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
  • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
  • F01D25/08—Cooling; Heating; Heat-insulation
  • F01D25/12—Cooling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2220/00—Application
  • F05D2220/30—Application in turbines
  • F05D2220/32—Application in turbines in gas turbines
  • F05D2220/321—Application in turbines in gas turbines for a special turbine stage
  • F05D2220/3215—Application in turbines in gas turbines for a special turbine stage the last stage of the turbine
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2240/00—Components
  • F05D2240/90—Mounting on supporting structures or systems
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
  • F05D2260/00—Function
  • F05D2260/20—Heat transfer, e.g. cooling
  • F05D2260/201—Heat transfer, e.g. cooling by impingement of a fluid

Definitions

• the invention lies in the field of cooling a turbine casing, in particular a low pressure turbine, a turbomachine.
• the present invention more specifically relates to a device for fixing air jet cooling ramps of the casing of a turbine of a turbomachine.
• the invention also relates to a turbomachine equipped with such a device.
• FIG. 1 and 2 attached which represent the state of the art, the low-pressure turbine of a turbomachine is protected by a housing C generally flared, substantially frustoconical. This housing is cooled using impact cooling technology.
• the casing C is equipped with one or more box (es) B of pressurized air supply, connected to several cooling ramps R.
• the housing C is equipped with two housings B, positioned at about 180 ° from each other (only one being visible in Figure 2).
• Each box B is equipped with five ramps R, with two tubes T by ramps, each tube extending about 90 °.
• the tubes T are pierced with a series of small openings opening to the right of the outer surface of the housing. The pressurized air passing through these orifices ensures impact ventilation of the casing C.
• FIG. 1 it can be seen that the supports S of the cooling ramps R are fixed to the casing by an upstream flange BAM and by a downstream flange BAV. Although not shown, the boxes B are fixed on the housing in the same way. In cold, that is to say when the turbines are stopped, the air gap E between an air outlet orifice formed in a tube T and the outer surface of the casing C (or "housing skin" PC) is of the order of 5 to 6 mm.
• the metal casing C tends to expand radially but especially longitudinally.
• the upstream flanges BAM and downstream BAV remain colder and do not expand in the same way as the skin of the PC casing. It follows that cooling ramps R tend to approach or even touch the skin of the PC housing in places.
• the air gap E cold is important, it is insufficient hot.
• the ramp must be located very close to the skin of the PC housing and therefore keep a constant air gap E.
• the positioning of the hot ramp is not correct, and the ramp may be either too far or too close (or even in contact) with the housing skin during operation of the turbines. It is therefore necessary to find a fixing means to maintain a constant air gap regardless of the temperature.
• the invention therefore aims to solve the aforementioned drawbacks of the state of the art.
• the invention particularly aims to provide a device for fixing air jet cooling ramps of the casing of a turbomachine turbine, which avoids the air gap variations between said ramps and the outer wall of the housing, and this, even hot, that is to say during the use of the turbine.
• the invention relates to a device for fixing air jet cooling ramps of the casing of a turbine, preferably a low-pressure turbine, a turbomachine comprising a support for said ramps, shaped to maintain said ramps spaced between they and several support elements of said ramp support, each support element being fixed to said housing and connected to said ramp support by connecting means.
• the device comprises N cooling ramps and N-1 support elements, each support element being disposed between two contiguous cooling ramps.
• the gap between the ramps and the outer wall of the housing remains constant, even during hot use.
• the integral support elements of the ramp support are disposed between two adjacent cooling ramps, and retain them at a constant distance from the skin of the housing.
• these support elements being attached to the housing, they are subject to the same temperature changes as the housing and expand according to the deformations thereof.
• said support of the ramps comprises two blades called “inner blade” and outer blade, each of which comprises a series of parallel grooves, separated by a flat zone, each groove being shaped to surround part of the circumference of one of said ramps, preferably half, the inner blade and the outer blade being assembled on both sides of the cooling ramps, so that their respective grooves are opposite one another and surround said ramps;
• connecting means are so-called “fixed” means, which do not allow relative movement between said ramp support and a support element;
• the connecting means are so-called “mobile” means, which allow relative movement between said ramp support and a support element; the support element is pierced with a circular orifice, the flat zones of the blades of the ramp support are pierced with a circular orifice and the support element and the two blades are assembled by a screw passing through the two circular orifices. and cooperating with a nut, the circular orifices, the screw and the nut constituting said fixed connection means;
• the support element is pierced with a circular orifice, the flat zones of the blades of the ramp support are pierced with an oblong orifice and the support element and the two blades are assembled by a stepped pin passing through the orifice; circular and the two orifices oblong and cooperating with a washer, the assembly being made to allow axial sliding of said blades relative to the stepped pin at the oblong holes so as to achieve a movable connection;
• the support element is a bridge, fixed at both ends to the housing and whose projecting central portion is connected to said ramp support.
• the invention also relates to a turbomachine which comprises a device for fixing said cooling ramps as mentioned above.
• FIG. 1 is a perspective view of a portion of a casing of a turbine of a turbomachine, equipped with cooling ramps according to the state of the art
• FIG. 2 is a perspective view of an air supply box and cooling ramps according to the state of the art
• FIGS. 3 to 6 are perspective views showing two embodiments of the various elements constituting the device for fixing the cooling ramps according to the invention.
• FIG. 7 is a cross-sectional view of the device according to the invention representing two embodiments
• FIGS. 8 and 9 are detailed views of the zones referenced
• cooling ramps 1 on the casing 2 of a turbine, preferably a low pressure turbine, a turbomachine.
• the cooling ramps 1 and the casing 2 have the same shapes and structures as those previously described in connection with FIGS. 1 and 2 for the state of the art.
• the cooling ramps 1 are formed of tubes of cross section, preferably circular and have a curved shape in a circular arc, matching the outer shape of the housing 2.
• the latter has a flared shape and comprises a surface 21, an upstream end 22 and a downstream end 23.
• the fixing device bears the general reference 3. It comprises a support 4 of said ramps 1 and several elements 5 for supporting said support 4.
• This support 4 comprises two blades, respectively called inner blade 41 and outer blade 42.
• the inner blade 41 is intended to be arranged close to the outer surface 21 of the housing, it comprises a series of parallel grooves 41 1, perpendicular to the blade and separated from each other by a intermediate flat area 412.
• Each groove 41 1 is shaped to surround at least a portion of the circumference of one of said ramps 1.
• the inner radius of the groove 41 1 substantially corresponds to the outer radius of a cooling ramp 1.
• each groove surrounds half the circumference of a ramp.
• the outer blade 42 intended to be disposed outside the ramps 1, also has a series of parallel grooves 421 spaced apart from each other by a flat zone 422 (see FIG. 1).
• the inner blade 41 and the inner blade 42 are assembled on either side of the cooling ramps 1, so that their respective grooves 41 1, 412 are opposite one another and surround said ramps, as one can be seen in Figures 6 and 7.
• the support 4 of ramps thus makes it possible to keep the ramps 1 spaced apart from each other, in the axial direction of the casing 2.
• the support element 5 has the shape of a bridge as can be seen in Figure 3.
• Each bridge comprises two ends 51 and a projecting central portion 52.
• the ends 51 are fixed to the casing 2, more precisely on the outer surface 21 thereof (also known as the "skin of the casing"), more precisely still on the portion of the outer surface 21 that extends between the upstream ends 22 and downstream 23.
• This fixing is carried out by any appropriate means, for example by welding, brazing, bonding, riveting or bolting.
• Each support element 5 is connected to the support 4, that is to say to the two blades 41 and 42 by so-called “fixed” 6 or “mobile” connecting means 6 '.
• the central portion 52 of the bridge is pierced with a circular orifice
• the assembly of the various elements constituting the fixing device 3 is carried out as follows.
• the various support elements 5 are fixed on the casing 2.
• the inner blade 41 is then fixed on these support elements 5, so that its planar zones 412 are positioned opposite the flat central part. protruding 52 of the bridge 5 (see Figure 4).
• the outer blade 42 is positioned on the ramps 1, so that the grooves 421 enclose the ramps 1 and that the flat areas 422 are positioned opposite the planar zones 412 of the inner blade 41.
• the support elements 5 in accordance with the invention are N-1 in number and are arranged between the two cooling ramps 1 of each pair of ramps.
• At least one additional support element 5 may be further provided at at least one of the two ends of the ramp support 4.
• the connecting means 6 are said to be “fixed” in that they do not allow any relative movement between the ramp support 4 and a support element 5. This solution is represented in FIG. 8 and in the lower left corner of FIGS. Figures 4 to 7.
• the two blades 41 and 42 and the bridge 5 are assembled by means of a screw 7 passing through said orifices 53, 413 and 423 and a nut 8 screwed onto the screw.
• the screw 7 being circular and the orifices 413 and 423 also and of the same diameter, there is no possibility of relative movement of the blades of the support 4 relative to the elements 5 of this support.
• the connecting means 6 ' are said to be “mobile” in that they allow relative movement between the ramp support blades 41, 42 and a support element 5.
• the holes formed in the blades 41 and 42 are oblong and are respectively referenced 413 'and 423'.
• the assembly is carried out with a stepped pin 7 'and a washer 8'.
• the blades 41 and 42 can slide axially relative to the stepped pin 7 ', so that the blades 41 and 42 can follow the expansion movement of the housing 2, including its axial expansion movement.
• the fixed connection means 6 are used near the upstream end of the casing and the mobile connection means 6 'in the center and near the downstream end of the casing.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Turbine Rotor Nozzle Sealing (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=55022541

Family Applications (1)

Country Status (5)

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• 2015
  • 2015-08-27 FR FR1557978A patent/FR3040429B1/fr active Active
• 2016
  • 2016-08-25 EP EP16770056.6A patent/EP3341570B1/de active Active
  • 2016-08-25 US US15/755,525 patent/US10619511B2/en active Active
  • 2016-08-25 CN CN201680049155.1A patent/CN107923259B/zh active Active
  • 2016-08-25 WO PCT/FR2016/052120 patent/WO2017032952A1/fr active Application Filing

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