Cooling device

Abstract

The invention provides a cooling device which is used for cooling a heating body in a cooling pond and comprises a heat exchange base body capable of covering the heating body, a cooling structure arranged on the heat exchange base body and a liquid supplementing part arranged on the cooling structure and deviating from one side of the heat exchange base body. A channel is defined by the heat exchange base body, the cooling structure and the liquid supplementing part, the channel is provided with a first end and a second end, and the cross sectional area of the channel is gradually increased from the first end to the second end in the extending direction of the channel; bubbles can be discharged out of the channel from the second end under the guide of the side wall of the channel, and a cooling medium in the cooling pond can be supplemented into the channel through the liquid supplementing part. The situation that a large number of bubbles are gathered to form an air film which covers the surface of a heating body and hinders rewetting of a cooling working medium on the surface of the heating body, and consequently the heat transfer performance is sharply deteriorated is effectively delayed, and the effect of improving the cooling efficiency is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of enhanced heat transfer, and in particular to a cooling device. Background Art

[0002] The rapid development of modern technologies such as high-performance computing, high-frequency communications, and artificial intelligence (AI) is driving increasing demands for chip integration and miniaturization. This has led to a continuous increase in chip power density, posing significant thermal management challenges. High power density can significantly increase temperatures, impacting chip reliability and lifespan. Therefore, efficient heat dissipation technology is crucial to ensuring safe and stable chip operation.

[0003] Among related technologies, research hotspots in cooling heat-generating elements such as electronic chips include indirect cold plates and immersion cooling. Immersion cooling is further divided into single-phase cooling and phase change cooling. Compared with single-phase cooling, phase change cooling offers better heat transfer efficiency and unique advantages in maintaining temperature uniformity. However, under high heat flux conditions, bubbles tend to converge and form an air film that covers the surface of the heat-generating element. This hinders the rewetting of the heat-generating element by the cooling medium, resulting in a sharp deterioration in heat transfer performance. Summary of the Invention

[0004] In view of this, the present invention aims to provide a cooling device to help improve cooling efficiency.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A cooling device for cooling a heating element in a cooling pool, the cooling device comprising:

[0007] A heat exchange substrate capable of covering the heating element, a cooling structure provided on the heat exchange substrate, and a liquid replenishing portion provided on the cooling structure and facing away from the heat exchange substrate;

[0008] The heat exchange matrix, the cooling structure and the liquid replenishing portion form a channel, the channel having a first end and a second end, and a cross-sectional area of ​​the channel gradually increases from the first end to the second end along the extending direction of the channel;

[0009] Under the guidance of the side wall of the channel, the bubbles can be discharged from the second end to the outside of the channel, and the cooling medium in the cooling pool can be replenished into the channel through the liquid replenishing part.

[0010] Furthermore, the cooling structure includes a plurality of guide plates arranged along a preset direction, and two adjacent guide plates, the heat exchange matrix and the liquid replenishing portion form the channel.

[0011] Furthermore, the cooling structure also includes: a base column arranged on the heat exchange base; the preset direction is the circumference of the base column, and multiple guide plates are distributed along the circumference of the base column; one end of the guide plate is connected to the base column, and the other end of the guide plate extends along the radial direction of the base column toward the edge of the heat exchange base.

[0012] Furthermore, the angle between two adjacent guide plates ranges from 5° to 30°, and / or the angles between two adjacent guide plates are distributed at equal angles.

[0013] Furthermore, the preset direction is the length or width direction of the heat exchange base; the guide plate is in the shape of a long strip, and in the length direction of the guide plate, the cross-sectional area of ​​the guide plate gradually decreases from the center of the guide plate to the two ends of the guide plate; the first end is located at the center of the length direction of the guide plate, and the second end is located at the two ends of the length direction of the guide plate.

[0014] Furthermore, the preset direction is the length or width direction of the heat exchange substrate, and the two adjacent guide plates form a group. One end of the two guide plates in the same group are close to each other to form the first end, and the remaining end is away from each other to form the second end; the first end and the second end of the two adjacent channels are alternately arranged along the preset direction.

[0015] Furthermore, the cooling structure is coated with a temperature-sensitive wettability coating; the components of the temperature-sensitive wettability coating include 1H,1H,2H,2H-perfluorodecyltrichlorosilane and TiO2.

[0016] Furthermore, the surface of the heat exchange substrate is hydrophilic.

[0017] Furthermore, the surface of the heat exchange base provided with the cooling structure is rectangular or circular; the base column is located at the center of the heat exchange base, and the end of the guide plate away from the base column extends to the edge of the heat exchange base.

[0018] Furthermore, the fluid replenishing part includes a fluid replenishing plate arranged on the cooling structure, and the fluid replenishing plate is made of one or more of foam metal, expanded polytetrafluoroethylene, polyimide aerogel and porous polyetheretherketone, and / or,

[0019] The cooling structure (2) is made of one of copper, silicon, aluminum, polytetrafluoroethylene, polyimide, polyetheretherketone, zirconium tungstate, invar alloy, scandium fluoride, nickel titanium alloy, and copper-zinc-aluminum alloy.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The cooling device described in the present invention, by setting up a channel, as bubbles are formed and grow in the channel, under the restriction and guidance of the channel side walls, the bubbles present a shape with a small head and a large tail, that is, the bubbles gradually expand from the side close to the first end to the side close to the second end. The bubbles of the above shape will move in the expansion direction under the action of surface tension, thereby promoting the bubbles to escape from the channel from the second end under the guidance of the channel side walls.

[0022] At the same time, the more bubbles generated in the channel, the more steam there is. The more steam there is, the greater the channel resistance. Since flow resistance is proportional to pressure drop, the channel pressure with more bubbles is lower. In the rehydration section, the coolant flow rate is low and the pressure gradient is relatively small. The coolant is transported to the channel with higher resistance and lower pressure, thus replenishing the coolant in the channel. This delays the accumulation of bubbles to form an air film covering the surface of the heating element, which hinders the rewetting of the cooling medium on the surface of the heating element, thereby causing a sharp deterioration in heat transfer performance and improving cooling efficiency.

[0023] Moreover, under the same inlet pressure, the pressure of the channel with more bubbles is lower, and the fluid replenishment of the channel is relatively more timely, thereby achieving targeted cooling medium replenishment for different channels corresponding to different positions of the heat exchange matrix, and more uniform cooling of the heat exchange matrix.

[0024] Secondly, by setting the angle between the two adjacent guide plates to a range of 5°-30°, it is convenient for the bubbles to form a small head and a large tail as they continue to grow in the channel, that is, it is convenient for the bubbles to be in an expanded state in the channel. At the same time, it effectively avoids the situation where the bubbles tend to be long strips due to the angle between the two adjacent guide plates being too small, and the expansion state presented in the channel is not obvious, making it impossible for the bubbles to be discharged out of the channel along the expansion direction under the action of surface tension. It also effectively avoids the situation where the bubbles cannot be restricted and guided due to the angle between the two adjacent guide plates being too large, so that there is no squeezing force from the channel on both sides of the bubbles, causing the bubbles to tend to be spherical, and the expansion state presented in the channel is not obvious, making it impossible for the bubbles to be discharged out of the channel along the expansion direction under the action of surface tension.

[0025] In addition, by setting a temperature-sensitive wettability coating, and because the bubble's demand for wettability changes dynamically at different moments from bubble formation to detachment, the hydrophobic cooling structure is more conducive to nucleation and can effectively reduce the nucleation superheat, while the hydrophilic surface can reduce the bubble base radius, accelerate the contraction of the three-phase line, and facilitate the detachment of the bubble. In terms of macroscopic performance, the hydrophobic surface has a smaller initial nucleation temperature (ONB), so its boiling heat transfer coefficient (HTC) is higher than that of the hydrophilic surface in the early stage, but the bubbles are easier to detach on the hydrophilic surface, and the liquid is replenished more quickly, so the boiling heat transfer coefficient of the hydrophilic surface in the later stage is higher, and it has a higher critical heat flux density (CHF). In summary, setting a temperature-sensitive wettability coating is conducive to the generation and detachment of bubbles, which helps to further improve the cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

[0028] Figure 2 Schematic diagram of the arrangement of the heat exchange matrix, cooling structure and liquid replenishing part according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic structural diagram of a cooling structure according to an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of coating a temperature-sensitive wettability coating on a cooling structure according to an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the arrangement of the heat exchange matrix, cooling structure and liquid replenishing part according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic structural diagram of a cooling structure according to an embodiment of the present invention;

[0033] Figure 7 Schematic diagram of the arrangement of the heat exchange matrix, cooling structure and liquid replenishing part according to an embodiment of the present invention;

[0034] Figure 8 This is a schematic structural diagram of the cooling structure according to an embodiment of the present invention.

[0035] Description of reference numerals:

[0036] 1. Heat exchange substrate; 2. Cooling structure; 201. Guide plate; 202. Base column; 3. Fluid replenishing part; 31. Fluid replenishing plate; 4. Channel; 4a. First end; 4b. Second end; 5. Temperature-sensitive wettability coating; 6. Cooling pool; 7. Heating element; 8. Bubble; α. Angle; β. Preset direction; γ. Expansion direction. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0038] In the description of the present invention, it should be noted that if terms such as "upper," "lower," "inner," and "outer" appear to indicate orientation or positional relationships, these are based on the orientation or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, if terms such as "first" and "second" appear, they are used solely for descriptive purposes and should not be construed as indicating or implying relative importance.

[0039] Furthermore, in the description of the present invention, unless otherwise expressly defined, the terms "mounted," "connected," "connect," and "connector" should be interpreted broadly. For example, they may refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will appreciate the specific meanings of these terms in the present invention based on the specific circumstances.

[0040] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0041] This embodiment relates to a cooling device that realizes self-driving of boiling bubbles and directional fluid replenishment through a spatial structure, thereby helping to improve cooling efficiency.

[0042] Existing research hotspots in cooling technologies for heating elements 7, such as electronic chips, include indirect cold plates and immersion cooling. Immersion cooling is further divided into single-phase cooling and phase change cooling. Compared with single-phase cooling, phase change cooling offers better heat transfer efficiency and unique advantages in maintaining temperature uniformity. However, under high heat flux conditions, bubbles 8 generated during phase change cooling tend to converge and form an air film that covers the surface of the heating element 7. This hinders the rewetting of the surface of the heating element 7 by the cooling medium, resulting in a sharp deterioration in heat transfer performance.

[0043] Example 1

[0044] In terms of overall structure, Figures 1 to 3As shown, the cooling device is used to cool the heating element 7 in the cooling pool 6. The cooling device includes a heat exchange substrate 1 that can be wrapped around the heating element 7, a cooling structure 2 provided on the heat exchange substrate 1, and a fluid replenishing portion 3 provided on the cooling structure 2 and facing away from the heat exchange substrate 1. The heat exchange substrate 1, the cooling structure 2, and the fluid replenishing portion 3 form a channel 4. The channel 4 has a first end 4a and a second end 4b. Along the extension direction of the channel 4, the cross-sectional area of ​​the channel 4 gradually increases from the first end 4a to the second end 4b. Under the guidance of the side wall of the channel 4, the bubbles 8 can be discharged from the second end 4b to the outside of the channel 4, and the cooling medium in the cooling pool 6 can be replenished into the channel 4 through the fluid replenishing portion 3.

[0045] Through the above arrangement, as the bubble 8 is formed and grows in the channel 4, under the restriction and guidance of the side wall of the channel 4, the bubble 8 presents a shape with a small head and a large tail, that is, the bubble 8 gradually expands from the side close to the first end 4a to the side close to the second end 4b. The bubble 8 of the above shape will move in the expansion direction γ under the action of surface tension, thereby promoting the bubble 8 to detach from the channel 4 from the second end 4b under the guidance of the side wall of the channel 4.

[0046] At the same time, in the channel 4, the more bubbles 8 are generated, the more steam there is. The more steam there is, the greater the resistance of the channel 4. Since the flow resistance is proportional to the pressure drop, the more bubbles 8 are generated, the lower the pressure of the channel 4. In the rehydration section 3, the cooling medium flow rate is low and the pressure gradient is relatively small. The cooling medium is transported to the channel 4 with higher resistance, that is, lower pressure, to achieve rehydration of the cooling medium in the channel 4. This delays the aggregation of a large number of bubbles 8 to form an air film covering the surface of the heating element 7, hindering the re-wetting of the surface of the heating element 7 by the cooling medium, thereby causing a sharp deterioration in the heat transfer performance and improving the cooling efficiency. At the same time, under the same inlet pressure, the pressure of the channel 4 with more bubbles 8 generated is lower, and the rehydration of the channel 4 is relatively more timely, thereby achieving targeted cooling medium replenishment for different channels 4 corresponding to different positions of the heat exchange substrate 1, and more uniform cooling of the heat exchange substrate 1. It is understandable that when the amount of bubbles 8 generated is small, that is, the heat flux density is small, the channel 4 can also promote the discharge of the bubbles 8, and at the same time, the liquid replenishing part 3 can also replenish liquid into the channel 4.

[0047] Based on the above overall introduction, it is worth mentioning that Figure 1As shown, in this embodiment, the cooling pool 6 is filled with a coolant, and the heating element 7 and the cooling device are immersed in the coolant. Under pool boiling conditions, phase change cooling technology primarily relies on the formation, growth, rapid detachment, and timely rehydration of bubbles 8. Heat generated by the heating element 7 is transferred from the heat exchange matrix 1 to the cooling structure 2. When the temperature reaches the saturation temperature of the coolant and reaches a certain degree of superheat, the vaporization core of the coolant in the channel 4 is activated first because the temperature reaches the activation temperature first, generating bubbles 8 that gradually grow. The volume of the bubbles 8 increases, generating an expansion force. Under the action of the sidewalls of the channel 4, a counteracting squeezing force is applied, accelerating the expansion of the originally expanding bubbles 8 toward the second end b. Specifically, the curvature of the same bubble 8 at the first end a is smaller than the curvature at the second end b. Therefore, the surface tension of the bubble 8 at the first end a is smaller, and this difference in force drives the bubble 8 toward the second end b. Common cooling media can be selected, such as water, fluorinated liquid, methanol, ethanol, acetone, etc. Fluorinated liquid is preferably used as the cooling medium in this embodiment.

[0048] Based on the above introduction, in detail, Figure 3 As shown, the cooling structure 2 includes multiple guide plates 201 arranged along a predetermined direction β. Two adjacent guide plates 201, the heat exchange substrate 1, and the liquid replenishing portion 3 enclose a channel 4. In specific implementation, in this embodiment, the cooling structure 2 also includes a base column 202 disposed on the heat exchange substrate 1. The predetermined direction β is the circumferential direction of the base column 202, and the multiple guide plates 201 are distributed circumferentially along the base column 202. One end of the guide plate 201 is connected to the base column 202, and the other end of the guide plate 201 extends radially from the base column 202 toward the edge of the heat exchange substrate 1.

[0049] By setting as above, the guide plate 201 is centered on the base column 202 and distributed along the circumference of the base column 202, which makes it easy for the bubbles 8 to separate from the channel 4 along the circumference of the heat exchange matrix 1, so as to achieve heat dissipation around the heat exchange matrix 1, which helps to further make the cooling of the heat exchange matrix 1 more uniform.

[0050] As a preferred embodiment of the cooling structure 2 as described above, preferably, the surface of the heat exchange substrate 1 provided with the cooling structure 2 is rectangular or circular; the base column 202 is located at the center of the heat exchange substrate 1. This arrangement helps to make the lengths of the two channels 4 symmetrical about the center of the base column 202 consistent, thereby helping to make the growth and detachment time of the bubbles 8 consistent. As another preferred embodiment of the cooling structure 2, one end of the preferred guide plate 201 is fixedly connected to the base column 202, and the remaining end extends to the edge of the heat exchange substrate 1, and the liquid replenishing portion 3 can be completely covered on the contact surface of the guide plate 201. Such an arrangement helps to increase the area of ​​the channel 4 and the area of ​​liquid replenishment in the channel 4, which helps to dissipate heat from the heat exchange substrate 1 as a whole.

[0051] Meanwhile, as a preferred embodiment of the cooling structure 2, specifically, during implementation, the angle α between two adjacent guide plates 201 ranges from 5° to 30°. The adjacent guide plates 201 are evenly distributed. For example, the angle α can be 5°, 10°, 15°, 20°, 25°, or 27°, with the preferred angle α being 15°.

[0052] The above arrangement facilitates the formation of a small head and a large tail of bubble 8 within channel 4 as it continues to grow, that is, facilitates the expansion of bubble 8 within channel 4. At the same time, it effectively avoids the situation where the angle α between two adjacent guide plates 201 is too small, causing bubble 8 to tend to be elongated, with a less obvious expansion state within channel 4, thus preventing bubble 8 from being discharged out of channel 4 along the expansion direction γ under the action of surface tension. It also effectively avoids the situation where the angle α between two adjacent guide plates 201 is too large, preventing the bubble 8 from being restricted and guided, resulting in the bubble 8 being free of squeezing pressure from channel 4 on both sides, causing bubble 8 to tend to be spherical, with a less obvious expansion state within channel 4, thus preventing bubble 8 from being discharged out of channel 4 along the expansion direction γ under the action of surface tension.

[0053] When the angle α between two adjacent guide plates 201 is equal, it helps to make the two adjacent channels 4 tend to be the same size, that is, it helps to make the corresponding heat exchange substrates 1 tend to be the same area, so that the cooling of the heat exchange substrate 1 is more uniform.

[0054] Based on the above overall introduction, Figure 4 As shown, the cooling structure 2 is coated with a temperature-sensitive wettability coating 5; the components of the temperature-sensitive wettability coating 5 include 1H,1H,2H,2H-perfluorodecyltrichlorosilane and TiO2.

[0055] Through the above arrangement, and because the wettability requirements of the bubble 8 change dynamically at different moments from the formation to the detachment of the bubble 8, the hydrophobic cooling structure 2 is more conducive to nucleation and can effectively reduce the nucleation superheat, while the hydrophilic surface can reduce the base radius of the bubble 8, accelerate the contraction of the three-phase line, and facilitate the detachment of the bubble 8. In terms of macroscopic performance, the hydrophobic surface has a smaller initial nucleation temperature (ONB), so its boiling heat transfer coefficient (HTC) is higher than that of the hydrophilic surface in the early stage. It is impossible to restrict and guide the bubble 8, so that there is no squeezing pressure from the channel 4 on both sides of the bubble 8, causing the bubble 8 to tend to a spherical surface, but the bubble 8 is easier to detach on the hydrophilic surface, and the liquid is replenished more quickly. Therefore, the boiling heat transfer coefficient of the hydrophilic surface in the later stage is higher, and it has a higher critical heat flux density (CHF). In summary, the provision of a temperature-sensitive wettability coating 5 facilitates the generation and detachment of the bubble 8, and helps to further improve the cooling efficiency.

[0056] As an optional embodiment of the temperature-sensitive wettability coating 5, in detail, as an optional embodiment of producing and applying the temperature-sensitive wettability coating 5, for example, 0.2 grams of TiO2 is added to 100 milliliters of anhydrous ethanol, ultrasonically dispersed for 30 minutes, and then 1 milliliter of 1H,1H,2H,2H-perfluorodecyltrichlorosilane is added. Magnetic stirring is continued for 30 minutes to prepare a spray of the temperature-sensitive wettability coating 5. The spray is sprayed onto the cooling structure 2 using a spray gun and then dried at 60°C for 1 hour, thereby forming the temperature-sensitive wettability coating 5 with temperature-responsive dynamic wettability.

[0057] As a preferred embodiment, in this embodiment, the surface of the heat exchange substrate 1 is hydrophilic, which allows bubbles 8 to escape from the heat exchange substrate 1 more easily, allowing the coolant to flow more smoothly within the channel 4, thereby improving cooling efficiency. For example, the heat exchange substrate 1 can be made of copper, aluminum nitride, silicon carbide, aluminum, graphite, etc., as long as the heat exchange substrate 1 meets the thermal conductivity and hydrophilicity requirements.

[0058] As described above, the cooling structure 2 is made of one of copper, silicon, aluminum, polytetrafluoroethylene, polyimide, polyetheretherketone, zirconium tungstate, invar, scandium fluoride, nickel titanium alloy, and copper-zinc-aluminum alloy. Specifically, when manufacturing the cooling structure 2, one of the above materials, such as copper, can be selected to manufacture the cooling structure 2. Preferably, more than one of the above materials, such as copper and aluminum, can also be selected to manufacture the cooling structure 2 in layers along the axial direction of the base column 202.

[0059] With the above configuration, when water is used as the coolant, copper with high thermal conductivity can be used for indirect heat transfer. Using aluminum to manufacture the cooling structure 2 helps reduce production costs. Since the chip is made of silicon, using silicon to manufacture the cooling structure 2 helps reduce contact thermal resistance. Polytetrafluoroethylene, polyimide, and polyetheretherketone (PEEK) have lower thermal conductivity when used to manufacture the cooling structure 2. In this case, the cooling structure 2 primarily serves to guide the bubbles 8. It is worth noting that when one of zirconium tungstate, Invar, and scandium fluoride is used to manufacture the cooling structure 2, since these materials are all negative thermal expansion materials, as the coolant temperature increases, the cross-section of the guide plate 201 gradually decreases, thereby gradually increasing the cross-sectional area of ​​the channel 4. Conversely, as the coolant temperature decreases, the cross-sectional area of ​​the channel 4 gradually decreases. When the coolant temperature is low, the cross-sectional area of ​​the channel 4 is smaller. Furthermore, bubbles 8 are generally fewer at low coolant temperatures, and bubbles 8 occasionally aggregate and grow larger. In this case, the smaller cross-sectional area of ​​the channel 4 helps to squeeze the bubbles 8. When the temperature of the cooling medium is high, the channel 4 becomes larger and the amount of bubbles 8 increases. The increase in the cross-sectional area of ​​the channel 4 is conducive to the discharge of the bubbles 8 from the channel 4, thereby further improving the cooling efficiency.

[0060] When cooling structure 2 is made of either nickel-titanium alloy or copper-zinc-aluminum alloy, since these alloys are memory metals, the coolant temperature is relatively low, and the cross-sectional area of ​​channel 4 is relatively small when cooling structure 2 is in the martensite state. When the coolant temperature rises, causing cooling structure 2 to be in the austenite state, the cross-sectional area of ​​channel 4 increases. When the coolant temperature is relatively low, bubbles 8 are generally rare, occasionally agglomerating and growing larger. However, when the coolant temperature is relatively high, channel 4 enlarges and the number of bubbles 8 increases. Therefore, using nickel-titanium alloy or copper-zinc-aluminum alloy for cooling structure 2 facilitates the discharge of bubbles 8 from channel 4.

[0061] Based on the above, as an exemplary preparation description of a negative thermal expansion material, zirconium tungstate, also known as ZrW2O8, is produced by first accurately weighing high-purity ZrO2 and WO3 in a 1:2 molar ratio and mixing and grinding them evenly in a ball mill. The mixed powder is then placed in a crucible and pre-fired at 900°C for 12 hours to form a precursor, which is then sintered at 1100°C for 24 hours to generate a single-phase ZrWO8 crystal. Preferably, hot isostatic pressing treatment can be performed to increase the density, and the material obtained by this method has stable isotropic negative thermal expansion properties.

[0062] As an exemplary preparation description of a memory alloy, in order to achieve a smaller channel 4 area when the cooling medium is around 60°C in the nickel-titanium alloy, and to restore the channel 4 area to a larger state when the cooling medium is above 70°C, first, a nickel-titanium alloy with a titanium content of approximately 50.8–51.0at.% is selected, prepared by vacuum melting, and then solution treated at 850°C and quenched in water to ensure that the phase transition temperature Af is above 70°C. Subsequently, the material is manually deformed into a state with a smaller cross-sectional area of ​​channel 4 in a cold state (below Af), and then heated to a temperature above Af to restore it to a state with a larger cross-sectional area of ​​channel 4. Thermal-mechanical cycle training is repeated to form a stable two-way shape memory effect. To this end, the nickel-titanium alloy is in a martensite state at 60°C and the cross-sectional area of ​​channel 4 is smaller. Only when the temperature is above Af does the austenite phase transformation occur to increase the cross-sectional area of ​​channel 4.

[0063] As described above, the rehydration section 3 includes a rehydration plate 31 disposed on the cooling structure. The rehydration plate 31 is made of one or more of the following materials: metal foam, expanded polytetrafluoroethylene, polyimide aerogel, and porous polyetheretherketone. It is understood that the rehydration section 3 can be made of one of the aforementioned materials, or two or more materials, such as a composite rehydration section 3 formed of two or more layers of metal foam and expanded polytetrafluoroethylene along the thickness of the rehydration plate 31. This allows the rehydration section 3 to have a porous structure, thereby allowing the cold zone working fluid to pass through the rehydration section 3.

[0064] It is worth noting that the foam metal can be foam copper, foam aluminum, foam zinc or other foam metals, so that the liquid replenishing part 3 can have a porous structure, thereby allowing the cold zone working medium to pass through the liquid replenishing part 3.

[0065] In the cooling device described in the embodiment of the present application, as bubbles 8 form and grow within the channel 4, they are restricted and guided by the sidewalls of the channel 4, and the bubbles 8 exhibit a shape with a small head and a large tail. That is, the bubbles 8 gradually expand from the side near the first end 4a to the side near the second end 4b. The bubbles 8 of this shape will move in the expansion direction γ under the action of surface tension, thereby promoting the bubbles 8 to escape from the channel 4 from the second end 4b under the guidance of the sidewalls of the channel 4. At the same time, the more bubbles 8 are generated within the channel 4, the more steam there is. The greater the steam, the greater the resistance of the channel 4. Since the flow resistance is proportional to the pressure drop, the pressure in the channel 4 with more bubbles 8 is lower. In the rehydration section 3, the cooling medium flow rate is low and the pressure gradient is relatively small. The cooling medium is transported to the channel 4 with higher resistance, i.e., lower pressure, to replenish the cooling medium within the channel 4. This delays the formation of an air film by the bubbles 8, which hinders the rewetting of the surface of the heating element 7 by the cooling medium, thereby causing a sharp deterioration in heat transfer performance and improving cooling efficiency.

[0066] Example 2

[0067] The difference between this embodiment and the first embodiment is that, in this embodiment, Figure 5 and Figure 6 As shown, preferably, the surface of the heat exchange substrate 1 provided with the cooling structure 2 is rectangular. In a specific implementation, the preset direction β is the length or width direction of the heat exchange substrate 1; the guide plate 201 is long and strip-shaped, and in the length direction of the guide plate 201, the cross-sectional area of ​​the guide plate 201 gradually decreases from the center of the guide plate 201 to the two ends of the guide plate 201; the first end 4a is located at the center of the guide plate 201 in the length direction, and the second end 4b is located at the two ends of the guide plate 201 in the length direction.

[0068] This arrangement allows a channel 4 to have a first end 4a and two second ends 4b, meaning that the same channel 4 has two openings capable of discharging bubbles 8. This facilitates the flow of liquid from the liquid replenishing portion 3 into the channel 4, further improving cooling efficiency. Preferably, along the length of the guide plate 201, both ends of the guide plate 201 extend to the edge of the heat exchange substrate 1, with the liquid replenishing portion 3 covering the guide plate 201.

[0069] It is understood that the surface of the heat exchange base 1 on which the cooling structure 2 is disposed may also be circular or have other irregular shapes. If it is circular, the preset direction β may be set to be any radial direction of the heat exchange base 1. If it is an irregular shape, the preset direction β of the heat exchange base 1 only needs to be set to be perpendicular to the guide plate 201.

[0070] It is worth noting that when the surface of the cooling structure 2 is preferably set in a rectangular shape on the heat exchange substrate 1, the side surfaces of the guide plates 201 at both ends of the cooling structure 2 along the preset direction β, which are away from each other, can be set as planes due to the limitation of the surface of the heat exchange substrate 1 on which the cooling structure 2 is set. This setting can reduce the volume of the cooling structure 2 and facilitate the adjacent arrangement of multiple heat exchange substrates 1.

[0071] It is understandable that when the surface of the heat exchange substrate 1 on which the cooling structure 2 is arranged is circular or has other irregular shapes, the side surfaces of the guide plates 201 at both ends of the cooling structure 2 along the preset direction β that face away from each other can conform to the edge of the cooling substrate.

[0072] Example 3

[0073] The difference between this embodiment and the first embodiment is that, in this embodiment, preferably, Figure 7 and Figure 8 As shown, the surface of the heat exchange base 1 on which the cooling structure 2 is provided is rectangular. In a specific implementation, the preset direction β is the length or width direction of the heat exchange base 1, and two adjacent guide plates 201 form a group. One end of the two guide plates 201 in the same group is close to each other to form a first end 4a, and the remaining end is away from each other to form a second end 4b; the first end 4a and the second end 4b of the two adjacent channels 4 are alternately arranged along the preset direction β.

[0074] Through the above arrangement, under the condition that the surface of the heat exchange substrate 1 is constant, the length of the channel 4 is effectively increased, and the amount of bubbles 8 in the channel 4 is effectively increased, so as to further reduce the pressure in the channel 4, thereby facilitating the liquid replenishment part 3 to replenish liquid into the channel 4, and thus helping to further improve the circulation of the cooling medium in the channel 4, and helping to further improve the cooling efficiency.

[0075] It is understood that the surface of the heat exchange base 1 on which the cooling structure 2 is disposed may also be circular or have other irregular shapes. If it is circular, the preset direction β may be set to be any radial direction of the heat exchange base 1. If it is an irregular shape, the preset direction β of the heat exchange base 1 only needs to be set to be perpendicular to the guide plate 201.

[0076] It is worth noting that when the surface of the heat exchange substrate 1 on which the cooling structure 2 is preferably provided is rectangular, the sides of the guide plates 201 at both ends of the cooling structure 2 along the preset direction β that are away from each other can be set to be flat due to the limitation of the surface of the heat exchange substrate 1 on which the cooling structure 2 is provided. This setting can reduce the volume of the cooling structure 2 and facilitate the adjacent arrangement of multiple heat exchange substrates 1.

[0077] It is understandable that when the surface of the heat exchange substrate 1 on which the cooling structure 2 is arranged is circular or has other irregular shapes, the side surfaces of the guide plates 201 at both ends of the cooling structure 2 along the preset direction β that face away from each other can conform to the edge of the cooling substrate.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cooling device for cooling a heating element (7) in a cooling pool (6), characterized in that: The cooling device comprises: A heat exchange substrate (1) capable of being coated on the heating element (7), a cooling structure (2) provided on the heat exchange substrate (1), and a liquid replenishing portion (3) provided on the cooling structure (2) and facing away from the heat exchange substrate (1); The heat exchange base (1), the cooling structure (2) and the liquid replenishing portion (3) form a channel (4), the channel (4) having a first end (4a) and a second end (4b), and along the extending direction of the channel (4), the cross-sectional area of ​​the channel (4) gradually increases from the first end (4a) to the second end (4b); Under the guidance of the side wall of the channel (4), the bubbles (8) can be discharged from the second end (4b) to the outside of the channel (4), and the cooling medium in the cooling pool (6) can be replenished into the channel (4) through the liquid replenishing part (3).

2. The cooling device according to claim 1, characterized in that: The cooling structure (2) comprises a plurality of guide plates (201) arranged along a preset direction (β), and two adjacent guide plates (201), the heat exchange matrix (1) and the liquid replenishing portion (3) form the channel (4).

3. The cooling device according to claim 2, characterized in that: The cooling structure (2) further comprises: a base column (202) provided on the heat exchange base (1); The preset direction (β) is the circumferential direction of the base column (202), and the plurality of guide plates (201) are distributed along the circumferential direction of the base column (202); One end of the guide plate (201) is connected to the base column (202), and the other end of the guide plate (201) extends radially toward the edge of the heat exchange base (1) along the base column (202).

4. The cooling device according to claim 3, characterized in that: The angle (α) between two adjacent guide plates (201) is in the range of 5°-30°, and / or, The two adjacent guide plates (201) are distributed at equal angles.

5. The cooling device according to claim 2, characterized in that: The preset direction (β) is the length or width direction of the heat exchange substrate (1); the guide plate (201) is in the shape of a long strip, and in the length direction of the guide plate (201), the cross-sectional area of ​​the guide plate (201) gradually decreases from the center of the guide plate (201) to the two ends of the guide plate (201); The first end (4a) is located at the center of the guide plate (201) in the length direction, and the second end (4b) is located at both ends of the guide plate (201) in the length direction.

6. The cooling device according to claim 2, characterized in that: The preset direction (β) is the length or width direction of the heat exchange substrate (1), two adjacent guide plates (201) form a group, one end of the two guide plates (201) in the same group are close to each other to form the first end (4a), and the remaining ends are away from each other to form the second end (4b); The first ends (4a) and the second ends (4b) of two adjacent channels (4) are alternately arranged along the preset direction (β).

7. The cooling device according to claim 1, characterized in that: The cooling structure (2) is coated with a temperature-sensitive wettability coating (5); the components of the temperature-sensitive wettability coating (5) include 1H,1H,2H,2H-perfluorodecyltrichlorosilane and TiO2.

8. The cooling device according to claim 1, characterized in that: The surface of the heat exchange substrate (1) is hydrophilic.

9. The cooling device according to claim 3, characterized in that: The surface of the heat exchange base (1) on which the cooling structure (2) is provided is rectangular or circular; The base column (202) is located at the center of the heat exchange base (1), and the end of the guide plate (201) facing away from the base column (202) extends to the edge of the heat exchange base (1).

10. The cooling device according to claim 1, characterized in that: The fluid replenishing portion (3) comprises a fluid replenishing plate (31) arranged on the cooling structure (2), wherein the fluid replenishing plate (31) is made of one or more of foam metal, expanded polytetrafluoroethylene, polyimide aerogel and porous polyetheretherketone, and / or, The cooling structure (2) is made of one of copper, silicon, aluminum, polytetrafluoroethylene, polyimide, polyetheretherketone, zirconium tungstate, invar alloy, scandium fluoride, nickel titanium alloy and copper-zinc-aluminum alloy.

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