CALODUC FLEXIBLE

Abstract

Heat pipe (10) extending along a longitudinal path (X), forming an internal space (11) hermetically isolated from the external environment and filled with a predefined volume of two-phase working fluid, said heat pipe (10) comprising a profiled body (20) forming a hollow body closed at at least two opposite longitudinal ends, said profiled body (20) comprising a plurality of longitudinal channels (23) extending along the longitudinal path (X) between the two ends of the profiled body (20), each having a cross-section delimited by a bottom formed by a peripheral tubular wall (21) of the profiled body (20), and laterally by two longitudinal walls (22) extending radially inwards from the peripheral tubular wall (21), the longitudinal channels (23) surrounding a central channel (24), the longitudinal channels (23) being open towards the central channel (24),characterized in that the streamlined body (20) comprises one or more flexible portions (30). Figure of the abstract: Figure 5,

Description

Title of the invention: FLEXIBLE HEAT PIPE technical field

[0001] This description relates to a flexible heat pipe. This description also relates to a spacecraft comprising such a flexible heat pipe. Prior art

[0002] During the operation of a spacecraft, such as a satellite, in orbit, a number of onboard electrical and electronic devices dissipate a quantity of heat, an amount indexed to the intrinsic efficiency of these devices and which can be significant for certain high-power devices. In order to maintain the thermal environment of these devices within temperature ranges compatible with their operation and performance, it is necessary to provide a heat transfer device to collect, transport, and then dissipate this heat to a cold source, most often space. Another objective for such a device may be the homogenization of the temperature of a device over a certain area or the sharing of power between different devices in order to maintain a certain temperature level for a set of devices or structures in a cold environment.

[0003] The heat pipe is among the various types of heat transfer devices known for this purpose. A heat pipe generally comprises a rigid metal tube forming a central channel in which working fluid moves in the form of vapor, and longitudinal grooves extending axially and around the central channel, inside the tube, intended to advance the working fluid in the form of liquid by capillary action in a direction opposite to that of the vapor.

[0004] Furthermore, it is known that certain dissipative satellite equipment (antennas, panels) can be mobile, moving from a folded configuration that allows the satellite to be housed in the launch vehicle for placement into orbit, to a deployed configuration once the satellite is in orbit. Also, in some cases, this equipment can be moved regularly, for example, according to the satellite's positioning along its orbit, to provide optimal viewing angles towards certain celestial bodies (for observation missions) or towards cold space. However, the mobility of certain equipment, such as antennas and panels, poses integration challenges for traditional solutions due to their rigid structure.

[0005] Furthermore, current systems have limitations in terms of flexibility and length, which complicates their use in environments where compactness Mass reduction and efficiency are crucial. Increasing heat dissipation requirements in satellites necessitate solutions capable of transporting large amounts of heat over long distances, which is limited by the rigidity of existing systems.

[0006] The inventors sought to improve this situation. Summary

[0007] A heat pipe is proposed, configured for use under low or zero gravity, extending along a longitudinal path, forming an interior space hermetically isolated from the external environment and filled with a predefined volume of two-phase working fluid, said heat pipe comprising a profiled body forming a hollow body closed at at least two opposite longitudinal ends, said profiled body comprising a plurality of longitudinal channels extending along the longitudinal path between the two ends of the profiled body, each having a section delimited by a bottom formed by a peripheral tubular wall of the profiled body, and laterally by two longitudinal walls extending radially inwards from the peripheral tubular wall, the longitudinal channels surrounding a central channel, the longitudinal channels being open in the direction of the central channel.The heat pipe is characterized in that the profiled body comprises one or more flexible portions.

[0008] According to certain advantageous aspects, the heat pipe may include one or more of the following characteristics, taken individually or according to all possible technical combinations.

[0009] The heat pipe may comprise one or more hermetically sealed flexible sheaths. Each flexible portion may be covered by at least one of said one or more flexible sheaths.

[0010] Each longitudinal channel can delimit a free space suitable for the circulation of the working fluid in liquid form by capillary action.

[0011] The profiled body can be obtained, in whole or in part, by extrusion.

[0012] The heat pipe may comprise one or more rigid portions, each portion A flexible portion is arranged between two rigid portions. Each flexible portion can be less rigid than the adjacent rigid portions.

[0013] At least one of said one or more flexible portions may have a helical shape along the longitudinal path.

[0014] At least one of said one or more flexible portions may comprise a plurality of individual elements arranged one after the other along the longitudinal path.

[0015] Each individual element can be articulated with respect to the directly adjacent individual elements.

[0016] The heat pipe can be mobile between a folded configuration and a deployed configuration, the longitudinal path being different between the folded configuration and the deployed configuration.

[0017] According to another aspect, a spacecraft is proposed comprising a body, a deployable appendage movable relative to the body and a heat pipe as described above, in which a first part of the heat pipe is fixed on the body of the spacecraft and a second part of the heat pipe separated from the first part by at least one of said one or more flexible portions is fixed to the deployable appendage. Brief description of the drawings

[0018] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0019] [Fig-1] is a schematic view of a heat pipe according to the present description in a folded configuration.

[0020] [Fig.2] is a schematic view of a heat pipe according to the present description in a configuration deployed.

[0021] [Fig.3] is a schematic view that represents a cross-section of the heat pipe figures 1 and 2.

[0022] [Fig.4] is a schematic view that represents a longitudinal section of a rigid portion of the heat pipe in figures 1 and 2.

[0023] [Fig.5] is a partial schematic view which represents a longitudinal section of the heat pipe of figures 1 and 2 according to a first embodiment.

[0024] [Fig.6] is a schematic view of the heat pipe of Figures 1 and 2 according to a second method of implementation.

[0025] [Fig.7] is a partial schematic view of a first variant of the heat pipe of the figures 1 and 2 according to the second embodiment.

[0026] [Fig.8] is a partial schematic view of a second variant of the heat pipe of the figures 1 and 2 according to the second embodiment.

[0027] [Fig.9] is a partial schematic view of a third variant of the heat pipe of the figures 1 and 2 according to the second embodiment. Description of the implementation methods

[0028] A heat pipe 10 according to the present invention is now described first with reference to Figures 1 to 4.

[0029] The heat pipe 10 extends along a longitudinal path X. In the following description, orientation qualifiers such as "longitudinal" and "radial" are defined, unless otherwise specified, by reference to the longitudinal path X. A radial direction is a direction perpendicular at a given point on the longitudinal path X. Furthermore, unless otherwise specified, the adjectives "interior," "internal," and "external" and "external" are used with reference to a radial direction such that the inner / internal part (i.e. radially inner / internal) of an element is closer to the longitudinal path X than the outer / external part (i.e. radially outer / external) of the same element.

[0030] The heat pipe 10 can be an elongated device along the longitudinal path X. The longitudinal path X can have a length between 0.3 m and 20 m. In other words, the heat pipe 10 can have a length between 0.3 m and 20 m.

[0031] The heat pipe forms an internal space 11 hermetically sealed from the external environment and filled with a predetermined volume of two-phase working fluid. The working fluid can be ammonia, propylene, methanol, water, or any other medium exhibiting liquid-vapor equilibrium under saturated conditions. The pressure of the working fluid in the internal space 11 of the heat pipe 10 can be between 0.01 bar and 100 bar, or even higher.

[0032] The heat pipe 10 comprises a profiled body 20 forming a hollow body closed at at least two opposite longitudinal ends. The heat pipe 10 is capable of extracting heat from a hot source 13 and transferring it to a cold source 14 by means of a two-phase working fluid circulation within the profiled body 20. The hot source 13 may be a heat-dissipating electronic device. The cold source 14, as will be described later, may be space, other heat-transporting equipment, or a heat sink. The profiled body 20 may comprise a first end 20a and a second end 20b, opposite each other along the longitudinal path X. The profiled body 20 may be closed at the first end 20a and the second end 20b, for example, by respective closure elements.

[0033] Particularly visible in Figures 3 and 4, the profiled body 20 comprises a plurality of longitudinal channels 23 extending along the longitudinal path X between the two ends of the profiled body 20. Each longitudinal channel 23 may be parallel to the longitudinal path. Each longitudinal channel 23 has a cross-section delimited by a bottom formed by a peripheral tubular wall 21 of the profiled body 20, and laterally by two longitudinal walls 22 extending radially inward from the peripheral tubular wall 21. The longitudinal channels 23 surround a central channel 24. The longitudinal channels 23 are open in the direction of the central channel 24.

[0034] Each longitudinal channel 23 can be filled with working fluid in liquid form. The central channel 24 can be partially filled with working fluid in liquid form, particularly at the condensation portion 42.

[0035] The heat pipe 10 can be adapted for the movement of the working fluid in vapor form in the central channel 24 and in liquid form in the longitudinal channels 23. The longitudinal channels 23 can form grooves Peripheral longitudinal channels extend along the longitudinal path X between the two opposite ends of the profiled body 20 around the central channel 24, that is, from the first end 20a to the second end 20b of the profiled body 20. As will be seen later, it is possible that one or more longitudinal channels 23 may include one or more segments separated by discontinuities in the tube wall 21 and the side walls 22. The longitudinal channels 23 may be adapted to advance the working fluid in liquid form in a direction opposite to that of the vapor in the central channel 24. The longitudinal channels 23 may be adapted to advance the working fluid in liquid form by capillary action. In this sense, the longitudinal channels 23 may form a capillary network. The longitudinal channels 23 may be distributed annularly, preferably regularly, around the central channel 24.The tubular wall 21 may have an external diameter between 3 mm and 50 mm, preferably between 5 mm and 30 mm.

[0036] At least one or more of said longitudinal channels 23 may have a cross-section normal to the longitudinal path X having a general concavity. More particularly, at least one or more of said longitudinal channels 23 may have a cross-section in the form of a circular arc or an oval arc, a trapezoidal shape, or even a teardrop shape open towards the channel. Each longitudinal channel 23 may delimit a free space adapted to receive the working fluid in liquid form. The free space may be adapted to the circulation of the working fluid in liquid form by capillary action. Each longitudinal channel 23 may have dimensions and / or a shape adapted to the circulation of the working fluid in liquid form by capillary action. By "free space" is understood to mean an area devoid of any solid part or material structure and, in particular, suitable for receiving the working fluid.In particular, each longitudinal channel 23 can be free of porous material. Generally, the heat pipe 10 can be free of porous material for the circulation of the two-phase working fluid, especially sintered (i.e., obtained by a sintering process), in the form of fabric layers or metal film mats. The heat pipe 10 can be free of porous material having a pore size less than or equal to 50 µm. The absence of such porous materials in the longitudinal channels reduces pressure losses and improves fluid flow, increasing heat transfer efficiency.

[0037] Remarkably, the profiled body 20 comprises one or more flexible portions 30. The integration of flexible portions allows adaptation to various configurations of the heat pipe, facilitating installation in constrained environments and optimizing available space. Such a heat pipe 10 is thus suitable for operation in a space environment, being flexible, thermally efficient, and relatively inexpensive to manufacture. The structure of said one or more flexible portions will be described in more detail later.

[0038] By "flexible," it is understood that each flexible portion 30 of the profiled body 20 is adapted to be deformed, bent, curved, or flexed, preferably reversibly, for example under the effect of external forces, in order to modify the longitudinal path X of the heat pipe 10 at the flexible portion 30. In another formulation, each flexible portion 30 may have a degree of flexibility that allows the longitudinal path X of the heat pipe 10 to be modified locally at the flexible portion 30. The term "flexible" refers to the ability of an object to bend, curve, or deform without breaking, thus allowing adjustments in its shape or position. In contrast, a "rigid" object is inflexible and retains its original shape, resisting deformation.

[0039] In this sense, each flexible portion 30 may be less rigid than adjacent portions of the profiled body 20. In distinction, the portions adjacent to each flexible portion 30 may be referred to hereafter as "rigid portions 40". Each flexible portion 30 may therefore be less rigid than the adjacent rigid portions 40 of the profiled body 20. More generally, each of said one or more flexible portions 30 may be less rigid than each of said one or more rigid portions 40. The longitudinal path X may be fixed, i.e., unchangeable, at each rigid portion 40. Each rigid portion 40 may be straight or curved. In this sense, the longitudinal path X of the heat pipe 10 may be straight or curved at each rigid portion 40. The profiled body 20 may comprise one or more rigid portions 40. Each flexible portion 30 may be arranged between two rigid portions 40.The profiled body 20 may comprise an alternating succession of rigid portions 40 and flexible portions 30. Each flexible portion 30 may be structurally independent of the adjacent rigid portions 40. The heat pipe may include connecting elements between each rigid portion 40 and flexible portion 30. A variant is also possible in which each flexible portion 30 may be formed from the same material as the adjacent rigid portions 40. Figure 4 is a longitudinal cross-sectional view of a rigid portion 40 of the heat pipe 10.

[0040] A force greater than a threshold force may be required to modify the longitudinal path X at the level of at least one of said one or more flexible sections 30, and preferably at the level of each of said one or more flexible sections 30. In this sense, the heat pipe 10 is held in position when no force or a small force is applied to it. The internal pressure exerted by the two-phase working fluid can generate the threshold force necessary to adjust the longitudinal path X at the level of at least one of said one or more flexible sections.

[0041] The profiled body 20 therefore includes longitudinal channels 23 at the level of each flexible portion 30. Similarly, the profiled body 20 can include longitudinal channels 23 at the level of each rigid portion 40. In other words, each longitudinal channel 23 extends longitudinally at the level of said one or more flexible portions 30, and where applicable at the level of said one or more rigid portions.

[0042] Each flexible portion 30 can be capable of forming at least one bending angle θ between 0° and 180° inclusive, or even between 0° and 360° inclusive. The longitudinal path thus forms an angle equivalent to the bending angle θ at the flexible portion 30. When said flexible portion 30 forms a bending angle θ of 180°, it can be straight, i.e., the longitudinal path X is straight at the flexible portion 30. When said flexible portion 30 forms a bending angle θ of 0° or 360°, it can have a U-shape. Finally, when said flexible portion 30 forms a bending angle θ between 0° and 180° or between 0° and 360°, for example 90° as shown in [Fig. 2], it can have a bent angle shape. Each flexible portion can be capable of forming several bending angles. In this sense, the flexible portion can have an S-shape, for example.

[0043] The profiled body 20 may include one or more openings 25 in at least one flexible portion 30. Each of these one or more openings 25 may form a discontinuity in one or more longitudinal channels 23. Remarkably, the inventors have found that such openings 25 do not impede the flow of the working fluid in liquid form. Furthermore, each of these one or more openings may form a circumferential channel that connects all or part of the longitudinal channels 23 with fluid. In this sense, these one or more openings 25 can ensure a uniform distribution of the pressure of the working fluid in liquid form within the longitudinal channels. In other words, each of these one or more openings 25 has a pooling and sharing function for the liquid supply, providing the longitudinal channel 23 with the greatest demand for liquid from the others.The flexible portion 30 may have one or more openings 25 when the bending angle 0 is different from 180°, and preferably at the part having the largest radius of curvature to form the bending angle 0. The external sealing of the heat pipe having such openings can be achieved by a sheath 50 which covers the flexible portion 30. Such a sheath is described in more detail later.

[0044] The heat pipe can be movable between a folded CR configuration and an deployed CD configuration. The longitudinal path X can differ between the folded CR configuration and the deployed CD configuration. The longitudinal path X can be straight or curved in the folded CR configuration. Similarly, the longitudinal path X can be straight or curved in the deployed CD configuration. Regardless of the configuration of the heat pipe 10, the longitudinal path X can be straight or form one or more bends. Furthermore, the longitudinal path X can be planar or three-dimensional, regardless of the configuration of the heat pipe 10.

[0045] The heat pipe 10 may have a reduced footprint in the folded configuration CR compared to the extended configuration CD. In this sense, the heat pipe 10 may be more compact when folded than when extended. At least one bend angle 0 of one or more of said flexible portions 30 may be smaller in the folded configuration CR than in the extended configuration CD.

[0046] The hot source 13 may be in contact with an evaporation portion 41 of the profiled body 20. The evaporation portion 41 may coincide with a first rigid portion 40 among said one or more rigid portions 40. Also, the evaporation portion 41 may be arranged at the first end 20a of the heat pipe 10 along the longitudinal path X. The cold source 14 may be in contact with a condensation portion 42 of the profiled body 20. The condensation portion 42 may coincide with a second rigid portion 40 among said one or more rigid portions 40. The condensation portion 42 may be arranged at the second end 20b of the heat pipe 10 along the longitudinal path X.

[0047] In the example shown in Figures 1 and 2, the profiled body 20 comprises a single flexible portion 30 arranged between a rigid portion 40 corresponding to the evaporation portion 41 and another rigid portion 40 corresponding to the condensation portion 42. The heat pipe 10 therefore has a bent shape, such as an L or a V. However, it is possible for the profiled body 20 to comprise several (two or more) flexible portions 30. Thus, the heat pipe 10 may, for example, have a Z-shaped conformation.

[0048] The heat pipe 10 is configured for use in low or zero gravity, for example, in space. For instance, the heat pipe 10 can be configured for use in a spacecraft or device sent into space. In particular, this could be a satellite for telecommunications, surveillance, or other functions. The heat pipe 10 can be used in total weightlessness or in a low or moderate gravity situation, for example, on the surface of a celestial body such as the Moon or Mars. The heat pipe 10 can be used with zero or very low external pressure, or even at atmospheric pressure. In general, the heat pipe can be used regardless of the external pressure.

[0049] The heat pipe 10, due to its flexibility, is suitable for use in a spacecraft (e.g., a satellite) comprising a deployable appendage, where a first part of the heat pipe 10 (e.g., a first rigid portion 40) is fixed to the body of the spacecraft and a second part of the heat pipe 10 (e.g., a second rigid portion 40) separated from the first part by at least one of said one or more flexible portions 30, is fixed to the deployable appendage.

[0050] One advantage of the heat pipe's flexibility is that it facilitates its integration into a spacecraft. It allows it to be connected to two parts to be thermally connected (panels or equipment), while also offering the possibility of moving these parts relative to each other.

[0051] The flexibility of the heat pipe 10 also reduces the constraints related to manufacturing tolerances when connecting it to other components. Thanks to its flexibility, the heat pipe adapts to variations in the relative positions of the parts to be thermally connected. The heat pipe can be connected to various components without requiring extreme precision in the alignment or adjustment of these components. In other words, this flexibility makes it possible to compensate for dimensional deviations and imperfections, thus facilitating integration into complex systems. The flexibility of the heat pipe also makes it possible to connect a heat pipe of standard dimensions to components whose relative position may vary from one system to another. This characteristic is particularly advantageous in technological fields where the configuration of each system is unique, such as in the space sector where each satellite is generally manufactured individually.

[0052] As a result, the assembly process becomes more efficient and less costly, while maintaining optimal thermal system performance. Such an assembly process can be called "MAIT" for spacecraft, for "Manufacturing, Assembly, Integration, and Testing"—it is a process where the components of a satellite are manufactured, assembled, integrated into a functional system, and then rigorously tested to validate their performance and reliability before launch.

[0053] The heat pipe 10 may include one or more flexible, airtight sheaths 50. Each flexible portion 30 may be hermetically sealed by at least one of said one or more flexible sheaths 50. The heat pipe can therefore be sealed at each flexible portion by said one or more sheaths 50. The sheath 50 may be configured to prevent any leakage of working fluid to the outside.

[0054] It is possible for a space or gap to exist between the sheath and the profiled body of the heat pipe. This space may be suitable for allowing some freedom of movement of the profiled body within the sheath, without compromising the seal. Furthermore, this space may receive working fluid passing through the openings 25, allowing for uniform distribution of the fluid and thus improving the efficiency of heat transfer. Alternatively, each sheath 50 may closely cover the profiled body 20, or even be clamped onto the profiled body 20. In other words, each flexible portion 30 may extending inside one or more of the said flexible sheaths 50. This ensures the sealing and hermetic insulation of the internal space 11 to the outside of the heat pipe 10 at the level of each flexible section 30.

[0055] Preferably, the heat pipe 10 may include a flexible sheath 50 associated with each flexible portion 30. In this sense, each flexible portion 30 may be covered by a respective flexible sheath 50 from among said one or more flexible sheaths 50. Each sheath 50 may be fixed on either side to the adjacent rigid portions 40 of the associated flexible portion 30. This fixing may be effected by welding, via a fixing sleeve. The heat pipe 10 may therefore include several structurally distinct flexible sheaths 50, preferably in a number equal to the number of flexible portions 30. Alternatively, one or more of said flexible sheaths 50 may cover several of said one or more flexible portions 30. In this case, the single-piece flexible sheath 50 may cover the rigid portions 40 located between the flexible portions covered by this sheath.

[0056] Each flexible sheath 50 can be particularly airtight with the two-phase working fluid, in liquid and vapor form. Each flexible sheath 50 can be made of polymer, for example PTFE, or of corrugated metal, for example stainless steel, titanium, or aluminum.

[0057] The profiled body 20 can be obtained, in whole or in part, by extrusion. Extrusion can be the main manufacturing operation. Using a press, an aluminum alloy is forced through a die having the desired shape to obtain the profiled body 20 at the die's exit. Generally, the profiled body 20 can be metallic, particularly aluminum. In particular, each of said one or more rigid portions 40 can be obtained by extrusion. Extrusion manufacturing of the profiled body ensures precise and economical production, enhancing structural robustness. Alternatively, the profiled body 20 can be obtained, in whole or in part, by an additive manufacturing process, or by conventional manufacturing and assembly techniques such as machining or electrical discharge machining (EDM) for fabrication and welding or brazing for assembly.

[0058] A first embodiment of the heat pipe 10 is now described with reference to [Fig.5].

[0059] In the first embodiment, at least one or more of said flexible portions 30 may have a helical or spiral shape along the longitudinal path X. In this sense, said flexible portion 30 may comprise a plurality of successive turns along the longitudinal path X. The helical shape confers flexibility to the flexible portion 30. Preferably, each flexible portion 30 may have such a helical shape. To achieve this, the profiled body 20 may to include a through helical slot 33. Such a slot 33 can be obtained by machining in the profiled body 20, for example obtained by extrusion. Such a helical slot 33 can be obtained by machining.

[0060] The slot 33 can form one or more openings 25. Each turn of the slot 33 can form all or part of one of the openings 25. In this sense, each turn of the slot 33 can form a circumferential channel that connects all or part of the longitudinal channels 23 to the fluid. In a particular case, the slot 33 can form a single helical opening 25. The slot 33 can be adapted to advance the working fluid in liquid form in a direction opposite to that of the vapor in the central channel 24. Advantageously, the helical shape of the flexible portions offers increased flexibility, allowing for easier adjustments in confined spaces, and also contributes to better fluid circulation, leading to increased heat transfer efficiency, thereby increasing the overall performance of the heat pipe.

[0061] The helical flexible portion 30 may have a length 11 between 0.1 and 10 m. The helical slot 33 may have a pitch 12 between 0.1 mm and 100 mm. The helical slot 33 may have a width 13 between 0.1 mm and 5 mm. The helical slot 33 may form an angle α between 90° (exclusive) and 0° (exclusive) with respect to the longitudinal path, preferably between 45° (inclusive) and 0° (exclusive). The parameters listed above may, in particular, be considered in a rectilinear configuration of the flexible portion 30 (i.e., for a longitudinal path X forming a straight line segment at the level of the flexible portion 30). The dimensions of the helical slot 33, with a pitch 12 varying between 0.1 mm and 100 mm, a width 13 ranging from 0.1 mm to 5 mm, and an angle between 0° and 90° excluded, offer optimal flexibility to the flexible portion 30.These values ​​allow for a flexibility in the flexible portion that meets the specific needs of integration in complex environments where space is limited.

[0062] Each of said one or more flexible portions 30 may be a single piece. Each of said one or more flexible portions 30 may be obtained by machining an extrusion profile. In a particular case, the profile body 20 may be a single piece. In this sense, the profile body 20 may be entirely obtained by extrusion, each of said one or more flexible portions 30 being formed, for example by machining, from the profile body 20 obtained by extrusion.

[0063] In what follows, a second embodiment of the heat pipe 10 is described with reference to figures 6 to 9.

[0064] In the second embodiment, at least one of said one or more flexible portions 30 may comprise a plurality of individual elements 31 arranged one after the other along the longitudinal path X. Such Segmentation confers flexibility to the flexible portion 30. It is understood that each individual element 31 therefore has a tubular shape. Each individual element 31 comprises a segment of each longitudinal channel 23. The heat pipe can have at least one configuration in which each individual element is in fluidic communication (i.e., in hydraulic connection) with the directly adjacent individual elements via at least one longitudinal channel 23.

[0065] According to a first embodiment shown in Figures 6, 8, and 9, each individual element 31 can be articulated relative to the directly adjacent individual elements 31. The use of articulated individual elements allows for additional mobility and adaptability, facilitating the adjustment of the heat pipe. Each individual element can have a mechanical connection relative to the directly adjacent individual elements.

[0066] Two adjacent individual elements 31 can be articulated relative to each other by complementary shape. In other words, two adjacent individual elements 31 can comprise complementary reliefs 32a; 32b adapted to articulate the adjacent individual elements 31 relative to each other. For this purpose, each individual element 31 can comprise such reliefs longitudinally on each side. Said complementary reliefs 32a; 32b can comprise a male relief 32a and a female relief 32b cooperating with each other, for example by interlocking. Thus, two adjacent individual elements 31 can respectively comprise a male relief 32a and a female relief 32b cooperating with each other so as to form a pivoting joint between the two adjacent individual elements 31. Each individual element 31 can comprise a male relief 32a and a female relief 32b, preferably longitudinally opposed.The set of individual elements 31 may be identical. Alternatively, the plurality of individual elements 31 may comprise an alternating succession of individual elements 31 of a first type and individual elements 31 of a second type, where each individual element 31 of the first type comprises two male reliefs 32a and where each individual element 31 of the second type comprises two female reliefs 32b.

[0067] Each individual element 31 can be pivotally articulated about at least one radial axis (i.e., perpendicular to the longitudinal path X) relative to directly adjacent individual elements 31. Each individual element 31 can be pivotally articulated by means of a ball joint or spherical joint relative to directly adjacent individual elements 31.

[0068] The plurality of individual elements 31 may include two individual end elements 31 which are opposed along the longitudinal path X and which cooperate in a fixed or articulated manner with a portion (for example a rigid portion 40) of the profiled body 20, adjacent to the flexible portion 30.

[0069] The complementary reliefs 32a; 32b between two adjacent individual elements 31 can be adapted to limit, or even block, a translational displacement of one of the individual elements 31 relative to the other along the longitudinal path X. Alternatively or additionally, the complementary reliefs 32a; 32b between two adjacent individual elements 31 can be adapted to limit, or even block, a rotation of one of the individual elements 31 relative to the other about an axis coinciding with the longitudinal path X locally at the level of the individual element considered, in particular to keep the longitudinal channels aligned between the two individual elements. For example, for this purpose, one of the two adjacent individual elements 31 may include a lug extending radially outwards and which is received in a hole formed in the other of the two individual elements 31.

[0070] In a second embodiment shown in Figures 6 and 7, the individual elements 31 can be structurally independent of each other. The plurality of individual elements 31 can be contained within the flexible sheath 50 covering the flexible portion 30 so as to maintain the continuity of individual elements 31 one after the other along the longitudinal path X.

[0071] The individual elements 31 can be monobloc. Furthermore, all or part of the individual elements 31 can be obtained by additive manufacturing.

Claims

Demands

1. A heat pipe (10) configured for use under low or zero gravity, extending along a longitudinal path (X), forming an internal space (11) hermetically sealed from the external environment and filled with a predefined volume of two-phase working fluid, said heat pipe (10) comprising a profiled body (20) forming a hollow body closed at at least two opposite longitudinal ends, said profiled body (20) comprising a plurality of longitudinal channels (23) extending along the longitudinal path (X) between the two ends of the profiled body (20), each having a cross-section delimited by a bottom formed by a peripheral tubular wall (21) of the profiled body (20), and laterally by two longitudinal walls (22) extending radially inward from the peripheral tubular wall (21), the longitudinal channels (23) surrounding a central channel (24), the longitudinal channels (23) being open at central canal direction (24),characterized in that the profiled body (20) comprises one or more flexible portions (30).

2. Heat pipe (10) according to the preceding claim, wherein comprising one or more hermetically sealed flexible sheaths (50), and in which each flexible portion (30) is covered by at least one of said one or more flexible sheaths (50).

3. Heat pipe (10) according to any one of the preceding claims, wherein each longitudinal channel (23) delimits a free space adapted to the circulation of the working fluid in liquid form by capillary action.

4. Heat pipe (10) according to any one of the preceding claims, wherein the profiled body (20) is obtained, in whole or in part, by extrusion.

5. Heat pipe (10) according to any one of the preceding claims, wherein it comprises one or more rigid portions (40), each flexible portion (30) being arranged between two rigid portions (40), and wherein each flexible portion (30) is less rigid than the adjacent rigid portions (40).

6. Heat pipe (10) according to any one of the preceding claims, wherein at least one of said one or more portions flexible (30) has a helical shape along the longitudinal path (X).

7. Heat pipe (10) according to any one of claims 1 to 4, wherein at least one of said one or more flexible portions (30) comprises a plurality of individual elements (31) arranged one after the other along the longitudinal path (X).

8. Heat pipe (10) according to the preceding claim, wherein each individual element (31) is articulated with respect to the directly adjacent individual elements (31).

9. Heat pipe (10) according to any one of the preceding claims, which is movable between a folded configuration (CR) and a deployed configuration (CD), the longitudinal path (X) being different between the folded configuration (CR) and the deployed configuration (CD).

10. A spacecraft comprising a body, a deployable appendage movable relative to the body and a heat pipe (10) according to any one of the preceding claims, wherein a first part of the heat pipe (10) is fixed to the body of the spacecraft and a second part of the heat pipe (10) separated from the first part by at least one of said one or more flexible portions (30) is fixed to the deployable appendage.

Images