TRIPLE-FLOW TURBOMACHINE WITH A HEAT EXCHANGER IN THE THIRD FLOW MOUNTED ON AN INTER-VEIN COMPARTMENT

Abstract

TRIPLE-FLOW TURBOMACHINE WITH A HEAT EXCHANGER IN THE THIRD FLOW MOUNTED ON AN INTER-FLOW COMPARTMENT The invention relates to a turbomachine (2), comprising: a separation nozzle adapted to separate a radially internal airflow into a primary flow and a tertiary flow, the latter running through a tertiary flow vein (16) radially external to a primary flow vein through which the primary flow flows; a heat exchanger (18) disposed in the tertiary flow vein; and an internal casing; the turbomachine being notable in that at least one heat exchanger comprises a body (32) mounted on the internal casing (28) by means of at least one intermediate piece (40) comprising a wall (42) disposed against the internal casing and a flange (44) to an upstream edge (41) of said wall, the body engaging with said flange. (Figure to be published with the abbreviation: Figure 2)

Description

Title of the invention: TRIPLE-FLOW TURBOMACHINE WITH A HEAT EXCHANGER IN THE THIRD FLOW MOUNTED ON AN INTER-VEIN COMPARTMENT Technical field

[0001] The invention relates to the field of turbomachines and more particularly to multi-flow turbomachines. The invention relates to the arrangement of a heat exchanger intended for cooling the oil of the turbomachine. Prior art

[0002] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft and those in circulation requiring the implementation of technological solutions in order to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change.

[0003] Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft. The Applicant takes into consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental consequences with the aim of improving the energy efficiency of aircraft.

[0004] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0005] This sustained research and development work covers new generations of aircraft engines, the lightening of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to ensure propulsion, and, as essential complements to technological progress, aeronautical biofuels.

[0006] In this context, the invention relates more particularly to the aspects related to the arrangement of heat exchangers in turbomachines. Indeed, in a In a turbomachine, it is generally necessary to cool the oil in the lubrication circuit. It is known to have one or more heat exchangers in the tertiary flow of a three-flow turbomachine, i.e. in the radially intermediate flow between the primary flow directed towards the combustion chamber and the secondary or external flow.

[0007] The integration of an exchanger in the third flow, confined between the primary flow and the secondary or external flow, poses difficulties of assembly and accessibility in the event of maintenance, but also constraints linked to sealing in operation due to the thermal expansion of the exchanger. An exchanger of the “brick” type inspired by document FR 3 089 248 A1 does not meet these constraints and is therefore not suitable for the third flow.

[0008] The integration of an exchanger into a third flow of a three-flow turbomachine therefore presents challenges linked to its size, its assembly, its accessibility, its operation and also to the overall mass of the means used to fix it to the casing. Statement of the invention

[0009] The present invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a simple, efficient and economical solution aimed at solving the drawbacks of the design / manufacture of turbomachines of the state of the art. In particular, the invention aims to propose a solution which allows efficient cooling in a restricted space requirement while guaranteeing accessibility of the exchanger during a maintenance operation, and guaranteeing sealing, but also without adding mass and without hindering the efficiency of the turbomachine.

[0010] For this purpose, the present invention relates to an axial turbomachine, comprising: - a first separation nozzle capable of separating an incoming air flow into a radially internal air flow and a radially external air flow, called a secondary flow; - a second separation nozzle capable of separating the radially internal air flow into a primary flow and a tertiary flow, the latter traveling through a tertiary flow vein radially external to a primary flow vein traveled by the primary flow; - a heat exchanger placed in the tertiary flow vein; and - an internal casing radially internally delimiting the tertiary flow stream; the turbomachine being remarkable in that the at least one heat exchanger comprises a body mounted on the internal casing by means of at least one intermediate part comprising a wall arranged against the internal casing and a flange at an upstream edge of said wall, the body engaging with said flange.

[0011] Advantageously, the engagement of the body with the flange is devoid of any fixing, which makes it possible to avoid the creation of zones of mechanical stress when the exchanger undergoes thermal expansion. To this end, the assembly of the body of the at least one exchanger with the at least one intermediate part allows expansion deformations in the axial, radial and circumferential directions.

[0012] The internal casing preferably corresponds to an inter-blade cowling of the turbomachine which is arranged between the primary flow vein and the tertiary flow vein.

[0013] According to an advantageous embodiment of the invention, the at least one intermediate part has a transverse profile in the form of an arc of a circle corresponding to the tertiary flow vein. The term “corresponding” can be translated here as: “coaxial to”.

[0014] According to an advantageous embodiment of the invention, the flange has a longitudinal section with a radial portion connecting to the wall and a longitudinal portion parallel to the wall.

[0015] Advantageously, the internal casing and the longitudinal portion of the flange are in aerodynamic continuity with the tertiary flow vein, and preferably constitute a radially internal guide wall for the tertiary flow.

[0016] According to an advantageous embodiment of the invention, the radial portion of the flange is fixed to the internal casing by means of a ring arranged against an upstream face of said radial portion and fixed to the internal casing.

[0017] According to an advantageous embodiment of the invention, the radial portion of the flange comprises a rib in the shape of an arc of a circle corresponding to the tertiary flow vein and engaging with a lower edge on the ring. The term "corresponding" can be translated here as: "coaxial to".

[0018] Preferably, the arcuate rib projects upstream from the upstream face of the radial portion, said rib radially supporting the ring.

[0019] According to an advantageous embodiment of the invention, the wall comprises a downstream edge engaging by pivoting of the at least one intermediate part during assembly with at least one hook of the internal casing.

[0020] Advantageously, the downstream edge of the wall comprises at least one protuberance extending radially through at least one corresponding notch formed on the at least one hook of the casing, said at least one protuberance ensuring fixed angular positioning (along the circumferential direction) of the intermediate part with the internal casing.

[0021] According to an advantageous embodiment of the invention, the at least one intermediate part comprises on a radially inner face of the wall a layer of flexible material contacting the internal casing so as to ensure airtightness.

[0022] Preferably, the layer of flexible material corresponds to an insulating seal extending substantially over a periphery of the wall of the at least one intermediate part. This seal advantageously makes it possible to guarantee the seal between the exchanger and the internal casing, so as to avoid air leaks in an inter-vein compartment, while avoiding the addition of fixing elements of the upstream part of the exchanger to the casing which would have the purpose of stiffening the exchanger and preventing its deformation.

[0023] According to an advantageous embodiment of the invention, the turbomachine comprises structural arms extending radially in the tertiary flow stream, the at least one heat exchanger and the at least one intermediate part being arranged between at least two adjacent structural arms of said structural arms.

[0024] The structural arms delimit between them inter-arm spaces around the tertiary flow vein. Preferably, the at least one exchanger comprises a plurality of exchangers, each of said heat exchangers being indexed on a respective intermediate part in each inter-arm space, and each of the intermediate parts respectively comprising an insulating seal extending at least circumferentially in the inter-arm spaces. Advantageously, the insulating seal guarantees sealing and thermal insulation over 360° around the longitudinal axis.

[0025] According to an advantageous embodiment of the invention, the body comprises an upstream part provided with indexing pins extending projecting and upstream from the body, the at least one exchanger being indexed on the at least one intermediate part by means of said indexing pins.

[0026] Advantageously, the indexing pins allow simplified fixing of the at least one exchanger in the tertiary flow vein.

[0027] In this configuration, the at least one exchanger is advantageously mounted directly on the at least one intermediate part, such mounting is carried out from downstream to upstream, and by simple insertion, thus facilitating the accessibility of the exchanger and its maintainability.

[0028] The invention also relates to a method for dismantling an exchanger in a turbomachine according to the invention, the method comprising removing the exchanger by moving it axially downstream.

[0029] According to an advantageous embodiment of the invention, the axially downstream movement disengages indexing pins from the exchanger body from the intermediate part.

[0030] Advantageously, the disassembly of the exchanger is partly facilitated by means of the indexing pins inserted in a floating manner in corresponding housings arranged in line with the flange, and requiring only a simple manual removal downstream.

[0031] The invention also relates to a method of installing an exchanger in a turbomachine according to the invention, the method comprising the following steps: - fixing the intermediate part on the internal casing; - installation of the exchanger by moving it axially upstream.

[0032] According to an advantageous embodiment of the invention, the axially upstream movement engages indexing pins of the exchanger body with the intermediate part.

[0033] Advantageously, the exchanger, in addition to being able to effectively cool the oil by exchanging calories with the air, makes it possible to ensure the aerodynamic continuity of the tertiary flow, and this in a sealed manner while avoiding any risk of air leakage towards the inter-vein compartment. In this configuration, the number of intermediate parts which would have been introduced to separately respond to the different required functions is greatly reduced, thus making it possible to reduce the mass and the manufacturing cost of the turbomachine of the invention. To this end, the assembly and disassembly of the exchanger are facilitated, which thus makes it possible to improve the maintainability of the turbomachine.

[0034] Furthermore, the invention is particularly advantageous, because the positioning of the exchanger at the level of the tertiary flow vein makes it possible to avoid degrading the engine's efficiency. This results in energy efficiency and optimized thrust which advantageously make it possible to reduce fuel consumption and greenhouse gas emissions, thus reducing the environmental impact of aircraft.

[0035] It is understood that each detail of an embodiment below can be combined with each other detail of the other embodiments. Brief description of the drawings

[0036] [Fig-1] represents a longitudinal sectional view of a turbomachine according to the invention, said turbomachine comprising a heat exchanger in a tertiary flow vein;

[0037] [Fig.2] represents an enlarged longitudinal sectional view of [Fig.l] showing the heat exchanger mounted on the inner casing by means of an intermediate piece;

[0038] [Fig.3] represents a perspective view of the intermediate part comprising a wall and a flange at an upstream edge of said wall;

[0039] [Fig.4] represents a longitudinal sectional and perspective view of the intermediate part comprising a layer of flexible material contacting the internal casing;

[0040] [Fig.5] represents a longitudinal sectional and perspective view of the intermediate part comprising a downstream edge engaging by pivoting of said intermediate part during assembly with a hook of the internal casing;

[0041] [Fig.6] represents a perspective view of the downstream edge of the intermediate piece of [Fig.5], including a protrusion extending radially through a corresponding notch formed on the hook of the internal casing;

[0042] [Fig.7] represents a perspective view and longitudinal section of the tur- machine when mounting the intermediate part on the internal casing;

[0043] [Fig.8] represents a perspective and longitudinal sectional view of the turbomachine in which the flange of the intermediate part is fixed to the internal casing by means of a ring arranged against an upstream face of said flange and fixed to the internal casing. Detailed description

[0044] In the following description, the terms "internal" and "external" refer to a positioning relative to the longitudinal axis of rotation of a turbomachine. The axial direction corresponds to the direction along the longitudinal axis of rotation of the turbomachine. The radial direction is perpendicular to the longitudinal axis. Upstream and downstream refer to the direction of flow of a stream in the turbomachine.

[0045] The figures show the elements schematically and are not drawn to scale. In particular, certain dimensions are enlarged to facilitate reading of the figures.

[0046] [Fig.l] illustrates a turbomachine 2 comprising a propeller 4 secured to a hub 6 rotating around a longitudinal axis 8.

[0047] The turbomachine 2 moves in an air flow F whose movement relative to the turbomachine 2 is generated by the rotation of the propeller 4 and the advancement of the aircraft on which the turbomachine 2 is mounted.

[0048] The air flow F is separated by a first separation nozzle 10 into a radially internal air flow F' and a radially external air flow F2, called secondary flow F2. The propeller 4 can be arranged upstream of the first separation nozzle 10 or downstream.

[0049] The radially internal air flow F' optionally passes through a mobile wheel (not shown) which directs the latter towards a second separation nozzle 14 capable of separating the radially internal air flow F' into a primary flow F1 and a tertiary flow F3, the latter being distinct from the secondary flow F2.

[0050] The first separation nozzle 10 comprises an inner wall forming a first outer guide wall 11 for the radially inner air flow F', said first outer guide wall 11 forming a convex profile seen from said radially inner air flow F'.

[0051] The second separation nozzle 14 comprises an external wall forming a second external guide wall 13 of the radially internal air flow F', said second external guide wall 13 forming a convex profile seen from the tertiary flow F3. For this purpose, the second external guide wall 13 corresponds to a radially internal guide wall 13 of the tertiary flow F3.

[0052] The tertiary flow F3 enters a tertiary flow vein 16 radially external to said primary flow FL. The tertiary flow F3 passes through a heat exchanger 18 arranged in the tertiary flow vein 16.

[0053] The heat exchanger 18 extends radially and axially in the tertiary flow vein 16, and preferably in an upstream section 20 of the tertiary flow vein 16, having a longitudinal section diverging in the direction of flow of the tertiary flow F3.

[0054] The heat exchanger 18 is arranged axially approximately between the high pressure compressor 15 and the low pressure compressor 17, called “booster” 17, in line with an inter-compressor casing.

[0055] The high pressure 15 and low pressure 17 compressors comprise rotating blades and rectifier blades arranged in a primary flow vein 21 crossed by the primary flow F1, the latter heading towards a combustion chamber 23.

[0056] A “VBV” channel 19 (Variable Bleed Valve) opens axially downstream of the heat exchanger 18 into the tertiary vein 16. It provides a discharge function by returning part of the primary flow F1 to the tertiary flow F3 to prevent the high pressure compressor 15 from clogging when the flow rate of the primary flow F1 becomes too low.

[0057] The heat exchanger 18 can extend continuously over 360° in the upstream section 20 of the vein 16 around the longitudinal axis 8 of the turbomachine 2. Preferably, the turbomachine 2 comprises several heat exchangers 18 extending in the tertiary flow vein 16 and subdividing the vein angularly in a discontinuous manner over 360° around the longitudinal axis 8. Each of said exchangers can independently provide a heat exchange function between the air and a fluid.

[0058] A single heat exchanger 18 can combine the cooling of several functions or oil circuits of the turbomachine, and this depending on different parameters linked to the need for cooling the oil, ie, inlet temperatures, flow rates, required outlet temperature or air conditions, the different circuits can be put in thermal contact or insulated. The exchanger 18 and in particular its oil passages can withstand a low oil temperature of up to -54°C.

[0059] The upstream section 20 of the tertiary flow stream 16 comprises an external fairing 24 and an inter-stream cowling 26, at least one of the external fairing 24 and inter-stream cowling 26 being rigidly connected to the exchanger 18. Preferably, the inter-stream cowling 26 is fixed to the exchanger 18. Such a fixing will be detailed later in this description.

[0060] The inter-vein cowling 26 comprises an internal casing 28, arranged axially between the high pressure compressor 15 and the low pressure compressor 17, and comprises, in furthermore, an internal shell 30 arranged downstream of the exchanger 18.

[0061] [Fig.2] represents an enlarged longitudinal sectional view of [Fig.l] showing the exchanger 18 mounted on the internal casing 28 by means of an intermediate piece 40.

[0062] Advantageously, the exchanger 18 comprises a body 32 mounted on the internal casing 28 by means of the intermediate part 40 comprising a wall 42 arranged against said casing 28 and a flange 44 at an upstream edge 41 of said wall 42. The upstream edge 41 has a longitudinal section with a radial portion 46 connecting to the wall 42 and a longitudinal portion 48 parallel to the wall 42.

[0063] In this configuration, the internal casing 28, the longitudinal portion 46 and the internal shell 30 constitute, with the exchanger 18, the radially internal guide wall 13 of the tertiary flow F3. Indeed, the longitudinal portion 48 is arranged substantially flush with the radially internal guide wall 13, so as to follow the aerodynamic line 16.1 of the air flow in the tertiary flow vein 16.

[0064] Preferably, the turbomachine 2 comprises a plurality of exchangers 18 which are advantageously distributed angularly in the tertiary flow vein 16.

[0065] The turbomachine 2 comprises structural arms 34 extending radially across the tertiary flow stream 16 and delimiting between them inter-arm spaces 36. Preferably, the turbomachine 2 comprises between 2 and 20 structural arms 34.

[0066] At the same time, the inner ferrule 30 can be single-piece and circumferentially continuous over 360°, or said ferrule can be subdivided into several internal ferrules of up to 5 ferrules.

[0067] The exchanger 18 is preferably obtained by additive manufacturing, said exchanger 18 extending circumferentially between two structural arms 34 in each inter-arm space 36.

[0068] The exchanger 18 comprises heat exchange surfaces 38 corresponding to oil passages and / or heat exchange surfaces with air extending radially and axially in the inter-arm space 36. An example of possible designs is detailed in patent applications BE2021 / 5978, BE2021 / 5979, BE2021 / 5980, BE2021 / 5982 and BE2021 / 5983, the design of the heat exchange surfaces 38 or of the internal oil passages not being the core of the present invention.

[0069] The exchanger 18 also comprises a downstream portion 50 arranged downstream and which can be mounted in a cantilevered manner. This downstream portion 50 has an internal surface with an internal profile 50.1, for example cylindrical or conical, around the longitudinal axis of the turbomachine, and a downstream surface having a downstream profile 50.2 substantially perpendicular to the longitudinal axis.

[0070] The mounting of the downstream part 50 in the tertiary flow vein is not the subject of the present application. The internal shell 30 of the inter-vein cowling 26 can be supported by the exchanger 18 as disclosed in patent applications FR2209649 and FR2209655. Alternatively, the shape of the downstream part 50 may be freer, as inspired by document EP3 674531A1.

[0071] Preferably, the downstream surface 50.2 of the exchanger 18 comprises an oil inlet at one circumferential end of the body 32, and an oil outlet at a circumferentially opposite end.

[0072] Preferably, the oil inlet and the oil outlet are fluidically connected to an oil collector and an oil distributor arranged in an internal part of the body 32 of the exchanger 18 (not shown). The internal part of the body 32 may be hollow and devoid of material (apart from the oil collector and distributor and the fluid connections), so as to lighten the exchanger 18.

[0073] [Fig. 3] represents a perspective view of the intermediate part 40 preferably having a transverse profile in an arc of a circle coaxial with the tertiary flow vein.

[0074] The intermediate piece 40 extends circumferentially over at least 80% of a total circumferential extent of the heat exchanger (not shown here), and more preferably extends over the entire circumferential extent of the exchanger. Thus, the profile of the intermediate piece 40 matches that of the body of the exchanger.

[0075] In this configuration, the body of the exchanger is engaged with the intermediate part, preferably at the level of the flange 44 at the upstream edge 41 of the wall 42. In this respect, the body of the exchanger comprises indexing pins at the right of its upstream part, which extend projecting and upstream from the body.

[0076] For this purpose, the exchanger is indexed on the intermediate part 40 by means of the indexing pins, which allows easy assembly, by a simple manual movement downstream of the exchanger in the tertiary flow vein of the turbomachine.

[0077] The flange 44 has housings 44.1, 44.2 for positioning the indexing pins of the upstream part of the body of the exchanger. It can be seen that the housings 44.1 are reinforced, by continuity of material around the pin, so as to allow the forces of the exchanger to be taken up by the intermediate part 40 and by the internal casing. While the housings 44.2 correspond to openings towards a hollow part 44.3 of the flange 44. Such a design makes it possible to optimize the total mass of the intermediate part 40.

[0078] The intermediate part 40 may be made in a foundry or obtained by additive manufacturing, e.g. 3D printing, or may correspond to an organic matrix composite (OMC) material. Preferably, the intermediate part 40 is made of titanium, and only the functional surfaces are machined.

[0079] [Fig. 4] represents a longitudinal sectional and perspective view of the intermediate part 40 comprising a layer of flexible material 52 contacting the casing internal 28.

[0080] The wall 42 comprises a radially inner face 42.1 provided with the flexible material 52 making it possible to ensure airtightness, the latter corresponding to an insulating seal 52 extending substantially over a periphery of the wall 42, and preferably bonded to the face 42.1.

[0081] This seal 52 advantageously makes it possible to guarantee the seal between the exchanger and the internal casing 28, so as to avoid air leaks into an inter-vein compartment, and also makes it possible to facilitate the mounting of the part 40 on the casing 28 by allowing radial compression, such mounting will be detailed later in this description.

[0082] Preferably, the seal 52 covers the entire circumference of the inter-arm space 36. In fact, the seal 52 extends axially and circumferentially, so as to cover the periphery of the face 42.1 (apart from the upstream edge 41). Advantageously, this makes it possible to guarantee the seal between the exchanger and the inter-vein compartment over the entire surface separating two structural arms 34.

[0083] In this configuration, the seal 52 is arranged to bear against a frame 28.1 of the casing 28, said frame 28.1 preferably coming from the same material as each structural arm 34, it is better represented in [Fig.5].

[0084] With reference to [Fig.5], it is possible to better distinguish the frame 28.1 on which the insulating seal 52 rests.

[0085] The inclination of the intermediate part 40 can also be seen, because [Fig.5] represents a moment during the assembly of said part 40 with a hook 28.2 of the internal casing 28. The part 40 is introduced by pivoting obliquely until the engagement of a downstream edge 49 of the wall 42 with the internal casing 28, by contacting under the hook 28.2, the tilting is carried out by bearing directly against the frame 28.1 under the hook 28.2.

[0086] The hook 28.2 may extend circumferentially over the entire circumferential distance between two structural arms 34, or over only a portion, and preferably, over at most half of said distance. The hook 28.2 is preferably arranged at right angles to a central portion of said distance.

[0087] Advantageously, the angular position of the wall 42 is pre-maintained by means of protrusions which fit into corresponding notches provided in the hook 28.2. The protrusions are preferably two in number.

[0088] [Fig.6] shows one of the two protrusions 49.1 extending radially through one of the two corresponding notches 29 formed on the hook 28.2 of the internal casing 28.

[0089] Preferably, the central part of the downstream edge 49 in the circumferential direction extends further radially outwardly so as to come into contact under the hook 28.2 as illustrated in [Fig.5], and ends with two lateral protrusions 49.1 making it possible to ensure pre-maintenance of the intermediate part 40 in a fixed angular position with the internal casing 28 in the tertiary flow vein.

[0090] [Fig.7] represents a perspective and longitudinal sectional view of the turbomachine 2 during the assembly of the intermediate part 40 on the internal casing 28, after the engagement of the protrusions of the downstream edge 49 with the hook of the casing 28.

[0091] In this assembly step, the intermediate part 40 is pressed against the frame 28.1 of the casing 28 and is held in compression using suitable tooling, which may be of the “candle” type, capable of radially separating the intermediate part 40 from the external fairing 24 (as illustrated by the dotted arrows) by applying an overcompression of approximately 0.5 mm to the seal 52 in order to lower the upstream centering radius of the part 40.

[0092] Advantageously, the radial portion 46 of the flange 44 comprises a rib 45 in an arc of a circle coaxial with the tertiary flow vein, said rib 45 projecting upstream from an upstream face 46.1 of the radial portion 46. The overcompression of the seal 52 by radial spacing makes it possible to lower the position of the rib 45 radially, which allows the latter to receive a fixing ring visible in [Fig.8].

[0093] In this [Fig.7], we can see two orifices 34.1 and 40.1 which allow the ring to be screwed together, respectively, with the internal casing 28 and with the intermediate part 40.

[0094] [Fig.8] represents a perspective and longitudinal sectional view of the turbomachine 2 in which the flange 44 of the intermediate part 40 is fixed to the internal casing 28 by means of the ring 54 arranged against the upstream face of the radial portion 46 and fixed to the internal casing 28.

[0095] The ring 54 is brought from upstream to downstream against the upstream face 46.1, the tooling is then gradually released until the arcuate rib 45 radially supports the ring 54 by a radially external support against a lower edge 54.1 of the ring 54. Such support is ensured by the seal 52 which returns to its initial shape before compression. In this configuration, the orifices 40.1 are aligned with corresponding orifices on the ring 54. For this purpose, precise centering of the exchanger can be obtained thanks to a controlled position of the rib 45 of the intermediate part 40. The spacing tooling can then be removed to allow screw fixing of the ring 54 to the part 40 and to the casing 28.

[0096] Preferably, the ring 54 is continuous circumferentially over 360° around the longitudinal axis of the turbomachine, which thus allows it to fix the internal casing 28 with a plurality of intermediate parts 40. Advantageously, the seal is then guaranteed over the entire circumference of the tertiary flow vein. This allows to avoid any risk of air leaks into the inter-vein compartment.

[0097] The ring 54 further comprises hooks 54.2 extending in a projecting direction downstream, and intended to radially support each of the structural arms 34. Thus, the position of each intermediate part 40 is controlled and can be determined using a dimension chain.

[0098] Advantageously, the exchanger can be easily positioned in the tertiary flow stream. Indeed, the exchanger can be installed by an axial displacement upstream until the insertion of its indexing pins in the flange 44, and until the contact of said flange 44 with the body of the exchanger. It is then a floating assembly devoid of any fixing, allowing, in the event of thermal expansion of the exchanger, to protect the internal casing 28 from any deformation by allowing possible expansions of its downstream part in the axial, radial and circumferential directions.

[0099] Similarly, the exchanger 18 is able to be easily removed by moving axially downstream, by simple manual removal disengaging the indexing pins from their respective housings from the flange 44.

[0100] Advantageously, the turbomachine 2 of the invention makes it possible, by means of the intermediate part 40, to effectively guarantee airtightness between the tertiary flow vein and the internal compartment, to constitute a part of the tertiary flow vein thanks to the longitudinal wall 48 ensuring the guidance of the tertiary flow between the exchanger and the upstream part of the internal casing, as well as to facilitate the assembly and disassembly of the exchanger in the turbomachine, while ensuring precise centering of said exchanger.

Claims

Claims

1. Axial turbomachine (2), comprising: - a first separation nozzle (10) capable of separating an incoming air flow (F) into a radially internal air flow (F') and a radially external air flow (F2), called secondary flow (F2); - a second separation nozzle (14) capable of separating the radially internal air flow (F') into a primary flow (F1) and a tertiary flow (F3), the latter traveling through a tertiary flow vein (16) radially external to a primary flow vein (21) traversed by the primary flow (F1); - a heat exchanger (18) arranged in the tertiary flow vein (16); and - an internal casing (28) radially internally delimiting the tertiary flow vein (16);the turbomachine (2) being characterized in that the at least one heat exchanger (18) comprises a body (32) mounted on the inner casing (28) by means of at least one intermediate part (40) comprising a wall (42) arranged against the inner casing (28) and a flange (44) at an upstream edge (41) of said wall (42), the body (32) engaging with said flange (44).;

2. Turbomachine (2) according to claim 1, characterized in that the at least one intermediate part (40) has a transverse profile in an arc of a circle corresponding to the tertiary flow vein (16).

3. Turbomachine according to one of claims 1 and 2, characterized in that the flange (44) has a longitudinal section with a radial portion (46) connecting to the wall (42) and a longitudinal portion (48) parallel to the wall (42).

4. Turbomachine (2) according to claim 3, characterized in that the radial portion (46) of the flange (44) is fixed to the internal casing (28) by means of a ring (54) arranged against an upstream face (46.1) of said radial portion (46) and fixed to the internal casing (28).

5. Turbomachine (2) according to claim 4, characterized in that the radial portion (46) of the flange (44) comprises a rib (45) in an arc of a circle corresponding to the tertiary flow vein (16) and engaging with a lower edge (54.1) on the ring (54).

6. Turbomachine (2) according to one of claims 1 to 5, characterized in that the wall (42) comprises a downstream edge (49) engaging by pivoting the at least one intermediate part (40) during assembly. with at least one hook (28.2) of the internal casing (28).

7. Turbomachine (2) according to one of claims 1 to 6, characterized in that the at least one intermediate part (40) comprises on a radially inner face (42.1) of the wall (42) a layer of flexible material (52) contacting the internal casing (28) so as to ensure airtightness.

8. Turbomachine (2) according to one of claims 1 to 7, comprising structural arms (34) extending radially in the tertiary flow vein (16), the at least one heat exchanger (18) and the at least one intermediate part (40) being arranged between at least two adjacent structural arms (34) of said structural arms (34).

9. Turbomachine (2) according to one of claims 1 to 8, comprising the body (32) comprising an upstream part provided with indexing pins extending projecting and upstream from the body (32), the at least one exchanger (18) being indexed on the at least one intermediate part (40) by means of said indexing pins.

10. Method for dismantling an exchanger (18) in a turbomachine (2) according to one of claims 1 to 9, the method comprising removing the exchanger (18) by moving it axially downstream.

11. Disassembly method according to claim 10, in which the axially downstream movement disengages indexing pins of the body (32) of the exchanger (18) from the intermediate part (40).

12. Method for mounting an exchanger (18) in a turbomachine (2) according to one of claims 1 to 9, the method comprising the following steps: - fixing the intermediate part (40) on the internal casing (28); - installing the exchanger (18) by moving it axially upstream.

13. Mounting method according to claim 12, in which the axially upstream movement engages indexing pins of the body (32) of the exchanger (18) with the intermediate part (40).

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