EP0177408B1 - Dispositif de contrôle automatique du jeu d'un joint à labyrinthe de turbomachine - Google Patents

Dispositif de contrôle automatique du jeu d'un joint à labyrinthe de turbomachine Download PDF

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Publication number
EP0177408B1
EP0177408B1 EP85401863A EP85401863A EP0177408B1 EP 0177408 B1 EP0177408 B1 EP 0177408B1 EP 85401863 A EP85401863 A EP 85401863A EP 85401863 A EP85401863 A EP 85401863A EP 0177408 B1 EP0177408 B1 EP 0177408B1
Authority
EP
European Patent Office
Prior art keywords
annular
clearance
wearing
labyrinth
wipers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85401863A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0177408A1 (fr
Inventor
Robert Kervistin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Safran Aircraft Engines SAS
Original Assignee
Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA filed Critical Societe Nationale dEtude et de Construction de Moteurs dAviation SNECMA
Publication of EP0177408A1 publication Critical patent/EP0177408A1/fr
Application granted granted Critical
Publication of EP0177408B1 publication Critical patent/EP0177408B1/fr
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
    • F01D11/14—Adjusting or regulating tip-clearance, i.e. distance between rotor-blade tips and stator casing
    • F01D11/20—Actively adjusting tip-clearance
    • F01D11/24—Actively adjusting tip-clearance by selectively cooling-heating stator or rotor components
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/001—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between stator blade and rotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/02—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type

Definitions

  • the invention relates to an automatic control device in operation of the clearance of a labyrinth type turbomachine seal.
  • the seals between fixed parts and rotating parts of a turbomachine frequently use labyrinth type seals composed, on the one hand, of wipers-shaped elements, in variable number according to the operating conditions and according to various technological parameters, and, on the other hand, on the fixed part located opposite, of an element constituting a wear and sealing lining, called "abradable", that is to say usable by friction during possible contact with a wiper without causing significant damage thereto, this element being carried by an annular support connected to a fixed structure of the turbomachine.
  • Such seals can be arranged for example between different movable stages of compressor or turbine, and fixed parts (or rotating at a different speed) in the vicinity.
  • the wipers are in this case carried by spacers or rings and the lining is fixed on the stator (or on the mobile part rotating at the lowest speed preferably).
  • these seals are arranged between various turbomachine enclosures and are found in particular at the ends of the external enclosure of the combustion chamber housing, d on the one hand, on the side of the compressor outlet and, on the other hand, on the side of the turbine inlet.
  • the proper sealing function of the seal is more complex.
  • pressure balancing between various enclosures of the turbomachine is usually sought.
  • Controlled air circulation is also sought in the enclosures in order to create certain ventilation air streams which may be used in other areas of the turbomachine and thus it may be desirable to control the air flows with the best precision.
  • FR-A-2437544 in the name of the Applicant describes a seal in which the support of the wear lining is surrounded by an annular channel connected, at its downstream end, to an air intake provided in the wall of the combustion chamber casing while its other end opens upstream of the seal into the lower pressure air space surrounding the compressor shaft.
  • the adjustment of the circulation flow rate of the cooling air of the seal calls for an adjustable discharge valve controlled by an operating parameter of the turbomachine.
  • FR-A-2025869 seeks to minimize the difference in thermal expansion in a labyrinth seal by equalizing the temperatures between a casing carrying the seal and a ring carrying the wipers and connected to the rotor.
  • the external surface of the casing is isolated from the stream of hot gases by a screen providing a space in which the cooling air circulates.
  • this solution does not provide for any specific adaptation as a function of variations in the operating conditions of the turbomachine, in particular during the transient phases.
  • the invention aims to solve these problems by avoiding the drawbacks of known prior solutions.
  • a rise to full throttle speed by rapid acceleration ensuring minimum clearance between the top of the wipers and the cooperating surface of the wear lining and sealing of the labyrinth seal and also, in the event of a sudden deceleration, to avoid any penetration of the wipers into the wear layer, which would cause, in addition to various mechanical disadvantages (vibratory phenomena, overheating inducing phenomena with divergent effect), the subsequent appearance excessive play clearly detrimental to returns.
  • a minimum of play must even be kept in order to allow that a phase of re-acceleration can follow quickly.
  • the device according to the invention of the aforementioned kind is characterized in that the upstream part of the annular support carrying the wear and sealing lining comprises a series of holes peripherally distributed connecting said annular chamber and the upstream part of said cross section of the seal, so as to be supplied by a sample taken in the cooling air which passes through the labyrinth seal.
  • cooperating parts of the support carrying the wear and sealing lining and of the rotor part carrying the wipers are shaped so as to create upstream of the zone comprising said wipers and said lining an annular convergent-diverging nozzle forming a primary neck.
  • FIG. 1 there is shown schematically, in axial section, under stabilized operating conditions, a part of a turbomachine comprising an embodiment of the invention.
  • a labyrinth seal according to the invention is disposed between a fixed part and a rotating part of the turbomachine.
  • the rotating part is represented diagrammatically by a rotor part 1.
  • the fixed part comprises a stator element 2 connected in a known manner to a part 3 of the fixed structure of the turbomachine.
  • this stator element 2 is formed an annular chamber 5 closed on the interior side by an annular support 6 on the internal face of which is fixed in its downstream part a seal 7 for wear and sealing.
  • This lining is of any known and commonly used type, but preferably in the device according to the invention, the lining 7 consists of a honeycomb or of a type such that the flow rate passing through the labyrinth is not proportional to the clearance.
  • the stator element 2 has on its external diameter one or more air inlet orifices 8 and it also has on its downstream edge one or more air outlet orifices 9. These orifices 9 are placed towards the internal diameter of the element 2 and one or more other air outlet orifices 10 can be placed towards the external diameter of the element 2, always at its downstream edge.
  • Inside the annular chamber 5 of the stator element 2 is disposed a thin sheet 11 pierced with series of multi-holes 12.
  • This sheet 11 divides the annular chamber 5 into two enclosures, one external 5a comprising the air inlets 8 and the other internal 5b comprising the air outlets 9 and possibly 10.
  • the shaft 1 carries wipers 13 (5 wipers in the example shown).
  • the upstream part of the annular support 6 carrying the seal and the rotor part 1 upstream of the part carrying the wipers 13 have cooperating parts 14 on the support 6 and 15 on the rotor part 1.
  • These parts 14 and 15 are respectively shaped so as to create in the upstream space located between the support 6 and the rotor part 1 a nozzle 16 comprising a converging upstream part 17 and a diverging downstream part 18 connected by a neck 19.
  • the upstream part 14 of the support 6 comprises, in line with the neck 19, one or more bores 20 opening out on one side at the neck 19 of the convergent-diverging nozzle 16 and on the other in the external enclosure 5a of the annular chamber 5 of the element of stator 2.
  • the device according to the invention which has just been described makes it possible to obtain an improved operation by ensuring in all the operating conditions of the turbomachine both in stabilized and transient conditions a practically constant clearance guaranteeing a controlled value of the air flow rate passing through the labyrinth seal of the turbomachine on which said device is adapted without inadvertent variations being observed, the consequences of which are harmful for the yields or for the life of certain parts in the leakage rates at the level of the labyrinth seal.
  • the clearance j1 may have a tendency to decrease, as can the section j2 at the neck 19.
  • D1 denotes the air flow at the inlet of the space separating the rotor part 1 and the stator element 2, this air being at a temperature much lower than that of the gases in the vein at the height of the device
  • D2 the air flow entering the annular chamber 5 through the orifices 8 of the stator element 2
  • the point of sampling of this air in the turbomachine being chosen so that this air is hotter than that D1 supplying the joint
  • D3 the air flow taken from D1 at the neck 19 of the nozzle 16 through the orifices 20 of entry into the annular chamber 5
  • D4 the flow of cooling air passing through the joint to labyrinth
  • the clearance j1 may tend to increase and the same is true for the clearance j2.
  • the section at the neck 19 increases and that consequently the local speed decreases and the static pressure increases, this results in an increase in the flow D3 while the flow D2 decreases.
  • the air impacting on the support 6 cools and this support 6 carrying the seal 7 contracts almost immediately.
  • the effects tending to increase the play j1 are compensated for and canceled and the play j1 is again maintained at its objective value and it will be the same in all the operating conditions of the turbomachine tending to increase the play j1.
  • Fig. 2 shows an embodiment for an application of the invention to a labyrinth seal placed in line with the outlet of a combustion chamber on the radially internal side.
  • a fixing means 25 for example of the bolt-on type, to a radial flange 26 of an internal part of stator vane 27.
  • the casing 23 carries a directed radial flange 28 towards the axis of the machine and to which are fixed by fixing means, for example 29, of the bolt type, on the one hand, a radial end flange 30 of an annular support 31 which bears on its face internally a wear and sealing lining 32 and, on the other hand, a radial end flange 33 of an annular thin sheet metal 34 multi-perforated slightly spaced radially outward relative to the support 31 on which it is radial support at 35 at its downstream end.
  • the support 31 carries a radial flange 36 directed radially outwards, making the connection with the internal part of the stator blade 27.
  • the rotary rotor part comprises a disc 37 carrying in the example shown three wipers 38 cooperating with the wear and sealing lining 32.
  • the internal enclosure is separated by the disc 37 into an upstream enclosure 39 where the air is at pressure P1 and a downstream enclosure 40 at a lower pressure P2.
  • the space formed between the annular support 31 and the chamber envelope 23 constitutes an annular chamber 41 allowing the ventilation of the support 31 and separated into two enclosures 41a a and 41b by the annular sheet 34.
  • a passage of air through an opening 42a made in the envelope 23 is provided between the enclosure 24 and the chamber 41.
  • the upstream part of the wear and sealing lining 32, of the support 31 and of the thin sheet 34 have cooperating holes 42, 43 and 44 respectively for the passage of air towards the enclosure 41 a of the chamber 41.
  • the thin sheet 34 also comprises multi-perforations 45 for the ventilation by impacts of the support 31.
  • Side downstream, the support 31 and the wear and sealing lining 32 also have cooperating holes 46 and 47 respectively for the evacuation of the air from the chamber 41.
  • the wiping disc 37 has on its outside diameter upstream side a finger-shaped part 48 whose end 49 as well as the cooperating surface 50 of the upstream part of the wear and sealing lining 32 are respectively shaped so as to create a nozzle of annular convergent-diverging shape by creating a neck 51 at the level of which the catches are open. air towards the chamber 41 through the holes 42.
  • the disc 37 also carries a finger 52, the end 53 of which cooperates with the surface facing the downstream part of the wear and sealing lining 32 , through which the drainage holes 47 open.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
EP85401863A 1984-09-27 1985-09-25 Dispositif de contrôle automatique du jeu d'un joint à labyrinthe de turbomachine Expired EP0177408B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8414818A FR2570763B1 (fr) 1984-09-27 1984-09-27 Dispositif de controle automatique du jeu d'un joint a labyrinthe de turbomachine
FR8414818 1984-09-27

Publications (2)

Publication Number Publication Date
EP0177408A1 EP0177408A1 (fr) 1986-04-09
EP0177408B1 true EP0177408B1 (fr) 1988-08-24

Family

ID=9308117

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85401863A Expired EP0177408B1 (fr) 1984-09-27 1985-09-25 Dispositif de contrôle automatique du jeu d'un joint à labyrinthe de turbomachine

Country Status (5)

Country Link
US (1) US4668163A (enrdf_load_stackoverflow)
EP (1) EP0177408B1 (enrdf_load_stackoverflow)
JP (1) JPS6183403A (enrdf_load_stackoverflow)
DE (1) DE3564600D1 (enrdf_load_stackoverflow)
FR (1) FR2570763B1 (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4110616A1 (de) * 1990-04-03 1991-10-10 Gen Electric Thermisch abgestimmte drehlabyrinthdichtung mit aktiver dichtspaltsteuerung

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4961310A (en) * 1989-07-03 1990-10-09 General Electric Company Single shaft combined cycle turbine
US5090865A (en) * 1990-10-22 1992-02-25 General Electric Company Windage shield
US5259725A (en) * 1992-10-19 1993-11-09 General Electric Company Gas turbine engine and method of assembling same
DE4337281A1 (de) * 1993-11-02 1995-05-04 Abb Management Ag Verdichter
DE19756734A1 (de) * 1997-12-19 1999-06-24 Bmw Rolls Royce Gmbh Passives Spalthaltungssystem einer Gasturbine
US5984630A (en) * 1997-12-24 1999-11-16 General Electric Company Reduced windage high pressure turbine forward outer seal
RU2147690C1 (ru) * 1998-02-02 2000-04-20 Открытое акционерное общество "Авиадвигатель" Уплотнительная втулка газотурбинного двигателя
US6471216B1 (en) * 1999-05-24 2002-10-29 General Electric Company Rotating seal
US6715766B2 (en) * 2001-10-30 2004-04-06 General Electric Company Steam feed hole for retractable packing segments in rotary machines
US7249463B2 (en) * 2004-09-15 2007-07-31 General Electric Company Aerodynamic fastener shield for turbomachine
US7094020B2 (en) * 2004-09-15 2006-08-22 General Electric Company Swirl-enhanced aerodynamic fastener shield for turbomachine
FR2881472B1 (fr) * 2005-01-28 2011-07-15 Snecma Moteurs Circuit de ventilation d'un rotor de turbine haute pression dans un moteur a turbine a gaz
US8074998B2 (en) * 2006-05-05 2011-12-13 The Texas A&M University System Annular seals for non-contact sealing of fluids in turbomachinery
JP2009236038A (ja) * 2008-03-27 2009-10-15 Toshiba Corp 蒸気タービン
RU2493389C2 (ru) * 2008-11-28 2013-09-20 Прэтт энд Уитни Кэнэдэ Корп. Подвижный уплотнительный элемент и способ управления радиальным зазором между подвижным уплотнительным элементом и углеродным уплотнением газотурбинного двигателя
US8668431B2 (en) * 2010-03-29 2014-03-11 United Technologies Corporation Seal clearance control on non-cowled gas turbine engines
GB201012719D0 (en) * 2010-07-29 2010-09-15 Rolls Royce Plc Labyrinth seal
US9255642B2 (en) * 2012-07-06 2016-02-09 General Electric Company Aerodynamic seals for rotary machine
US9238971B2 (en) * 2012-10-18 2016-01-19 General Electric Company Gas turbine casing thermal control device
FR3007064B1 (fr) * 2013-06-13 2018-06-29 Composite Industrie Secteur de joint annulaire abradable pour turbomachine et procede de fabrication d'une telle piece
FR3007063B1 (fr) 2013-06-13 2015-07-03 Composite Ind Piece de materiau abradable pour la fabrication d'un secteur de joint annulaire abradable pour turbomachine et procede de fabrication d'une telle piece
DE102015215144B4 (de) 2015-08-07 2017-11-09 MTU Aero Engines AG Vorrichtung und Verfahren zum Beeinflussen der Temperaturen in Innenringsegmenten einer Gasturbine
US10815816B2 (en) 2018-09-24 2020-10-27 General Electric Company Containment case active clearance control structure
US11821365B2 (en) * 2022-01-31 2023-11-21 General Electric Company Inducer seal with integrated inducer slots
CN116537895B (zh) * 2023-07-04 2023-09-15 中国航发四川燃气涡轮研究院 一种带有篦齿间隙控制的预旋供气系统

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3018085A (en) * 1957-03-25 1962-01-23 Gen Motors Corp Floating labyrinth seal
US3527053A (en) * 1968-12-11 1970-09-08 Gen Electric Gas turbine engine with improved gas seal
FR2280791A1 (fr) * 1974-07-31 1976-02-27 Snecma Perfectionnements au reglage du jeu entre les aubes et le stator d'une turbine
US3989410A (en) * 1974-11-27 1976-11-02 General Electric Company Labyrinth seal system
US4103899A (en) * 1975-10-01 1978-08-01 United Technologies Corporation Rotary seal with pressurized air directed at fluid approaching the seal
US4060250A (en) * 1976-11-04 1977-11-29 De Laval Turbine Inc. Rotor seal element with heat resistant alloy coating
US4177004A (en) * 1977-10-31 1979-12-04 General Electric Company Combined turbine shroud and vane support structure
FR2437544A1 (fr) * 1978-09-27 1980-04-25 Snecma Perfectionnements aux joints a labyrinthe
US4554789A (en) * 1979-02-26 1985-11-26 General Electric Company Seal cooling apparatus
FR2452601A1 (fr) * 1979-03-30 1980-10-24 Snecma Support amovible de revetement d'etancheite pour carter de soufflante de turboreacteur
US4526226A (en) * 1981-08-31 1985-07-02 General Electric Company Multiple-impingement cooled structure
US4573865A (en) * 1981-08-31 1986-03-04 General Electric Company Multiple-impingement cooled structure
FR2540560B1 (fr) * 1983-02-03 1987-06-12 Snecma Dispositif d'etancheite d'aubages mobiles de turbomachine
US4466239A (en) * 1983-02-22 1984-08-21 General Electric Company Gas turbine engine with improved air cooling circuit
US4513975A (en) * 1984-04-27 1985-04-30 General Electric Company Thermally responsive labyrinth seal

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4110616A1 (de) * 1990-04-03 1991-10-10 Gen Electric Thermisch abgestimmte drehlabyrinthdichtung mit aktiver dichtspaltsteuerung

Also Published As

Publication number Publication date
FR2570763B1 (fr) 1986-11-28
US4668163A (en) 1987-05-26
FR2570763A1 (fr) 1986-03-28
DE3564600D1 (en) 1988-09-29
JPS6183403A (ja) 1986-04-28
EP0177408A1 (fr) 1986-04-09
JPH0379524B2 (enrdf_load_stackoverflow) 1991-12-19

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