CN1218535A

CN1218535A - Seal arrangement and steam turbine

Info

Publication number: CN1218535A
Application number: CN97194678A
Authority: CN
Inventors: 阿克塞尔·伦伯格
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1996-05-15
Filing date: 1997-05-12
Publication date: 1999-06-02
Also published as: PL329690A1; KR20000010952A; DE19619725A1; CZ296798A3; EP0954681A1; JP2000510214A; WO1997043521A1

Abstract

The invention relates to a seal arrangement (18) to seal off a first area (19) from a second area (20). Fluid (17) can flow through each area (19, 20) the pressure of which can be maintained on a different level. The seal arrangement comprises a rotary component (12, 10) rotating about a main axis (14) and a stationary component (11, 13). One of the components (12, 13) comprises a recess (16a, 16b) running in the direction of the periphery and the other component (11, 10) an end piece (5). Adjoining to the end piece (5) follows a sealing web (6) with a crosswise arranged area (8) running essentially parallel to the main axis (14) at a distance from the end piece (5), which protrudes radially into the recess (16a, 16b) with the recess (16a, 16b) being geometrically similar to the sealing web (6).

Description

Sealing configuration and steam turbine

The present invention relates to a kind of sealing configuration, it is used for first area and second area that fluid can different pressures flows through are separated sealing, and this sealing configuration is used in especially to have along in the steam turbine of the rotor of turbine axis orientation and inner casing.In addition, the invention still further relates to a kind of steam turbine.

In patent EP0611905A1, put down in writing a kind ofly between the chamber of different pressures, particularly between the chamber of the different pressures of fluid machinery, realize the device of non-contact sealing.In this fluid machinery, must between the chamber of different pressures, be furnished with suitable axle envelope.Described device is a labyrinth-type excluder, wherein, has constituted stepped labyrinth gap between revolving part and fixed block, in labyrinth clearance, is provided with labyrinth plate on revolving part and fixed block, therefore can improve flow through the churning of medium.Labyrinth plate between fixed block and the revolving part will be arranged closer to each otherly as far as possible, makes only to have very little axial clearance.The labyrinth plate radial extension makes that the labyrinth plate of adjacent two-stage is overlapped.One group of labyrinth plate can insert in the corresponding groove by means of the tenon silk.

In the paper " measure of modernization of steam turbine element and life-saving " that the 116th page of VGB power plant technology the 71st volume, the 2nd phase in 1991 are delivered in to 122 pages, the seal arrangement of the different types that is applied to the steam turbine blade has been described at D.Bergmann.M.Jansen and H.Oeynhausen.Figure 13 of paper shows steam earial drainage relative between guide vane and turbine rotor.In some forms of implementation, on guide vane, be provided with groove herein.For so-called diaphragm seal-diaphragm seal-seal arrangement (Spitze-Spitze-Dichtung), can realize minimum relative steam leakage, wherein, in the axial direction, on turbine rotor and guide vane, alternately be provided with diaphragm seal.By improving the clearance seal between turbine rotor and the guide vane, can reduce the loss in efficiency of steam turbine device.

Patent DD-PS5380 relates to a kind of labyrinth gap seal arrangement, and in particular for the labyrinth gap seal arrangement of turbine engine or centrifugal compressor, it has mutually opposed and coefficient Sealing.One flexible Sealing is made by stalloy, and the centrifugal force of these stalloy utilizations itself perhaps by the effect of high-pressure medium, is close on the convex shoulder of annular groove.Between adjacent annular groove, charge into a plane Rectifier plate.In the abridgments of specifications of Japanese M-133,29 days the 6th May of nineteen eighty-two volume the 93rd phase JP-A57-28810, the sealing configuration between a kind of guide vane of and each interval adjacent a moving vane and two has been described.At this, this moving vane has a ring-type convex shoulder respectively at the two ends of leaf area.On the axially-extending part of guide vane, be provided with the seal element that also adjoins with it towards moving vane.Publish Berlin VEB technology publishing house in 1973, by " research of axial turbine level and calculating " book that Dejc and Trojanovskij showed in, in chapters and sections 7.6.4.3 " influence of the overlapping and band of blade ", show all sealing systems between nozzle blade cascade and turbine rotor.In a form of implementation, this nozzle blade cascade has the T-shaped seal element of a cross section, and its inserts in the rectangular substantially rotor.

The objective of the invention is to, a kind of sealing configuration that reduces escape of liquid amount between revolving part and the fixed block is provided, its two region separation that hydrodynamic pressure is different is opened.Another object of the present invention is to, a kind of steam turbine with this sealing configuration is provided.

With a sealing configuration first area and the second area that fluid can different pressures flows through separated sealing, according to the present invention, this can utilize a kind of like this sealing configuration to realize, it has one can be around the parts and a fixed component of main axis rotation, at this, one of them parts has a circumferential recess, and another parts then have an end, and a sealing plate adjoins with this end.The sealing plate have one be arranged essentially parallel to main shaft, with the end transverse area of certain intervals distance is arranged, and radially insert non-contiguously in the groove, wherein, this groove and sealing plate geometric similarity.

The sealing plate is preferably in the longitudinal axis and fluid is gone in the cutting plane of flow path direction formation, has one and for example is T type or L shaped cross section.Described vertical with the longitudinal axis basically, be positioned at the transverse area of (fluid) flow direction, by installing the groove of any cross section, for example rectangle or semicircular groove form.Such advantage is, is installed in the sealing plate on parts, the particularly turbine blade, goes into to have a groove on the flow path direction at fluid, and then fluid by this groove, and then passes through sealing plate when flowing through turbine blade, improve the generation of eddy current, perhaps produced a backflow of increasing flow resistance.Fixed component and/or rotatable parts, preferably a turbine blade along longitudinal axis orientation.In turbine blade, on the profile zone, be connected with a sealing plate, its part is in y direction, a part is vertical with the longitudinal axis basically, with the fluid that flows through turbine blade to go into flow path direction corresponding, at this, the end in transverse area and profile zone is at regular intervals, and sealing plate is arranged on the end in profile zone.

Turbine blade with the relative end in its blade root zone, have one may hettocyrtosis cover plate, sealing plate is arranged on this cover plate, particularly is welded on this cover plate, is perhaps milled out by this cover plate.On the rotor of turbine, especially steam turbine, in the turbine blade of circumferential adjacent layout, the cover plate of turbine blade constitutes a circular band, is arranged in some circumferential sealing plates substantially on the plane perpendicular to the main shaft of the rotor with circular cross section, constitutes a circular sealing strip.Be basically perpendicular to circumferential transverse area by these sealing plates, formed sealing strip has improved flow resistance, and and then has reduced to comprise the turbine blade of guide vane and moving vane and the earial drainage between inner casing or the turbine rotor.In addition, the raising of flow resistance can utilize transverse area to realize, because it has formed a circular axial notch, this groove can make fluid diverting and produce eddy current.

On the sealing plate, be provided with a labyrinth plate at least, preferably a plurality of labyrinth plates.These/this labyrinth plate is along the y direction orientation.Thus, outside sealing plate, can form a labyrinth sealing in addition, as EP0611905A1 or above illustrated in the paper quoted.

Turbine blade preferably is meant steam turbine, particularly presses in one and/or the moving vane or the guide vane of a low pressure turbine section.By employing have sealing plate according to the invention guide vane and moving vane, can reduce the steam earial drainage in the steam turbine, particularly increase work efficiency thus at low pressure turbine Duan Zhongke.

The present invention is achieved like this about the purpose of steam turbine aspect, promptly, a rotor and/or an inner casing that extends along the turbine axis respectively, upwards has an annular recess in week, so that the sealing plate of sealing plate, especially turbine blade, insert non-contiguously, insert groove non-contiguously by sealing plate, can make the steam of in steam turbine, carrying obtain a high flow resistance, can reduce steam leakage significantly thus.This not only is applicable between guide vane and the rotor, between moving vane and the inner casing and the sealing between rotor and the inner casing, but also be applicable to the sealing of axle.

Improve flow resistance for further, and produce eddy current and recirculating zone in addition again, the stretching, extension of groove is parallel to the turbine axis in the axial direction diametrically perpendicular to the turbine axis.Thereby groove can have T shape, L shaped or similar profile in perpendicular to circumferential cross section, with sealing plate the cross-sectional profile geometric similarity.

In groove, be provided with at least one and be positioned in the radial direction labyrinth plate, preferably a plurality of labyrinth plates that are positioned in the radial direction.Thus, can form an additional labyrinth sealing, and thereby further improve flow resistance.At this, each labyrinth plate constitutes a labyrinth plate band at extending circumferentially.

In groove, preferably insert a sealing plate that is located substantially on circumferential turbine blade.The sealing plate is preferably made T shape or L shaped.Therefore, in groove, flow direction can improve flow resistance thus significantly through two to four about 180 ° turning to, and thereby has reduced the steam earial drainage significantly.Particularly in middle pressure or low pressure turbine section, can increase work efficiency like this.

By the accompanying drawing illustrated embodiment, sealing configuration and steam turbine are further described below, in the accompanying drawing:

Fig. 1 is the local diagrammatic sketch of steam turbine longitudinal section;

Fig. 2 is the amplification diagrammatic sketch according to the sealing configuration of Fig. 1.

Fig. 1 illustrates the local diagrammatic sketch of the longitudinal section of steam turbine not shown further in the lump, and this steam turbine has an inner casing 13 and and is arranged in rotor 12 in the inner casing 13.Inner casing 13 and rotor 12 be along turbine axis 14 orientations, and on week or the periphery, upwards have

annular groove

16a, 16b in week in it is circular.In steam turbine, be furnished with a plurality of turbines blade 1,, for the purpose of diagrammatic sketch is clear, only show guide vane 11 that is fixed on the inner casing 13 and the moving vane 10 that links to each other with rotor 12 herein.Each turbine blade 1 all has a blade root zone 3, utilizes it, and blade anchor fixes on inner casing 13 or the rotor 12.Turbine blade 1 is along the longitudinal axis 2 direction orientations.On the longitudinal axis 2 directions, be used for the profile zone 4 that vapor stream 17 turns to and be connected blade root zone 3.Profile zone 4 has an end 5 relative with blade root zone 3, which is provided with cover plate 7.Circumferentially be fixed on the

turbine blade

10,11 on rotor 12 or the inner casing 13, constitute a circular leaf grating thus, cover plate 7 constitutes a circular band within it.On the longitudinal axis 2 directions, on end 5, be provided with a sealing plate 6, it is at cover plate 7 upper edge extending circumferentiallies.The transverse region 8 that sealing plate 6 has is one 5 at regular intervals with the end, be substantially perpendicular to the longitudinal axis 2.In transverse region 8 and end 5, especially and between the cover plate 7, form a groove 21 along extending circumferentially thus.This groove can have a rectangular cross section, under present case by the T shape structure of sealing plate 6 determined, also can be according to the production method of transverse area 8, for example also semicircular.Because the T shape profile of sealing plate 6 forms a groove 22 along extending circumferentially respectively in the both sides of the longitudinal axis 2.Sealing plate 6 contactlessly inserts separately in corresponding grooves 16a, the 16b.At this, the transverse dimension of transverse region 8 will be set like this, that is, make sealing plate 6 to insert or to take out in separately groove 16a, 16b afterwards.This point is advantageous particularly when one of assembling axially can steam turbine divided into two parts for example, because assembling work is very simple.The shape of

groove

16a, 16b and sealing plate 6 are complementary, and particularly can be similarly T shape, and, on turbine spindle 14 directions, have circular groove 21 corresponding to transverse area 8.In

groove

16a, 16b, on y direction, be provided with two labyrinth plates relative with transverse area 8.In addition, on the interior week of the periphery of rotor 12 and inner casing 13, equally on the longitudinal axis 2 directions, be provided with a labyrinth plate 9 relative separately with cover plate 7.

Insert by sealing plate 6 in the groove 16b of the groove 16a of rotors 12 or inner casing 13, between moving vane 10 and inner casing 13, and between guide vane 11 and rotor 12, avoided leaked steam by directly flowing through a radial clearance in the vapor stream 17.Exactly, between fixed block (being guide vane 11 or inner casing 13) and revolving part (being rotor 12 or moving vane 10),, leaked steam stream is repeatedly turned to, turn to 4 times at least about 90 ° by inserting the sealing plate 6 among groove 16a, the 16b.Thus, along with between the fixed block of steam turbine and revolving part, generating vortex and recirculating zone, improved flow resistance significantly.Utilization has the sealing plate 6 of transverse area 8 and groove 16a, the 16b that is complementary with sealing plate 6 shapes, and leaked steam flows about 180 ° and turns to 4 times.This makes flow resistance significantly improve again, and then has reduced the steam earial drainage.Utilize

groove

16a, 16b interior labyrinth plate 9 and other labyrinth plate 9, can further reduce steam leakage towards cover plate 7 towards transverse area 8.Equally also can constitute whole sealing labyrinths, wherein, on cover plate 7 and/or transverse area 8, be provided with labyrinth plate 9 equally by labyrinth plate 9.

By means of Fig. 2, describe a kind of with the sealing configuration 18 of first area 19 with second area 20 parting seals.Fig. 2 shows the local diagrammatic sketch of steam turbine shown in Figure 1 along the longitudinal section of main shaft 14 with the ratio of amplifying.Reference character identical among Fig. 2 and Fig. 1 has same meaning, just in this point, sees also the explanation to Fig. 1.(Fig. 2) exemplarily described sealing configuration 18, it will have the first area 19 of high steam pressure and be in having than the second area of low vapor pressure of sealing configuration 18 downstreams separates.Sealing configuration 18 comprises as the inner casing 13 of fixed block with as the moving vane 10 of revolving part.Similar with it, as to be regarded as sealing configuration 18 comprises guide vane 11, rotor 12 and be located immediately at sealing configuration between inner casing 13 and the rotor 12 in axle envelope scope.Rotary component, promptly moving vane 10, have a sealing plate 6, and it contactlessly inserts in the groove 16b that makes progress in 13 weeks of inner casing in the radial direction.Sealing plate 6 has and one is positioned at major axes orientation, just is positioned at the transverse area 8 of turbine axis 14 directions.This transverse area and cover plate 7 constitute one along groove 22 extending circumferentially, axial depression.Because the profile of sealing plate 6 is T-shaped, constitute 22, one of two such grooves altogether towards zone 19, another is towards zone 20.Groove 16b has and groove 22 corresponding circular grooves 21, and it and transverse area 8 are complementary.Between first area 19 and second area 20, do not pass the vapor stream 17 in blade profile zone 4, just the steam earial drainage will flow through groove 16b.Thus, the steam earial drainage will turn to 4 times at least, and particularly about 180 ° turns to, and makes when flowing through groove 16b, very high flow resistance occurs.This makes the throughput of steam earial drainage significantly reduce, and thereby has improved the working efficiency of steam turbine.

Outstanding part of the present invention is, is the sealing between the different pressures zone of improving different pressures zone, especially steam turbine, and fixed element inserts in the groove of rotatable member, and perhaps situation is opposite.Steam earial drainage between the different pressures zone must pass groove thus, and wherein, flowing repeatedly turns to, and flow resistance is significantly improved.Thus, to the excellent sealing of steam turbine vane group, perhaps, lay a solid foundation to excellent sealing by the axle of drawing in the housing.Preferably insert one and be positioned at circumferential sealing plate in groove, make the steam earial drainage repeatedly turn to, flow resistance improves.Groove or sealing plate profile be preferably the T type, the steam earial drainage is turned to repeatedly for about 180 °.Flow resistance improves with turning to explicitly, and the steam earial drainage is obviously reduced.Also can reduce the steam earial drainage in addition by the labyrinth sealing that employing has a labyrinth plate.By adopting sealing plate to insert the sealing configuration of groove, can improve being used for reducing steam turbine, the clearance seal of the gap loss in especially middle pressure or the low pressure turbine section is correspondingly increased work efficiency.

Claims

1. sealing configuration (18) that first area (19) and second area (20) is separated sealing, fluid (17) can be crossed this zone (19 by different pressure flows, 20), sealing configuration has one can be around the parts (12 of main shaft (14) rotation, 10) and a fixed component (11,13), parts (12 wherein, 13) has a groove (16a along extending circumferentially, 16b), another parts (11,10) has an end (5), one sealing plate (6) adjoins with this end, the sealing plate has one and is basically parallel to main shaft (14) and has the transverse area (8) of a determining deviation with end (5), and, the sealing plate contactlessly radially inserts groove (16a, 16b), wherein, described groove (16a, 16b) with sealing plate (6) geometric similarity.

2. according to the described sealing configuration of claim 1 (18), wherein, (16a, 16b) is T-shaped substantially or L shaped for described sealing plate (6) and corresponding groove.

3. according to claim 1 or 2 described sealing configurations (18), it has along the directed turbine blade (1) of the longitudinal axis (2), it has moving vane zone (3), be connected with profile zone (4) in the longitudinal axis (2) direction on it, this profile zone has sealing plate (6) in the end (5) relative with blade root zone (3).

4. according to the described sealing configuration of claim 3 (18), wherein, be provided with a cover plate (7), which is provided with a sealing plate (6) in the end (5) of turbine blade (1).

5. according to claim 3 or 4 described sealing configurations (18), wherein, turbine blade (1) is the moving vane (10) or the guide vane (11) of steam turbine.

6. according to the described sealing configuration of above-mentioned each claim (18), wherein, in groove (16a, 16b), relatively be provided with a labyrinth plate (9) that is basically perpendicular to main shaft (14) with sealing plate (6).

7. according to the described sealing configuration of above-mentioned each claim (18), wherein, on sealing plate (6), be provided with radial labyrinth formula diaphragm seal (9).

8. steam turbine that has according to the described sealing configuration of above-mentioned each claim (18), it has a rotor (12) and an inner casing (13), they are respectively along turbine axis (14) orientation, wherein, rotor (12) and/or inner casing (13), circumferentially has annular groove (16a, 16b) on (15), so that sealing plate, especially a turbine blade (1) contactlessly inserts.

9. according to the described steam turbine of claim 8, wherein, described groove (16a, 16b) part upwards stretches in the footpath perpendicular to turbine axis (14), and part stretches axial the going up that is parallel to turbine axis (14).