Counterflow heat exchanger for turbomachinery, turbomachinery and heat exchanger manufacturing process

Abstract

A heat exchanger (1) for a turbomachine comprising: an internal heat exchange wall (21) between a first circuit and a second circuit, the first circuit being configured to receive a first fluid flow and the second circuit being configured to receive a second fluid flow; an external wall (22) surrounding the first and second circuits; at least one breakable junction portion (30), the breakable junction portion (30) comprising: a first portion (31) connected to the internal heat exchange wall (21) and a second portion (32) connected to the external wall (22), and the mechanical resistance to rupture between the first portion (31) and the second portion (32) being less than the mechanical resistance to rupture between the first portion (31) and the internal heat exchange wall (21) and between the second portion (32) and the external wall (22). Figure for the abstract: Fig. 7.

Description

Description Title of the invention: Counter-current heat exchanger for turbomachine, turbomachine and manufacturing process of the exchanger technical field

[0001] = The present exposition relates to heat exchangers for a turbomachine, in in particular a counter-current heat exchanger. Previous technique

[0002] =— A counter-current heat exchanger is known for a turbomachine, allowing the gas used to generate mechanical power to be heated on the drive shaft, upstream of its passage through the combustion chamber, thanks to the thermal energy extracted from the combustion gas exiting the chamber combustion. We also know of a heat exchanger that can supply the system with environmental control of an aircraft cabin, or enabling the maintenance different aircraft systems within their temperature operating range, by example to ensure compliance with mechanical tolerance values.

[0003] — During the manufacture of the heat exchanger in one piece, typically by In additive manufacturing, the lack of material continuity between an outer wall and a The internal wall can cause deformations that result in the appearance of cracks in the within the heat exchanger, or even a failure to comply with manufacturing tolerances. These Manufacturing defects can lead to poor fluid flow in the heat exchanger or even a fluid leak, resulting in poor thermal efficiency the heat exchanger. These problems associated with the manufacture of the heat exchanger are all the more more present in the case of manufacturing by additive methods.

[0004] — However, ensuring continuity of material between the outer and inner walls can cause a transmission of stresses between parts subjected to stresses extreme thermomechanical stresses during operation of the exchanger, thus being able to cause a rupture within the interchange. Description of the invention

[0005] The present description aims to remedy at least some of these drawbacks.

[0006] To this end, the present description relates to a heat exchanger for a turbomachine. including: an internal heat exchange wall between a first circuit and a second circuit, the first circuit being configured to receive an initial flow of fluid and the second circuit being configured to receive a second flow of fluid; an external wall surrounding the first circuit and the second circuit; at least one breakable junction section, the breakable junction section comprising: a first section connected to the inner heat exchange wall and a second section connected to the outer wall, and the mechanical resistance to breakage between the first part and the second part being less than the mechanical resistance to breakage between the first part and the internal heat exchange wall and the mechanical resistance to breakage between the first part and the second part being less than the mechanical resistance to breakage between the second part and the external wall. The term "fluid" refers to any type of liquid or gas, including any type of turbomachinery liquid or gas. For example, "fluid" can refer to combustion gases, air, lubricating oil, etc. A wall is understood to be a material structure having a volume, and not a face or surface of zero volume. The internal wall is defined as a wall that separates the first fluid flow from the second fluid flow within the heat exchanger. An external wall is defined as a wall that separates an internal volume of the heat exchanger from a volume located outside the heat exchanger. An internal heat exchange wall is therefore a wall of the heat exchanger that is not an external wall. Generally speaking, "internal" refers to an element inside the heat exchanger, and "external" refers to an element outside the heat exchanger. A break between two parts is defined as a complete or partial rupture of the connection between the two parts. A break between two parts of a part is defined as a complete or partial rupture between said two parts. Mechanical resistance to breakage is defined as the mechanical resistance to breakage in response to simple or combined stresses, repeated or not, particularly in tension, compression, shear, and / or bending, or any other loading method known to those skilled in the art. In other words, the mechanical resistance to breakage between the first part and the second part is less than the mechanical resistance to breakage between the first part and the internal heat exchange wall, and the mechanical resistance to breakage between the first part and the second part is less than the mechanical resistance to breakage between the second part and the external wall if, following the application of a force on the assembly formed by the internal heat exchange wall, the external wall and the breakable junction part and causing breakage within said assembly, the breakage is located in the first part and / or the second part of the breakable junction part. The breakable junction section supports the internal heat exchange wall. thermal and the outer wall. Thus, before rupture, the breakable junction section supports both the inner heat exchanger wall and the outer wall. This reduces wall deformation during manufacturing, thereby improving adherence to manufacturing tolerances and, consequently, the manufacturability of the heat exchanger. In the event of mechanical or thermomechanical stress causing rupture, the rupture is localized and / or confined to the breakable section of the junction. This confinement of the rupture to the breakable section of the junction prevents damage to the internal wall of the heat exchanger and the external wall of the heat exchanger, thereby reducing the risk of leakage between the first and second fluid flows, or between the first and second fluid flows and the outside of the heat exchanger. Such a heat exchanger also has the advantage of being particularly suitable for manufacturing by a manufacturing process involving additive manufacturing methods, thus allowing for easier manufacturing of the heat exchanger. In some embodiments, the heat exchanger is a counter-current heat exchanger. In some embodiments, the heat exchanger is a plate and / or finned heat exchanger. In some embodiments, the plates and / or fins protrude from the internal heat exchange wall. In some embodiments, the breakable joining part has a minimum cross-section between 10% and 70% of the maximum cross-section of the breakable joining part, preferably between 20% and 50%. Unless otherwise stated, the dimensions indicated below correspond to the dimensions measured in the heat exchanger at ambient temperature in the absence of circulation of turbomachine fluids in the exchanger. The cross-sectional area of ​​the breakable junction portion is measured in a transverse plane, that is, a plane normal to the spacing direction. The spacing direction is the direction in which the breakable junction portion extends between the inner heat exchange wall and the outer wall. The term "direction" refers to an unoriented straight line. The term "sense" refers to an orientation along a straight line. Transverse direction is understood to mean a direction perpendicular to the spacing direction. Such dimensions of the breakable junction portion ensure stress concentration at the narrowing associated with the minimum cross-section, thus ensuring that the fracture is located in the breakable portion of junction, particularly at the narrowing. In some embodiments, the breakable joint portion has a minimum cross-section between 0.01 mm² and 5 mm², preferably between 0.05 mm² and 0.1 mm². Such a minimum cross-sectional value makes it possible to reduce an aerodynamic influence of the breakable junction part on a fluid flow between the internal heat exchange wall and the external wall. In some embodiments, a minimum length of the breakable joint portion along a fluid flow direction is between 0.1 mm and 5 mm, preferably between 0.3 mm and 3 mm. In a counter-current heat exchanger, the fluid flow direction is common to both the first and second fluid flows. In a counter-current heat exchanger, the first and second fluid flows flow in opposite directions. In some embodiments, the thickness of the breakable joint portion is between 0.05 mm and 4 mm, preferably between 0.1 mm and 2 mm. The thickness of the breakable joint section is measured along the spacing direction. The thickness of the breakable joint section corresponds to the distance between the inner joint wall and the outer wall. Such a distance between the inner and outer walls of the heat exchanger is small enough to limit the fluid flow circulating around the periphery of the heat exchanger—that is, the fluid flow bypassing the inner wall—and thus ensure that the majority of the fluid flow can contribute to heat exchange with the other fluid flow (the first and second fluid flows) via the inner wall. This limits the reduction in the heat exchanger's thermal efficiency. Such a distance between the inner heat exchange wall and the outer wall is high enough to prevent contact between the inner heat exchange wall and the outer wall, which would form a thermal bridge to the outside of the heat exchanger and reduce the thermal efficiency of the heat exchanger. In some embodiments, the heat exchanger comprises a plurality of breakable junction parts substantially aligned along a direction of fluid flow within the heat exchanger. This alignment ensures the support of the internal heat exchange wall and the external wall by the breakable junction part along the heat exchanger. Alignment also helps to reduce disturbance in fluid flow and thus prevent a reduction in the thermal efficiency of the heat exchanger. In some embodiments, the ratio of the length along the direction of fluid flow of a breakable joint portion to the distance between two consecutive breakable joint portions aligned along the direction of fluid flow is between 20% and 80%, preferably between 35% and 75%. Such a ratio ensures the support of the internal exchange wall and the external wall by the breakable exchange part along the direction of fluid flow. The invention also relates to a turbomachine comprising a heat exchanger according to the present invention. In some embodiments, the first circuit is connected to a compressor and the second circuit is connected to a turbine. The invention also relates to a method for manufacturing a heat exchanger comprising at least one additive manufacturing step, preferably a powder bed additive manufacturing step. The breakable junction part helps to reduce deformations associated with additive manufacturing, for example by supporting the internal heat exchange wall and the external wall during manufacturing, or by reducing deformations associated with thermal variations during manufacturing and / or operation of the exchanger. The breakable junction section thus allows for maintaining a maximum distance between the inner heat exchanger wall and the outer wall. This reduces the fluid flow bypassing the inner heat exchanger walls by passing through the space formed between the inner and outer walls, thereby preventing a reduction in the heat exchanger's thermal efficiency. The breakable junction section can, to a limited extent, form a thermal bridge between the inner wall of the heat exchanger and the exterior. Due to the mechanical strength properties of the breakable junction section, a break within the breakable junction section results in the rupture of the associated thermal bridge. Thus, the breakable junction section can contribute to strengthening the structure of the heat exchanger during its additive manufacturing process, without significantly degrading the heat exchanger's thermal efficiency once the breakable junction section is broken. Brief description of the drawings Other features and advantages of the object of this presentation will emerge from the following description of embodiments, given by way of non-limiting examples, with reference to the attached figures. [Fig.1] The [Fig.1] is a cross-sectional view of a turbomachine including a counter-current heat exchanger. [Fig.2] Fig.2 is a schematic perspective view of a counter-current heat exchanger. [Fig.3] The [Fig.3] is a schematic cross-sectional view along the section plane III-III of the [Fig.2]. [Fig. 4] Fig. 4 is a schematic view of one face of the heat exchanger. [Fig. 5] Fig. 5 is a perspective view corresponding to a magnification of the magnifying glass V of Fig. 4. [Fig.6] The [Fig.6] is a schematic cross-sectional view along section plane VI of the [Fig.5]. [Fig.7] The [Fig.7] is a perspective view of a breakable junction part according to an embodiment. [Fig.8] The [Fig.8] is a side view of a breakable junction part according to the embodiment. [Fig.9] The [Fig.9] is a projection along plane IX of a separable junction part according to the embodiment. Description of the implementation methods Figure [Fig.1] represents, in half-section along a vertical plane passing through its main axis A1-A1, a turbomachine 101 equipped with a counter-current heat exchanger, hereinafter referred to as "exchanger". The turbomachine 101 comprises, from upstream to downstream according to the circulation of the airflow, a radial air inlet duct 102, a compressor 103, a combustion chamber 104, a high-pressure turbine 105, and a free turbine 106. These different elements are installed inside a nacelle (not shown), so as to obtain a propulsion unit comprising the nacelle and the turbomachine 101. The airflow enters radially into the air supply duct 102, is compressed by the compressor 103 before being injected into the combustion chamber 104, where it is mixed with the fuel to cause combustion. The gases from the combustion chamber 104 cause a high-pressure turbine 104 to rotate, which in turn causes the compressor 103 to rotate, and a free turbine 106. As mentioned above, the turbomachine 101 is a turbomachine equipped with a heat exchanger 1. As illustrated schematically in [Fig. 1], such a heat exchanger is supplied with a first fluid flow 10 within a first internal circuit of the heat exchanger 1. The heat exchanger is supplied with a second fluid flow 20, different from the first fluid flow 10, within a second internal circuit of the heat exchanger 1. The first circuit and the second circuit do not communicate with each other, so the first fluid flow 10 and the second fluid flow 20 do not cannot mix, but can exchange heat through internal exchange walls 21 which will be described in relation to figures 3 to 5. In particular, in the embodiment of [Fig.1], the exchanger 1 is provided downstream of the free turbine 106, for example downstream of a nozzle 107. In figures 1 to 5, the arrows without filling schematically indicate the general direction of circulation of the first fluid flow 10 in the exchanger 1 and the arrows with full filling schematically indicate the general direction of circulation of the second fluid flow 20 in the exchanger 1. The exchanger | can for example have a roughly cubic or rectangular parallelepiped shape, as shown in [Fig.2]. In the embodiment of figures 2 to 9, the exchanger 1 is represented in an orthonormal XYZ coordinate system formed by the first direction X, the second direction Y and the third direction Z. The first direction X corresponds to the overall flow direction of the first fluid flow 10 and the second fluid flow 20 within the exchanger 1. The exchanger 1 includes internal heat exchange walls 21 separating the first fluid flow 10 and the second fluid flow 20, and external walls 22 surrounding the first fluid flow 10 and the second fluid flow 20. The internal heat exchange walls 21 prevent the mixing of the first fluid flow 10 and the second fluid flow 20 while allowing heat transfer between the first fluid flow 10 and the second fluid flow 20. The internal heat exchange walls 21 extend substantially in a plane formed by the first direction X and the third direction Z, making it possible not to disturb the overall direction of circulation of the first fluid flow 10 and the second fluid flow 20 in the exchanger 1 along the first direction X. The internal heat exchange walls 21 are fitted with plates and / or fins 24. The plates and fins 24 contribute to the heat exchange between the first fluid flow 10 and the second fluid flow 20. The plates and fins 24 thus improve the thermal efficiency of the exchanger 1. An exchanger 1 fitted with plates and / or fins is called a plate and / or fin heat exchanger. In order not to overload the drawing, not all the plates and fins 24 have been shown in [Fig.5]. It is understood that the plates and / or fins 24 can be arranged on all or part of the internal walls of the heat exchange 21, that is to say on all or part of the surface on the side of the first circuit and / or on all or part of the surface on the side of the second circuit. A plurality of internal heat exchange walls 21 is arranged to form successive layers in the second direction Y. The external walls 22 can be arranged on all or part of the outer perimeter of the exchanger |, with the exception of the inlets and outlets of the first fluid flow 10 and the second fluid flow 20. The fluid circulation within the exchanger | is thus limited to the circulation of the first fluid flow 10 and the second fluid flow 20 between their respective inlets and outlets. The external walls 22 also help to reduce heat exchange between, on the one hand, an internal volume of the exchanger 1 comprising the first fluid flow 10 and the second fluid flow 20, and on the other hand, a volume located outside the exchanger 1, so as to promote heat exchange between the first fluid flow 10 and the second fluid flow 20. At least one breakable junction portion 30 can be arranged between an internal heat exchange wall 21 and an external wall 22. In particular, a breakable junction portion 30 can be arranged between an internal heat exchange wall 21 and an external wall 22 in a position for which the internal heat exchange wall 21 and the external wall 22 are opposite each other, i.e. a position for which the distance between the internal heat exchange wall 21 and the external wall 22 is minimal. The structure of the breakable junction parts 30 will be described in more detail with respect to figures 7 to 9. As shown in [Fig.5], a plurality of breakable junction parts 30 can be arranged along the first direction X, in particular between the same internal heat exchange wall 21 and the same external wall 22. A plurality of breakable junction parts 30 can be arranged along the second direction Y, between an external wall 22 and separate internal heat exchange walls 21, Deformations may occur during the additive manufacturing of the exchanger |, resulting in the manufacture of an exchanger 1 outside the planned design tolerances, leading to a degradation of thermal performance or even damage to the exchanger 1. For example, such deformations can be caused by cantilevering parts during additive manufacturing, particularly internal heat exchange walls 21, making it difficult to properly control the distance between the internal heat exchange walls 21 and external walls 22. Furthermore, the operation of the exchanger 1 involves different fluid temperatures between the first fluid flow 10 and the second fluid flow 20, associated with thermomechanical constraints further complicating the proper control of the spacing between the internal heat exchange walls 21 and the external walls 22. Insufficient spacing between the internal heat exchange walls 21 and the external walls 22 would entail the risk of contact between the internal heat exchange walls 21 and the external walls 22, which could damage the internal heat exchange walls 21 and the external walls 22 and cause a leakage of fluid from one of the fluid circuits to the other of the fluid circuits or to the outside of the exchanger 1, or could constitute a thermal bridge to the outside of the exchanger 1 and thus a loss of thermal efficiency. Too high a spacing between the internal heat exchange walls 21 and the external walls 22 would increase the propensity of one of the fluid flows (the second fluid flow 20, according to the embodiment of [Fig.5]) to bypass the central parts of the exchanger 1, thus reducing the thermal efficiency of the exchanger 1. The breakable junction parts 30 thus allow the internal heat exchange walls 21 and the external walls 22 to be kept apart from each other, and in particular to reduce the variation in spacing between the internal heat exchange walls 21 and the external walls 22 in order to reduce the risks associated with too high and / or too low a spacing. Fig. 6 is a cross-sectional view along section plane VI of Fig. 5, representing an alignment of three breakable junction parts 30 between an internal heat exchange wall 21 and an external wall 22 along the first direction X. The breakable junction parts 30 have a length Imax along the first direction X of between 0.5 mm and 5 mm, preferably between | mm and 3 mm. The distance d along the first direction X between two breakable parts of junction 30 is between 0.5 mm and 20 mm, preferably between 1 mm and 5 mm. The ratio of the length along the first direction X of a breakable junction part 30 to the distance between two consecutive breakable junction parts 30 aligned along the first direction X is between 20% and 80%, preferably between 35% and 75%. These dimensions contribute to maintaining the spacing between the internal heat exchange walls 21 and the external walls 22 while limiting the formation of a thermal bridge between the internal heat exchange walls 21 and the external walls 22 by the breakable junction parts 30. The breakable junction parts 30 described will be the breakable junction parts 30 of figures 5 and 6, so that the first direction X, the second direction Y, the third direction Z and the associated orthonormal frame XYZ coincide with the directions of the orthonormal frame XYZ of the breakable junction parts 30. It is understood, however, that the frame XYZ in which the breakable junction parts 30 are described may be a frame specific to the breakable junction parts 30, for example when the breakable junction parts 30 are positioned differently between the inner heat exchange wall 21 and the outer wall 22. The breakable junction part 30 comprises a first part 31 connected to the internal heat exchange wall 21, and a second part connected to the external wall 22. The mechanical resistance to breakage between the first part 31 and the second part 32 is less than the mechanical resistance to breakage between the first part 31 and the internal heat exchange wall 21 and the mechanical resistance to breakage between the first part 31 and the second part 32 is less than the mechanical resistance to breakage between the second part 32 and the external wall 22. Thus, in the event of mechanical or thermomechanical stress causing rupture transmitted by the breakable part of the junction 30, the rupture will be localized in the breakable part of the junction 30, in particular between the first part 31 and the second part 32. The breakable junction portion 30 can then perform its function of supporting the internal heat exchange walls 21 and the external walls 22, reducing the risk of damage to the internal heat exchange walls 21 and the external walls 59 The characteristic dimensions of the breakable junction part 30 will be described in relation to the views of figures 6 to 9. The thickness h of the breakable part of the joint 30 is between 0.05 mm and 4 mm, or even between 0.1 mm and 4 mm, or even between 0.1 mm and 2 mm, preferably between 0.4 mm and 2 mm. The thickness h is equal to the distance between the inner junction wall 21 and the outer wall 22 connected by the breakable junction part 30. These thickness ranges h allow during the operation of the exchanger 1 to prevent contact between the internal heat exchange wall 21 and the external wall 22 while limiting the bypassing of the internal heat exchange walls 21 by the second fluid flow 20. The breakable junction portion 30 has a minimal transverse surface area at a position far from the internal heat exchange wall 21 and the external heat exchange wall 22. This increases the chances that the break will not propagate to the internal heat exchange walls 21 and the external walls 22. In the present embodiment, the cross-section of the breakable junction part 30 is rectangular in shape. However, it is understood that other cross-sectional shapes can be used to increase or reduce resistance to thermomechanical stresses or to reduce pressure losses of fluid flow around the breakable junction part, including ellipsoidal, ovoid or profiled shapes. The minimum cross-sectional area of ​​the breakable joint portion 30 is between 0.01 mm and 5 mm, preferably between 0.05 mm and 0.1 mm. In this embodiment, the minimum cross-section is measured in a plane formed by the first direction X and the second direction Y. The minimum cross-section of the breakable junction part 30 is between 10% and 70% of the maximum cross-section of the breakable junction part 30, preferably between 20% and 50%. The maximum cross-section is the maximum cross-section measured in a plane parallel to the plane of the minimum cross-section. Such a section ratio ensures proper maintenance of the internal heat exchange walls 21 and the external walls 22 during the manufacture of the exchanger 1, and concentrates stress to increase the chances of failure occurring in the breakable junction part 30. In the present embodiment, the first part 31 and the second part 32 are symmetrical. This further increases the likelihood that the rupture will be contained within the center of the breakable junction portion 30 and, in particular, will not propagate to the internal heat exchange walls 21 and the external walls 22. The breakable part of the junction 30 has a minimum length Imin along the first direction X of between 0.1 mm and 5 mm, or even between 0.1 mm and 4 mm, or even between 0.3 mm and 3 mm, preferably between 0.3 mm and 2.5 mm. The breakable part of the junction 30 has a minimum height tmin along the second direction Y of between 0.05 mm and 1.5 mm, preferably between 0.1 mm and 0.3 mm. The ratio between the minimum length Imin and the minimum height tmin is greater than 3, preferably greater than 5. In this way, the disturbance of the flow along the first direction X by the breakable part of the junction 30 is further reduced. The breakable part of the junction 30 has a maximum height tmax along the second direction Y of between 0.1 mm and 4 mm, preferably between 0.2 mm and 1 mm. The ratio between the maximum length Imax and the maximum height tmax is greater than 2, preferably greater than 5. Such dimensions along the first direction X along the second direction Y allow the breakable junction part 30 to extend mainly along the first direction X, or fluid flow direction, so as to reduce disturbances of the fluid flow along the first direction X, which could affect a part of the flow of said fluid and reduce the thermal efficiency of the exchanger 1. The maximum cross-section is the cross-section at the position where the length along the first direction X is equal to the maximum length Imax and the height along the second direction Ÿ is equal to the maximum height Imax. Preferably, the breakable parts of the plurality of breakable parts of junction 30 are regularly distributed along the first direction X and the second direction Y. The heat exchanger | has a structure that is particularly well-suited to production using additive manufacturing processes. A manufacturing process for heat exchanger 1 can therefore be implemented, entirely or partially, by additive manufacturing, for example by a laser powder bed fusion process. Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Demands

1. Heat exchanger (1) for turbomachinery comprising: an internal heat exchange wall (21) between a first circuit and a second circuit, the first circuit being configured to receive a first fluid flow and second circuit being configured for receive a second flow of fluid; an external wall (22) surrounding the first circuit and the second circuit; at least one breakable junction portion (30), the breakable portion of junction (30) comprising: a first part (31) connected to the internal heat exchange wall (21) and a second part (32) connected to the outer wall (22), and the mechanical resistance to breakage between the first part (31) and the second part (32) being less than the mechanical resistance to the rupture between the first part (31) and the internal exchange wall thermal (21) and mechanical resistance to breakage between the first part (31) and the second part (32) being less than the resistance mechanical failure between the second part (32) and the outer wall 122)

2. Heat exchanger (1) according to claim 1, wherein the heat exchanger (1) is a counter-heat exchanger fluent.

3. Heat exchanger (1) according to claim 1 or 2, wherein the breakable junction portion (30) has a minimum cross-section between 10% and 70% of the maximum cross-section of the Breakable connecting portion (30), preferably between 20% and 50%.

4. Heat exchanger (1) according to any one of claims 1 to 3, wherein the breakable junction portion (30) has a cross-section minimum between 0.01 mm and 5 mm?

5. Heat exchanger (1) according to any one of claims 1 to 4, wherein a minimum length of the breakable junction portion (30) along a fluid flow direction within the exchanger heat (1) is between 0.1 mm and 5 mm, preferably between 0.3 mm and 3 mm.

6. Heat exchanger (1) according to any one of claims 1 to 5, in which the thickness of the breakable joint portion (30) is between 0.05 mm and 4 mm, preferably between 0.1 mm and 2 mm.

7. Heat exchanger (1) according to any one of claims 1 to 6, comprising a plurality of separable joining parts (30) sen- possibly aligned along a fluid flow direction within the heat exchanger (1).

8. Heat exchanger (1) according to claim 7, wherein the ratio of the length along the direction of fluid flow of a part breakable junction (30) by the distance between two breakable parts of consecutive junctions (30) aligned along the flow direction of fluid content is between 20% and 80%, preferably between 35% and 75%.

9. Turbomachine (101) comprising a heat exchanger (1) according any one of the claims | to 8.

10. Turbomachine (101) according to claim 9, wherein the first circuit is connected to a compressor (104) and the second circuit is connected to a turbine (107).

11. Method of manufacturing a heat exchanger (1) according to one of any of the claims | to 7, including at least one step of Powder bed additive manufacturing.

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