Three-flow turbine engine with a heat exchanger in the third flow mounted on an inter-flow compartment

Abstract

The invention relates to a turbine engine (2) comprising: a splitter capable of splitting a radially internal air flow into a primary flow and a tertiary flow, wherein the latter passes through a tertiary flow path (16) radially external to a primary flow path travelled by the primary flow; a heat exchanger (18) arranged in the tertiary flow path; and an inner casing; the turbine engine being characterised in that the at least one heat exchanger 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 and a flange (44) at an upstream edge (41) of the wall, wherein the body engages with the flange.

Description

[0001] DESCRIPTION

[0002] TITLE: TRIPLE-FLOW TURBOMACHINE WITH A HEAT EXCHANGER IN THE THIRD FLOW MOUNTED ON A

[0003] INTER-VEINE COMPARTMENT

[0004] Technical field of the invention

[0005] The invention relates to the field of turbomachinery and more particularly to multiflow turbomachinery. The invention concerns the arrangement of a heat exchanger for cooling the turbomachine oil.

[0006] Technical background The technical background includes in particular the documents FR-A1-3 140 135, FR-A1-2 990 001, US-B2-1 ,510,945 and US-A1-2018 / 347468.

[0007] Climate change is a major concern for many legislative and regulatory bodies worldwide. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by different countries. In particular, an ambitious standard applies to both new types of aircraft and those already in service, requiring the implementation of technological solutions to bring them into compliance with current regulations.

[0008] Civil aviation has been mobilizing for several years now to contribute to the fight against climate change.

[0009] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the factors impacting all phases of design and development in order to obtain less energy-intensive and 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.

[0010] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes that minimize greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0011] This sustained research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to provide propulsion, and, as essential complements to technological progress, aviation biofuels.

[0012] In this context, the invention relates more specifically to aspects concerning the arrangement of heat exchangers in turbomachinery. Indeed, in a turbomachine, it is generally necessary to cool the oil in the lubrication circuit. It is known to place one or more heat exchangers in the tertiary flow of a three-flow turbomachine, that is, in the radially intermediate flow between the primary flow directed towards the combustion chamber and the secondary or external flow.

[0013] Integrating a heat exchanger into the third flow, confined between the primary and secondary or external flows, presents assembly and accessibility challenges for maintenance, as well as constraints related to sealing during operation due to the heat exchanger's thermal expansion. A "brick" type heat exchanger, inspired by document FR 3 089 248 A1, does not meet these constraints and is therefore unsuitable for the third flow. Integrating a heat exchanger into the third flow of a three-flow turbomachine thus presents challenges related to its size, assembly, accessibility, operation, and also the overall mass of the means used to attach it to the casing. Summary of the invention

[0014] The present invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More specifically, the invention aims to provide a simple, efficient, and economical solution to address the disadvantages of prior art turbomachinery design and manufacturing. In particular, the invention aims to provide a solution that enables efficient cooling within a compact footprint while ensuring accessibility to the heat exchanger during maintenance and guaranteeing a tight seal, all without adding mass or compromising the turbomachine's efficiency.

[0015] To this end, the present invention relates to an axial turbomachine, comprising:

[0016] - a first separation nozzle capable of separating an incoming airflow into a radially internal airflow and a radially external airflow, called secondary flow;

[0017] - a second separation nozzle capable of separating the radially internal airflow into a primary flow and a tertiary flow, the latter running through a tertiary flow vein radially external to a primary flow vein through which the primary flow flows;

[0018] - at least one heat exchanger located in the tertiary flow stream; and

[0019] - an internal casing radially delimiting internally the tertiary flow vein; the turbomachine being notable in that at least one heat exchanger comprises a body mounted on the internal casing by means of at least one intermediate part comprising a wall disposed against the internal casing and a flange at an upstream edge of said wall, the body engaging with said flange.

[0020] In this application, the terms "internal," "external," "inner," "outer," "lower," "upper," "radial," "axial," etc., refer to a positioning relative to the longitudinal axis of rotation of a turbomachine. For example, the axial direction corresponds to the direction along the longitudinal axis of rotation of the turbomachine, and the radial direction is perpendicular to the longitudinal axis. Upstream and downstream refer to the direction of flow within the turbomachine.

[0021] Advantageously, the body's connection to the flange is unrestricted, thus preventing the creation of areas of mechanical stress when the heat exchanger undergoes thermal expansion. To this end, the assembly of the body of at least one heat exchanger with at least one intermediate component allows for expansion deformations along the axial, radial, and circumferential directions.

[0022] The internal casing preferably corresponds to an inter-blade cowling of the turbomachine which is located between the primary flow stream and the tertiary flow stream.

[0023] According to an advantageous embodiment of the invention, at least one intermediate piece has a transverse profile in the form of a circular arc corresponding to the tertiary flow vein. The term "corresponding" can be translated here as: "coaxial to",

[0024] 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.

[0025] 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 guiding wall for the tertiary flow.

[0026] According to an advantageous embodiment of the invention, the radial portion of the flange is fixed to the inner casing by means of a ring disposed against an upstream face of said radial portion and fixed to the inner casing.

[0027] According to an advantageous embodiment of the invention, the radial portion of the flange comprises a circular arc rib corresponding to the tertiary flow vein and engaging with a lower edge on the ring or with an upper edge of the ring. The term "corresponding" can be translated here as: "coaxial to".

[0028] Preferably, the arc-shaped rib extends upstream from the upstream face of the radial portion, said rib radially supporting the ring or the ring supporting said rib.

[0029] According to an advantageous embodiment of the invention, the wall comprises a downstream edge which engages by pivoting of at least one intermediate piece during assembly with at least one hook of the internal housing.

[0030] According to an advantageous embodiment of the invention, the wall comprises a downstream edge including a circular arc rib corresponding to the tertiary flow vein and engaging with an upper edge of the internal casing.

[0031] Preferably, the arc-shaped rib extends in projection downstream, with the internal casing supporting this rib.

[0032] Advantageously, the downstream edge of the wall includes at least one protrusion extending radially through at least one corresponding notch formed on at least one hook of the housing, said at least one protrusion ensuring a fixed angular positioning (along the circumferential direction) of the intermediate piece with the inner housing.

[0033] According to an advantageous embodiment of the invention, at least one intermediate piece comprises on a radially inner face of the wall a layer of flexible material contacting the inner casing so as to ensure airtightness.

[0034] Advantageously, said layer of flexible material extends continuously over an entire periphery of the wall.

[0035] Preferably, the flexible material layer corresponds to an insulating gasket extending substantially around the periphery of the wall of at least one intermediate piece. This gasket advantageously ensures a seal between the heat exchanger and the inner casing, thus preventing air leaks into an inter-flow compartment, while avoiding the need for additional fasteners to attach the upstream part of the heat exchanger to the casing, which would otherwise stiffen the exchanger and prevent deformation. Preferably, the flexible material layer or gasket has a generally rectangular shape.

[0036] According to an advantageous embodiment of the invention, the turbomachine comprising structural arms extending radially in the tertiary flow vein, at least one heat exchanger and at least one intermediate piece being disposed between at least two adjacent structural arms of said structural arms.

[0037] The structural arms define inter-arm spaces around the tertiary flow path. Preferably, at least one heat exchanger comprises a plurality of heat exchangers, each of said heat exchangers being indexed to a respective intermediate piece in each inter-arm space, and each of the intermediate pieces comprising an insulating gasket extending at least circumferentially within the inter-arm spaces. Advantageously, the insulating gasket ensures sealing and thermal insulation over 360° around the longitudinal axis.

[0038] According to an advantageous embodiment of the invention, the body comprising an upstream part provided with indexing pins extending in projection and upstream from the body, at least one exchanger being indexed on at least one intermediate part by means of said indexing pins.

[0039] Advantageously, the indexing pins allow simplified fixing of at least one exchanger in the tertiary flow vein.

[0040] In this configuration, at least one heat exchanger is advantageously mounted directly on at least one intermediate part; such mounting is carried out from downstream to upstream, and by simple insertion, thus facilitating the accessibility of the heat exchanger and its maintainability.

[0041] According to an advantageous embodiment of the invention, at least one intermediate piece comprises on a radially external face of the wall stiffening ribs which extend from the flange to a downstream edge of the wall.

[0042] According to an advantageous embodiment of the invention, at least one intermediate piece comprises upstream blind holes opening inwards and suitable for receiving first screws, and downstream through holes oriented parallel to the blind holes and suitable for receiving second screws.

[0043] Preferably, blind holes and orifices are oriented radially.

[0044] The first screws can be screwed in from the inside and the second set of screws can be screwed in from the outside.

[0045] Preferably, the second set of screws have heads hidden by at least one heat exchanger.

[0046] Advantageously, the at least one intermediate part includes upstream a first radial guiding surface oriented upstream, and downstream a second radial guiding surface oriented downstream, the two radial guiding surfaces being parallel and capable of guiding the at least one intermediate part during its assembly in the radial direction.

[0047] 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.

[0048] According to an advantageous embodiment of the invention, the axially downstream displacement disengages the indexing pins of the exchanger body from the intermediate piece.

[0049] Advantageously, the dismantling of the exchanger is partly facilitated by means of indexing pins inserted in a floating manner into corresponding housings arranged at the flange, and requiring only a simple manual removal downstream.

[0050] The invention also relates to a method for installing a heat exchanger in a turbomachine according to the invention, the method comprising the following steps

[0051] - fixing the intermediate part onto the internal casing;

[0052] - installation of the heat exchanger by moving it axially upstream.

[0053] According to an advantageous embodiment of the invention, axial movement upstream engages indexing pins of the heat exchanger body with the intermediate component. Advantageously, the heat exchanger, in addition to efficiently cooling the oil by exchanging heat with the air, ensures the aerodynamic continuity of the tertiary flow, and does so in a sealed manner, preventing any risk of air leakage into the inter-flow compartment. In this configuration, the number of intermediate components that would have been required to separately perform the various functions is significantly reduced, thus decreasing the mass and manufacturing cost of the turbomachine of the invention. Furthermore, the assembly and disassembly of the heat exchanger are facilitated, thereby improving the maintainability of the turbomachine.

[0054] Furthermore, the invention is particularly advantageous because positioning the heat exchanger within the tertiary flow path prevents any degradation of engine efficiency. This results in improved energy efficiency and optimized thrust, which advantageously reduces fuel consumption and greenhouse gas emissions, thus minimizing the environmental impact of aircraft.

[0055] It is understood that each detail of an embodiment below can be combined with each other detail of the other embodiments.

[0056] Brief description of the figures

[0057] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0058] [Fig. 1] represents a longitudinal cross-sectional view of a turbomachine according to the invention, said turbomachine comprising a heat exchanger in a tertiary flow channel;

[0059] [Fig. 2] shows an enlarged longitudinal cross-sectional view of Figure 1 showing the heat exchanger mounted on the inner casing by means of an intermediate piece; and illustrates a first embodiment of the invention; [Fig. 3] shows a perspective view of the intermediate piece comprising a wall and a flange at an upstream edge of said wall; and illustrates the first embodiment of the invention;

[0060] [Fig. 4] represents a longitudinal and perspective cross-sectional view of the intermediate part comprising a layer of flexible material contacting the internal casing; and illustrates the first embodiment of the invention;

[0061] [Fig. 5] represents a longitudinal and perspective cross-sectional view of the intermediate piece comprising a downstream edge engaging by pivoting of said intermediate piece during assembly with a hook of the internal housing; and illustrates the first embodiment of the invention;

[0062] [Fig. 6] represents a perspective view of the downstream edge of the intermediate part of figure 5, comprising a protrusion extending radially through a corresponding notch formed on the hook of the inner housing; and illustrates the first embodiment of the invention;

[0063] [Fig. 7] represents a perspective and longitudinal sectional view of the turbomachine during the mounting of the intermediate part on the inner casing; and illustrates the first embodiment of the invention;

[0064] [Fig. 8] represents a perspective and longitudinal sectional view of the turbomachine in which the flange of the intermediate part is fixed to the inner casing by means of a ring disposed against an upstream face of said flange and fixed to the inner casing; and illustrates the first embodiment of the invention;

[0065] [Fig. 9] represents a perspective and longitudinal sectional view of the heat exchanger, the intermediate piece and the ring; and illustrates a second embodiment of the invention;

[0066] [Fig. 10] represents a perspective and longitudinal sectional view of the inner casing, the intermediate piece and the ring; and illustrates the second embodiment of the invention;

[0067] [Fig. 11] shows a perspective view of the outer face of the intermediate piece; and illustrates the second embodiment of the invention; [Fig. 12] shows a partial perspective view of the flange and the front face of the intermediate piece; and illustrates the second embodiment of the invention;

[0068] [Fig. 13] represents a perspective view of the inner face of the intermediate piece; and illustrates the second embodiment of the invention;

[0069] [Fig. 14] represents a perspective and longitudinal sectional view of the inner casing, the intermediate piece and the ring; and illustrates the second embodiment of the invention;

[0070] [Fig. 15] shows a perspective and longitudinal sectional view of the inner casing, the intermediate piece, and the ring; and illustrates an assembly step of the second embodiment of the invention; and

[0071] [Fig. 16] represents a perspective and longitudinal sectional view of the inner casing, the heat exchanger, the intermediate piece and the ring; and illustrates another assembly step of the second embodiment of the invention.

[0072] Detailed description of the invention

[0073] In the following description, the terms "internal" and "external" refer to positioning relative to the longitudinal axis of rotation of a turbomachine. The axial direction corresponds to the direction along the turbomachine's longitudinal axis of rotation. The radial direction is perpendicular to the longitudinal axis. Upstream and downstream refer to the direction of flow within the turbomachine.

[0074] The figures show the elements schematically and are not drawn to scale. In particular, some dimensions are enlarged to facilitate reading the figures.

[0075] Figure 1 illustrates a turbomachine 2 comprising a propeller 4 attached to a hub 6 rotating around a longitudinal axis 8.

[0076] The turbomachine 2 operates within an airflow F, the relative motion of which is generated by the rotation of the propeller 4 and the forward motion of the aircraft on which the turbomachine 2 is mounted. The airflow F is separated by a first separating nozzle 10 into a radially internal airflow F' and a radially external airflow F2, referred to as the secondary flow F2.

[0077] The propeller 4 can be positioned upstream of the first separation nozzle 10 or downstream.

[0078] The radially internal airflow F' optionally passes through a movable wheel (not shown) which directs it to a second separation nozzle 14 capable of separating the radially internal airflow F' into a primary flow F1 and a tertiary flow F3, the latter being distinct from the secondary flow F2.

[0079] The first separation nozzle 10 includes an internal wall forming a first external guide wall 11 of the radially internal airflow F', said first external guide wall 11 forming a convex profile seen from said radially internal airflow F'.

[0080] The second separation nozzle 14 comprises an external wall forming a second external guide wall 13 of the radially internal airflow F', said second external guide wall 13 forming a convex profile viewed 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.

[0081] The tertiary flow F3 enters a tertiary flow vein 16 radially external to the primary flow F1. The tertiary flow F3 passes through a heat exchanger 18 arranged in the tertiary flow vein 16.

[0082] The heat exchanger 18 extends radially and axially in the tertiary flow vein 16, and preferentially in an upstream section 20 of the tertiary flow vein 16, presenting a longitudinal section diverging in the direction of the flow of the tertiary flow F3.

[0083] The heat exchanger 18 is arranged axially approximately between the high-pressure compressor 15 and the low-pressure compressor 17, called "booster" 17, at the right of an inter-compressor casing.

[0084] The high pressure compressors 15 and low pressure compressors 17 include rotating vanes and straightener vanes arranged in a primary flow channel 21 through which the primary flow F1 passes, the latter heading towards a combustion chamber 23.

[0085] 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 redirecting 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.

[0086] 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.

[0087] Preferably, the turbomachine 2 comprises several heat exchangers 18 extending in the tertiary flow channel 16 and subdividing the channel angularly in a discontinuous manner over 360° around the longitudinal axis 8. Each of said exchangers can independently perform a heat exchange function between air and a fluid.

[0088] A single heat exchanger 18 can combine the cooling of several functions or oil circuits of the turbomachine, depending on various parameters related to the oil cooling requirements, i.e., inlet temperatures, flow rates, required outlet temperature, or air conditions. The different circuits can be thermally connected or isolated. The heat exchanger 18, and in particular its oil passages, can withstand oil temperatures as low as -54°C.

[0089] The upstream section 20 of the tertiary flow vein 16 comprises an external fairing 24 and an inter-vein cover 26, at least one of the external fairing 24 and inter-vein cover 26 being rigidly connected to the exchanger 18. Preferably, the inter-vein cover 26 is fixed to the exchanger 18. Such a fixing will be detailed later in this description.

[0090] The inter-vein cover 26 includes an internal casing 28, arranged axially between the high-pressure compressor 15 and the low-pressure compressor 17, and further includes an internal ferrule 30 arranged downstream of the exchanger 18.

[0091] Figure 2 represents an enlarged longitudinal cross-sectional view of Figure 1 showing the exchanger 18 mounted on the inner casing 28 by means of an intermediate piece 40.

[0092] Advantageously, the heat exchanger 18 comprises a body 32 mounted on the inner casing 28 by means of the intermediate piece 40 comprising a wall 42 disposed against said casing 28 and a flange 44 to 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.

[0093] In this configuration, the inner casing 28, the longitudinal portion 46 and the inner ferrule 30 together with the heat exchanger 18 constitute the internal radially guiding wall 13 of the tertiary flow F3. Indeed, the longitudinal portion 48 is positioned substantially flush with the internal radially guiding wall 13, so as to follow the aerodynamic line 16.1 of the airflow in the tertiary flow channel 16.

[0094] Preferably, the turbomachine 2 comprises a plurality of exchangers 18 which are advantageously distributed angularly in the tertiary flow vein 16.

[0095] The turbomachine 2 comprises structural arms 34 extending radially through the tertiary flow vein 16 and delimiting between them inter-arm spaces 36. Preferably, the turbomachine 2 comprises between 2 and 20 structural arms 34.

[0096] In parallel, the inner ferrule 30 can be monobloc and circumferentially continuous over 360°, or said ferrule can be subdivided into several inner ferrules up to 5 ferrules.

[0097] The heat exchanger 18 is preferably obtained by additive manufacturing, said heat exchanger 18 extending circumferentially between two structural arms 34 in each inter-arm space 36. The heat 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 the internal oil passages not being the focus of the present invention.

[0098] The heat exchanger 18 also includes a downstream portion 50 that can be cantilevered. 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. Mounting the downstream portion 50 in the tertiary flow channel is not the subject of this application. The internal shell 30 of the inter-flow casing 26 can be supported by the heat exchanger 18 as disclosed in patent applications FR2209649 and FR2209655. Alternatively, the shape of the downstream portion 50 can be more freely determined, as inspired by document EP 3 674 531 A1. Preferably, the downstream surface 50.2 of the exchanger 18 includes an oil inlet at one circumferential end of the body 32, and an oil outlet at one circumferentially opposite end.

[0099] Preferably, the oil inlet and outlet are fluidically connected to an oil collector and an oil distributor located within an internal portion of the body 32 of the heat exchanger 18 (not shown). The internal portion of the body 32 may be hollow and free of material (apart from the oil collector and distributor and the fluid connections), in order to reduce the weight of the heat exchanger 18.

[0100] Figures 2 to 8 illustrate a first embodiment of the invention and in particular of the intermediate part 40. Figure 3 represents a perspective view of the intermediate part 40 preferably presenting a transverse profile in the form of a circular arc coaxial with the tertiary flow vein.

[0101] The intermediate piece 40 extends circumferentially over at least 80% of the total circumferential area of ​​the heat exchanger (not shown here), and more preferably over the entire circumferential area of ​​the exchanger. Thus, the profile of the intermediate piece 40 matches that of the body of the exchanger.

[0102] In this configuration, the body of the exchanger is engaged with the intermediate piece, preferably at the flange 44 at the upstream edge 41 of the wall 42. In this respect, the body of the exchanger includes indexing pins at the right of its upstream part, which extend in projection and upstream from the body.

[0103] For this purpose, the exchanger is indexed to the intermediate part 40 by means of indexing pins, which allows for easy assembly by a simple manual movement downstream of the exchanger in the tertiary flow path of the turbomachine.

[0104] The flange 44 has recesses 44.1 and 44.2 for positioning the indexing pins of the upstream part of the heat exchanger body. It can be seen that the recesses 44.1 are reinforced by continuous material around the pin to allow the intermediate part 40 and the internal casing to transfer the heat exchanger stresses. The recesses 44.2 correspond to openings leading to a hollow portion 44.3 of the flange 44. This design optimizes the overall mass of the intermediate part 40.

[0105] The intermediate part 40 can be cast or obtained by additive manufacturing, e.g., 3D printing, or can be made of an organic matrix composite (OMC). Preferably, the intermediate part 40 is made of titanium, and only the functional surfaces are machined. Figure 4 shows a longitudinal cross-sectional perspective view of the intermediate part 40, which includes a layer of flexible material 52 in contact with the internal housing 28.

[0106] The wall 42 includes a radially inner face 42.1 provided with the flexible material 52 to ensure airtightness, the latter corresponds to an insulating joint 52 extending substantially over a periphery of the wall 42, and preferably glued to the face 42.1.

[0107] This seal 52 advantageously ensures the sealing between the exchanger and the internal casing 28, so as to prevent air leaks in an inter-vein compartment, and also facilitates the mounting of part 40 on the casing 28 by allowing radial compression; such mounting will be detailed later in this description.

[0108] Preferably, the seal 52 covers the entire circumference of the inter-arm space 36. Indeed, the seal 52 extends axially and circumferentially, so as to cover the periphery of the face 42.1 (except for the upstream edge 41). Advantageously, this ensures a seal between the heat exchanger and the inter-vein compartment over the entire surface separating two structural arms 34.

[0109] In this configuration, the joint 52 is positioned to rest against a frame

[0110] 28.1 of the casing 28, said frame 28.1 coming preferentially from material with each structural arm 34, it is better represented in figure 5.

[0111] With reference to figure 5, we can better distinguish the frame 28.1 on which the insulating joint 52 rests.

[0112] The inclination of the intermediate part 40 can also be seen, as Figure 5 represents a moment during the assembly of said part 40 with a hook

[0113] 28.2 of the inner casing 28. Part 40 is inserted by pivoting obliquely until a downstream edge 49 of the wall 42 engages with the inner casing 28, by making contact under the hook 28.2. Tilting is achieved by bearing directly against the frame 28.1 under the hook 28.2. The hook 28.2 may extend circumferentially over the entire circumferential distance between two structural arms 34, or only over a portion, and preferably, over at most half of said distance. The hook 28.2 is preferably positioned at a central portion of said distance.

[0114] 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. Preferably there are two protrusions.

[0115] Figure 6 represents 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 inner housing 28.

[0116] Preferably, the central part of the downstream edge 49 along the circumferential direction extends further radially outwards so as to come to rest under the hook 28.2 as illustrated in figure 5, and terminates with two lateral protuberances 49.1 allowing to ensure pre-maintenance of the intermediate part 40 in a fixed angular position with the internal housing 28 in the tertiary flow vein.

[0117] Figure 7 represents a perspective and longitudinal section view of the turbomachine 2 during the mounting of the intermediate part 40 on the inner casing 28, after the engagement of the protrusions of the downstream edge 49 with the hook of the casing 28.

[0118] In this assembly stage, the intermediate part 40 is pressed onto the frame 28.1 of the housing 28 and is held in compression by means of a suitable tool, which may be of the "candle" type, capable of radially separating the intermediate part 40 from the external fairing 24 (as illustrated by the dashed arrows) by applying an overcompression of about 0.5 mm on the seal 52 in order to lower the upstream centering radius of the part 40.

[0119] Advantageously, the radial portion 46 of the flange 44 includes a rib 45 in the form of a circular arc coaxial with the tertiary flow vein, said rib 45 projecting upstream from an upstream face 46.1 of the radial portion 46. Overcompression of the seal 52 by radial spacing allows the position of the rib 45 to be lowered radially, which allows the latter to receive a fixing ring visible in figure 8.

[0120] Figure 7 shows two orifices 34.1 and 40.1 which allow the ring to be screwed in place, respectively, with the inner casing 28 and with the intermediate piece 40.

[0121] Figure 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 inner casing 28 by means of the ring 54 disposed against the upstream face of the radial portion 46 and fixed to the inner casing 28.

[0122] The ring 54 is brought from upstream to downstream against the upstream face 46.1. The tooling is then gradually released until the curved rib 45 radially supports the ring 54 by means of an external radial bearing against a lower edge 54.1 of the ring 54. This bearing is provided 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 heat exchanger can be achieved thanks to the controlled positioning of the rib 45 of the intermediate part 40. The spreading tooling can then be removed to allow the ring 54 to be screwed to the part 40 and the housing 28.

[0123] Preferably, the ring 54 is continuous circumferentially over 360° around the longitudinal axis of the turbomachine, thus enabling it to secure the inner casing 28 with a plurality of intermediate parts 40. Advantageously, sealing is then guaranteed over the entire circumference of the tertiary flow stream. This prevents any risk of air leaks into the inter-flow compartment.

[0124] The ring 54 further includes hooks 54.2 extending downstream, designed to radially support each of the structural arms 34. Thus, the position of each intermediate piece 40 is controlled and can be determined using a dimensional chain. Advantageously, the heat exchanger can be easily positioned in the tertiary flow path. Indeed, the heat exchanger can be installed by axially moving it upstream until its indexing pins are inserted into the flange 44, and until the flange 44 contacts the body of the heat exchanger. This results in a floating assembly without any fixings, allowing, in the event of thermal expansion of the heat exchanger, the protection of the internal casing 28 from any deformation by permitting potential expansion of its downstream portion in the axial, radial, and circumferential directions.

[0125] Similarly, the exchanger 18 is suitable for easy removal by axial movement downstream, by a simple manual removal disengaging the indexing pins from their respective housings from the flange 44.

[0126] Figures 9 to 15 illustrate a second embodiment of the invention and in particular of the intermediate part 40.

[0127] The preceding description, referring to the first embodiment, applies to the second embodiment insofar as it does not contradict what follows. The description that follows therefore essentially concerns the differences between the first and second embodiments.

[0128] The references shown in figures 9 to 15 refer to the same elements as those previously described.

[0129] Figure 9 shows the heat exchanger 18, represented schematically and in a simplified manner (for example, without its fins defining the aforementioned heat exchange surfaces 38). The heat exchanger 18 is mounted on the intermediate piece 40, which is itself mounted on the ring 54. This figure shows, in particular, the indexing pins of the body 32 of the heat exchanger 18, which are engaged in the recesses 44.2 of the flange 44 of the intermediate piece 40.

[0130] Figure 9 also shows that the flexible material layer 52, or the seal, extends to a lower front edge of the intermediate piece 40. Figure 10 shows the inner casing 28 with the ring 54 and the intermediate piece 40; the heat exchanger 18 is not shown. This figure demonstrates, in particular, that the intermediate piece 40 has, on a radially outer face 42.1' of the wall 42, stiffening ribs 60 extending from the flange 44 to the downstream edge 49 of the wall 42.

[0131] Figures 11 to 14 show in more detail the intermediate piece 40 and its cooperation with the ring 54 and the internal casing 28.

[0132] It can be seen in the figures and in particular in figure 13 that the layer of flexible material 52 or the seal extends continuously over a whole periphery of the wall 42. The seal 52 has a general rectangular shape and is located on the inner face 42.1 of the wall 42 so as to be compressed radially on one side between the part 40 and the inner casing 28, and on the other side between the part 40 and the ring 54.

[0133] In the embodiment shown, the ring 54 comprises a radial wall 54a whose inner periphery is connected to a circular arc wall 54b which extends downstream.

[0134] The radial wall 54a includes orifices or housings 54a1 for mounting pins or similar of the flange 44, which are axially oriented.

[0135] The wall 54b includes an outer surface on which the seal 52 rests and includes radial through holes 61 which are intended to be aligned with blind holes 62 of the flange 44. The blind holes 62 open radially inwards.

[0136] At the downstream edge 49 of the wall 42, the inner casing 28 includes blind holes 63 which open radially outwards and are formed in an outer surface 28a in the shape of an arc of the inner casing 28. The inner casing 28 further includes an outer surface 28b in the shape of an arc of a circle on which the seal 52 is intended to bear. The surface 28b is located upstream of the surface 28a.

[0137] Part 40 includes at its upstream edge 41 a rib 45' in the form of an arc of a circle which is oriented axially upstream and which engages on an upper edge 54.1' of the ring 54. Part 40 and in particular the wall 42 includes at its downstream edge 49 a rib 49' in the form of an arc of a circle which is oriented axially downstream and which engages on the upper edge 28.2' and in particular on the surface 28a of the inner casing 28. This rib 49' may be continuous or discontinuous and may, for example, be formed by a series of tabs as illustrated in the drawings.

[0138] The rib 49' includes radially oriented through holes 65 adapted to receive screws 66 screwed into the aforementioned blind holes 63. Tightening these screws 66 ensures compression of the seal 52 between the wall 52 and the inner casing 28.

[0139] Part 40 and in particular flange 44 includes upstream blind holes 62 which open radially inwards and are suitable for receiving screws 64 screwed into the orifices 61 of the ring 54. Screwing these screws 64 ensures the compression of the seal 52 between the wall 52 and the ring 54.

[0140] Figure 14 shows that the screws 64 are screwed in from the inside, and the screws 66 are screwed in from the outside. This means that the screws 64 have heads that bear radially against the inside of the wall 54b of the ring 54, and that the screws 68 have heads that bear against the outside of the rib 49' of the wall 42. The heads of the screws 68 are intended to be covered and concealed by the heat exchanger 18.

[0141] Preferably, the intermediate part 40 comprises, upstream, a first radial guiding surface 70 oriented upstream, and, downstream, a second radial guiding surface 72 oriented downstream. The two surfaces 70 and 72 are parallel and suitable for guiding the intermediate part 40 during its radial mounting, as illustrated in Figure 15.

[0142] To assemble this component, the ring 54 is first fixed to the inner casing 28. The part 40 is brought axially, as illustrated in Figure 15, between two structural arms 34 of the inner casing 28. The part 40 is then moved radially inwards until its rib 45' bears against the ring 54, and its rib 49' bears against the upper edge 28.1' of the inner casing 28. The aforementioned surfaces 70, 72 guide this movement. The screws 64, 66 are tightened, which compresses the seal 52 and seals the assembly.

[0143] The heat exchanger 18 is then mounted as illustrated in figure 16. It is brought axially between the two structural arms 34 of the inner casing 28 and then fixed to the inner casing 28.

[0144] Advantageously, the turbomachine 2 of the invention allows, by means of the intermediate part 40, to effectively guarantee the airtightness between the tertiary flow stream and the internal compartment, to constitute a part of the tertiary flow stream 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

DEMANDS 1. Axial turbomachine (2), comprising: - a first separation nozzle (10) capable of separating an incoming airflow (F) into a radially internal airflow (F') and a radially external airflow (F2), called secondary flow (F2); - a second separating nozzle (14) capable of separating the radially internal airflow (F') into a primary flow (F1) and a tertiary flow (F3), the latter running through a tertiary flow vein (16) radially external to a primary flow vein (21) through which the primary flow (F1) runs; - at least one heat exchanger (18) disposed in the tertiary flow stream (16); and - an inner casing (28) radially delimiting internally the tertiary flow vein (16); at least one heat exchanger (18) comprising a body (32) mounted on the inner casing (28) by means of at least one intermediate piece (40) comprising a wall (42) disposed 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 the preceding claim, 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).

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

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

5. Turbomachine (2) according to any one of the preceding claims, characterized in that the wall (42) comprises a downstream edge (49) comprising a rib (49') in an arc of a circle corresponding to the tertiary flow vein (16) and engaging on an upper edge (28.2') of the inner casing (28).

6. Turbomachine (2) according to any one of the preceding claims, characterized in that 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 inner casing (28) so as to ensure airtightness, said layer of flexible material (52) extending continuously over a whole periphery of the wall (42).

7. Turbomachine (2) according to any one of the preceding claims, comprising the body (32) including an upstream part provided with indexing pins extending in projection and upstream from the body (32), at least one exchanger (18) being indexed to at least one intermediate part (40) by means of said indexing pins.

8. Turbomachine (2) according to any one of the preceding claims, characterized in that at least one intermediate part (40) comprises on a radially external face (42. T) of the wall (42) stiffening ribs (60) which extend from the flange (44) to a downstream edge (49) of the wall (42).

9. Turbomachine (2) according to any one of the preceding claims, characterized in that at least one intermediate part (40) comprises upstream blind holes (62) opening inwards and suitable for receiving first screws (64), and downstream through orifices (65) oriented parallel to the blind holes (62) and suitable for receiving second screws (66).

10. Turbomachine (2) according to claim 9, characterized in that the second screws (66) have heads hidden by at least one heat exchanger (18).

11. Turbomachine (2) according to any one of the preceding claims, characterized in that the at least one intermediate part (40) comprises upstream a first radial guide surface (70) oriented upstream, and downstream a second radial guide surface (72) oriented downstream, the two radial guide surfaces (70, 72) being parallel and capable of guiding the at least one intermediate part (40) during its assembly in the radial direction.

12. A method for mounting a heat exchanger (18) in a turbomachine (2) according to any one of the preceding claims, the method comprising the following steps: - fixing the intermediate part (40) onto the internal casing (28); - installation of the exchanger (18) by an axial displacement upstream.

13. Assembly method according to the preceding claim, wherein the axial upstream movement engages indexing pins of the body (32) of the exchanger (18) with the intermediate part (40).

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