Heat exchange system for an aircraft turbine engine

Abstract

The invention relates to a heat exchange system (20), in particular for an aircraft turbine engine (1), the system comprising: - an outer annular wall (22) and an inner annular wall (23), respectively; - a first annular heat exchange device (21) which is carried by one of the walls (22), and which comprises a heat exchange matrix (26) positioned between this wall (22) and a cover (27), characterised in that it further comprises: - a second annular heat exchange device (30) which comprises a heat exchange matrix (31) which is axially spaced apart from the heat exchange matrix (26) of the first device (21) and which is positioned between the cover (27) of the first device (21) and the opposite wall (23) or another cover (32) of the second device (30).

Description

[0001] DESCRIPTION

[0002] TITLE: HEAT EXCHANGE SYSTEM FOR AN AIRCRAFT TURBOMACHINE

[0003] Field of invention

[0004] The present invention relates to the general field of cooling, and its application in particular in the field of aeronautics. It relates in particular to a heat exchange system, in particular for a turbomachine, in particular an aircraft.

[0005] Bitter technical plan

[0006] The technical background includes in particular documents US-BI-6,,68,915, EP-A1 -3,196,443 and WO-A1 -2022 / 064136. A turbomachine, in particular an aircraft turbomachine, comprises various components and / or equipment that must be lubricated and / or cooled, such as rolling bearings and gears. The heat released by these components, which can be very significant depending on the power of the component and / or equipment, is transported by a fluid and evacuated to cold sources available in the aircraft. It is known to equip the turbomachine with one or more heat exchange systems to carry out the heat exchange between the fluid (typically oil) and the cold source (air, fuel, etc.).There are even different types of heat exchange systems, for example, fuel / oil heat exchangers, commonly known as FCOC for Fuel Cooled Oil Cooler, and air / oil heat exchangers, commonly known as ACOC for Air-Cooled Oil Cooler.

[0007] FCOC heat exchangers have a dual function of heating the fuel before combustion in the combustion chamber of the turbomachine and cooling the oil heated by the heat dissipation of the turbomachine. However, FCOC heat exchangers are not sufficient to absorb all the heat dissipation because the fuel temperature is limited in view of safety constraints. Additional cooling is obtained by ACOC heat exchangers, in particular those of the surface type and known by the acronym SACOC. Surface heat exchangers are generally arranged in the secondary vein of the turbomachine and use the secondary air flow to cool the oil circulating in the turbomachine. These heat exchangers are in the form of a metal surface part allowing the passage of oil in machined channels.The secondary air flow is guided along a heat exchange matrix carried by this surface part and whose role is to increase the contact surface with the secondary air flow and to extract calories. However, SACOC heat exchangers have the disadvantage of creating additional pressure losses in the secondary vein concerned since they disrupt the air flow which impacts the performance of the turbomachine as well as the specific fuel consumption.

[0008] The Applicant has already proposed a solution to this problem in documents FRAI -3 096 409 and FR-A1 -3 096 444.

[0009] In addition, the cooling requirements of the lubricating fluid are increasing due to the increase in rotational speeds and powers involved to meet specification trends on turbomachines.

[0010] Indeed, ACOC exchangers are increasingly in demand in the future generation of engines due to the significant increase in heat dissipation, mainly due to:

[0011] - to the engines of the future which are larger, which increases the need for lubrication and cooling with oil,

[0012] - the presence of a speed reducer in new motor architectures, this reducer transmitting very high mechanical power and needing to be lubricated and cooled by oil, and

[0013] - the addition of electrical machines on board an engine for hybridization, these machines needing to be lubricated and cooled by oil.

[0014] The engine may have several oil circuits, each with a defined function, for example a first circuit for cooling the oil dedicated to lubricating and cooling the engine, a second for lubricating and cooling the motor reducer, a third for cooling the machines, etc. The oil temperature and flow rate must be controlled according to the corresponding circuit. For example, the oil used to lubricate and cool electrical machines has a different temperature range than that for engine cooling. Thus, the ACOC is preferably divided into several exchangers, each exchanger being dedicated to a given oil circuit. These different exchangers are generally distributed around the longitudinal axis of the engine

[0015] The growing need for cooling has a direct impact on the dimensions of ACOCs. Large heat exchangers are therefore required to evacuate the oil heat. In order to evacuate the oil heat, ACOCs could occupy all the available space in a vein, and thus extend all around the vein and over the entire height or radial dimension of the vein, in order to have the necessary air flow to evacuate the heat at the sizing point, which generally occurs during the takeoff phase in the case of an extremely hot day.

[0016] However, the fact that the ACOC exchangers occupy the entire radial height of the vein prevents the flow passing through the exchanger from being controlled with the solution described in documents FR-A1-3 096 409 and FR-A1-3 096 444.

[0017] As a result, the entire airflow passes through the ACOCs and consequently, each of the ACOCs operates with suboptimal aerothermal performance. This results in a high pressure drop on the air side and leads to inefficient exchangers. The objective of the present invention is to propose an improvement to existing technologies making it possible to optimize the efficiency of heat exchanges while avoiding pressure drops and disturbing the gas flow as little as possible. Summary of the invention

[0018] The invention thus proposes a heat exchange system, in particular for an aircraft turbomachine, this system comprising:

[0019] - two annular walls, respectively external and internal, which extend around each other and around the same axis, and which are configured to define between them a flow vein for a gas flow,

[0020] - a first annular heat exchange device which extends around the axis and is carried by one of said walls, and which is located in the vein, this first device comprising a heat exchange matrix interposed between this wall and a cover which has a predetermined diameter D1 measured at the axial middle of the heat exchange matrix of the first device, characterized in that it further comprises:

[0021] - a second annular heat exchange device which extends around the axis and is located in the vein, this second device comprising a heat exchange matrix which is axially spaced from the heat exchange matrix of the first device and which is interposed between the cover of the first device and the opposite wall or another cover of the second device, the cover of the first device having a predetermined diameter D2 measured at the axial center of the heat exchange matrix of the second device, and in that:

[0022] - D2 is greater than D1 when the first device is carried by the external wall, or

[0023] - D2 is less than D1 when the first device is carried by the internal wall.

[0024] The present invention thus proposes to associate at least two heat exchange devices in the vein and to position these devices so that they are, on the one hand, axially offset from each other and, on the other hand, staggered relative to each other.

[0025] The axial offset of the devices comes from the fact that the heat exchange matrices of the devices are axially spaced from each other. The heat exchange matrix of the first device is thus located upstream or downstream relative to the heat exchange matrix of the second device.

[0026] In this application, the expressions upstream and downstream refer to the flow of air or gases in the vein during normal operation of the turbomachine.

[0027] In the present application, a heat exchange matrix may comprise fins and / or plates and / or tubes. A matrix may be stepped and comprise, for example, a stack of several layers, each of the layers comprising fins, or at least one plate or at least one tube. The fins are intended to be swept by a gas flow, and the plates or tubes are traversed, for example, by an oil circuit or comprise such an oil circuit. The staging of the devices comes from the fact that the devices share a common cover, this cover being advantageously shaped so that a portion of the heat exchange matrix of the second device is axially aligned with a portion of the heat exchange matrix of the first device. In addition to being stepped, the devices may therefore overlap axially.

[0028] The heat exchange system may include one or more of the following features, considered independently of each other or in combination with each other:

[0029] - the cover of the first device comprises several successive axial sections along the axis:

[0030] - an upstream end section which is located upstream of the heat exchange matrix of the second device, a section which extends to the periphery of the heat exchange matrix of the second device, an intermediate section which extends axially between the heat exchange matrix of the second device and the heat exchange matrix of the first device, a section which extends to the periphery of the heat exchange matrix of the first device, and a downstream end section which is located downstream of the heat exchange matrix of the first device, or

[0031] - an upstream end section which extends upstream of the heat exchange matrix of the first device, a section which extends at the periphery of the heat exchange matrix of the first device, an intermediate section which extends axially between the heat exchange matrix of the first device and the heat exchange matrix of the second device, a section which extends at the periphery of the heat exchange matrix of the second device, and a downstream end section which is located downstream of the heat exchange matrix of the second device;

[0032] - the cover of the second device comprises an upstream end section located upstream of the heat exchange matrix of this second device, a section located at the periphery of the heat exchange matrix of this second device, and a downstream end section located downstream of the heat exchange matrix of this second device; - the cover of the second device has a predetermined diameter D3 measured at the axial center of the heat exchange matrix of the second device, and in that D3 is less than or greater than D1;

[0033] - D3 is greater than D1 when the first device is carried by the external wall, or D3 is less than D1 when the first device is carried by the internal wall; this accentuates the staging of the devices and the axial alignment of their heat exchange matrices the cover of the second device has an upstream free end which is located upstream of an upstream free end of the cover of the first device, or which is located between upstream and downstream ends of the intermediate section

[0034] - the system further includes:

[0035] - a third annular heat exchange device which extends around the axis and is located in the vein, this third device comprising heat exchange matrix which is axially spaced from the heat exchange matrix of the first and second devices and which is interposed between the cover of the second device and the other of the walls or another cover of the third device, the cover of the second device having a predetermined diameter D3 measured at the axial middle of the heat exchange matrix of the second device, and a predetermined diameter D4 measured at the axial middle of the heat exchange matrix of the third device, and in that:

[0036] - D4 is greater than D3 when the first device is carried by the external wall, or

[0037] - D4 is less than D3 when the first device is carried by the internal wall;

[0038] - the cover of the third device comprises an upstream end section located upstream of the heat exchange matrix of this third device, a section located at the periphery of the heat exchange matrix of this third device, and a downstream end section located downstream of the heat exchange matrix of this third device;

[0039] - the or each upstream end section forms a divergent, and the or each downstream end section forms a convergent;

[0040] - the end sections have a truncated or rounded shape; - the heat exchange matrix of the first device has a height or radial dimension greater than or equal to that of the heat exchange matrix of the second device;

[0041] - the sum of the heights or radial dimensions of the heat exchange matrix of the first and second devices is less than the height or radial dimension of the vein measured at the level of these devices;

[0042] - the sum of the heights or radial dimensions of the heat exchange matrix of the first and second devices is greater than the height or radial dimension of the vein measured at the level of these devices; - each of the external and internal walls carries a first device of the aforementioned type, which is associated with a second device of the aforementioned type or even with a third device of the aforementioned type;

[0043] - each of the devices is of the ACOC or SACOC type;

[0044] - each divergent and each convergent has a truncated or rounded shape; the rounded shape improves the aerodynamics of the flow bypassing the device, which reduces the pressure losses due to the installation of this assembly. These shapes can be obtained by additive manufacturing for example;

[0045] - the or each cover is independent of the walls of the vein, and is therefore not connected to these walls; - the first heat exchange device is of the surface type, and / or the second heat exchange device is of the surface type, and / or the third heat exchange device is of the surface type;

[0046] - the or each heat exchange device is of the SACOC or ACOC type;

[0047] - the or each hood is at a distance from the walls of the vein so that part of the gas flow flowing in the vein can bypass or bypass the or each heat exchange device.

[0048] The invention further relates to a turbomachine or an electronic device comprising at least one heat exchange system as mentioned above. The present invention can indeed be used for cooling a device

[0049] Brief description of the figures

[0050] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the appended schematic drawings in which:

[0051] [Fig. 1] Figure 1 is a half schematic view in axial section of an example of a turbomachine to which the invention applies;

[0052] [Fig. 2] Figure 2 is a very schematic cross-sectional view of a heat exchange system;

[0053] [Fig. 3] Figure 3 is a very schematic view in axial section of the system of Figure 2;

[0054] [Fig. 4] Figure 4 is another very schematic view of a system similar to that of Figure 3;

[0055] [Fig. 5] Figure 5 is a schematic perspective and partial view of a heat exchange device;

[0056] [Fig. 6a-6b] Figures 6a and 6b are very schematic cross-sectional views of heat exchange systems each comprising a sectorized heat exchange device;

[0057] [Fig. 7] Figure 7 is a very schematic view in axial section of the system of Figure 6a;

[0058] [Fig. 8] Figure 8 is a very schematic axial sectional view of a heat exchange system according to a first embodiment of the invention;

[0059] [Fig. 9] Figure 9 is a very schematic axial sectional view of a heat exchange system according to a second embodiment of the invention;

[0060] [Fig. 10] Figure 10 is a very schematic axial sectional view of a heat exchange system according to a third embodiment of the invention;

[0061] [Fig. 11] Figure 11 is a very schematic axial sectional view of a heat exchange system according to a fourth embodiment of the invention;

[0062] [Fig. 12] Figure 12 is a very schematic axial sectional view of a heat exchange system according to a fifth embodiment of the invention;

[0063] [Fig. 13] Figure 13 is a very schematic axial sectional view of a heat exchange system according to a sixth embodiment of the invention;

[0064] [Fig. 14] Figure 14 is a very schematic axial sectional view of a heat exchange system according to a seventh embodiment of the invention; [Fig. 15] Figure 15 is a very schematic axial sectional view of a heat exchange system according to an eighth embodiment of the invention.

[0065] Detailed description of the invention Figure 1 shows an axial sectional view of a turbomachine with longitudinal axis X to which the invention applies. The turbomachine shown is a double-flow turbomachine 1 intended to be mounted on an aircraft. Of course, the invention is not limited to this type of turbomachine.

[0066] This double flow turbomachine 1 generally comprises a gas generator 2 upstream of which a fan or fan module 3 is mounted.

[0067] In the present invention, the terms “upstream” and “downstream” are defined in relation to the circulation of gases in the turbomachine 1 and here along the longitudinal axis X.

[0068] The gas generator 2 comprises a gas compressor assembly (here comprising a low pressure compressor 4a and a high pressure compressor 4b), a combustion chamber 5 and a turbine assembly (here comprising a high pressure turbine 6a and a low pressure turbine 6b).

[0069] Conventionally, the turbomachine 1 comprises a low pressure shaft 7 which connects the low pressure compressor 4a and the low pressure turbine 6a to form a low pressure body, and a high pressure shaft 8 which connects the high pressure compressor 4b and the high pressure turbine 6b to form a high pressure body.

[0070] The low pressure shaft 7, centered on the longitudinal axis X, here drives a fan shaft 9 by means of a speed reducer 10. Rotating guide bearings 15 also make it possible to guide the low pressure shaft 7 in rotation relative to a fixed structure or stator of the turbomachine. The high pressure shaft 8 is also guided in rotation by guide bearings (not shown).

[0071] The fan 3 is shrouded by a fan casing 11 carried by a nacelle 12 and generates a primary air flow F1 which circulates through the gas generator 2 in a primary vein V1, and a secondary air flow F2 which circulates in a secondary vein V2 around the gas generator 2. The secondary air flow F2 is ejected by a secondary nozzle 13 terminating the nacelle while the primary air flow F1 is ejected outside the turbomachine 1 via an ejection nozzle 14 located downstream of the gas generator 2. In the remainder of the description, the fan casing 11 and the nacelle 12 are considered as a single part.

[0072] The guide bearings 15 and the speed reducer 10 in this example configuration of the turbomachine 1 must be lubricated and / or cooled to ensure the performance of the turbomachine 1. The power generated by them is dissipated in a fluid coming from a fluid supply source installed in the turbomachine 1 and which makes it possible to lubricate and / or cool various components and / or equipment of the turbomachine 1. Of course, other equipment of the turbomachine 1 generates a lot of heat which must be extracted from its environment.

[0073] For this purpose, the turbomachine 1 comprises a heat exchange system 20 which makes it possible to cool the fluid intended to lubricate and / or cool these components and / or equipment. In the present example, the fluid is an oil and the cold source intended to cool the oil is a gas flow circulating in the turbomachine, in particular the secondary air flow F2.

[0074] In the context of the present invention, a heat exchange system 20 is understood to mean a system comprising:

[0075] - two annular walls, respectively external and internal, which extend around each other and around the same axis, and which are configured to define between them a flow vein for a gas flow, and

[0076] - at least one annular heat exchange device located in this vein.

[0077] In the case of Figure 1 for example, the heat exchange system 20 of the turbomachine 1 comprises an external wall 22 formed by the fan casing 11 and / or the nacelle 12, an internal wall 23 formed by a casing of the gas generator 2, and a heat exchange device 21 which is here carried by the external wall 22 and located in the vein V2.

[0078] The heat exchange device 21 is for example of the surface type (for example of the SACOC type) and preferably of the air / oil type.

[0079] The device 21 comprises an oil circuit and a heat exchange matrix located in the vein V2 and configured to be swept by said gas flow F2. As mentioned above, the heat exchange matrix may comprise fins and / or plates and / or tubes. A matrix may be staged and comprise, for example, a stack of several layers, each of the layers comprising fins, at least one plate or at least one tube. The fins are intended to be swept by a gas flow, and the plates or tubes are traversed, for example, by an oil circuit or comprise such an oil circuit.

[0080] Figures 2 and 3 schematically show a heat exchange system 20 of this type. It can be seen that the heat exchange device 21 of this system 20 is annular and extends continuously over 360° around the X axis.

[0081] It is also noted that it occupies only a part of the height H of the vein V2. The device 21 has a height h or radial dimension which represents only a part of the height H or radial dimension of the vein V2. These heights H, h are measured in the radial direction with respect to the X axis, in an area of ​​the vein V2 in which this device 21 is located. The height H of the vein V2 is likely to change along the X axis.

[0082] One of the problems observed in a device 21 of this type is the disturbances and pressure losses generated in the gas flow F2, which has the effect of increasing the specific and fuel consumption of the turbomachine 1. Hence the interest in optimizing the aerothermal performance of this system 20.

[0083] In the aforementioned documents, the Applicant has proposed a solution for optimizing the integration of this type of device 21 in a vein, which is illustrated in Figure 4. The idea is to slow down the speed of the gas flow passing through the device 21. Indeed, the gas flow passing through the device 21 is very turbulent. Slowing down the flow speed of the air flow at the inlet of the device 21 makes it possible to optimize its aerothermal performance and thus minimize the pressure drop for a given heat dissipation. The flow passing through the device 21 can be controlled by associating with the device 21 a divergent 24 at the inlet and a convergent 25.The divergent 24 upstream of the device 21 is configured so as to compress and slow down the flow of gas entering the device 21, and the convergent 25 arranged downstream of the device 21 is configured so as to accelerate and expand the flow of gas leaving the device. Error I Source of the reference not found. At the inlet of the device 21, the slowing down factor is inversely proportional to the ratio of the heights h / hO, h being the aforementioned height and hO being the height at the inlet of the divergent 24. Note that the more the flow is slowed down, the more the pressure drop generated by the device 21 decreases. At the outlet of the device 21, the acceleration factor is inversely proportional to the ratio of the heights h / h3, h3 being the height at the outlet of the convergent 25.

[0084] Figure 5 illustrates in perspective a part of a heat exchange device 21. It shows the heat exchange matrix 26 which is interposed or sandwiched between a cover 27 and the wall 22, 23 which carries this device 21. The convergent 25 and the divergent 24 can be formed by ends of the cover 26, as in the example shown.

[0085] In Figure 5 and the other figures, arrows are used to schematically represent the oil circuit 28.

[0086] Figures 6a and 6b schematically show alternative embodiments of heat exchange systems 20.

[0087] In the case of Figure 6a, the system 20 comprises an annular heat exchange device 21 which is sectorized and comprises two sectors each having an angular extent of approximately 180°.

[0088] In the case of Figure 6b, the system 20 comprises an annular heat exchange device 21 which is sectorized and comprises four sectors each having an angular extent of approximately 90°.

[0089] Furthermore, in these figures 6a-6b, the heat exchange device 21 extends over the entire height H of the vein and is connected to the two walls 22, 23. The height h of the device 21 is then equal to the height H of the vein (figure 7).

[0090] The present invention provides an improvement to this technology and provides several embodiments which are illustrated in Figures 8 and following.

[0091] One of the particularities of the invention is based on the fact that the heat exchange system comprises at least two annular heat exchange devices and that these devices are arranged so as to be staggered and so that their heat exchange matrices are axially spaced from each other.

[0092] In the first embodiment of the invention shown in Figure 8, the heat exchange system 20 comprises:

[0093] - two annular walls, respectively external 22 and internal 23, which extend around each other and around the same axis X, and which are configured to define between them a flow vein V2 of a gas flow, such as a secondary flow F2, - a first annular heat exchange device 21 which extends around the axis X and is carried by one of the walls, here the external wall 22, and which is located in the flow vein V2, this first device 21 comprising a heat exchange matrix 26 interposed between this wall 22 and a cover 27 which has a predetermined diameter D1 measured at the axial center of the heat exchange matrix 26 of this first device 21, and

[0094] - a second annular heat exchange device 30 which extends around the axis X and is located in the vein V2, this second device 30 comprising a heat exchange matrix 31 which is axially spaced from the heat exchange matrix 26 of the first device 21 and which is interposed between the cover 27 of the first device 21 and another cover 32 of the second device 30, the cover 31 of the first device 21 having a predetermined diameter D2 measured at the axial center of the heat exchange matrix 31 of the second device 30.

[0095] It can be seen in Figure 8 that the heat exchange matrices 26, 31 of the devices 21, 30 are spaced axially from each other in the vein V2, by an axial distance noted L. In the example shown, the device 21 located on the external wall 22 is located downstream of the device 30.

[0096] In the embodiment of Figure 8, D2 is greater than D1, that is to say that an external peripheral part of the heat exchange matrix 31 of the second device 30 is aligned in the axial direction with an internal peripheral part of the heat exchange matrix 26 of the first device 21.

[0097] These devices 21, 30 are preferably of the air-oil type and for example of the surface type and each comprise an oil circuit 28 in addition to the heat exchange matrix 26, 31 which are located in the vein V2 and configured to be swept by the gas flow F2, as mentioned above.

[0098] The devices 21, 30 thus have the cover 27 in common.

[0099] The heat exchange matrix 26 of the device 21 is covered by the annular cover 27 which extends axially, here upstream, to form the external cover of the heat exchange matrix 31 of the device 30. This cover 27 is thus located at the internal periphery of the heat exchange matrix 26 of the device 21 and at the external periphery of the heat exchange matrix 31 of the device 30. The heat exchange matrix 31 of the device 30 is further connected to the other cover 32 which is therefore located at the internal periphery of this heat exchange matrix 31.

[0100] The cover 27 of the first device 21 comprises several successive axial sections along the X axis, namely:

[0101] - an upstream end section 27a which is located upstream of the heat exchange matrix 31 of the second device 30,

[0102] - a section 27b which extends to the external periphery of the heat exchange matrix 31 of the second device 30,

[0103] - an intermediate section 27c which extends axially between the heat exchange matrix 31 of the second device 30 and the heat exchange matrix 26 of the first device 21,

[0104] - a section 27d which extends to the internal periphery of the heat exchange matrix 26 of the first device 21, and

[0105] - a downstream end section 27e which is located downstream of the heat exchange matrix 26 of the first device 21.

[0106] The cover 32 of the second device 30 comprises:

[0107] - an upstream end section 32a located upstream of the heat exchange matrix 31 of this second device 30,

[0108] - a section 32b located at the internal periphery of the heat exchange matrix 31 of this second device 30, and

[0109] - a downstream end section 32c located downstream of the heat exchange matrix 31 of this second device 30.

[0110] It can be seen that each of the upstream end sections 27a, 32a forms a divergent, and that each of the downstream end sections 27e, 32c forms a convergent.

[0111] In the example shown, the end sections 27a, 27e, 32a, 32c each have a truncated cone shape.

[0112] The cover 32 of the second device 30 has a predetermined diameter D3 measured at the axial center of the heat exchange matrix 31 of the second device 30. In the example shown, D3 is greater than D1. D3 is also less than D2.

[0113] In Figure 8:

[0114] - H1 represents the diameter at the free upstream end of the cover 32 or of the upstream end section 32a of this cover 32, - H2 represents the diameter at the downstream end of the upstream end section 32a of this cover 32,

[0115] - H3 represents the diameter at the upstream end of the downstream end section 32c of this cover 32,

[0116] - H4 represents the diameter at the free downstream end of the cover 32 or of the downstream end section 32c of this cover 32,

[0117] - H5 represents the diameter at the free upstream end of the cover 27 or of the upstream end section 27a of this cover 27,

[0118] - H6 represents the diameter at the downstream end of the upstream end section 27a of this cover 27,

[0119] - H7 represents the diameter at the upstream end of the intermediate section 27c,

[0120] - H8 represents the diameter at the downstream end of the intermediate section 27c,

[0121] - H9 represents the diameter at the upstream end of the downstream end section 27e of this cover 27, and

[0122] - H10 represents the diameter at the free downstream end of the cover 27 or of the downstream end section 27e of this cover 27.

[0123] These diameters are measured relative to the X axis.

[0124] In the example shown:

[0125] - H1 is greater than or equal to H2, H5 and H6 in particular, H2 could also be the maximum diameter of the system 20,

[0126] - H5 is greater than H2 and H6 in particular, H2 could also be the maximum diameter of the hood 27,

[0127] - H7 is superior to H8, H3 and H4 in particular,

[0128] - H2 and H3 are higher than H8 and H9.

[0129] Each of the devices 21, 30 may comprise a single heat exchanger, or be sectorized and comprise two or more heat exchangers distributed around the X axis, as discussed above.

[0130] In the example shown, the device 21 located on the right in the drawing occupies a height h1 in the vein of between 20 and 50% of the height hv1 of this vein. The device 30 located on the left in the drawing occupies a height h2 in the vein of between 10 and 30% of the height hv2.

[0131] The heat exchange matrix 26 of the first device 21 has a height h3 or radial dimension greater than or equal to that h4 of the heat exchange matrix 31 of the second device 30. The sum of the heights h3, h4 or radial dimensions of the heat exchange matrices 26, 31 of the first and second devices 21, 30 is less than the height hv1, hv2 or radial dimension of the vein V2 measured at the level of these devices 21, 30.

[0132] It is understood that an external peripheral part of the air flow F2 (for example between 5 and 50% of the flow rate) flowing in the vein will be used in the devices 21, 30 and that the remainder of this flow will bypass the devices 21, 30. The air used in the devices will be divided into a first part, internal peripheral (representing for example 2.5 to 25% of the flow rate), which will enter the device 30, and the remainder, the external peripheral part (representing for example 2.5 to 25% of the flow rate), which will enter the device 21.

[0133] The second embodiment illustrated in Figure 9 differs from the first embodiment in particular in that the covers 27, 32 each have a curved or wavy shape.

[0134] Furthermore, in the example shown, D3 is less than D1. In addition, H2 and H3 are less than H8 and H9.

[0135] In the example shown, it can be seen that the section of the cover 27, which extends to the periphery of the heat exchange matrix of the second device 30, has a hollow oriented towards the side of the internal wall 23. The cover 27 then has a generally curved or wave-like shape in section. It can also be seen that the cover 32, on the contrary, is essentially curved towards the side of the internal wall 23.

[0136] The operation of the system in Figure 9 is similar to that in Figure 8.

[0137] The third embodiment illustrated in Figure 10 differs from the second embodiment in particular in that, in addition to the devices 21, 30 located at the external wall 22, similar devices 21', 30' are located at the internal wall 23.

[0138] Thus, the heat exchange system 20 additionally comprises devices 21, 30

[0139] - another first annular heat exchange device 2T which extends around the axis X and is carried by the internal wall 23, and which is located in the vein V2, this first device 21 comprising a heat exchange matrix 26' interposed between this wall 23 and a cover 27' which has a predetermined diameter D1' measured at the axial center of the heat exchange matrix 27 of this first device 21 and - another second annular heat exchange device 30' which extends around the axis X and is located in the vein V2, this second device 30' comprising a heat exchange matrix 31' which are axially spaced from the heat exchange matrix 26' of the first device 21' and which are interposed between the cover 27' of the first device 21' and another cover 32' of the second device 30, the cover 27' of the first device 21' having a diameter D2' predetermined measured at the axial center of the heat exchange matrix 31' of the second device 30'.

[0140] It can be seen in Figure 10 that the heat exchange matrices 27', 31' of the devices 21', 30' are spaced axially from each other in the vein V2, by an axial distance noted L'. In the example shown, the device 21' located on the internal wall 23 is located downstream of the device 30'.

[0141] In this embodiment, D2' is less than D1', that is to say that an internal peripheral part of the heat exchange matrix 31' of the second device 30' is aligned in the axial direction with an external peripheral part of the heat exchange matrix 26' of the first device 21'.

[0142] These devices 21', 30' are preferably of the air-oil type and each comprise an oil circuit 28' in addition to the heat exchange matrix 26', 31' which is located in the vein V2 and configured to be swept by the gas flow F2, as mentioned above.

[0143] Devices 21', 30' have the 27' cover in common.

[0144] The heat exchange matrix 26' of the device 21' is covered by the annular cover 27' which extends axially, here upstream, to form an external cover of the heat exchange matrix 31' of the device 30'. This cover 27' is thus located at the external periphery of the heat exchange matrix 26' of the device 21' and at the internal periphery of the heat exchange matrix 31' of the device 30'. The heat exchange matrix 31' of the device 30' is further connected to the other cover 32' which is therefore located at the external periphery of these surface exchangers 31'.

[0145] The cover 27' of the first device 21' comprises several successive axial sections along the axis, namely: - an upstream end section 27a' which is located upstream of the heat exchange matrix 31' of the second device 30',

[0146] - a section 27b' which extends to the internal periphery of the heat exchange matrix 31' of the second device 30',

[0147] - an intermediate section 27c' which extends axially between the heat exchange matrix 31' of the second device 30' and the heat exchange matrix 26' of the first device 21',

[0148] - a section 27d' which extends to the external periphery of the heat exchange matrix 26' of the first device 21', and

[0149] - a downstream end section 27 e ' which is located downstream of the heat exchange matrix 26' of the first device 21'.

[0150] The 32' cover of the second 30' device comprises:

[0151] - an upstream end section 32a' located upstream of the heat exchange matrix 31' of this second device 30',

[0152] - a section located at the external periphery of the heat exchange matrix 31' of this second device 30', and

[0153] - a downstream end section 32c' located downstream of the heat exchange matrix 31' of this second device 30'.

[0154] It can be seen that each of the upstream end sections 27a', 32a' forms a divergent, and that each of the downstream end sections 27e', 32c' forms a convergent.

[0155] In the example shown, the end sections 27a', 27e', 32a', 32c' each have a curved shape.

[0156] The cover 32' of the second device 30' has a predetermined diameter D3' measured at the axial center of the heat exchange matrix 31' of the second device 30'. In the example shown, D3' is greater than DT.

[0157] In Figure 8:

[0158] - HT represents the diameter at the free upstream end of the cover 32' or of the upstream end section 32a' of this cover 32',

[0159] - H2' represents the diameter at the downstream end of the upstream end section 32a' of this cover 32',

[0160] - H3' represents the diameter at the upstream end of the downstream end section 32c' of this hood 32', - H4' represents the diameter at the free downstream end of the hood 32' or of the downstream end section 32c' of this hood 32't,

[0161] - H5' represents the diameter at the free upstream end of the cover 27' or of the upstream end section 27a' of this cover 27',

[0162] - H6' represents the diameter at the downstream end of the upstream end section 27a' of this cover 27',

[0163] - H7' represents the diameter at the upstream end of the intermediate section 27c',

[0164] - H8' represents the diameter at the downstream end of the intermediate section 27c',

[0165] - H9' represents the diameter at the upstream end of the downstream end section 27e' of this hood 27', and

[0166] - H10' represents the diameter at the free downstream end of the hood or of the downstream end section 27e' of this hood 27'.

[0167] These diameters are measured relative to the X axis.

[0168] In the example shown:

[0169] - HT is less than or equal to H2', H3 and H4' in particular,

[0170] - H5' is lower than H2', H3' and H6' in particular,

[0171] - H7' is lower than H8', H3' and H4' in particular,

[0172] - H2' and H3' are greater than H8' and H9'.

[0173] Each of the 2T, 30' devices may comprise a single heat exchanger, or be sectorized and comprise two or more heat exchangers distributed around the X axis, as discussed above.

[0174] In the example shown, the 2T device located on the right in the drawing occupies a height hT in the vein of between 20 and 50% of the height hvT of this vein. The 30' device located on the left in the drawing occupies a height h2' in the vein of between 10 and 30% of the height hv2'.

[0175] The heat exchange matrix 26' of the first 2T device has a height h3' or radial dimension greater than or equal to that h4 ! of the heat exchange matrix 3T of the second device 30. The sum of the heights h3, h4 or radial dimensions of the heat exchange matrix 26', 3T of the first and second devices 2T, 30' is less than the height hv1, hv2 or radial dimension of the vein V2 measured at the level of these devices 2T, 30'.

[0176] Alternatively, the heat exchange system 20 could comprise devices 2T, 30' only on the side of the internal wall 23. It is understood that an external peripheral part of the air flow F2 flowing in the vein will be used in the devices 21, 30, as mentioned above. Among the rest of the air flow, an internal peripheral part will be used in the devices 21', 30', and will be divided into a first part, external peripheral, which will enter the device 30', and the rest, the internal peripheral part, which will enter the device 21'.

[0177] The fourth embodiment illustrated in Figure 11 differs from the second embodiment in particular in that the heat exchange system 20 comprises a third annular heat exchange device 40 which extends around the axis X and is located in the vein V2.

[0178] The system thus includes:

[0179] The third device 40 comprises a heat exchange matrix 41 which is axially spaced from the heat exchange matrices 26, 31 of the devices 21, 30 and which is interposed between the cover 32 of the second device 31 and another cover 42 of the third device 40.

[0180] The cover 32 of the second device has a predetermined diameter D3 measured at the axial center of the heat exchange matrix 31 of the second device 30, and a predetermined diameter D4 measured at the axial center of the heat exchange matrix 41 of the third device 40.

[0181] In the example shown, D4 is greater than D3.

[0182] The upstream end section 32a of the cover 32 of the second device 30 is broken down into more portions including:

[0183] - an upstream portion 32a1 located upstream of the heat exchange matrix 41 of the third device 40,

[0184] - an intermediate portion 32a2 located at the external periphery of the heat exchange matrix 41 of this third device 40, and

[0185] - a downstream portion 32a3 located downstream of the heat exchange matrix 41 of this third device 40.

[0186] The cover 42 of the third device 40 comprises:

[0187] - an upstream end section 42a located upstream of the heat exchange matrix 41 of this third device 40, - a section 42b located at the internal periphery of the heat exchange matrix 41 of this third device 40, and

[0188] - a downstream end section 42c located downstream of the heat exchange matrix 41 of this third device 40.

[0189] It can be seen that the upstream end sections and portions 27a, 32a1, 42a form a divergent point, and that the downstream end sections 27e, 32c, 42c form a convergent point. In the example shown, the end sections and portions 27a, 32a1, 42a, 27e, 32c, 42c each have a curved shape.

[0190] The cover 42 of the third device 40 has a predetermined diameter D5 measured at the axial center of the heat exchange matrix of the third device. In the example shown, D5 is greater than or equal to D1 and D3.

[0191] In Figure 11:

[0192] - H11 represents the diameter at the free upstream end of the cover 42 or of the upstream end section 42a of this cover 42,

[0193] - H12 represents the diameter at the downstream end of the upstream end section 42a of this cover 42,

[0194] - H13 represents the diameter at the upstream end of the downstream end section 42c of this cover 42,

[0195] - H14 represents the diameter at the free downstream end of the cover 42 or of the downstream end section 42c of this cover 42.

[0196] These diameters are measured relative to the X axis.

[0197] In the example shown:

[0198] - H11 is greater than or equal to H12, H1 and H5 in particular, and could be the maximum diameter of the 20 system.

[0199] Each of the devices 21, 30 may comprise a single heat exchanger, or be sectorized and comprise two or more heat exchangers distributed around the X axis, as discussed above.

[0200] The heat exchange matrix 41 of the third device 40 has a height h5 or radial dimension less than or equal to that h4 of the heat exchange matrix 31 of the second device 30. The sum of the heights h3, h4, h5 or radial dimensions of the heat exchange matrices 26, 31, 41 of the devices 21, 30, 40 is less than or equal to the height hv1, hv2, hv3 or radial dimension of the vein measured at these devices 21, 30, 40. It is understood that an external peripheral part of the air flow F2 flowing in the vein will be used in the devices 21, 30, 40 and that the rest of this flow will bypass the devices 21, 30, 40. The air used in the devices will be divided into a first, internal peripheral part, which will penetrate into the device 40, a middle part which will penetrate into the device 30, and the remainder, the external peripheral part, which will penetrate into the device 21.

[0201] The fifth embodiment of Figure 12 differs from the embodiment of Figure 1 in particular in that the second device 30 is located downstream and not upstream of the first device 21.

[0202] The heat exchange matrix 26 of the device 21 is covered by the annular cover 27 which extends axially, here downstream, to form an external cover of the heat exchange matrix 31 of the device 30. This cover 27 is thus located at the internal periphery of the heat exchange matrix 26 of the device 21 and at the external periphery of the heat exchange matrix 31 of the device 30. The heat exchange matrix 31 of the device 30 is further connected to the other cover 32 which is therefore located at the internal periphery of this heat exchange matrix 31.

[0203] The cover 27 of the first device 21 comprises several successive axial sections along the X axis, namely:

[0204] - an upstream end section 27a which is located upstream of the heat exchange matrix 26 of the first device 21,

[0205] - a section 27b which extends to the internal periphery of the heat exchange matrix 26 of the first device 21,

[0206] - an intermediate section 27c which extends axially between the heat exchange matrix 26 of the first device 21 and the heat exchange matrix 31 of the second device 32,

[0207] - a section 27d which extends to the external periphery of the heat exchange matrix 31 of the second device 30, and

[0208] - a downstream end section 27e which is located downstream of the heat exchange matrix 31 of the second device 30.

[0209] The cover 32 of the second device 30 comprises:

[0210] - an upstream end section 32a located upstream of the heat exchange matrix 31 of this second device 30, - a section 32b located at the internal periphery of the heat exchange matrix 31 of this second device 30, and

[0211] - a downstream end section 32c located downstream of the heat exchange matrix 31 of this second device 30.

[0212] It can be seen that each of the upstream end sections 27a, 32a forms a divergent, and that each of the downstream end sections 27e, 32c forms a convergent.

[0213] In the example shown, the end sections 27a, 27e, 32a, 32c each have a truncated cone shape.

[0214] In the example shown, D3 is less than D1 . D2 is greater than D1 .

[0215] In Figure 12:

[0216] - H1 represents the diameter at the free upstream end of the cover 32 or of the upstream end section 32a of this cover 32,

[0217] - H2 represents the diameter at the downstream end of the upstream end section 32a of this cover 32,

[0218] - H3 represents the diameter at the upstream end of the downstream end section 32c of this cover 32,

[0219] - H4 represents the diameter at the free downstream end of the cover 32 or of the downstream end section 32c of this cover 32,

[0220] - H5 represents the diameter at the free upstream end of the cover 27 or of the upstream end section 27a of this cover 27,

[0221] - H6 represents the diameter at the downstream end of the upstream end section 27a of this cover 27,

[0222] - H7 represents the diameter at the upstream end of the intermediate section 27c,

[0223] - H8 represents the diameter at the downstream end of the intermediate section 27c,

[0224] - H9 represents the diameter at the upstream end of the downstream end section 27e of this cover 27, and

[0225] - H10 represents the diameter at the free downstream end of the cover 27 or of the downstream end section 27e of this cover 27.

[0226] These diameters are measured relative to the X axis.

[0227] In the example shown:

[0228] - H1 is greater than or equal to H2, but less than H5 and H6 in particular,

[0229] - H5 could be the maximum diameter of the 20 system, - H7 is less than H8, H9 and H10 in particular

[0230] - H2 and H3 are lower than H8 and H9.

[0231] Each of the devices 21, 30 may comprise a single heat exchanger, or be sectorized and comprise two or more heat exchangers distributed around the X axis, as discussed above.

[0232] In the example shown, the device 21 located on the left in the drawing occupies a height h1 in the vein of between 20 and 50% of the height hv1 of this vein. The device 30 located on the right in the drawing occupies a height h2 in the vein of between 10 and 30% of the height hv2.

[0233] The heat exchange matrix 26 of the first device 21 has a height h3 or radial dimension greater than or equal to that h4 of the heat exchange matrix 31 of the second device 30. The sum of the heights h3, h4 or radial dimensions of the heat exchange matrices 26, 31 of the first and second devices 21, 30 is less than the height hv1, hv2 or radial dimension of the vein V2 measured at the level of these devices 21, 30.

[0234] It is understood that an external peripheral part of the air flow F2 flowing in the vein will be used in the device 21 and that the rest of this flow will bypass this device 21. Among this air flow which bypasses the device 21, an external peripheral part will be taken and will enter the device 30, and the rest will bypass this device 30.

[0235] The sixth embodiment of Figure 13 differs from the embodiment of Figure 12 essentially in that the covers 27, 32 are curved.

[0236] The operation of the system in Figure 13 is similar to that in Figure 12.

[0237] The embodiment of Figure 14 is similar to that of Figure 10 except that the second devices 30, 30' are arranged downstream of the first devices 21, 21' and are therefore of the type described with reference to Figures 12 and 13.

[0238] It is understood that an external peripheral portion of the air flow F2 flowing in the vein will be used in the devices 21, 30, as mentioned above. Among the rest of the air flow, an internal peripheral portion will be used in the devices 21', 30', and will be divided into a first, internal peripheral portion, which will enter the device 21 and another internal peripheral portion of the air flow which bypasses the device 21', which will enter the device 30'.

[0239] In the embodiment of Figure 15, the devices 21 and 30 are respectively carried by the external 22 and internal 23 walls.

[0240] The first device 21 is similar to that described above in relation to figures 1 and 2 for example.

[0241] The second device 30 is here located upstream of the first device 21 and comprises a heat exchange matrix 31 which is axially spaced from the heat exchange matrix 26 of the first device 21 and which is interposed between the cover 27 of the first device 21 and the wall 23.

[0242] It is therefore understood that the devices 21, 30 share the same cover 27 and that there are no other covers in the system 20 insofar as the heat exchange matrix 26 of the first device 21 extends between the cover 27 and the external wall 22, and the heat exchange matrix 31 of the second device 30 extends between the cover 27 and the internal wall 23.

[0243] Hood 27 includes:

[0244] - an upstream end section 27a which is located upstream of the heat exchange matrix 31 of the second device 30 and which forms a divergent,

[0245] - a section 27b which extends to the external periphery of the heat exchange matrix 31 of the second device 30,

[0246] - an intermediate section 27c which extends axially between the heat exchange matrix 31 of the second device 30 and the heat exchange matrix 26 of the first device 21,

[0247] - a section 27d which extends to the internal periphery of the heat exchange matrix 26 of the first device 21, and

[0248] - a downstream end section 27e which forms a convergent and which is located downstream of the heat exchange matrix 26 of the first device 21.

[0249] In Figure 15:

[0250] - H5” represents the diameter at the free upstream end of the cover 27 or of the upstream end section 27a of this cover 27,

[0251] - H6” represents the diameter at the downstream end of the upstream end section 27a of this cover 27, - H7” represents the diameter at the upstream end of the intermediate section 27c,

[0252] - H8” represents the diameter at the downstream end of the intermediate section 27c,

[0253] - H9” represents the diameter at the upstream end of the downstream end section 27e of this cover 27, and

[0254] - H10” represents the diameter at the free downstream end of the cover 27 or of the downstream end section 27e of this cover 27.

[0255] These diameters are measured relative to the X axis.

[0256] In the example shown:

[0257] - H5” is greater than H6” in particular,

[0258] - H7” is superior to H8 in particular.

[0259] Each of the devices 21, 30 may comprise a single heat exchanger, or be sectorized and comprise two or more heat exchangers distributed around the X axis, as discussed above.

[0260] In the example shown, the device 21 located on the right in the drawing occupies a height h1 in the vein of between 50 and 80% of the height hv1 of this vein. The device 30 located on the left in the drawing occupies a height h2 in the vein of between 50 and 80% of the height hv2.

[0261] The heat exchange matrix 26 of the first device 21 has a height h2 or radial dimension greater than or equal to that h4 of the heat exchange matrix 32 of the second device 30. The sum of the heights h2, h4 or radial dimensions of the heat exchange matrices 26, 31 of the first and second devices 21, 30 is greater than the height hv1, hv2 or radial dimension of the vein measured at the level of these devices 21, 30.

[0262] It is understood that an internal peripheral part of the air flow F2 flowing in the vein will penetrate into the device 30 while the rest of the air flow will penetrate into the device 21. The entire air flow is therefore used to participate in the exchange of calories.

[0263] Installing these devices partially overlapped with an axial offset limits both the axial and radial space occupied by the devices. Limiting the radial space allows for higher slowdown ratios within each of the devices.

Claims

CLAIMS 1. Turbomachine for an aircraft, comprising a heat exchange system (20), this system comprising: - two annular walls, respectively external (22) and internal (23), which extend around each other and around the same axis (X), and which are configured to define between them a flow vein (V2) of a gas flow (F2), - a first annular heat exchange device (21) which extends around the axis (X) and is carried by one of said walls (22, 23), and which is located in the vein (V2), this first device (21) comprising a heat exchange matrix (26) interposed between this wall (22) and a cover (27) which has a predetermined diameter D1 measured at the axial middle of the heat exchange matrix (26) of the first device (21), characterized in that it further comprises: - a second annular heat exchange device (30) which extends around the axis (X) and is located in the vein (V2), this second device (30) comprising a heat exchange matrix (31) which is axially spaced from the heat exchange matrix (26) of the first device (21) and which is interposed between the cover (27) of the first device (21) and the opposite wall (23) or another cover (32) of the second device (30), the cover (27) of the first device (21) having a predetermined diameter D2 measured at the axial center of the heat exchange matrix (31) of the second device (30), and in that: - D2 is greater than D1 when the first device (21) is carried by the external wall (22), or - D2 is less than D1 when the first device (21) is carried by the internal wall (23), 2. Turbomachine according to claim 1, characterized in that the cover (27) of the first device (21) comprises several successive axial sections along the axis (X): - an upstream end section (27a) which is located upstream of the heat exchange matrix (31) of the second device (30), a section (27b) which extends at the periphery of the heat exchange matrix (31) of the second device (30), an intermediate section (27c) which extends axially between the heat exchange matrix (31) of the second device (30) and the heat exchange matrix (26) of the first device (31), a section (27d) which extends at the periphery of the heat exchange matrix (26) of the first device (21), and a downstream end section (27e) which is located downstream of the heat exchange matrix (26) of the first device (21), or - an upstream end section (27a) which extends upstream of the heat exchange matrix (26) of the first device (21), a section (27b) which extends at the periphery of the heat exchange matrix (26) of the first device (21), an intermediate section (27c) which extends axially between the heat exchange matrix (26) of the first device (21) and the heat exchange matrix (31) of the second device (30), a section (27d) which extends at the periphery of the heat exchange matrix (31) of the second device (30), and a downstream end section (27e) which is located downstream of the heat exchange matrix (31) of the second device (30).

3. Turbomachine according to claim 2, characterized in that the second device (30) comprises said other cover (32) which comprises an upstream end section (32a) located upstream of the heat exchange matrix (31) of this second device (30), a section (32b) located at the periphery of the heat exchange matrix (31) of this second device (30), and a downstream end section (32c) located downstream of the heat exchange matrix (31) of this second device (30).

4. Turbomachine according to one of the preceding claims, characterized in that the second device (30) comprises said other cover (32) which has a predetermined diameter D3 measured at the axial center of the heat exchange matrix (31) of the second device (30), and in that: - D3 is greater than D1 when the first device (21) is carried by the external wall (22), or - D3 is less than D1 when the first device (21) is carried by the internal wall (23).

5. Turbomachine according to one of the preceding claims, characterized in that it further comprises: - a third annular heat exchange device (40) of the surface type which extends around the axis (X) and is located in the vein (V2), this third device (40) comprising a heat exchange matrix (41) which is axially spaced from the heat exchange matrix (26, 31) of the first and second devices (21, 30) and which is interposed between the cover (32) of the second device (30) and the other of the walls (22) or another cover (42) of the third device (40), the second device (30) comprising said other cover (32) which has a predetermined diameter D3 measured at the axial middle of the heat exchange matrix (31) of the second device (30), and a predetermined diameter D4 measured at the axial middle of the heat exchange matrix (41) of the third device (40), and in that: - D4 is greater than D3 when the first device (21) is carried by the external wall (23), or - D4 is less than D3 when the first device (21) is carried by the internal wall (22).

6. Turbomachine according to claim 5, characterized in that the third device (40) comprises said other cover (42) which comprises an upstream end section (42a) located upstream of the heat exchange matrix (41) of this third device (40), a section (42b) located at the periphery of the heat exchange matrix (41) of this third device (40), and a downstream end section (42c) located downstream of the heat exchange matrix (41) of this third device (40).

7. Turbomachine according to claim 2, 3 or 6, characterized in that the or each upstream end section (27a, 32a, 42a) forms a divergent, and the or each downstream end section (27e, 32c, 42c) forms a convergent.

8. Turbomachine according to claim 2, 3, 6 or 7, characterized in that the end sections (27a, 27e, 32a, 32c, 42a, 42c) have a truncated or rounded shape.

9. Turbomachine according to one of the preceding claims, characterized in that the heat exchange matrix (26) of the first device (21) has a height (h3) or radial dimension greater than or equal to that (h4) of the heat exchange matrix (31) of the second device (30).

10. Turbomachine according to one of claims 1 to 9, characterized in that the sum of the heights (h3, h4) or radial dimensions of the heat exchange matrix (26, 31) of the first and second devices (21, 30) is less than the height (hv1, hv2) or radial dimension of the vein (V2) measured at the level of these devices (21, 30).

11. Turbomachine according to one of claims 1 to 9, characterized in that the sum of the heights (h3, h4) or radial dimensions of the heat exchange matrix (26, 31) of the first and second devices (21, 30) is greater than the height (hv1, hv2) or radial dimension of the vein measured at the level of these devices (21, 30).

12. Turbomachine according to any one of the preceding claims, characterized in that each of the external and internal walls (22, 23) carries said first heat exchange device (21), which is associated with said second heat exchange device (30) or even with said third heat exchange device (30).

Images