A turbine radial rim seal structure and method of designing the same

Abstract

The present application relates to the technical field of gas turbine turbine sealing, and particularly discloses a turbine radial rim sealing structure and a design method thereof. The turbine radial rim sealing structure comprises a static disc and a dynamic disc. The static disc is used for matching the end of the dynamic disc, has axially outward convex static disc sealing teeth, and the end of the static disc sealing teeth has radially inward folded static tooth inward folding portions. The dynamic disc is used for matching the end of the static disc, has axially outward convex dynamic disc sealing teeth, and the end of the dynamic disc sealing teeth has radially outward folded dynamic tooth outward folding portions. The dynamic tooth outward folding portions and the static tooth inward folding portions form a mutual embedding staggered matching relationship in the turbine axial direction, have static tooth-dynamic tooth axial matching gaps and static tooth-dynamic tooth radial overlapping matching widths, so that the static disc and the dynamic disc are matched in an axial labyrinth type sealing structure, and a fluid channel capable of containing high-temperature gas invasion into a turbine disc cavity by sealing cold gas is formed. The present application effectively increases the flow path of high-temperature main flow invading the turbine disc cavity, and has good overheating prevention effect on the turbine disc.

Description

Technical Field

[0001] This invention relates to the field of gas turbine sealing technology, specifically a turbine radial rim sealing structure and its design method. Background Technology

[0002] Two key indicators of gas turbine development are the increase in compressor pressure ratio and turbine inlet temperature. Currently, the inlet temperature of gas turbine turbines far exceeds the temperature resistance limits of existing materials. The main causes of failure in hot-end components include reduced internal strength due to excessive temperature differences, and deformation and thermal corrosion caused by localized overheating, leading to creep fracture of the blades. This reduces blade life and affects operational safety. Therefore, advanced secondary air systems are needed to prevent overheating of hot-end components such as blades and turbine discs, thereby improving the engine's operational safety and reliability.

[0003] In order to prevent the turbine disk from overheating, the secondary air system is used to seal the intrusion of the high-temperature main flow of the turbine into the turbine disk cavity at the radial rim between the stationary disk (which is part of the stationary blade baffle) and the rotating disk (which is part of the rotating disk). In other words, the sealing cold air of the secondary air system increases the flow resistance of the high-temperature intrusion flow into the turbine disk cavity, thereby inhibiting the intrusion of the combustion gas into the disk cavity.

[0004] To ensure the effectiveness of the sealing gas in suppressing the high-temperature intrusion flow from the turbine, the best approach is typically to create a complex sealing structure at the turbine radial rim, formed by the stationary and moving disks, to increase the flow resistance of the high-temperature intrusion flow into the turbine disk cavity. However, repeated simulations have revealed that a more complex sealing structure at the turbine radial rim is not necessarily better. A complex sealing structure alters the local flow structure and increases aerodynamic losses. This causes the sealing gas outflow to mix with the mainstream flow, changing the pressure distribution and corresponding load on the blade surface near the turbine radial rim endwall, and negatively impacting the characteristics of the downstream turbine stage.

[0005] Therefore, in order to ensure the technical effectiveness of the sealing cold air of the secondary air system in suppressing the high-temperature intrusion flow of the turbine, and on the basis of minimizing aerodynamic losses, it is necessary to design a turbine radial rim sealing structure with low sealing cold air demand and high sealing efficiency. This is of great theoretical and engineering significance for reducing the thermal stress on the turbine disk cavity, improving the service life of the turbine disk, and improving the overall efficiency of the turbine. Summary of the Invention

[0006] The technical objective of this invention is to address the specific characteristics of gas turbine turbines, the technical requirements for preventing turbine disc overheating, and the shortcomings of existing technologies by providing a turbine radial rim sealing structure that minimizes aerodynamic losses while achieving low sealing air requirements and high sealing efficiency, as well as a design method for this sealing structure.

[0007] The technical objective of this invention is achieved through the following technical solution: a turbine radial rim sealing structure, comprising a stationary disc as a stationary blade partition and a moving disc as a rotating disk. The stationary disc, used as the end to cooperate with the moving disc, has axially protruding stationary disc sealing teeth. The end of the stationary disc sealing teeth has a radially inwardly folded stationary tooth inner fold, and the cross-section of the inner fold of the stationary tooth has a rectangular structure. The movable disc, used as the end to cooperate with the stationary disc, has an axially protruding movable disc sealing tooth located radially inside the stationary disc sealing tooth. The end of the movable disc sealing tooth has a radially outwardly folded movable tooth outer fold, and the cross-section of the movable tooth outer fold has a rectangular structure. Furthermore, the outward fold of the moving tooth at the end of the moving disc sealing tooth and the inward fold of the stationary tooth at the end of the stationary disc sealing tooth form an interlocking fit relationship in the turbine axial direction, with an axial fit clearance between the two. The outward fold of the moving tooth and the inward fold of the stationary tooth have a radial overlap fit width in the turbine radial direction, so that the stationary disc and the moving disc form an axial labyrinth-type sealing structure, which can seal the cold air and prevent the high-temperature combustion gas from entering the turbine disc cavity.

[0008] Furthermore, there is an axial engagement distance between the end face of the stationary disk and the end face of the moving disk, and the value of the axial engagement distance is 25mm. Accordingly, the axial clearance between the stationary and moving teeth is 2 to 4 mm.

[0009] Furthermore, there is an axial engagement distance between the end face of the stationary disk and the end face of the moving disk, and the value of the axial engagement distance is 25mm. Accordingly, the radial overlap width of the stationary tooth-moving tooth is 2mm.

[0010] Furthermore, there is an axial engagement distance between the end face of the stationary disk and the end face of the moving disk, and the value of the axial engagement distance is 25mm. Correspondingly, the stationary tooth inner folded end of the stationary tooth sealing tooth and the moving tooth sealing tooth have a first radial fit clearance of stationary tooth-moving tooth forming a fluid channel in the turbine radial direction, and the value of the first radial fit clearance of stationary tooth-moving tooth is 2mm.

[0011] Furthermore, there is an axial fit clearance between the end of the stationary disc sealing tooth and the end face of the moving disc in the turbine axial direction, which forms a fluid channel. The value of the axial fit clearance between the stationary disc and the moving disc is 4mm.

[0012] Furthermore, there is an axial engagement distance between the end face of the stationary disk and the end face of the moving disk, and the value of the axial engagement distance is 25mm. Correspondingly, the moving tooth of the moving disc sealing tooth has a second radial fit clearance in the turbine radial direction between the outer folded end of the moving tooth and the stationary tooth, which constitutes a fluid passage. The value of the second radial fit clearance between the stationary tooth and the moving tooth is consistent with the value of the first radial fit clearance between the stationary tooth and the moving tooth.

[0013] Furthermore, the end of the moving disc sealing tooth and the end face of the stationary disc have an axial fit clearance in the turbine axial direction that forms a fluid channel, and the value of the axial fit clearance between the stationary disc and the moving disc is 2mm.

[0014] Furthermore, the movable tooth outer fold at the end of the movable disc sealing tooth has a radial outward fold height, which is 7mm.

[0015] Furthermore, the stationary disc sealing teeth are arranged by welding at the high radius position of the end face rim of the stationary disc, and are used to cooperate with the moving disc sealing teeth in an axial labyrinth-type sealing structure. And / or, the moving disc sealing teeth are arranged by welding at the high radius position of the end face rim of the moving disc, and are used to cooperate with the stationary disc sealing teeth in an axial labyrinth-type sealing structure.

[0016] A design method for the above-mentioned turbine radial rim seal structure, the design method comprising the following processes: S1. Select a certain type of radial rim seal gas turbine and obtain its geometric parameters; S2. Model using the obtained geometric parameters; The sealing structure at the radial rim of the turbine is designed according to the above-mentioned radial rim sealing structure of the turbine, so that an axial labyrinth-type sealing structure is formed at the radial rim of the turbine; wherein, the axial fit clearance between the stationary tooth and the moving tooth is set to any value within the range of 2 to 4 mm; Generate a 3D geometric model and a computational mesh; S3. Numerical simulation of the rim sealing performance and unsteady flow characteristics of the damping structure in the turbine disk cavity is performed. The time-averaged sealing efficiency, streamlines in the turbine disk cavity and sealing efficiency distribution characteristics at the measurement point are calculated to obtain the sealing performance response value. S4. Repeat S2 and S3 by adjusting different values ​​of the axial fit clearance between the stationary and moving teeth to obtain the sealing performance response value under different axial fit clearance conditions between the stationary and moving teeth; S5. By comparing different sealing performance response values, the optimal sealing efficiency of the monitoring point inside the turbine disk cavity is obtained, so as to determine the specific design value of the axial labyrinth seal structure of the turbine radial rim seal.

[0017] The beneficial technical effects of the present invention are as follows: The above-mentioned technical measures are designed for the special characteristics of the gas turbine turbine and the technical requirements for preventing overheating of the turbine disk. Under the premise of ensuring that the rotation of the turbine's stationary and moving disks is not affected by interference, the sealing tooth mating structure of the radial rim part between the stationary and moving disks is formed into a simple, reliable, and easy-to-manufacture specific axial labyrinth-type sealing structure. This increases the flow path of the main high-temperature turbine gas entering the turbine disk cavity while minimizing aerodynamic losses. This allows the sealing cold gas to be fully mixed with the invading gas in a reasonable multi-layer axial gap, thereby gradually dissipating the invading gas within the specific axial labyrinth-type sealing structure and preventing the invading gas from penetrating further into the turbine disk cavity.

[0018] The aforementioned specific axial labyrinth-type sealing structure formed at the radial rim of the turbine has a low requirement for sealing cold air, but high efficiency in blocking and dissipating intruding combustion gas, that is, high sealing efficiency for the turbine disk. It has significant technical significance and effect in reducing the thermal stress on the turbine disk cavity, improving the service life of the turbine disk and the overall efficiency of the turbine.

[0019] The aforementioned sealing parameters of the turbine radial rim sealing structure, under the premise of ensuring that the rotation of the turbine's moving and stationary discs is not affected by interference (i.e., during turbine operation, there will be no rubbing between the moving and stationary parts affected by centrifugal force and thermal deformation), not only reduce welding difficulty and assembly robustness, but also block the turbine's high-temperature intrusion flow with a lower sealing air requirement, reduce gas intrusion, and ensure the cooling effect of the secondary air system on the turbine disc, thus having the best sealing performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram (partial cross-section) of one structure of the present invention.

[0021] Figure 2 for Figure 1 A schematic diagram of the structure of the moving disk at the end.

[0022] Figure 3 for Figure 1 The structure shown is a frontal projection view at the cross-section.

[0023] Figure 4 for Figure 3 The diagram shows the fluid channel and the protection against high-temperature gas intrusion into the turbine disk cavity.

[0024] Figure 5 This is a flowchart of the design method of the present invention.

[0025] Meaning of the codes in the image: 1—Stationary disc; 11—Stationary blade; 12—Stationary disc sealing tooth; 13—Inner fold of the stationary tooth; 2—Moving disc; 21—Moving blade; 22—Moving disc sealing teeth; 23—Outer fold of the moving teeth; A—Axial fit clearance between stationary tooth and moving disc; B—Radial overlap fit width between stationary tooth and moving tooth; C—First radial fit clearance between stationary tooth and moving tooth; D—Axial fit clearance between stationary tooth and moving tooth; E—Second radial fit clearance between stationary tooth and moving tooth; F—Axial fit clearance between stationary disc and moving tooth; G—Radial outward bend height of moving tooth; H—Axial fit distance between wheel and disc. I—Direction of gas intrusion; O—Direction of cold air outflow; X—Turbine axial direction; Y—Turbine radial direction. Detailed Implementation

[0026] This invention relates to the field of gas turbine sealing technology, specifically a turbine radial rim sealing structure and a design method for this sealing structure. The following description is in conjunction with the accompanying drawings. Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The technical solution of this invention will be clearly and thoroughly explained.

[0027] It should be noted that the accompanying drawings of this invention are schematic, and unnecessary details have been simplified to clarify the technical objectives of this invention, so as to avoid obscuring the technical solutions contributed by this invention to the prior art. Furthermore, the terms "approximately" or "basically" used below to refer to quantities or fit relationships mean that reasonable assembly and processing errors are allowed in the industry, and do not literally describe absolute quantities or fit relationships.

[0028] See Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the present invention is a radial rim sealing structure for a gas turbine turbine, including a stationary disk 1 as a stationary blade partition and a rotating disk 2 as a rotating disk. Multiple stationary blades 11 are arranged on the outer periphery of the stationary disk 1, and multiple rotating blades 21 are arranged on the outer periphery of the rotating disk 2.

[0029] In this design, at the end of the stationary disc 1 that serves to mate with the moving disc 2, a stationary disc sealing tooth 12 is welded to the end face of the stationary disc 1 at the high radius position of the rim. This tooth serves to engage with the moving disc sealing tooth 22 in an axial labyrinth-type sealing structure. In other words, at the high radius position of the end wall of the stationary disc 1 that serves to mate with the moving disc 2, there is an axially outwardly protruding stationary disc sealing tooth 12. The end of this stationary disc sealing tooth 12 has a radially inwardly folded stationary tooth inner fold portion 13, and the cross-section of the stationary tooth inner fold portion 13 has a rectangular structure.

[0030] At the end of the moving disk 2 that mates with the stationary disk 1, a moving disk sealing tooth 22 is welded to the end face rim of the moving disk 2 at the high radius position, and is used to mate with the stationary disk sealing tooth 12 in an axial labyrinth-type sealing structure. That is, at the high radius position of the end wall of the moving disk 2 that mates with the stationary disk 1, there is an axially protruding moving disk sealing tooth 22 located radially inside the stationary disk sealing tooth 12. The end of the moving disk sealing tooth 22 has a radially outwardly folded moving tooth outer fold portion 23, and the cross-section of the moving tooth outer fold portion 23 is rectangular.

[0031] When the stationary disk 1 and the moving disk 2 are assembled, a radial rim sealing structure is formed between their mating end faces (including sealing teeth). At this time, the outward fold 23 of the moving tooth at the end of the moving disk sealing tooth 22 and the inward fold 13 of the stationary tooth at the end of the stationary disk sealing tooth 12 form an interlocking fit relationship in the turbine axial direction X. That is, the outward fold 23 of the moving tooth at the end of the moving disk sealing tooth 22 is embedded in the groove formed by the radial inward fold of the stationary tooth in the stationary disk sealing tooth 12 due to the inward fold of the stationary tooth in the inward fold. Similarly, the inward fold 13 of the stationary tooth at the end of the stationary disk sealing tooth 12 is embedded in the groove formed by the radial outward fold of the moving tooth outward fold 23 of the moving disk sealing tooth 21. This results in the interlocking fit relationship between the outward fold 23 of the moving tooth at the end of the moving disk sealing tooth 22 and the inward fold 13 of the stationary tooth at the end of the stationary disk sealing tooth 12 in the turbine axial direction X. This also results in the outward fold 23 of the moving tooth and the inward fold 13 of the stationary tooth having a radial overlap fit width B in the turbine radial direction Y.

[0032] The turbine radial rim sealing structure, which is formed by the interlocking and staggered engagement of the moving tooth outer fold 23 of the moving disc sealing tooth 22 and the stationary tooth inner fold 13 of the stationary disc sealing tooth 12 in the turbine axial direction X, requires the construction of a fluid channel.

[0033] The construction of this fluid channel is necessary to meet the technical requirement that the rotation of the turbine's moving and stationary discs be unaffected by interference, and to suppress the intrusion of the turbine's high-temperature main flow (i.e., intrusion flow / gas intrusion) with a low amount of sealing cold air.

[0034] Therefore, there is an axial engagement distance H between the end face of the stationary disk 1 and the end face of the moving disk 2, and the value of the axial engagement distance H is 25mm. Compatible with: The end of the stationary disc sealing tooth 12 (referring to the part near the end face of the moving disc 2) and the end face of the moving disc 2 have a stationary tooth-moving disc axial fitting clearance A in the turbine axial direction X, which constitutes a fluid passage. The value of the stationary tooth-moving disc axial fitting clearance A is 4mm. The stationary tooth inner fold 13 end of the stationary tooth of the stationary disc sealing tooth 12 (referring to the part close to the moving disc sealing tooth 21) and the moving disc sealing tooth 22 have a stationary tooth-moving tooth first radial fit clearance C in the turbine radial direction Y, which constitutes a fluid passage. The value of the stationary tooth-moving tooth first radial fit clearance C is 2mm. Between the interlocking outer folded portion 23 of the moving tooth and the inner folded portion 13 of the stationary tooth on the turbine axis X, there is an axial fit clearance D between the stationary tooth and the moving tooth. The value of the axial fit clearance D between the stationary tooth and the moving tooth is 2 to 4 mm (the specific value is determined according to the following design method). The end of the moving tooth outward fold 23 of the moving tooth of the moving disc sealing tooth 22 (referring to the part close to the stationary disc sealing tooth 12) and the stationary disc sealing tooth 12 have a second radial mating clearance E between the stationary tooth and the moving tooth in the turbine radial direction Y, which constitutes a fluid passage. The value of the second radial mating clearance E between the stationary tooth and the moving tooth is consistent with the value of the first radial mating clearance C between the stationary tooth and the moving tooth, that is, the value of the second radial mating clearance E between the stationary tooth and the moving tooth is 2mm. The end of the moving disc sealing tooth 22 (referring to the part near the end face of the stationary disc 1) and the end face of the stationary disc 1 have an axial mating clearance F between the stationary disc and the moving tooth in the turbine axial direction X, which constitutes a fluid passage. The value of the axial mating clearance F between the stationary disc and the moving tooth is 2mm.

[0035] Thus, based on the moving disk sealing teeth 22 and the outer fold of the moving teeth 23 on the end face of the moving disk 2, and the stationary disk sealing teeth 12 and the inner fold of the stationary teeth 13 on the end face of the stationary disk 1, an interlocking and staggered fit relationship is formed in the turbine axial direction X, constructing a fluid channel with the stationary tooth-moving disk axial fit clearance A, the stationary tooth-moving tooth first radial fit clearance C, the stationary tooth-moving tooth axial fit clearance D, the stationary tooth-moving tooth second radial fit clearance E, and the stationary disk-moving tooth axial fit clearance F connected in sequence. Based on the operating characteristics of the gas turbine, the outer end of the axial fit clearance A between the stationary gear and the moving disk serves as the inlet for the gas intrusion direction I, and the outer end of the axial fit clearance F between the stationary disk and the moving gear serves as the inlet for the cold gas outflow direction O. This allows the sealing cold gas to mix and dissipate the intruding gas in varying degrees of intensity within the axial fit clearances F, E, D, C, and A, with the main mixing occurring at the axial fit clearances D and C. Therefore, this invention enables the stationary disk 1 and the moving disk 2 to form an axial labyrinth-type sealing structure, creating a fluid channel capable of preventing the intrusion of high-temperature gas into the turbine disk cavity by sealing the cold gas.

[0036] While ensuring the above-mentioned technical requirements for preventing gas intrusion, in order to reduce welding difficulty and assembly robustness, the moving tooth outer fold 23 at the end of the moving disc sealing tooth 22 has a moving tooth radial outward fold height G (referring to the radial distance between the inner side of the moving disc sealing tooth 22 and the end of the moving tooth outer fold 23), and the value of the moving tooth radial outward fold height G is 7mm.

[0037] See Figure 5 As shown, the design method of the above-mentioned turbine radial rim seal structure includes the following processes: S1. Select a certain type of radial rim seal gas turbine and obtain its geometric parameters; These geometric parameters include key parameters such as the axial distance of the wheel, blade height, number of blades, and rim radius; S2. Model using the obtained geometric parameters; The sealing structure at the radial rim of the turbine is designed according to the above-mentioned radial rim sealing structure of the turbine, so that an axial labyrinth-type sealing structure is formed at the radial rim of the turbine. Among them, the axial fit clearance D between the stationary tooth and the moving tooth can be set to any value within the range of 2 to 4 mm, such as 2 mm / 3 mm / 4 mm, etc. Generate a 3D geometric model and a computational mesh; S3. Numerical simulation of the rim sealing performance and unsteady flow characteristics of the damping structure in the turbine disk cavity is performed. The time-averaged sealing efficiency, streamlines in the turbine disk cavity and sealing efficiency distribution characteristics at the measurement point are calculated to obtain the sealing performance response value. S4. Repeat S2 and S3 by adjusting different values ​​of the axial fit clearance D between the stationary and moving teeth to obtain the sealing performance response value under different axial fit clearance D states between the stationary and moving teeth; S5. By comparing different sealing performance response values, the optimal sealing efficiency of the monitoring point inside the turbine disk cavity is obtained, so as to determine the specific design value of the axial labyrinth seal structure of the turbine radial rim seal.

[0038] The turbine radial rim sealing structure formed by the above structure and design method enhances the sealing performance at the high radius position of the turbine radial rim, thereby relatively reducing the design technical requirements for the sealing structure at the low radius position of the turbine radial rim.

[0039] The above specific technical solutions are only used to illustrate the present invention, and are not intended to limit it.

[0040] Although the present invention has been described in detail with reference to the specific technical solutions described above, those skilled in the art should understand that modifications can still be made to the specific technical solutions described above, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A turbine radial rim sealing structure, comprising a stationary disc (1) as a stationary blade partition and a moving disc (2) as a rotating wheel disc. Its features are: The stationary disc (1) is used as the end of the moving disc (2) and has an axially protruding stationary disc sealing tooth (12). The end of the stationary disc sealing tooth (12) has a radially inwardly folded stationary tooth inner fold (13). The cross-section of the stationary tooth inner fold (13) is rectangular. The moving disk (2) is used to cooperate with the end of the stationary disk (1), and has an axially protruding moving disk sealing tooth (22) located on the radial inner side of the stationary disk sealing tooth (12). The end of the moving disk sealing tooth (22) has a radially outward folded moving tooth outer portion (23), and the cross-section of the moving tooth outer portion (23) is rectangular. Furthermore, the outward fold of the moving tooth (23) at the end of the moving disc sealing tooth (22) and the inward fold of the stationary tooth (13) at the end of the stationary disc sealing tooth (12) form an interlocking fit relationship in the turbine axial direction (X), and there is a stationary tooth-moving tooth axial fit clearance (D) between them. The outward fold of the moving tooth (23) and the inward fold of the stationary tooth (13) have a stationary tooth-moving tooth radial overlap fit width (B) in the turbine radial direction (Y), so that the stationary disc (1) and the moving disc (2) form an axial labyrinth-type sealing structure, which can seal the cold air and prevent the high-temperature combustion gas from entering the turbine disc cavity.

2. The turbine radial rim sealing structure according to claim 1, characterized in that: There is an axial engagement distance (H) between the end face of the stationary disk (1) and the end face of the moving disk (2), and the value of the axial engagement distance (H) is 25mm. Accordingly, the axial clearance (D) between the stationary and moving teeth is 2 to 4 mm.

3. The turbine radial rim sealing structure according to claim 1, characterized in that: There is an axial engagement distance (H) between the end face of the stationary disk (1) and the end face of the moving disk (2), and the value of the axial engagement distance (H) is 25mm. Accordingly, the radial overlap fit width (B) of the stationary tooth-moving tooth is 2mm.

4. The turbine radial rim sealing structure according to claim 1, characterized in that: There is an axial engagement distance (H) between the end face of the stationary disk (1) and the end face of the moving disk (2), and the value of the axial engagement distance (H) is 25mm. Correspondingly, the stationary tooth inner fold (13) end of the stationary tooth of the stationary disc sealing tooth (12) and the moving disc sealing tooth (22) have a first radial fit clearance (C) in the turbine radial direction (Y) to form a fluid channel, and the value of the first radial fit clearance (C) of the stationary tooth and the moving tooth is 2mm.

5. The turbine radial rim sealing structure according to claim 1 or 4, characterized in that: Between the end of the stationary disc sealing tooth (12) and the end face of the moving disc (2), there is a stationary tooth-moving disc axial fitting clearance (A) forming a fluid channel in the turbine axial direction (X), and the value of the stationary tooth-moving disc axial fitting clearance (A) is 4mm.

6. The turbine radial rim sealing structure according to claim 1, characterized in that: There is an axial engagement distance (H) between the end face of the stationary disk (1) and the end face of the moving disk (2), and the value of the axial engagement distance (H) is 25mm. Correspondingly, the end of the moving tooth outward fold (23) of the moving disc sealing tooth (22) and the stationary disc sealing tooth (12) have a stationary tooth-moving tooth second radial fit clearance (E) in the turbine radial direction (Y) to form a fluid passage. The value of the second radial fit clearance (E) between the stationary tooth and the moving tooth is consistent with the value of the first radial fit clearance (C) between the stationary tooth and the moving tooth.

7. The turbine radial rim sealing structure according to claim 1 or 6, characterized in that: The end of the moving disk sealing tooth (22) and the end face of the stationary disk (1) have a stationary disk-moving tooth axial fitting clearance (F) that forms a fluid channel in the turbine axial direction (X), and the value of the stationary disk-moving tooth axial fitting clearance (F) is 2mm.

8. The turbine radial rim sealing structure according to claim 1 or 6, characterized in that: The moving tooth outer fold (23) at the end of the moving disc sealing tooth (22) has a moving tooth radial outer fold height (G), and the value of the moving tooth radial outer fold height (G) is 7mm.

9. The turbine radial rim sealing structure according to claim 1, characterized in that: The stationary disc sealing teeth (12) are arranged by welding at the high radius position of the end face rim of the stationary disc (1) and are used to cooperate with the moving disc sealing teeth (22) in an axial labyrinth-type sealing structure. And / or, the moving disc sealing teeth (22) are arranged by welding at the high radius position of the end face rim of the moving disc (2) to cooperate with the stationary disc sealing teeth (12) in an axial labyrinth-type sealing structure.

10. A design method for a turbine radial rim sealing structure according to any one of claims 1 to 9, characterized in that, The design method includes the following processes: S1. Select a certain type of radial rim seal gas turbine and obtain its geometric parameters; S2. Model using the obtained geometric parameters; The sealing structure at the radial rim of the turbine is designed according to any one of claims 1 to 9, so that an axial labyrinth-type sealing structure is formed at the radial rim of the turbine; wherein the axial fit clearance (D) between the stationary tooth and the moving tooth is set to any value in the range of 2 to 4 mm; Generate a 3D geometric model and a computational mesh; S3. Numerical simulation of the rim sealing performance and unsteady flow characteristics of the damping structure in the turbine disk cavity is performed. The time-averaged sealing efficiency, streamlines in the turbine disk cavity and sealing efficiency distribution characteristics at the measurement point are calculated to obtain the sealing performance response value. S4. Repeat S2 and S3 by adjusting different values ​​of the axial fit clearance (D) between the stationary and moving teeth to obtain the sealing performance response values ​​under different axial fit clearance (D) conditions between the stationary and moving teeth; S5. By comparing different sealing performance response values, the optimal sealing efficiency of the monitoring point inside the turbine disk cavity is obtained, so as to determine the specific design value of the axial labyrinth seal structure of the turbine radial rim seal.

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