A gas turbine and its pre-rotation air supply system sealing structure and assembly method

Abstract

The application discloses a gas turbine and a sealing structure and an assembling method of a pre-rotation gas supply system of the gas turbine, which are used for realizing the sealing between a front cover plate disc and a turbine disc in a pre-rotation gas supply system of a turbine rotor of the gas turbine, and ensuring the effective cooling of the turbine rotor of the gas turbine under high-temperature and high-speed working conditions. The structure is characterized in that: the elastic deformation of a bent arm is caused by applying an initial pre-tightening force, the end surface sealing structure of the front cover plate disc is kept in close contact with the end surface of the turbine disc, and thus the cold gas leakage is effectively prevented. In addition, the sealing and pressing effect is further enhanced by the centrifugal force in the compact space through the simple and small pull ear structure, and the structural reliability is improved. The discrete hook design is adopted, and the limiting action is provided when the displacement tendency occurs between the turbine disc and the front cover plate disc, and the sealing gap is prevented from being enlarged. The application has the characteristics of convenient installation, strong deformation resistance and high stability, ensures the cooling efficiency of the gas turbine under severe working conditions, and prolongs the service life of the system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of gas turbine power plants, and relates to a sealing structure of a gas turbine turbine rotor cooling air supply system and an assembling technology thereof, in particular to a gas turbine and a sealing structure and an assembling method of a pre-swirl air supply system thereof, which are mainly applied to a pre-swirl air supply system of a turbine rotor of an aero-engine and an industrial gas turbine, and are used for guaranteeing the reliability of turbine rotor cooling air supply. BACKGROUND

[0002] An aero-engine and an industrial gas turbine are important power plants of military equipment, civil transportation and industrial power systems. With the improvement of engine performance, the temperature before the turbine of the gas turbine rises, and the hot end components such as turbine blades and turbine discs bear huge thermal load, which leads to a significant decrease in the service life of the turbine rotor and seriously affects the overall service life and reliability of the gas turbine. To solve this problem, advanced gas turbines, especially aero-engines, generally provide the turbine rotor with appropriate flow and pressure of cooling air through a pre-swirl air supply system, which significantly reduces the relative total temperature of the cooling air during the air supply process, so that the hot end components such as turbine blades and turbine discs are effectively protected by the cooling air. Therefore, the design of the pre-swirl air supply system is of great significance to the improvement of the service life of the turbine rotor and the overall performance of the gas turbine.

[0003] A typical pre-swirl air supply system mainly consists of a pre-swirl nozzle, a front cover plate disc with receiving holes and air supply holes on the turbine rotor and the like. The pre-swirl nozzle accelerates and deflects the airflow to reduce the relative total temperature of the cooling air. The cooling air cooled by the pre-swirl nozzle enters the turbine rotor through the receiving holes on the front cover plate disc and the air supply holes on the turbine rotor in turn. The design of the front cover plate disc is crucial to the effective supply of cooling air. On the one hand, the front cover plate disc is assembled on the turbine rotor and rotates with it, and the sealing between the front cover plate disc and the turbine disc is realized through the sealing ring structure on the end face of the front cover plate disc to prevent cooling air leakage. On the other hand, the front cover plate disc has two sealing structures of outer and inner grate teeth, which are used to prevent cooling air from leaking out of the gap between the static part with the pre-swirl nozzle and the rotating part with the front cover plate disc.

[0004] In the prior art, the pre-swirl nozzle of the gas turbine pre-swirl air supply system is often designed at a lower radius to avoid large leakage of cooling air along the way. The purpose is to lower the radius at which the outer and inner grate teeth of the front cover plate disc are located, to reduce the gap between the grate teeth and to realize effective sealing. Although this design has a significant sealing effect in the low radius area, it also causes the center of gravity and the fixed connection position of the front cover plate disc to be close to the low radius position. The end face sealing structure at the high radius position of the front cover plate disc is prone to disengagement under the action of the centrifugal force generated by high-speed rotation, resulting in end face sealing failure, and then leading to a large amount of cooling air leakage in the pre-swirl system, which seriously endangers the cooling effectiveness of the turbine rotor.

[0005] Currently, some large-size gas turbines (such as large industrial gas turbines and aero engines) can adjust the front cover plate disk to induce a tendency for the end-face sealing structure to move towards the turbine disk under centrifugal force, further pressing the end face and forming an effective seal. However, this disk adjustment method is mainly suitable for large-size turbine systems. For high-speed, compact small gas turbines, due to the limited turbine structure size, the front cover plate disk shape must strictly adapt to the space requirements of the turbine disk, making it difficult to improve the problem of end-face sealing structure detachment through large-area disk adjustment.

[0006] In summary, the existing front cover plate end face sealing structure in the gas turbine pre-swirl gas supply system exhibits a tendency to detach and fail under high temperature and high speed conditions. Therefore, further innovation in local structures and assembly methods is needed to ensure that the front cover plate end face sealing structure does not detach under high temperature and high speed operating conditions, preventing cold gas leakage and achieving a stable and efficient seal to ensure the effective supply of pre-swirl cold gas in high temperature and high speed environments. Summary of the Invention

[0007] (I) Purpose of the Invention

[0008] To address the problems in existing gas turbine pre-swirl gas supply systems, such as the tendency for the front cover plate disk end face sealing structure to detach during high-speed rotation, leading to sealing failure, cold air leakage, and reduced cooling efficiency, as well as the difficulty in improving sealing performance through large-area disk adjustments in compact turbine structures, this invention aims to provide a sealing structure and assembly method for a gas turbine and its pre-swirl gas supply system. By introducing an initial preload design and local structural optimization in the front cover plate disk end face sealing structure, the invention ensures that the sealing structure remains compressed under high-speed rotation and high centrifugal force. This structure, through an end face sealing design with elastic curved arms and an additional lug structure, creates an initial elastic preload during assembly of the front cover plate disk, and further enhances the sealing effect under operating conditions through centrifugal force. Through these technical means, this invention effectively improves the problem of front cover plate disk end face sealing detachment in compact gas turbine pre-swirl gas supply systems, significantly improving the reliability and service life of the gas turbine rotor cooling system.

[0009] (II) Technical Solution

[0010] To achieve the objective of this invention and solve its technical problems, the present invention adopts the following technical solution:

[0011] The first objective of this invention is to provide a sealing structure for a gas turbine pre-swirl gas supply system, used to achieve a seal between the front cover plate and the turbine disk in the gas turbine rotor pre-swirl gas supply system, ensuring effective cooling of the gas turbine rotor under high temperature and high speed conditions. The structure includes at least a front cover plate, a turbine disk, and a disc-shaped nozzle stationary component. Specifically:

[0012] The front cover plate is coaxially fixedly mounted on the turbine disk at its center and located axially upstream of it. The disc-shaped nozzle stationary component is fixedly mounted on the turbine guide and located axially upstream of the front cover plate. The space enclosed by the disc-shaped nozzle stationary component and the front cover plate forms a cold air pre-swirl chamber, which is used to pre-swirl and guide the cold air entering the turbine rotor. The space enclosed by the front cover plate and the turbine disk forms a cold air sealing chamber, which is used to isolate the cold air, prevent leakage, and ensure the transmission of cold air.

[0013] The front cover plate is integrally machined at its high radius position to form a radially inward and axially backward inclined bow-shaped arm structure. The end sealing face of the bow-shaped arm structure is provided with an annular sealing ring and is formed as an end face sealing structure that abuts against the front face of the turbine disk. Furthermore, multiple pull lug structures are evenly distributed circumferentially on the outer side of the bow-shaped arm structure. Each pull lug structure is used to elastically deform the bow-shaped arm structure with the aid of external force during assembly, generating a preload force that presses the end sealing face of the bow-shaped arm structure against the front face of the turbine disk. When the gas turbine is in operation, the centrifugal force generated by each pull lug structure further enhances the pressing effect between the sealing faces.

[0014] Furthermore, the front cover plate disc has a number of discrete hooks evenly distributed circumferentially near the radius of the rear end face of the front cover plate, and the turbine disc has a number of discrete hooks evenly distributed circumferentially near the radius of the front end face of the turbine disc. Each discrete hook of the front cover plate and the discrete hook of the turbine disc correspond one-to-one in the circumferential position and are engaged in a snap-fit ​​engagement in the assembled state to limit the axial displacement of the front cover plate and ensure a stable connection between the front cover plate and the turbine disc in the high-speed rotation state.

[0015] The second objective of this invention is to provide a gas turbine, characterized in that the gas turbine includes the aforementioned gas turbine pre-swirl gas supply system sealing structure.

[0016] The third objective of this invention is to provide an assembly method for the sealing structure of the above-mentioned gas turbine pre-swirl gas supply system, wherein the assembly method includes at least the following steps:

[0017] SS1. Preliminary positioning of the front cover plate and turbine disc

[0018] Interlock the keyway of the front cover plate with the keyway of the turbine disk, and push the front cover plate into the center hub of the turbine disk along the axial direction until the keyway of the front cover plate completely passes through the keyway of the turbine disk, ensuring that the two are aligned in the axial direction and coaxially positioned, and ensuring that there is an axial overlap between the discrete hooks of the front cover plate and the discrete hooks of the turbine disk.

[0019] SS2. Apply preload to create axial clearance.

[0020] Preload is applied at a preset position on the front end face of the bow-shaped bend arm structure of the front cover plate, causing the front cover plate to press down towards the turbine disk. This causes an axial gap to form between the discrete hooks of the front cover plate and the discrete hooks of the turbine disk under the action of elastic deformation. At the same time, the pull lugs on the end face sealing structure are pulled radially outward, so that the end sealing end face of the bow-shaped bend arm structure and the front end face of the turbine disk are temporarily disengaged, thus providing operating space for subsequent adjustments.

[0021] SS3. Angular position adjustment of the front cover plate

[0022] The clamping tool holds the clamping groove on the front end face of the front cover plate. While maintaining the axial clearance and the sealing end face is out of contact, the front cover plate is rotated until the angular positions of each discrete hook of the front cover plate and the discrete hook of the turbine disk are completely aligned, and the teeth on the keyway of the front cover plate and the keyway of the turbine disk correspond one-to-one, so that the front cover plate and the turbine disk achieve an ideal angular alignment. Then, the locking block is inserted into the aligned keyway of the front cover plate and the keyway of the turbine disk, and the locking block is fixed with a retaining ring to realize the torsional connection between the front cover plate and the turbine disk.

[0023] SS4. Release the preload and perform arm springback.

[0024] Withdraw the preload applied to the front cover plate and gradually release the pulling force on the pull lug structure, causing the bow-shaped arm structure to elastically rebound, thereby pushing the end sealing face of the bow-shaped arm structure to form a stable pressing contact with the front face of the turbine disk, realizing the initial pressing state of the sealing structure and ensuring the stability of the initial preload effect;

[0025] SS5. Assembly Inspection and Adjustment

[0026] After completing the above steps, perform a final assembly inspection to ensure the tightness of the keyway between the front cover plate and the turbine plate at the assembly mating surface, confirm that the bow-shaped arm structure is in a suitable pre-tightening deformation state, check the sealing effect of the sealing end face, ensure the unobstructed flow path of cold air, and make appropriate fine adjustments if necessary to ensure the stability and reliability of all components under actual operating conditions.

[0027] (III) Technical Effects

[0028] Compared with the prior art, the gas turbine and its pre-swirl gas supply system sealing structure and assembly method of the present invention have the following beneficial and significant technical effects:

[0029] (1) This invention employs an initial preload method. By designing an arched arm structure, an end-face sealing structure, discrete hooks, keyways, and other axially fitted dimensions on the front cover plate, the arched arm structure undergoes initial elastic deformation under the preload, causing the end face of the front cover plate to press against the turbine disk. This prestressed design not only ensures the sealing effect under static conditions but also provides a fundamental guarantee for the sealing performance under dynamic operating conditions, significantly improving the overall reliability of the system.

[0030] (2) The pull lug designed in this invention has a simple structure and small size, which helps to further press the sealing structure of the front cover plate disk end face towards the turbine disk through centrifugal force under the condition of limited space in the compact gas turbine structure, thereby increasing the structural reliability. This optimized design not only improves the reliability of the sealing structure, but also effectively utilizes the centrifugal force effect to avoid seal failure under high speed conditions, reduces the system's dependence on the initial preload, and provides a more stable working environment for the gas turbine.

[0031] (3) The hook structure adopted in this invention can hook the turbine disk when the sealing structure of the front cover plate end face tends to detach outward in the working state. This helps to limit further deformation of the front cover plate, prevent the sealing gap from expanding, and ensure that the sealing structure remains stable under high load and high temperature conditions. This avoids cold gas leakage caused by the increase in gap and ensures the normal operation of the gas turbine.

[0032] (4) The triple protection mechanism of this invention (pre-tightening force, centrifugal force pressurization, and hook limiting) forms a complete technical support system. The pre-tightening force provides basic sealing assurance, the centrifugal force achieves dynamic pressurization, and the hook structure ensures structural integrity under extreme working conditions. This multi-protection strategy significantly improves the reliability and safety of the sealing system and effectively reduces the risk of system failure. Attached Figure Description

[0033] Figure 1 This is an overall sectional view of the sealing structure of the gas turbine pre-swirl gas supply system of the present invention;

[0034] Figure 2 This is a schematic diagram of the cooling airflow path of the turbine rotor in the pre-swirl air supply system of the present invention. The arrows in the diagram represent the flow direction of the cooling gas.

[0035] Figure 3 This is a schematic diagram of the pre-tightening force realization method of the sealing structure on the upper end face of the front cover plate in this invention;

[0036] Figure 4This is a partially enlarged view of the end-face sealing structure in this invention;

[0037] Figure 5 This is an assembly flow diagram of the sealing structure of the gas turbine pre-swirl gas supply system of the present invention;

[0038] Explanation of reference numerals in the attached figures:

[0039] 1-Front cover plate, 11-Sealing end face structure, 11a-Arch-shaped curved arm structure, 11b-Pull ear structure, 12-Front cover plate discrete hook, 13-Clamping groove, 14-Front cover plate keyway, 15-Outer grate teeth, 16-Inner grate teeth, 17-Cold air receiving hole, 1a, 1b-Sealing end face on the rear end face of the front cover plate, 1c-Front end face at the mid-radius position of the front cover plate, 1d-Rear end face at the mid-radius position of the front cover plate, 1e-Front cover plate assembly mating surface, 2-Turbine disc, 21-Turbine disc front end face, 22-Turbine disc discrete hook, 23-Turbine disc hub, 24-Turbine disc keyway, 27-Cold air supply channel, 2a-Turbine disc inner diameter surface, 2b-Turbine disc outer diameter surface, 3-Disc-shaped nozzle stationary part, 37-Pre-rotating nozzle, 4-Locking block, 5-Retaining ring, 6-Sealing ring. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] Example 1

[0042] As a specific example, such as Figures 1 to 4As shown, the sealing structure of the gas turbine pre-swirl gas supply system of the present invention is used to achieve the sealing between the front cover plate and the turbine disk in the gas turbine rotor pre-swirl gas supply system, ensuring effective cooling of the gas turbine rotor under high temperature and high speed conditions. The structure mainly includes: front cover plate 1, turbine disk 2, disc-shaped nozzle stationary part 3, end face sealing structure 11, bow-shaped bent arm structure 11a, pull ear structure 11b, sealing end faces 1a and 1b on the rear end face of the front cover plate (wherein the sealing end face 1a is located outside the sealing ring 6, and the sealing end face 1b is located inside the sealing ring 6), sealing ring 6, front cover plate discrete hook 12, turbine disk discrete hook 22, clamping groove 13, front cover plate keyway 14, turbine disk keyway 24, locking block 4, retaining ring 5, outer grate teeth 15, inner grate teeth 16, pre-swirl nozzle 37, cold air receiving hole 17, cold air supply channel 27, etc.

[0043] The disc-shaped nozzle stationary component 3 is bolted to the turbine guide and is located axially upstream of the front cover plate 1. The front cover plate 1 and turbine disk 2 are integrally assembled, with the front cover plate 1 axially located upstream of the turbine disk 2. Both rotate together during engine operation. The space enclosed by the disc-shaped nozzle stationary component 3 and the front cover plate 1 forms a cold gas pre-swirl chamber, used for pre-swirl treatment and guidance of the cold gas entering the turbine rotor. The space enclosed by the front cover plate 1 and turbine disk 2 forms a cold gas sealing chamber, used to isolate the cold gas, prevent leakage, and ensure effective transmission of cooling gas. During operation, the cooling gas supplied to the turbine rotor by the pre-swirl system is drawn from the two airflows in the combustion chamber, passing sequentially through the pre-swirl nozzle 37 on the nozzle stationary component, the cold gas receiving hole 17 on the front cover plate 1, and the cold gas supply channel 27 on the turbine disk 2, before reaching the turbine rotor to achieve turbine rotor cooling. Figure 2 ).

[0044] Preferably, multiple pre-swirl nozzles 37 are evenly distributed circumferentially at the low radius position of the disc-shaped nozzle stationary component 3. These nozzles are used to accelerate and deflect the cooling airflow drawn from the two airflows in the combustion chamber into the cold air pre-swirl chamber and reduce its relative total temperature. Multiple cold air receiving holes 17 are evenly distributed circumferentially at the low radius position of the front cover plate 1, and each cold air receiving hole 17 corresponds axially to the air supply hole 27 on the turbine disk 2. These holes guide the cooling gas from the cold air pre-swirl chamber into the cold air sealing chamber. Multiple cold air supply channels 27 are evenly distributed circumferentially at the high radius position of the turbine disk 2, and each cold air supply channel 27 is located radially inside the upper end face sealing structure 11. These channels transport the pre-swirled and cooled cooling gas from the cold air sealing chamber to the cooling path of the turbine rotor. Through the above cold air path arrangement, the cooling airflow drawn from the two airflows in the combustion chamber, after undergoing pre-swirl, cooling, guidance, and sealing processes, can achieve sufficient cooling of the turbine rotor under high temperature and high speed conditions.

[0045] In the sealing structure of the gas turbine pre-swirl gas supply system of the present invention, the front cover plate 1 has outer grating teeth 15 and inner grating teeth 16. The outer grating teeth 15 are circumferentially disposed at the mid-radius position of the front end face of the front cover plate 1, and the inner grating teeth 16 are circumferentially disposed at the low-radius position of the front end face of the front cover plate 1. The outer grating teeth 15 are radially disposed on the outer side of each pre-swirl nozzle 37 and cold gas receiving hole 17, and the inner grating teeth 16 are radially disposed on the inner side of each pre-swirl nozzle 37 and cold gas receiving hole 17. This is to prevent the cooling gas, which is accelerated and cooled by the pre-swirl nozzles, from leaking out from the rotation-stationary gap formed between the nozzle stationary member 3 and the front cover plate 1. Furthermore, the design parameters of the outer grating teeth 15 and the inner grating teeth 16, including the number of teeth, tooth height, and tooth gap, are optimized according to the operating speed and temperature of the gas turbine to ensure a sealing effect without causing scraping.

[0046] In the sealing structure of the gas turbine pre-swirl gas supply system of the present invention, an end face sealing structure 11 is designed on the front cover plate 1, and a sealing ring 6 is installed thereon to prevent the turbine rotor cooling gas supplied by the pre-swirl system entering from the receiving hole 17 from leaking out between the front cover plate 1 and the turbine disk 2. Generally, since the high radius position of the turbine disk is often in a high temperature environment, the sealing ring 6 is made of high temperature alloy material, and its cross-sectional shape and size are optimized to maintain good elasticity and sealing performance under high temperature and high speed conditions.

[0047] In addition, the front cover plate 1 has keyways 14 evenly distributed around the center hole of the front cover plate 1, and multiple turbine disk keyways 24 are evenly distributed on the outer surface of the center hub of the turbine disk 2, which correspond one-to-one with the keyways 14 of the front cover plate 1. The keyways 14 of the front cover plate 1 and the keyways 24 of the turbine disk 2 are connected by wedge-shaped locking blocks 4. The wedge-shaped locking blocks 4 pass through the keyways 14 of the front cover plate 1 and the keyways 24 of the turbine disk 2. The retaining rings 5 ​​are used to restrict the wedge-shaped locking blocks 4 from coming out, so as to realize the transmission of torque between the front cover plate 1 and the turbine disk 2 when the aero engine is rotating and working, so that they rotate together.

[0048] Furthermore, to balance structural reliability and ease of assembly and disassembly, the number of wedge-shaped locking blocks 4 can be designed to be 2 to 4, evenly distributed around the circumference and inserted into the keyway 14 of the front cover plate and the keyway 24 of the turbine plate. The number of teeth and tooth width of the keyway 14 on the front cover plate 1 and the keyway 24 on the turbine plate 2 correspond, ensuring that after the front cover plate 1 is pushed in during assembly, the teeth on the keyway 14 and the keyway 24 correspond one-to-one, achieving axial positioning of the left end of the front cover plate 1.

[0049] In the sealing structure of the gas turbine pre-swirl gas supply system of the present invention, the method for achieving the pre-tightening force of the sealing structure 11 on the upper end face of the front cover plate 1 is as follows: Figure 3 , Figure 4 :

[0050] The end face sealing structure 11 is designed with an arc-shaped curved arm structure 11a. The arc-shaped curved arm structure 11a is formed by the profile at the high radius position of the front cover plate 1 through radial inclination and axial backward inclination. An annular sealing ring 6 is provided between the end sealing faces 1a and 1b of the arc-shaped curved arm structure 11a and abuts against the front end face 21 of the turbine disk. The curved structure of the arc-shaped curved arm structure 11a can generate elastic deformation during assembly, thereby generating a preload force to achieve the pressing between the sealing faces 1a and 1b and the end face of the turbine disk 2. Furthermore, the end face sealing structure 11 is designed with a pull lug structure 11b. Its function is, on the one hand, to use tooling hooks to hold the arc-shaped curved arm structure 11a during assembly, so that the arc-shaped curved arm structure 11a can elastically deform and generate a preload force; on the other hand, this local structure can be subjected to centrifugal force when the gas turbine is in operation, providing a pressing bending moment towards the turbine disk 2 to the end face sealing structure 11, so that the sealing faces 1a and 1b are further pressed between the front end face 21 of the turbine disk. Furthermore, a number of discrete hooks 12 are evenly distributed around the radius of the rear end face of the front cover plate 1, and a number of discrete hooks 22 are evenly distributed around the radius of the front end face of the turbine disk 2. Each discrete hook 12 of the front cover plate and the discrete hook 22 of the turbine disk are circumferentially aligned and engaged in the assembly state to limit the axial displacement of the front cover plate 1 and ensure a stable connection between the front cover plate 1 and the turbine disk 2 under high-speed rotation.

[0051] Preferably, a high-strength bolt connection to the front cover plate 1 and the turbine disk 2 can also be adopted. Multiple sets of bolt connection pairs are evenly distributed along the circumference on the mating end faces of the two. Each set of connection pairs includes a through hole through the front cover plate 1 and an internal threaded hole on the turbine disk 2. The bolt preload is used to achieve a stable connection between the front cover plate 1 and the turbine disk 2, ensuring that there will be no relative slippage or loosening under high temperature, high speed and high load conditions.

[0052] Preferably, the axial limit between the front cover plate 1 and the turbine disk 2 at the left end can also be achieved by using a nut and a central tie rod for clamping. One end of the central tie rod is connected to the central hub of the turbine disk 2 through a spline structure and is positioned by a locating pin. The other end extends out of the end face of the front cover plate 1 and is provided with an external thread. During the installation process, the front cover plate 1 is firmly fixed to the turbine disk 2 by the preload generated by tightening the nut, thereby effectively preventing axial displacement.

[0053] Preferably, in the end sealing faces 1a and 1b of the bow-shaped curved arm structure, the end face portion 1a located outside the annular sealing ring and the end face portion 1b located inside the sealing ring are designed to be non-coplanar. Through the design of the axial dimensions and tolerances of the structure, the end face portion 1a located outside the sealing ring 6 is made closer to the corresponding end face of the turbine disk 2, which helps to further prevent the end face sealing structure 11 from detaching and causing gap leakage.

[0054] Preferably, the front cover plate 1 is made of the same high-temperature alloy material as the turbine plate 2, and its plate thickness is less than that of the turbine plate. This makes the deformation of the front cover plate 1 greater than that of the turbine plate 2 in the working state, which helps to form a tighter assembly relationship between the two and further enhances the sealing effect.

[0055] Preferably, the clamping preload generated by the elastic deformation of the bow-shaped bending arm structure 11a during assembly should be selected to ensure that it is sufficient to pull the bow-shaped bending arm structure 11a to generate sufficient axial clearance between the discrete hooks 12 of the front cover plate and the discrete hooks 22 of the turbine disk after deformation, so as to facilitate the subsequent rotation of the front cover plate 1.

[0056] Example 2

[0057] Based on the gas turbine pre-swirl gas supply system sealing structure provided in Embodiment 1 above, Embodiment 2 further provides an assembly method for this sealing structure. Figure 5 This is a flowchart illustrating the assembly process of the sealing structure of the gas turbine pre-swirl gas supply system of the present invention. The specific assembly process is as follows:

[0058] SS1. Preliminary positioning of the front cover plate and turbine disc

[0059] First, the keyway 14 of the front cover plate is inserted into the keyway 24 of the turbine plate. The front cover plate 1 is pushed into the center hub of the turbine plate 2 along the axial direction to ensure that the two are aligned in the axial direction and coaxially positioned. When the keyway 14 of the cover plate is completely through the keyway 24 of the turbine plate, the discrete hook 12 of the front cover plate and the discrete hook 22 of the turbine plate are still axially overlapped at the rear end face 1d of the radius position of the front cover plate.

[0060] SS2. Apply preload to create axial clearance.

[0061] Furthermore, a preload is applied at the front face 1c of the front cover plate at the radius position, pressing it downwards towards the turbine disk. At this time, an axial gap is formed between the discrete hooks 12 of the front cover plate and the discrete hooks 22 of the turbine disk due to elastic deformation. The size of this gap should be controlled within the design specifications. At the same time, the pull lug structure 11b is pulled outwards to temporarily separate the sealing end faces 1a and 1b from the front face 21 of the turbine disk, thereby providing operating space for subsequent adjustments.

[0062] SS3. Angular position adjustment of the front cover plate

[0063] Since there is an axial gap between the discrete hook 12 of the front cover plate and the discrete hook 22 of the turbine disk, and there is also an axial gap between the sealing end face 1a and the sealing end face 1b and the turbine disk 2, the front cover plate 1 can be rotated by clamping the clamping groove 13 provided on the front end face of the front cover plate 1, so that the discrete hook 12 of the front cover plate and the discrete hook 22 of the turbine disk are in an angularly aligned relationship. At the same time, the teeth on the keyway 14 of the front cover plate and the keyway 24 of the turbine disk are also in a one-to-one correspondence, so that the front cover plate 1 and the turbine disk 2 are in an angularly aligned state. Then, the locking block 4 is inserted into the aligned keyway 14 of the front cover plate and the keyway 24 of the turbine disk, and the locking block 4 is fixed with the retaining ring 5 to realize a reliable torque transmission connection between the front cover plate 1 and the turbine disk 2.

[0064] SS4. Release the preload and perform arm springback.

[0065] The preload applied to the front cover plate 1 is withdrawn, and the pull lug structure 11b is gradually loosened, releasing the applied tension. The bow-shaped arm structure 11a springs back, causing the end sealing faces 1a and 1b of the bow-shaped arm structure 11a to be pressed against the front face 21 of the turbine disk 2. Corresponding teeth of the keyway 14 of the front cover plate and the keyway 24 of the turbine disk are also pressed against each other at the mating surface 1e. Thus, with the arm 11a undergoing initial elastic deformation, the front cover plate 1 is pressed against the turbine disk 2 with an initial preload. This initial preload ensures the stability of the sealing structure, preventing loosening or deformation caused by dynamic loads during operation.

[0066] SS5. Assembly Inspection and Adjustment

[0067] After completing the above steps, perform a final assembly inspection to ensure the pressing relationship between the front cover plate keyway 14 and the turbine plate keyway 24 at the assembly mating surface 1e, confirm that the bow-shaped curved arm structure 11a is in a suitable pre-tightening deformation state, check the sealing effect of the sealing end face, ensure the unobstructed flow path of cold air, and make appropriate fine adjustments if necessary to ensure the stability and reliability of all components under actual operating conditions.

[0068] The above assembly method effectively ensures that the sealing structure of the gas turbine pre-swirl gas supply system of this invention achieves the desired assembly effect, guaranteeing its stability and reliability under high temperature and high pressure environments. This assembly method is simple to operate, highly reliable, and particularly suitable for widespread application in engineering practice.

[0069] The objectives of the present invention have been fully and effectively achieved through the above embodiments. Although the present invention has been described with respect to what is currently considered the most practical and preferred embodiments, it should be understood that the present invention is not limited to the disclosed embodiments, and any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A sealing structure for a pre-swirl air supply system of an aero-engine, comprising at least a front cover plate, a turbine disk, and a disc-shaped nozzle stationary component, characterized in that: The front cover plate is coaxially fixedly mounted on the turbine disk at its center and located upstream of it in the axial direction. The disc-shaped nozzle stationary component is fixedly mounted on the turbine guide and located upstream of the front cover plate in the axial direction. The space enclosed by the disc-shaped nozzle stationary component and the front cover plate forms a cold air pre-swirl chamber. The space enclosed by the front cover plate and the turbine disk forms a cold air sealing chamber. The front cover plate is integrally machined at its high radius position to form a radially inward and axially backward inclined bow-shaped arm structure. The end sealing face of the bow-shaped arm structure is provided with an annular sealing ring and is formed as an end face sealing structure that abuts against the front face of the turbine disk. Furthermore, multiple pull lug structures are evenly distributed circumferentially on the outer side of the bow-shaped arm structure. Each pull lug structure is used to elastically deform the bow-shaped arm structure with the aid of external force during assembly, generating a preload force that presses the end sealing face of the bow-shaped arm structure against the front face of the turbine disk. When the aero-engine is in operation, the centrifugal force generated by each pull lug structure further enhances the pressing effect between the sealing faces. Furthermore, the front cover plate disc has a number of discrete hooks evenly distributed around the radius of the rear end face of the front cover plate, and the turbine disk disc has a number of discrete hooks evenly distributed around the radius of the front end face of the turbine disk. Each discrete hook of the front cover plate and the discrete hook of the turbine disk correspond to each other in the circumferential position and are engaged in a snap-fit ​​engagement in the assembled state to limit the axial displacement of the front cover plate and ensure a stable connection between the front cover plate and the turbine disk in the high-speed rotation state. Multiple pre-swirl nozzles are evenly distributed circumferentially at the low radius position of the stationary disc-shaped nozzle component. These nozzles are used to accelerate and deflect the cooling airflow drawn from the two airflows in the combustion chamber into the cold air pre-swirl chamber and reduce its relative total temperature. Multiple cold air receiving holes are evenly distributed circumferentially at the low radius position of the front cover plate, and each of these cold air receiving holes corresponds axially to the air supply holes on the turbine disc. These holes are used to guide the cooling gas from the cold air pre-swirl chamber into the cold air sealing chamber. Multiple cold air supply channels are evenly distributed circumferentially at the high radius position of the turbine disc, and each of these channels is located radially inside the upper end face sealing structure. These channels are used to transport the pre-swirled and cooled cooling gas from the cold air sealing chamber to the cooling path of the turbine rotor.

2. The sealing structure of the pre-swirl air supply system for an aero-engine according to claim 1, characterized in that, The front cover plate has outer grating teeth at the mid-radius position and inner grating teeth at the low-radius position. The outer grating teeth are radially arranged on the outside of each pre-rotating nozzle and cold air receiving hole, and the inner grating teeth are radially arranged on the inside of each pre-rotating nozzle and cold air receiving hole, to prevent cooling gas from leaking from the stationary gap between the disc-shaped nozzle and the front cover plate.

3. The sealing structure of the pre-swirl air supply system for an aero-engine according to claim 1, characterized in that, Multiple keyways are evenly distributed circumferentially in the central hole of the front cover plate. Multiple turbine disk keyways, corresponding one-to-one with the keyways of the front cover plate, are evenly distributed on the outer surface of the central hub of the turbine disk. The keyways of the front cover plate and the keyways of the turbine disk are connected to each other by wedge-shaped locking blocks. A retaining ring is provided at the connection to restrict the wedge-shaped locking blocks from disengaging, thereby achieving a stable torque transmission connection between the front cover plate and the turbine disk.

4. The sealing structure of the aero-engine pre-swirl air supply system according to claim 3, characterized in that, The number and width of the teeth in the keyway of the front cover plate and the keyway of the turbine plate are related to the number and distribution of the discrete hooks of the front cover plate and the discrete hooks of the turbine plate, so that when each keyway of the front cover plate and the keyway of the turbine plate are in a one-to-one angular correspondence, each discrete hook of the front cover plate and the discrete hook of the turbine plate are also in an angularly facing relationship.

5. The sealing structure of the aero-engine pre-swirl air supply system according to claim 1, characterized in that, The front cover plate and the turbine plate are connected by a high-strength bolt to a torsion transmission structure. Multiple sets of bolt connection pairs are evenly distributed circumferentially on the mating end faces of the two. Each set of connection pairs includes a through hole penetrating the front cover plate and an internal threaded hole on the turbine plate. The front cover plate and the turbine plate are stably connected by the bolt preload.

6. The sealing structure of the pre-swirl air supply system for an aero-engine according to claim 1, characterized in that, The axial positioning between the front cover plate and the turbine disk at the left end is achieved by a nut and a central tie rod. One end of the central tie rod is connected to the central hub of the turbine disk through a spline structure and is positioned by a locating pin. The other end extends out of the end face of the front cover plate and is provided with an external thread. During installation, the front cover plate is firmly fixed to the turbine disk by the preload generated by tightening the nut.

7. The sealing structure of the pre-swirl air supply system for an aero-engine according to claim 1, characterized in that, In the end sealing face of the bow-shaped curved arm structure, the end face portion located outside the annular sealing ring and the end face portion located inside the annular sealing ring are designed to be non-coplanar. Through the design of the axial dimensions and tolerances of the structure, the end face portion located outside the annular sealing ring is made closer to the corresponding end face of the turbine disk, so as to further prevent the end face sealing structure from detaching and causing gap leakage.

8. The sealing structure of the pre-swirl air supply system for an aero-engine according to claim 1, characterized in that, The front cover plate is made of the same high-temperature alloy material as the turbine plate, and its thickness is less than that of the turbine plate. This makes the deformation of the front cover plate greater than that of the turbine plate in operation, so as to form a tighter assembly relationship between the two and further enhance the sealing effect.

9. The sealing structure of the pre-swirl air supply system for an aero-engine according to claim 1, characterized in that, The clamping preload generated by the elastic deformation of the bow-shaped arm structure during assembly should be selected to ensure that it is sufficient to pull the bow-shaped arm structure to generate sufficient axial clearance between the discrete hooks of the front cover plate and the discrete hooks of the turbine disk after deformation, so as to facilitate the subsequent rotation of the front cover plate.

10. An aircraft engine, characterized in that, The aero-engine includes the sealing structure of the aero-engine pre-swirl air supply system as described in any one of claims 1 to 9.

11. A method for assembling the sealing structure of the pre-swirl air supply system of an aero-engine as described in claim 4, characterized in that, The assembly method includes at least the following steps: SS1. Preliminary positioning of the front cover plate and turbine plate Interlock the keyway of the front cover plate with the keyway of the turbine disk, and push the front cover plate into the center hub of the turbine disk along the axial direction until the keyway of the front cover plate completely passes through the keyway of the turbine disk, ensuring that the two are aligned in the axial direction and coaxially positioned, and ensuring that there is an axial overlap between the discrete hooks of the front cover plate and the discrete hooks of the turbine disk. SS2. Apply preload to create axial clearance. Preload is applied at a preset position on the front end face of the bow-shaped bend arm structure of the front cover plate, causing the front cover plate to press down towards the turbine disk. This causes an axial gap to form between the discrete hooks of the front cover plate and the discrete hooks of the turbine disk under the action of elastic deformation. At the same time, the pull lugs on the end face sealing structure are pulled radially outward, so that the end sealing end face of the bow-shaped bend arm structure and the front end face of the turbine disk are temporarily disengaged, thus providing operating space for subsequent adjustments. SS3. Angular position adjustment of the front cover plate The clamping tool holds the clamping groove on the front end face of the front cover plate. While maintaining the axial clearance and the sealing end face is out of contact, the front cover plate is rotated until the angular positions of each discrete hook of the front cover plate and the discrete hook of the turbine disk are completely aligned, and the teeth on the keyway of the front cover plate and the keyway of the turbine disk correspond one-to-one, so that the front cover plate and the turbine disk achieve an ideal angular alignment. Then, the locking block is inserted into the aligned keyway of the front cover plate and the keyway of the turbine disk, and the locking block is fixed with a retaining ring to realize the torsional connection between the front cover plate and the turbine disk. SS4. Release the preload and perform arm springback. Withdraw the preload applied to the front cover plate and gradually release the pulling force on the pull lug structure, causing the bow-shaped arm structure to elastically rebound, thereby pushing the end sealing face of the bow-shaped arm structure to form a stable pressing contact with the front face of the turbine disk, realizing the initial pressing state of the sealing structure and ensuring the stability of the initial preload effect; SS5. Assembly Inspection and Adjustment After completing the above steps, perform a final assembly inspection to ensure the tightness of the keyway between the front cover plate and the turbine plate at the assembly mating surface, confirm that the bow-shaped arm structure is in a suitable pre-tightening deformation state, check the sealing effect of the sealing end face, ensure the unobstructed flow path of cold air, and make appropriate fine adjustments if necessary to ensure the stability and reliability of all components under actual operating conditions.

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