EP1068481B1 - Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif - Google Patents
Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif Download PDFInfo
- Publication number
- EP1068481B1 EP1068481B1 EP99910447A EP99910447A EP1068481B1 EP 1068481 B1 EP1068481 B1 EP 1068481B1 EP 99910447 A EP99910447 A EP 99910447A EP 99910447 A EP99910447 A EP 99910447A EP 1068481 B1 EP1068481 B1 EP 1068481B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- capillary
- sheets
- fluid
- sheet
- zone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
- F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
- F28D15/04—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
- F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
- F28D15/0233—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes the conduits having a particular shape, e.g. non-circular cross-section, annular
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
- F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
- F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
- F28D15/0241—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes the tubes being flexible
Definitions
- the present invention relates to the field of - devices of active fluid heat exchanges, and more specifically, of those which contain a biphasic fluid and which have capillary channels.
- biphasic is meant the fact that the fluid contained in such devices are present, in order for them to be operational, under the form of the two liquid and gas phases.
- channels which have a very small section in relation to their length, and above all which are suitable to produce pumping phenomena by capillarity on liquids.
- thermal devices with biphasic fluid comprising capillary channels capable of producing phenomena of capillary action on the liquid phase, and gas transport channels in which is confined the gas phase of the fluid, the channels capillaries communicating with the gas transport channels.
- the device In a closed loop, the device is used as a heat pipe and works independently.
- the device In this application, the device is exposed to a cold condensation zone, also called a cold source, and a hot vaporization zone, also called a hot spring.
- the fluid condenses in its liquid phase, in the cold zone and is vaporized in its gas phase in the hot zone.
- Capillary forces then act on the liquid phase of the fluid to move it from the area of condensation towards the vaporization zone.
- the gas pressure being more large in the vaporization zone than in the condensation zone, obtains a gas flow in the opposite direction to the phase displacement liquid.
- the capillary and pressure forces act alone as fluid circulation motor
- the device In open loop, the device is used as an evaporator and a pump as well as a condenser are integrated in the circuit. So that this device is functional, the fluid must arrive in its liquid form in the device and leave it in its gaseous form, to be condensed in a different element of the circuit. In the presence of gravity forces, it suffices to properly orient the device to conserve the liquid, which is denser than gas, in the liquid arrival area in the device, without it being able to return to the gas circuit downstream of the device. But in the absence of gravity forces, the liquid can get in the form of droplets dispersed in the gas phase. Canals capillaries then fix these droplets and prevent them from go back into the gas circuit downstream of the device.
- a device of this other type consists of tubes made of aluminum, internally striated to form open capillary channels on a hollow central core, serving as a gas transport channel. The still, the cylindrical geometry of these tubes does not favor a compactness and performance, optimal.
- Document US 4,019,098 relates to a transfer structure thermal aluminum made of several layers.
- This structure includes a number of heat transfer tubes, each of these tubes being composed of a central vapor channel and a certain number of parallel capillary channels. These channels are made using spreader bars.
- this device has the disadvantage low compactness and non-optimal performance. In addition, his manufacturing is relatively complex.
- An object of the invention is to provide a fluid thermal device biphasic active, flat, flexible, having a compactness and high performance, which includes in its thickness at least one channel section large enough for gas to pass easily without liquid cannot obstruct it, and at least one channel small enough to that a liquid can propagate there by capillarity. Another object of the invention is also to provide a device with low risks of stopping operation by local drying of the capillary channels.
- a device according to the invention has a structure in sheets which allows it to be flat. On the one hand, this shape makes it possible to have large contact surfaces between the device and structures that are equipped with the device. Thus the heat exchanges between the device and these structures are facilitated.
- the capillary channel is made “flat", by forming a groove in a sheet, before being integrated into the mass of the device. Therefore, the dimension perpendicular to the surface principal of the sheet, on which the groove which constitutes it is flush, can be optimized. This dimension, which will be called “thickness of the channel "may be as weak as necessary. Now the capillary pressure tends towards a maximum when the thickness of the capillary channel tends towards zero and only the “flat” design makes it possible to obtain a few microns or tens of microns necessary for a large lifting height of the liquid.
- the thickness of the capillary channel is less than 100 ⁇ m for high capillary pressure. But more preferably, this thickness of the capillary canal is approximately between 30 and 70 .mu.m.
- the dimension parallel to the main surface of the sheet determines what will be called the "capillary channel width".
- the width of the capillary channel induces the pressure drop and therefore makes it possible to obtain the necessary liquid flow.
- the "flat" arrangement increases this width as much as necessary and therefore allows a significant flow and significant thermal power.
- a capillary channel has a width of the order of 0.3 1 mm for sufficient flow and limited pressure drop.
- wetting heat pipes have a large section but the capillary pressure is very low, which does not allow a inclined use of the heat pipe.
- the section in which the thickness of the capillary is optimal has a very small width.
- each gas transport channel is determined in thickness, by the number of sheets stacked and the thickness of each sheet, and in width by the width of the corresponding zone, engraved on the entire thickness of each sheet.
- This section is large enough to reduce the gas velocity and allow a flow with low pressure drop. This avoids the limitation performance of the micro-heat pipe by the achievement of the speed of sound by the gas in the gas transport channels.
- the grooves are directly made on the sheets.
- a rigid structure is therefore not required, unlike rod stacking devices cylindrical, of the prior art.
- the thickness and nature of the material sheets can therefore be chosen to give flexibility to the device. Being able to choose thin sheets also allows you to gain compactness and optimize the transport capacity ratio of the heat on the dimensions of the device, to obtain performance high.
- the device according to the invention has a thickness much weaker than traditional heat pipes, typically 3 to 5 times lower, which induces a significant reduction potential. Due to its very small thickness, the device according to the invention can also be easily deformed, which allows bends with a very small radius curvature, close to folding. This possibility allows generating non-planar, especially cylindrical, contact surfaces to generate changes of planes by change of altitude or angular direction, or even generate “bellows” geometries making it possible to make flexible connections with heat sinks.
- the transfer of gas between the capillary channels and the gas transport channels must be optimized, among other things, to avoid drying.
- this exchange is permanent insofar as the two types channels are integrated into each other.
- the search for capillary pumping performance resulted in isolation of the capillary channel, which requires that the gas circulates in the capillary in promoting drying.
- the device according to the invention makes it possible to optimize both the transfer between capillary channels and gas transport channels and performance in capillary pumping.
- a device can comprise several channels capillaries communicating longitudinally with a transport channel gaseous. In this way, if a focal heating dries out one of the capillary channels, another of these can continue to provide circulation of the liquid phase.
- communication between channels capillaries and gas channels, along their entire length, prevents limit the exchange areas between these two types of channels and have a correct operation in closed loop, whatever the dimensions respective vaporization and condensation zones.
- the device according to the invention comprises a number sheets stacked on top of each other, equal to or more than two, each having at least one engraved area over the entire thickness to form a channel gas transport, this communicating over its entire length with a counterpart area of another sheet.
- the device according to the invention comprises at minus a closed-loop channel circuit ensuring, without motor, the circulation of the fluid contained in the circuit, between an area evaporation and a condensation zone, the capillary forces exerted on the liquid phase of the fluid contained in the capillary channels playing a pump role on the fluid.
- the device according to the invention constitutes a heat pipe.
- Such a heat pipe can be composed of several sub-assemblies sheets, each subset comprising a circuit of channels, isolated from the circuit of each other subset, each circuit being charged with a fluid whose thermodynamic properties allow working the fluid on different temperature ranges.
- the device according to the invention comprises at least one channel circuit, open on a circuit comprising a pump and a condenser, the device according to the invention then playing the role of an evaporator and the capillary forces exerted on the liquid phase fluid to fix it in the capillary channels, and distribute by capillary pumping, in these channels.
- heat transfer must be optimized to avoid temperature gradients in transfer zones, hot and cold.
- this quality of heat transfer is optimized thanks to a particular geometry of the ends.
- a “staircase” arrangement of the liquid-gas limits allows to spread the menisci of these surfaces, and thereby promote heat exchanges.
- the invention is a method for producing of devices according to the invention.
- the main construction operations of the device according to the invention are the cutting and engraving of the sheets, the welding "flat, press", and clipping. This allows the realization a large number of parts simultaneously, which is favorable for mass production. This is not possible for traditional heat pipes which must be machined one by one.
- the work, by cutting and engraving flat, of the sheets allows a wide freedom of design at reduced cost, for the device according to the invention, and facilitates the networking of conduits consisting of a transport channel gas and associated capillary channels. This feature is all the more remarkable since the engraving and cutting is done simultaneously everywhere on a whole sheet. The corresponding cost is therefore not proportional to the length of the necessary conduits.
- This method comprises a step of etching a grooves in blank sheets 1, a step of localized deposition b of an assembly material, a step of stacking c sheets previously prepared according to steps a and b, and a step mounting assembly d for welding together the sheets stacked according to step c and for example forming a heat pipe 50.
- a blank sheet 1 consists of a plate with a thickness preferably between 0.1 and 1 mm.
- the material of these sheets is for example a metal. It can be copper, nickel, iron, aluminum or one of their alloys, such as aluminum-beryllium or stainless steel. The nature of the metal of the sheets depends on the active fluid used.
- the etching step a is preferably a chemical etching with savings mask.
- the mask defines the areas of the grooves to be engraved. These grooves are differently engraved on the base sheets 2, the intermediate sheets 3 and upper sheets 4.
- This step of cutting a can be carried out in several successive operations allowing to selectively engrave, on the one hand engraved zones on all the thickness 5 of a sheet, and on the other hand of the zones engraved on a more thin.
- the zones engraved over the entire thickness 5 of the sheets are intended to supply gas transport channels 6.
- the engraved areas on a smaller thickness form a step between a first level 7, located on the upper surface of each sheet, and a second level 8. This step is intended for the formation of capillary channels 9.
- the baths of etching used for engraving, adapted to the nature of the material sheets, are conventional and known to those skilled in the art.
- the areas engraved between the first 7 and second 8 levels are made parallel to the areas engraved on the entire thickness 5 and over the entire length of the latter.
- These areas engraved up to the second level 8 are located on at least one edge of the engraved zones over the entire thickness 5, so as to pass, transversely to the longitudinal direction of the channels 6, 9, of the first level 7, second level 8, then in the areas engraved on the entire thickness 5, without going back to the first level 7.
- holes 10 and notches 11 are also engraved in the sheets, to pass respectively pawns 12 and caps 13 or plugs 14 (these elements are not shown in Figure 1). Holes 10 and notches 11 are shown on the Figures 2 to 5.
- the deposition step b of an assembly material is carried out according to strips suitable for obtaining a tight assembly of the sheets 2, 3, 4 between them and a longitudinal separation of the gas channels 6, while maintaining communication of the gas channels 6 between them, at the ends thereof.
- this assembly material is also preferably a metal.
- this metal is deposited by electroplating, with a geometry determined by a savings mask.
- the deposited metal is suitable to the mounting considered.
- This metal deposit 15 may be different depending on whether the higher of mounting step is performed, for example, by thermal compression or soldering. This metal is also chosen according to the nature of the material of the sheets 2, 3, 4.
- the deposition metal must have a melting temperature lower than that of the metal constituting the sheets. 2, 3, 4.
- the metal deposited also depends on the active fluid used. For example, when "Freon" is used as the active fluid, the deposited metal can be copper or silver.
- the thickness of the deposited metal is typically between 5 and 10 ⁇ m.
- the metal deposition 15 is carried out, on the upper face of the sheets, on the edge of the assembly formed by an area etched over the entire thickness 5 and at least one capillary channel 9, on either side of this assembly ( Figures 2 and 4).
- the metal deposition 15 is also carried out on the periphery of the sheets (FIGS. 2 and 4).
- the metal is deposited in small quantities so that it does not come to fill, during assembly, the zones intended to form the capillary channels 9.
- the thickness of the metal deposit 15 is 5 to 10 ⁇ m.
- the stacking step c of the sheets, previously prepared according to steps a and b is for example carried out by successively vertically placing three intermediate sheets 3 on a base sheet 2 and an upper sheet 4 on the intermediate sheet 3 from above.
- the sheets 2, 3, 4 are stacked, according to step c, presenting the engraved areas up to the second level 8, facing upwards.
- the zones engraved over the entire thickness 5 are placed opposite one another and define the gas transport channels 6.
- the stack of sheets 2, 3, 4 defines a heat pipe 50. As shown in FIG.
- this heat pipe 50 can also be placed on a support 16 ( tools) and cover the whole with a sheet 17 making it possible to isolate the heat pipe 50 from the weights necessary for assembly.
- the pins 12 are optionally arranged in the holes 10, so as to keep the sheets strictly aligned during the subsequent mounting step d
- the mounting step d is preferably carried out by brazing.
- the brazing metal forms a liquid phase which wets the areas on which it is deposited and the areas of the adjacent sheet, located opposite them. It thus ensures the connection of the sheets pressed one on the other to ensure contact.
- This brazing can be carried out under vacuum (10 -5 mbar) or under a gaseous atmosphere, but preferably under a non-oxidizing atmosphere.
- An under layer is possibly deposited between the sheet and the brazing metal. The sheets are thus joined together, in a leaktight manner, all around each sheet and between each set constituted by a gas transport channel and at least one capillary channel.
- Caps 13 and plugs 14 are arranged in the orifices made by superimposing the notches 11.
- the two-phase fluid is introduced into the evaporator, using the queusots 13 before these are closed.
- the fluid used depends on the intended operating temperature range. It can be H 2 O, NH 3 , acetone, "Freon”, methane, ethane, etc.
- the mounting step d is carried out by brazing. It can also be carried out by thermo-compression. In this case, it is preferably carried out under vacuum to avoid passivation of the surface, by fixing non-metallic compounds (O 2 , N 2 , H 2 O, volatile fats, etc.).
- the thermo-compression temperature is located approximately 50 ° C below the melting temperature of the metal deposited in step b.
- the pressure exerted on the areas to be welded is approximately 0.1 N / mm 2 .
- a heat pipe 50 This includes a base sheet 2, three intermediate sheets 3 and one top sheet 4.
- the basic sheet 2 has a shape elongate. It has an overall dimensions of 215 mm long, 69 mm wide and 0.25 mm thick. It includes engraved areas of the first level 7 to second level 8. The distance between the first 7 and second 8 levels is 70 ⁇ m. The width of these areas is approximately 1 mm.
- a metal deposit 15 is made, on the first level 7, on the periphery of the sheet and along equidistant lines, parallel and generally longitudinal. Four holes 10 are engraved in the entire thickness of the base sheet 2, outside the line formed by the metal deposit 15, at the periphery.
- the intermediate sheets 3 have the same shape as the basic sheet 2. They also have a overall dimensions of 215 mm long, 69 mm wide, but a thickness of 200 ⁇ m.
- an intermediate sheet includes engraved zones over its entire thickness 5. These zones are located at the level of its longitudinal ends to form holes 10, at the level ends of its longitudinal edges to form notches 11 and at the level of equidistant parallel lines and globally longitudinal. These are seven in number and are intended for form gas transport channels 6. The three most central lines are longer than the others and are extended deeper in the area between the two notches 11 arranged on the two opposite longitudinal edges of the intermediate sheet 3. All these lines lead to an area at each of their ends transverse and engraved from the first level 7 to the second level 8. Thus, these engraved zones from the first level 7 to the second level 8 define capillary zones, which when bathed by the liquid phase of the condensed fluid at this level, redistribute the liquid in all capillary channels 9.
- an intermediate sheet 3 includes also engraved areas from the first level 7 to the second level 8.
- the distance between the first 7 and second 8 levels is 70 ⁇ m.
- zones are etched up to the second level 8, while leaving on the periphery and between each channel 6, areas not engraved on the first level 7.
- the engraved areas up to the second level 8 communicate with each other and with the notches 11.
- the metal deposition 15 is carried out at the periphery of the sheet and according to generally longitudinal lines, on the first level 7, according to the same geometry as the metal deposit 15 of the base sheet 2.
- an upper sheet 4 has a shape elongated, identical to that of base sheet 2 and sheets intermediate 3. Its overall length and width are identical to those basic 2 and intermediate 3 sheets. Its thickness is 200 ⁇ m. he comprises two holes 10 at each of its longitudinal ends.
- a basic sheet 2, three intermediate sheets 3 and a sheet upper 4 are assembled, for example according to the method described above, to form a heat pipe 50 having a thickness of the order of millimeter (Fig. 6a).
- This heat pipe 50 includes seven transport channels gas 6. Eight capillary channels 9 lead to each channel of gas transport 6 (Fig. 6b), or 56 capillary channels 9 in all. Each capillary channel 9 has a section of approximately 70 ⁇ m by 1 mm.
- the ribs of the structure stacked schematically shown in Figure 6, are not At scale.
- Figure 6a in particular has a very dilated scale in the direction perpendicular to the plane of the sheets, to show the capillary channels 9.
- this heat pipe 50 is provided with pipes 13, as well as plugs 14 and is transferred to a support 16 and covered of a sheet 17.
- the support 16 consists of a 220 mm plate of long, 76 mm wide and 10 mm thick.
- Sheet 17 has a length and an overall width of 219 and 73 mm respectively. Its thickness is 1 mm.
- the heat pipe 50 is held on the support 16 with the sheet 17 thanks to pawns 12. It is loaded with weights isolated from sheet 17 by shims in alumina which avoid welding of the weights on the sheet 17.
- Other variants of the device according to the invention can be considered.
- Such a device can, for example, include more sheets intermediaries 3.
- the channels capillaries 9 intended for the transport of the liquid phase of the fluid by capillarity and the gas transport channels 6 can be made of different ways.
- a heat pipe 50 has been described above. with a capillary channel 9 located on either side of each etched area over the entire thickness 5 of the sheets. But a channel may not be provided capillary 9 only on one side of each zone engraved over the entire thickness 5. It is also possible to superimpose several heat pipes 50, one on top of the other.
- the devices described above include metal sheets, but we will not stray from the spirit of the invention if the sheets are in plastic, composite, etc.
- the assembly material is then chosen accordingly. It can be a polymer adhesive, for example. he may even be envisaged to make welds between the sheets, by fusion, without assembly material.
- the capillary channels 9 are formed by chemical etching of grooves in a sheet. But it can also be envisaged to produce these grooves by deposition of extra material on the sheets.
- Devices according to the invention can find many applications in space thermal, avionics, electronics, IT, etc.
- a device according to the invention both by its shape and by the type of process which makes it possible, allows their integration easy to electronic circuits 20.
- heat pipes 50 arranged on electronic circuits 20 allow cooling of hot zones 21 on which are installed components 22, heat generators, in conveying the heat to return zones 23, even if necessary bypass holes or other components 22.
- a printed circuit 20 made of epoxy resin can be glued, flat on each main face of a heat pipe 50, by sandwiching the latter.
- the gas 6 and capillary 9 transport channels of the heat pipe 50 directly transfer the heat, from the areas of the printed circuit 20 where components 22 are to be cooled, to a heat exchanger rack 40 or a radiator.
- a thermal clamp 41 conducts the heat between the heat pipe 50 and the rack 40 or the radiator.
- the heat pipe 50 therefore plays here the role of support for the printed circuit 20 in addition to its function as thermal conductor.
- the thickness of which is less than 3 mm, it is possible to evacuate on the order of 10 W / cm 2 over at least 5 cm 2 .
- a heat pipe 50 can be shaped as a bellows, to cool, for example, a mobile detector 30. Just place this bellows so as to have folds of this bellows perpendicular to the plane in which the movement generated by a vertical displacement device 31 and the movement generated by a horizontal displacement device 32, the heat pipe 50 connecting the detector 30 to a heat return element 33.
- the importance of the first and third components are a consequence of the low thermal conductivity of the fluid and the concentration of the flux near the limit between capillary channels 9 and gas transport channels 6.
- the second component is the only fundamentally linked to the physical process generating the operation of the device according to the invention, in its heat pipe function.
- a capillary channel 9 has an overall U shape with two parallel side walls 25 corresponding to the branches of the U and a bottom wall 26.
- the bottom wall 26 is perpendicular to the side walls 25 between which it extends.
- each side wall 25 has a longitudinal edge linked to the bottom wall. 26 and a free longitudinal edge 27 or 28 parallel to the previous edge.
- the increase in the areas of evaporation S and of condensation makes it possible to reduce the first and third components mentioned of the temperature differential between the hot source and the cold source, thanks to a reduction in the concentration of the flux in the vicinity of the limit between the capillary channel 9 and the gas transport channel 6.
- the different capillary channels 9 can all have identical dimensions. However, according to an advantageous variant, they can also have different dimensions, for example, with the particular aim of optimizing the conduction of heat towards the vaporization zones where the evaporation surfaces S are located .
- the offset entered the free longitudinal edges 27, 28 can be variable or constant over the entire length of the capillary channel 9.
- the heat collection and transfer systems that act as sinks thermals generally only allow heat to be removed form of a very weak heat flux, at the level of the exchange surface between the device and these collection and heat transfer systems. So to increase the heat power exchanged, it is necessary to increase this exchange surface.
- FIG. 13 represents an example where two of these conduits 51 are split.
- each conduit 51 is divided, at the level of the cold source, in two ramifications 52.
- Each of these two ramifications 52 leads to a collector 53 connecting together, at the source cold, all the ramifications 52 of all the conduits 51.
- All of the ramifications 52 opening into a duct 51 must have a cross section total of capillary channels 9 sufficient for all of the fluid condensate can return by capillarity, from the cold source to the source hot, in the various capillary channels 9 of the conduits 51 located between these two sources.
- the total section of these different channels capillaries 9 of the different branches 52 opening into a conduit 51 is equal to that of all the capillary channels 9 of this conduit 51.
- the set of ramifications 52 constitutes a condenser
- the capillary channels 9 of each branch are advantageously superimposed on each other so that the longitudinal free edges 26, 27 are offset relative to each other, as described above, in order to increase the condensing surface.
- a arrangement and stacking of sheets 2, 3, 4 so as to form a triangular gas transport channel 6, at the branches 52 constitutes an advantageous configuration which makes it possible to minimize the journeys heat conduction mentioned above. As indicated by arrows, in this figure, the heat flux is very distributed.
- the volume of the capillary part is of the same order of magnitude than that corresponding to the gas transport channels 6. And the filling is done with a “vacuum” fluid, ie under the sole saturated vapor pressure. This promotes the appearance of vapor bubbles almost everywhere in the filling circuit.
- the manipulation of the phase liquid of the heat transfer fluid, in small quantities, is therefore very delicate. Through therefore, the filling accuracy is no better than more or minus ten percent, relative to the target amount of liquid fluid. What remains insufficient to avoid the problems mentioned above.
- the Applicant proposes to develop at least one reservoir 54 having a volume comparable to that of a gas transport channel 6 and on which open capillary channels 9, which put it in communication with the rest of the device according to the invention.
- the volume of the entire tank (s) 54 must be preferably approximately equal to twenty percent of the quantity liquid fluid, intended for filling the device according to the invention, i.e. also approximately twenty percent of the capillary volume of the device according to the invention.
- the reservoir 54 constitutes a reserve but also accommodates excess fluid.
- Each tank 54 must be located in the cold part of the device according to the invention. But it should not be located at the coldest point, because if this was the case, it helped to reduce the capillary pressure bringing back the fluid liquefied from the part of the device according to the invention forming the condenser towards that forming an evaporator.
- a satisfactory arrangement consists in placing each reservoir 54 with the ramifications 52 of the condenser.
- each reservoir 54 is kept cold by the contact of the device according to the invention with the external cold source. Not being heated by the circulation of gas, it is colder than the ramifications 52 of the condenser. However, being in their neighborhood, it is warmed by them and cannot be much colder.
- Figure 15 illustrates such an arrangement.
- a set of two tanks 54 is located between two sets of two ramifications 52.
- Each reservoir 54 is surrounded by a zone of channels capillaries 9, leading to the manifold 53 communicating with the four ramifications 52.
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
Description
- au moins un canal capillaire ayant une section adaptée pour que la phase liquide du fluide puisse y être pompée par des forces capillaires,
- au moins un canal de transport gazeux, ayant une section supérieure à celle d'un canal capillaire
- et au moins deux feuillets,
- la figure 1 représente schématiquement l'ensemble des étapes d'un exemple non limitatif de procédé mis en oeuvré pour réaliser un dispositif selon l'invention ;
- la figure 2 est une vue en élévation de dessus d'un feuillet de base d'un mode de réalisation d'un dispositif conforme à la présente l'invention ;
- la figure 3 est une vue en élévation de dessous d'un feuillet intermédiaire du dispositif selon l'invention correspondant au même mode de réalisation que celui de la figure 2 ;
- la figure 4 est une vue en élévation de dessus d'un feuillet intermédiaire du dispositif selon l'invention correspondant au même mode de réalisation que celui de la figure 2 ;
- la figure 5 est une vue en élévation de dessus d'un feuillet supérieur du dispositif selon l'invention correspondant au même mode de réalisation que celui de la figure 2 ;
- la figure 6 représente schématiquement en coupe, selon la ligne A-A, un empilement des feuillets représentés aux figures 2, 3, 4 et 5 ; la figure 6a représenté un tel empilement avec une échelle très dilatée dans la direction perpendiculaire au plan des feuillets ; la figure 6b représente de manière plus détaillée la section d'un canal de transport gazeux et des canaux capillaires associés adjacents ;
- la figure 7 représente schématiquement une vue en perspective d'un exemple de dispositif selon l'invention, reposant sur un outillage de montage ;
- la figure 8 représente schématiquement, vue de dessus, une application d'un dispositif selon l'invention, au refroidissement de composants sur circuits électroniques ;
- la figure 9 représente schématiquement, en coupe longitudinale, un dispositif selon l'invention, pris en sandwich entre deux circuits imprimés ;
- la figure 10 représente schématiquement un exemple d'utilisation d'un dispositif selon l'invention, pour le refroidissement d'un détecteur ;
- la figure 11 est une coupe schématique transverse d'un canal capillaire dans une variante du dispositif représenté sur la figure 6 ;
- la figure 12 est une coupe schématique transverse d'un canal de transport gazeux entouré de ses canaux capillaires associés, dans une variante du dispositif représenté sur la figure 6;
- la figure 13 est une vue de dessus, en transparence, selon un plan parallèle au plan principal d'une variante du dispositif correspondant au mode de réalisation représenté sur les figurés 2 à 6, d'une partie formant condenseur dans cette variante ;
- la figure 14 est une coupe schématique transverse, selon la ligne B-B de la figure 13, d'une ramification, située dans la partie formant condenseur représentée sur la figure 13 ; et
- la figure 15 est une vue de dessus, en transparence, selon un plan parallèle au plan principal d'une variante du dispositif correspondant au mode de réalisation représenté sur les figures 2 à 6, d'une partie formant réservoir dans cette variante. Préférentiellement, mais de manière non limitative, un dispositif selon l'invention peut être réalisé selon le procédé illustré par la figure 1.
- un gradient de température entre la surface du dispositif au niveau de la source chaude et la surface d'évaporation (=46% du total) ;
- un différentiel de température entre la surface d'évaporation et la surface de condensation du liquide (=8%) ;
- un gradient de température entre la surface de condensation et la surface du dispositif au niveau de la source froide (= 46% du total).
- si le remplissage était trop faible, une partie des canaux capillaires 9 serait asséchée et, compte tenu du principe de fonctionnement du dispositif selon l'invention, cet assèchement se produirait dans la partie du dispositif selon l'invention formant évaporateur, ce qui le rendrait le dispositif inopérant; mais
- si le remplissage était trop important, une partie des canaux de transport gazeux 6 serait envahie par le fluide en excès et, compte tenu du même principe, l'excès serait localisé dans la partie du dispositif selon l'invention formant le condenseur, ce qui le rendait également inopérant.
Claims (18)
- Dispositif thermique à fluide biphasique actif, comprenantau moins un canal capillaire (9) ayant une section adaptée pour que la phase liquide du fluide puisse y être pompée par des forces capillaires,au moins un canal de transport gazeux (6) ayant une section supérieure à celle d'un canal capillaire (9), etau moins deux feuillets (2, 3, 4),
caractérisé en ce que l'un (3) des feuillets (2, 3, 4) comporte au moins une zone gravée sur toute son épaisseur pour contribuer à la formation d'un canal de transport gazeux (6), cette zone gravée étant bordée longitudinalement d'une rainure contribuant à la formation d'un canal capillaire (9), lorsque ce feuillet (3) est recouvert d'un autre feuillet (3, 4), ledit canal capillaire (9) communiquant longitudinalement avec ledit canal de transport gazeux (6). - Dispositif selon la revendication 1, caractérisé en ce que chaque canal capillaire (9) a une dimension inférieure à approximativement 100 µm, perpendiculairement à la surface principale du feuillet (2, 3), sur laquelle affleure la rainure qui le constitue.
- Dispositif selon l'une des revendications précédentes, caractérisé en ce que chaque canal capillaire (9) a une dimension comprise approximativement entre 50 et 70 µm, perpendiculairement à la surface principale du feuillet (2, 3), sur laquelle affleure la rainure qui le constitue.
- Dispositif selon l'une des revendications précédentes, caractérisé en ce qu'il comprend un nombre de feuillets (2, 3, 4) empilés les uns sur les autres, égal ou supérieur à deux, chacun ayant au moins une zone gravée sur toute épaisseur pour former un canal de transport gazeux (6), celle-ci communiquant sur toute sa longueur avec une zone homologue d'un autre feuillet (3).
- Dispositif selon l'une des revendications précédentes, caractérisé en ce que les feuillets (2, 3, 4) sont réalisés en cuivre, nickel, fer ou aluminium ou encore un de leurs alliages, tel que l'aluminium-béryllium ou l'acier inoxydable.
- Dispositif selon l'une des revendications précédentes, caractérisé en ce qu'il comprend au moins un circuit de canaux (6, 9) fonctionnant en boucle fermée et assurant, sans moteur, la circulation du fluide contenu dans le circuit, entre une zone d'évaporation et une zone de condensation, les forces capillaires exercées sur la phase liquide du fluide contenue dans les canaux capillaires (9) jouant un rôle de-pompe sur le fluide.
- Dispositif selon la revendication 6, caractérisé en ce qu'il est. composé de plusieurs sous-ensembles de feuillets (2, 3, 4), chaque sous-ensemble comprenant un circuit de canaux (6, 9) isolé du circuit de chaque autre sous-ensemble, chaque circuit étant chargé d'un fluide dont les propriétés thermodynamiques permettent un travail du fluide sur des domaines de température différents.
- Dispositif selon l'une des revendications 1 à 5, caractérisé en ce qu'il comprend au moins un circuit de canaux (6, 9) ouvert sur un circuit comprenant une pompe et un condenseur, le dispositif jouant le rôle d'un évaporateur et les forces capillaires exercées sur la phase liquide du fluide permettant de fixer celle-ci dans les canaux capillaires (9) et de le répartir par pompage capillaire.
- Dispositif selon l'une des revendications précédentes, caractérisé par le fait qu'il comporte un canal capillaire (9) présentant une forme globale en U avec deux parois de côté (25) parallèles correspondant aux branches du U et une paroi de fond (26), chaque paroi de côté (25) ayant un bord longitudinal lié à la paroi de fond (26) et un bord longitudinal libre (27 ou 28), parallèle au bord précédent, les bords longitudinaux libres (27, 28) étant décalés l'un par rapport à l'autre.
- Dispositif selon l'une des revendications précédentes, caractérisé par le fait que les feuillets (2, 3, 4) sont disposés et empilés de manière à former un canal de transport gazeux (6) dont la section transverse est globalement triangulaire, avec de bords libres longitudinaux (27, 28) en escalier, pour minimiser des trajets de conduction thermique.
- Dispositif selon l'une des revendications précédentes, caractérisé par le fait qu'il comporte un conduit (51), constitué d'un canal de transport gazeux (6) et d'au moins un canal capillaire (9), se divisant en deux ramifications (52).
- Dispositif selon l'une des revendications précédentes, caractérisé par le fait qu'il comporte un réservoir (54) situé dans une. partie froide du dispositif, pour constituer une réserve de fluide ou recueillir le fluide en excès.
- Procédé de fabrication de dispositifs thermiques à fluide biphasique dans lequel on assemble au moins deux feuillets (2, 3, 4), caractérisé par le faitque l'on grave l'un des feuillets (2, 3, 4) dans une zone, sur toute son épaisseur, cette zone étant destinée à contribuer à la formation d'un canal de transport gazeux (6),que l'on forme une rainure bordant longitudinalement ladite zone gravée sur toute son épaisseur, etque l'on recouvre la face de ce feuillet (3) sur laquelle se trouve ladite rainure d'un autre feuillet (3, 4) pour former un canal capillaire (9).
- Procédé selon la revendication 13, caractérisé en ce que chaque zone gravée sur toute l'épaisseur d'un feuillet (3) et les rainures sont gravées chimiquement
- Procédé selon l'une des revendications 13 et 14, caractérisé en ce qu'il comprend une étape d'assemblage par brasage sous atmosphère non oxydante.
- Procédé selon l'une des revendications 13 à 15, caractérisé en ce qu'il comprend une étape de dépôt d'un matériau d'assemblage selon des bandes adaptées pour obtenir un assemblage étanche des feuillets (2, 3, 4) entre eux et une séparation longitudinale des canaux gazeux (6), tout en maintenant une communication des canaux gazeux (6) entre eux, aux extrémités de ceux-ci.
- Procédé selon la revendication 16, caractérisé en ce que le matériau d'assemblage est un métal dont le point de fusion est inférieur à celui du métal des feuillets (2, 3, 4).
- Procédé selon l'une des revendications 16 et 17, caractérisé en ce que le matériau d'assemblage est déposé par galvanoplastie, avec une géométrie déterminée par un masque d'épargne.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9803902A FR2776763B1 (fr) | 1998-03-30 | 1998-03-30 | Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif |
FR9803902 | 1998-03-30 | ||
FR9814462A FR2776764B1 (fr) | 1998-03-30 | 1998-11-18 | Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif |
FR9814462 | 1998-11-18 | ||
PCT/FR1999/000722 WO1999050607A1 (fr) | 1998-03-30 | 1999-03-29 | Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1068481A1 EP1068481A1 (fr) | 2001-01-17 |
EP1068481B1 true EP1068481B1 (fr) | 2003-09-03 |
Family
ID=26234224
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP99910447A Expired - Lifetime EP1068481B1 (fr) | 1998-03-30 | 1999-03-29 | Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1068481B1 (fr) |
DE (1) | DE69910996T2 (fr) |
FR (1) | FR2776764B1 (fr) |
WO (1) | WO1999050607A1 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108568703A (zh) * | 2018-04-20 | 2018-09-25 | 西安交通大学 | 一种用于高速电主轴转轴表面冷却的柔性热管 |
US20220011054A1 (en) * | 2020-07-10 | 2022-01-13 | Nidec Chaun-Choung Technology Corporation | Heat conducting member |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2803908B1 (fr) * | 2000-01-13 | 2002-08-23 | Atmostat Etudes Et Rech S | Procede de fabrication de dispositifs de transfert thermique et dispositifs obtenus par ce procede |
WO2002012590A1 (fr) * | 2000-08-10 | 2002-02-14 | Atmostat Etudes Et Recherches | Composite beryllium-aluminium a surface microporeuse pour impregnation, peinture ou collage |
US20040011509A1 (en) * | 2002-05-15 | 2004-01-22 | Wing Ming Siu | Vapor augmented heatsink with multi-wick structure |
FR3080172B1 (fr) * | 2018-04-11 | 2020-05-08 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Caloduc a pompage capillaire a rainures reentrantes offrant un fonctionnement ameliore |
FR3138942A1 (fr) * | 2022-08-17 | 2024-02-23 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Caloduc de type à pompage capillaire, à rainures réentrantes intégrant au moins un substrat poreux à l’évaporateur. |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4019098A (en) * | 1974-11-25 | 1977-04-19 | Sundstrand Corporation | Heat pipe cooling system for electronic devices |
US4602679A (en) * | 1982-03-22 | 1986-07-29 | Grumman Aerospace Corporation | Capillary-pumped heat transfer panel and system |
DE3402003A1 (de) * | 1984-01-21 | 1985-07-25 | Brown, Boveri & Cie Ag, 6800 Mannheim | Leistungshalbleitermodul |
US5309457A (en) * | 1992-12-22 | 1994-05-03 | Minch Richard B | Micro-heatpipe cooled laser diode array |
US5458189A (en) * | 1993-09-10 | 1995-10-17 | Aavid Laboratories | Two-phase component cooler |
DE19626227C2 (de) * | 1996-06-29 | 1998-07-02 | Bosch Gmbh Robert | Anordnung zur Wärmeableitung bei Chipmodulen auf Mehrschicht-Keramikträgern, insbesondere für Multichipmodule, und Verfahren zu ihrer Herstellung |
US6167948B1 (en) * | 1996-11-18 | 2001-01-02 | Novel Concepts, Inc. | Thin, planar heat spreader |
-
1998
- 1998-11-18 FR FR9814462A patent/FR2776764B1/fr not_active Expired - Fee Related
-
1999
- 1999-03-29 DE DE69910996T patent/DE69910996T2/de not_active Expired - Fee Related
- 1999-03-29 EP EP99910447A patent/EP1068481B1/fr not_active Expired - Lifetime
- 1999-03-29 WO PCT/FR1999/000722 patent/WO1999050607A1/fr active IP Right Grant
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108568703A (zh) * | 2018-04-20 | 2018-09-25 | 西安交通大学 | 一种用于高速电主轴转轴表面冷却的柔性热管 |
US20220011054A1 (en) * | 2020-07-10 | 2022-01-13 | Nidec Chaun-Choung Technology Corporation | Heat conducting member |
Also Published As
Publication number | Publication date |
---|---|
WO1999050607A1 (fr) | 1999-10-07 |
EP1068481A1 (fr) | 2001-01-17 |
DE69910996T2 (de) | 2004-07-22 |
FR2776764B1 (fr) | 2000-06-30 |
DE69910996D1 (de) | 2003-10-09 |
FR2776764A1 (fr) | 1999-10-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2344827B1 (fr) | Dispositif de régulation thermique à réseau de caloducs capillaires interconnectés | |
EP3553445B1 (fr) | Caloduc a pompage capillaire a rainures reentrantres offrant un fonctionnement ameliore | |
US6843308B1 (en) | Heat exchanger device using a two-phase active fluid, and a method of manufacturing such a device | |
EP3207324B1 (fr) | Caloduc plat avec fonction reservoir | |
EP3612782B1 (fr) | Évaporateur à interface de vaporisation optimisée | |
EP1068481B1 (fr) | Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif | |
FR2809484A1 (fr) | Bloc echangeur de chaleur | |
FR2865027A1 (fr) | Ailette pour echangeur de chaleur et echangeur de chaleur muni de telles ailettes | |
EP3728977B1 (fr) | Echangeur de chaleur avec elements et plaques a texturation de surface | |
FR2591504A1 (fr) | Procede d'evaporation-condensation de films ruisselants, elements pour sa mise en oeuvre et ses applications. | |
EP3553444B1 (fr) | Caloduc a artere a fonctionnement ameliore | |
FR2776763A1 (fr) | Dispositif d'echanges thermiques a fluide biphasique actif et procede de fabrication d'un tel dispositif | |
FR3138943A1 (fr) | Caloduc à section transversale non cylindrique, comprenant un évaporateur à structure d’interface vapeur/liquide améliorée afin d’augmenter la limite d’ébullition. | |
EP4325156A1 (fr) | Caloduc de type à pompage capillaire, à rainures réentrantes intégrant au moins un substrat poreux à l'évaporateur | |
EP3553443A1 (fr) | Thermosiphon et caloduc pulse de realisation simplifiee | |
WO2019122663A1 (fr) | Element intercalaire a texturation de surface, echangeur de chaleur comprenant un tel element | |
FR3075335B1 (fr) | Echangeur de chaleur avec elements intercalaires superposes | |
JP7422600B2 (ja) | ループ型ヒートパイプ及びその製造方法 | |
FR3128279A1 (fr) | Caloduc de type à pompage capillaire avec rainures réentrantes à limites d’ébullition et capillaire augmentées. | |
WO2023066753A1 (fr) | Caloduc de type a pompage capillaire avec rainures reentrantes a gestion de liquide amelioree | |
FR3128278A1 (fr) | Module pour la fabrication d’un caloduc a pompe capillaire a rainures réentrantes | |
FR3075341A1 (fr) | Echangeur de chaleur avec elements intercalaires a texturation de surface |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20001016 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB |
|
17Q | First examination report despatched |
Effective date: 20010627 |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE FR GB |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REF | Corresponds to: |
Ref document number: 69910996 Country of ref document: DE Date of ref document: 20031009 Kind code of ref document: P |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 20031205 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20040604 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20070330 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20070416 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20070328 Year of fee payment: 9 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20080329 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20081125 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20081001 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20080331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20080329 |