Double-seal steam seal structure

Abstract

The utility model relates to the technical field of steam turbines, in particular to a double-seal steam seal structure which comprises a rotor, a steam seal body and a cylinder body. A first steam seal long tooth, a first steam seal short tooth and a second steam seal short tooth are sequentially and fixedly arranged on the inner wall of the steam seal body in the steam flow advancing direction, a follow-up suspension steam seal tooth is installed on the inner wall of the second steam seal short tooth and located on the front side of the second steam seal short tooth, and a first annular gap is defined between the outer wall of the steam seal body and the inner wall of the cylinder body. A second annular gap is defined between the first steam seal short teeth and the second steam seal short teeth, and a steam inlet hole communicated with the first annular gap and the second annular gap is formed in the steam seal body. The steam seal structure has a double-sealing structure, is exquisite in structure and simple to install, greatly reduces the flow speed and flow of steam entering the steam seal body by enabling the steam to generate hedging on the outlet side of the second annular gap, effectively prevents the steam from flowing out, and obviously enhances the sealing performance of the steam seal structure.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbines, in particular to a double-sealing steam seal structure. Background Art

[0002] A steam seal needs to be installed at the shaft end of the steam turbine to isolate the high-temperature and high-pressure fluid inside the turbine, prevent leakage and heat dissipation, and filter and lubricate the air entering the sealed chamber to reduce friction, wear and extend the service life of the turbine.

[0003] A Chinese utility model patent with publication number CN209324437U discloses a steam turbine shaft end combined steam seal device, which uses a plurality of upper steam seal teeth and lower steam seal teeth to form a labyrinth steam seal. Not only is the installation and maintenance process rather complicated, but the labyrinth steam seal also has a poor effect in consuming steam seal leakage energy. Utility Model Content

[0004] The purpose of the utility model is to provide a double-sealed steam seal structure to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a double-sealing steam seal structure, comprising a rotor, a steam seal body gap-sleeved outside the rotor, and a cylinder body fixedly sleeved on the outer wall of the steam seal body; the outer wall of the rotor is fixedly provided with a plurality of convex rings arranged at equal intervals along its axial direction, an annular groove is enclosed between two adjacent convex rings, the inner wall of the steam seal body is fixedly provided with a first steam seal long tooth, a first steam seal short tooth and a second steam seal short tooth in sequence along the forward direction of the steam flow, a follower suspended steam seal tooth is installed on the inner wall of the second steam seal short tooth and at the front side of the second steam seal short tooth, the first steam seal long tooth and the follower suspended steam seal tooth both extend into the annular groove, a first annular gap is enclosed between the outer wall of the steam seal body and the inner wall of the cylinder body, a second annular gap is enclosed between the first steam seal short tooth and the second steam seal short tooth, the second annular gap is aligned with the convex ring, and a steam inlet hole connecting the first annular gap and the second annular gap is opened on the steam seal body.

[0006] Optionally, the first steam seal short tooth and the second steam seal short tooth have the same shape and size, the first steam seal short tooth is a leather cup-shaped structure, the angle between the side of the first steam seal short tooth close to the first steam seal long tooth and the axis of the rotor is 65°, and the angle between the side of the first steam seal short tooth away from the first steam seal long tooth and the axis of the rotor is 55°.

[0007] Optionally, a second steam seal long tooth, a third steam seal short tooth, a fourth steam seal short tooth, a third steam seal long tooth, a fifth steam seal short tooth, a sixth steam seal short tooth, a fourth steam seal long tooth, a seventh steam seal short tooth and an eighth steam seal short tooth are fixedly provided in sequence on the inner wall of the steam seal body and located on the rear side of the second steam seal short tooth along the forward direction of the steam flow, and the follower suspended steam seal tooth is arranged between the sixth steam seal short tooth and the fourth steam seal long tooth.

[0008] Optionally, a clamping block is fixedly provided on the outer wall of the steam seal body and located at the front side of the first annular gap, and a clamping groove matched with the clamping block is opened on the inner wall of the cylinder body.

[0009] Compared with the prior art, the utility model has the following beneficial effects: the utility model has a double sealing structure with sophisticated structure and simple installation. By making the steam collide at the outlet side of the second annular gap, the flow rate and flow of steam entering the steam seal body are greatly reduced, the outflow of steam is effectively hindered, and the sealing performance of the steam seal structure is significantly enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of the utility model;

[0011] Figure 2 for Figure 1 The enlarged structural diagram of the middle A part;

[0012] Figure 3 It is a half-section view of the steam seal body in the utility model.

[0013] In the figure: 1. rotor; 2. convex ring; 3. annular groove; 4. steam seal body; 5. cylinder body; 6. first annular gap; 7. first steam seal long teeth; 8. first steam seal short teeth; 9. second steam seal short teeth; 10. follower suspended steam seal teeth; 11. second annular gap; 12. steam inlet hole; 13. second steam seal long teeth; 14. third steam seal short teeth; 15. fourth steam seal short teeth; 16. third steam seal long teeth; 17. fifth steam seal short teeth; 18. sixth steam seal short teeth; 19. fourth steam seal long teeth; 20. seventh steam seal short teeth; 21. eighth steam seal short teeth; 22. clamping block; 23. clamping groove. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0015] Example: See Figures 1 to 3The utility model provides a double-sealing steam seal structure, including a rotor 1, a steam seal body 4 which is sleeved on the outside of the rotor 1, and a cylinder body 5 which is fixedly sleeved on the outer wall of the steam seal body 4. The outer wall of the rotor 1 is integrally formed with a plurality of convex rings 2 which are arranged at equal intervals along its axial direction, and an annular groove 3 is enclosed between two adjacent convex rings 2. The inner wall of the steam seal body 4 is integrally formed with a first steam seal long tooth 7, a first steam seal short tooth 8 and a second steam seal short tooth 9 in sequence along the forward direction of the steam flow, and a follower suspended steam seal tooth 10 is installed on the inner wall of the second steam seal short tooth 9 and in front of the second steam seal short tooth 9. The follower suspended steam seal tooth 10 is installed on the steam seal body 4 by means of a snap connection. The first steam seal long tooth 7 and the follower suspended steam seal tooth 10 both extend into the annular groove 3. A first annular gap 6 is enclosed between the outer wall of the steam seal body 4 and the inner wall of the cylinder body 5. A clamping block 22 is fixedly provided on the outer wall of the steam seal body 4 and located in front of the first annular gap 6. A clamping groove 23 matching the clamping block 22 is provided on the inner wall of the cylinder body 5.

[0016] A second annular gap 11 is enclosed between the first steam seal short tooth 8 and the second steam seal short tooth 9, and the second annular gap 11 is aligned with the convex ring 2. A steam inlet hole 12 connecting the first annular gap 6 and the second annular gap 11 is provided on the steam seal body 4. There are a plurality of steam inlet holes 12, and the plurality of steam inlet holes 12 are evenly arranged in annular shape about the axis of the steam seal body 4. The first steam seal short tooth 8 and the second steam seal short tooth 9 have the same shape and size. The first steam seal short tooth 8 is a leather cup-shaped structure. The side of the first steam seal short tooth 8 close to the first steam seal long tooth 7 and the axis of the rotor 1 have an angle of 65°, and the side of the first steam seal short tooth 8 away from the first steam seal long tooth 7 and the axis of the rotor 1 have an angle of 55°.

[0017] Steam is diffusive during the flow process. When the steam enters the steam seal body 4, it is divided into two streams at the rear end face of the first steam seal long tooth 7, namely steam flow A and steam flow B. Steam flow A enters the first annular gap 6 along the rear end face of the steam seal body 4, and enters the second annular gap 11 from the steam inlet 12. Steam flow B moves from between the first steam seal long tooth 7 and the rotor 1 toward the second annular gap 11. Since the first steam seal short tooth 8 and the second steam seal short tooth 9 are both inclined toward the first steam seal long tooth 7, steam flow A on the outlet side of the second annular gap 11 creates an impact with steam flow B, greatly reducing the flow velocity and flow rate of steam entering the steam seal body 4, effectively hindering the outflow of steam, and significantly enhancing the sealing performance of the steam seal structure. The first annular gap 6, the steam inlet hole 12 and the second annular gap 11 constitute the first sealing structure of the steam seal body 4. The follower suspended steam seal tooth 10 has follow-up and yielding properties. The gap value between the follower suspended steam seal tooth 10 and the rotor 1 can be very small, forming the second sealing structure of the steam seal body 4. The utility model has a double sealing structure.

[0018] On the basis of the above embodiment, the second steam seal long teeth 13, the third steam seal short teeth 14, the fourth steam seal short teeth 15, the third steam seal long teeth 16, the fifth steam seal short teeth 17, the sixth steam seal short teeth 18, the fourth steam seal long teeth 19, the seventh steam seal short teeth 20 and the eighth steam seal short teeth 21 are fixedly arranged in sequence on the inner wall of the steam seal body 4 and located at the rear side of the second steam seal short teeth 9 along the advancing direction of the steam flow, and the follower suspension steam seal teeth 10 are arranged between the sixth steam seal short teeth 18 and the fourth steam seal long teeth 19. The second steam seal long teeth 13, the third steam seal short teeth 14, the fourth steam seal short teeth 15, the third steam seal long teeth 16, the fifth steam seal short teeth 17, the sixth steam seal short teeth 18, the fourth steam seal long teeth 19, the seventh steam seal short teeth 20 and the eighth steam seal short teeth 21 increase the complexity of the inner wall of the steam seal body 4, so that the inner wall of the steam seal body 4 has multiple labyrinth seal structures, further enhancing the sealing performance of the steam seal body 4.

[0019] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A double-seal steam seal structure, comprising a rotor (1), a steam seal body (4) sleeved outside the rotor (1) in a clearance manner, and a cylinder body (5) fixedly sleeved on the outer wall of the steam seal body (4); the outer wall of the rotor (1) is fixedly provided with a plurality of convex rings (2) arranged at equal intervals along its axial direction, and an annular groove (3) is enclosed between two adjacent convex rings (2), characterized in that: The inner wall of the steam seal body (4) is fixedly provided with a first steam seal long tooth (7), a first steam seal short tooth (8) and a second steam seal short tooth (9) in sequence along the forward direction of the steam flow; a follower floating steam seal tooth (10) is installed on the inner wall of the second steam seal short tooth (9) and in front of the second steam seal short tooth (9); the first steam seal long tooth (7) and the follower floating steam seal tooth (10) both extend into the annular groove (3); a first annular gap (6) is enclosed between the outer wall of the steam seal body (4) and the inner wall of the cylinder body (5); a second annular gap (11) is enclosed between the first steam seal short tooth (8) and the second steam seal short tooth (9); the second annular gap (11) is aligned with the convex ring (2); and a steam inlet hole (12) is opened on the steam seal body (4) to connect the first annular gap (6) and the second annular gap (11).

2. The double-seal steam seal structure according to claim 1, characterized in that: The first steam seal short tooth (8) and the second steam seal short tooth (9) have the same shape and size. The first steam seal short tooth (8) is a leather cup-shaped structure. The angle between the side of the first steam seal short tooth (8) close to the first steam seal long tooth (7) and the axis of the rotor (1) is 65°, and the angle between the side of the first steam seal short tooth (8) away from the first steam seal long tooth (7) and the axis of the rotor (1) is 55°.

3. The double-seal steam seal structure according to claim 1, characterized in that: A second steam seal long tooth (13), a third steam seal short tooth (14), a fourth steam seal short tooth (15), a third steam seal long tooth (16), a fifth steam seal short tooth (17), a sixth steam seal short tooth (18), a fourth steam seal long tooth (19), a seventh steam seal short tooth (20) and an eighth steam seal short tooth (21) are fixedly arranged in sequence on the inner wall of the steam seal body (4) and located at the rear side of the second steam seal short tooth (9) along the forward direction of the steam flow, and the follower floating steam seal tooth (10) is arranged between the sixth steam seal short tooth (18) and the fourth steam seal long tooth (19).

4. The double-seal steam seal structure according to claim 1, characterized in that: A clamping block (22) is fixedly provided on the outer wall of the steam seal body (4) and located in front of the first annular gap (6), and a clamping groove (23) matching the clamping block (22) is provided on the inner wall of the cylinder body (5).

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