A spring plate for a steam seal and a steam seal

Abstract

The application provides a spring sheet for steam seal and steam seal, and relates to the field of spring sheet for steam seal.The spring sheet for steam seal comprises a support body, the support body is in an arch type, fixed support feet and sliding support feet are arranged at two ends of the support body respectively, a clamping groove is arranged on the fixed support feet, and the clamping groove is used for positioning the fixed support feet.The spring sheet for steam seal can reduce the contact area of the spring sheet and the steam seal body, reduce the friction force, enhance the strength of the spring sheet for steam seal, and is not prone to breaking, thereby prolonging the service life.

Description

Technical Field

[0001] The present invention relates to the field of spring sheets for steam seals, in particular to a spring sheet for steam seals and a steam seal. Background Art

[0002] When the steam turbine is running, an appropriate gap must be left between the rotating part and the stationary part to ensure that there is no friction between the moving and static parts. The steam seal is a device that ensures an appropriate gap between the moving and static parts and prevents steam from leaking from the moving and static parts, or air from leaking from the shaft end into the vacuum part of the cylinder. The steam seal can be divided into end steam seals, partition steam seals and belt steam seals according to their installation positions. The basic structure of the steam seal mainly includes three parts: steam seal body, spring leaf and steam seal ring. The flange of the steam seal ring is installed in the corresponding groove of the steam seal body, and the spring leaf maintains the position of the steam seal ring. Once it collides with the rotor, the steam seal ring can rebound to ensure the safe operation of the unit. As an important component of the steam seal, the structure of the spring leaf has an important impact on the steam seal effect and the safe operation of the entire unit. As shown in the attached figure Figure 1 As shown, in the prior art, the steam seal spring sheet is a diamond-shaped spring sheet, which is clamped between the steam seal ring and the steam seal body. The diamond-shaped spring sheet has a large contact area with the steam seal body and a large friction force, which increases the resistance of the steam seal ring to retreat when the moving and static parts collide and rub. In addition, the diamond-shaped spring sheet adopts a variable cross-sectional shape, which leads to uneven force and can support the steam seal ring with a weight between 90 and 125N. When used in medium and large steam turbines, it is very easy to cause the diamond-shaped spring sheet to break, causing the steam seal ring to lose its retreat. On the one hand, the steam seal teeth and the rotor collide and rub for a long time, resulting in an increase in the steam seal leakage. On the other hand, water vapor enters the front and rear boxes axially to emulsify the oil, reducing the lubrication performance. At the same time, when the oil source is shared with the regulating system, it causes blockage and rust in the regulating system, resulting in abnormal operation of the unit.

[0003] Therefore, in view of the current status of the above-mentioned prior art, it is an urgent problem to develop a spring sheet for steam seal and a steam seal. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a steam seal spring sheet and a steam seal, which can reduce the contact area between the spring sheet and the steam seal body, reduce friction, and at the same time enhance the strength of the steam seal spring sheet, making it less likely to break and extending its service life.

[0005] The technical scheme adopted by the present application to solve the above technical problems is: a spring sheet for a steam seal, the spring sheet for the steam seal comprises a support body, the support body is in an arch shape, both ends of the support body are respectively provided with a fixed support leg and a sliding support leg, a clamping groove is arranged on the fixed support leg, and the clamping groove is used for positioning the fixed support leg. The support body in an arch shape is in contact with the steam seal body to reduce friction, the resistance of the steam seal ring when the moving and static parts collide is reduced, the spring sheet has good retreat performance, the actual yield strength of the arch-shaped structure is also enhanced, and the spring sheet is suitable for small, medium and large steam turbines and is not prone to breaking.

[0006] Further, the fixed support leg is in a plate shape, and the fixed support leg and the support body are connected through a reinforcing arc. The connection strength of the support body and the fixed support leg can be enhanced to avoid stress concentration and breaking.

[0007] Further, the sliding support leg is in an arc shape, and the surface of the trough of the sliding support leg is used for abutting against the steam seal ring. The arc-shaped structure reduces the contact area with the steam seal ring, and further reduces the retreat resistance.

[0008] Further, the support body, the fixed support leg and the sliding support leg are in an integral molding structure. The integral molding structure is beneficial to enhancing the overall strength and preventing breaking.

[0009] Further, the spring sheet for the steam seal is made of GH136 material. The spring sheet for the steam seal has high elasticity, fatigue strength and high-temperature resistance, and is suitable for use in steam turbines.

[0010] Further, a self-lubricating friction-reducing layer is arranged on the surface of the spring sheet for the steam seal. The self-lubricating friction-reducing layer can reduce friction and further reduce the retreat resistance.

[0011] Further, the fixed support leg, the support body and the sliding support leg have the same width, the fixed support leg, the support body and the sliding support leg have the same thickness H, and 1.8mm≤H≤5.7mm. The equal-section structure can avoid uneven stress and breaking.

[0012] The present application also provides a steam seal, which comprises a steam seal ring and a steam seal body, and further comprises the spring sheet for the steam seal, a flange is arranged on the circumferential surface of the steam seal ring, a groove is arranged on the inner circular surface of the steam seal body, the flange can be clamped in the groove, the fixed support leg and the sliding support leg are arranged on the flange, a limiting piece is arranged on the flange, the limiting piece can be clamped in the clamping groove, the sliding support leg can slide along the flange, and the top of the support body abuts against the steam seal body. The limiting piece and the clamping groove are used to facilitate the installation of the spring sheet and achieve good limiting effect.

[0013] Further, the groove has a groove width L1, the fixed support leg and the sliding support leg have a width L2, and 1.5mm < L1-L2 < 2mm. By limiting the groove size, the spring sheet is prevented from being stuck in the installation groove due to a too small gap, and the spring sheet is also prevented from moving left and right in the groove due to a too large gap, so that the steam seal ring cannot be uniformly retracted.

[0014] Further, the flange is provided with an installation groove, one end of the installation groove is provided with the limiting piece, the fixed support leg and the sliding support leg are arranged in the installation groove, the sliding support leg can slide along the groove bottom of the installation groove, the installation groove has a groove width L3, the fixed support leg and the sliding support leg have a width L2, and 1.5mm < L3-L2 < 2mm. By opening the installation groove, the installation and use flexibility of the spring sheet is improved, and in the case of a wide groove, the gap can also be ensured to be within an appropriate range, so that the spring sheet is prevented from being stuck or moving left and right.

[0015] From the above technical solutions, the present application has the following advantages:

[0016] The present application provides a spring sheet for steam seal and a steam seal. The arch-shaped support body is in contact with the steam seal body to reduce friction, the resistance of the steam seal ring to retract when the dynamic and static parts collide is reduced, the retraction performance is good, the arch-shaped structure also enhances the actual yield strength of the support, is suitable for small, medium and large steam turbines, and is not easy to break; the reinforced arc transition can enhance the connection strength of the support body and the fixed support leg, and prevent stress concentration from causing breakage; the arc-shaped movable support leg and the self-lubricating friction reduction can reduce the friction with the steam seal ring, and further reduce the retraction resistance; the equal cross-section structure can prevent uneven stress from causing breakage; the limiting piece and the clamping groove can be matched to facilitate the installation and fixation of the spring sheet; the relationship between L1 and L2 can prevent the spring sheet from being stuck in the installation groove due to a too small gap, and prevent the spring sheet from moving left and right in the installation groove due to a too large gap, so that the steam seal ring cannot be uniformly retracted. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Figure 1 It is a structure schematic diagram of a diamond-shaped spring sheet.

[0019] Figure 2 It is a structure schematic diagram of a spring sheet for steam seal in the first specific embodiment of the present application Figure 1 .

[0020] Figure 3 Structure diagram of spring sheet for steam seal in the embodiment one of the present application Figure 2 .

[0021] Figure 4 Structure diagram of steam seal in the embodiment one of the present application Figure 1 .

[0022] Figure 5 Structure diagram of steam seal in the embodiment one of the present application Figure 2 .

[0023] Figure 6 Structure diagram of steam seal in the embodiment two of the present application

[0024] In the figure, 1, fixed support leg, 2, support body, 3, sliding support leg, 4, clamping groove, 5, steam seal body, 6, diamond spring sheet, 7, flange, 8, mounting groove, 9, steam seal ring, 10, limiting piece, 11, recess. EMBODIMENT

[0025] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the technical solutions in the present application will be described clearly and completely below by combining the drawings in the embodiment. Obviously, the following described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present patent, all the other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present patent. EMBODIMENT ONE

[0027] As Figures 2-3As shown, this specific embodiment provides a spring sheet for steam seal, including a support body 2, a fixed support foot 1 and a sliding support foot 3; the support body 2 is arch-shaped, and a fixed support foot 1 and a sliding support foot 3 are respectively provided at both ends of the support body 2. The support body 2, the fixed support foot 1 and the sliding support foot 3 are an integrally formed structure with higher strength. The support body 2 adopts an arch structure. Compared with the diamond structure, on the one hand, it reduces the contact area between the support body 2 and the steam seal body 5, reduces friction, and ensures yieldability. On the other hand, the support body 2 with an arch structure has a high yield strength and can withstand greater pressure, ensuring a longer service life without deformation and fracture; the fixed support foot 1 is a plate-like structure, and the fixed support foot 1 and the support body 2 are connected by a reinforcing arc transition. The reinforcing arc can avoid stress concentration and prevent fracture at the connection. A card slot 4 is provided on the fixed support foot 1, and the card slot 4 is used to position the fixed support foot 1. The card slot 4 includes an entry end and a card connection end , the width of the entry end is smaller than the diameter of the clamping end; the sliding support foot 3 is an arc-shaped structure, and the surface of the sliding support foot 3 at the trough is used to abut against the steam seal ring 9, further reducing the friction generated by the spring leaf and the steam seal ring 9 when the spring leaf is deformed, ensuring better yieldability; the support body 2, the fixed support foot 1 and the sliding support foot 3 are all made of GH136 material, and a self-lubricating anti-friction layer is provided on the surface of the support body 2, the fixed support foot 1 and the sliding support foot 3. The self-lubricating anti-friction layer adopts a porous self-lubricating powder metallurgy anti-friction material with good friction reduction performance, reducing the friction between the spring leaf and the contact position, and further ensuring better yieldability; the fixed support foot 1, the support body 2 and the sliding support foot 3 have the same width, and the fixed support foot 1, the support body 2 and the sliding support foot 3 have the same thickness H, 1.8mm≤H≤5.7mm, which realizes that the spring has an equal cross-sectional structure, which can ensure uniform force and is not easy to deform or break.

[0028] like Figure 4 and Figure 5 As shown, this specific embodiment also provides a steam seal, including a steam seal ring 9 and a steam seal body 5, and also includes the above-mentioned steam seal spring sheet, a flange 7 is provided on the steam seal ring 9, and the cross section of the flange 7 is an inverted convex shape, a groove 11 is provided on the inner circular surface of the steam seal body 5, and the cross section of the groove 11 is an inverted convex shape, the flange 7 can be clamped in the groove 11, and a limiting member 10 is provided on the flange 7. In this specific embodiment, the limiting member 10 is a screw, and the fixed support leg 1 and the sliding support leg 3 are both provided on the flange 7. The limiting member 10 is clamped with the clamping groove 4 to limit the fixed support leg 1, and the top of the support body 2 abuts against the steam seal body 5; the groove width of the groove 11 is L1, and the width of the fixed support leg 1 and the sliding support leg 3 are both L2, 1.5mm <L1-L2<2mm,避免间隙过小导致弹簧片在凹槽11内卡涩问题,又防止间隙过大弹簧片在凹槽11内左右移动,导致汽封圈9不能实现均匀退让。 Specific implementation method 2

[0030] As Figure 6 shown in the specific embodiment, the specific embodiment provides a steam seal, the specific embodiment is basically same with the steam seal structure in the specific embodiment one, the difference lies in: the circumferential surface of the flange 7 is provided with the installation groove 8, one end of the installation groove 8 is provided with the limiting piece 10 also using screw, the fixed support leg 1 and the sliding support leg 3 are all arranged in the installation groove 8, the limiting piece 10 can be clamped in the clamping groove 4;The slot width of the installation groove 8 is L3, 1.5mm < L3-L2 < 2mm;When the difference between the width of the recess 11 and the width of the spring piece exceeds 2mm, the installation groove 8 is arranged on the flange 7, so that the difference between the width of the installation groove 8 and the width of the spring piece meets the requirement, and the application range of the spring piece is increased.

[0031] From the above specific embodiment, the present application has the following beneficial effects:

[0032] 1, by the contact of the arch-shaped support body 2 and the steam seal body 5, the friction force is reduced, the resistance of the steam seal ring 9 is reduced when the moving and static parts collide, and the spring piece has good retreat performance, and the arch-shaped structure also enhances the actual yield strength of the support, which is suitable for small, medium and large steam turbines, and is not easy to break;

[0033] 2, by using the reinforced arc transition, the connection strength of the support body 2 and the fixed support leg 1 can be enhanced, and the fracture caused by stress concentration can be avoided;By setting self-lubricating friction reduction, the friction between the moving support leg and the steam seal ring 9 can be reduced, and the retreat resistance is further reduced;

[0034] 3, by using the equal cross-section structure, the uneven stress and easy breaking can be avoided;By the cooperation of the limiting piece 10 and the clamping groove 4, the spring piece can be conveniently installed and fixed;

[0035] 4, by setting the relationship between L1 and L2, the problem of spring piece jamming in the recess 11 caused by too small gap can be avoided, and the problem of spring piece moving left and right in the recess 11 caused by too large gap can be prevented, so that the steam seal ring 9 cannot realize uniform retreat;

[0036] 5, by setting the installation groove 8 on the flange 7, the gap between the spring piece and the two side parts after installation can be controlled, and the application range of the spring piece is improved.

[0037] The terms "upper", "lower", "outer", "inner" and the like (if any) in the specification and claims of the present application and the above-described drawings are used to distinguish relative positions, and do not necessarily give a qualitative meaning. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0038] The foregoing description of the disclosed embodiments enables one skilled in the art to make or use the application. Numerous modifications of those embodiments can be apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without the use of the innovation falling outside the spirit and scope of the application. Therefore, the application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steam seal comprising a steam seal ring (9) and a steam seal body (5), characterized in that: It also includes a spring sheet for steam seal, the spring sheet for steam seal includes a support body (2), the support body (2) is arch-shaped, and fixed support feet (1) and sliding support feet (3) are respectively provided at both ends of the support body (2), the fixed support feet (1) are provided with a card slot (4), and the card slot (4) is used to position the fixed support feet (1), the fixed support feet (1) are plate-shaped structures, the fixed support feet (1) and the support body (2) are connected through a reinforcing arc transition, the sliding support feet (3) are arc-shaped structures, and the surface of the sliding support feet (3) at the trough is used to abut against the steam seal ring (9); The support body (2), the fixed support leg (1) and the sliding support leg (3) are an integrally formed structure; A self-lubricating and anti-friction layer is provided on the surface of the steam seal spring sheet; A flange (7) is provided on the circumferential surface of the steam seal ring (9), a groove (11) is provided on the inner circumferential surface of the steam seal body (5), the flange (7) can be clamped in the groove (11), the fixed support leg (1) and the sliding support leg (3) are both provided on the flange (7), the flange (7) is provided with a limiting member (10), the limiting member (10) can be clamped in the clamping groove (4), the sliding support leg (3) can slide along the flange (7), and the top of the support body (2) is in contact with the steam seal body (5); The flange (7) is provided with a mounting groove (8), one end of the mounting groove (8) is provided with the limiting member (10), the fixed support leg (1) and the sliding support leg (3) are both provided in the mounting groove (8), the sliding support leg (3) can slide along the bottom of the mounting groove (8), the width of the mounting groove (8) is L3, the width of the fixed support leg (1) and the sliding support leg (3) are both L2, 1.5mm <L3-L2<2mm。 2. The steam seal according to claim 1, characterized in that The steam seal spring sheet is made of GH136 material.

3. The steam seal according to claim 1, characterized in that The fixed support leg (1), the support body (2) and the sliding support leg (3) have the same width, and the fixed support leg (1), the support body (2) and the sliding support leg (3) have the same thickness H, which is 1.8 mm ≤ H ≤ 5.7 mm.

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