Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
  • F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
  • F23R3/28—Continuous combustion chambers using liquid or gaseous fuel characterised by the fuel supply
  • F23R3/283—Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances

Definitions

• the present invention relates to the field of gas turbine engines and in particular that of the combustion chambers of such engines.
• the combustion chamber of a gas turbine engine receives compressed air from the upstream high pressure compressor and provides a combustion-heated gas in a fuel-fired combustion zone.
• the chamber thus comprises an upstream chamber bottom wall on which the different fuel injection systems are fixed.
• Figure 1 shows a chamber of the prior art.
• the annular chamber 1 is housed inside a housing 2 of the engine downstream of the diffuser 3 of compressed air. It comprises an inner wall 4 and an outer wall 5 delimiting between them a combustion zone.
• the chamber In its upstream part the chamber comprises a transverse wall 6 of bottom chamber on which are provided openings each equipped with a system 7 for supplying carbureted air.
• Such a system is supplied with fuel from a liquid fuel injector and includes concentric annular grids to create swirling air streams promoting their mixing with the sprayed fuel web.
• Part of the air from the diffuser is diverted from the fuel intake zone through the shroud 8 and flows along and out of the outer wall as well as along and out of the inner wall.
• the primary combustion zone is therefore immediately downstream of the wall of the chamber bottom.
• Deflectors 9 made of metallic material line the inside of the wall of the chamber bottom and serve to protect it from the intense radiation produced in the primary combustion zone.
• Air is introduced through orifices made in the wall of the chamber bottom behind the baffles to ensure their cooling. This air flows along the rear face of the baffles and is then guided to form a film along the longitudinal outer walls of the chamber.
• baffle CMC ceramic matrix composite
• CMCs ceramic matrix components
• They are formed of a carbon fiber reinforcement or refractory material and a ceramic matrix.
• the manufacture of a CMC comprises the production of a fiber preform intended to constitute the reinforcement of the structure, and the densification of the preform by the ceramic material of the matrix.
• CMCs have the advantage of maintaining their mechanical properties up to high temperatures in an oxidizing medium.
• a CMC has a thermal expansion rate four times lower than the metal used for the chamber.
• this material can not be welded or soldered.
• the applicant has set a goal to develop a manner of mounting deflectors of CMC type material on the bottom wall of a combustion chamber. According to the invention, this object is achieved with a combustion chamber having the features reported in the main claim.
• the sheath is preferably fixed by brazing to the wall and the mechanical attachment means is interconnection.
• the cup is mounted with clearance inside the cylindrical part of the baffle when the chamber is cold, the play being reduced if not eliminated at the operating temperatures of the combustion chamber.
• This game allows the assembly of parts and takes into account their difference in expansion.
• the cup comprises a radial flange through which it is fixed by welding to the metal sleeve.
• the carbureted air supply system comprises a bowl fixed by a flange to the metal sheath.
• the mechanical attachment means of the baffle cooperates with a deflector support attached to the sleeve.
• This support forms an intermediate piece which makes it possible to move the brazing zones away from the metal parts without damaging the CMC material constituting the deflector.
• the cylindrical portion of the deflector is integral with a cylindrical element forming a cup, housed, with cold play, inside the annular flange of the deflector, said cup member ensuring the guiding of the deflector when the temperature has increased.
• FIG. 1 shows in axial half-section a combustion chamber of a gas turbine engine of the prior art
• FIG. 2 partially shows the chamber bottom according to the invention in axial section, with a magnifying glass which shows in more detail the mounting area of the deflector in the chamber bottom
• FIGS. 3 to 6 show the succession of the stages of assembly of the deflector in the chamber bottom;
• FIG. 7 shows in axial section an alternative embodiment of the invention.
• FIG. 2 there is shown a chamber bottom according to one embodiment of the invention.
• the bottom wall 11 of the chamber 10 is protected from the radiation of the combustion zone by a deflector 12 made of CMC material.
• the shape of the deflector is substantially the same as that of the deflector 9 of the prior art with a generally flat portion 12A which is placed parallel to the wall 11 and two portions 12b curved towards the outer and inner walls.
• the deflector 12 is open in its central part with a cylindrical portion 12c having the same axis as the fuel air supply system 13.
• a metal sleeve 14 In the opening of the wall 11 of the chamber bottom, is fixed a metal sleeve 14.
• a solder 14a holds the sleeve 14 against the inner edge of the opening of the wall 11.
• the sleeve comprises a cylindrical portion 14b and a portion radial 14c, the latter providing a space with a stopper 15 which is welded to its periphery.
• 14d transverse teeth facing the axis of the opening of the wall 11 are formed inside the cylindrical portion 14b of the sleeve 14.
• a centering cup 16 comprises a cylindrical portion 16a and a flange 16b radial and transverse. The cup 16 is disposed inside the cylindrical portion 14b of the sleeve and fixed by a weld bead 16c peripheral to the sleeve 14.
• the cylindrical portion 16a of the cup is inside the cylindrical portion 12c.
• the deflector 12 comprises a transverse groove 12c1 on the outer face of the cylindrical portion 12c, forming a housing 14d teeth of the sheath.
• the groove is perforated to allow the axial passage of the teeth 14d to the assembly and the locking by rotation of the sleeve relative to the cylindrical portion 12c of the deflector 12.
• This mechanical fastening mode from the baffle to the sheath is of the type interconnection. Other modes of mechanical fixing are possible.
• the cylindrical portion 16a of the cup is inside the cylindrical portion 12c, with the mounting a radial clearance.
• the device for injecting and carburizing air is represented generally by the reference 13. It is not detailed to the extent that the subject of the invention does not concern it.
• the diverging bowl 13a of the device comprises externally a transverse flange 13b housed in the space formed between the radial face 14c of the sleeve 14 and the stopper 15.
• Figure 3 shows the sleeve 14 against the wall 11 of the chamber bottom externally to the chamber. It is centered on the inner edge of the corresponding opening of the wall 11.
• the deflector 12 is put into place, in FIG. 4, in the sleeve 14 from the inside of the chamber.
• the teeth 14d are inserted axially through the openings in the groove 12c1.
• the sleeve 14 is rotated so as to lock the teeth axially relative to the annular flange 12c.
• the sleeve 14 is then clutched in the deflector 12 by the cooperation of the teeth 14d and the groove 12cl.
• the sheath 14, FIG. 5, is fixed by brazing it on the chamber bottom with the solder bead 14a, FIG. 2 and an anti-rotation pin 18 is placed between the diameter of the sheath and that of the deflector.
• the centering cup 16 is slid into the cylindrical portion 12c of the deflector. And the cup is fixed by a point or a weld bead 16c between the latter and the sleeve 14.
• the fuel injection device 13 is mounted that is immobilized by the stop plate 15. It is welded to the sheath.
• This mounting mode of the deflector makes it possible to immobilize it in the wall of the chamber bottom by a mechanical means of attachment.
• the welds are made only between the metal parts. Differential expansion of the deflectors with respect to the metallic environment is taken into account by means of the centering cup which, by expanding radially, immobilizes the deflector in position.
• the clearance between the sleeve and the baffle on the one hand and the baffle and the centering cup on the other hand are to be optimized according to the operating temperatures and the diameter of the parts.
• the assembly principle is generally the same as before; we simply modified the sheath and the cup.
• a baffle support sleeve 26, annular comprises transverse teeth 26d cooperating with the outer groove 12c1 of the annular flange of the deflector.
• the support sleeve 26 is slid axially from the outside of the chamber with insertion of the teeth 26d into the groove 12c1 by the openings (not visible) of the groove.
• a rotation around the axis of the opening allows the interconnection of the support sleeve 26 with the deflector.
• the support sleeve 26 has a cylindrical portion 26a, forming a cylindrical centering cup radially inner which fits inside the flange 12c. In cold mounting, a clearance is provided between the cylindrical portion 26a of the support sleeve and the flange 12c of the deflector. The centering is ensured by the mechanical attachment to clutch.
• the deflector support sleeve expands more than the deflector CMC material.
• the cylindrical portion bears against the inner face of the clamp 12c with clamping and ensures the centering of the deflector.
• the fuel injection device 13 is mounted as before by the outside of the chamber, a transverse flange 13b being immobilized between the rear face of the deflector support 26 and a stop cup 15 brazed to the support.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Combustion Methods Of Internal-Combustion Engines (AREA)
• Fuel-Injection Apparatus (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (2)

Family

ID=40289257

Family Applications (1)

Country Status (9)

Cited By (2)

Families Citing this family (21)

Family Cites Families (28)

• 2008
  • 2008-06-10 FR FR0803226A patent/FR2932251B1/fr active Active
• 2009
  • 2009-06-10 US US12/997,266 patent/US8756935B2/en active Active
  • 2009-06-10 BR BRPI0914905A patent/BRPI0914905B1/pt active IP Right Grant
  • 2009-06-10 CA CA2727254A patent/CA2727254C/fr active Active
  • 2009-06-10 CN CN2009801216000A patent/CN102057224B/zh active Active
  • 2009-06-10 JP JP2011512971A patent/JP5475757B2/ja active Active
  • 2009-06-10 EP EP09772283.9A patent/EP2307805B1/fr active Active
  • 2009-06-10 RU RU2010154030/06A patent/RU2507452C2/ru active
  • 2009-06-10 WO PCT/EP2009/057147 patent/WO2010000583A2/fr not_active Ceased

Also Published As

Similar Documents

Legal Events