CN114941551A

CN114941551A - Seal tooth structure for turbine

Info

Publication number: CN114941551A
Application number: CN202210676201.8A
Authority: CN
Inventors: 李若鹏; 张建华; 高寒
Original assignee: Huaibei Guoan Power Co ltd
Current assignee: Huaibei Guoan Power Co ltd
Priority date: 2022-06-15
Filing date: 2022-06-15
Publication date: 2022-08-26

Abstract

The application discloses a seal tooth structure for turbine, seal tooth structure includes brush silk bundle, bimetallic strip, sealed preceding baffle and sealed backplate, its characterized in that: the brush silk bundle with the bimetallic strip is followed the rotor circumference interval arrangement of turbine, brush silk bundle one end with bimetallic strip one end fixed connection forms the stiff end, the brush silk bundle other end with the bimetallic strip other end forms the free end, the upper and lower both sides of stiff end respectively with baffle before sealed with sealed backplate fixed connection, the free end extends and surpasss baffle before sealed with sealed backplate. Compared with the prior art: the sealing clearance of the structure can be automatically adjusted along with the temperature change, the problem of malignant friction heat generation is avoided, the safe operation of the turbine is ensured, the sealing clearance can be maintained at a small value, the sealing effect is greatly improved, and the service life of a product is prolonged.

Description

Seal tooth structure for turbine

Technical Field

The present application relates to turbine sealing technology, and in particular to a seal tooth structure for a turbine.

Background

At present, a plurality of seals are arranged in a turbine, a rotor rotates at a high speed during working, the seals belong to a stator, a good sealing state is kept between the stator and the rotor, adverse factors such as abnormal vibration of equipment and thermal bending of the rotor caused by frictional heat and the like which influence safe operation cannot be caused, at present, the seal teeth with small gaps in the operation of the turbine are most afraid of the time of the growth of the rotor, high-speed friction not only can cause abrasion to the seal teeth to increase the seal gaps permanently, but also can cause the thermal bending of the rotor caused by long-time friction to aggravate vibration and cause serious safety accidents such as machine jump, how to keep reasonable fit gaps and not aggravate mutual friction is always the largest problem in the industry, and the existing measures for avoiding a series of unsafe problems caused by frictional heat are mostly adopted for enlarging the seal fit gaps to reduce excessive frictional heat, however, if the sealing gap is too large, a part of the medium will flow through the gap without doing work, which becomes a loss, and the work output of the turbine will be reduced, thus seriously affecting the efficiency of the unit.

Disclosure of Invention

The technical problem to be solved by the present application is to overcome the above technical drawbacks and to provide a seal tooth structure for a turbine.

According to an aspect of the application, a sealed tooth structure for turbine, sealed tooth structure includes brush silk bundle, bimetallic strip, baffle and sealed backplate before sealed, brush silk bundle with the bimetallic strip is followed the rotor circumference interval arrangement of turbine, brush silk bundle one end with bimetallic strip one end fixed connection forms the stiff end, the brush silk bundle other end with the bimetallic strip other end forms the free end, the upper and lower both sides of stiff end respectively with baffle before sealed with sealed backplate fixed connection, the free end extends to surpass baffle before sealed with sealed backplate.

Preferably, the brush tows and the bimetallic strips are arranged in an inclined manner along the rotation direction of the rotor, the fixed end is far away from the rotor, and the free end is close to the rotor.

Preferably, the bimetal comprises a first metal sheet and a second metal sheet, the first metal sheet and the second metal sheet are fixedly connected along the thickness direction of the bimetal, the first metal sheet is far away from the rotor, the second metal sheet is close to the rotor, and the thermal expansion coefficient of the first metal sheet is smaller than that of the second metal sheet.

Preferably, the front sealing baffle and the rear sealing baffle are both of an annular structure, the inner diameter and the outer diameter of the front sealing baffle and the outer diameter of the rear sealing baffle are the same, and the front sealing baffle and the rear sealing baffle are arranged in an up-and-down alignment manner.

Preferably, one side of the sealing rear baffle facing the fixed end is uniformly provided with a plurality of annular grooves.

Preferably, the thickness of the brush wire bundle is 3-6 times of the thickness of the bimetallic strip.

Preferably, the fixed end is connected by high-energy beam welding.

Preferably, the fixed end is connected with the front sealing baffle and the rear sealing baffle in a high-energy beam welding manner.

Compared with the prior art, the application has the advantages that: according to the sealing tooth structure for the turbine, the brush filament bundles and the bimetallic strips are uniformly arranged at intervals, so that the brush filament bundles can play a sealing role, and the bimetallic strips can be bent and deformed when heat generated by friction is too high so as to drive the brush filament bundles to change the arrangement inclination angle and reduce the friction; the friction weakens or disappears, the temperature of the bimetallic strip is reduced, the bimetallic strip restores to the initial state, the brush wire bundle is driven to restore to the sealing state, the sealing gap of the structure can be automatically adjusted along with the temperature change, the problem of malignant friction heat generation is avoided, the safe operation of a turbine is guaranteed, the sealing gap can be maintained at a small value, the sealing effect is greatly improved, and the service life of a product is prolonged.

Drawings

FIG. 1 is a schematic structural view of a seal tooth configuration for a turbomachine in accordance with an embodiment of the present application;

FIG. 2 is a partial perspective view of a seal tooth configuration for a turbomachine in accordance with an embodiment of the present application.

FIG. 3 is a partial side sectional view of a seal tooth configuration for a turbomachine in accordance with an embodiment of the present application.

Reference numerals: the brush wire bundle comprises a brush wire bundle (1), a bimetallic strip (2), a sealing front baffle (3), a sealing rear baffle (4), a rotor (5), a first metal sheet (6), a second metal sheet (7) and an annular groove (8).

Detailed Description

In order to make the content of the present application more clearly understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

As shown in fig. 1 to 3, a seal tooth structure for a turbine includes a brush filament bundle 1, a bimetallic strip 2, a front seal baffle 3 and a rear seal baffle 4, the brush filament bundle 1 and the bimetallic strip 2 are uniformly arranged along the circumference of a rotor 5 of the turbine at intervals, wherein the thickness of the brush filament bundle 1 is 3 to 6 times of the thickness of the bimetallic strip 2, the arrangement can not only make the brush filament bundle 1 achieve an effective sealing effect, but also make the brush filament bundle 1 have a certain deformation capability, so that the bimetallic strip 2 can drive the brush filament bundle 1 to bend along with the brush filament bundle when bending deformation, and the brush filament bundle 1 and the bimetallic strip 2 are arranged in an inclined manner along the rotation direction of the rotor 5, one end of the brush filament bundle 1 is fixedly connected with one end of the bimetallic strip 2 to form a fixed end, the other end of the brush filament bundle 1 forms a free end with the other end of the bimetallic strip 2, the upper and lower two sides of the fixed end are respectively fixedly connected with the front seal baffle 3 and the rear seal baffle 4, the brush filament bundle 1 and the double metal sheets 2 can elastically give off when contacting with the turbine rotor 5, and the flexible tooth state is kept, on one hand, the double metal sheets 2 have supporting and protecting effects on the brush filament bundle 1, the brush filament bundle 1 is prevented from shaking at high frequency under the impact of air flow, a good stabilizing effect is achieved, and a good elastic state is not lost.

In one embodiment, referring to fig. 1 and 2, the bimetal 2 includes a first metal plate 6 and a second metal plate 7, the first metal plate 6 and the second metal plate 7 are fixedly connected along the thickness direction thereof, and the first metal plate 6 is far away from the rotor 5, the second metal plate 7 is close to the rotor 5, the thermal expansion coefficient of the first metal plate 6 is smaller than that of the second metal plate 7, through the different arrangement of the thermal expansion coefficients of the first metal plate 6 and the second metal plate 7, the turbine rotor 5 and the free end generate heat due to friction, so that after the temperature rises, the bimetal 2 is heated to expand and bend towards the first metal plate 6, and further the brush wire bundle 1 is driven to leave the surface of the rotor 5, the gap is increased, and further the friction is reduced, so that the friction and the aggravation of the friction and the vibration are avoided, after the friction force is reduced, no high temperature is generated by the friction, the temperature of the hot bimetal 2 is reduced, the brush filament bundle 1 is driven to recover to a perfect sealing state, so that the service life of the sealing teeth can be greatly prolonged, and the safety of the operation of the turbine is improved.

In one embodiment, referring to fig. 3, a plurality of annular grooves 8 are uniformly formed in one side of the sealing backplate 4 facing the fixed end, and through the arrangement of the plurality of annular grooves 8, not only can material loss be saved, but also when heat is generated through friction, the heat can be dissipated through the annular grooves 8, and damage to the sealing tooth structure is avoided.

In one embodiment, the fixed end is connected by high-energy beam welding, the fixed end is connected with the front sealing baffle 3 and the rear sealing baffle 4 by high-energy beam welding, and the high-energy beam welding has the advantages of high welding speed, small thermal deformation of a weldment, good welding seam performance, strong process adaptability, high purity of the welding seam and the like, and can better ensure the connection stability.

The working principle is as follows: when turbine rotor 5 moves, brush silk bundle 1 and bimetallic strip 2 not fixed connection's free end and rotor 5 contact, play the sealing effect, when the temperature that rotor 5 and free end friction produced was too high, high temperature can make bimetallic strip 2 crooked towards first sheetmetal 6, and then drive brush silk bundle 1 leave rotor 5 surface, the clearance increases, the friction weakens or disappears, the aggravation of bump grinding and vibration has been avoided, unusual vibration disappears the back, the high temperature that the friction produced has not been had, bimetallic strip 2 temperature reduction and then resume the original state gradually, drive brush silk bundle 1 and resume to intact encapsulated situation again, through this kind of can come from the sealed form of dynamic control along with the temperature change, can prolong the life of seal tooth greatly and also improve turbine operation's security simultaneously.

The above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, and not to limit the same. Although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A seal tooth structure for a turbine, the seal tooth structure comprising a brush bundle (1), a bimetallic strip (2), a seal front flap (3) and a seal back flap (4), characterized in that: brush silk bundle (1) with bimetallic strip (2) are followed rotor (5) circumference interval arrangement of turbine, brush silk bundle (1) one end with bimetallic strip (2) one end fixed connection forms the stiff end, brush silk bundle (1) other end with bimetallic strip (2) other end forms the free end, the upper and lower both sides of stiff end respectively with baffle before sealed (3) with sealed backplate (4) fixed connection, the free end extends and surpasss baffle before sealed (3) with sealed backplate (4).

2. A seal tooth construction for a turbine according to claim 1, wherein: the brush tows (1) and the bimetallic strips (2) are arranged in an inclined mode along the rotating direction of the rotor (5), the fixed ends are far away from the rotor (5), and the free ends are close to the rotor (5).

3. A seal tooth construction for a turbine according to claim 2, wherein: the bimetallic strip (2) comprises a first metal strip (6) and a second metal strip (7), the first metal strip (6) and the second metal strip (7) are fixedly connected along the thickness direction of the bimetallic strip, the first metal strip (6) is far away from the rotor (5), the second metal strip (7) is close to the rotor (5), and the thermal expansion coefficient of the first metal strip (6) is smaller than that of the second metal strip (7).

4. A seal tooth construction for a turbine according to claim 1, wherein: the front sealing baffle (3) and the rear sealing baffle (4) are both of annular structures, the inner diameter and the outer diameter of the front sealing baffle and the outer diameter of the rear sealing baffle are the same, and the front sealing baffle (3) and the rear sealing baffle (4) are aligned up and down.

5. A seal tooth construction for a turbomachine according to claim 4, wherein: seal backplate (4) orientation one side of stiff end evenly is provided with a plurality of annular groove (8).

6. A seal tooth construction for a turbine according to claim 1, wherein: the thickness of the brush filament bundle (1) is 3-6 times of that of the bimetallic strip (2).

7. A seal tooth construction for a turbine according to claim 1, wherein: the connecting mode of the fixed end is high-energy beam welding.

8. A seal tooth construction for a turbine according to claim 8, wherein: the fixed end is connected with the front sealing baffle (3) and the rear sealing baffle (4) in a high-energy beam welding mode.