(19)
(11)EP 3 115 728 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
01.05.2019 Bulletin 2019/18

(21)Application number: 16175004.7

(22)Date of filing:  17.06.2016
(51)Int. Cl.: 
F28D 15/02  (2006.01)
H01L 23/427  (2006.01)
F28D 15/04  (2006.01)
H05K 7/20  (2006.01)

(54)

COOLING APPARATUS AND METHOD

KÜHLVORRICHTUNG UND -VERFAHREN

APPAREIL ET PROCÉDÉ DE REFROIDISSEMENT


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 09.07.2015 EP 15176089

(43)Date of publication of application:
11.01.2017 Bulletin 2017/02

(73)Proprietor: ABB Schweiz AG
5400 Baden (CH)

(72)Inventors:
  • Agostini, Bruno
    8006 Zürich (CH)
  • Torresin, Daniele
    5413 Birmenstorf (CH)
  • Agostini, Francesco
    8005 Zürich (CH)
  • Riedel, Gernot
    5406 Baden-Rütihof (CH)
  • Habert, Mathieu
    68170 Rixheim (FR)

(74)Representative: Kolster Oy Ab 
Salmisaarenaukio 1 P.O. Box 204
FI-00180 Helsinki
FI-00180 Helsinki (FI)


(56)References cited: : 
EP-A1- 2 527 776
US-A- 6 073 683
US-A1- 2007 187 072
US-A- 4 770 238
US-A1- 2004 206 480
US-B1- 6 360 814
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION


    FIELD OF THE INVENTION



    [0001] This invention relates to a cooling apparatus and to a method for manufacturing a cooling apparatus. An apparatus according to the preamble of claim 1 is known from US 2007/0187072.

    DESCRIPTION OF PRIOR ART



    [0002] A trend in electric devices has for a long time been that the size of the devices should be made smaller simultaneously as the devices become more efficient, which leads to devices with a higher power density. One of the problems occurring due to this is to provide sufficient cooling in order to avoid problems due to excessive raise of the operating temperature. Conventional heat sinks dissipating heat into surrounding air are not able to fulfill the requirements in all implementations.

    [0003] Previously there is known a cooling apparatus comprising an evaporator and condenser. The evaporator receives a heat load into a first fluid and passes on this first fluid to a condenser dissipating the heat load into surroundings.

    [0004] The properties provided by the above mentioned known apparatus are, however, still not optimal.

    SUMMARY OF THE INVENTION



    [0005] An object of the present invention is to provide a cooling apparatus capable of providing efficient and adequate cooling. This object is achieved with a cooling apparatus according to independent claim 1, a power module according to independent claim 9 and a manufacturing method according to independent claim 10.

    [0006] The use of an evaporator comprising porous aluminum having a capillary structure with a plurality of capillary pores and a plurality of larger evaporator channels makes it possible to easily obtain a cooling apparatus having excellent cooling properties and which can be advantageously utilized in various implementations. In this connection the term "aluminum" refers not only to pure aluminum but also to various aluminum alloys, An alternative of manufacturing such a cooling apparatus is to utilize 3D printing for the manufacturing of the evaporator or a part of it. In that way an evaporator with an appropriate and efficient structure can be obtained in a cost efficient way.

    BRIEF DESCRIPTION OF DRAWINGS



    [0007] In the following the present invention will be described in closer detail by way of example and with reference to the attached drawings, in which

    Figures 1 to 4 illustrate a first embodiment of a cooling apparatus and of a method for manufacturing a cooling apparatus,

    Figures 5 to 8 illustrate dimensioning of the cooling apparatus, and

    Figure 9 illustrates an evaporator.


    DESCRIPTION OF AT LEAST ONE EMBODIMENT



    [0008] Figures 1 to 4 illustrate a first embodiment of a cooling apparatus and of a method for manufacturing a cooling apparatus. In the following explanation it is by way of example assumed that the cooling apparatus is a CLHP (Capillary Loop Heat Pipe) providing cooling by utilizing thin film evaporation. Figure 1 illustrates the a porous structure of an evaporator 1 which additionally may include other parts, Figure 2 illustrates use of the evaporator 1 in connection with a compensation chamber 2, Figure 3 is an outside view of the cooling apparatus 3 and Figure 4 illustrates details of the cooling apparatus 3 with the housing 4 removed.

    [0009] The evaporator 1 illustrated in Figure 1 may be manufactured by utilizing a 3D printer, for instance. One alternative is to 3D print the evaporator 1 of brazable aluminum. This brazable aluminum material may in practice consist of an aluminum alloy, in other words a mix of aluminum with other materials. This makes it possible to obtain a capillary porous structure with micro pores throughout the entire structure of the evaporator 3. Additionally, the evaporator provides a high heat transfer area which makes it able to handle high heat flux densities. In order to ensure that fluid in vapor state can efficiently propagate through the evaporator, the evaporator is provided with evaporator channels 6 extending through the evaporator 1 from a second end 8 of the evaporator 1 to a first end of the evaporator 7. The second end 8 of the evaporator 1 is at the location where fluid can enter the evaporator channels 6 from the lowermost part of the evaporator channel 6, as illustrated in Figure 2 and the first end of the evaporator is at the location where fluid can exit the evaporator channels 6 from the uppermost part of the evaporator 1, as illustrated in Figure 4. The evaporator channels 6 have a larger size, such as diameter than the pores 5. Tough the size of the pores is referred to as the pore diameter, this does not mean that the pores necessarily are circular. In practice the shape and size of the single pores in the same evaporator may vary.

    [0010] From Figure 1 it can be seen that the evaporator channels 6 are located in a middle part of the illustrated evaporator 1, in other words not in the first surface 9 or in the second surface 16 (as in the evaporator illustrated in Figure 9), but embedded at a location between the first surface 9 and the second surface 16. The term "embedded" refers to a solution where the evaporator channels 6 are located within the material of the evaporator 1 and do not open up into the first surface 9 or second surface 16 of the evaporator. An advantage with such a solution which can be obtained by 3D printing is that a relatively large first surface 9 remains intact (except for the pores 5) for heat transfer such that heat can efficiently be transferred to the evaporator 7. The evaporator channels 6 are arranged in several layers, in other words embed them at different depths between the first surface 9 and the second surface 16, as illustrated in Figure 1. This makes it possible to obtain a relatively large total cross sectional flow area for the evaporator channels 6.

    [0011] In order to manufacture a cooling apparatus utilizing an evaporator 1 a compensation chamber 2 as illustrated in Figure 2 is used. In Figure 2 the evaporator is arranged with a first surface 9 in thermal contact with a surface of a base plate 10. Once the base plate 10 receives a heat load from one or more electric components 11 the heat load is transferred to first fluid present in the evaporator 1. The heat load vaporizes the first fluid in the wick of the evaporator 1. Driven by the vapor pressure, the first fluid flows as vapor 12 through the straight evaporator channels 6 towards the condenser 14.

    [0012] Only the second end 15 of the condenser 14 is illustrated in Figure 2. The second end 15 of the condenser is at the location where fluid can exit the condenser and enter the compensation chamber. In the condenser 14 the first fluid condenses into liquid 13, which enters the compensation chamber 2. The capillary pressure generated by the liquid/vapor interface (meniscus) in the evaporator 1 wick surface provides a pumping force that ensures circulation of the first fluid within the cooling apparatus irrespectively of the orientation in which the cooling apparatus is utilized. Consequently, the cooling apparatus works as an orientation free capillary loop heat pipe. Therefore the cooling apparatus is easy to implement in a product.

    [0013] The liquid 13 obtained from the second end 15 of the condenser 14 enters the compensation chamber 2. In the compensation chamber 2 capillary forces pump the first fluid in liquid 13 state along a second surface 16 of the evaporator 1. This ensures a permanent wetting of the evaporator 1 areas receiving heat from the base plate 10. Pores 5 opening up into the second surface 16 of the evaporator 1 are thereby provided with first fluid. The fluid entering the pores 5 is moved by capillary forces deeper into the structure of the evaporator 1 in a direction which is generally perpendicular to the direction of the evaporator channels 6, as illustrated by arrows 17. Consequently, the compensation chamber 2 acts as a liquid reservoir ensuring a sufficient supply of first fluid in liquid state to the evaporator 1.

    [0014] The evaporator 1 illustrated in Figure 1 and utilized in a cooling apparatus as illustrated in Figure 2 may be manufactured such that the porosity degree, in other words the size of the pores varies between the first end 7 and the second end 8. This makes it possible to actively steer and control an even and optimal flow through the entire evaporator. One alternative is that the pores are narrower and consequently have a smaller size proximate to the first end 7, i.e. the closer they are to the first end 7 than the size of the pores located proximate to the second end 8, i.e. the closer they are to the second end 8. In this way more resistance is caused for the first fluid at the first end 7 which encourages the first fluid to flow towards the second 8 along the compensation chamber 2. Such a variation in the porosity degree is easy to obtained when the manufacturing is made by 3D printing, as previously explained.

    [0015] Figure 3 is an outside view of the cooling apparatus 3. From the shape of the housing 4 illustrated in Figure 3, it can be seen that the cooling apparatus 3 comprises a first section 18 containing the base plate 10, the electric component 11, the evaporator 1 and the compensation chamber 2. A second section 19 of the cooling apparatus 3 comprises the condenser 14 and flow channels 21 for a second fluid 36. The flow channels 32 allow the second fluid 36, such as air, to flow through the second section 19 of the cooling apparatus 3, from an inlet in the bottom part of the housing 4 to an outlet in a roof 20 of the housing 4. Naturally the flow direction may be different in other implementations. The flow channels 32 are in thermal contact with the condenser 14 for receiving heat dissipated from the first fluid.

    [0016] Figure 4 is a simplified view of the cooling apparatus illustrating details of the cooling apparatus 3 with the housing 4 removed. In Figure 4 the lower parts of the cooling apparatus 3 are not shown. However, these lower parts are implemented as illustrated in Figure 2. The upper part of the cooling apparatus 3 as illustrated in Figure 4 together with the lower part of the cooling apparatus as illustrated in Figure 2 form a CLHP. As such a CLHP is orientation independent the illustrated apparatus can be installed and utilized in any orientation, even upside down with the condenser 14 at the bottom with respect to the working direction of the earth's gravity, and despite of this a sufficient circulation of the first fluid to achieve efficient cooling is obtained.

    [0017] In Figure 4 the base plate 10 does not extend all the way to the first end of the 7 evaporator 1 in order to more clearly illustrate the first end of the evaporator in this figure. However, in many implementations it is advantageous to utilize a base plate extending all the way to the first end of the evaporator 7. The base plate 10 may even extend beyond the first end 7 of the evaporator 1 such that it makes contact or almost makes contact with the inner surface of the roof 20.

    [0018] Instead of providing a fluid path between the first end 7 of the evaporator 1 and the first end 21 of the condenser 14 via pipes, a chamber 22 is provided in the first end of the apparatus 3. In the invention this chamber 22 which is delimited by the housing 4, the evaporator and the condenser is illustrated in Figure 3 and the location of it is indicated in Figure 4. This chamber 22 provides a fluid path between the first section 18 containing the evaporator 1 and the second section 19 containing the condenser. An advantage in using such a chamber 22 to provide a fluid path between the first end 7 of the evaporator 1 and the first end 21 of the condenser 14 is that pressure losses are minimized. The chamber 22 may easily be dimensioned to be sufficiently large, such that it provides a cross-sectional flow area which is of approximately the same size or larger than the combined cross-sectional flow area of the evaporator channels 6, for instance. The first end 21 of the condenser 14 is at the location where fluid can enter the condenser from the chamber 22.

    [0019] In the illustrated embodiment, the condenser 14 is implemented to include a plurality of assemblies 24. Each assembly includes a pair of plates 25 with spacer elements 26 arranged along the edges of the plates 25 to keep the plates at a distance from each other. Consequently a first gap is provided between each pair of plates 25. This first gap which is limited by the plates 25 and the spacer elements 26 forms a condenser channel 23. In order to enhance the surface area coming into contact with the first fluid, offset strips 27, fins or any other condensation enhancement structure may be arranged in this first gap, as illustrated in Figure 4. An advantage which may be obtained with the offset strips 27 or a similar structure is that these break down the liquid layer decreasing the condensation thermal resistance which is proportional to the liquid film thickness.

    [0020] A second gap 31 in the first front end of each assembly 24 (by removal of a part of the space elements 26) allows first fluid from the first end 7 of the evaporator 1 to enter the condenser channels 23 provided as the first gaps between by the plates 25, the spacer elements 26 and the offset strips 27. Similarly a third gap 28 in the second front end of each assembly 24 (by removal of a part of the spacer elements 26) allows the first fluid to exit the condenser channels 23 of the condenser 14 and to enter the compensation chamber 2.

    [0021] The flow channels 32 are provided with fins 33 and extend through the condenser 14 for allowing the second fluid 36 to pass through the condenser 14. In the illustrated embodiment these flow channels 32 are located between the assemblies 24 which are separated from each other by spacer bars 30.

    [0022] The illustrated cooling apparatus may be manufactured of a 3D printed evaporator, metal plates and bars which are cut into suitable dimensions and attached to each other by brazing, soldering or similar techniques, for instance. In praxis it is possible to mechanically connect the components of the cooling apparatus to each other during a single brazing step in an oven, for instance. Due to this the manufacturing costs of the apparatus can be kept low and the apparatus having superior thermal performance can be manufactured into desired dimensions to replace conventional heat sinks in existing electric cabinets.

    [0023] Figures 5 to 8 illustrate dimensioning of the cooling apparatus illustrated in Figures 1 to 4.

    [0024] In order to work efficiently enough capillary pressure must be generated to pump the first fluid through the evaporator, the first fluid must flow through the pores with as low friction pressure losses as possible and the evaporator must allow the heat to diffuse efficiently throughout the mass of the porous structure. In order to meet these requirements and obtain an efficient cooling apparatus, appropriate dimensioning of the evaporator is needed.

    [0025] Figure 5 illustrates the dependency between the pressure and the pore diameter. In Figure 6 graph 34 illustrates the dependency between the porosity and the pressure while graph 35 illustrates the dependency between the porosity and the thermal conductivity. Figure 7 illustrates the dependency between the number of channels N (the channels N are illustrated in Figure 1) and the pressure. Figure 8 illustrates the dependency between the channel diameter and the pressure.

    [0026] For first fluids commonly used in cooling apparatuses for electric devices a suitable dimensioning of the evaporator is about 75% porosity, a pore size of about 15 µm, the number of channels N: 50 and a channel diameter of about 1.5 mm X 1.5 mm. With such dimensions a suitable first fluid to use is R245fa (1,1,1,3,3-pentafluoropropane), for instance.

    [0027] Figure 9 illustrates an alternative embodiment of an evaporator. The embodiment of Figure 9 is very similar to the one previously explained. Therefore the embodiment of Figure 9 will be explained mainly by pointing out the differences to the previous embodiments.

    [0028] In Figure 9 illustrates an end view of the evaporator 1' and the base plate 10 attached to the first surface 9 of the evaporator 1'. From Figure 9 it can be seen that the evaporator channels 6 opening up into the end surface of the evaporator 1' are arranged differently than in the previous embodiments. The uppermost layer of the evaporator channels 6 are arranged as grooves in the first surface 9 of the evaporator 1', while the lower layer of evaporator channels 6 is embedded at a location between the first surface 9 and the second surface 16. A consequence of this is that the contact area between the base plate 10 and the evaporator 9 is smaller than in the previous embodiment. This is cause by the fact that the grooves in the upper surface 9 reduces the contact area and consequently also reduces thermal conduction of heat from the base plate to the evaporator.


    Claims

    1. A cooling apparatus (3) comprising:

    a base plate (10) for receiving a heat load from one or more electric components (11),

    an evaporator (1) with a first surface (9) in thermal contact with a surface of the base plate (10) for transferring said heat load into a first fluid in the evaporator (1) in an operating state of the cooling apparatus (3), wherein the evaporator (1) comprises a porous structure having capillary pores (5),

    a condenser (14) for receiving first fluid from a first end (7) of the evaporator (1) and for dissipating heat from the first fluid, and

    a compensation chamber (2) extending along a second surface (16) of the evaporator (1), which is an opposite surface to the first surface (9), the compensation chamber (2) receiving first fluid from the condenser (14) such that pores (5) opening up into the second surface (16) of the evaporator (1) are provided with first fluid,

    wherein the cooling apparatus (3) is a capillary loop heat pipe, and

    wherein the porous structure of the evaporator (1) is a porous aluminum structure having capillary pores (5) and larger sized evaporator channels (6) extending through the evaporator (1) between a second end (8) and the first end (7) of the evaporator, characterized in that

    the evaporator channels (6) are embedded in the evaporator (1) at a location between the first surface (9) and the second surface (15) and arranged in more than one layer such that each layer includes a plurality of evaporator channels (6), and

    the cooling apparatus (3) comprises a chamber (22) in a first end of the apparatus which is in fluid communication with the first end (7) of the evaporator (1) and with a first end (21) of the condenser (14) for passing first fluid from the evaporator to the condenser with minimized pressure losses, a cross-sectional flow area of the chamber (22) is of similar size or larger than the combined cross-sectional flow area of all the evaporator channels (6), said chamber is delimited by the housing (4), the evaporator and the condenser.


     
    2. The cooling apparatus according to claim 1, wherein the apparatus comprises a flow channel (32) for a second fluid (36) which is in thermal contact with the condenser (14) for receiving heat dissipated from the first fluid.
     
    3. The cooling apparatus according to one of claims 1 to 2, wherein the second fluid (16) is air and the flow channel (32) is provided with fins (30) for dissipating heat into air flowing through the flow channel (32).
     
    4. The cooling apparatus according to one of claims 1 to 3, wherein the condenser (14) is provided with assemblies (24) comprising a pair of plates (25) with spacer elements (26) separating the plates from each other in order to provide condenser channels (23) which are limited by the plates (25) and the spacer elements (26).
     
    5. The cooling apparatus according to one of claims 1 to 4, wherein the size of the pores (5) is 1 to 100 µm and the diameter of the evaporator channels (6) are 0.5 to 5 mm.
     
    6. The cooling apparatus according to one of claims 1 to 5, wherein the size of the pores varies between the first end (7) of the evaporator and the second end of the evaporator (8).
     
    7. The cooling apparatus according to claim 6, wherein the size of the pores proximate to the first end (7) is smaller than the size of the pores proximate to the second end (8).
     
    8. The cooling apparatus according to claim 6, wherein the size of the pores proximate to the first end (7) is larger than the size of the pores proximate to the second end (8).
     
    9. A power module comprising one or more electric components (11) thermally connected to the base plate (10) of a cooling apparatus (3) according to any one of claims 1 to 8.
     
    10. A method for manufacturing a cooling apparatus (3), characterized in that the method comprises:

    producing an evaporator (1) having a capillary porous structure with pores (5) and a plurality of larger sized evaporator channels (6) embedded in the evaporator (1) at a location between a first surface (9) and a second surface (15) of the evaporator (1) and arranged in more than one layer such that each layer includes a plurality of evaporator channels (6) extending through the evaporator (1) between a second (8) and a first end (7) of the evaporator by utilizing a 3D printer,

    providing a compensation chamber (2) to extend along a second surface (16) of the evaporator (1) for supplying first fluid to the evaporator via pores (5) opening up into the second surface (16), and

    providing fluid paths from said evaporator (1) and said compensation chamber (2) to a first (21) and respectively second end (15) of a condenser (14) for passing evaporated first fluid from the evaporator (1) to the condenser (14) and for passing condensed first fluid from the condenser (14) to the compensation chamber (2) in an operating state of the cooling apparatus (3), and

    providing chamber (22) in a first end of the apparatus which is in fluid communication with the first end (7) of the evaporator (1) and with a first end (21) of the condenser (14) for passing first fluid from the evaporator to the condenser with minimized pressure losses, a cross-sectional flow area of the chamber (22) is of similar size or larger than the combined cross-sectional flow area of all the evaporator channels (6), said chamber is delimited by the housing (4), the evaporator and the condenser.


     
    11. The method according to claim 10, wherein the components of the cooling apparatus (3) are mechanically connected to each other during a single brazing step.
     
    12. The method according to claim 10 or 11, wherein the cooling apparatus (3) is a cooling apparatus according to any one of claims 1 to 8.
     


    Ansprüche

    1. Kühlvorrichtung (3), umfassend:

    eine Grundplatte (10) zum Empfangen einer Wärmelast von einer oder mehreren elektrischen Komponenten (11),

    einen Verdampfer (1) mit einer ersten Oberfläche (9) in thermischem Kontakt mit einer Oberfläche der Grundplatte (10) zum Übertragen der Wärmelast in ein erstes Fluid im Verdampfer (1) in einem Betriebszustand der Kühlvorrichtung (3), wobei der Verdampfer (1) eine poröse Struktur mit Kapillarporen (5) umfasst,

    einen Kondensator (14) zur Aufnahme des ersten Fluids von einem ersten Ende (7) des Verdampfers (1) und zur Wärmeabfuhr aus dem ersten Fluid, und

    eine Ausgleichskammer (2), der sich entlang einer zweiten Oberfläche (16) des Verdampfers (1) erstreckt, die eine der ersten Oberfläche (9) gegenüberliegende Oberfläche ist, wobei die Ausgleichskammer (2) ein erstes Fluid vom Kondensator (14) erhält, so dass Poren (5), die sich in die zweite Oberfläche (16) des Verdampfers (1) öffnen, mit einem ersten Fluid versehen werden,

    wobei die Kühlvorrichtung (3) ein Kapillarschleifenwärmerohr ist, und

    wobei die poröse Struktur des Verdampfers (1) eine poröse Aluminiumstruktur mit Kapillarporen (5) und größeren Verdampferkanälen (6) ist, die sich durch den Verdampfer (1) zwischen einem zweiten Ende (8) und dem ersten Ende (7) des Verdampfers erstrecken, dadurch gekennzeichnet, dass

    die Verdampferkanäle (6) an einer Stelle zwischen der ersten Oberfläche (9) und der zweiten Oberfläche (15) in den Verdampfer (1) eingebettet und in mehr als einer Schicht angeordnet sind, so dass jede Schicht eine Mehrzahl von Verdampferkanälen (6) aufweist, und

    die Kühlvorrichtung (3) eine Kammer (22) in einem ersten Ende der Vorrichtung umfasst, die in Fluidverbindung mit dem ersten Ende (7) des Verdampfers (1) und mit einem ersten Ende (21) des Kondensators (14) steht, um das erste Fluid mit minimierten Druckverlusten vom Verdampfer zum Kondensator zu leiten, wobei eine Querschnittsströmungsfläche der Kammer (22) eine ähnliche Größe oder größer als die kombinierte Querschnittsströmungsfläche von allen Verdampferkanälen (6) hat, wobei die Kammer durch das Gehäuse (4), den Verdampfer und den Kondensator begrenzt ist.


     
    2. Kühlvorrichtung nach Anspruch 1, wobei die Vorrichtung einen Strömungskanal (32) für ein zweites Fluid (36) umfasst, das in Thermokontakt mit dem Kondensator (14) steht, um vom ersten Fluid verstreute Wärme aufzunehmen.
     
    3. Kühlvorrichtung nach einem der Ansprüche 1 bis 2, wobei das zweite Fluid (16) Luft ist, und der Strömungskanal (32) mit Rippen (30) zum Streuen von Wärme in die durch den Strömungskanal (32) strömende Luft versehen ist.
     
    4. Kühlvorrichtung nach einem der Ansprüche 1 bis 3, wobei der Kondensator (14) mit Baugruppen (24) versehen ist, die ein Plattenpaar (25) mit Abstandshalterelementen (26) umfassen, die die Platten voneinander trennen, um Kondensatorkanäle (23) bereitzustellen, die durch die Platten (25) und die Abstandshalterelemente (26) begrenzt sind.
     
    5. Kühlvorrichtung nach einem der Ansprüche 1 bis 4, wobei die Größe der Poren (5) 1 bis 100 µm und der Durchmesser der Verdampferkanäle (6) 0,5 bis 5 mm beträgt.
     
    6. Kühlvorrichtung nach einem der Ansprüche 1 bis 5, wobei die Größe der Poren zwischen dem ersten Ende (7) des Verdampfers und dem zweiten Ende (8) des Verdampfers variiert.
     
    7. Kühlvorrichtung nach Anspruch 6, wobei die Größe der Poren in der Nähe des ersten Endes (7) kleiner als die Größe der Poren in der Nähe des zweiten Endes (8) ist.
     
    8. Kühlvorrichtung nach Anspruch 6, wobei die Größe der Poren in der Nähe des ersten Endes (7) größer als die Größe der Poren in der Nähe des zweiten Endes (8) ist.
     
    9. Leistungsmodul, umfassend eine oder mehrere elektrische Komponenten (11), das thermisch mit der Grundplatte (10) einer Kühlvorrichtung (3) nach einem der Ansprüche 1 bis 8 verbunden ist.
     
    10. Verfahren zur Herstellung einer Kühlvorrichtung (3), dadurch gekennzeichnet, dass das Verfahren Folgendes umfasst:

    Herstellen eines Verdampfers (1) mit einer porösen kapillaren Struktur mit Poren (5) und einer Mehrzahl von größeren Verdampferkanälen (6), die in den Verdampfer (1) an einer Stelle zwischen einer ersten Oberfläche (9) und einer zweiten Oberfläche (15) des Verdampfers (1) eingebettet und in mehr als einer Schicht angeordnet sind, so dass jede Schicht eine Mehrzahl von Verdampferkanälen (6) aufweist, die sich durch den Verdampfer (1) zwischen einem zweiten (8) und einem ersten Ende (7) des Verdampfers unter Verwendung eines 3D-Druckers erstrecken,

    Bereitstellen einer Ausgleichskammer (2), der sich entlang einer zweiten Oberfläche (16) des Verdampfers (1) erstreckt, um dem Verdampfer ein erstes Fluid über Poren (5) zuzuführen, die sich in die zweite Oberfläche (16) öffnen, und

    Bereitstellen von Fluidwegen vom Verdampfer (1) und der Ausgleichskammer (2) zu einem ersten (21) beziehungsweise zweiten Ende (15) eines Kondensators (14) zum Durchleiten von verdampftem erstem Fluid vom Verdampfer (1) zum Kondensator (14) und zum Durchleiten von kondensiertem erstem Fluid vom Kondensator (14) zur Ausgleichskammer (2) in einem Betriebszustand der Kühlvorrichtung (3), und

    Bereitstellen einer Kammer (22) in einem ersten Ende der Vorrichtung, der in Fluidverbindung mit dem ersten Ende (7) des Verdampfers (1) steht, und mit einem ersten Ende (21) des Kondensators (14) zum Durchleiten des ersten Fluids vom Verdampfer zum Kondensator mit minimierten Druckverlusten, wobei eine Querschnittsströmungsfläche der Kammer (22) von ähnlicher Größe oder größer als die kombinierte Querschnittsströmungsfläche von allen Verdampferkanälen (6) aufweist, wobei die Kammer durch das Gehäuse (4), den Verdampfer und den Kondensator begrenzt ist.


     
    11. Verfahren nach Anspruch 10, wobei die Komponenten der Kühlvorrichtung (3) mit einem einzigen Lötschritt mechanisch miteinander verbunden werden.
     
    12. Verfahren nach Anspruch 10 oder 11, wobei die Kühlvorrichtung (3) eine Kühlvorrichtung nach einem der Ansprüche 1 bis 8 ist.
     


    Revendications

    1. Dispositif de refroidissement (3) comprenant :

    une plaque de base (10) pour recevoir une charge thermique en provenance d'un ou de plusieurs composants électriques (11),

    un évaporateur (1) avec une première surface (9) en contact thermique avec une surface de la plaque de base (10) pour transférer ladite charge thermique dans un premier liquide dans l'évaporateur (1) dans un état opérationnel du dispositif de refroidissement (3), dans lequel l'évaporateur (1) comprend une structure poreuse ayant des pores capillaires (5),

    un condensateur (14) pour recevoir un premier liquide provenant d'une première extrémité (7) de l'évaporateur (1) et pour dissiper de la chaleur provenant du premier liquide, et

    une chambre de compensation (2) s'étendant le long d'une seconde surface (16) de l'évaporateur (1), qui est une surface opposée à la première surface (9), la chambre de compensation (2) recevant un premier liquide provenant du condensateur (14) de telle sorte que des pores (5) s'ouvrant à l'intérieur de la seconde surface (16) de l'évaporateur (1) sont fournis avec le premier liquide,

    dans lequel le dispositif de refroidissement (3) est un tuyau de chaleur à boucle capillaire, et

    dans lequel la structure poreuse de l'évaporateur (1) est une structure en aluminium poreux ayant des pores capillaires (5) et des canaux d'évaporateurs plus grands (6) s'étendant à travers l'évaporateur (1) entre une seconde extrémité (8) et la première extrémité (7) de l'évaporateur, caractérisé en ce que

    les canaux d'évaporateur (6) sont intégrés dans l'évaporateur (1) à une position entre la première surface (9) et la seconde surface (15) et disposés dans plusieurs couches de telle sorte que chaque couche comprend une pluralité de canaux d'évaporateur (6), et

    le dispositif de refroidissement (3) comprend une chambre (22) dans une première extrémité du dispositif qui est en communication fluidique avec la première extrémité (7) de l'évaporateur (1) et avec une première extrémité (21) du condensateur (14) pour transmettre le premier liquide de l'évaporateur au condensateur avec des pertes de pression minimales, une aire d'écoulement en coupe transversale de la chambre (22) a une taille similaire ou plus grande que l'aire d'écoulement en coupe transversale combinée de l'ensemble des canaux d'évaporateur (6), ladite chambre étant délimitée par le logement (4), l'évaporateur et le condensateur.


     
    2. Dispositif de refroidissement selon la revendication 1, dans lequel le dispositif comprend un canal d'écoulement (32) pour un second liquide (36) qui est en contact thermique avec le condensateur (14) pour recevoir de la chaleur dissipée provenant du premier liquide.
     
    3. Dispositif de refroidissement selon l'une quelconque des revendications 1 à 2, dans lequel le second liquide (16) est de l'air et le canal d'écoulement (32) est pourvu d'ailettes (30) pour dissiper la chaleur en de l'air s'écoulant à travers le canal d'écoulement (32).
     
    4. Dispositif de refroidissement selon l'une quelconque des revendications 1 à 3, dans lequel le condensateur (14) est pourvu d'ensembles (24) comprenant une paire de plaques (25) avec des entretoises (26) séparant les plaques les unes des autres afin de fournir des canaux de condensateur (23) qui sont limités par les plaques (25) et les entretoises (26).
     
    5. Dispositif de refroidissement selon l'une quelconque des revendications 1 à 4, dans lequel la taille des pores (5) varie de 1 à 100 µm et le diamètre des canaux d'évaporateur (6) varie de 0,5 à 5 mm.
     
    6. Dispositif de refroidissement selon l'une quelconque des revendications 1 à 5, dans lequel la taille des pores varie entre la première extrémité (7) de l'évaporateur et la seconde extrémité (8) de l'évaporateur.
     
    7. Dispositif de refroidissement selon la revendication 6, dans lequel la taille des pores à proximité de la première extrémité (7) est inférieure à la taille des pores à proximité de la seconde extrémité (8).
     
    8. Dispositif de refroidissement selon la revendication 6, dans lequel la taille des pores à proximité de la première extrémité (7) est supérieure à la taille des pores à proximité de la seconde extrémité (8).
     
    9. Module électrique comprenant un ou plusieurs composants électriques (11) reliés thermiquement à la plaque de base (10) d'un dispositif de refroidissement (3) selon l'une quelconque des revendications 1 à 8.
     
    10. Procédé de fabrication d'un dispositif de refroidissement (3), caractérisé en ce que le procédé comprend les étapes consistant à :

    produire un évaporateur (1) ayant une structure poreuse capillaire avec des pores (5) et une pluralité de canaux d'évaporateur plus grands (6) intégrés dans l'évaporateur (1) à une position entre une première surface (9) et une seconde surface (15) de l'évaporateur (1) et disposés dans plusieurs couches de telle sorte que chaque couche comprend une pluralité de canaux d'évaporateur (6) s'étendant à travers l'évaporateur (1) entre une seconde (8) et une première extrémité (7) de l'évaporateur à l'aide d'une imprimante 3D,

    fournir une chambre de compensation (2) pour s'étendre le long d'une seconde surface (16) de l'évaporateur (1) afin de fournir un premier liquide à l'évaporateur par l'intermédiaire de pores (5) s'ouvrant à l'intérieur de la seconde surface (16), et

    fournir des voies de liquide à partir dudit évaporateur (1) et de ladite chambre de compensation (2) vers une première (21) et respectivement une seconde extrémité (15) d'un condensateur (14) pour transmettre un premier liquide évaporé de l'évaporateur (1) au condensateur (14) et pour transmettre un premier liquide condensé du condensateur (14) à la chambre de compensation (2) dans un état opérationnel du dispositif de refroidissement (3), et

    fournir une chambre (22) dans une première extrémité du dispositif qui est en communication fluidique avec la première extrémité (7) de l'évaporateur (1) et avec une première extrémité (21) du condensateur (14) pour transmettre un premier liquide de l'évaporateur au condensateur avec des pertes de pression minimales, une aire d'écoulement en coupe transversale de la chambre (22) étant de taille similaire ou supérieure à l'aire d'écoulement en coupe transversale combinée de l'ensemble des canaux d'évaporateur (6), ladite chambre étant délimitée par le logement (4), l'évaporateur et le condensateur.


     
    11. Procédé selon la revendication 10, dans lequel les composants du dispositif de refroidissement (3) sont reliés mécaniquement les uns au autres pendant une étape unique de brasage.
     
    12. Procédé selon la revendication 10 ou 11, dans lequel le dispositif de refroidissement (3) est un dispositif de refroidissement selon l'une quelconque des revendications 1 à 8.
     




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    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description