in all areas.

[0055] In addition, the impact holes 4 can be arranged in a single row in a straight line or in multiple rows in an alternating pattern to adapt to the heat load distribution in different areas of the inner wall of the blade.

[0056] In this implementation, multiple through-holes 4 are formed in the tube wall of the first segment 1 and / or the second segment 2 along the blade height direction, allowing the cooling air entering the insert to be ejected at high speed from these holes, forming multiple impact jets. These jets impact the corresponding areas of the blade's inner wall vertically or nearly vertically, converting the kinetic energy of the cooling air into intense local convective heat transfer, thereby efficiently removing heat from the blade wall and achieving critical cooling of the high-temperature blade. This method of opening holes based on segmented inserts allows the arrangement of the impact holes 4 on each insert segment to be independently optimized to better adapt to the local shape and cooling requirements of its corresponding cavity segment, enhancing design flexibility and providing a foundation for achieving uniform and effective impact cooling in complex, tortuous cavities.

[0057] According to embodiments of this disclosure, such as Figures 1 to 3 As shown, at least three impact holes 4 are evenly spaced along the blade height direction of the curved guide blade in the first segment 1 and / or the second segment 2.

[0058] In some illustrative embodiments of this disclosure, the arrangement of the impact holes 4 is further defined as follows: they are opened at uniform intervals along the blade height direction of the curved guide vane on the pipe wall of the first section 1, the pipe wall of the second section 2, or simultaneously on the pipe walls of both sections. This arrangement requires that the number of impact holes 4 be at least three, and the center distance between adjacent impact holes 4 remains constant in the blade height direction. The central axis of the impact hole 4 is perpendicular to the local curved surface of the pipe wall at its location and penetrates the pipe wall.

[0059] In this implementation, by arranging the impact holes 4 at uniform intervals along the blade height direction, the cooling air jet ejected from the insert can cover the target area of ​​the blade's inner wall in a continuous and regular radial direction. The uniform spacing design allows the distribution of the cooling airflow to match the continuous variation trend of the blade's radial heat load, resulting in more uniform heat transfer on the wall surface and avoiding localized overheating caused by uneven cooling.

[0060] According to embodiments of this disclosure, it further includes at least one third segment, which is disposed between the first segment 1 and the second segment 2, and is respectively nested and connected to the first segment 1 and the second segment 2.

[0061] In some illustrative embodiments of this disclosure, the impact insert further includes at least one third segment disposed between the first segment 1 and the second segment 2. The third segment is constructed as a tube, with its wall profile adapted to the shape of the corresponding blade inner cavity segment. Both ends of the third segment are connected to adjacent insert segments via a sleeve connection; that is, the first end of the third segment is sleeved on or fitted by the second end of the first segment 1; the second end of the third segment is similarly sleeved on the first end of the second segment 2. When more than one third segment is required, these intermediate segments are sequentially sleeved end-to-end, forming a connection sequence between the first segment 1 and the second segment 2, wherein any two adjacent insert segments are connected by a sleeve connection. Further, the sleeve connection employs the aforementioned stop structure and / or forms a clearance fit.

[0062] In this implementation, by introducing at least one third segment between the first segment 1 and the second segment 2, the impact insert can be divided into more independent fitting units along the blade height direction. Specifically, by increasing the number of intermediate segments, the axial length of the blade cavity corresponding to each segment is shortened, allowing the profile of each segment's tube wall to fit the complex bending and twisting features of the cavity it covers with higher precision. This reduces the dependence on the overall insert forming accuracy and assembly accuracy, improving manufacturing feasibility and assembly error tolerance.

[0063] Furthermore, more segments mean the introduction of more relatively sliding socket connection interfaces within the insert. These interfaces work together to provide more paths and capacity for releasing axial thermal expansion strain, allowing thermal stress caused by temperature gradients or material differences to be more effectively dispersed and dissipated at multiple connections, thereby further reducing the risk of structural failure due to thermal stress concentration. This modular and scalable segmented design allows the impact insert of the same basic structure to flexibly adapt to various turbine guide vanes with different blade heights or degrees of bending and twist by adjusting the number of intermediate segments, enhancing its versatility and engineering applicability.

[0064] In some illustrative embodiments of this disclosure, the number of segments is determined based on the blade height of the curved guide vane, the geometric complexity of the internal cavity curvature, and the cooling zone requirements. For blades with shorter blade height or lower curvature, a two-segment structure is adopted, consisting only of the first segment 1 and the second segment 2 directly fitted together, which is sufficient to adapt to the internal cavity shape and complete the cooling coverage. For blades with medium blade height or obvious three-dimensional curvature, a third segment is introduced to form a three-segment structure; the third segment is located between the first segment 1 and the second segment 2, fitting together with both, thereby dividing the entire insert into three independent adaptation units that better fit the local cavity.

[0065] For blades with large height or complex bending, a multi-segment structure is adopted, that is, two or more third segments are continuously set between the first segment 1 and the second segment 2; the third segments are connected end to end in sequence to form a modular plug-in system that can flexibly adapt to long spans and continuously changing complex cavities. The increase in the number of segments reduces the axial length and geometric change range that each single segment needs to cover, and improves manufacturing accuracy and assembly feasibility.

[0066] The length ratio of each insert segment along the blade height is differentiated based on the geometric characteristics and cooling requirements of the corresponding blade cavity region. For example, in the leading edge region of the blade, the curvature of the cavity often changes drastically, and the heat load is also the highest; the insert segment corresponding to this region may need to be designed to be relatively short so that its profile can more accurately fit the complex local surface and provide sufficient space for arranging high-density impact holes 4. In the middle or trailing edge region of the blade, the shape of the cavity may tend to be gentler, and the length of the corresponding insert segment is appropriately increased to simplify the structure and reduce the number of connection interfaces. Through this non-uniform length segmented design, a more optimized local shape fit and cooling effect distribution are achieved, thereby improving the overall cooling efficiency and structural adaptability.

[0067] In some illustrative embodiments of this disclosure, the impact insert is made of a heat-resistant alloy material that maintains good strength and oxidation resistance at high temperatures, such as nickel-based or cobalt-based superalloys. When selecting materials, alloys with a coefficient of thermal expansion similar to or slightly lower than that of the blade base material are preferred for manufacturing the impact insert. Choosing materials with similar coefficients of thermal expansion allows the expansion of the insert and the blade to be synchronized when heated, thereby controlling the changes in working clearance and the restraint stress caused by the difference in expansion to a lower level.

[0068] Furthermore, the manufacturing of each segment can be carried out using various processes depending on cost, complexity, and batch size. For segments with complex shapes and multiple rows of impact holes 4, investment casting can be used to form them as a single piece, and then CNC machining or EDM can be used to refine the impact holes 4 to ensure dimensional and burr control.

[0069] In the assembly process disclosed herein, the segmented impact inserts are inserted into the inner cavity of the curved guide vane using a specialized assembly fixture. Specifically, with the positioning and assistance of the fixture, each insert segment can be pushed into the inner cavity in the order determined by the design along the blade height. The insert segments are connected by the exposed stop structure of the previous insert segment and the corresponding stop structure of the next insert segment, and this connection process naturally provides guidance and alignment. After all insert segments are pushed in sequentially and connected, they are finally fixed at both ends. This assembly method, which combines the fixture with the inherent guiding and alignment functions of the connection structure, simplifies the assembly operation in the invisible and complex cavity, reducing assembly difficulty and the risk of damage.

[0070] As an example, the second segment 2 is first installed using a tooling fixture, then each plug-in segment is pushed in sequentially and connected, and finally the first segment 1 is installed. In an embodiment where the third segment is not set, the second segment 2 is installed first, followed by the first segment.

[0071] This disclosure also provides a curved guide vane, including the aforementioned impact insert.

[0072] Based on similar inventive concepts, the curved guide vane also has similar or identical features to the above-described embodiments, and also has similar or identical functions based on these features, therefore, it will not be described in detail again.

[0073] This disclosure also provides a turbine guide, including the aforementioned impact insert.

[0074] Based on similar inventive concepts, the turbine guide also has similar or identical features to the above-described embodiments, and also has similar or identical functions based on these features; therefore, it will not be described in detail again.

[0075] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are identified by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure.

[0076] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. An impact insert, disposed within the inner cavity of a curved guide vane, characterized in that, It includes a first segment and a second segment arranged sequentially along the blade height direction of the curved guide blade. Both the first segment and the second segment are configured as tubular, and the profile of the tube wall is adapted to the shape of the three-dimensional curved inner cavity of the curved guide blade. The ends of the first segment and the second segment facing each other are sleeved together. The first end of the first segment away from the second segment is connected to the outer ring of the turbine guide, and the second end of the second segment away from the first segment is connected to the inner ring of the turbine guide.

2. The impact insert according to claim 1, characterized in that, The first segment forms an upper stop at the end facing the second segment, and the second segment forms a lower stop at the end facing the first segment, with the lower stop fitting inside the upper stop.

3. The impact insert according to claim 2, characterized in that, The inner diameter of the upper stop is configured to be larger than the outer diameter of the lower stop; Specifically, when the impact plug is not exposed to airflow, the lower stop is configured to form a gap with the inner wall of the first segment in the circumferential direction, and when the impact plug is exposed to airflow, the lower stop is configured to abut against the inner wall of the first segment.

4. The impact insert according to claim 1, characterized in that, The first end forms a flange edge, the outer edge of which is closely fitted with the inner edge of the outer ring mounting hole in a nested manner, and is fixedly connected to the continuous connecting part located at the fitting interface.

5. The impact insert according to claim 1, characterized in that, The second end forms a closed surface, the closed surface having a recess that is recessed toward the interior of the second segment, the recess being configured to engage with a protrusion provided in the inner ring; Alternatively, the closed surface has a protrusion facing away from the second protrusion, the protrusion being configured to engage with a recess provided in the inner ring.

6. The impact insert according to claim 1, characterized in that, The first segment and / or the second segment are provided with at least two impact holes arranged along the blade height direction of the curved guide blade, the impact holes penetrating the tube wall of the impact insert.

7. The impact insert according to claim 6, characterized in that, The first segment and / or the second segment are provided with at least three impact holes at uniform intervals along the blade height direction of the curved guide blade.

8. The impact insert according to claim 1, characterized in that, It also includes at least one third segment, which is disposed between the first segment and the second segment and is respectively nested and connected to the first segment and the second segment.

9. A curved guide vane, characterized in that, Including the impact plug as described in any one of claims 1-8.

10. A turbine guide, characterized in that, Including the impact plug as described in any one of claims 1-8.

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