Cooling device for cooling an electrical device, corresponding cooling system and aircraft comprising at least one such cooling system

Abstract

Cooling device for cooling electrical equipment, corresponding cooling system and aircraft comprising at least one such cooling system. The invention relates to a device (1) for cooling electrical equipment (2), a corresponding cooling system and an aircraft. The device (1) comprises: a circulation channel (11) containing a flow (110) of a biphase coolant (111); a thermally conductive wall (13) intended to separate the channel (11) from the electrical equipment; at least one fin (15) disposed within the channel (11) and extending from the wall (13), each fin (15) being configured to be in a position proximate to the wall when the temperature of the fin (15) is lower than a predetermined temperature and in a distant position when the temperature of the fin (15) is greater than or equal to the predetermined temperature. This arrangement makes it possible to effectively cool the electrical equipment without having to reduce the power of the electrical equipment with very high heat loss.

Description

Technical Field

[0001] The present invention relates to a cooling device for electrical and / or electronic equipment (hereinafter referred to in the specification in combination as the term "electrical equipment"). The present invention more particularly relates to cooling such equipment by circulation of a two-phase coolant. The present invention also relates to a cooling system comprising a cooling device and an electrical equipment, and an aircraft comprising at least one such system. Background Art

[0002] In the context of the electrification of aircraft, energy demand has increased significantly over the past few years. In fact, both the electrical systems related to the flight of the aircraft (flight controls, computers, flight computers, etc.) and the electrical systems dedicated to the passengers (pressurization system, ventilation system, digital entertainment system, etc.) have increased the power to be delivered to ensure optimal operation of the aircraft in all conditions.

[0003] However, in order to meet these increasing power demands, it is not always possible to increase the size of the electrical equipment, since, among other things, volume and weight limits must be observed.

[0004] In order to try to comply with the restrictions on the size of electrical equipment, one solution consists in increasing the operating temperature of the power electronics of the equipment, which however does produce very significant heat losses. To remedy this, conventional single-phase coolant systems have been Figure 1a and Figure 1b 9, which is also referred to as a phase change cooling system. Therefore, the coolant 93 circulating around or above the electrical device 92 will change phase, that is, the coolant 93 will change from liquid 93a to gas 93b when it contacts the wall 921 of the circuit of the electrical device 92.

[0005] A disadvantage of this solution is that in the event that the electrical device 92 generates an excessive heat flux 91 , in other words in the event of an excessive heat flux, called critical heat flux (CHF), the wall 921 risks drying out, e.g. Figure 1b If the wall 921 dries out, that is, if the wall 921 is no longer in contact with the liquid fluid 93a, the temperature of the circuit of the electrical device 92 will only increase exponentially. Therefore, the risk of degradation or even destruction of the electrical device 92 is very high.

[0006] To cope with this situation, it is known to reduce the power of the electrical equipment at least temporarily in order to reduce the temperature of the circuit. Now, it can be proved that such a power reduction is impossible or even dangerous, for example, during the take-off phase of the aircraft or during certain maneuvers.

[0007] Therefore, it is necessary to provide a solution for cooling electrical equipment, in particular electrical equipment of an aircraft, so as to at least partially remedy the above-mentioned disadvantages. Preferably, such a solution must be effective, easy to implement and small in size. Summary of the invention

[0008] One object of the present invention is to propose a device for cooling electrical equipment that is easy to implement and that in particular complies with the volume constraints associated with aircraft.

[0009] To this end, a device for cooling an electrical device is proposed, the electrical device comprising a circuit, the temperature of the circuit increasing between a nominal operation of the electrical device and a critical operation, in which the circuit delivers a nominal power and in which the circuit delivers a critical power greater than the nominal power, the device comprising:

[0010] - a circulation channel containing a flow of a coolant, said coolant being a two-phase fluid having a liquid phase and a gas phase,

[0011] - a thermally conductive wall intended to separate said channel from said circuit and intended to be in contact with said circuit,

[0012] - at least one fin disposed in the channel and extending from the wall, each fin comprising a proximal end fixed to the wall and a distal end opposite the proximal end, each fin being movable between an approximate position in which the distal end is proximal to the wall and a distal position in which the distal end is distal to the wall and at least partially forms an obstacle to the flow of the coolant.

[0013] The at least one fin is configured to be in the approximate position when the temperature of the fin is lower than a predetermined temperature, and to be in the distal position when the temperature of the fin is greater than or equal to the predetermined temperature.

[0014] According to the present invention, the predetermined temperature is equal to the phase transition temperature of the coolant.

[0015] The cooling device of the invention thus makes it possible to cool an electrical device efficiently without having to reduce the power of the electrical device in the event of very high heat losses.

[0016] According to a particular aspect of the invention, the at least one fin comprises a first surface facing the wall when the at least one fin is in the approach position, and a second surface opposite to the first surface. In the remote position, the at least one fin is inclined relative to the wall, and the flow of the coolant circulates toward the second surface of the at least one fin.

[0017] According to a particular aspect of the invention, the at least one fin comprises a first part made of metal and a second part made of a shape memory alloy.

[0018] According to another particular aspect of the invention, the second member comprises a first portion fixed to the wall and a second portion fixed to the first portion at an elastically deformable joint, the second portion being movable relative to the wall between an approached position and a remote position.

[0019] According to yet another particular aspect of the present invention, the first component at least partially covers the second portion.

[0020] According to a particular aspect of the invention, the metal making up the first component is selected from: copper, aluminum, gold or inconel®, and the shape memory alloy making up the second component is selected from: nitinol (nickel-titanium alloy), copper-zinc-aluminum alloy, copper-aluminum-nickel alloy or iron-manganese-silicon alloy.

[0021] According to a particular aspect of the invention, the length of the second portion of the fin is configured so that when the at least one fin is in the remote position, when the wall is separated from the liquid phase by the gas phase of the coolant, at least the distal end of the fin reaches the liquid phase.

[0022] According to a particular aspect of the invention, the device comprises a plurality of fins arranged on the wall in rows, staggered or in a combination of these arrangements.

[0023] The invention also relates to a cooling system comprising an electrical device and a device as described above, wherein a wall of the device is in contact with a circuit of the electrical device.

[0024] Furthermore, the invention relates to an aircraft comprising at least one cooling system as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features of the present invention will become more apparent upon reading the following description of exemplary embodiments given with reference to the accompanying drawings, in which:

[0026] Figure 1a A two-phase cooling system according to the prior art is schematically illustrated when the electrical equipment to be cooled is in a nominal operating state;

[0027] Figure 1b Schematic showing what happens when the electrical equipment to be cooled is operating at full power. Figure 1a system;

[0028] Figure 2 A cooling system according to the invention is schematically illustrated when the electrical equipment to be cooled is in nominal operation;

[0029] Figure 3 Schematic showing what happens when the electrical equipment to be cooled is operating at full power. Figure 2 system;

[0030] Figure 4 Schematically and independently illustrating a cooling device according to the invention when the electrical equipment to be cooled is operated at full power; and

[0031] Figure 5 An aircraft is shown which comprises a plurality of cooling systems according to the invention. DETAILED DESCRIPTION

[0032] Figures 2 to 4 A cooling device 1 according to the invention is schematically illustrated. The device 1 is intended to cool an electrical device 2, preferably an electrical device intended to be embedded in a Figure 5 The electrical equipment 2 in the aircraft A shown is cooled.

[0033] The electrical device 2 includes a circuit 20, such as a power electronic circuit, which generates a heat flux 200 when the circuit operates. Due to the heat flux 200, the temperature T1 of the circuit 20 is variable according to the operation of the circuit 20. Therefore, when the power delivered by the circuit 20 increases, the temperature T1 of the circuit 20 increases. More specifically, the temperature T1 of the circuit 20 increases between the nominal operation of the electrical device 2, in which the circuit 20 delivers a nominal power P1, and the critical operation, in which the circuit 20 delivers a critical power P2 greater than the nominal power P1.

[0034] For example, the nominal power P1 comprises a range of power values ​​corresponding to the nominal operation of the electrical device 2. The critical power P2 may be a power value above which the electrical device 2 is considered to be operating at full power.

[0035] When the critical power P2 is reached, the temperature T1 of the circuit 20 reaches a critical value. Starting from this critical temperature, the heat flux 200 is called the critical heat flux (abbreviated CHF).

[0036] The cooling device 1 of the invention, intended to cool such an electrical device 2, comprises a circulation channel 11 containing a flow 110 of a coolant 111. According to the invention, the coolant 111 circulating in the channel 11 is a two-phase fluid, that is, within the operating temperature range of the circuit 20, the coolant 111 has two phases, namely a liquid phase 111a and a gas phase 111b.

[0037] The device 1 also comprises a wall 13, which is arranged between the channel 11 and the circuit 20 of the electrical device 2 and separates the channel 11 from the circuit 20. The wall 13 is thermally conductive and is in contact with the circuit 20 so as to promote the heat exchange from the circuit 20 to the flow 110, which makes it possible to cool the circuit 20. In a variant, it is conceivable that the wall 13 is constituted by the wall of the electrical device 2.

[0038] For example, the wall 13 is made of copper, or of aluminum, or of gold, or of Inconel® (a superalloy consisting mainly of nickel, chromium, iron, magnesium and titanium), or of any other sufficiently thermally conductive metal (for example a metal having a thermal conductivity greater than 30 W / mK).

[0039] According to the invention, the device 1 comprises at least one elastic fin 15 arranged in the channel 11. Figures 2 to 4 In the example shown schematically, a single fin 15 is presented, and the rest of the description is based on this example. It is easy to understand that the device 1 can implement multiple fins 15, and when the device 1 includes multiple fins 15, the following description of the fin 15 can apply to all fins 15.

[0040] The fin 15 extends from the wall 13. More specifically, the fin 15 includes a proximal end 151 fixed to the wall 13 and a distal end 153 opposite to the proximal end 151. The fin 15 is movable between an approach position, in which the distal end 153 approaches the wall 13 (in other words, the fin 15 is lowered and extends generally parallel to the wall 13), and a distal position, in which the distal end 153 is away from the wall 13 (in other words, the fin 15 is inclined relative to the wall 13). When the fin 15 is in the distal position, the fin 15 at least partially forms an obstacle to the flow 110 of the coolant 111, thereby generating disturbances in the flow 110 and increasing the heat exchange between the circuit 20 and the coolant 111.

[0041] More specifically, the fin 15 is configured to be in the close position when the temperature T3 of the fin 15 is lower than the predetermined temperature Tref, and to be in the raised position when the temperature T3 of the fin 15 is greater than or equal to the predetermined temperature Tref.

[0042] The close position of the fins 15 corresponds to a state in which the electrical device 2 is in nominal operation. Therefore, the power P1 delivered by the circuit 20 of the electrical device 2 is then considered to be nominal. Therefore, the temperature T1 of the circuit 20 is also within the nominal operating value. Therefore, the heat exchange between the circuit 20 and the coolant 111 of the flow 110 is sufficient to cool the wall 13. In this case, the liquid phase 111a of the coolant 111 thus covers the entire wall 13. In other words, the gas phase 111b is not in contact with the wall 13, so the wall 13 is completely wet. Therefore, the cooling of the electrical device 2 is effective.

[0043] When the circuit 20 delivers a higher power reaching or exceeding the critical power P2, the temperature T1 of the circuit 20 increases. Therefore, the increase in the temperature T1 of the circuit 20 will increase the temperature T2 of the coolant 111, and thus increase the temperature T3 of the fin 15, until the temperature T3 of the fin 15 reaches and may exceed the predetermined temperature Tref.

[0044] According to one embodiment, the predetermined temperature Tref substantially corresponds to the phase change temperature of the coolant 111. Thus, when the predetermined temperature Tref is reached, the coolant 111 will change phase so that the volume of the liquid phase 111a decreases and the volume of the gas phase 111b increases. Furthermore, due to the capillary action of the coolant 111, the gas phase 111b will replace the liquid phase 111a and will at least partially cover the wall 13. Thus, where the liquid phase 111a no longer covers the wall 13, the wall 13 will dry out and the temperature T1 of the circuit 20 will increase exponentially. In this case, the wall 13 is therefore at least partially separated from the liquid phase 111a by the gas phase 111b.

[0045] In the prior art, this situation is usually critical and requires reducing the power of the circuit 20 to allow the temperature T1 of the circuit 20 to decrease, and therefore the temperature T2 of the coolant 111 to also decrease, so that the wall 13 is again covered with the liquid phase 111a. Now, this need to reduce the power delivered by the circuit 20 is not satisfied.

[0046] According to the present invention, the fin 15 is configured to be in the remote position when the temperature T3 of the fin 15 reaches or exceeds the predetermined temperature Tref, that is, when the temperature T3 of the fin 15 is greater than or equal to the predetermined temperature Tref. Assuming that the predetermined temperature Tref is equal to the phase change temperature of the coolant 111, when the coolant 111 changes phase, the fin 15 generally changes from the close position to the remote position. In fact, since the fin 15 is bathed in the coolant 111 (that is, the fin 15 is in direct contact with the coolant 111), the temperature T3 of the fin 15 is generally the same as the temperature T2 of the coolant 111. However, when the temperature T1 of the circuit 20 changes suddenly, a relatively small deviation between the temperature T2 of the coolant 111 and the temperature T3 of the fin 15 of between five and ten degrees can be observed (depending on the coolant used and the roughness of the fin 15). When the temperature T1 of the circuit 20 changes little or not, the temperature T3 of the fin 15 tends to be equal to the temperature T2 of the coolant 111.

[0047] As mentioned above, when the fins 15 are in the remote position, the electrical device 2 is considered to be in its critical operation. Therefore, the temperature T2 of the coolant 111 is therefore equal to or greater than the predetermined temperature Tref. Therefore, the liquid phase 111a of the coolant 111 is no longer at least partially in contact with the wall 13, so that the wall 13 dries out. Depending on the temperature T2 of the coolant 111, and therefore on the phase change of the coolant 111, the wall 13 may be completely dry (that is to say completely covered by the gas phase 111b) or partially dry (that is to say a part of the wall 13 is covered by the liquid phase 111a and another part is covered by the gas phase 111b).

[0048] The displacement of the fins 15 from the close position to the remote position away from the wall 13 makes it possible to generate disturbances in the flow 110 of the coolant 111, which makes it possible to increase the heat exchange and thus ensure the heat transfer between the wall 13 and the coolant 111. Thus, the circuit 20 can continue to operate at full power without overheating that could cause obstacles to the correct operation of the electrical device 2.

[0049] In the embodiment shown, the fin 15 comprises a first surface 150a which faces the wall 13 when the fin 15 is in the approach position. The fin 15 has a second surface 150b which is opposite to the first surface 150a and which is situated on one side of the channel 11 when the fin 15 is in the approach position. In the remote position, that is to say when the fin 15 is inclined relative to the wall 13, or in other words when the fin 15 is upright, the flow 110 of the coolant 111 circulates towards the second surface 150b of the fin 15. In this way, when the temperature T3 of the fin 15 is greater than or equal to the predetermined temperature Tref, the fin 15 can generate disturbances in the flow 110. When the temperature T3 of the fin 15 decreases and returns to below the predetermined temperature Tref, the fin 15 must then return to the approach position. With this arrangement and this inclination of the fin 15, the flow 110 does not hinder the displacement of the fin 15 to the approach position. On the contrary, the direction of the flow 110 (given by Figure 2 and Figure 3 ) is beneficial to the displacement of the fin 15 from the distant position to the close position.

[0050] according to Figure 4 In the particular aspect shown in , the fin 15 is bimetallic and is composed of at least one shape memory material. More specifically, the fin 15 includes a first component 155 made of metal and a second component 157 made of a shape memory alloy. The second component 157 made of a shape memory alloy allows elastic deformation of the fin 15. The deformation of the fin 15 is caused by a change in the temperature T3 of the fin 15.

[0051] More specifically, the second component 157 is configured to deform the fin 15 and switch the fin 15 from the close position to the far position when the temperature T3 of the fin 15 (which is substantially equal to the temperature T2 of the coolant 111) reaches or exceeds the predetermined temperature Tref. As long as the temperature T3 of the fin 15 is greater than or equal to the predetermined temperature Tref, the shape memory alloy of the second component 157 keeps the fin 15 in the far position. Therefore, the shape memory alloy of the second component 157 reacts to temperature changes. Therefore, when the temperature T3 of the fin 15 decreases and returns to below the predetermined temperature Tref, the second component 157 will deform again to return to its original form, and since the metal first component 155 operates within its elastic range, the metal first component 155 will assist the fin 15 to return to the close position.

[0052] The second part 157 made of shape memory alloy undergoes a so-called "learning" phase during which the fin learns to change from the close position to the distant position and vice versa at the desired temperature. The first part 155 made of metal makes it possible to assist the displacement from the distant position to the close position.

[0053] Such a fin 15 elastically deformable according to its temperature T3 makes it possible to dispense with the use of a mechanism or actuator for displacing the fin 15 between the approached position to the remote position and vice versa. The device 1 is thus reduced in size, optimized and particularly suitable for implementation, for example, in an aircraft.

[0054] Preferably, the second part 157 made of a shape memory alloy comprises a first portion 157a fixed to the wall 13 and a second portion 157b movable relative to the wall 13. The first portion 157a constituting the base is preferably fixed to the wall 13 in a manner that ensures good heat conduction. For example, the fixing of the first portion 157a to the wall 13 is achieved by brazing, cold welding, laser welding or any other technique that can achieve the same advantages. It is worth noting that the type of fixing is selected according to the material of the wall 13 and the shape memory alloy constituting the second part 157 of the fin 15, the coolant 111 used and the operating temperature T1 of the circuit 20.

[0055] The second member 157 further includes a joint 157c between the first portion 157a and the second portion 157b. The joint 157c constitutes an elastic deformation point of the fin 15 and allows the fin 15 to be displaced between the approach position and the distance position.

[0056] Preferably, the metallic first part 155 at least partially covers the second part 157b of the second part 157 of the fin 15. Preferably, the first part 155 covers the surface of the second part 157b of the second part 157 of the fin 15, and more preferably, the second part 155 covers the second surface 150b of the fin 15. As previously mentioned, and depending in particular on the material of the wall 13 and the shape memory alloy constituting the second part 157 of the fin 15, the coolant 111 used and the operating temperature T1 of the circuit 20, the first part 155 is fixed to the second part 157b of the second part 157 by bonding, cold welding, laser welding or any other technique that can achieve the same advantages. Preferably, the fixing of the first part 155 to the second part 157b is done at each end of the second part 157b, that is to say near the joint 157c and at the distal end 153.

[0057] Preferably, the first component 155 made of metal is selected from: copper, aluminum, gold, inconel®, or any other sufficiently thermally conductive metal (eg a metal with a thermal conductivity greater than 30 W / mK).

[0058] The second component 157 made of shape memory alloy is selected from: Nitinol (nickel-titanium alloy), or copper-zinc-aluminum alloy, or copper-aluminum-nickel alloy, or iron-manganese-silicon alloy.

[0059] Preferably, the second portion 157b of the fin 15 has a length L 1 (exist Figure 4 ), the length is configured so that when the fin 15 is in the remote position, when the wall 13 is separated by the gas phase 111b from the liquid phase 111a, at least the distal end 153 of the fin 15 reaches the liquid phase 111b of the coolant. In other words, during critical operation of the electrical device 2, and therefore when the wall 13 is dry or partially dry (that is to say fully or partially covered by the gas phase 111b), the length L of the second portion 157b of the fin 15 is 1 Sufficient to reach the liquid phase 111a. In this way, the fins 15 will create disturbances in the flow 110 of the coolant 111, which will promote heat exchange. More specifically, when the wall 13 is separated from the liquid phase 111a by the gas phase 111b, the fact that the fins 15 can reach the liquid phase 111a also makes it possible to create disturbances in the liquid phase 111a of the flow 110 to further improve heat exchange. Therefore, the temperature T2 of the coolant 111 decreases faster. Therefore, the same applies to the temperature T1 of the circuit 20.

[0060] According to one embodiment, the length of the second portion 157b of the fin 15 is smaller than the length required for at least the distal end 153 of the fin 15 to reach the liquid phase 111b of the coolant when the fin 15 is in the remote position, when the wall 13 is separated by the gas phase 111b from the liquid phase 111a. In other words, when the wall 13 dries out, the second portion 157b of the fin 15 does not reach the liquid phase 111b. The deployment of the fin 15 forces the fluid to recirculate, which increases the heat exchange, reduces the temperature of the fin 15 and the wall 13, and thus makes it possible to rewet the wall 13. According to this configuration, the effectiveness of the cooling is reduced and the rewetting time is extended compared to a configuration in which the length of the second portion 157b of the fin 15 is sufficient to reach the liquid phase 111b.

[0061] Preferably, the predetermined temperature Tref is equal to the phase change temperature of the coolant 111, and the fin 15 changes from the close position to the far position according to the predetermined temperature Tref, and vice versa. Because the temperature T3 of the fin is substantially equal to the temperature T2 of the coolant 111, once the coolant 111 is overheated and begins to change its phase, the fin 15 stands up to change from the close position to the far position. This position change of the fin 15 makes it possible to promote heat exchange and avoid excessive increase in the temperature T2 of the coolant 111, avoid phase change, and avoid drying of the wall 13. Therefore, this makes it possible to effectively cool the circuit 20, especially by avoiding drying of the wall 13. Therefore, the circuit 20 can continue to operate at full power without worrying that overheating will damage the circuit.

[0062] In an embodiment not represented, it is possible to envisage that the device 1 has a plurality of fins 15 in the channel 11 in order to produce the advantages of turbulence in the flow 110 and thus further improve the heat exchange between the coolant 111 and the circuit 20 .

[0063] The fins 15 can be arranged on the wall 13, for example, in rows or columns, or staggered. These arrangements make it possible to generate disturbances that optimize the heat exchange. With these arrangements, it is also possible to anticipate (that is to say predict) the disturbances that will be generated by the fins 15 and, therefore, the points at which the heat exchange will take place. Thus, the fins 15 can also be arranged at specific points in the channel 11, which correspond to the points in the circuit 20 where the most heat is emitted. Thus, the fins 15 can be placed in areas of the channel 11 where hot spots have been identified. The density of the fins 15 in these areas of the channel 11 where hot spots have been identified can be greater (for example twice) than the density of the fins in other areas of the channel 11 where no hot spots have been identified. Other arrangements are obviously conceivable without departing from the principle of the invention.

[0064] Figure 2 and Figure 3A cooling system 10 according to the invention is presented, comprising a device 1 as previously described and an electrical device 2 to be cooled. In order to allow the electrical device 2 to be cooled, a wall 13 of the device 1 is then placed in contact with the electrical device 2 and preferably with an electrical circuit 20 generating a heat flux 200, to allow a heat exchange between a flow 110 of a coolant 111 and the heat flux generated by the electrical circuit 20.

[0065] Figure 5 An aircraft A is presented that includes at least one cooling system 10 as described above. In this example, several systems 10 are implemented in the aircraft A. The use of such a system 10 in an aircraft advantageously makes it possible to use electrical devices 2 operated at full power for a desired period of time, without having to reduce the power due to untimely heating of the electrical devices 2. In this way, the use of the electrical devices 2 is optimized and adapted in particular to the operational and volume constraints encountered in an aircraft.

Claims

1. A cooling device (1) for cooling an electrical device (2), the electrical device (2) comprising an electric circuit (20), the temperature of the electric circuit increasing between a nominal operation and a critical operation of the electrical device (2), in the nominal operation, the electric circuit (20) delivering a nominal power, in the critical operation, the electric circuit (20) delivering a critical power greater than the nominal power, The cooling device (1) comprises: - a circulation channel (11) containing a flow (110) of a coolant (111) which is a two-phase fluid having a liquid phase (111a) and a gas phase (111b), - a heat-conducting wall (13) intended to separate the circulation channel (11) from the circuit (20) and intended to be in contact with the circuit (20), Characterized in that the cooling device (1) further comprises: - at least one fin (15), the at least one fin being arranged in the circulation channel (11) and extending from the heat-conducting wall (13), each fin (15) comprising a proximal end (151) fixed to the heat-conducting wall (13) and a distal end (153) opposite to the proximal end (151), each fin (15) being movable between an approach position and a remote position, wherein the distal end (153) is close to the heat-conducting wall (13), and the distal end (153) is far away from the heat-conducting wall (13) and at least partially forms an obstacle to the flow (110) of the coolant (111); wherein the at least one fin (15) is configured to be in a close position when the temperature of the fin (15) is lower than a predetermined temperature, and to be in a far position when the temperature of the fin (15) is greater than or equal to the predetermined temperature; And wherein the predetermined temperature is equal to the phase change temperature of the coolant (111).

2. The cooling device (1) according to claim 1, characterized in that: The at least one fin (15) comprises a first surface (150a) facing the heat-conducting wall (13) when the at least one fin (15) is in the close position, and a second surface (150b) opposite to the first surface (150a), wherein, in the remote position, the at least one fin (15) is inclined relative to the heat-conducting wall (13), and wherein the flow (110) of the coolant (111) circulates toward the second surface (150b) of the at least one fin (15).

3. The cooling device (1) according to any one of the preceding claims, characterized in that The at least one fin (15) comprises a first part (155) made of metal and a second part (157) made of a shape memory alloy.

4. The cooling device (1) according to claim 3, characterized in that: The second component (157) includes a first portion (157a) fixed to the heat-conducting wall (13) and a second portion (157b) fixed to the first portion (157a) at an elastically deformable joint (157c), wherein the second portion (157b) is movable relative to the heat-conducting wall (13) between the approach position and the distance position.

5. The cooling device (1) according to claim 4, characterized in that: The first component (155) at least partially covers the second portion (157b).

6. The cooling device (1) according to any one of claims 3 to 5, characterized in that: The metal used to make the first component (155) is selected from: copper, aluminum, gold, or inconel®, and the shape memory alloy used to make the second component (157) is selected from: nitinol, copper-zinc-aluminum alloy, copper-aluminum-nickel alloy, or iron-manganese-silicon alloy.

7. The cooling device (1) according to any one of claims 4 to 6, characterized in that The second portion (157b) has a length (L1) configured such that when the at least one fin (15) is in a remote position, when the heat-conducting wall (13) is separated from the liquid phase (11a) by the gas phase (111b) of the coolant (111), at least the distal end (153) of the fin (15) reaches the liquid phase (111b).

8. Cooling device (1) according to any one of the preceding claims, characterized in that The cooling device comprises a plurality of fins (15), wherein the plurality of fins (15) are arranged on the heat-conducting wall (13) in a row, staggered, or in a combination of the row and staggered arrangements.

9. A cooling system (10), characterized in that: The cooling system comprises an electrical device (2) and a cooling apparatus (1) according to any one of the preceding claims, wherein the heat conducting wall (30) of the cooling apparatus (1) is in contact with the circuit (20) of the electrical device (2).

10. An aircraft (A), characterized in that: The aircraft comprises at least one cooling system (10) according to claim 9.

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