Heat exchange system for aircraft turbine engine

Abstract

The present application relates to a heat exchange system (20), in particular for an aircraft turbine engine (1), comprising: two annular walls, respectively an outer wall (22) and an inner wall (23); -a first annular heat exchange device (21) carried by one of said walls (22) and comprising a heat exchange matrix (26) interposed between the wall (22) and the fairing (27), characterized in that the heat exchange system further comprises:-a second annular heat exchange device (30) comprising a heat exchange matrix (31) carried by one of said walls (22) and comprising a heat exchange matrix (32) interposed between the wall (22) and the fairing (27); the heat exchange substrate is axially spaced from the heat exchange substrate (26) of the first device (21) and is interposed between the fairing (27) of the first device (21) and the opposite wall (23) or another fairing (32) of the second device (30).

Description

Technical Field

[0001] The present invention generally relates to the field of cooling and has particular application in the field of aviation. The present invention is directed in particular to a heat exchange system, in particular for a turbine engine, in particular for aircraft. Background Art

[0002] The prior art includes, inter alia, the following documents: US-B1-6,668,915, EP-A1-3,196,443 and WO-A1-2022 / 064136.

[0003] Turbine engines, in particular for aircraft, include various components and / or devices that require lubrication and / or cooling, such as rolling bearings and gears. Depending on the power of the components and / or devices, the heat released by these components can be quite high, which is transported via a fluid and discharged towards an available cooling source in the aircraft.

[0004] It is known to equip turbine engines with one or more heat exchange systems for exchanging heat between a fluid (usually oil) and a cooling source (air, fuel, etc.). There are even different types of heat exchange systems, such as fuel / oil heat exchangers, often referred to by the acronym FCOC (Fuel Cooled Oil Cooler), and air / oil heat exchangers, referred to by the acronym ACOC (Air-Cooled Oil Cooler).

[0005] The FCOC heat exchanger has a dual function: heating the fuel before combustion in the turbine engine's combustion chamber and cooling the oil heated by the turbine engine's radiated heat. However, the FCOC heat exchanger is not sufficient to absorb all the radiated heat because the temperature of the fuel is limited for safety reasons.

[0006] Additional cooling is achieved by means of ACOC heat exchangers, in particular surface heat exchangers denoted by the acronym SACOC. Surface heat exchangers are typically arranged in the secondary ducts of a turbine engine and use the secondary air flow to cool the oil circulating in the turbine engine. These heat exchangers are in the form of metal surface components that allow the oil to pass through machined channels. The secondary air flow is guided along a heat exchange matrix carried by the surface component, the purpose of which is to increase the contact surface with the secondary air flow and absorb heat. However, a disadvantage of SACOC heat exchangers is that they cause additional pressure losses in the associated secondary ducts because they disrupt the air flow, which has an impact on the performance and specific fuel consumption of the turbine engine.

[0007] The applicant has proposed a solution to this problem in documents FR-A1-3096409 and FR-A1-3096444.

[0008] Furthermore, due to the need for higher speed and power requirements to meet specification trends on turbine engines, cooling requirements for the lubrication fluid are increasing.

[0009] In fact, ACOC heat exchangers are increasingly used in next generation engines due to the significant increase in dissipated heat, mainly due to:

[0010] - Future engines will be larger, which increases the demand for lubrication and oil cooling,

[0011] - the presence of reduction gears in new motor architectures, which transmit very high mechanical power and require oil lubrication and cooling, and

[0012] -Adding electric motors to the engine to achieve hybrid power requires oil lubrication and cooling.

[0013] An engine may include multiple oil circuits, each with a specific function, such as a first circuit for cooling oil used exclusively for lubricating and cooling the engine, a second circuit for lubricating and cooling the motor reduction gears, a third circuit for cooling the electric motor, and so on. Temperature and oil flow rates must be controlled according to the respective circuits. For example, the temperature range of the oil used to lubricate and cool the electric motor differs from that of the oil used to cool the engine. Therefore, the ACOC is preferably divided into several exchangers, each dedicated to a specific oil circuit. These various heat exchangers are typically distributed around the longitudinal axis of the engine.

[0014] The increasing demand for cooling has a direct impact on the size of the ACOC. Therefore, a large exchanger is desirable to remove a significant amount of oil heat. To remove oil heat, the ACOC may occupy all available space in the duct and therefore extend around the duct and across its entire height or radial dimension to achieve the necessary air flow rate to remove the significant amount of heat at the sizing point, which typically occurs during takeoff in extremely hot weather.

[0015] However, the fact that the ACOC exchanger occupies the entire radial height of the duct does not make it possible to use the solutions described in documents FR-A1-3 096 409 and FR-A1-3 096 444 to control the flow through the exchanger.

[0016] As a result, all airflow passes through the ACOCs, and each ACOC operates at suboptimal aerodynamic thermal performance. This causes a high pressure drop on the air side, resulting in inefficient heat exchangers.

[0017] The object of the present invention is to propose an improvement over the prior art, optimizing the efficiency of the heat exchange while avoiding pressure losses and disturbing the air flow as little as possible. Summary of the Invention

[0018] Therefore, the present invention proposes a heat exchange system, in particular a heat exchange system for an aircraft turbine engine, comprising:

[0019] two annular walls, respectively an outer wall and an inner wall, extending around one another and around the same axis and configured to define between them a flow duct for the air flow,

[0020] a first annular heat exchange device extending around the axis and carried by one of the walls and located in the duct, the first device comprising a heat exchange matrix inserted between the wall and a fairing having a predetermined diameter D1 measured at the axial center of the heat exchange matrix of the first device,

[0021] Characterized in that, the heat exchange system further comprises:

[0022] a second annular heat exchange device extending about the axis and located in the duct, the second device comprising a heat exchange matrix axially spaced from the heat exchange matrix of the first device and interposed between a fairing of the first device and an opposite wall or another fairing of the second device, the fairing of the first device having a predetermined diameter D2 measured at the axial center of the heat exchange matrix of the second device,

[0023] And among them:

[0024] - when the first means is carried by the outer wall, D2 is greater than D1, or

[0025] - When the first means is carried by the inner wall, D2 is smaller than D1.

[0026] The invention therefore proposes combining at least two heat exchange devices in a duct and positioning these devices so that they are on the one hand axially offset from one another and on the other hand staggered relative to one another.

[0027] The axial offset of the devices is due to the heat exchange matrices of the devices being axially spaced apart from each other.The heat exchange matrix of a first device is located upstream or downstream relative to the heat exchange matrix of a second device.

[0028] In the present application, the expressions upstream and downstream refer to the flow of air or gas in the duct during normal operation of the turbine engine.

[0029] In the present application, a heat exchange matrix may include fins and / or plate portions and / or tube portions. The matrix may be layered, for example, comprising a stack of multiple layers, each layer including a fin, at least one plate portion, or at least one tube portion. The fins are designed to be swept by airflow, and the plate portions or tube portions are, for example, traversed by or include an oil circuit.

[0030] The staggering of the devices is due to the devices sharing a common fairing, which is 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.Thus, in addition to being staggered, the devices may also overlap axially.

[0031] The heat exchange system may include one or more of the following features, which may be considered independently or in combination:

[0032] The fairing of the first device comprises a plurality of successive axial sections along the axis:

[0033] an upstream end section situated upstream of the heat exchange matrix of the second device; a section extending at the periphery of the heat exchange matrix of the second device; an intermediate section extending axially between the heat exchange matrix of the second device and the heat exchange matrix of the first device; a section extending at the periphery of the heat exchange matrix of the first device; and a downstream end section situated downstream of the heat exchange matrix of the first device, or

[0034] an upstream end section extending upstream of the heat exchange matrix of the first device; a section extending at the periphery of the heat exchange matrix of the first device; an intermediate section extending axially between the heat exchange matrix of the first device and the heat exchange matrix of the second device; a section extending at the periphery of the heat exchange matrix of the second device; and a downstream end section located downstream of the heat exchange matrix of the second device;

[0035] the fairing of the second device comprises an upstream end section located upstream of the heat exchange matrix of the second device, a section located at the periphery of the heat exchange matrix of the second device, and a downstream end section located downstream of the heat exchange matrix of the second device;

[0036] - the fairing of the second device has a predetermined diameter D3 measured at the axial center of the heat exchange matrix of the second device, and wherein D3 is smaller or larger than D1;

[0037] - D3 is greater than D1 when the first means is carried by the outer wall, or D3 is less than D1 when the first means is carried by the inner wall;

[0038] This emphasizes the staggering of the devices and the axial alignment of the heat exchange matrices of the devices; the fairing of the second device has a free upstream end located upstream of the free upstream end of the fairing of the first device or between the upstream and downstream ends of the intermediate section;

[0039] - The system further comprises:

[0040] a third annular heat exchange device extending about the axis and located in the duct, the third device comprising a heat exchange matrix axially spaced apart from the heat exchange matrices of the first and second devices and interposed between a fairing of the second device and another of the walls or another fairing of the third device, the fairing of the second device having a predetermined diameter D3 measured at the axial center of the heat exchange matrix of the second device and a predetermined diameter D4 measured at the axial center of the heat exchange matrix of the third device,

[0041] and

[0042] - when the first means is carried by the outer wall, D4 is greater than D3, or

[0043] - when the first device is carried by the inner wall, D4 is smaller than D3;

[0044] the fairing of the third device comprises an upstream end section located upstream of the heat exchange matrix of the third device, a section located at the periphery of the heat exchange matrix of the third device, and a downstream end section located downstream of the heat exchange matrix of the third device;

[0045] - the or each upstream end section forms a diverging portion and the or each downstream end section forms a converging portion;

[0046] - the end section has a frustoconical or circular shape;

[0047] - the height or radial dimension of the heat exchange matrix of the first device is greater than or equal to the height or radial dimension of the heat exchange matrix of the second device;

[0048] the sum of the heights or radial dimensions of the heat exchange substrates of the first and second devices is less than the heights or radial dimensions of the ducts measured at these devices;

[0049] the sum of the heights or radial dimensions of the heat exchange substrates of the first and second devices is greater than the heights or radial dimensions of the ducts measured at these devices;

[0050] - each of the outer and inner walls carries a first means of the above-mentioned type associated with a second means of the above-mentioned type or even a third means of the above-mentioned type;

[0051] -- Each unit in the installation is of ACOC or SACOC type;

[0052] Each diverging portion and each converging portion has a frustoconical or rounded shape; the rounded shape improves the aerodynamics of the flow around the device, thereby reducing the pressure drop caused by installing the assembly. These shapes can be obtained, for example, by additive manufacturing;

[0053] - the or each fairing being independent of the walls of the duct and therefore not connected to those walls;

[0054] - the first heat exchange device is a surface heat exchange device, and / or the second heat exchange device is a surface heat exchange device, and / or the third heat exchange device is a surface heat exchange device;

[0055] - the or each heat exchange device is a SACOC or ACOC type heat exchange device;

[0056] The or each fairing is at a distance from the wall of the duct so that a portion of the airflow flowing in the duct can bypass the or each heat exchange device.

[0057] The present invention also relates to a turbine engine or electronic equipment comprising at least one heat exchange system as described above. The present invention can be used for cooling equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The invention will be better understood and further objects, details, features and advantages of the invention will become clearer from the following detailed explanatory description of an embodiment of the invention given as a purely illustrative and non-limiting example with reference to the accompanying schematic drawings, in which:

[0059] [ Figure 1 ] Figure 1 is a schematic half view of an axial section of an example of a turbine engine to which the present invention is applied;

[0060] [ Figure 2 ] Figure 2 is a schematic cross-sectional view of a heat exchange system;

[0061] [ Figure 3 ] Figure 3 Shown Figure 2 a schematic axial cross section of the system shown;

[0062] [ Figure 4 ] Figure 4 For Figure 3 Another schematic diagram of a system similar to the one shown;

[0063] [ Figure 5 ] Figure 5is a partial schematic perspective view of a heat exchange device;

[0064] [Figures 6a-6b] Figures 6a and 6b are schematic cross-sectional views of heat exchange systems, each of which includes a segmented heat exchange device;

[0065] [ Figure 7 ] Figure 7 is a schematic axial cross-sectional view of the system in FIG6 a;

[0066] [ Figure 8 ] Figure 8 is a schematic axial cross-sectional view of a heat exchange system according to a first embodiment of the present invention;

[0067] [ Figure 9 ] Figure 9 is a schematic axial cross-sectional view of a heat exchange system according to a second embodiment of the present invention;

[0068] [ Figure 10 ] Figure 10 is a schematic axial cross-sectional view of a heat exchange system according to a third embodiment of the present invention;

[0069] [ Figure 11 ] Figure 11 is a schematic axial cross-sectional view of a heat exchange system according to a fourth embodiment of the present invention;

[0070] [ Figure 12 ] Figure 12 is a schematic axial cross-sectional view of a heat exchange system according to a fifth embodiment of the present invention;

[0071] [ Figure 13 ] Figure 13 is a schematic axial cross-sectional view of a heat exchange system according to a sixth embodiment of the present invention;

[0072] [ Figure 14 ] Figure 14 is a schematic axial cross-sectional view of a heat exchange system according to a seventh embodiment of the present invention;

[0073] [ Figure 15 ] Figure 15 is a schematic axial cross-sectional view of a heat exchange system according to an eighth embodiment of the present invention. DETAILED DESCRIPTION

[0074] Figure 1 Shown is an axial cross section of a turbine engine to which the invention applies, having a longitudinal axis X. The turbine engine shown is a turbofan engine 1 designed to be installed on an aircraft. Of course, the invention is not limited to this type of turbine engine.

[0075] The twin-flow turbine engine 1 generally comprises a gas generator 2 , with a fan or a fan module 3 installed upstream of the gas generator 2 .

[0076] In the present invention, the terms “upstream” and “downstream” are defined relative to the gas flow in the turbine engine 1 and here along the longitudinal axis X.

[0077] 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).

[0078] Typically, the turbine engine 1 includes a low-pressure shaft 7 and a high-pressure shaft 8 . The low-pressure shaft connects the low-pressure compressor 4 a and the low-pressure turbine 6 a to form a low-pressure body. The high-pressure shaft connects the high-pressure compressor 4 b and the high-pressure turbine 6 b to form a high-pressure body.

[0079] The low-pressure shaft 7, centered on the longitudinal axis X, drives the fan shaft 9 via a reduction gear 10. A rotary guide bearing 15 also guides the low-pressure shaft 7 in rotation relative to the fixed structure or stator of the turbine engine. The high-pressure shaft 8 is also guided in rotation by a guide bearing (not shown).

[0080] The fan 3 is located in a duct in a fan housing 11 carried by the nacelle 12 and generates a primary air flow F1 that circulates through the gas generator 2 in a primary duct V1 and a secondary air flow F2 that circulates around the gas generator 2 in a secondary duct V2 .

[0081] The secondary air flow F2 is injected by a secondary nozzle 13 at the end of the nacelle, while the primary air flow F1 is injected to the outside of the turbine engine 1 via an injection nozzle 14 located downstream of the gas generator 2 .

[0082] In the following description, the fan case 11 and the nacelle 12 are considered to be a single piece.

[0083] In this exemplary configuration of turbine engine 1, guide bearing 15 and reduction gear 10 must be lubricated and / or cooled to ensure the performance of turbine engine 1. The energy generated thereby is dissipated into a fluid from a fluid supply source installed in turbine engine 1, which is used to lubricate and / or cool various components and / or equipment in turbine engine 1. Of course, other equipment in turbine engine 1 generates a significant amount of heat, which needs to be extracted from its environment.

[0084] To this end, the turbine engine 1 comprises a heat exchange system 20 which enables the fluid configured to lubricate and / or cool these components and / or devices to be cooled. In this example, the fluid is oil, and the cold source for cooling the oil is the air flow circulating in the turbine engine, in particular the secondary air flow F2.

[0085] In the context of the present invention, the heat exchange system 20 refers to a system comprising the following components:

[0086] two annular walls, one outer wall and one inner wall respectively, extending around each other and around the same axis and configured to define between them a flow duct for the air flow, and

[0087] - At least one annular heat exchange device located in the duct.

[0088] exist Figure 1 For example, the heat exchange system 20 of the turbine engine 1 includes: an outer wall 22 formed by the fan casing 11 and / or the nacelle 12, an inner wall 23 formed by the casing of the gas generator 2, and a heat exchange device 21 supported by the outer wall 22 and located in the duct V2.

[0089] The heat exchange device 21 is, for example, a surface type (eg, SACOC type) heat exchange device, preferably an air / oil type heat exchange device.

[0090] Device 21 includes an oil circuit and a heat exchange matrix located in duct V2 and configured to be swept by airflow F2. As described above, the heat exchange matrix may include fins and / or plate portions and / or tube portions. The matrix may be staggered and, for example, comprise a stack of multiple layers, each layer including fins, at least one plate portion, or at least one tube portion. The fins are designed to be swept by the airflow, and the plate portions or tube portions, for example, are passed through by the oil circuit or include such an oil circuit.

[0091] Figure 2 and Figure 3 This type of heat exchange system 20 is schematically shown. As can be seen, the heat exchange device 21 of this system 20 is annular and extends continuously around the axis X over 360°.

[0092] It can also be seen that it occupies only a portion of the height H of the duct V2. The height h or radial dimension of the device 21 is only a portion of the height H or radial dimension of the duct V2. These heights H, h are measured in the radial direction relative to the axis X in the area of ​​the duct V2 where the device 21 is located. The height H of the duct V2 can vary along the axis X.

[0093] One of the problems observed in this type of device 21 is the disturbances and pressure drops generated in the air flow F2 , with the effect of increasing the specific fuel consumption of the turbine engine 1 . Optimizing the aerodynamic thermal performance of this system 20 is therefore very important.

[0094] In the document mentioned above, the applicant proposed a solution for optimizing the integration of this type of device 21 in a duct. Figure 4. The idea is to slow the velocity of the airflow through the device 21. The airflow through the device 21 is very turbulent. Slowing the velocity of the airflow entering the device 21 allows its aerodynamic thermal performance to be optimized, thereby minimizing the pressure drop for a given amount of heat dissipation. Control of the flow through the device 21 can be achieved by combining the device 21 with a diverging portion 24 and a converging portion 25 at the inlet. The diverging portion 24 upstream of the device 21 is configured to compress and decelerate the airflow entering the device 21, and the converging portion 25 downstream of the device 21 is configured to accelerate and expand the airflow exiting the device.

[0095] At the inlet of device 21, the deceleration factor is inversely proportional to the height ratio h / h0, where h is the height described above and h0 is the height at the inlet of diverging portion 24. Note that the slower the flow, the lower the pressure drop produced by device 21. At the outlet of device 21, the acceleration factor is inversely proportional to the height ratio h / h3, where h3 is the height at the outlet of diverging portion 25.

[0096] Figure 5 A perspective view of a portion of a heat exchange device 21 is shown. The figure shows a heat exchange matrix 26, which is sandwiched between a fairing 27 and the walls 22, 23 carrying the device 21. The converging portion 25 and the diverging portion 24 may be formed by the ends of the fairing 26, as in the example shown.

[0097] exist Figure 5 In the figures and other drawings, arrows are used to schematically indicate the oil circuit 28 .

[0098] 6a and 6b schematically illustrate alternative examples of heat exchange systems 20. FIG.

[0099] In the case of FIG. 6 a , the system 20 comprises an annular heat exchange device 21 which is segmented and comprises two sectors, each sector having an angular extent of approximately 180°.

[0100] In the case of FIG. 6 b , the system 20 comprises an annular heat exchange device 21 which is segmented and comprises four sectors, each sector having an angular extent of approximately 90°.

[0101] In Figures 6a-6b, the heat exchange device 21 extends over the entire height H of the duct 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 duct ( Figure 7 ).

[0102] The present invention is an improvement to this technology and provides a number of embodiments. Figure 8 and shown below.

[0103] One of the characteristics of the present invention is that the heat exchange system comprises at least two annular heat exchange devices, which are arranged in a staggered manner such that the heat exchange substrates of the devices are axially spaced apart from each other.

[0104] exist Figure 8 In the illustrated first embodiment of the present invention, the heat exchange system 20 comprises:

[0105] two annular walls, respectively an outer wall 22 and an inner wall 23 , extending around one another and around the same axis X and configured to define between them a flow duct V2 for a gas flow (for example, the secondary flow F2 ),

[0106] a first annular heat exchange device 21 extending about the axis X and carried by one of the walls, here the outer wall 22 , and situated in the duct V2 , this first device 21 comprising a heat exchange matrix 26 interposed between this wall 22 and a fairing 27 having a predetermined diameter D1 measured at the axial center of the heat exchange matrix 26 of this first device 21 , and

[0107] a second annular heat exchange device 30 extending about the axis X and situated in the duct V2, this second device 30 comprising a heat exchange matrix 31 axially spaced apart from the heat exchange matrix 26 of the first device 21 and interposed between the fairing 27 of the first device 21 and another fairing 32 of the second device 30, the fairing 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.

[0108] Figure 8 The heat exchange matrices 26 , 31 of the devices 21 , 30 are shown axially spaced apart in the duct V2 by an axial distance L. In the example shown, the device 21 situated on the outer wall 22 is situated downstream of the device 30 .

[0109] exist Figure 8 In the embodiment shown, D2 is greater than D1 , ie the outer peripheral portion of the heat exchange matrix 31 of the second device 30 is aligned in the axial direction with the inner peripheral portion of the heat exchange matrix 26 of the first device 21 .

[0110] Preferably, these devices 21 , 30 are air-oil devices, and for example surface devices, and each device comprises an oil circuit 28 in addition to a heat exchange matrix 26 , 31 situated in the duct V2 and configured to be swept by the air flow F2 , as described above.

[0111] Therefore, the devices 21, 30 have a common fairing 27,

[0112] The heat exchange matrix 26 of the device 21 is covered by an annular fairing 27 which extends axially upstream here to form an outer fairing for the heat exchange matrix 31 of the device 30. This fairing 27 is therefore located at the inner periphery of the heat exchange matrix 26 of the device 21 and at the outer periphery of the heat exchange matrix 31 of the device 30. The heat exchange matrix 31 of the device 30 is also connected to a further fairing 32 which is therefore located at the inner periphery of this heat exchange matrix 31.

[0113] The fairing 27 of the first device 21 comprises a plurality of successive axial sections along the axis X, namely:

[0114] an upstream end section 27 a situated upstream of the heat exchange matrix 31 of the second device 30 ,

[0115] a section 27b extending at the outer periphery of the heat exchange matrix 31 of the second device 30,

[0116] an intermediate section 27 c extending axially between the heat exchange matrix 31 of the second device 30 and the heat exchange matrix 26 of the first device 21 ,

[0117] a section 27d extending at the inner periphery of the heat exchange matrix 26 of the first device 21 , and

[0118] A downstream end section 27 e , which is situated downstream of the heat exchange matrix 26 of the first device 21 .

[0119] The fairing 32 of the second device 30 comprises:

[0120] an upstream end section 32 a situated upstream of the heat exchange matrix 31 of the second device 30 ,

[0121] a section 32b situated at the inner periphery of the heat exchange matrix 31 of the second device 30, and

[0122] A downstream end section 32 c situated downstream of the heat exchange matrix 31 of the second device 30 .

[0123] It can be seen that each of the upstream end sections 27a, 32a forms a diverging portion, and each of the downstream end sections 27e, 32c forms a converging portion.

[0124] In the example shown, the end sections 27a, 27e, 32a, 32c each have a frustoconical shape.

[0125] The fairing 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 smaller than D2. Figure 8 middle:

[0126] H1 denotes the diameter at the free upstream end of the fairing 32 or of the upstream end section 32 a of the fairing 32 ,

[0127] - H2 represents the diameter of the downstream end of the upstream end section 32a of the fairing 32,

[0128] - H3 represents the diameter of the upstream end of the downstream end section 32c of the fairing 32,

[0129] H4 denotes the diameter at the free downstream end of the fairing 32 or of the downstream end section 32 c of the fairing 32 ,

[0130] H5 denotes the diameter at the free upstream end of the fairing 27 or of the upstream end section 27a of this fairing 27,

[0131] H6 represents the diameter of the downstream end of the upstream end section 27a of the fairing 27,

[0132] - H7 denotes the diameter at the upstream end of the intermediate section 27c,

[0133] - H8 denotes the diameter at the downstream end of the intermediate section 27c,

[0134] - H9 represents the diameter at the upstream end of the downstream end section 27e of the fairing 27, and

[0135] H10 denotes the diameter at the free downstream end of the fairing 27 or of the downstream end section 27 e of this fairing 27 .

[0136] These diameters are measured relative to the axis X.

[0137] In the example shown:

[0138] - H1 is in particular greater than or equal to H2, H5 and H6, H2 may also be the maximum diameter of the system 20,

[0139] - H5 is in particular greater than H2 and H6, H2 can also be the maximum diameter of the fairing 27,

[0140] -H7 is particularly larger than H8, H3 and H4,

[0141] -H2 and H3 are larger than H8 and H9.

[0142] As mentioned above, each of the devices 21 , 30 may comprise a single heat exchanger, or may be segmented and comprise two or more heat exchangers distributed around the axis X.

[0143] In the example shown, the device 21 situated on the right side of the drawing occupies in the duct a height h1 which is comprised between 20% and 50% of the height hv1 of the duct.

[0144] The device 30 on the left side of the drawing occupies a height h2 in the duct that is between 10% and 30% of the height hv2.

[0145] The height h3 or radial dimension of the heat exchange matrix 26 of the first device 21 is greater than or equal to the height h4 or radial dimension 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 heights hv1, hv2 or radial dimensions of the duct V2 measured at these devices 21, 30.

[0146] It will be understood that an outer peripheral portion of the air flow F2 flowing in the duct (e.g., between 5% and 50% of the flow) will be used in the devices 21, 30, and the remainder of the flow will bypass the devices 21, 30. The air intended for the devices will be divided into a first inner peripheral portion (representing, for example, 2.5% to 25% of the flow) that will pass through the device 30 and the remaining outer peripheral portion (representing, for example, 2.5% to 25% of the flow) that will pass through the device 21.

[0147] Figure 9 The second embodiment shown differs from the first embodiment in that the fairings 27 , 32 each have a curved or wavy shape.

[0148] Furthermore, in the example shown, D3 is smaller than D1. In addition, H2 and H3 are smaller than H8 and H9.

[0149] In the example shown, it can be seen that the section of the fairing 27 that extends around the periphery of the heat exchange matrix of the second device 30 has a recess facing the inner wall 23. The cross section of the fairing 27 is generally curved or wavy. It can also be seen that the fairing 32 is substantially curved on one side of the inner wall 23.

[0150] Figure 9 The system shown is based on Figure 8 Operates in a similar manner.

[0151] Figure 10 The third embodiment shown differs from the second embodiment in that, in addition to the means 21 , 30 located on the outer wall 22 , similar means 21 ′, 30 ′ are located on the inner wall 23 .

[0152] Therefore, the heat exchange system 20 also includes means 21, 30:

[0153] another first annular heat exchange device 21 ′ extending about the axis X and carried by the inner wall 23 and situated in the duct V2, this first device 21 comprising a heat exchange matrix 26 ′ interposed between this wall 23 and a fairing 27 ′ having a predetermined diameter D1 ′ measured at the axial center of the heat exchange matrix 27 of this first device 21 ′, and

[0154] a second annular heat exchange device 30′ extending about the axis X and situated in the duct V2, this second device 30′ comprising a heat exchange matrix 31′ axially spaced apart from the heat exchange matrix 26′ of the first device 21′ and interposed between the fairing 27′ of the first device 21′ and a further fairing 32′ of the second device 30, the fairing 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′.

[0155] Figure 10 The heat exchange matrices 27', 31' of the devices 21', 30' are shown axially spaced apart in the duct V2 by an axial distance L'. In the example shown, the device 21' on the inner wall 23 is located downstream of the device 30'.

[0156] In this embodiment, D2' is smaller than D1', ie the inner peripheral portion of the heat exchange matrix 31' of the second device 30' is aligned in the axial direction with the outer peripheral portion of the heat exchange matrix 26' of the first device 21'.

[0157] Preferably, these devices 21 ′, 30 ′ are of the air-oil type and each device comprises an oil circuit 28 ′ in addition to a heat exchange matrix 26 ′, 31 ′ situated in the duct V2 and configured to be swept by the air flow F2 , as described above.

[0158] The devices 21 ′, 30 ′ have a common fairing 27 ′.

[0159] The heat exchange matrix 26' of the device 21' is covered by an annular fairing 27' which extends axially upstream to form an outer fairing for the heat exchange matrix 31' of the device 30'. Thus, this fairing 27' is located at the outer periphery of the heat exchange matrix 26' of the device 21' and at the inner periphery of the heat exchange matrix 31' of the device 30'. The heat exchange matrix 31' of the device 30' is also connected to a further fairing 32' which is therefore located at the outer periphery of the surface exchangers 31'.

[0160] The fairing 27' of the first device 21' comprises a plurality of successive axial sections along the axis, namely:

[0161] an upstream end section 27a' situated upstream of the heat exchange matrix 31' of the second device 30',

[0162] a section 27b' extending at the inner periphery of the heat exchange matrix 31' of the second device 30',

[0163] an intermediate section 27c ′ extending axially between the exchange matrix 31 ′ of the second device 30 ′ and the heat exchange matrix 26 ′ of the first device 21 ′,

[0164] a section 27d' extending at the outer periphery of the heat exchange matrix 26' of the first device 21', and

[0165] A downstream end section 27e' situated downstream of the heat exchange matrix 26' of the first device 21'.

[0166] The fairing 32' of the second device 30' comprises:

[0167] an upstream end section 32a ′ situated upstream of the heat exchange matrix 31 ′ of the second device 30 ′,

[0168] a section situated at the outer periphery of the heat exchange matrix 31 ′ of the second device 30 ′, and

[0169] A downstream end section 32c ′ situated downstream of the heat exchange matrix 31 ′ of the second device 30 ′.

[0170] It can be seen that each of the upstream end sections 27a', 32a' forms a diverging section and each of the downstream end sections 27e', 32c' forms a converging portion.

[0171] In the example shown, the end sections 27a', 27e', 32a', 32c' each have a curved shape.

[0172] The fairing 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'.

[0173] exist Figure 8 middle:

[0174] H1′ denotes the diameter at the free upstream end of the fairing 32′ or of the upstream end section 32a′ of the fairing 32′,

[0175] - H2' represents the diameter of the upstream end section 32a' of the fairing 32' at the downstream end,

[0176] - H3' represents the diameter of the upstream end of the downstream end section 32c' of the fairing 32',

[0177] - H4' denotes the diameter at the free downstream end of the fairing 32' or of the downstream end section 32c' of this fairing 32',

[0178] - H5' denotes the diameter at the free upstream end of the fairing 27' or of the upstream end section 27a' of this fairing 27',

[0179] - H6' represents the diameter of the upstream end section 27a' of the fairing 27' at the downstream end,

[0180] - H7' denotes the diameter at the upstream end of the intermediate section 27c',

[0181] - H8' denotes the diameter at the downstream end of the intermediate section 27c',

[0182] - H9' represents the diameter at the upstream end of the downstream end section 27e' of the fairing 27', and

[0183] H10 ′ denotes the diameter at the free downstream end of the fairing or of the downstream end section 27 e ′ of this fairing 27 ′.

[0184] These diameters are measured relative to the axis X.

[0185] In the example shown:

[0186] - H1' is in particular less than or equal to H2', H3 and H4',

[0187] - H5' is particularly smaller than H2', H3' and H6',

[0188] - H7' is particularly smaller than H8', H3' and H4',

[0189] -H2' and H3' are larger than H8' and H9'.

[0190] As mentioned above, each of the devices 21 ′, 30 ′ may comprise a single heat exchanger, or may be segmented and comprise two or more heat exchangers distributed around the axis X.

[0191] In the example shown, the device 21' on the right side of the drawing occupies a height h1' in the duct between 20% and 50% of the height hv1' of the duct. The device 30' on the left side of the drawing occupies a height h2' in the duct between 10% and 30% of the height hv2'.

[0192] The height h3' or radial dimension of the heat exchange matrix 26' of the first device 21' is greater than or equal to the height h4' or radial dimension 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 heights hv1, hv2 or radial dimensions of the duct V2 measured at these devices 21', 30'.

[0193] Alternatively, the heat exchange system 20 may include the devices 21 ′, 30 ′ only on the inner wall 23 side.

[0194] It will be understood that the outer peripheral portion of the air flow F2 flowing in the duct will be used in the devices 21, 30, as described above. Of the rest of the air flow, the inner peripheral portion will be used in the devices 21', 30' and will be divided into a first outer peripheral portion that will pass through the device 30' and the remaining inner peripheral portion that will pass through the device 21'.

[0195] Figure 11 The fourth embodiment shown differs from the second embodiment in that the heat exchange system 20 comprises a third annular heat exchange device 40 extending around the axis X and located in the duct V2.

[0196] Therefore, the system includes:

[0197] A third device 40 comprising a heat exchange matrix 41 is axially spaced apart from the heat exchange matrices 26 , 31 of the devices 21 , 30 and is interposed between the fairing 32 of the second device 31 and another fairing 42 of the third device 40 .

[0198] The second device fairing 32 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 .

[0199] In the example shown, D4 is greater than D3.

[0200] The upstream end section 32a of the fairing 32 of the second device 30 is divided into a plurality of parts, including:

[0201] an upstream portion 32a1 situated upstream of the heat exchange matrix 41 of the third device 40,

[0202] - an intermediate portion 32a2 located at the outer periphery of the heat exchange matrix 41 of the third device 40, and

[0203] A downstream portion 32 a 3 situated downstream of the heat exchange matrix 41 of the third device 40 .

[0204] The fairing 42 of the third device 40 comprises:

[0205] an upstream end section 42 a situated upstream of the heat exchange matrix 41 of the third device 40 ,

[0206] a section 42b situated at the inner periphery of the heat exchange matrix 41 of the third device 40, and

[0207] A downstream end section 42 c situated downstream of the heat exchange matrix 41 of the third device 40 .

[0208] It can be seen that the upstream end sections and portions 27a, 32a1 and 42a form divergent portions and the downstream end sections 27e, 32c, 42c form convergent portions. In the example shown, the end sections and portions 27a, 32a1, 42a, 27e, 32c, 42c each have a curved shape.

[0209] The fairing 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.

[0210] exist Figure 11 middle:

[0211] H11 denotes the diameter at the free upstream end of the fairing 42 or of the upstream end section 42 a of the fairing 42 ,

[0212] H12 represents the diameter of the upstream end section 42a of the fairing 42 at the downstream end,

[0213] H13 represents the diameter of the upstream end of the downstream end section 42 c of the fairing 42 ,

[0214] H14 denotes the diameter at the free downstream end of the fairing 42 or of the downstream end section 42 c of this fairing 42 .

[0215] These diameters are measured relative to the axis X.

[0216] In the example shown:

[0217] H11 is in particular greater than or equal to H12 , H1 and H5 , and may be the maximum diameter of the system 20 .

[0218] As mentioned above, each of the devices 21 , 30 may comprise a single heat exchanger, or may be segmented and comprise two or more heat exchangers distributed around the axis X.

[0219] The height h5 or radial dimension of the heat exchange matrix 41 of the third device 40 is less than or equal to the height h4 or radial dimension 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 heights hv1, hv2, hv3 or radial dimensions of the ducts measured at these devices 21, 30, 40.

[0220] It will be understood that the outer peripheral portion of the air flow F2 flowing in the duct will be used in the devices 21, 30, 40, and the remaining portion of the flow will bypass the devices 21, 30, 40. The air intended for the devices will be divided into a first inner peripheral portion that will pass through the device 40, a middle portion that will pass through the device 30, and the remaining outer peripheral portion that will pass through the device 21.

[0221] Figure 12 The fifth embodiment shown is Figure 1 The embodiment shown differs in that the second device 30 is located downstream of the first device 21 instead of upstream of the first device 21 .

[0222] The heat exchange matrix 26 of the device 21 is covered by an annular fairing 27 which is extended axially downstream to form an outer fairing for the heat exchange matrix 31 of the device 30. This fairing 27 is therefore located at the inner periphery of the heat exchange matrix 26 of the device 21 and at the outer periphery of the heat exchange matrix 31 of the device 30. The heat exchange matrix 31 of the device 30 is also connected to a further fairing 32 which is therefore located at the inner periphery of this heat exchange matrix 31.

[0223] The fairing 27 of the first device 21 comprises a plurality of successive axial sections along the axis X, namely:

[0224] an upstream end section 27 a situated upstream of the heat exchange matrix 26 of the first device 21 ,

[0225] a section 27b extending at the inner periphery of the heat exchange matrix 26 of the first device 21 ,

[0226] an intermediate section 27 c extending axially between the heat exchange matrix 26 of the first device 21 and the heat exchange matrix 31 of the second device 32 ,

[0227] a section 27d extending at the outer periphery of the heat exchange matrix 31 of the second device 30, and

[0228] A downstream end section 27 e , which is situated downstream of the heat exchange matrix 31 of the second device 30 .

[0229] The fairing 32 of the second device 30 comprises:

[0230] an upstream end section 32 a situated upstream of the heat exchange matrix 31 of the second device 30 ,

[0231] a section 32b situated at the inner periphery of the heat exchange matrix 31 of the second device 30, and

[0232] A downstream end section 32 c situated downstream of the heat exchange matrix 31 of the second device 30 .

[0233] It can be seen that each of the upstream end sections 27a, 32a forms a diverging portion, and each of the downstream end sections 27e, 32c forms a converging portion.

[0234] In the example shown, the end sections 27a, 27e, 32a, 32c each have a frustoconical shape.

[0235] In the example shown, D3 is smaller than D1. D2 is larger than D1.

[0236] exist Figure 12 middle:

[0237] H1 denotes the diameter at the free upstream end of the fairing 32 or of the upstream end section 32 a of the fairing 32 ,

[0238] - H2 represents the diameter of the downstream end of the upstream end section 32a of the fairing 32,

[0239] - H3 represents the diameter of the upstream end of the downstream end section 32c of the fairing 32,

[0240] H4 denotes the diameter at the free downstream end of the fairing 32 or of the downstream end section 32 c of the fairing 32 ,

[0241] H5 denotes the diameter at the free upstream end of the fairing 27 or of the upstream end section 27a of this fairing 27,

[0242] H6 represents the diameter of the downstream end of the upstream end section 27a of the fairing 27,

[0243] - H7 denotes the diameter at the upstream end of the intermediate section 27c,

[0244] - H8 denotes the diameter at the downstream end of the intermediate section 27c,

[0245] - H9 represents the diameter at the upstream end of the downstream end section 27e of the fairing 27, and

[0246] H10 denotes the diameter at the free downstream end of the fairing 27 or of the downstream end section 27 e of this fairing 27 .

[0247] These diameters are measured relative to the axis X.

[0248] In the example shown:

[0249] - H1 is greater than or equal to H2, but in particular less than H5 and H6,

[0250] -H5 may be the maximum diameter of the system 20,

[0251] -H7 is particularly smaller than H8, H9 and H10,

[0252] -H2 and H3 are smaller than H8 and H9.

[0253] As mentioned above, each of the devices 21 , 30 may comprise a single heat exchanger, or may be segmented and comprise two or more heat exchangers distributed around the axis X.

[0254] In the example shown, the device 21 on the left side of the drawing occupies a height h1 in the duct between 20% and 50% of the height hv1 of the duct. The device 30 on the right side of the drawing occupies a height h2 in the duct between 10% and 30% of the height hv2.

[0255] The height h3 or radial dimension of the heat exchange matrix 26 of the first device 21 is greater than or equal to the height h4 or radial dimension 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 heights hv1, hv2 or radial dimensions of the duct V2 measured at these devices 21, 30.

[0256] It will be understood that the peripheral portion of the air flow F2 flowing in the duct will be consumed by the device 21 and the remainder of the flow will bypass the device 21. Of the air flow bypassing the device 21, a portion of the peripheral portion will be absorbed and will pass through the device 30, while the remainder will bypass the device 30.

[0257] Figure 13 The sixth embodiment shown is the same as Figure 12 The embodiment shown differs in that the fairings 27 , 32 are curved.

[0258] Figure 13 The system shown is based on Figure 12 Operates in a similar manner.

[0259] Figure 14 The embodiment shown is similar to Figure 10 The embodiment shown, except that the second device 30, 30' is arranged downstream of the first device 21, 21' and is therefore reference Figure 12 and Figure 13 The type of description.

[0260] It will be understood that the outer portion of the air flow F2 flowing in the duct will be used in the devices 21, 30, as described above. Of the remainder of the air flow, the inner portion will be used in the devices 21', 30' and will be divided into a first inner portion that will pass through the device 21' and another inner portion of the air flow that will bypass the device 21' and enter the device 30'.

[0261] exist Figure 15 In the embodiment shown, the devices 21 and 30 are supported by the outer wall 22 and the inner wall 23, respectively.

[0262] For example, the first device 21 is similar to the above Figure 1 and Figure 2 The device described.

[0263] The second device 30 is located upstream of the first device 21 and comprises a heat exchange matrix 31 axially spaced apart from the heat exchange matrix 26 of the first device 21 and interposed between the fairing 27 and the wall 23 of the first device 21 .

[0264] It should therefore be understood that as long as the heat exchange matrix 26 of the first device 21 extends between the fairing 27 and the outer wall 22, and the heat exchange matrix 31 of the second device 30 extends between the fairing 27 and the inner wall 23, the devices 21, 30 share the same fairing 27 and there are no other fairings in the system 20.

[0265] The fairing 27 includes:

[0266] an upstream end section 27 a situated upstream of the heat exchange matrix 31 of the second device 30 and forming a diverging portion,

[0267] a section 27b extending at the outer periphery of the exchange matrix 31 of the second device 30,

[0268] an intermediate section 27 c extending axially between the heat exchange matrix 31 of the second device 30 and the heat exchange matrix 26 of the first device 21 ,

[0269] a section 27d extending at the inner periphery of the exchange matrix 26 of the first device 21 , and

[0270] A downstream end section 27 e forming a taper and situated downstream of the heat exchange matrix 26 of the first device 21 .

[0271] exist Figure 15 middle:

[0272] - H5" denotes the diameter at the free upstream end of the fairing 27 or of the upstream end section 27a of the fairing 27,

[0273] -H6" represents the diameter of the downstream end of the upstream end section 27a of the fairing 27,

[0274] -H7" represents the diameter at the upstream end of the intermediate section 27c,

[0275] -H8" represents the diameter at the downstream end of the intermediate section 27c,

[0276] - H9" represents the diameter at the upstream end of the downstream end section 27e of the fairing 27, and

[0277] H10″ denotes the diameter at the free downstream end of the fairing 27 or of the downstream end section 27 e of this fairing 27 .

[0278] These diameters are measured relative to the axis X.

[0279] In the example shown:

[0280] -H5" is significantly larger than H6,

[0281] -H7" is particularly larger than H8.

[0282] As mentioned above, each of the devices 21 , 30 may comprise a single heat exchanger, or may be segmented and comprise two or more heat exchangers distributed around the axis X.

[0283] In the example shown, the device 21 situated on the right side of the drawing occupies in the duct a height h1 which is between 50% and 80% of the height hv1 of the duct.

[0284] The device 30 on the left side of the drawing occupies a height h2 in the duct that is between 50% and 80% of the height hv2.

[0285] The height h2 or radial dimension of the heat exchange matrix 26 of the first device 21 is greater than or equal to the height h4 or radial dimension 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 heights hv1, hv2 or radial dimensions of the ducts measured at these devices 21, 30.

[0286] It will be understood that the inner peripheral portion of the air flow F2 flowing in the duct will enter the device 30, while the remaining portion of the air flow will pass through the device 21. Thus, the entire air flow is used to exchange heat.

[0287] Mounting the devices partially stacked with an axial offset limits the axial and radial space occupied by the devices. By limiting the radial footprint, a higher reduction ratio can be achieved within each of the devices.

Claims

1. A turbine engine for an aircraft, comprising a heat exchange system (20), the system comprising: - two annular walls, respectively an outer wall (22) and an inner wall (23), extending around one another and around the same axis (X) and configured to define between them a flow duct (V2) for the air flow (F2), a first annular heat exchange device (21) extending around said axis (X) and carried by one of said walls (22, 23) and located in said duct (V2), said first device (21) comprising a heat exchange matrix (26) interposed between said wall (22) and a fairing (27), said fairing having a predetermined diameter D1 measured at the axial center of the heat exchange matrix (26) of said first device (21), Characterized in that, the heat exchange system further comprises: - a second annular heat exchange device (30) extending around said axis (X) and located in said duct (V2), said second device (30) comprising a heat exchange matrix (31) axially spaced from the heat exchange matrix (26) of said first device (21) and interposed between a fairing (27) of said first device (21) and an opposite wall (23) or another fairing (32) of said second device (30), said fairing (27) of said first device (21) having a predetermined diameter D2 measured at the axial center of the heat exchange matrix (31) of said second device (30), and wherein: - when said first means (21) is carried by said outer wall (22), D2 is greater than D1, or - When said first means (21) are carried by said inner wall (23), D2 is smaller than D1.

2. The turbine engine according to claim 1, characterized in that The fairing (27) of the first device (21) comprises a plurality of successive axial sections along the axis (X): an upstream end section (27a) situated upstream of the heat exchange matrix (31) of the second device (30); a section (27b) extending at the periphery of the heat exchange matrix (31) of the second device (30); an intermediate section (27c) extending 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) extending at the periphery of the heat exchange matrix (26) of the first device (21); and a downstream end section (27e) situated downstream of the heat exchange matrix (26) of the first device (21), or - an upstream end section (27a) extending upstream of the heat exchange matrix (26) of the first device (21); a section (27b) extending at the periphery of the heat exchange matrix (26) of the first device (21); an intermediate section (27c) extending 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) extending at the periphery of the heat exchange matrix (31) of the second device (30); and a downstream end section (27e) located downstream of the heat exchange matrix (31) of the second device (30).

3. The turbine engine according to claim 2, characterized in that The second device (30) includes the other fairing (32), which includes: an upstream end section (32a) located upstream of the heat exchange matrix (31) of the second device (30); a section (32b) located at the periphery of the heat exchange matrix (31) of the second device (30); and a downstream end section (32c) located downstream of the heat exchange matrix (31) of the second device (30).

4. A turbine engine according to any one of the preceding claims, characterized in that The further fairing (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), and wherein: - when said first means (21) is carried by said outer wall (22), D3 is greater than D1, or - When said first means (21) are carried by said inner wall (23), D3 is smaller than D1.

5. Turbine engine according to any one of the preceding claims, characterized in that The turbine engine further comprises: - a third annular heat exchange device (40) of the surface type, extending around the axis (X) and located in the duct (V2), the third device (40) comprising a heat exchange matrix (41), the heat exchange matrix of the third device being axially spaced apart from the heat exchange matrices (26, 31) of the first and second devices (21, 30) and being interposed between a fairing (32) of the second device (30) and another of the walls (22) or another fairing (42) of the third device (40), the other fairing (32) of the second device (30) having 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), and wherein: - when said first means (21) is carried by said outer wall (23), D4 is greater than D3, or - When said first means (21) are carried by said inner wall (22), D4 is smaller than D3.

6. The turbine engine according to claim 5, characterized in that The third device (40) includes the other fairing (42), which includes: an upstream end section (42a) located upstream of the heat exchange matrix (41) of the third device (40); a section (42b) located at the periphery of the heat exchange matrix (41) of the third device (40); and a downstream end section (42c) located downstream of the heat exchange matrix (41) of the third device (40).

7. The turbine engine according to claim 2, 3 or 6, characterized in that: The or each upstream end section (27a, 32a, 42a) forms a diverging portion, and the or each downstream end section (27e, 32c, 42c) forms a converging portion.

8. The turbine engine according to claim 2, 3, 6 or 7, characterized in that: The end sections (27a, 27e, 32a, 32c, 42a, 42c) have a frustoconical or circular shape.

9. A turbine engine according to any one of the preceding claims, characterized in that The height (h3) or radial dimension of the heat exchange matrix (26) of the first device (21) is greater than or equal to the height (h4) or radial dimension of the heat exchange matrix (31) of the second device (30).

10. The turbine engine according to any one of claims 1 to 9, characterized in that 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 smaller than the heights (hv1, hv2) or radial dimensions of the duct (V2) measured at these devices (21, 30).

11. The turbine engine according to any one of claims 1 to 9, characterized in that 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 greater than the heights (hv1, hv2) or radial dimensions of the ducts measured at these devices (21, 30).

12. A turbine engine according to any one of the preceding claims, characterised in that Each of the outer and inner walls (22, 23) carries the first heat exchange means (21) associated with the second heat exchange means (30) or even the third heat exchange means (30).

Images