Electronic system equipped with heat-transport fluid cooling circuit

Abstract

To provide an electronic system equipped with a heat-transport fluid cooling circuit.SOLUTION: An electronic system comprises: an external jacket (11); a wall (12) of an internal cavity (13) that is to be cooled; at least one fixed connection fixing the external wall (12) of the internal cavity (13) that is to be cooled to the external jacket; a heat-transport fluid cooling circuit (14) comprising grooves (15) on an external surface (16) of the wall (12) of the internal cavity (13) and a sleeve (17) comprising a flexible portion (18) positioned flush with the external surface (16) of the external wall (12) of the internal cavity (13), thereby forming mini-canals (19) with the grooves (15); a radial extension of the wall (12) of the internal cavity (13) creating connecting points intended to hold the sleeve (17) in place; and a space (20) between the external jacket (11) and the sleeve (17) at the flexible portion (18) of the sleeve (17).SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an electronic system equipped with a heat transport fluid cooling circuit.

Background Art

[0002] The technical field to which the present invention is applied is the field of electronic device technology. The present invention meets the need for a high-performance cooling system for elements subjected to high thermal conditions, particularly for cooling the resonant cavity of a gyrotron.

[0003] In order to limit the thermal expansion of elements of an electron device heated to a critical level with a resonant cavity of a vacuum tube, alloys with low thermal expansion are used in the fabrication of such elements. The devices most affected are gyrotrons and cyclotron autoresonance masers (CARM) operating at millimeter waves at power levels on the order of megawatts.

[0004] This is accompanied by the management of a thermal load of several kW / cm The distance between the heated wall and the heat transport cooling fluid flow plays an important role in improving cooling: the smaller this distance, the greater the degree to which the temperature of the hot spot decreases. Conversely, the minimum allowable thickness is the thickness that provides a vacuum gas density tv. The most effective existing cooling solutions are based on Raschig rings, abbreviated as RR, and porous media heat exchange, abbreviated as PH.

[0005] These techniques are limited by a very important compromise between thermal stress and circumferential expansion and by azimuthal temperature inhomogeneity. The flexibility of the porous medium forces the designer to reach a compromise between heat removal and mechanical stability: if the wall of the element to be cooled is too thin, its thermal expansion may be too large and its mechanical stability may be severely affected. If the wall is too thick, heat exchange is limited by the presence of the thick wall between the heated surface and the heat transport fluid flow: this mode limits heat transfer.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention aims to develop a high-performance cooling system for elements subjected to harsh thermal conditions.

[0007] The proposed invention satisfies the high-efficiency cooling requirements of real electronic and electrical subsystems, systems, and devices that demand ever-increasing cooling capacity in order to minimize thermomechanical deformation. Such deformation of the inner surface of the object being cooled leads to fluctuations in operating frequency and a potential decrease in the output of electronic devices.

[0008] In critical subassemblies of electronic devices, effective cooling must be applied to the anode (grilled tube), collector (klystron and TWT), and cavity (gyrotron and CARM). The best-performing true heat exchangers currently operate using a fluid, often water.

[0009] The purpose of a heat transport fluid is to lower the temperature of a heated surface. Heat is removed by heating the fluid and then flowing this fluid through a cooling circuit. This can be achieved by increasing the efficiency of heat conduction between the heated element and the heat transport fluid, while simultaneously keeping the heat transport fluid as close as possible to the heated surface.

[0010] A well-known implementation involves using small tubes to partially mitigate these drawbacks, but these still generate significant mechanical stress.

[0011] Known cooling solutions using small tubes are affected by several drawbacks, some of which lead to significant mechanical problems with respect to mechanical stress induced in the cavity, far exceeding the acceptable limits that increase the material's tendency to undergo plastic deformation and cracking.

[0012] These solutions often employ two or more elements, generally made from different materials: an internal element surrounded by an external element. Actual tube circuits proposed in the literature assume that, if generated, the tube is implemented as a straight pipe in one block of material or drilled into one of two separate blocks.

[0013] As schematically shown in [Figure 1], in the case of a single block of material, it is a known implementation to employ a network of straight tubes 1 generated in a single block 2. This block 2 is often made of a hollow axially symmetric structure formed by hollow cylindrical bodies having two different outer diameters in three different zones along the axial coordinate: smaller outer diameters in the lateral zones and larger diameters in the central zone containing the tubes 1.

[0014] In this configuration, a specific distance is required between the small tube 1 and the heated wall being cooled, because curvature of the tube's path along the axial coordinates is not permitted. This distance can result in significant thermal resistance.

[0015] Because the milling and drilling of the tube involves a linear machining path, if the element being cooled has a non-cylindrical internal shape (for example, a gyrotron cavity is conical), it is not possible to position the tube 1 at a constant distance (along its length) from the heated wall. This is because the straight tube on the inclined element is at different distances from the cavity at various points along its length. As a result, non-uniform cooling occurs.

[0016] The distance between the heated wall and the heat-transporting fluid flow is limited by the presence of intermediate material required to create the element, and this distance cannot be reduced to a thickness limited by the vacuum density tv.

[0017] In the case of multiple blocks, other solutions are known that are employed by assembling separate elements by brazing or joining these blocks together. Often, only two blocks are needed. The inner block generally has the surface to be heated, and the outer block surrounds the inner block. Using two blocks tends to involve the following disadvantages:

[0018] As shown in [Figure 2], the incomplete contact between blocks 3 and 4 acts as a thermal impedance. When the brazing material or adhesive material 5 is placed in a limited area, for example through the use of a circular extension of the brazing material or adhesive material, the remaining contact between two (or more) blocks 3 and 4 results in incomplete contact, and therefore leads to unavoidable contact thermal resistance.

[0019] As shown in [Figure 3], the presence of the brazing material 6 interposed between these blocks 3 and 4 presents two disadvantages: When the alloy is present across the entire plane beneath the tube 1, an edge effect occurs at the boundary, acting like thermal resistance and limiting heat removal. Furthermore, the presence of the brazing material 6 between blocks 3 and 4 introduces a manufacturing risk of clogging certain tubes 1, prompting a limit on the number of tubes 1 to reduce this risk.

[0020] In both of these brazing cases, the circuits must be constructed within a closed region of the material, particularly by drilling a single element or by milling the outer surface of a coaxial inner element inserted into a coaxial outer element that encloses the tube. Therefore, due to the limitations of machining, it is not possible to produce tubes 1 with complex shapes such as curves. Additive manufacturing techniques can solve the problem of curved outlines, but in the prior art, materials deposited using additive manufacturing techniques cannot withstand certain stresses of thermal expansion when the element in question is heated, relative to the desired design tolerances imposed on the dimensions. Otherwise, they may exhibit large thermal expansion or fail to meet roughness and conductivity requirements. Therefore, this additive manufacturing technique cannot be used under high-temperature conditions.

[0021] In any case, the structure 4 surrounding the small tube 1 exerts a mechanical stress against the thermal expansion of the internal block, generating a mechanical stress.

[0022] The minimum distance between the small tube and the wall directly heated can limit the mechanical stability of the element to be cooled. To reduce the thermal resistance, the cooling flow needs to circulate as close as possible to the heated wall. In that case, the minimum thickness of the material between the small tube and the wall to be cooled cannot provide the required rigidity, and undesirable deformations may occur. As the small tube gradually approaches the wall to be cooled, the size of the material block decreases, resulting in a lack of mechanical rigidity and stability in the overall system. A minimum distance tM to ensure mechanical stability needs to be interposed between the heated wall and the wall to be cooled. Therefore, it is impossible to achieve a thickness limited by the vacuum air density tv, and the heat conduction decreases.

[0023] The small tube extends along the entire length of the cylindrical object to be cooled and causes inhomogeneity in the axial temperature profile in the case of a heat load showing very prominent spikes in the axial distribution. This generates mechanical stress in the structure as a result of the steep axial temperature gradient.

[0024] The straight outer shape of the small tube creates a certain distance between the fluid flow and the heated surface. When there is a non-uniform heat load along the small tube, it is impossible to minimize the temperature spikes on the heated surface.

[0025] [Figure 4] shows the prior art of the small tube 1 formed by the groove 7 on the outer surface of the wall 8 of the internal cavity 9 and the sleeve 10.

[0026] [Figure 5] and [Figure 6] also show other views of the embodiment of [Figure 4].

[0027] In all cases, the structure 10 connected to both ends of the element 9 to be cooled exerts a mechanical stress against the thermal expansion of the internal element 9 in the axial direction, generating a mechanical stress.

[0028] In all cases, a single heat transfer fluid inlet located at a specific position accelerates the heat transfer fluid in the vicinity of the inlet itself. The velocity of the heat transfer fluid decreases as it moves away from the inlet. As a result, heat exchange away from the heat transfer fluid inlet decreases, and the temperature of the element to be cooled is azimuthally non-uniform.

[0029] An object of the present invention is to mitigate the above problems.

Means for Solving the Problems

[0030] The proposed invention aims to improve the cooling of applicable elements and the thermo-mechanical robustness. For example, this solution can be applied to cavities, collectors, and any element to be cooled.

[0031] Elements to be cooled of any geometric layout can benefit from the proposed invention, and cylindrical, square, or conical geometries, as well as frustum geometries, can form objects to which a cooling circuit with routed small tubes can be applied.

[0032] This solution can be equally applied to particle accelerators in both electron tubes or solid states and passive elements. A device to which the present invention is particularly applicable is a gyrotron.

[0033] One aspect of the present invention is an electronic system, comprising - an external jacket, - the wall of an internal cavity to be cooled, - at least one fixed connection that fixes the outer wall of the internal cavity to be cooled to the external jacket, - A heat transport fluid cooling circuit comprising a groove on the outer surface of the wall of the internal cavity, a flexible portion coplanar with the outer surface of the outer wall of the internal cavity and thereby forming a small tube with the groove, and a sleeve having a non-zero longitudinal component, wherein the flexible portion has a first end portion with a first thickness greater than the second thickness of a continuous second portion of the flexible portion, the second portion is continuous with a third portion of the sleeve having a third thickness greater than the first and second thicknesses, and contacts a jacket located outside the outer jacket, - At least one circumferential extension of the wall of the internal cavity that creates a connection point intended to hold the sleeve in place, - The space between the outer wall of the inner cavity and the sleeve in the flexible part of the sleeve, We propose an electronic system equipped with the following features.

[0034] According to one embodiment, the first thickness is at least twice the second thickness, and the third thickness is at least twice the second thickness.

[0035] In one embodiment, the system includes at least three connection points that connect the sleeve and the walls of the internal cavity with respect to longitudinal translation.

[0036] According to one embodiment, the connection point includes brazing, welding, and / or heat shrink connection.

[0037] In one embodiment, the system includes an expandable bellows on the external jacket.

[0038] According to one embodiment, the system is provided with at least one inlet for a cooling circuit into the space between the outer jacket and the sleeve at the opening of the outer jacket, so as to maximize the path of the heat transport fluid from the inlet to the small tube and introduce homogeneity into the axial velocity of the fluid in the space.

[0039] In one embodiment, the tube is straight or curved.

[0040] According to one embodiment, the small tube has a circular, semicircular, or rectangular cross-section.

[0041] In one embodiment, the system comprises a heat transport fluid distributor having a jacket located outside the outer jacket, thereby forming a heat transport fluid chamber located above several inlets to the opening of the outer jacket into the space between the outer jacket and the sleeve.

[0042] According to one embodiment, the inlet of the heat transport fluid distributor is arranged in a circular shape on the outer jacket.

[0043] In one embodiment, the entrance is rectangular, circular, square, and / or semicircular.

[0044] According to one embodiment, the grooves forming the small tubes contain a porous medium.

[0045] According to one embodiment, the outer jacket includes a layer of a ceramic or metallic porous material (e.g., tungsten or rhenium foam or ultramet®).

[0046] In one embodiment, the walls of the internal cavity comprise copper, particularly Glidcop®, mixed with ceramic alumina particles.

[0047] According to one embodiment, the system is a resonant cavity, an electron vacuum tube, or a gyrotron.

[0048] The present invention is described in general by non-limiting examples and will be better understood by studying some embodiments shown in the accompanying drawings. [Brief explanation of the drawing]

[0049] [Figure 1] This diagram schematically illustrates an electronic system cooled by small tubes, as in conventional technology. [Figure 2] This diagram schematically illustrates an electronic system cooled by small tubes, as in conventional technology. [Figure 3] This diagram schematically illustrates an electronic system cooled by small tubes, as in conventional technology. [Figure 4] A schematic diagram shows an electronic system having small tubes formed by grooves on the outer surface of the walls of the internal cavity and sleeve, according to prior art. [Figure 5] Another schematic diagram of the system shown in [Figure 4] using conventional technology is provided below. [Figure 6] Another schematic diagram of the system shown in [Figure 4] using conventional technology is provided below. [Figure 7] A schematic diagram shows an electronic system having small tubes formed by grooves on the outer surface of the walls of an internal cavity and a sleeve, according to one aspect of the present invention. [Figure 8] Another schematic diagram of the system shown in [Figure 7] according to one aspect of the present invention is shown. [Figure 9] Another schematic diagram of the system shown in [Figure 7] according to one aspect of the present invention is shown. [Figure 10] An example of the path of a small tube in a cross-section according to one aspect of the present invention is schematically shown. [Figure 11] A schematic example of a cross-section of a small tube according to one aspect of the present invention is shown. [Figure 12] The existence of a heat transport fluid distributor according to one aspect of the present invention is schematically shown. [Figure 13] A schematic diagram of the details of a small tube according to one aspect of the present invention is shown. [Figure 14] A schematic cross-section of a small tube according to one aspect of the present invention is shown. [Figure 15] A schematic example of a heat transport fluid distributor according to one aspect of the present invention is shown. [Figure 16] A schematic cross-sectional view of a distributor according to one aspect of the present invention is shown in [Figure 15]. [Figure 17] Figure 15 schematically shows the internal structure of a distributor according to one aspect of the present invention. [Figure 18] The evolution of a thermal load spike according to one aspect of the present invention is schematically shown. [Figure 19] The longitudinal effect of thermal load according to one aspect of the present invention is schematically shown. [Figure 20] The transverse effect of thermal load according to one aspect of the present invention is schematically shown. [Figure 21] The transverse effect of thermal load according to one aspect of the present invention is schematically shown. [Figure 22] The presence of a porous medium in a small tube according to one aspect of the present invention is schematically shown. [Figure 23] This diagram schematically illustrates the difference between embodiments of the present invention in which a porous medium is present in a small tube and in which it is not. [Figure 24] A schematic representation of one embodiment of the system according to one aspect of the present invention is shown. [Figure 25] A schematic representation of one embodiment of the system according to one aspect of the present invention is shown. [Modes for carrying out the invention]

[0050] Elements with the same reference number are identical throughout the figure.

[0051] As shown in Figures 7, 8, and 9, the proposed electronic system is -External jacket 11, -The wall 12 of the internal cavity 13 to be cooled, - At least one fixing connection 5 for fixing the outer wall 12 of the internal cavity 13 to be cooled to the outer jacket 11, - A heat transport fluid cooling circuit 14 comprising a groove 15 on the outer surface 16 of the outer wall 12 of the inner cavity 13, a flexible portion 18 located coplanar with the outer surface 16 of the outer wall 12 of the inner cavity 13, thereby forming a small tube 19 with the groove 15, and a sleeve 17 having non-zero longitudinal components, wherein the flexible portion 18 has a first end portion 18a having a first thickness greater than the second thickness of a continuous second portion of the flexible portion 18, and the second portion 18b is continuous with a third portion 17c of the sleeve 17 having a third thickness greater than the first and second thicknesses, and contacts a jacket 23 located outside the outer jacket 11, - At least one circumferential extension of the wall 12 of the internal cavity 13, which creates a connection point intended to hold the sleeve 17 in place, - The space 20 between the outer wall 12 of the inner cavity 13 and the sleeve 17 in the flexible portion 18 of the sleeve 17, It is equipped with.

[0052] The sleeve is a cylindrical component that is press-fitted.

[0053] Preferably, the first thickness is at least twice the second thickness, and the third thickness is at least twice the second thickness.

[0054] The electronic system comprises at least three connection points or one continuous connection connecting the sleeve 17 and the wall 12 of the internal cavity 13 with respect to longitudinal translation. The connection points 20a or continuous connection may include brazing, welding, and / or heat shrink connections. For example, circumferential extensions may be produced using pins, for example, four pins 20a, or using a continuous circumferential extension including an opening.

[0055] The electronic system may include an expandable bellows 21 on the outer jacket 11. The heat transport fluid may include water, air, or oil.

[0056] The cooling circuit having the small tube 19, when circular, typically has a diameter of 0.2 mm to 2 mm, or a cross-sectional area of ​​π / 100 mm². 2 ~πmm 2 It includes a network of small tubes 19 through which a heat transport fluid used to cool the internal cavity 13 circulates. The distance between the heat transport fluid flow and the wall of the internal cavity can be minimized to the minimum distance that guarantees the vacuum density tv.

[0057] The short length of the tube 19 is due to its inlet, which must be positioned to correspond to the heat load spike. This allows for a very high-speed inlet to the tube 19, and as a result, the heat transport coefficient is higher than that of the rest of the tube, which corresponds precisely to the rest of the heat transport fluid path in the zone where the peak is required (the zone where the maximum heat load exists). As a result of this design, the temperature profile becomes flat or constant along the axial coordinate because the jet of cold fluid is directed towards the maximum heat load. Consequently, better cooling allows for lower thermal expansion of the material, resulting in lower expansion forces that the material imparts to the sleeve 17, and therefore lower mechanical stress on the sleeve 17. Another advantage of the short tube is the significant reduction in pressure drop distributed over the length of the tube, and therefore the overall total pressure drop in the circuit is reduced, and in particular the pressure drop is halved compared to conventional technology (2-3 bar instead of 5-6 bar at a fluid flow rate of approximately 45-55 l / min).

[0058] These tubes are formed between two different elements: probably made of two different materials: an internal cavity 13 with a low coefficient of thermal expansion (typically made of copper mixed with ceramic alumina particles) of 16 μm / mK to 17 μm / mK and a sleeve 17 with a high thermal conductivity (typically made of copper) of 17.5 μm / mK to 18 μm / mK.

[0059] The coaxial external element or sleeve 17 is implemented in the form of an empty, flexible external structure with thermal expansion of the coaxial internal element or internal cavity 13, thereby reducing the mechanical stress that may be induced in the structure.

[0060] Typically, for a portion of the wall 12 of an internal cavity 13 having a groove 15 with a thickness of 0.1 mm to 1 mm, the thickness of the second portion 18b of the flexible portion 18 is typically 0.3 mm to 3 mm, as shown in Figure 8.

[0061] Due to the ratio of the thicknesses between the first portion 18a, the second portion 18b, and portion 17c at the end, the wall 12 of the internal cavity 13 can expand with stress equivalent to thermal stress, rather than with large mechanical stress, thanks in particular to the flexible portion 18 which allows the sleeve 17 to expand with increasing diameter under the effect of thermal expansion of the wall 12 of the internal cavity 13. Thus, the level of mechanical stress at the boundary between the wall 12 and the flexible portion 18 is less than or equal to the thermal stress that would have been applied to the outer surface of the wall 12 if the flexible portion 18 were not present or if a Raschig ring were present in that location.

[0062] Furthermore, the particularly flexible portion 18 of the sleeve 17 can expand as its diameter increases under the effect of the water flow rate through the small tube 19. The particularly flexible portion 18 of the sleeve 17 can also contract as its diameter decreases under the effect of the water flow.

[0063] The term "flexibility" is used herein to characterize the ability of a sleeve to exhibit these two properties described above.

[0064] The heat transport fluid distributor 22 comprises a heat transport fluid injection section 26 and a jacket 23 located outside the outer jacket 11, forming a heat transport fluid chamber 24 located above several inlets 25 to the opening of the outer jacket 11 into the space between the outer jacket 11 and the sleeve 17.

[0065] Sleeve 17 also acts as a fluid distributor, further homogenizing the velocity of the heat-transporting fluid.

[0066] The tube 19 may have at least one curve. Such a curve brings the tube 19 closer to the heated wall 12 and, where applicable, eliminates the brazing joint when spots of brazing material are present at both ends of the cavity. The curved tube 19 reaches (deeper) into the material of the wall 12 of the internal cavity 13, allowing the heat transport fluid flow to come into direct contact with the portion of the wall 12 closest to the most heated internal cavity 13. This makes it possible to improve heat conduction only in zones characterized by heat load spikes, resulting in a more homogeneous axial temperature profile, thereby avoiding mechanical stress.

[0067] The path of the tube 19 in a plane that transcends the direction of the heat-transporting fluid (i.e., substantially transcends the axis of the cavity if the cavity is cylindrical) can be straight, inclined, or bent, as shown in [Figure 10].

[0068] The cross-section of the small tube 19 can have any geometric shape without limitation, such as circular, semicircular, square, or rectangular, and [Figure 11] shows some examples. A shape including an arch is preferred for releasing force.

[0069] The cooling circuit 14 having the small tubes 19 can be implemented using the walls 12 of the internal cavity 13 of any geometric configuration (cylindrical, square, conical, etc.) to be cooled.

[0070] The expandable flexible bellows 21 allow the wall 12 to be cooled to expand while eliminating any stress that might be added by other connected elements.

[0071] The cooling circuit 14 is a dynamic system that evolves over time: the cross-section and position of the small tubes 19 change during the heating process, thanks to the axial and circumferential lengthening of the heated system, until a stable state is reached. The dynamic movement of the system is temperature-controlled.

[0072] Figure 12 shows, in particular, one embodiment of the heat transport fluid distributor 22 in which the expandable bellows 21 are not included.

[0073] The present invention enables the creation of a cooling circuit 14 that has low thermal resistance between the surface of the wall 12 to be cooled and the heat transport fluid, while simultaneously ensuring mechanical stability and material integrity, limiting deformation induced by thermal expansion, and at the same time maintaining control over mechanical and thermal stresses (using brazing, welding, or heat shrink joint connections of various elements).

[0074] The present invention improves thermal management through the optimized cross-section and optimized position of the small tube 19.

[0075] Heat conduction is maximized by minimizing the distance between the heat-transporting fluid and the heated inner wall 12, while simultaneously providing a safety margin in the vacuum density. This distance can be minimized to a thickness limited by the vacuum density tv.

[0076] Heat conduction is improved, allowing for a significant reduction in temperature and corresponding limitation of thermal stress.

[0077] The heat transport fluid flow is in direct contact with the element being cooled (wall 12) without any intervening elements or any brazing / welding alloys.

[0078] The cross-section of the pipe can be curved in the direction of the heat-transporting fluid flow, thereby getting as close as possible in the depth direction to the heated wall 12 to be cooled.

[0079] In the case of a gyrotron cavity, cooling can be performed using a minimum thickness of 0.1 mm to 1 mm under the tubes, with 50 to 200 tubes, and the cross-section of the tubes consists of two zones: a semicircular cross-section zone with a diameter generally in the range of 0.1 mm to 1 mm and a rectangular cross-section zone with a side length generally in the range of 0.1 mm to 1 mm.

[0080] For example, in the case of a gyrotron cavity operating at 100 GHz to 200 GHz, cooling can be performed using a minimum thickness of 0.8 mm to 1 mm below the tubes, with 50 to 90 tubes in total. The cross-section of each tube consists of two zones: a semicircular cross-section zone with a diameter of approximately 1 mm and a rectangular cross-section zone with sides of approximately 0.5 mm to 0.7 mm. The circumferential spacing between tubes is similar to the circumferential width of the tubes.

[0081] This invention improves the management of thermal expansion and stress.

[0082] Such a system limits thermal expansion by an external jacket 11 that applies a moderate amount of mechanical stress (compared to conventional small-tube circuits) to the walls 12 of the coaxial internal cavity 13.

[0083] The inlet to the small tube 19, where maximum convective heat conduction is observed, is positioned as close as possible to the heat load spike. This minimizes temperature spikes on the heated surface, resulting in a "flatter" temperature profile and a reduction in thermal stress.

[0084] The possibility of the material not expanding makes it possible to avoid generating high mechanical stress. The stress level is maintained at the same level as the actual cavity of the Raschig ring, while significantly improving heat conduction.

[0085] As the coaxial external elements expand under the influence of heat, as shown in [Figure 13], they are generated in the form of a hollow, flexible structure called a sleeve 17, which applies moderate mechanical stress to the coaxial internal elements, i.e., the walls 12 of the internal cavity 13.

[0086] The cross-section of the tube 19 may include arched elements to utilize the typical force release principle of an arch. As shown in [Figure 14], thicker walls alternating with the tube 19 provide mechanical stability.

[0087] The present invention improves thermal homogenization and limits detectable anisotropic deformation by homogenizing a two-stage heat transport fluid distributor 22. An exemplary embodiment of the distributor 22 is shown in detail in Figures 15, 16, and 17.

[0088] The heat transport fluid supply is arranged around the outer jacket 11, with narrow inlets 25 or holes located near the heat transport fluid injection point 26, larger holes located further away from the heat transport fluid injection point, and other intermediate-sized holes located on the side opposite the injection point (where the two components of the circumferential velocity that separate near the injection point rejoin). The distributor 22 acts like a collection of multiple inlets 25 where the velocity of the heat transport fluid is constant at different positions and different distances from the fluid injection point 26. As a result, the axial velocity of the heat transport fluid is constant in the azimuthal direction.

[0089] A secondary distribution chamber 24 is created by the sleeve 17, which ultimately homogenizes the velocity of the heat-transporting fluid in the direction entering the small tube 19, as shown in [Figure 9]. Once the heat-transporting fluid reaches the wall of the sleeve 17 with a homogeneous circumferential velocity effect, the heat-transporting fluid is deflected toward the inlet of the small tube 19.

[0090] The inlet of the small tube 19 is positioned near the heat load spike to take advantage of the high thermal conductivity coefficient generated by the high-speed heat-transporting fluid. Before reaching equilibrium, the position of the heat load spike shifts to the right along the axial coordinate as a result of thermal deformation of the inner surface, as shown in Figures 18 and 19. The proposed invention addresses this problem by creating a cooling circuit as a dynamic system whose geometry changes as it evolves over time and is heated and cooled, and heat conduction (as well as the velocity and pressure drop of the heat-transporting fluid) is temperature-controlled.

[0091] The axial position of the coaxial jacket of the heat transport fluid distributor 22 is controlled by the temperature of the cavity 13 (via its axial thermal expansion): it follows the position of pressure spikes as the transient heating conditions evolve until it reaches a stable position.

[0092] For this reason, the axial movement corresponding to the axial thermal expansion of the coaxial internal element (cavity 13) is applied to the coaxial external element (jacket of the heat transport fluid distributor 22).

[0093] A coaxial external element (the jacket of the heat transport fluid distributor 22) is connected to the free section of the cavity 13. Under stable conditions, the heat load spike moves toward a specific location (towards an upward cone in the gyrotron). The present invention allows the jet of heat transport fluid to be directed as close as possible to the heat load spike while the cavity 13 is being heated. The thermal expansion of the cavity 13 is used to move the sleeve 17: the position of the heat transport fluid inlet into the tube 19 is controlled by the thermal expansion of the cavity 13: as the cavity 13 expands, the sleeve 17 moves, causing the inlet of the tube 19 to follow the evolution of the position of the heat load spike.

[0094] As shown in Figures 20 and 21, the cross-section of the tube 19 is temperature-controlled: a space is left between the outer wall 12 (groove) of the cavity 13 and the inner wall of the sleeve 17, which is kept cold. Therefore, when heating begins, a bypass exists, and the size of the bypass gradually decreases until a steady state is reached, at which point the cross-section of the tube 19 reaches its nominal shape. At the start of transient heating of the cavity 13, a bypass exists between the cavity and the sleeve 17, and consequently the opening of the tube. As the cavity 13 expands circumferentially, the tube 19 is activated. In the steady state, the tube 19 reaches its final cross-section.

[0095] A third level of fluid distribution, similar to the first level, can be located at the outlets around the shaft: a narrow hole near the fluid extraction point and a larger hole further away. This structure generates a set of multiple outlets. The effect is to increase the azimuthal homogeneity of the pressure distribution at the outlets. As demonstrated by numerical calculations based on the geometry of a ThalesTH1507U gyrotron, this leads to a better azimuthal distribution of fluid velocity in the pipe, and therefore to a more homogeneous azimuthal distribution of temperature.

[0096] As one variation, it is possible to utilize the advantages of the principle of a porous medium heat exchanger, as shown in [Figure 22] and [Figure 23].

[0097] To improve heat exchange, the tube 19 may include the presence of a porous medium placed inside the tube 19. The effects of this configuration are primarily an increase in the surface area available for heat exchange, a reduction in the laminar sublayer near the walls, and improved fluid mixing. When the tube 19 is machined, a foam material that forms the medium can be deposited inside the tube 19. After solidification, the coaxial internal elements can be re-machined to conform to the external shape.

[0098] The presence of a porous medium in the tube 19 allows the number of tubes 19 to be increased compared to a solution where the tubes 19 are empty, and the spacing between the tubes can be reduced to 1 / 10 of the circumferential spacing between the tubes. This is possible because the presence of the porous medium introduces a certain degree of mechanical robustness.

[0099] Compared to conventional porous media heat exchangers, this solution offers improved mechanical stability, incorporates a two-stage fluid distributor, and utilizes dynamic changes in temperature control over time due to the geometry.

[0100] As shown in Figures 24 and 25, the present invention can be achieved by copper electroforming, or by 3D additive manufacturing of a second element on a first element, by milling and then joining two elements together by brazing, welding, or heat shrink bonding.

[0101] The machining process is relatively simple and follows conventional manufacturing procedures.

[0102] [Figure 24] is a simplified diagram of a manufacturing method using milling / brazing, in which the coaxial internal element is machined to drill holes in the rear surface of the tube, and the coaxial external element is inserted as shown in [Figure 25] and then brazed, welded, or joined away from the small tube.

[0103] It is also possible to use a method involving copper electroforming: the outer shape of the small tube 19 on the coaxial internal element is drilled using conventional machining procedures, the outer shape of the tip of the small tube 19 shared with the external material is produced by lost-wax deposition, an appropriate amount of wax is applied to obtain a negative shape of the tube and fitted using conventional drilling procedures, the coaxial external element is manufactured by copper electroforming, the wax is removed by a thermal process, and finally the outer shape of the coaxial external element is adjusted to fit using conventional drilling methods.

[0104] If the material produced by additive manufacturing meets the requirements for thermal conductivity, surface roughness, elastic limit, and fracture stress required for the application under consideration, the same method can be achieved by additive manufacturing of external elements (the most commonly considered application being a gyrotron).

[0105] This solution can be applied to all electron tubes and electronic devices, as well as devices containing semiconductors or passive elements that need to be cooled.

[0106] Elements to be cooled in any geometric arrangement may benefit from the proposed invention: geometries such as cylindrical, square, or conical, and frustoconical shapes may be subject to the application of cooling circuits including small tubes.

[0107] Cooling the cavity of a gyrotron is one particularly advantageous application of the proposed invention. [Explanation of Symbols]

[0108] 5 Fixed connection 11. Outer jacket 12 walls 13 Internal Cavity 14 Heat transport fluid cooling circuit 15 groove 16 Exterior 17 sleeves 17c Third part 18 Flexible part 18a Part 1 18b Part 2 19 Canaliculus 20 space 20a Connection point 21 Expandable bellows 22 Heat transport fluid distributor 23 Jacket 24 Heat-transporting fluid chamber 25 Entrance 26 Injection points

Claims

1. An electronic system, comprising: - an outer jacket (11); - a wall (12) of an internal cavity (13) to be cooled; - at least one fixed connection for fixing the outer wall (12) of the internal cavity (13) to be cooled to the outer jacket (11); - a groove (15) on an outer surface (16) of the wall (12) of the internal cavity (13), and a flexible portion (18) located in the same plane as the outer surface (16) of the outer wall (12) of the internal cavity (13), thereby forming a small tube (19) with the groove (15), and a sleeve (17) having a non-zero longitudinal component, wherein the flexible portion (18) comprises a first end portion (18a) having a first thickness greater than a second thickness of a continuous second portion of the flexible portion (18), and the second portion (18b) is continuous with a third portion (17c) of the sleeve (17) having a third thickness greater than the first and second thicknesses, and is in contact with a jacket (23) located outside the outer jacket (11), a heat transfer fluid cooling circuit (14); - at least one circumferential extension of the wall (12) of the internal cavity (13) configured to create a connection point (20a) for holding the sleeve (17) in place; - a space (20) between the outer wall (12) of the internal cavity (13) and the sleeve (17) in the flexible portion (18) of the sleeve (17); An electronic system comprising the above.

2. The electronic system according to claim 1, wherein the first thickness is at least twice the second thickness, and the third thickness is at least twice the second thickness.

3. The electronic system according to claim 1 or 2, comprising at least three connection points (20a) connecting the sleeve (17) and the wall (12) of the internal cavity (13) with respect to longitudinal translation.

4. The electronic system according to claim 3, wherein the connection point (20a) includes soldering, welding, and / or heat shrink connection.

5. The electronic system according to claim 1 or 2, comprising an expandable bellows (21) on the outer jacket (11).

6. An electronic system according to claim 1 or 2, wherein at least one of the inlets (25) of the cooling circuit (14) into the space between the outer jacket (11) and the sleeve (17) is provided at an opening of the outer jacket such that the path of the heat transfer fluid from the inlet (25) to the small tube (19) is maximized.

7. An electronic system according to claim 1 or 2, wherein the small tube (19) is straight or curved.

8. An electronic system according to claim 1 or 2, wherein the small tube (19) has a circular, semi-circular, or rectangular cross-section.

9. With respect to longitudinal translation, at least three connection points (20a) connecting the sleeve (17) and the wall (12) of the internal cavity (13), the connection points (20a) including brazing, welding, and / or heat shrink connection, An electronic system according to claim 1 or 2, comprising a heat transfer fluid distributor (22) having a jacket (23) located outside the outer jacket (11), thereby forming a heat transfer fluid chamber (24) located above several inlets (25) to an opening of the outer jacket (11) into the space between the outer jacket (11) and the sleeve (17).

10. An electronic system according to claim 9, wherein the inlets (25) of the heat transfer fluid distributor (22) are circularly arranged on the outer jacket (11).

11. An electronic system according to claim 10, wherein the inlets (25) are rectangular, circular, square, and / or semi-circular.

12. An electronic system according to claim 1 or 2, wherein the groove (15) forming the small tube (19) includes a porous medium.

13. An electronic system according to claim 1 or 2, wherein the outer jacket (11) includes a layer of a porous material of a ceramic or metal system.

14. An electronic system according to claim 1 or 2, wherein the wall (12) of the internal cavity (13) includes copper mixed with ceramic alumina particles.

15. An electronic system according to claim 1 or 2, wherein the sleeve (17) includes copper or copper mixed with ceramic alumina particles.

16. An electronic system according to claim 1 or 2, which is a resonant cavity, an electron vacuum tube, or a gyrotron.

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