Sealing structure for split frame of hydrogen-cooled turbine generator

Abstract

The present invention relates to the field of design and manufacturing of turbine generators. Disclosed is a sealing structure for a split frame of a hydrogen-cooled turbine generator. The sealing structure comprises first sealing mechanisms, second sealing mechanisms, and sealant injection sealing mechanisms. Each first sealing mechanism is disposed axially on a corresponding horizontal joint surface of a lower half frame of a middle frame section, and the first sealing mechanism performs matching sealing between an upper half frame and the lower half frame that are fixedly connected in the middle frame section. Each second sealing mechanism is disposed circumferentially on a corresponding end shield plane, and the second sealing mechanism performs matching sealing between the end shield and the middle frame section that are fixedly connected. Each sealant injection sealing mechanism injects a sealant into an intersection between the first sealing mechanism and the second sealing mechanism. At an intersection between a horizontal surface of a frame joint plate and a vertical surface of the end shield, a low-pressure region and a high-pressure region of the generator are completely isolated from each other by means of ingenious cooperation of the sealant and sealing strips, thereby achieving hydrogen sealing.

Description

A split-frame sealing structure for a hydrogen-cooled steam turbine generator Technical Field

[0001] This invention belongs to the field of steam turbine generator design and manufacturing, and specifically relates to a split-frame sealing structure for a hydrogen-cooled steam turbine generator. Background Technology

[0002] The generator frame is a crucial component of the generator, possessing sufficient strength and rigidity. Its function is to fix and support the generator stator core and stator coils. For generators using hydrogen as the cooling medium, the frame must also withstand the pressure of the gas and provide sealing and explosion-proof capabilities.

[0003] Large steam turbine generator frames are bulky and complex in shape. They are commonly found in three types: air-cooled split-half frames, hydrogen-cooled integral frames, and hydrogen-cooled three-section frames. Due to transportation requirements, large air-cooled steam turbine generator frames employ an axially split-half structure with horizontal joint plates for easy transport, assembly, and maintenance. Air-cooled steam turbine generators do not have sealing requirements.

[0004] The hydrogen-cooled steam turbine generator features a unique integral frame structure. Its advantages include a compact design, improved rigidity and stability, reduced number of sealing surfaces (avoiding sealing difficulties and hydrogen leakage risks associated with split-structure designs), and simplified manufacturing processes. Disadvantages include inconvenient transportation, limited internal maintenance space, and increased difficulty and time costs for maintenance.

[0005] The three-section generator base is axially divided into three sections, consisting of a middle section and steam and excitation end covers. The three parts are transported separately to the construction site, where they are welded together using airtight welding. For example, the Chinese invention patent specification, CN106208482A, entitled "An Easily Machinable Ultra-Supercritical 1100MW Nuclear Power Generator Base," discloses that this design divides the large generator base into three sections and then welds them together, facilitating machining; the base shell has high strength and good sealing performance.

[0006] However, the above three-section base has the following drawbacks:

[0007] 1. Because the middle section of the base is not divided into two halves, as the capacity of the hydrogen chiller increases, the base shape continues to grow, leading to difficulties in transporting the unit or situations where it cannot be transported at all.

[0008] 2. The middle section of the frame is not split in half, and the installation of the inner stator requires insertion, which is complicated and difficult to operate. Summary of the Invention

[0009] The purpose of this invention is to overcome the aforementioned problems of existing three-section frame structures and to propose a half-frame sealing structure for hydrogen-cooled steam turbine generators. This structure solves the transportation problems caused by the increasing volume of the three-section frame structure, while also addressing the sealing problem during the installation of the middle section of the half-frame frame.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A split-frame sealing structure for a hydrogen-cooled steam turbine generator is characterized by comprising a first sealing mechanism, a second sealing mechanism, and an adhesive injection sealing mechanism. The middle section of the frame is divided into an upper frame and a lower frame, which are fixedly connected. An end cover is fixedly connected to the middle frame. The first sealing mechanism is located axially on the horizontal joint surface of the lower frame, and the upper and lower frames are sealed together by the first sealing mechanism. The second sealing mechanism is located circumferentially on the plane of the end cover, and the end cover and the middle frame are sealed together by the second sealing mechanism. The adhesive injection sealing mechanism injects adhesive at the junction of the first and second sealing mechanisms.

[0012] The end cover includes a steam end cover and an exciter end cover. Both the steam end cover and the exciter end cover are provided with a second sealing mechanism. The steam end cover and the exciter end cover are respectively sealed to the intermediate machine base through the second sealing mechanism.

[0013] The lower half of the machine base has two horizontal joint surfaces, each equipped with a first sealing mechanism along the axial direction.

[0014] There are two joints where the first sealing mechanism on the lower half of the machine base cooperates with the second sealing mechanism on the steam end cover and the exciter end cover to seal, and each joint is equipped with a set of glue injection sealing mechanism.

[0015] The first sealing mechanism includes a first sealing groove and a first sealing strip. The first sealing groove is located axially on the horizontal joint surface of the lower half of the machine base, and the first sealing strip is embedded in the first sealing groove. The upper half of the machine base and the lower half of the machine base are connected by bolts and the first sealing strip is compressed to form a sealing fit.

[0016] The second sealing mechanism includes a second sealing groove and a second sealing strip. The second sealing groove is located on the circumferential surface of the end cover plane, and the second sealing strip is embedded in the second sealing groove. The steam end cover and the middle section base are connected by bolts and the circular second sealing strip is compressed to form a sealing fit.

[0017] The glue injection sealing mechanism includes: a glue injection hole, a glue injection channel, and a glue injection groove. A glue injection hole is provided on the horizontal joint plate of the lower half of the machine base. The glue injection hole is connected to the glue injection channel. The end of the glue injection channel is connected to the glue injection groove. The glue injection groove is adjacent to the junction of the first sealing groove and the second sealing groove. The glue injection groove has a glue injection port. The sealant is injected from the glue injection hole, passes through the glue injection channel to the glue injection groove, and is then squeezed out from the glue injection port to the junction of the first sealing mechanism and the second sealing mechanism to form a seal.

[0018] The glue injection groove is square; two glue injection ports are provided on each of the adjacent surfaces of the glue injection groove, the first sealing groove, and the second sealing groove; the glue injection holes are located on the horizontal joint plate of the lower half of the machine base.

[0019] The injection port is a flared injection port with an inner diameter of 4mm and an outer diameter of 1-1.5mm.

[0020] The distance between the glue injection groove and the first sealing groove and the second sealing groove is 9mm.

[0021] The advantages of using this invention are:

[0022] The three-section generator base adopts an upper and lower half structure, which allows the ever-increasing capacity of the hydrogen-cooled unit to be disassembled into smaller parts, facilitating transportation and internal stator installation, and greatly reducing transportation and installation difficulties. At the same time, at the junction of the horizontal plane of the upper and lower half of the generator base joint plate and the vertical plane of the end cover, sealant and sealing strips are used. Through the cooperation of sealant and sealing strips, the low-pressure air area and the high-pressure hydrogen area in the generator middle section are completely separated, solving the problem of hydrogen leakage and achieving hydrogen sealing.

[0023] Second, the compression of the first and second sealing strips increases the sealing performance between the upper and lower machine bases and in the circumferential direction of the end cover plane.

[0024] 3. Four glue injection sealing mechanisms ensure that all interface surfaces between the end caps and the base are completely sealed, guaranteeing a good sealing effect.

[0025] 4. The two injection ports are flared in shape with an inner diameter of 4mm and an outer diameter of 1-1.5mm. They are designed to be flush with the sealant strip to increase the flow resistance of the sealant and prevent the hydrogen pressure in the high-pressure hydrogen zone from pushing the sealant and causing hydrogen leakage.

[0026] 5. The distance between the injection groove and the first and second sealing grooves is 9, which ensures the fluidity of the sealant while achieving the highest flow resistance.

[0027] 6. All sealing strips are made of hydrogen-resistant material, which improves the service life of the sealing strips. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the split-frame of the hydrogen-cooled steam turbine generator of the present invention;

[0029] Figure 2 is a top view of the sealed half-frame of the hydrogen-cooled steam turbine generator of the present invention;

[0030] Figure 3 is a schematic diagram of the glue injection groove for the split-type machine base of the hydrogen-cooled steam turbine generator of the present invention;

[0031] [Correction 02.04.2026 based on Rule 91] Figure 4 is a schematic diagram of the hydrogen-cooled steam turbine generator of the present invention.

[0032] The markings in the diagram are as follows: 1. Middle section base, 2. Upper half base, 3. Lower half base, 4. End cover, 5. Steam end cover, 6. Excitation end cover, 7. First sealing mechanism, 8. First sealing groove, 9. First sealing strip, 10. Second sealing mechanism, 11. Second sealing groove, 12. Second sealing strip, 13. Adhesive injection sealing mechanism, 14. Adhesive injection hole, 15. Adhesive injection groove channel, 16. Adhesive injection groove, 17. Adhesive injection port, 18. Horizontal joint plate, 19. Low-pressure air zone, 20. High-pressure hydrogen zone. Embodiments of the present invention

[0033] Example 1

[0034] A split-frame sealing structure for a hydrogen-cooled steam turbine generator includes a first sealing mechanism 7, a second sealing mechanism 10, and a glue injection sealing mechanism. The middle section of the frame 1 is divided into an upper frame 2 and a lower frame 3, which are fixedly connected. An end cover 4 is fixedly connected to the middle section of the frame 1. The first sealing mechanism 7 is located axially on the horizontal joint surface of the lower frame 3, and the upper frame 2 and the lower frame 3 are sealed together by the first sealing mechanism 7. The second sealing mechanism 10 is located circumferentially on the plane of the end cover 4, and the end cover 4 and the middle section of the frame 1 are sealed together by the second sealing mechanism 10. The glue injection sealing mechanism injects glue at the junction of the first sealing mechanism 7 and the second sealing mechanism 10.

[0035] The end cover 4 includes a steam end cover 5 and an exciter end cover 6. Both the steam end cover 5 and the exciter end cover 6 are provided with a second sealing mechanism 10. The steam end cover 5 and the exciter end cover 6 are respectively sealed to the intermediate machine base 1 through the second sealing mechanism 10.

[0036] The lower half of the machine base 3 has two horizontal joint surfaces, each of which is provided with a first sealing mechanism 7 along the axial direction.

[0037] The first sealing mechanism 7 on the lower half of the machine base 3 and the second sealing mechanism 10 on the steam end cover 5 and the excitation end cover 6 have two joints, and each joint is equipped with a set of glue injection sealing mechanism.

[0038] The first sealing mechanism 7 includes a first sealing groove 8 and a first sealing strip 9. The first sealing groove 8 is located on the axial direction of the horizontal joint surface of the lower half of the machine base 3, and the first sealing strip 9 is embedded in the first sealing groove 8. The upper half of the machine base 2 and the lower half of the machine base 3 are connected by bolts and the first sealing strip 9 is compressed to form a sealing fit.

[0039] The second sealing mechanism 10 includes a second sealing groove 11 and a second sealing strip 12. The second sealing groove 11 is disposed on the circumferential plane of the end cover 4, and the second sealing strip 12 is embedded in the second sealing groove 11. The steam end cover 5 and the middle section base 1 are connected by bolts and the circular second sealing strip 12 is compressed to form a sealing fit.

[0040] The glue injection sealing mechanism includes: a glue injection hole 14, a glue injection channel 15, and a glue injection groove 16. A glue injection hole 14 is provided on the horizontal joint plate 18 of the lower half of the machine base 3. The glue injection hole 14 is connected to the glue injection channel 15. The end of the glue injection channel 15 is connected to the glue injection groove 16. The glue injection groove 16 is adjacent to the junction of the first sealing groove 8 and the second sealing groove 11. The glue injection groove 16 has a glue injection port 17. The sealant is injected from the glue injection hole 14, passes through the glue injection channel to the glue injection groove 16, and is then squeezed out from the glue injection port 17 to the junction of the first sealing mechanism 7 and the second sealing mechanism 10 to form a seal.

[0041] The glue injection groove 16 is square; two glue injection ports 17 are provided on the adjacent surfaces of the glue injection groove 16, the first sealing groove 8, and the second sealing groove 11; the glue injection hole 14 is provided on the horizontal joint plate 18 of the lower half of the machine base 3.

[0042] The glue injection port 17 is a flared injection port with an inner diameter of 4mm and an outer diameter of 1-1.5mm.

[0043] The distance between the glue injection groove 16 and the first sealing groove 8 and the second sealing groove 11 is 9mm.

[0044] As shown in Figure 1-3, the middle section of the three-section frame adopts an upper and lower half structure, allowing the continuously increasing capacity hydrogen-cooled unit to be disassembled into smaller components, facilitating transportation and internal stator installation, and greatly reducing transportation and installation difficulties. At the intersection of the horizontal plane of the frame joint plate and the vertical plane of the end cover 4, sealant and sealing strips are used to completely separate the generator's low-pressure air zone 19 from the high-pressure hydrogen zone 20, thus achieving hydrogen sealing. The compression of the first sealing strip 9 and the second sealing strip 12 increases the sealing performance between the upper and lower frames and in the circumferential direction of the end cover 4. Two flared injection ports 17 with an inner diameter of 4mm and an outer diameter of 1-1.5mm are connected to the sealing strips to increase the flow resistance of the sealant, preventing the hydrogen pressure in the high-pressure hydrogen zone 20 from pushing the sealant and causing hydrogen leakage. The distance between the glue injection groove 16 and the first sealing groove 8 and the second sealing groove 11 is 9mm, which ensures the fluidity of the sealant while achieving the highest flow resistance. The sealing strips are all made of hydrogen-resistant material to improve their service life. The end cover 4, including the steam end cover 5 and the excitation end cover 6, is symmetrically equipped with glue injection sealing mechanisms 13 to seal the same positions.

[0045] Example 2

[0046] Hydrogen sealing of the upper and lower horizontal joint surfaces of the base: A sealing groove is machined along the axial direction on the horizontal joint surface of the lower half of the base 3, and a sealing strip is embedded in the sealing groove. The upper half of the base 2 and the lower half of the base 3 are connected by bolts and the sealing strip is compressed to achieve hydrogen sealing of the axial horizontal joint surface of the base.

[0047] Hydrogen gas sealing between the base and the steam and exciter end covers 6 on the vertical circumferential surface: sealing grooves are machined on the vertical plane of the steam end cover 5 and the exciter end cover 6, and sealing strips are embedded in the sealing grooves. The steam end cover 5 and the exciter end cover 6 are connected to the base by bolts and the sealing strips are compressed to achieve hydrogen gas sealing between the base and the steam end cover 5 and the exciter end cover 6 on the vertical circumferential surface.

[0048] Hydrogen sealing at the junction of the horizontal plane of the base joint plate and the vertical plane of the end cover 4: A glue injection hole 14 and a glue injection groove 16 are machined on the horizontal joint plate 18 of the upper half of the base 2. The square glue injection groove 16 is adjacent to the sealing strip of the end cover 4 and the horizontal joint sealing strip of the base. A flared glue injection port 17 with an inner diameter of 4mm and an outer diameter of 1-1.5mm is machined on the square glue groove to communicate with the sealing strip of the end cover 4 and the horizontal joint sealing strip of the base.

Claims

1. A split-frame sealing structure for a hydrogen-cooled steam turbine generator, characterized in that: It includes a first sealing mechanism (7), a second sealing mechanism (10), and a glue injection sealing mechanism; the middle section of the machine base (1) is divided into an upper half machine base (2) and a lower half machine base (3), the upper half machine base (2) and the lower half machine base (3) are fixedly connected, the end cover (4) and the middle section machine base (1) are fixedly connected, the first sealing mechanism (7) is set on the axial direction of the horizontal joint surface of the lower half machine base (3), the upper half machine base (2) and the lower half machine base (3) are sealed and fitted by the first sealing mechanism (7), the second sealing mechanism (10) is set on the circumferential direction of the plane of the end cover (4), the end cover (4) and the middle section machine base (1) are sealed and fitted by the second sealing mechanism (10), and the glue injection sealing mechanism injects glue at the junction of the first sealing mechanism (7) and the second sealing mechanism (10).

2. The hydrogen-cooled steam turbine generator split-frame sealing structure according to claim 1, characterized in that: The end cover (4) includes a steam end cover (5) and an exciter end cover (6). Both the steam end cover (5) and the exciter end cover (6) are provided with a second sealing mechanism (10). The steam end cover (5) and the exciter end cover (6) are respectively sealed to the middle section base (1) through the second sealing mechanism (10).

3. A split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 1 or 2, characterized in that: The lower half of the machine base (3) has two horizontal joint surfaces, each of which is provided with a first sealing mechanism (7) along the axial direction.

4. The split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 3, characterized in that: The first sealing mechanism (7) on the lower half of the machine base (3) and the second sealing mechanism (10) on the steam end cover (5) and the excitation end cover (6) have two joints, and each joint is equipped with a set of glue injection sealing mechanism.

5. A split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 1, 2, or 4, characterized in that: The first sealing mechanism (7) includes a first sealing groove (8) and a first sealing strip (9). The first sealing groove (8) is located on the axial side of the horizontal joint surface of the lower half of the machine base (3), and the first sealing strip (9) is embedded in the first sealing groove (8). The upper half of the machine base (2) and the lower half of the machine base (3) are connected by bolts and the first sealing strip (9) is compressed to form a sealing fit.

6. The split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 5, characterized in that: The second sealing mechanism (10) includes a second sealing groove (11) and a second sealing strip (12). The second sealing groove (11) is located on the circumferential plane of the end cover (4), and the second sealing strip (12) is embedded in the second sealing groove (11). The steam end cover (5) and the middle section base (1) are connected by bolts and the circular second sealing strip (12) is compressed to form a sealing fit.

7. The hydrogen-cooled steam turbine generator split-frame sealing structure according to claim 6, characterized in that: The glue injection sealing mechanism includes: a glue injection hole (14), a glue injection channel (15), and a glue injection groove (16). A glue injection hole (14) is provided on the horizontal joint plate (18) of the lower half of the machine base (3). The glue injection hole (14) is connected to the glue injection channel (15). The glue injection channel (15) is connected to the glue injection groove (16) at its end. The glue injection groove (16) is adjacent to the junction of the first sealing groove (8) and the second sealing groove (11). The glue injection groove (16) has a glue injection port (17). The sealant is injected from the glue injection hole (14), passes through the glue injection channel to the glue injection groove (16), and is squeezed out from the glue injection port (17) to the junction of the first sealing mechanism (7) and the second sealing mechanism (10) to form a seal.

8. The split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 6, characterized in that: The glue injection groove (16) is square; two glue injection ports (17) are provided on the adjacent surfaces of the glue injection groove (16), the first sealing groove (8), and the second sealing groove (11); the glue injection hole (14) is provided on the horizontal joint plate (18) of the lower half of the machine base.

9. A split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 1 or 6, characterized in that: The injection port (17) is a flared injection port (17) with an inner diameter of 4 mm and an outer diameter of 1-1.5 mm.

10. A split-frame sealing structure for a hydrogen-cooled steam turbine generator according to claim 1 or 2, characterized in that: The distance between the glue injection groove (16) and the first sealing groove (8) and the second sealing groove (11) is 9mm.

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