Gas turbine as well as sealing structure and assembling method of pre-whirl gas supply system of gas turbine

Abstract

The invention discloses a gas turbine as well as a sealing structure and an assembling method of a prewhirl gas supply system thereof, which are used for realizing the sealing between a front cover plate disc and a turbine disc in the prewhirl 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. According to the structure, the bent arm is elastically deformed by applying initial pre-tightening force, so that the front cover plate disc end face sealing structure is in close contact with the turbine disc end face, and cold air leakage is effectively prevented. In addition, through the pull lug structure which is simple in design and small in size, the sealing and pressing effect is further enhanced through centrifugal force in a compact space, and the structural reliability is improved. The design of discrete hooks is further adopted, the limiting effect can be provided when the displacement trend occurs between the turbine disc and the front cover plate disc, and the sealing gap is prevented from being enlarged. The device has the advantages of being convenient to install, high in deformation resistance and high in stability, the cooling efficiency of the gas turbine under the severe working condition is guaranteed, and the service life of a system is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas turbine power plants, and relates to a sealing structure and assembly technology of a gas turbine turbine rotor cooling air supply system, and specifically to a gas turbine and a sealing structure and assembly method of a pre-swirl air supply system thereof, which are mainly used in the turbine rotor pre-swirl air supply system of aircraft engines and industrial gas turbines to ensure the reliability of the cooling air supply to the turbine rotor. Background Art

[0002] Aircraft engines and industrial gas turbines are important power units for military equipment, civil transportation and industrial power systems. As engine performance improves, the temperature before the turbine of the gas turbine rises, and the hot end components such as turbine blades and turbine disks are subjected to huge heat loads, resulting in a significant decrease in the life of the turbine rotor, which seriously affects the overall life and reliability of the gas turbine. To solve this problem, advanced gas turbines, especially aircraft engines, generally use a pre-swirl air supply system to provide the turbine rotor with cold air of appropriate flow and pressure, which significantly reduces the relative total temperature of the cold air during the air supply process, so that the hot end components such as turbine blades and turbine disks are effectively protected by cold air. Therefore, the design of the pre-swirl air supply system is of great significance to improving the service life of the turbine rotor and the overall performance of the gas turbine.

[0003] A typical pre-swirl air supply system is mainly composed of a pre-swirl nozzle, a front cover plate with a receiving hole, and an air supply hole on the turbine rotor. The pre-swirl nozzle accelerates and deflects the airflow to reduce the relative total temperature of the cold air. The cold air cooled by the pre-swirl nozzle enters the turbine rotor through the receiving hole on the front cover plate and the air supply hole on the turbine rotor. Among them, the design of the front cover plate is crucial to the effective supply of cold air: on the one hand, the front cover plate is assembled on the turbine rotor and rotates with it, and the sealing ring structure on its end face is used to achieve sealing with the turbine disk to prevent cold air leakage; on the other hand, the front cover plate has two sealing structures, the outer comb teeth and the inner comb teeth, which are used to prevent cold air from leaking out from the gap between the stationary part with the pre-swirl nozzle and the rotor part where the front cover plate is located.

[0004] In the prior art, in order to avoid the problem of large leakage of cold air along the gas turbine pre-swirl air supply system, the pre-swirl nozzle is often designed at a lower radius, the purpose of which is to lower the radius of the outer and inner comb teeth on the front cover plate, reduce the comb tooth gap, and achieve effective sealing. Although this design has a significant sealing effect in the low radius area, it also causes the structural center of gravity and fixed connection position of the front cover plate to be close to the low radius position, and the end face sealing structure at the high radius position of the front cover plate is prone to disengagement under the centrifugal force generated by high-speed rotation, causing end face sealing failure, which in turn causes a large amount of cold air leakage in the pre-swirl system, seriously endangering the cooling effectiveness of the turbine rotor.

[0005] At present, the front cover plate of some large-sized gas turbines (such as large industrial gas turbines and aircraft engines) can adjust the disc shape to achieve the end face sealing structure to produce a movement trend towards the turbine disc under the action of centrifugal force, further compress the end face and form an effective seal. However, this disc shape adjustment method is mainly suitable for large-sized turbine systems. For high-speed, compact small gas turbines, due to the limited size of their turbine structure, the front cover plate disc shape must strictly adapt to the space requirements of the turbine disc, and it is difficult to improve the problem of end face sealing structure disengagement through large-area disc shape adjustment.

[0006] In summary, the front cover plate end face sealing structure in the existing gas turbine pre-swirl air supply system is prone to disengagement and sealing failure under high temperature and high speed conditions. Therefore, it is necessary to further innovate the local structure and assembly method to ensure that the front cover plate end face sealing structure does not disengage under high temperature and high speed working conditions, prevent cold air leakage, and achieve stable and efficient sealing to ensure the effective supply of pre-swirl cold air under high temperature and high speed environment. Summary of the invention

[0007] (I) Purpose of the invention

[0008] In view of the existing gas turbine cold air pre-swirl air supply system, the front cover plate disc end face sealing structure is prone to disengagement during high-speed rotation, resulting in sealing failure, which in turn causes cold air leakage and reduced cooling efficiency, and the compact turbine structure is difficult to improve the sealing performance through large-area disc adjustment. In order to solve at least one of the above and other technical problems in the prior art, the present invention aims to provide a gas turbine and its pre-swirl air supply system sealing structure and assembly method, by introducing an initial preload design and local structural optimization in the front cover plate disc end face sealing structure to ensure that the sealing structure remains in a compressed state under high-speed rotation and high centrifugal force. The structure forms an initial elastic preload during assembly of the front cover plate disc through an end face sealing design with an elastic bent arm and an additional pull ear structure, and further enhances the sealing effect under the action of centrifugal force in the working state. Through the above technical means, the present invention effectively improves the problem of the front cover plate disc end face seal disengagement in the compact gas turbine cold air pre-swirl system, and significantly improves the reliability and service life of the gas turbine rotor cooling system.

[0009] (II) Technical solution

[0010] In order to achieve the purpose of the invention and solve the technical problems, the present invention adopts the following technical solutions:

[0011] The first invention object of the present invention is to provide a gas turbine pre-swirl air supply system sealing structure, which is used to achieve the sealing between the front cover plate and the turbine disk in the pre-swirl air supply system of the gas turbine turbine rotor, and ensure the effective cooling of the gas turbine turbine rotor under high temperature and high speed conditions, and at least comprises a front cover plate, a turbine disk and a disc-shaped nozzle stationary part, specifically:

[0012] The center of the front cover plate is coaxially fixedly mounted on the turbine disk and is axially located on the upstream side thereof; the disc-shaped nozzle stationary member is fixedly mounted on the turbine guide and is axially located on the upstream side of the front cover plate; the space enclosed by the disc-shaped nozzle stationary member and the front cover plate forms a cold air pre-swirl chamber for pre-swirl treatment and flow guidance of 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 for isolating the cold air, avoiding leakage and ensuring the transmission of the cold air;

[0013] The profile at the high radius position of the front cover plate is integrally processed to form a radially inwardly inclined and axially backwardly inclined arcuate arm structure, the end sealing end face of the arcuate arm structure is provided with an annular sealing ring and forms an end face sealing structure abutting against the front end face of the turbine disk, and the outer side of the arcuate arm structure is evenly provided with a plurality of pull ear structures along the circumferential direction, each of the pull ear structures is used to elastically deform the arcuate arm structure with the aid of external force during assembly, so as to generate a pre-tightening force that causes the end sealing end face of the arcuate arm structure to press and abut against the front end face of the turbine disk, and the centrifugal force generated by each of the pull ear structures further enhances the pressing effect between the sealing end faces when the gas turbine is in a working state;

[0014] And wherein, a plurality of front cover plate discrete hooks are evenly distributed along the circumferential direction near the radial position in the rear end surface of the front cover plate, and a plurality of turbine disk discrete hooks are evenly distributed along the circumferential direction near the radial position in the front end surface of the turbine disk. Each of the front cover plate discrete hooks corresponds to the turbine disk discrete hooks one by one in the circumferential position and is snap-fitted 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 under high-speed rotation.

[0015] A second object of the present invention is to provide a gas turbine, characterized in that the gas turbine includes the above-mentioned gas turbine pre-swirl air supply system sealing structure.

[0016] The third object of the present invention is to provide a method for assembling the sealing structure of the pre-swirl air supply system of the gas turbine, wherein the assembly method comprises at least the following steps when implemented:

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

[0018] Insert the keyway of the front cover plate into 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 hook of the front cover plate and the discrete hook of the turbine disk;

[0019] SS2. Apply preload to create axial clearance

[0020] A pre-tightening force is applied at a preset position on the front end face of the bow-shaped curved arm structure of the front cover plate, so that the front cover plate is pressed downward toward the turbine disk, so that an axial gap is formed between the discrete hook of the front cover plate and the discrete hook of the turbine disk under the action of elastic deformation, and at the same time, the pull ear on the end face sealing structure is pulled radially outward, so that the end sealing end face of the bow-shaped curved arm structure and the front end face of the turbine disk are temporarily out of contact, thereby providing operating space for subsequent adjustments;

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

[0022] The clamping groove provided on the front end surface of the front cover plate is clamped by a clamping tool, and the front cover plate is rotated while maintaining the axial gap and the sealing end surface being out of contact, until the angular positions of the discrete hooks of the front cover plate and the discrete hooks 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 by one, so that the front cover plate and the turbine disk reach an ideal angular alignment state, and 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 torque transmission connection between the front cover plate and the turbine disk;

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

[0024] The preload force applied to the front cover plate is withdrawn, and the pulling force on the pull ear structure is gradually released, so that the bow-shaped curved arm structure rebounds elastically, thereby pushing the end sealing end face of the bow-shaped curved arm structure to form a stable compression contact with the front end face of the turbine disc, thus achieving the initial compression 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, carry out the final assembly inspection to ensure the compression relationship between the keyway of the front cover plate and the keyway of the turbine plate at the assembly joint surface, confirm that the bow-shaped bent arm structure is in a suitable pre-tightened deformation state, check the sealing effect of the sealing end face, ensure the smooth flow of the cold air flow path, and make appropriate fine adjustments when necessary to ensure the stability and reliability of all components under actual operating conditions.

[0027] (III) Technical Effect

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

[0029] (1) The present invention adopts the method of applying initial preload force, and by arranging the bow-shaped arm structure and the end face sealing structure, discrete hooks, key slots and other axial matching dimensions on the front cover plate, the bow-shaped arm structure generates initial elastic deformation under the preload force, and the end face of the front cover plate presses the turbine disc. This prestressed design not only ensures the sealing effect under static conditions, but also provides a basic guarantee for the sealing performance under dynamic conditions, significantly improving the overall reliability of the system.

[0030] (2) The pull ear designed in the present invention has a simple structure and a small size, which helps to further press the front cover plate disc end face sealing structure toward the turbine disc through the centrifugal force under the condition of limited space of 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 under high speed conditions to avoid sealing failure, 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 the present invention can hook the turbine disk when the front cover plate disk end face sealing structure tends to disengage outward in the working state, which helps to limit the further deformation of the front cover plate disk and prevent the expansion of the sealing gap. It ensures that the sealing structure always remains stable under high load and high temperature conditions, avoids cold air leakage caused by the increase of the gap, and ensures the normal operation of the gas turbine.

[0032] (4) The triple protection mechanism of the present invention (preload, centrifugal force boost, and hook limit) forms a complete technical support system. The preload provides basic sealing guarantee, the centrifugal force achieves dynamic boost effect, and the hook structure ensures structural integrity under extreme working conditions. This multiple protection strategy significantly improves the reliability and safety of the sealing system and effectively reduces the risk of system failure. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 2 Schematic diagram of the cooling airflow path of the turbine rotor in the pre-swirl air supply system of the present invention, wherein the arrows in the figure represent the flow direction of the cooling gas;

[0035] Figure 3 Schematic diagram of a method for realizing the pre-tightening force of the sealing structure on the upper end surface of the front cover plate in the present invention;

[0036] Figure 4It is a partial enlarged view of the end face sealing structure of the present invention;

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

[0038] Description of reference numerals:

[0039] 1-front cover plate, 11-sealing end face structure, 11a-bow-shaped arm structure, 11b-ear structure, 12-discrete hook of front cover plate, 13-clamping groove, 14-keyway of front cover plate, 15-external comb teeth, 16-internal comb teeth, 17-cold air receiving hole, 1a, 1b-sealing end face on the rear end face of front cover plate, 1c-front end face of radial position in front cover plate, 1d-rear end face of radial position in front cover plate, 1e-assembly joint face of front cover plate, 2-turbine plate, 21-front end face of turbine plate, 22-discrete hook of turbine plate, 23-turbine plate hub, 24-keyway of turbine plate, 27-cold air supply channel, 2a-inner diameter face of turbine plate, 2b-outer diameter face of turbine plate, 3-disc-shaped nozzle stationary part, 37-pre-swirl nozzle, 4-locking block, 5-retaining ring, 6-sealing ring. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. The described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be understood as limiting the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] Example 1

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

[0043] Among them, the disc-shaped nozzle stationary part 3 is connected to the turbine guide by bolts and is axially located on the upstream side of the front cover plate 1. The front cover plate 1 and the turbine disk 2 are integrally assembled and the front cover plate 1 is axially located on the upstream side of the turbine disk 2. The two rotate together when the aircraft engine is in working condition. The space enclosed by the disc-shaped nozzle stationary part 3 and the front cover plate 1 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 1 and the turbine disk 2 forms a cold air sealing chamber, which is used to isolate the cold air, avoid leakage and ensure the effective transmission of the cooling gas. When working, the cooling air supplied by the pre-swirl system to the turbine rotor is drawn out from the two airflows in the combustion chamber, and passes through the pre-swirl nozzle 37 on the nozzle stationary part, the cold air receiving hole 17 on the front cover plate 1, and the cold air supply channel 27 on the turbine disk 2 in turn, and then reaches the turbine rotor to achieve turbine rotor cooling ( Figure 2 ).

[0044] Preferably, a plurality of pre-swirl nozzles 37 are evenly arranged along the circumference at the low radius position of the disc-shaped nozzle stationary part 3, which 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. A plurality of cold air receiving holes 17 are evenly arranged along the circumference at the low radius position of the front cover plate disk 1, and each cold air receiving hole 17 corresponds to the air supply hole 27 on the turbine disk 2 in the axial direction, which is used to guide the cooling gas from the cold air pre-swirl chamber into the cold air sealing chamber. A plurality of cold air supply channels 27 are evenly arranged along the circumference at the high radius position of the turbine disk 2, and each cold air supply channel 27 is radially located on the inner side of the upper end face sealing structure 11, which is used to transport the cooling gas that has been pre-swirled and cooled from the cold air sealing chamber to the cooling path of the turbine rotor. Through the setting of the above cold air path, the cooling airflow drawn from the two airflows in the combustion chamber can achieve sufficient cooling of the turbine rotor under high temperature and high speed conditions after undergoing the processes of pre-swirl, cooling, guiding and sealing along the way.

[0045] In the sealing structure of the pre-swirl air supply system of the gas turbine of the present invention, the front cover plate 1 is provided with outer comb teeth 15 and inner comb teeth 16, wherein the outer comb teeth 15 are arranged at the middle radius position of the front end face of the front cover plate 1 along the circumferential direction, and the inner comb teeth 16 are arranged at the low radius position of the front end face of the front cover plate 1 along the circumferential direction, and the outer comb teeth 15 are arranged on the outer side of each pre-swirl nozzle 37 and the cold air receiving hole 17 in the radial direction, and the inner comb teeth 16 are arranged on the inner side of each pre-swirl nozzle 37 and the cold air receiving hole 17 in the radial direction, so as to prevent the cooling air accelerated by the pre-swirl nozzle from leaking out from the rotating-static gap formed between the nozzle stationary part 3 and the front cover plate 1. And wherein, the design parameters of the outer comb teeth 15 and the inner comb 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, so as to ensure the sealing effect while preventing scraping.

[0046] In the sealing structure of the pre-swirl air supply system of the gas turbine 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 to prevent the turbine rotor cooling air supplied by the pre-swirl system entering from the receiving hole 17 from leaking out from 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 a 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, a front cover plate keyway 14 is evenly distributed along the circumferential direction in the center hole of the front cover plate 1, and a plurality of turbine disk keyways 24 corresponding to each front cover plate keyway 14 are evenly distributed on the outer surface of the center hub of the turbine disk 2. The front cover plate keyway 14 cooperates with the turbine disk keyway 24 on the turbine disk 2 and is connected through a wedge-shaped locking block 4. The wedge-shaped locking block 4 penetrates the front cover plate keyway 14 and the turbine disk keyway 24, and a retaining ring 5 is used to limit the wedge-shaped locking block 4 from coming out, so as to realize torque transmission between the front cover plate 1 and the turbine disk 2 when the aircraft engine is rotating, so that they rotate together.

[0048] In order to take into account both structural reliability and ease of assembly and disassembly, the number of wedge-shaped lock blocks 4 can be designed to be 2 to 4, and they are inserted into the front cover plate keyway 14 and the turbine disk keyway 24 as evenly as possible in the circumferential direction. There is a corresponding relationship between the number of teeth and the tooth width of the front cover plate keyway 14 on the front cover plate 1 and the turbine disk keyway 24 on the turbine disk 2, so that when the front cover plate 1 is pushed in during assembly, the teeth on the front cover plate keyway 14 and the turbine disk keyway 24 correspond one to one, realizing the axial limit of the left end of the front cover plate 1.

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

[0050] The end face sealing structure 11 is designed with an arched arm structure 11a, which is formed by the profile at the high radius position of the front cover plate disk 1 through radial inclination and axial backward inclination. An annular sealing ring 6 is arranged between the end sealing end faces 1a and 1b of the arched arm structure 11a and abuts against the front end face 21 of the turbine disk. The bending structure of the arched arm structure 11a can produce elastic deformation during the assembly process, thereby generating a pre-tightening force to achieve the compression between the sealing end faces 1a and 1b and the end face of the turbine disk 2. Further, the end face sealing structure 11 is designed with a pull ear structure 11b, which, on the one hand, is used to use a tooling hook to elastically deform the arched arm structure 11a and generate a pre-tightening force during assembly; on the other hand, this local structure can be subjected to the centrifugal force when the gas turbine is in the working state, and provide the end face sealing structure 11 with a compression bending moment in the direction of the turbine disk 2, so that the sealing end faces 1a and 1b are further compressed with the front end face 21 of the turbine disk. In addition, a number of front cover plate discrete hooks 12 are evenly distributed along the circumferential direction near the radial position in the rear end surface of the front cover plate disc 1, and a number of turbine disk discrete hooks 22 are evenly distributed along the circumferential direction near the radial position in the front end surface of the turbine disk 2. Each front cover plate discrete hook 12 corresponds to the turbine disk discrete hook 22 in the circumferential position one by one and is snap-fitted in the assembled state to limit the axial displacement of the front cover plate disc 1 and ensure a stable connection between the front cover plate disc 1 and the turbine disk 2 under high-speed rotation.

[0051] Preferably, a torque transmission structure connected by high-strength bolts can be adopted between the front cover plate 1 and the turbine disk 2. A plurality of groups of bolt connection pairs are evenly distributed along the circumferential direction on the mating end faces of the two. Each group of connection pairs includes a through hole penetrating the front cover plate 1 and an internal threaded hole arranged on the turbine disk 2. The front cover plate 1 and the turbine disk 2 are firmly connected by the bolt preload to ensure that relative sliding or loosening will not occur 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 tightened by the cooperation of the nut and the center pull rod. One end of the center pull rod is connected to the center hub of the turbine disk 2 through a spline structure and positioned by a locating pin, and the other end extends out of the end face of the front cover plate 1 and is provided with an external thread, so that the front cover plate 1 is firmly fixed to the turbine disk 2 through the pre-tightening force generated by tightening the nut during installation, thereby effectively preventing axial displacement.

[0053] Preferably, in the end sealing end faces 1a and 1b of the bow-shaped bent arm structure, the end face portion 1a located on the outside of the annular sealing ring and the end face portion 1b located on the inside of the sealing ring are designed to be non-coplanar. By designing the axial dimensions and tolerances of the structure, the end face portion 1a located on the outside of the sealing ring 6 is 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 disc 1 is made of the same high-temperature alloy material as the turbine disc 2, and the disc surface thickness is smaller than the thickness of the turbine disc, so that the deformation of the front cover plate disc 1 is greater than the deformation of the turbine disc 2 under working conditions, which helps to form a tighter assembly relationship between the two and further enhance the sealing effect.

[0055] Preferably, the compression preload force generated by the elastic deformation of the bow-shaped arm structure 11a during the assembly process should be selected to be sufficient to pull the bow-shaped arm structure 11a to deform it, without exceeding the elastic deformation range of the selected front cover plate 1 material, so as to generate sufficient axial clearance between the front cover plate discrete hook 12 and the turbine disc discrete hook 22 to facilitate the subsequent rotation of the front cover plate 1.

[0056] Example 2

[0057] Based on the sealing structure of the pre-swirl air supply system of the gas turbine provided in the above-mentioned embodiment 1, this embodiment 2 further provides an assembly method of the sealing structure. Figure 5 This is an assembly flow chart of the sealing structure of the pre-swirl air supply system of the gas turbine 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, insert the front cover plate keyway 14 into the turbine disk keyway 24, and push the front cover plate 1 into the center hub of the turbine disk 2 along the axial direction to ensure that the two are axially aligned and coaxially positioned. When the cover plate keyway 14 completely passes through the turbine disk keyway 24, the front cover plate discrete hook 12 and the turbine disk discrete hook 22 at the rear end face 1d at the radial position of the front cover plate are still axially overlapped.

[0060] SS2. Apply preload to create axial clearance

[0061] Furthermore, a preload is applied to the front end face 1c at the radial position of the front cover plate to press downward in the direction of the turbine disk. At this time, an axial gap is formed between the front cover plate discrete hook 12 and the turbine disk discrete hook 22 due to elastic deformation. The size of this gap should be controlled within the specified design range. At the same time, the pull ear structure 11b is pulled outward to temporarily disengage the sealing end face 1a and the sealing end face 1b from the front end 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, there is also an axial gap between the sealing end face 1a, the sealing end face 1b and the turbine disk 2. At this time, the front cover plate 1 can be rotated by clamping the clamping groove 13 set 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 opposite relationship, and at the same time, the teeth on the front cover plate keyway 14 and the turbine disk keyway 24 also correspond one by one, so that the front cover plate 1 and the turbine disk 2 are in an angularly aligned state, and then the locking block 4 is inserted into the aligned front cover plate keyway 14 and the turbine disk keyway 24, and the locking block 4 is fixed with the retaining ring 5, so as 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 rebound

[0065] The preload force applied to the front cover plate 1 is withdrawn, and the pull ear structure 11b is gradually loosened to release the pulling force applied thereon, and the bow-shaped curved arm structure 11a rebounds, so that the end sealing end face 1a and the sealing end face 1b of the bow-shaped curved arm structure 11a are in a compression relationship with the front end face 21 of the turbine disk 2, and the front cover plate keyway 14 and the corresponding teeth of the turbine disk keyway 24 are in a compression relationship at the mating surface 1e. Thus, under the condition that the curved arm 11a has initial elastic deformation, the front cover plate 1 is pressed on the turbine disk 2 with an initial preload force. This initial preload force ensures the stability of the sealing structure and avoids 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 compression relationship between the front cover plate keyway 14 and the turbine disk keyway 24 at the assembly joint surface 1e, confirm that the bow-shaped arm structure 11a is in a suitable pre-tightened deformation state, check the sealing effect of the sealing end face, ensure the smooth flow of the cold air flow path, and make appropriate fine adjustments when necessary to ensure the stability and reliability of all components under actual operating conditions.

[0068] The above assembly method can effectively ensure that the gas turbine pre-swirl air supply system sealing structure of the present invention obtains an ideal assembly effect and ensures its stability and reliability under high temperature and high pressure environment. The assembly method is easy to operate and has high reliability, and is particularly suitable for promotion and application in engineering practice.

[0069] Through the above embodiments, the purpose of the present invention is fully and effectively achieved. Although the present invention has been described with respect to the most practical and preferred embodiments currently considered, it should be understood that the present invention is not limited to the disclosed embodiments, and any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A sealing structure for a pre-swirl air supply system of a gas turbine, comprising at least a front cover plate, a turbine plate and a disc-shaped nozzle stationary member, characterized in that: The center of the front cover plate is coaxially fixedly mounted on the turbine plate and is axially located on the upstream side thereof; the disc-shaped nozzle stationary member is fixedly mounted on the turbine guide and is axially located on the upstream side of the front cover plate; the space enclosed by the disc-shaped nozzle stationary member and the front cover plate forms a cold air pre-swirl chamber; the space enclosed by the front cover plate and the turbine plate forms a cold air sealing chamber; The profile at the high radius position of the front cover plate is integrally processed to form a radially inwardly inclined and axially backwardly inclined arcuate arm structure, the end sealing end face of the arcuate arm structure is provided with an annular sealing ring and forms an end face sealing structure abutting against the front end face of the turbine disk, and the outer side of the arcuate arm structure is evenly provided with a plurality of pull ear structures along the circumferential direction, each of the pull ear structures is used to elastically deform the arcuate arm structure with the aid of external force during assembly, so as to generate a pre-tightening force that causes the end sealing end face of the arcuate arm structure to press and abut against the front end face of the turbine disk, and the centrifugal force generated by each of the pull ear structures further enhances the pressing effect between the sealing end faces when the gas turbine is in a working state; And wherein, a plurality of front cover plate discrete hooks are evenly distributed along the circumferential direction near the radial position in the rear end surface of the front cover plate, and a plurality of turbine disk discrete hooks are evenly distributed along the circumferential direction near the radial position in the front end surface of the turbine disk. Each of the front cover plate discrete hooks corresponds to the turbine disk discrete hooks one by one in the circumferential position and is snap-fitted 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 under high-speed rotation.

2. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: A plurality of pre-swirl nozzles are evenly distributed along the circumferential direction at the low radius position of the disc-shaped nozzle stationary part, which are used to accelerate and deflect the cooling airflow led out from the two airflows in the combustion chamber into the cold air pre-swirl cavity and reduce its relative total temperature; a plurality of cold air receiving holes are evenly distributed along the circumferential direction at the low radius position of the front cover plate, and each of the cold air receiving holes corresponds to the air supply hole on the turbine disk in the axial direction, and is used to guide the cooling gas from the cold air pre-swirl cavity into the cold air sealing cavity; a plurality of cold air supply channels are evenly distributed along the circumferential direction at the high radius position of the turbine disk, and each of the cold air supply channels is radially located on the inner side of the upper end face sealing structure, and is used to transport the cooling gas that has been pre-swirled and cooled from the cold air sealing cavity to the cooling path of the turbine rotor.

3. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: The front end surface of the front cover plate is provided with outer comb teeth along the circumferential direction at the middle radius position and inner comb teeth along the circumferential direction at the low radius position, and the outer comb teeth are radially arranged on the outside of each of the pre-swirl nozzles and the cold air receiving holes, and the inner comb teeth are radially arranged on the inside of each of the pre-swirl nozzles and the cold air receiving holes, so as to prevent the cooling gas from leaking from the rotating-static gap between the disc-shaped nozzle stationary part and the front cover plate.

4. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: A plurality of front cover plate keyways are evenly distributed in the circumferential direction in the center hole of the front cover plate, and a plurality of turbine disk keyways corresponding to the front cover plate keyways are evenly distributed on the outer surface of the center hub of the turbine disk. The front cover plate keyways and the turbine disk keyways are connected to each other through wedge-shaped locking blocks, and a retaining ring is provided at the connection to limit the escape of the wedge-shaped locking blocks, thereby realizing a stable torque transmission connection between the front cover plate and the turbine disk.

5. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 4, characterized in that: The number of teeth and the tooth width of the front cover plate keyway and the turbine disk keyway correspond to the number and distribution of the front cover plate discrete hooks and the turbine disk discrete hooks, so that when each of the front cover plate keyways corresponds to the turbine disk keyways one by one in the angular direction, each of the front cover plate discrete hooks and the turbine disk discrete hooks are also in an angularly opposite relationship.

6. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: A torque transmission structure connected by high-strength bolts is adopted between the front cover plate and the turbine disk. A plurality of groups of bolt connection pairs are evenly distributed along the circumferential direction on the mating end surfaces of the two. Each group of connection pairs includes a through hole penetrating the front cover plate and an internal threaded hole arranged on the turbine disk. The front cover plate and the turbine disk are firmly connected by the bolt pre-tightening force.

7. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: The axial limit between the front cover plate and the turbine plate at the left end is tightened by the cooperation of a nut and a center pull rod. One end of the center pull rod is connected to the center hub of the turbine plate through a spline structure and is positioned by a locating pin, and the other end extends out of the end face of the front cover plate and is provided with an external thread, so that the front cover plate is firmly fixed on the turbine plate through the pre-tightening force generated by tightening the nut during installation.

8. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: In the end sealing end face of the bow-shaped curved arm structure, the end face portion located on the outside of the annular sealing ring and the end face portion located on the inside of the annular sealing ring are designed to be non-coplanar. Through the design of the structural axial dimensions and tolerances, the end face portion located on the outside of the annular sealing ring is 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.

9. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: The front cover plate is made of the same high-temperature alloy material as the turbine disk, and its disk surface thickness is smaller than the thickness of the turbine disk, so that the deformation of the front cover plate is greater than the deformation of the turbine disk in the working state, so as to form a closer assembly relationship between the two and further enhance the sealing effect.

10. The sealing structure of the pre-swirl air supply system of a gas turbine according to claim 1, characterized in that: The compression preload force generated by the elastic deformation of the bow-shaped arm structure during the assembly process should be selected to ensure that it is sufficient to pull the bow-shaped arm structure to deform, without exceeding the elastic deformation range of the selected front cover plate material, so as to generate sufficient axial clearance between the discrete hooks of the front cover plate and the discrete hooks of the turbine disk to facilitate the subsequent rotation of the front cover plate.

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