EP2861928A1

EP2861928A1 - Temperature control device

Info

Publication number: EP2861928A1
Application number: EP13739684.2A
Authority: EP
Inventors: Christophe Figus
Original assignee: Airbus Defence and Space SAS
Current assignee: Airbus Defence and Space SAS
Priority date: 2012-07-18
Filing date: 2013-07-18
Publication date: 2015-04-22
Anticipated expiration: 2033-07-18
Also published as: ES2659748T3; EP2861928B8; WO2014013035A1; EP2861928B1; FR2993649A1; FR2993649B1

Abstract

The invention relates to a heat exchange and transfer device that consists of a closed cavity containing a biphasic fluid and includes: at least one heat exchange area comprising a flat chamber configured in the shape of a space, the size of which is significantly smaller than the other two, typically at least ten times smaller, said flat chamber having a first capillary structure on all or part of the inner surface thereof, enabling the fluid in the liquid form thereof to wet said first capillary structure, at least one heat transport area configured in the shape of at least one tube having a second capillary structure over all or part of the inner face thereof, said flat chamber and said at least one tube being connected such that the vapor can circulate freely in the entire cavity, and that capillarity continuity is ensured between the first and second capillary structures so that the liquid can wet the entire resulting capillary structure.

Description

THERMAL CONTROL DEVICE

The present invention relates to the field of thermal control devices.

It relates more particularly to a thermal control device using a two-phase thermal enclosure (heat pipe).

Preamble and prior art

By thermal control is meant maintaining a given equipment at a temperature within a predetermined range. The heat produced by one or more heat sources must be collected and transported to areas where it can escape into heat sinks (radiators).

Such a requirement is particularly critical for electronic equipment embedded on satellite. Indeed, said equipment is highly dissipative and must be maintained in a given temperature range despite significant variations in the thermal environment of the satellite and an inability to evacuate heat by natural or forced convection.

For example, within a satellite coexist radiative walls said radiator panels, or radiators, which dissipate heat by radiation to the cold space, and walls carrying the dissipative electronic equipment, said equipment panels. The heat dissipated by the equipment is collected at the equipment door panels and must be evacuated to the radiator panels.

It is understood that the thermal coupling between equipment panels and radiator panels is critical to ensure the proper evacuation of the heat dissipated by the electronic equipment. This thermal coupling is also complex to achieve because of the limited space available within the satellite, related to the size of the equipment and their geometry. Furthermore, the thermal control system must meet conflicting needs, because it must both ensure efficient collection of the heat produced by the dissipative equipment, and allow efficient thermal transport over a potentially large distance between the door panels. equipment and panels radiators.

Heat pipes are conventionally used to provide the thermal transport function.

It is recalled that a heat pipe uses the phase change of a fluid to ensure the collection of heat in a hot place, and its transfer as a vapor to a cold place. A tubular heat pipe is conventionally composed of a closed tube in which the liquid and gaseous phases of the same fluid maintained under pressure coexist. The heat pipe makes it possible to store the heat by evaporation and to restore it by condensation of the fluid.

A first part of the heat pipe, called hot zone (evaporator), is, for this purpose, disposed in the vicinity of a heat source, such as for example a dissipative element of thermal energy. At this point, the liquid contained in the heat pipe vaporizes by absorbing heat. The steam thus created propagates inside the heat pipe to another part of the heat pipe, called cold zone (condenser), disposed in the vicinity of a heat sink. The gas then condenses by returning the previously absorbed heat. The necessary circulation of the liquid between the cold zone and the hot zone is commonly done by capillarity, which is facilitated by the use of grooves, lattices, arteries or metal foam disposed on the inner surface of the heat pipe.

A heat source is typically an equipment or equipment panel. A typical heat sink is a radiator panel.

A heat pipe can be in thermal contact with several heat sources and several heat sinks.

The conduit of a tubular heat pipe (see Figures 1a and 1b) is a cylindrical tube whose inner wall is grooved, for example by extrusion, thereby creating the capillary structure through which the liquid passes. A soleplate, contiguous to the tube heat pipe over a part of its length, promotes thermal contact between the tubular heat pipe and heat sources and / or heat sinks, through a flat mounting interface. The typical length of a tubular heat pipe embedded on a satellite for cooling panels is from a meter to a few meters and its diameter from one to a few centimeters. In the case of an application considered here, the heat produced by the equipment mounted on a satellite panel must be transported to another panel of the satellite, or to another part of the same panel (it is also possible to have a heat pipe which spreads over the radiator heat by doing at the same time interface with one or more dissipative equipment), where it will be dissipated.

This is the case for example when the equipment carrier panel is in the sun (it radiates less and therefore evacuates heat less well) and another panel is in the shade (favorable case for radiating heat). In this case, the tubular heat pipes can be extended so that they carry the heat from one panel to the other (they are bent at the intersection). The heat is effectively removed when at least one of the two panels is in the shade (or at low solar incidence).

In the case of the thermal control of equipment panels on board satellites, the collection of heat at the level of equipment is done by heat exchange between a number of tubular heat pipes and the equipment.

In this case, the main limitation observed is the heat collection capacity by the heat pipes for a given heat flow density. With a given heat pipe profile, the number of heat pipes to be positioned is sized by the heat collection and in this case, the heat pipe network is oversized for the heat transport from one panel to another and / or the diffusion of heat. heat on a panel, resulting in a large surplus of mass.

On the other hand, the performance of the heat exchange at the heat pipe is proportional to the heat exchange surface internal to the heat pipe (grooves for example) and therefore to minimize the thermal gradients it is sometimes necessary to multiply the number of heat pipes. Presentation of the invention

The invention is aimed primarily at a heat exchange and transfer device consisting of a closed cavity containing a two-phase fluid, said device comprising: at least one heat exchange zone comprising a flat enclosure configured in the form of a volume whose dimension is considerably smaller than the other two, typically at least ten times smaller, said flat enclosure having a first capillary structure on all or part of its inner surface, allowing the fluid in its liquid form to wet said first capillary structure,

at least one heat transport zone configured in the form of at least one tube (and more generally of several tubes) having a second capillary structure on all or part of its internal face, and

said flat enclosure and said at least one tube being connected so that the vapor can circulate freely throughout the cavity, and that continuity of capillarity is ensured between the first and second capillary structures so that the liquid can wet the entire capillary structure thus formed.

In other words, it is a thermal regulation device implementing a thermal enclosure containing a two-phase fluid, said device comprising:

at least one heat exchange zone comprising a heat pipe configured in the form of a thin envelope (that is to say a large exchange surface with a very small thickness, typically at least ten times smaller, than the other dimensions), said exchange zone being said "flat enclosure" (which can be in the form of a plate in one, two or three dimensions),

at least one heat transport zone configured in the form of at least one tubular heat pipe, said tubular heat pipe being called a "tube", and

at least one connection node between the flat enclosure and the tube, said connection node having a continuity of capillarity between the flat enclosure and the tube.

The capillary dimension of the grooves, pores, cells, lattices, etc. which ensure the flow of the fluid in liquid form through the node is of substantially the same size (in a ratio of 0.5 to 2) as the capillary dimension of the tubular heat pipe. Advantageously, in the case of several tubes connected to the same flat enclosure, said tubes have steam ducts whose sum of the passage sections is substantially equal to the vapor passage section of said flat enclosure, in order to facilitate the flow of steam between the flat enclosure and the tubes.

It is understood that the device of the invention independently solves the dimensioning suitable for heat transport, and the dimensioning adapted to the heat exchange, with a single system. The device uses on the one hand a tubular heat pipe (tube) without heat exchange function for the heat transport function, this tubular heat pipe being of small dimensions, and capable of accepting a geometry dictated by the arrangement and the geometry spaces left free between equipment panels and radiators.

On the other hand, the device uses an extended cavity heat pipe, here called flat enclosure, disposed under the electronic equipment, for the heat exchange function.

The device comprises a capillary connection between the at least one tube and the flat enclosure to ensure the continuity of fluid circulation by capillarity between its hot end and its cold end.

The invention thus reduces the mass of the heat collection and transport system compared to a conventional heat pipe system. It also has the advantage of enabling better thermal coupling between equipment panels and radiators.

A secondary problem that is solved by the invention is to be more efficient for non-planar dissipative wall equipment.

According to a particular embodiment, the heat transport zone comprises an area of increased deformability in at least one predetermined direction. By deformable zone is meant a zone of low rigidity under the environmental conditions in which the device is supposed to operate. In this way, it is possible to accommodate deformations occurring between the supports of the ends of the device without practically exerting efforts on these supports. In the particular case of ends arranged one on an equipment panel and the other on a radiator, this deformability of the transport zone makes it possible to accommodate the deformations, for example thermal, without risking breaking the control device. thermal shearing.

In a particular embodiment adapted to the case of two supports of the ends of the device arranged in different planes, the tube comprises several bends arranged in different planes.

The device then comprises two substantially flat flat enclosures located in different planes, connected by a tube having two torsion zones, said torsion zones being disposed in at least two different planes, said planes being respectively the planes in which are arranged the flat speakers

In this way, the rigidity of the tube is significantly reduced in two planes, allowing accommodation of a small displacement or angular deformation occurring between these two planes.

In a particular case of implementation, corresponding to the case of a form heat source or well having a plurality of planes, for example at least two planar walls of dissipative equipment, the flat enclosure has a shape comprising at least two substantially flat areas extending in two distinct planes and connected by an edge.

Regardless of these particular embodiments, it is advantageous for the thickness of the flat enclosure to be substantially equal to the diameter of the tube.

In another case of implementation, corresponding to the case of a cylindrical source, part of the outer surface of the flat enclosure has a locally cylindrical shape. In a particular embodiment, the flat enclosure and at least one tube are made of the same material, for example invar. The invention also relates to an application of a device, as described, to the cooling of an electronic equipment carrying panel, characterized in that at least a first flat enclosure of said device is attached to at least one thermally skin conductor of the wall, and the heat collected by said at least a first flat enclosure is evacuated, by at least one transport tube, to at least a second flat enclosure disposed in thermal contact with a heat sink, such as a radiator.

The invention aims in another aspect an instrument or a satellite having a heat transfer device as described.

Presentation of figures

The characteristics and advantages of the invention will be better appreciated thanks to the description which follows, description which sets out the characteristics of the invention through a non-limiting example of application.

The description is based on the appended figures which represent:

FIGS. 1 a and 1 b (already cited): views in longitudinal and transverse section of a heat pipe according to the prior art,

FIG. 2: a schematic perspective view of a heat transfer device according to one embodiment of the invention,

FIGS. 3a to 3f: detailed views of the device of FIG. 2,

4: a view of a variant heat transfer device, adapted to the case of dissipative equipment disposed on two perpendicular planes,

FIGS. 5a to 5c: views of an alternative heat transfer device, adapted to the case of dissipative equipment of substantially cylindrical shape,

FIG. 6: a perspective view of another variant of the device,

FIG. 7: a view of another variant of the device, in the case of several flat exchange zones, FIG. 8: a view of the device of FIG. 7, adapted to the case of two dissipative equipments,

FIG. 9: a view of another variant of the device, using a transport zone provided locally with a cooling soleplate,

FIG. 10: a view of a variant of the device, comprising an exchange zone, and several heat transport zones,

Figure 1 1: a perspective view of a variant adapted to the case of equipment arranged on two different planes,

Figure 12: a view of another variant device, in this case.

Detailed description of an embodiment of the invention

It is noted first of all that the figures are not to scale.

The invention described here, in an exemplary non-limiting implementation, finds its place in the context of an on-board thermal control system aboard a vehicle placed in weightlessness, here a satellite. This thermal control system is designed and sized according to the equipment onboard the satellite. Its geometry therefore depends on the geometry of the onboard equipment, and their arrangement within said satellite.

In one embodiment given here by way of illustration and in no way limiting, the heat transfer device consists of a thermal chamber containing a two-phase fluid, this chamber having an internal cavity where the fluid can flow freely in the vapor state. and a capillary structure adapted to retain the fluid in the liquid state.

More specifically (see Figure 2), the device comprises at least one flat enclosure 1 containing a fluid in the two-phase state and forming a heat exchange zone with a heat source or with a heat sink. An enclosure is considered to be flat, of which in each point one of the dimensions is substantially smaller than the other two dimensions, for example ten times smaller. In the present embodiment, the enclosure is rectangular and flat. This flat chamber 1 has a capillary structure on all or part of its inner surface at the place where the heat exchange takes place with the heat source or the heat sink. In the example according to the invention, this capillary structure has a wetted surface extended in at least two directions and capable of exchanging a dense heat flow.

Throughout the rest of the description, the so-called "flat enclosure" will be called such a two-phase heat exchange enclosure containing an internal capillary structure facing the heat exchange zone.

In a non-limiting example illustrated in Figure 2, a flat shape of the flat enclosure 1 is adapted to be in contact with the flat surface of a device or a radiative panel. The surface of the flat enclosure 1 is, in this example, from a few tens to a few hundred square centimeters of surface, for a thickness of a few tenths of a millimeter to a few millimeters.

The advantage provided by this type of flat enclosure 1 is to be able to have a very wide heat exchange surface with a heat source or a heat sink. Several heat sources or heat sinks can advantageously be mounted in thermal contact with the surface of the enclosure.

The device comprises secondly at least one element of substantially tubular shape, called tube 2, more specifically called "transport tube", its length being significantly larger than the largest dimension of its section.

The tube 2 is secured to the flat chamber 1 at a connection point 3. The tube 2 according to the invention has a capillary structure on its inner wall, such as that of a tubular heat pipe as described above. high and considered known in itself. In the device according to the invention, the function of such a tube is essentially to transport as efficiently as possible the heat collected by the flat enclosure 1.

Throughout the remainder of the description, the term "tube" or "transport tube" will be referred to as such a heat transport tube having a structure internal capillary, this capillary structure for combining the transport of the two-phase fluid both in the form of vapor and in the form of liquid in both directions.

In the case of an application to the cooling of dissipative equipments aboard a satellite, the typical length of such a tube 2 can be from a few tens of centimeters to a few meters, and its diameter from one to a few centimeters.

Each transport tube 2 has a significantly smaller section (from 1, 5 to several tens of times less) than the largest section of the flat enclosure (the sections being considered in section along the same plane).

The section of the transport tubes 2 is optimized to transport the heat flux exchanged at the level of the flat enclosure 1.

It is important to note that in Figure 2, only a portion of the tube is visible because it is presented in section at one end. The tube 2 necessarily extends to at least one other heat exchange zone to which it is connected, this other zone being connected either to a heat sink if the chamber 1 is in heat exchange with a heat source, or to a source of heat if the chamber 1 is in heat exchange with a heat sink. Other figures will show a complete system using the device.

Top and sectional views of this device (see FIGS. 3a to 3f) illustrate the arrangement of the various parts of the enclosure 1 and the tube 2.

As illustrated in FIG. 3c, the vapor duct 6 of the tube 2 and the steam duct 5a, 5b, 5c of the flat enclosure 1 communicate with each other, so that there is continuity of flow by inertia of the fluid in vapor form in both directions between the flat chamber 1 and the tube 2 at their point of connection 3. It is not necessary to have a perfect continuity of the geometry of the steam ducts at the level of link point 3, but it must at least be ensured that there is no significant loss of load at this level.

On the other hand, the device is such that there is continuity of capillarity between the capillary structure 7 of the tube 2 and the capillary structure 8 of the flat enclosure 1 at the connection point 3. This capillary continuity must allow the liquid of flow by capillarity in both directions between the flat chamber 1 and the tube 2.

It is recalled that a capillary zone is a geometrically small area where the surface tension effects are predominant over the effects of gravity or inertia. A basic zone of capillarity consists for example of a pore within a porous material, or of a groove in the mass of an inner wall of a tube.

It is not necessary to have a perfect capillary continuity between the capillary structures of the flat enclosure 1 and the tube 2, but at least it must be ensured that there is not a discontinuity of the effect of capillarity at this level. Typically, any discontinuity between the capillary structure of the flat enclosure 1 and that of the tube 2 must not exceed in size the typical dimension of a capillary elementary area, such as a pore and / or a groove, of said capillary structures.

The capillary continuity provided at the connection nodes thus enables the fluid in the liquid phase to flow by capillarity, in an area where the surface tension effects are predominant over gravity or inertia effects.

In a particular case of implementation, given here by way of non-limiting example, the capillary structure 7 of the tubes 2 consists of grooves (FIG. 3d) and the capillary structure 8 of the flat enclosure 1 consists of a porous structure or a porous material (Figure 3c), which has a high permeability. In the case where the flat chamber 1 and the tube 2 are made of the same material (aluminum in the most common case), the pore diameter of the porous structure or of the porous material is then chosen such that it is not greater than twice the opening of the grooves of the capillary structure of the tube 2, in order to facilitate the flow of the liquid by capillarity in both directions. This value may change depending on the wettability characteristics of the fluid in the case where different materials are used.

In the same way, in the case of a tube 2 whose capillary structure consists of a porous structure or of a porous material, it is advantageous for this capillary structure of the tube 2 to be arranged in capillary continuity with the capillary structure. of the flat enclosure 1, also consisting of a porous structure or a porous material, which has a high permeability with a pore diameter that is not greater than the pore diameter of the porous structure or the porous material of the heat pipes. This value can also change depending on the wettability characteristics of the fluid on the different materials used.

In an alternative embodiment, the two-phase capillary exchanger 1 and the transport heat pipe 2 are made in invar, instead of aluminum as used in the prior art. Invar provides the device with greater dimensional stability than aluminum which is advantageous in some applications.

The device which has just been described is able to efficiently collect a dense heat flux emitted by a heat source, and to transport it efficiently towards a remote dissipation zone.

In alternative embodiments, the flat enclosure 1 sees its shape adapted to a non-planar contact surface or in several planes with dissipative equipment.

In this case, the wet surface of the flat enclosure 1 matches the shape of the heat source or heat sink with which it is in contact. If this source or well has a parallelepipedal shape (such as electronic equipment in the case of a heat source), the flat enclosure 1 may have a flat surface conforming to the footprint of the equipment when it is attached to its body. installation plan.

In another case, corresponding to a flat enclosure 1 in contact with several planes of the equipment, the flat enclosure 1 consists of two parts 1 1, 12 planes and perpendicular (see Figure 4) connected so that it there is continuity of their steam ducts and their capillary structures. The connection between the two parts 1 1, 12 of the planar chamber and the tube 2 takes place at the intersection angle of the two parts 1 1, 12 with continuity of the steam ducts and capillary structures as previously described. Again, only a portion of the tube 2 is shown, which necessarily extends in a complete thermal control system to another heat exchanger to which it is connected. If the heat source has a substantially cylindrical shape, such as an electric motor for example, the flat enclosure 1 has a locally toric shape surrounding said source (Figures 5a to 5c).

This diversity of form of flat speakers 1 (plane, multi-plane, toric, etc.) can be advantageously manufactured thanks to rapid manufacturing means, in particular based on powders, for example by additive fusion (three-dimensional direct printing). One can then manufacture in a single step all of the flat enclosure 1, namely the walls of the enclosure and the capillary structure. The transport tube 2 may be a "standard" heat pipe tube welded to the part thus manufactured. It can also be manufactured at the same time as the flat speaker thanks to the rapid manufacturing means. The filling of the device is done according to the state of the art of heat pipe using for example a filling tube (sometimes called "queusot") which can be connected to either a flat speaker or a transport tube, the device .

The transport tube 2 of the device can be optimized for carrying out the heat transport function and only this. Such heat pipes are made cheaply.

In an alternative embodiment of the device, a flat heat exchange chamber 1 may be connected to a plurality of transport tubes 2, 2 ', 2 "(two tubes as in FIGS. 7, 8, 11, 12, three tubes as shown in FIG. in Figures 6 and 10) connected thereto according to the embodiment previously described.

In another variant (FIG. 7), the device comprises a plurality of flat enclosures 1, 1 'connected to one another by at least one transport tube 2, the shape of each flat enclosure 1 possibly being adapted to the heat source or to the well. of heat with which she is in contact.

In this same embodiment, at least two flat speakers 1, 1 ', each flat chamber 1 of the device is in contact with either a heat source 3 or a heat sink 4 (Figure 8). The transport tube 2 connecting the flat speakers 1 to each other is sized to allow efficient heat transport from the heat source 3 to the well In the case where the tube 2 does not itself participate in the heat exchange, it is advantageously dimensioned only for this heat transport function.

Figures 7 and 8 and have a thermal control system consisting of two flat speakers 1, 1 'connected to a tube 2 according to the embodiment described above. The assembly consisting of two enclosures and the tube forms a sealed cavity in which circulates a two-phase fluid for simultaneously performing heat exchange and efficient heat transport.

In some parts of the device, the collection and evacuation of heat can be carried out with the means of the state of the art, for example by means of a sole 13 placed around the transport tube 2 so this soleplate is in thermal contact with a heat source or a heat sink (Figure 9). In this case, the tube 2 serves both as a transport tube and as a heat exchanger, which can be advantageous when the heat source (or heat sink) in contact with the sole of the tube 2 is of large size.

FIGS. 11 and 12 illustrate other embodiments of the device, in which the transport tube 2 is curved and connects two heat exchange zones (here two flat speakers 1, 1 ') whose surfaces are located in different planes . In the case of FIG. 12, the transport tube 2 has several elbows 14, 15 situated in different planes, which gives it a significantly increased deformability in at least one direction, in a predetermined zone, making it possible to accommodate small displacement or angular deformation between the support planes the two-phase capillary exchangers 1, 1 '.

An advantageous application of the device as described relates to the cooling of a panel carrying electronic equipment. In this application, at least one flat enclosure 1 is fixed on at least one thermally conductive skin of the panel, and preferably between two thermally conductive skins of said panel, and the heat collected by the flat enclosure 1 is discharged to at least a heat sink, such as a radiator, by a transport tube 2. At the heat sink, a second flat chamber 1 'connected to the transport tube 2 according to the invention ensures an effective return of heat to the space. Advantages

Heat pipes meet three types of needs:

A first need is the transport of energy from a point a to a point b inside the satellite. It is understood that this requirement conditions the energy transport capacity required for the heat pipe.

A second need is the spreading or the distribution of heat on a surface acting as a radiator. This requirement conditions the minimum distance between two heat pipes on the radiator surface.

A third need is the exchange of heat. In this case, the heat pipe is typically installed directly under equipment to ensure a good heat exchange with it. The problem is then to ensure the best possible thermal coupling between the heat pipe and the equipment to which it is attached. This thermal coupling is itself a function of the wet surface of the heat pipe (surface of the heat pipe in contact with the liquid).

The device of the invention best meets these different needs through the capillary connection of wet surfaces of pregnant shapes adapted to both heat exchange and heat transport.

The device according to the invention offers heat exchange and heat transport solutions at lower cost maximizing the efficiency of heat exchange regardless of the external shape of the source or heat sink, while minimizing the risk of heat transfer. mass and congestion of the transport solution as well as the cost and complexity of the heat exchange and transport system as a whole.

It is recalled that a heat pipe ("heat pipe" in English, to distinguish from "loop heat pipe", which designates a fluid loop, with completely different behavior) uses the phase change of a fluid to ensure the collection of heat in a warm place, and its transfer as a vapor to a cold place. A tubular heat pipe is conventionally composed of a closed tube in which the liquid and gaseous phases of the same fluid coexist kept under pressure. The heat pipe makes it possible to store the heat by evaporation and to restore it by condensation of the fluid.

As a clarification, it seems necessary to distinguish a heat pipe

("Heat pipe" in English) as used in the present device, a fluid loop ("loop heat pipe" in English), with a completely different behavior, as cited in various prior art documents.

A "loop heat pipe" is in the form of a closed-loop circuit in which the fluid circulates in one direction, whereas a heat pipe is not configured in a closed loop. . Indeed, inside its cavity, the liquid and vapor phases coexist and flow in different directions between the two ends of said cavity.

In an example of such a fluid loop device, described in WO 2012/049752 (Itoh, October 2010), the liquid and gaseous phases are separated by at least one porous wall.

This difference is major because it leads to a behavior totally different from the system with an increased pumping pressure by the separative porous wall in the case of fluid loops, and operating limits induced by the physical separation of phases that do not exist in the heat pipe system due to the coexistence of the liquid and vapor phases.

Similarly, this prior art WO 2012/049752 of the field of fluid loops does not describe a "capillary" structure, according to the meaning generally known to those skilled in the art. The device of this prior document comprises a first pipe 150 carrying only liquid without capillary effect, and a second pipe 155 carrying only a vapor phase.

A document US 2006/0283577 (December 2006) also mentions a fluid loop ("A loop-type heat exchanger device (10) is disclosed, which includes and evaporator (20), to condense (40), to vapor conduit (30). and a liquid leads (50) ... "). This document does not relate to a device comprising a cavity in which the liquid and vapor phases of the same fluid coexist. On the contrary, it is clear from the view of FIG. 6 (also described in the text in paragraphs [0028] to [0029]) that the tube 30 is adapted to transport only a vapor phase fluid, not a liquid and a vapor phase.

Another earlier document relating to fluid loops, US 2009/01 14374 (Kyushu University, May 2009), describes once again a device in which the liquid and vapor phases of the same fluid do not coexist in the same cavity. transport. This is particularly apparent from the abstract "the liquid state refrigerant is supplied from the liquid supply channel 32, ... and the evaporated refrigerant is discharged from the heat removal use channel 31." Furthermore, the device described in this document does not use a capillary effect for the transport of fluid.

Claims

1. Heat exchange and transfer device consisting of a closed cavity containing a two-phase fluid,

characterized in that said device comprises:

- at least one heat exchange zone comprising a flat enclosure (1) configured in the form of a volume of which one dimension is significantly smaller than the other two, typically at least ten times smaller, said flat enclosure (1 ) having a first capillary structure (8) on all or part of its internal surface, allowing the fluid in its liquid form to wet said first capillary structure (8),

- at least one heat transport zone configured in the form of at least one tube (2) having a second capillary structure (7) on all or part of its internal face,

- said flat enclosure (1) and said at least one tube (2) being connected so that the steam can circulate freely throughout the cavity, and that continuity of capillarity is ensured between the first and the second capillary structures (7, 8) so that the liquid can wet the entire capillary structure thus formed.

2. Device according to claim 1, characterized in that, in the case of several tubes (2) connected to the same flat enclosure (1), said tubes (2) have steam conduits whose sum of passage sections is substantially equal to the steam passage section of said flat enclosure

(1) - 3. Device according to any one of claims 1 to 2, characterized in that the heat transport zone comprises a zone of increased deformability in at least one predetermined direction.

4. Device according to any one of claims 1 to 3, characterized in that it comprises two flat enclosures (1, 1 ') substantially flat located in different planes, connected by a tube (2) having two zones of twist (14, 15), said twist zones (14, 15) being arranged in at least two different planes.

5. Device according to any one of claims 1 to 4, characterized in that the flat enclosure (1) has a shape comprising at least two substantially flat zones (1 1, 12) extending in two distinct planes and connected by an edge.

6. Device according to any one of claims 1 to 5, characterized in that the thickness of the flat enclosure (1) is substantially equal to the diameter of the tube (2)

7. Device according to any one of claims 1 to 6, characterized in that a part of the external surface of the flat enclosure (1) has a locally cylindrical shape.

8. Application of a device according to any one of claims 1 to 5 to the cooling of a panel carrying electronic equipment, characterized in that at least one first flat enclosure (1) of said device is fixed on at least a thermally conductive skin of the wall, and the heat collected by said at least one first flat enclosure (1) is evacuated, by at least one transport tube (2), towards at least one second flat enclosure (1 ') arranged in contact thermal with a heat sink, such as a radiator.

9. Instrument, characterized in that it comprises a cooling device according to one of claims 1 to 7.

10. Satellite, characterized in that it comprises a device according to one of claims 1 to 7.