CN104265378A - Novel hysteretic variable gap gland seal - Google Patents
Novel hysteretic variable gap gland seal Download PDFInfo
- Publication number
- CN104265378A CN104265378A CN201410510924.6A CN201410510924A CN104265378A CN 104265378 A CN104265378 A CN 104265378A CN 201410510924 A CN201410510924 A CN 201410510924A CN 104265378 A CN104265378 A CN 104265378A
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- packing
- gland seal
- segmental arc
- rotor
- steam
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- Turbine Rotor Nozzle Sealing (AREA)
- Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
Abstract
The invention discloses a novel hysteretic variable gap gland seal. The novel hysteretic variable gap gland seal comprises a gland seal body and a plurality of gland seal segmental arcs, wherein the surface of one side of the rotor toward to the gland seal body is provided with gland seal assembling slots, the gland seal segmental arcs are arranged in the gland seal assembling slots, and the adjacent gland seal segmental arcs are connected through springs; the steam inlet ends of all gland seal segmental arcs are provided with steam inlet slots, and the steam outlet side of the gland seal body is provided with at least one steam outlet hole. According to the hysteretic variable gap gland seal provided by the invention, the gland seal segmental arcs are closed under high load, and reopened at lower load, therefore gland seal teeth and a rotor cannot be touched and ground in the overall process of starting the turbine, the wear and deformation of the gland seal teeth can be prevented, the service life of the gland seal can be prolonged, the steam loss can be reduced, the unit output can be improved, and the efficiency of the turbine can be improved.
Description
Technical field
The present invention relates to the packing in steam turbine, gas turbine field, particularly relate to a kind of novel hysteresis formula variable gap packing.
Background technique
Packing is that the turbomachineries such as steam turbine reduce the critical component leaking vapour (gas) loss, improve energy conversion efficiency.Along with the progress of Turbine Blade Design technology, the energy conversion efficiency of blade grid passage has almost reached ultimate attainment.On the other hand, along with turbomachinery is towards the future development of Large Copacity high parameter, the reliability of unit and Economy are had higher requirement.Therefore, develop advanced packing, reduce leakage losses and improve packing working life, just becoming Large Steam Turbine Sets and raising the efficiency the key subjects needing to capture further.
Known turbine shaft passes cylinder place, movable vane top, is equipped with packing between dividing plate and rotor and between high intermediate pressure cylinder.From the angle improving turbine efficiency, need us to reduce Steam loss, at present, reducing labyrinth clearance is the topmost approach reducing Steam loss.For the fluid machinery as steam turbine, guarantee that its Security run is the major issue that we are concerned about all the time, particularly in steam turbine start-up course, because the temperature field of cylinder and rotor is uneven, upper and lower cylinder excessive temperature differentials and produce thermal distortion, labyrinth clearance is reduced or disappears, vibrate when also having rotor to cross critical speed of rotation and strengthen, and cylinder and rotor centering such as to be forbidden at the impact of factor, gland sealing gear is easy to touch mill with rotor, gland sealing gear is worn and torn, and sealing effect declines, and turbine efficiency reduces.In addition, touch mill and rotor local region also may be caused to produce amount of heat, likely make rotor produce permanent deformation, threaten the Security of unit operation.It is worthy of note, these unfavorable factor major parts above-mentioned all appear at steam turbine startup, low-load or lose suddenly in the process of load, therefore, the labyrinth clearance value that maintenance one is relatively large is under these conditions necessary for the damage alleviated packing, simultaneously, under middle high-load condition, little labyrinth clearance value should be maintained, to improve the Economy of unit.
Traditional packing mostly is labyrinth gland, and it is on rotor, process convex shoulder and groove, and packing adopts stage teeth structure to match with it, to create the flow channel of a high damping, low discharge coefficient between steam turbine sound part.Labyrinth ring is circumferentially generally divided into 4-12 packing segmental arcs, with adaptation level midsplit type cylinder body.Labyrinth gland (comb packing) is as main seal form a kind of in steam turbine, it utilizes a series of annular orifice and annular steam chest that are formed between packing and rotor, by repeatedly throttling and the dissipation effect generation damping of steam, reduce steam leakage vertically.Generally install a slice leaf spring at the back of each packing segmental arc of labyrinth gland, the pretightening force of leaf spring makes packing segmental arc radially inwardly near rotor, and the gap of gland sealing gear and rotor surface is minimally worth.When rotor occurs seriously to touch mill because of a variety of causes and gland sealing gear, this packing just has certain yielding ability, but the existence of the rigidity due to leaf spring, the yielding of packing segmental arc realizes under rotor and gland sealing gear exist the condition of larger contact force, if long-time running, all very major injury will be caused, the safety and economic operation of harm unit to packing and rotor.
In recent years, occurred a kind of novel variable gap packing, it along with the change of steam turbine main steam flow, can correspond to the change of the proportional pressure of working medium, automatically regulates labyrinth clearance value.Variable gap gland seal structure is substantially identical with traditional packing, just mills out on admission face and draws vapour groove together, its objective is and makes packing segmental arc backside pressure (labyrinth casing trench interiors pressure) equal steam admission side pressure.Variable gap packing eliminates the spring pressuring plate of traditional back up Reed type packing back of the body arc, between vertical section helical spring being arranged on two adjacent packing segmental arcs, the thrust of spring makes packing segmental arc be in position, maximum labyrinth clearance when not having vapor pressure, during unit starting, along with the increase of steam flow, the vapor pressure acting on each packing segmental arc back increases gradually, be enough to overcome spring force, during surface friction drag, packing segmental arc just starts to close gradually, until in running order, and all the time with rotor minimally gap width run, during shutdown, along with the minimizing of steam flow, packing segmental arc is under spring force away from rotor, radial clearance is made to reach maximum value.Generally be designed with the yielding distance of about 3mm between variable gap packing segmental arc and labyrinth casing, therefore gland sealing gear and rotor surface just have the gap of more than 3mm, when so just can ensure that packing segmental arc is opened, gland sealing gear not with Rub-impact.In addition, the gland sealing gear of variable gap packing generally still adopts traditional comb-shaped.
Existing variable gap packing achieves labyrinth clearance can be changed with the change of steam flow, the problem that after but it only address only steam flow arrival certain load, packing segmental arc closes, be that a kind of firm demand is closed, open type packing, steam load corresponding when also namely packing segmental arc closes and when reopening is equal.But due to the impact of various factors above mentioned, still likely touch mill with rotor at the existing variable gap packing of steam turbine starting period.
Summary of the invention
Goal of the invention: in order to overcome the deficiencies in the prior art, the invention provides a kind of novel hysteresis formula variable gap packing, make steam turbine gland sealing gear in whole start-up course all can not touch mill with rotor, avoid the wearing and tearing of gland sealing gear, distortion, decrease Steam loss, add unit output, improve the efficiency of steam turbine.
Technological scheme: for achieving the above object, technological scheme of the present invention is as follows:
A kind of novel hysteresis formula variable gap packing, comprise labyrinth casing and some packing segmental arcs, described labyrinth casing is provided with packing fitting recess towards the surface of rotor side, and described packing segmental arc is arranged in packing fitting recess, is connected between adjacent packing segmental arc by spring; Be provided with admission groove at the admission end of described each packing segmental arc, at least one vapor opening is set at the steam output side of described labyrinth casing.
Further, described vapor opening is uniformly distributed along described labyrinth casing steam output side circumferencial direction
Further, the two ends of described spring are arranged in the spring groove of adjacent packing segmental arc end, and described spring is helical spring or leaf spring.
Further, described rotor surface is provided with convex shoulder and groove, and described packing segmental arc is provided with gland sealing gear towards a side surface of rotor, described rotor and packing segmental arc Spielpassung.
Beneficial effect:
1, by arranging some vapor openings on labyrinth casing, make packing segmental arc just closed when middle high load, make steam turbine gland sealing gear in whole start-up course all can not touch mill with rotor, avoid the wearing and tearing of gland sealing gear, distortion, decrease Steam loss, add unit output, improve the efficiency of steam turbine.
2, due in start-up course, rotor can not produce thermal distortion, bending because touching mill, thus improves the Security of unit, decreases unit non-programmed halt number of times.
3, spring between variable gap packing segmental arc adopts the leaf spring that reliability is higher to connect, and overcomes and degradation shortcoming under creep stiffness occurs under normal spiral spring uses rear perishable fouling, life-span short, high temperature for a long time.
Accompanying drawing explanation
Below in conjunction with drawings and Examples, the invention will be further described.
Accompanying drawing 1 is packing segmental arc cross section structure schematic diagram of the present invention.
Accompanying drawing 2 is packing segmental arc of the present invention cross section structure schematic diagram when closing.
Accompanying drawing 3 is packing segmental arc of the present invention cross section structure schematic diagram when opening.
Accompanying drawing 4 is six packing segmental arcs of the present invention, four spring embodiment schematic diagram.
Accompanying drawing 5 is labyrinth casing of the present invention and vapor opening position view.
Accompanying drawing 6 is horizontal flange place of the present invention enlarged views.
Accompanying drawing 7 is four packing segmental arcs of the present invention, six spring embodiment schematic diagram.
Embodiment
Below in conjunction with accompanying drawing, the present invention is further described.
A kind of novel hysteresis formula variable gap packing, comprise labyrinth casing 200 and some packing segmental arcs 300, the quantity of packing segmental arc is generally between 4-12.Described labyrinth casing 200 is provided with T-shaped packing fitting recess towards the surface of rotor 600 side, described packing segmental arc 300 is arranged in corresponding packing fitting recess, connected by spring 400 between adjacent packing segmental arc 300, the two ends of described spring are arranged in the spring groove 330 of adjacent packing segmental arc 300 end, and described spring 400 is helical spring or leaf spring.Described rotor 600 surface is provided with convex shoulder and groove, and described packing segmental arc 300 is provided with gland sealing gear 310 towards a side surface of rotor 600, described rotor 600 and packing segmental arc 300 Spielpassung.Be provided with admission groove 320 at the admission end of described each packing segmental arc 300, arrange at least one vapor opening 210 at the steam output side of described labyrinth casing 200, described vapor opening is uniformly distributed along described labyrinth casing steam output side circumferencial direction.
The admission groove 320 of the admission end setting of described packing segmental arc 300, under making packing segmental arc 300 be in any state, packing segmental arc 300 back chamber communicates with steam admission side.The vapor opening 210 that described labyrinth casing 200 is arranged can make packing segmental arc 300 when completely not closed, the steam of packing segmental arc 300 back chamber to bleed steam output side by vapor opening 210, and when packing segmental arc 300 is in complete closed state, the steam of packing segmental arc 300 back chamber not to bleed steam output side by vapor opening 210.
The present invention is on the basis of existing variable gap packing, by offering some vapor openings 210 in labyrinth casing 200 steam output side position, the steam of packing segmental arc 300 chamber back indoor can be flowed out from vapor opening, thus reduce the vapor pressure of packing segmental arc chamber back indoor to a certain extent, when other conditions are constant, in steam turbine arrives before high load, packing segmental arc 300 is in open configuration always, gap between gland sealing gear 310 and rotor 600 is maximum, when steam turbine arrive in high load time, the temperature field of cylinder 100 and rotor 600 is also basicly stable, packing segmental arc 300 realizes closed under the effect of steam power.Once after packing segmental arc 300 closes, it reopens corresponding load will lower than load corresponding time closed, the implication of this namely concept of " hysteresis ".
For the present invention's novel hysteresis formula variable gap packing, during unit starting, before packing segmental arc 300 is completely not closed, due to the existence of pressure difference, have steam and flow into packing segmental arc 300 chamber back indoor from high pressure side through admission groove 320 continually, meanwhile, also have steam and flow into low voltage side from packing segmental arc 300 back chamber through vapor opening 210 continually.Now utilize several simple equation so that this physical process to be described:
According to hydromechanical knowledge, when fluid flow through orifices mouth, valve, the relation of flow and pressure reduction is: Δ p=fG
2, wherein f is a constant relevant with aperture, valve mechanism etc., and Δ p is the front and back pressure reduction of aperture, valve, and G is the flow by aperture, valve.
Before first supposing that packing segmental arc 300 is completely not closed, packing high side pressure is p
1, the pressure of packing segmental arc 300 back chamber is p
2, the pressure of low voltage side is p
3, admission groove 320 and vapor opening 210 are analogous to aperture or valve, suppose that the coefficient relevant to their structure is respectively f
1and f
2.
The process flowing into packing segmental arc 300 back chamber from high pressure side through admission groove 320 for steam has:
wherein G
1it is the steam flow by admission groove 320.The process flowing into low voltage side from packing segmental arc 300 back chamber through vapor opening 210 for steam has:
wherein G
2it is the flow by vapor opening 210.Due to G
1> 0, G
2> 0, so, p
1> p
2> p
3> 0, the pressure namely in the chamber of packing segmental arc 300 back between steam admission side pressure and steam output side pressure, and if not on labyrinth casing 200 punch, then have, p
1=p
2> p
3> 0.
Carry out force analysis to variable gap packing segmental arc to have:
Wherein, F is packing segmental arc spring force when closing, and α is packing segmental arc central angle, and the steam closing force of Δ p suffered by packing segmental arc 300 deducts the difference of opening force, f
rubfor the frictional force suffered by packing segmental arc 300.Obviously, on labyrinth casing 200 after steam output side punching, before packing segmental arc 300 is completely not closed, because the vapor pressure in the chamber of packing segmental arc back reduces, the steam pressure difference that each packing segmental arc 300 is born is reduced, and for a certain type packing, make it can just close required for the spring force F that overcomes and frictional force f
rubcertain, so only have as high side pressure p
1reaching higher numerical value just can make packing segmental arc 300 close, and also namely achieves the target that packing segmental arc 300 is closed at middle high load.
For structure and the setting type of the present invention's novel hysteresis formula variable gap packing, the present invention illustrates following two kinds:
The first: as shown in Figure 4, the whole circle of packing segmental arc 300 is evenly divided into six sections, and arranges 4 leaf springs on position as shown in Figure 4.At the two ends, left and right, horizontal flange place of cylinder, stopper 500 is installed, packing segmental arc 300 slip in a circumferential direction can be prevented, it also avoid the gravity of half-turn packing segmental arc 300 to the impact of lower branch packing segmental arc 300 simultaneously.Be evenly arranged 6 forms vapor opening 210 as shown in Figure 5 at labyrinth casing 200 steam output side, upper half-turn 3, lower branch 3, make each packing segmental arc all have a vapor opening 210 corresponding with it.
The second: as shown in Figure 7, the whole circle of packing segmental arc 300 is evenly divided into four sections, and every section is approximately 90 degree, and arranges 6 helical springs on position as shown in Figure 7.At the two ends, left and right, horizontal flange place of cylinder, stopper 500 is installed, packing segmental arc 300 slip in a circumferential direction can be prevented, it also avoid the gravity of half-turn packing segmental arc 300 to the impact of lower branch packing segmental arc 300 simultaneously.Be evenly arranged 4 forms vapor opening 210 as shown in Figure 7 at labyrinth casing 200 steam output side, upper half-turn 2, lower branch 2, make each packing segmental arc all have a vapor opening 210 corresponding with it.
It is worthy of note, embodiment 2 has respectively laid a helical spring on the upper and lower end face of stopper 500, the benefit done like this is the friction can eliminating packing segmental arc 300 end face and the upper and lower end face of stopper 500, decreases the resistance of closing in packing segmental arc 300 process.
The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.
Claims (4)
1. a novel hysteresis formula variable gap packing, it is characterized in that: comprise labyrinth casing (200) and some packing segmental arcs (300), described labyrinth casing (200) is provided with packing fitting recess towards the surface of rotor (600) side, described packing segmental arc (300) is arranged in packing fitting recess, is connected between adjacent packing segmental arc (300) by spring (400); Be provided with admission groove (320) at the admission end of described each packing segmental arc (300), at least one vapor opening (210) is set at the steam output side of described labyrinth casing (200).
2. a kind of novel hysteresis formula variable gap packing according to claim 1, is characterized in that: described vapor opening (210) is uniformly distributed along described labyrinth casing (200) steam output side circumferencial direction.
3. a kind of novel hysteresis formula variable gap packing according to claim 1, it is characterized in that: the two ends of described spring are arranged in the spring groove (330) of adjacent packing segmental arc (300) end, and described spring (400) is helical spring or leaf spring.
4. a kind of novel hysteresis formula variable gap packing according to claim 1, it is characterized in that: described rotor (600) surface is provided with convex shoulder and groove, described packing segmental arc (300) is provided with gland sealing gear (310) towards a side surface of rotor (600), described rotor (600) and packing segmental arc (300) Spielpassung.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410510924.6A CN104265378B (en) | 2014-09-28 | 2014-09-28 | A kind of novel hysteresis formula variable gap packing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410510924.6A CN104265378B (en) | 2014-09-28 | 2014-09-28 | A kind of novel hysteresis formula variable gap packing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104265378A true CN104265378A (en) | 2015-01-07 |
| CN104265378B CN104265378B (en) | 2015-12-30 |
Family
ID=52156936
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410510924.6A Expired - Fee Related CN104265378B (en) | 2014-09-28 | 2014-09-28 | A kind of novel hysteresis formula variable gap packing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104265378B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105351013A (en) * | 2015-11-10 | 2016-02-24 | 山东电力研究院 | Improved Brandon steam seal and application method of improved Brandon steam seal on turbine |
| CN114575935A (en) * | 2022-03-01 | 2022-06-03 | 西安热工研究院有限公司 | Self-adaptive flexible steam turbine shaft seal structure |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1172894A (en) * | 1996-08-05 | 1998-02-11 | 罗纳德·E·布兰登 | Sealing arrngement for fluid turbines |
| CN1070990C (en) * | 1993-01-04 | 2001-09-12 | Imo工业公司 | Retractible segmented packing ring for fluid turbines having gravity springs to neutralize packing segment weight forces |
| US6572115B1 (en) * | 2001-12-21 | 2003-06-03 | General Electric Company | Actuating seal for a rotary machine and method of retrofitting |
| EP1942294A1 (en) * | 2007-01-02 | 2008-07-09 | Siemens Aktiengesellschaft | Sealing device for a turbine |
| CN201236725Y (en) * | 2008-04-02 | 2009-05-13 | 王胜五 | Damping type self-regulation boundary steam seal |
| EP2213842A1 (en) * | 2009-01-29 | 2010-08-04 | Siemens Aktiengesellschaft | Hydrostatic seal assembly for a steam turbine |
-
2014
- 2014-09-28 CN CN201410510924.6A patent/CN104265378B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1070990C (en) * | 1993-01-04 | 2001-09-12 | Imo工业公司 | Retractible segmented packing ring for fluid turbines having gravity springs to neutralize packing segment weight forces |
| CN1172894A (en) * | 1996-08-05 | 1998-02-11 | 罗纳德·E·布兰登 | Sealing arrngement for fluid turbines |
| US6572115B1 (en) * | 2001-12-21 | 2003-06-03 | General Electric Company | Actuating seal for a rotary machine and method of retrofitting |
| EP1942294A1 (en) * | 2007-01-02 | 2008-07-09 | Siemens Aktiengesellschaft | Sealing device for a turbine |
| CN201236725Y (en) * | 2008-04-02 | 2009-05-13 | 王胜五 | Damping type self-regulation boundary steam seal |
| EP2213842A1 (en) * | 2009-01-29 | 2010-08-04 | Siemens Aktiengesellschaft | Hydrostatic seal assembly for a steam turbine |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105351013A (en) * | 2015-11-10 | 2016-02-24 | 山东电力研究院 | Improved Brandon steam seal and application method of improved Brandon steam seal on turbine |
| CN105351013B (en) * | 2015-11-10 | 2017-03-29 | 山东电力研究院 | A kind of improved brandon steam-glanding and its application process on steam turbine |
| CN114575935A (en) * | 2022-03-01 | 2022-06-03 | 西安热工研究院有限公司 | Self-adaptive flexible steam turbine shaft seal structure |
| CN114575935B (en) * | 2022-03-01 | 2024-01-23 | 西安热工研究院有限公司 | Self-adaptive flexible steam turbine shaft seal structure |
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| Publication number | Publication date |
|---|---|
| CN104265378B (en) | 2015-12-30 |
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Granted publication date: 20151230 Termination date: 20190928 |
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