Half engine base sealing structure of hydrogen-cooled steam turbine generator

Abstract

The invention discloses a split base sealing structure of a hydrogen-cooled steam turbine generator, and belongs to the field of design and manufacturing of steam turbine generators. Comprising a first sealing mechanism, a second sealing mechanism and a glue injection sealing mechanism, the first sealing mechanism is arranged in the axial direction of the horizontal joint face of the lower half machine base of the middle-section machine base, and the first sealing mechanism conducts matched sealing on the upper half machine base and the lower half machine base which are fixedly connected in the middle-section machine base. The second sealing mechanism is arranged in the circumferential direction of the plane of the end cover and is used for sealing the fixedly connected end cover and the middle-section engine base in a matched manner; the glue injection sealing mechanism injects glue to the joint of the first sealing mechanism and the second sealing mechanism. A low-pressure area and a high-pressure area of the generator are thoroughly separated at the joint of the horizontal plane of the joint plate of the base and the vertical plane of the end cover through ingenious matching of the sealant and the adhesive tape, so that hydrogen sealing is realized.

Description

Technical Field

[0001] The present invention belongs to the field of design and manufacture of turbo-generators, and particularly relates to a split frame sealing structure for a hydrogen-cooled turbo-generator. Background Art

[0002] The frame is an important component of the generator, having sufficient strength and stiffness, and its function is to fix and support the stator core and stator coils of the generator. For a generator using hydrogen as the cooling medium, the frame also needs to withstand the sealing and explosion-proof functions under gas pressure.

[0003] The frames of large turbo-generators are huge and complex in shape. There are three common types: air-cooled split frames, hydrogen-cooled integral frames, and hydrogen-cooled three-section frames. Due to transportation requirements, the frame of a large air-cooled turbo-generator adopts an axial up-and-down split structure, connected by a horizontal joint plate, which is convenient for transportation, assembly, and maintenance. The air-cooled turbo-generator has no sealing requirements.

[0004] The integral frame of a hydrogen-cooled turbo-generator has a unique structure. Its advantages are that it is structurally compact, can provide better rigidity and stability, helps to reduce the number of sealing surfaces, avoids the sealing problems and hydrogen leakage risks that may be brought by the split structure, and simplifies the manufacturing process, etc. Its disadvantages are: inconvenient transportation, limited internal maintenance space, increasing the difficulty and time cost of maintenance.

[0005] The three-section frame divides the frame axially into three sections, consisting of a middle-section frame and steam and exciter end covers. The three parts are transported to the construction site separately and welded into a whole at the construction site using airtight welds. For example, the Chinese invention patent specification with the patent name: An easily machined ultra-supercritical 1100MW nuclear power generator frame, application publication number: CN106208482A discloses that this design divides the large frame into three sections and then welds them into a whole, which is convenient for machining; the frame shell has high strength and good sealing performance.

[0006] However, the above three-section frame has the following defects: 1. Since the middle-section frame is not split, as the capacity of the hydrogen-cooled unit increases, the outer shape of the frame continuously increases, resulting in difficult transportation or even inability to transport the unit.

[0007] 2. The middle-section frame adopts a non-split form, and the installation of the inner stator requires insertion, which is complex in operation and difficult in installation. Summary of the Invention

[0008] The purpose of the present invention is to overcome the above problems existing in the existing three-section frame, and propose a split frame sealing structure for a hydrogen-cooled turbo-generator, which solves the transportation problem caused by the continuously increasing volume of the three-section frame and at the same time solves the sealing problem in the installation of the middle-section frame of the split frame.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows: A split frame sealing structure for a hydrogen-cooled turbogenerator, characterized in that it comprises a first sealing mechanism, a second sealing mechanism and a glue injection sealing mechanism; the middle frame of the frame is divided into an upper half frame and a lower half frame, the upper half frame and the lower half frame are fixedly connected, the end cover and the middle frame are fixedly connected, the first sealing mechanism is arranged axially on the horizontal joint surface of the lower half frame, the upper half frame and the lower half frame are hermetically matched through the first sealing mechanism, the second sealing mechanism is arranged circumferentially on the end cover plane, and the end cover and the middle frame are hermetically matched through the second sealing mechanism, and the glue injection sealing mechanism injects glue at the junction of the first sealing mechanism and the second sealing mechanism.

[0010] The end cover includes a steam end cover and an exciter end cover, and the second sealing mechanism is arranged on both the steam end cover and the exciter end cover. The steam end cover and the exciter end cover are respectively hermetically matched with the middle frame through the second sealing mechanism.

[0011] There are 2 horizontal joint surfaces of the lower half frame, and the first sealing mechanism is arranged axially on both of them.

[0012] There are 2 junctions where the first sealing mechanism on the lower half frame is respectively matched and sealed with the second sealing mechanism on the steam end cover and the exciter end cover, and 1 set of glue injection sealing mechanism is correspondingly arranged at each junction.

[0013] The first sealing mechanism includes a first sealing groove and a first sealing rubber strip. The first sealing groove is arranged axially on the horizontal joint surface of the lower half frame, and the first sealing rubber strip is embedded in the first sealing groove; the upper half frame and the lower half frame are connected by bolts and compress the first sealing rubber strip to form a sealing fit.

[0014] The second sealing mechanism includes a second sealing groove and a second sealing rubber strip. The second sealing groove is arranged circumferentially on the end cover plane, and the second sealing rubber strip is embedded in the second sealing groove; a circular second sealing rubber strip is compressed by bolts between the steam end cover and the middle frame to form a sealing fit.

[0015] The glue injection sealing mechanism includes: a glue injection hole, a glue injection groove channel and a glue injection groove. A glue injection hole is arranged on the horizontal joint plate of the lower half frame. The glue injection hole is connected to the glue injection groove channel, and the end of the glue injection groove channel is connected with a glue injection groove. The glue injection groove is adjacent to the junction of the first sealing groove and the second sealing groove, and there is a glue injection port on the glue injection groove; the sealing glue is injected from the glue injection hole, passes through the injection channel to the glue injection groove and then is extruded from the glue injection port to the junction of the first sealing mechanism and the second sealing mechanism to form a seal.

[0016] The glue injection groove is square; there are 2 glue injection ports respectively arranged on the adjacent surfaces of the glue injection groove and the first sealing groove and the second sealing groove; the glue injection hole is arranged on the horizontal joint plate of the lower half frame.

[0017] The size of the glue injection port is a flared glue injection port with an inner diameter of 4 mm and an outer diameter of 1 - 1.5 mm.

[0018] The distance between the glue injection groove and the first and second sealing grooves is 9 mm.

[0019] The advantages of adopting the present invention are as follows: First, the middle section of the three-section machine base adopts an upper and lower half structure, so that the hydrogen-cooled generator set with continuously increasing capacity can be disassembled into smaller parts, which is convenient for transportation and also convenient for the installation of the inner stator, greatly reducing the transportation and installation difficulties; at the same time, at the junction of the horizontal plane of the joint plate of the upper and lower half machine bases and the vertical plane of the end cover, a method of using sealant and sealing strips is adopted. Through the cooperation of the sealant and the sealing strips, the low-pressure air area in the middle section of the generator is completely separated from the high-pressure hydrogen area, solving the problem of hydrogen leakage and realizing hydrogen sealing.

[0020] Second, the compression of the first and second sealing strips increases the sealing performance between the upper and lower machine bases and the circumferential direction of the end cover plane.

[0021] Third, 4 glue injection and sealing mechanisms ensure that all the interfaces between the end covers and the machine base are completely sealed, ensuring the sealing effect.

[0022] Fourth, the two glue injection ports are flared glue injection ports with an inner diameter of 4 mm and an outer diameter of 1 - 1.5 mm, which are just connected with the sealing strips, so as to increase the flow resistance of the sealant, so that the hydrogen pressure in the high-pressure hydrogen area will not push the sealant to cause hydrogen leakage.

[0023] Fifth, the distance between the glue injection groove and the first and second sealing grooves is 9, achieving the highest flow resistance state while ensuring the fluidity of the sealant.

[0024] Sixth, all the sealing strips are made of hydrogen-resistant materials, improving the service life of the sealing strips. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the split machine base of the hydrogen-cooled steam turbine generator of the present invention; Figure 2 It is a top view of the seal of the split machine base of the hydrogen-cooled steam turbine generator of the present invention; Figure 3 It is a schematic diagram of the glue injection groove of the split machine base of the hydrogen-cooled steam turbine generator of the present invention; Figure 4 It is a schematic diagram of the hydrogen-cooled steam turbine generator of the present invention.

[0026] The markings in the figure are: 1. Middle section frame, 2. Upper half frame, 3. Lower half frame, 4. End cover, 5. Steam end cover, 6. Excitation end cover, 7. First sealing mechanism, 8. First sealing groove, 9. First sealing rubber strip, 10. Second sealing mechanism, 11. Second sealing groove, 12. Second sealing rubber strip, 13. Glue injection sealing mechanism, 14. Glue injection hole, 15. Glue injection groove channel, 16. Glue injection groove, 17. Glue injection port, 18. Horizontal joint plate, 19. Low air pressure area, 20. High hydrogen pressure area. Detailed implementation mode

[0027] Embodiment 1 A split frame sealing structure for a hydrogen-cooled turbogenerator includes a first sealing mechanism 7, a second sealing mechanism 10 and a glue injection sealing mechanism; the middle section frame 1 of the frame is divided into an upper half frame 2 and a lower half frame 3, the upper half frame 2 and the lower half frame 3 are fixedly connected, the end cover 4 and the middle section frame 1 are fixedly connected, the first sealing mechanism 7 is arranged axially on the horizontal joint surface of the lower half frame 3, the upper half frame 2 and the lower half frame 3 are hermetically matched through the first sealing mechanism 7, the second sealing mechanism 10 is arranged circumferentially on the plane of the end cover 4, and the end cover 4 and the middle section frame 1 are hermetically matched through 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.

[0028] The end cover 4 includes a steam end cover 5 and an excitation end cover 6. The second sealing mechanism 10 is arranged on both the steam end cover 5 and the excitation end cover 6. The steam end cover 5 and the excitation end cover 6 are respectively hermetically matched with the middle section frame 1 through the second sealing mechanism 10.

[0029] There are 2 horizontal joint surfaces of the lower half frame 3, and the first sealing mechanism 7 is arranged axially on both of them.

[0030] There are 2 junctions where the first sealing mechanism 7 on the lower half frame 3 respectively cooperates with the second sealing mechanism 10 on the steam end cover 5 and the excitation end cover 6 for sealing. One set of glue injection sealing mechanism is correspondingly arranged at each junction.

[0031] The first sealing mechanism 7 includes a first sealing groove 8 and a first sealing rubber strip 9. The first sealing groove 8 is arranged axially on the horizontal joint surface of the lower half frame 3, and the first sealing rubber strip 9 is embedded in the first sealing groove 8; the upper half frame 2 and the lower half frame 3 are connected by bolts and compress the first sealing rubber strip 9 to form a sealing fit.

[0032] The second sealing mechanism 10 includes a second sealing groove 11 and a second sealing rubber strip 12. The second sealing groove 11 is arranged circumferentially on the plane of the end cover 4, and the second sealing rubber strip 12 is embedded in the second sealing groove 11; a circular second sealing rubber strip 12 is compressed by bolts between the steam end cover 5 and the middle section frame 1 to form a sealing fit.

[0033] The glue injection and sealing mechanism includes: a glue injection hole 14, a glue injection groove 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 base 3. The glue injection hole 14 is connected to the glue injection groove channel 15, and the end of the glue injection groove channel 15 is connected to a 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, and there is a glue injection port 17 on the glue injection groove 16. The sealing glue is injected from the glue injection hole 14, passes through the glue injection channel to the glue injection groove 16, and then is extruded 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.

[0034] The glue injection groove 16 is square; there are 2 glue injection ports 17 provided on each of the adjacent surfaces of the glue injection groove 16 with 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 base 3.

[0035] The size of the glue injection port 17 is a flared glue injection port 17 with an inner diameter of 4 mm and an outer diameter of 1 - 1.5 mm.

[0036] The distance between the glue injection groove 16 and the first sealing groove 8 and the second sealing groove 11 is 9 mm.

[0037] As Figures 1-3 shown, the middle section of the three - section base adopts an upper and lower half structure, disassembling the hydrogen - cooled generator set with increasing capacity into smaller - sized parts, which is convenient for transportation and also for the installation of the inner stator, greatly reducing the transportation and installation difficulties. At the junction of the horizontal plane of the base joint plate and the vertical plane of the end cover 4, through the cooperation of the sealing glue and the sealing rubber strip, the low - pressure air area 19 of the generator is completely separated from the high - pressure hydrogen area 20, thus achieving hydrogen sealing. The compression of the first sealing rubber strip 9 and the second sealing rubber strip 12 increases the sealing performance between the upper and lower bases and the circumferential direction of the end cover 4 plane. The two glue injection ports 17 are flared glue injection ports 17 with an inner diameter of 4 mm and an outer diameter of 1 - 1.5 mm, which just communicate with the sealing rubber strip, so as to increase the flow resistance of the sealing glue, preventing the hydrogen pressure in the high - pressure hydrogen area 20 from pushing the sealing glue 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 9 mm, achieving the highest flow resistance state while ensuring the fluidity of the sealing glue. The sealing rubber strips are all made of hydrogen - resistant materials to improve the service life of the sealing rubber strips. The end cover 4 includes a steam - end cover 5 and an exciter - end cover 6, and the glue injection and sealing mechanism 13 is symmetrically arranged to seal the same position.

[0038] Embodiment 2 Hydrogen sealing of the upper and lower horizontal joint surfaces of the base: A sealing groove is machined axially on the horizontal joint surface of the lower half base 3, and a sealing strip is embedded in the sealing groove. The upper half base 2 and the lower half 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.

[0039] Hydrogen seal for the vertical circumferential surface between the machine base and the steam and exciter end covers 6: Seal grooves are machined circumferentially on the vertical planes of the steam end cover 5 and the exciter end cover 6. Sealing strips are embedded in the seal grooves. The steam end cover 5 and the exciter end cover 6 are bolted to the machine base and the sealing strips are compressed to achieve hydrogen seal for the vertical circumferential surface between the machine base and the steam end cover 5 and the exciter end cover 6.

[0040] Hydrogen seal at the intersection of the horizontal plane of the machine base joint plate and the vertical plane of the end cover 4: Glue injection holes 14 and glue injection grooves 16 are machined on the horizontal joint plate 18 of the upper half of the machine 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 machine base, and trumpet-shaped glue injection ports 17 with an inner diameter of 4 mm and an outer diameter of 1 - 1.5 mm are machined on each of the square glue grooves to communicate with the sealing strip of the end cover 4 and the horizontal joint of the machine base.

Claims

1. A split frame sealing structure for a hydrogen-cooled turbogenerator, characterized in that: It includes a first sealing mechanism (7), a second sealing mechanism (10) and a glue injection sealing mechanism; the middle section base (1) of the machine base is divided into an upper half base (2) and a lower half base (3), the upper half base (2) and the lower half base (3) are fixedly connected, the end cover (4) and the middle section base (1) are fixedly connected, the first sealing mechanism (7) is arranged axially on the horizontal joint surface of the lower half base (3), the upper half base (2) and the lower half base (3) are sealingly fitted through the first sealing mechanism (7), the second sealing mechanism (10) is arranged circumferentially on the plane of the end cover (4), and the end cover (4) and the middle section base (1) are sealingly fitted through 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 split frame sealing structure of a hydrogen-cooled turbogenerator according to claim 1, characterized in that: The end cover (4) includes a steam end cover (5) and an exciter end cover (6), the second sealing mechanism (10) is arranged on both the steam end cover (5) and the exciter end cover (6), and the steam end cover (5) and the exciter end cover (6) are respectively sealingly fitted with the middle section base (1) through the second sealing mechanism (10).

3. A split frame sealing structure for a hydrogen-cooled turbogenerator according to claim 1 or 2, characterized in that: There are 2 horizontal joint surfaces of the lower half base (3), and the first sealing mechanism (7) is arranged axially along both of them.

4. A split frame sealing structure for a hydrogen-cooled turbogenerator according to claim 3, characterized in that: There are 2 junctions where the first sealing mechanism (7) on the lower half base (3) is respectively fitted and sealed with the second sealing mechanism (10) on the steam end cover (5) and the exciter end cover (6), and 1 set of glue injection sealing mechanism is correspondingly arranged at each junction.

5. A split frame sealing structure for a hydrogen-cooled turbogenerator according to claim 1 or 2 or 4, characterized in that: The first sealing mechanism (7) includes a first sealing groove (8) and a first sealing rubber strip (9), the first sealing groove (8) is arranged axially on the horizontal joint surface of the lower half base (3), and the first sealing rubber strip (9) is embedded in the first sealing groove (8); the upper half base (2) and the lower half base (3) are connected by bolts and compress the first sealing rubber strip (9) to form a sealing fit.

6. The split frame sealing structure of a hydrogen-cooled turbogenerator according to claim 5, wherein: The second sealing mechanism (10) includes a second sealing groove (11) and a second sealing rubber strip (12), the second sealing groove (11) is arranged circumferentially on the plane of the end cover (4), and the second sealing rubber strip (12) is embedded in the second sealing groove (11); a sealing fit is formed between the steam end cover (5) and the middle section base (1) by connecting them with bolts and compressing the circular second sealing rubber strip (12).

7. A split frame sealing structure for a hydrogen-cooled turbogenerator according to claim 6, characterized in that: The glue injection sealing mechanism includes: a glue injection hole (14), a glue injection groove channel (15) and a glue injection groove (16). The glue injection hole (14) is arranged on the horizontal joint plate (18) of the lower half base (3), the glue injection hole (14) is connected to the glue injection groove channel (15), the end of the glue injection groove channel (15) is connected with a 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), and there is a glue injection port (17) on the glue injection groove (16); the sealing glue is injected from the glue injection hole (14), passes through the glue injection channel to the glue injection groove (16), and then is extruded 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. A split frame sealing structure for a hydrogen-cooled turbogenerator according to claim 6, characterized in that: The glue injection groove (16) is square; there are 2 glue injection ports (17) provided on each of the adjacent surfaces of the glue injection groove (16) and 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 turbogenerator according to claim 1 or 6, characterized in that: The size of the glue injection port (17) is a flared glue 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 turbogenerator 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 9 mm.

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