Condensation strengthening surface with microcolumn array and application of condensation strengthening surface in phase change heat transfer assembly

Abstract

The invention relates to a condensation strengthening surface with a micro-column array and application of the condensation strengthening surface in a phase change heat transfer assembly, the condensation strengthening surface comprises a substrate layer and a micro-column array structure arranged on the surface of the substrate layer, the micro-column array structure comprises condensation column units and capillary column units, and the condensation column units and the capillary column units are sequentially and alternately distributed at intervals. The condensation column unit is used for promoting nucleation and rapid separation of condensate drops, and the capillary column unit is used for adsorbing and guiding reflux of condensate. Compared with the prior art, the condensation reinforced surface provided by the invention has the advantages of high-density nucleation, rapid liquid discharge, low liquid film thermal resistance and good machinability, and can solve the problems of condensate retention, large liquid film thermal resistance, low interface updating rate, insufficient liquid discharge path, poor long-term stability and the like of the existing condensation surface; and the heat exchanger can be widely applied to phase change heat transfer assemblies such as a vapor chamber, a conventional heat pipe and a gravity assisted heat pipe so as to improve the condensation heat exchange efficiency and the circulation stability.

Description

Technical Field

[0001] This invention relates to the field of phase change heat transfer and enhanced heat transfer technology, and in particular to a condensation-enhancing surface with a micropillar array and its application in phase change heat transfer components. Background Technology

[0002] Phase change heat transfer technology, due to its high thermal conductivity, high heat flux density carrying capacity, and excellent temperature uniformity, is now widely used in thermal management fields such as heat dissipation of electronic devices, vapor chambers, heat pipes, and cold plates. In phase change systems, the condensation heat transfer performance directly determines the overall cycle efficiency and stability. However, on traditional metal planar condensation surfaces, condensate usually adheres in a film form. The liquid film has high thermal resistance and makes droplet discharge difficult, resulting in a significant reduction in the condensation heat transfer coefficient. At the same time, condensate retention can also cause local "liquid accumulation" at the condensation heat transfer points, making it difficult to effectively separate steam and condensate, further inhibiting the interface renewal rate during the condensation process.

[0003] To address the low condensation efficiency of traditional planar condenser surfaces, existing technologies primarily employ surface roughening, hydrophobic coatings, or simple microstructure textures to improve droplet nucleation and detachment behavior. However, these methods still have significant drawbacks: First, surface roughening or sandblasting methods result in uncontrollable structural dimensions and uneven distribution of nucleation points, easily forming liquid films or bridges, which actually increases condensation resistance. Second, hydrophobic coatings rely on chemical coatings, which have poor temperature and corrosion resistance, and are prone to aging and peeling during long-term use, leading to a decline in condensation performance. Third, simple textured structures often lack a clear drainage path design, allowing condensate to remain on the surface under gravity or surface tension, hindering rapid interface renewal. Furthermore, existing structures generally suffer from low processing precision, poor repeatability, or difficulty in achieving stable and consistent microstructures over large areas, failing to meet the practical requirements for efficient and stable condensation enhancement in high heat flux density phase change systems. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing a condensation-enhanced surface with a micropillar array and its application in phase change heat transfer components. This surface can achieve high-density nucleation, rapid droplet detachment, and efficient drainage at the condensation heat exchange site, while also possessing both processability and long-term stability. This solves the technical problems of condensate retention, high liquid film thermal resistance, and slow interface renewal, effectively improving the cycle stability and heat transfer performance of phase change heat transfer components under high heat flux density conditions.

[0005] The objective of this invention can be achieved through the following technical solution: a condensation-enhancing surface with a micropillar array, comprising a substrate layer and a micropillar array structure disposed on the surface of the substrate layer, wherein the micropillar array structure comprises condensation column units and capillary column units that are alternately distributed in sequence, wherein the condensation column units are used to promote the nucleation and rapid detachment of condensate droplets, and the capillary column units are used to adsorb and guide the reflux of condensate.

[0006] Furthermore, the condensation column unit is a solid micro-column structure, and the capillary column unit is a capillary porous structure column with a through-hole micropore network, forming interconnected micropore channels inside.

[0007] The condensation column unit is the main carrier for the nucleation and growth of condensate droplets, while the capillary column unit adsorbs and aggregates the condensate on the adjacent condensation column units and guides the condensate to move towards the reflux area through capillary drive, thereby constructing a continuous and stable reflux path.

[0008] In practical applications, capillary column units are composed of porous materials with capillary liquid absorption capabilities. These porous materials form an interconnected network of micropores, providing a stable capillary interface and enabling rapid introduction and transport of condensate. Porous materials can be prepared through processing methods that enable the construction of continuous microporous structures, such as sintering, bonding molding, particle or fiber stacking, chemical or physical etching, and additive manufacturing. Porous materials include metal powders, metal fibers, metal meshes, metal foams, ceramic powders, ceramic fibers, or composite structures of the above materials to ensure that the capillary column units possess good capillary driving force and thermal stability.

[0009] Furthermore, the surface of the substrate layer has hydrophobic or superhydrophobic properties, and the surface of the condensation column unit is treated with hydrophobic or superhydrophobic properties to increase the nucleation density of condensed droplets and promote the rapid detachment of droplets after formation, thereby reducing liquid film retention and enhancing interface renewal capability.

[0010] Furthermore, the spacing between the adjacent condenser column units and the capillary column units can be adjusted to control the nucleation size and migration path of the condensate droplets, thereby achieving spontaneous drainage of the condensate.

[0011] Once condensate forms droplets on the surface of the condenser column unit, it can spontaneously migrate to adjacent capillary column units under the combined effect of surface tension difference and geometric potential energy difference. There, it is rapidly adsorbed and introduced by the internal microporous network, thus realizing the transport of condensate from the condensation zone to the reflux zone. Through alternating arrangement and spacing control, not only can droplet retention be reduced, but a stable and efficient spontaneous drainage mechanism can also be formed, thereby continuously maintaining the interface renewal and efficient condensation capacity of the condensation surface.

[0012] Furthermore, the height of the capillary column unit is equal to or greater than the height of the condenser column unit.

[0013] When condensate forms droplets on the surface of the capillary column unit, the taller capillary column unit can contact the droplets under the combined action of gravity, capillary pressure difference, and surface tension difference, thereby achieving full absorption of the condensate and rapid introduction into its internal microporous network. By increasing the height of the capillary column unit, condensate retention on the surface of the condensation column can be effectively prevented, ensuring that the condensate can be guided to the return path in a timely manner, further improving the interface renewal rate and overall drainage efficiency.

[0014] Furthermore, the cross-sectional shape of both the condenser column unit and the capillary column unit is rectangular or polygonal with inclined sidewalls, so that the condensate can flow along the sidewall of the condenser column unit and be guided to the adjacent capillary column unit. The polygonal cross-sectional shape includes a parallelogram, a trapezoid, a triangle, or a combination thereof.

[0015] By appropriately selecting the cross-sectional shape, a surface energy gradient favorable to droplet movement can be formed on the sidewalls of the micropillar array structure. This allows the condensate condensed on the sidewalls of the condensation column units to converge along their outer surface under the combined effects of gravity, surface tension, and differences in wettability, and naturally guide it to adjacent capillary column units. When a polygonal cross-sectional shape with inclined sidewalls is selected, the included angle of the sidewalls formed by the polygonal structure can not only regulate the direction of condensate droplet movement but also, by changing the local curvature and surface energy distribution, enable the condensate to achieve a lower resistance migration path within the micropillar array structure, thereby further optimizing the overall drainage performance and enhancing the condensation strengthening effect.

[0016] Furthermore, the condensation-enhanced surface is applied to the condensation heat exchange section of the phase change heat transfer assembly to enhance condensation heat transfer performance and improve phase change cycle stability. The phase change heat transfer assembly includes a vapor chamber, conventional heat pipes, gravity heat pipes, etc. Specifically, the condensation-enhanced surface provides higher nucleation density and faster drainage capacity during steam condensation. By enhancing condensate separation and reflux, liquid film retention can be effectively reduced, ultimately improving the stability of the phase change cycle and overall heat transfer performance.

[0017] Furthermore, when the condensation-enhancing surface is applied to the condensation end of the vapor chamber, one or more liquid-guiding columns communicating with the evaporation end are provided below the capillary column unit to form a capillary reflux path connecting the evaporation end and the condensation end, thereby enhancing the circulation and temperature uniformity of the working fluid within the vapor chamber. The liquid-guiding column is an integral capillary porous structure column, or a solid column with a capillary structure layer covering its outer surface, or a solid column with liquid-guiding microgrooves processed on its outer surface, used to provide stable capillary liquid absorption capacity and promote the reflux of the working fluid towards the evaporation end along the direction of the liquid-guiding column.

[0018] The cross-sectional shape of the liquid guiding column can be designed according to flow requirements and capillary suction performance. Its cross-section can be any of the following: cylindrical, concave, or convex, or it can be composed of a combination of two or more cross-sectional shapes. Different cross-sectional structures can respectively achieve the effects of enhanced capillary force, accelerated liquid convergence, or reduced reflux resistance, thereby further optimizing the reflux efficiency of the working fluid inside the temperature distribution plate and the overall circulation stability.

[0019] Furthermore, when the condensation-enhancing surface is applied to a conventional heat pipe, the condensation-enhancing surface is a ring structure and is disposed on the surface of the condensation zone inside the conventional heat pipe to improve the nucleation and drainage capacity of the condensation zone. The conventional heat pipe has a wick on its inner wall to connect the condensation zone and the evaporation zone, forming a continuous capillary reflux path. The wick can be a sintered powder wick, a wire mesh wick, a grooved wick, or a combination thereof. It is used to achieve the reflux circulation of the working fluid under the action of capillary force, that is, to drive the working fluid to flow back to the evaporation zone along the pipe wall under the action of capillary force, thereby maintaining the stable operation of the circulation of the working fluid and the phase change heat transfer process inside the conventional heat pipe.

[0020] Furthermore, when the condensation-enhancing surface is applied to a gravity heat pipe, the condensation-enhancing surface is set on the corresponding inner wall surface of the condensation cavity according to the arrangement position of the cold source, so as to enhance the condensation drainage process under gravity. That is, a micro-column array structure is introduced on the inner wall surface corresponding to the cold source to effectively reduce the retention of condensate in the condensation cavity, thereby increasing the renewal frequency of the condensation interface and enhancing the condensation heat exchange capacity. The bottom of the condensation chamber is connected to the evaporation chamber through a pipeline to realize the reflux circulation of the working fluid under the dominance of gravity. That is, the condensate flows back to the evaporation chamber naturally along the pipeline under the action of gravity, thus forming a working fluid reflux circulation mainly driven by gravity.

[0021] The resulting evaporation-condensation cycle maintains stable phase change heat transfer inside the gravity heat pipe and improves overall heat transfer efficiency.

[0022] Furthermore, in practical applications, to improve the overall heat transfer performance of gravity heat pipes during the condensation stage, the outer surface of the condensation cavity can be treated with thermal conductivity or heat dissipation enhancement processes depending on the application scenario. For example, a high thermal conductivity coating, metal plating, or micro / nano roughening structure can be applied to the outer surface of the condensation cavity to reduce the thermal resistance of the outer wall and enhance its heat transfer capacity with the external cold source. Fins, heat dissipation ribs, or microstructure arrays can also be arranged on the outer surface to increase the effective heat transfer area and improve the disturbance effect of external airflow or liquid flow, thereby further improving the overall heat dissipation efficiency of the condensation cavity. Through the above-mentioned external surface treatments, the internal condensation enhancement structure and the external heat dissipation structure can work synergistically to more effectively promote the phase change and reflux process of the working fluid.

[0023] Compared with the prior art, the present invention has the following advantages: This invention employs a micropillar array structure on the surface of a substrate layer. This micropillar array structure comprises alternating condensation column units and capillary column units. The condensation column units promote the nucleation and rapid detachment of condensate droplets, while the capillary column units adsorb and guide the reflux of the condensate. This constructs a micropillar array structure composed of condensation column units and capillary column units, achieving a continuous and synergistic process of condensate "nucleation-migration-absorption-reflux". The condensation column units provide a high-density solid interface for droplet nucleation and growth, while the capillary column units provide strong capillary adsorption capacity through a network of interconnected micropores. This allows the condensate to rapidly migrate from the condensation column units to the interior of the capillary column units under the influence of surface tension difference, geometric potential difference, and capillary force. The condensation-enhanced surface based on this micropillar array structure effectively avoids the problems of liquid film retention and liquid bridge formation on traditional condensation surfaces, significantly improving the interface renewal rate and enhancing condensation heat transfer capacity.

[0024] This invention designs an alternating distribution of condensation column units and capillary column units with adjustable spacing, which can correspondingly control the nucleation size and migration path of condensate droplets on the condensation-enhanced surface, realizing a clear condensate drainage path and directional liquid guidance mechanism. This not only reduces droplet retention but also forms a stable and efficient spontaneous drainage mechanism, thereby continuously maintaining the interface renewal and efficient condensation capacity of the condensation-enhanced surface.

[0025] The present invention designs the height of the capillary column unit to be equal to or greater than the height of the condenser column unit, which effectively prevents the condensate from accumulating on the surface of the condenser column unit and ensures that the capillary column unit preferentially contacts the droplets on the surface of the condenser column unit, thereby improving the liquid absorption efficiency.

[0026] In this invention, the cross-sectional shape of both the condensation column unit and the capillary column unit can be designed as a rectangle or a polygonal structure with inclined sidewalls. This can create a surface energy gradient on the sidewalls of the microcolumn array structure that is conducive to droplet movement. Under the combined action of gravity, surface tension, and wettability differences, the condensate condensed on the sidewalls of the condensation column unit converges along its outer surface and is naturally guided to the adjacent capillary column unit. The included angle of the sidewalls formed by the polygonal structure can not only control the direction of movement of the condensate droplets, but also change the local curvature and surface energy distribution, so that the condensate can achieve a lower resistance migration path in the microcolumn array structure, thereby optimizing the overall drainage performance and improving the condensation enhancement effect.

[0027] The condensation-enhancing surface proposed in this invention is adaptable to various phase change heat transfer components, including vapor chambers, conventional heat pipes, and gravity heat pipes. When applied to vapor chambers, a liquid-guiding column is designed at the bottom of the capillary column unit to form a capillary reflux network connecting the evaporation and condensation ends, making the working fluid circulation more stable. When applied to conventional heat pipes or gravity heat pipes, it can significantly enhance the drainage capacity of the condensation zone or condensation chamber, achieving efficient reflux in conjunction with a wick or gravity drive. The structural design of this invention has good fabrication feasibility, with flexible selection of porous materials and microstructure processing methods, suitable for large-scale preparation, and can provide long-term, stable, and reliable condensation-enhancing effects under high heat flux density conditions. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the condensation-strengthened surface structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the cross-sectional shape of the condenser column unit and the capillary column unit in Embodiment 1 of the present invention; Figure 3 This is a schematic cross-sectional view of the condensation-enhanced surface applied to the heat spreader in Embodiment 2 of the present invention. Figure 4 This is a bottom view of the condenser end in Embodiment 2 of the present invention; Figure 5 This is a schematic cross-sectional view of the condensation-enhancing surface applied to a conventional heat pipe in Embodiment 3 of the present invention. Figure 6 This is a schematic diagram of the cross-sectional structure of the condensation zone in Embodiment 3 of the present invention; Figure 7 This is a schematic diagram of the cross-sectional structure of the evaporation zone in Embodiment 3 of the present invention; Figure 8 This is a schematic diagram of the connection structure of the gravity heat pipe in Embodiment 4 of the present invention; Figure 9 This is a schematic diagram of the internal structure of the condensation-enhancing surface applied to the condensation cavity of the gravity heat pipe in Embodiment 4 of the present invention; Explanation of markings in the diagram: 1. Base layer; 11. Condensation column unit; 12. Capillary column unit; 2. Temperature distribution plate; 21. Condensation end; 22. Evaporation end; 23. Liquid guiding column; 3. Conventional heat pipe; 31. Condensation zone; 32. Evaporation zone; 33. Suction wick; 4. Gravity heat pipe, 41. Condensation chamber, 42. Evaporation chamber, 43. Piping. Detailed Implementation

[0029] To make the technical solution of the present invention clearer, several embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Those skilled in the art can understand the structural features of the condensation-strengthened surface, the interrelationships between the components, and its application in different phase change heat transfer components based on the accompanying drawings. It should be noted that the accompanying drawings are schematic structures and are only used to illustrate the principles and structure of the present invention; in practical applications, the specific dimensions, shapes, proportions, and arrangements of each component can be adjusted accordingly based on the structural requirements and operating conditions of different products. For ease of description, the same or similar reference numerals in the accompanying drawings are used to denote the same or similar structural components.

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0031] Example 1 like Figure 1 As shown, this embodiment provides a condensation-enhanced surface with a micropillar array. The condensation-enhanced surface includes a substrate layer 1 and a micropillar array structure disposed on the surface of the substrate layer 1. The micropillar array structure is composed of several condensation column units 11 and capillary column units 12. The condensation column units 11 are solid micropillars used to provide a nucleation and growth interface for the condensate. The capillary column units 12 are capillary porous structure columns with a network of interconnected micropores, forming interconnected microporous channels inside to adsorb the condensate and guide it to the reflux region.

[0032] The condensation column unit 11 and the capillary column unit 12 are alternately distributed in the micro-column array structure. By adjusting the spacing between them, the nucleation size, migration path, and convergence behavior of the condensate droplets towards the capillary column unit 12 can be effectively controlled, thereby achieving spontaneous drainage of the condensate. At the same time, the height of the capillary column unit 12 is set to be equal to or greater than the height of the condensation column unit 11 to ensure that the condensate droplets can preferentially contact the capillary column unit 12 and be fully absorbed by it after formation, thereby improving drainage efficiency and reducing droplet retention on the surface of the condensation column unit 11.

[0033] In addition, the surface of the base layer 1 may also have hydrophobic or superhydrophobic properties, and the surface of the condensation column unit 11 may also be treated with hydrophobic or superhydrophobic properties, which can further increase the nucleation density of droplets and promote the rapid detachment of the condensate from the surface of the condensation column unit 11 after formation, thereby reducing liquid film retention and maintaining the efficient heat exchange state of condensation.

[0034] like Figure 2As shown, both the condenser column unit 11 and the capillary column unit 12 can have rectangular cross-sectional shapes, or they can adopt a polygonal structure with inclined sidewalls. By providing inclined surfaces on the sidewalls of the condenser column unit 11 and the capillary column unit 12, a surface tension difference can be generated during the formation and movement of the condensate. This allows the condensate to be oriented along the sidewall of the condenser column unit 11 to the adjacent capillary column unit 12, thereby guiding the condensate to migrate into the interior of the capillary structure. The polygonal cross-section can be a parallelogram, trapezoid, triangle, or a combination of the above shapes. The specific shape can be selected according to the direction of liquid flow and the processing method.

[0035] Supported by the aforementioned basic structure, the condensation-enhancing surface of this invention can be applied to different types of phase change heat transfer components. In specific applications, this condensation-enhancing surface is disposed at the condensation heat exchange portion of the phase change heat transfer component to improve the renewal rate of the condensation interface, drainage efficiency, and overall condensation heat exchange capacity, thereby enhancing the stability and heat transfer performance of the phase change cycle. Based on the internal structural characteristics of different phase change heat transfer components, this invention provides the following several typical application embodiments (see Embodiments 2 to 4 for details).

[0036] Example 2 like Figure 3 and Figure 4 As shown, in this embodiment, the condensation-enhancing surface from Example 1 is applied to the condensation end 21 of the temperature distribution plate 2 to enhance the steam condensation process inside the temperature distribution plate 2 and improve the overall temperature uniformity. To ensure that the condensate is absorbed promptly at the condensation end 21 and flows smoothly back to the evaporation end 22, one or more liquid guiding columns 23 are provided below the capillary column unit 12 in this embodiment. The liquid guiding columns 23 are connected to the evaporation end 22 inside the temperature distribution plate 2, and can form a continuous reflux path connecting the evaporation end 22 and the condensation end 21 under capillary force, thereby significantly enhancing the circulation capacity of the working fluid inside the temperature distribution plate and improving the temperature uniformity between the evaporation end and the condensation end.

[0037] In practical applications, the liquid guiding column 23 can be a monolithic capillary porous structure column, a solid column with a capillary structure layer on the outer surface, or a solid column with liquid guiding microgrooves machined on the outer surface. All of these structural forms of the liquid guiding column 23 can provide a stable capillary liquid absorption interface on or inside the column, allowing the condensate to be quickly adsorbed at the condensation end 21 and transported along the direction of the liquid guiding column to the evaporation end 22. This effectively shortens the reflux path, reduces reflux resistance, and improves the working fluid circulation efficiency.

[0038] In this embodiment, by combining the condensation-enhancing surface with a micro-pillar array structure with the liquid guiding column 23, a synergistic heat transfer mechanism of "condensation enhancement + flow guidance and reflux" can be constructed inside the heat spreader 2, so that the heat spreader 2 can still maintain rapid condensation, efficient reflux and high stability phase change cycle under high heat flux density conditions.

[0039] Example 3 like Figures 5 to 7 As shown, in this embodiment, the condensation-enhancing surface from Example 1 is applied to the condensation zone 31 of a conventional heat pipe 3 to improve the condensation efficiency inside the conventional heat pipe 3 and enhance the working fluid circulation capacity. Since the conventional heat pipe 3 is generally cylindrical, the internal vapor will adhere to the pipe wall in the condensation zone 31 and form condensate. Therefore, in this embodiment, the condensation-enhancing surface is processed into a ring structure, which can be continuously arranged along the inner wall of the heat pipe, thereby enhancing the entire condensation process of the condensation zone 31.

[0040] To ensure the smooth return of condensate from condensation zone 31 to evaporation zone 32, a wick 33 is installed on the inner wall of the conventional heat pipe 3, connecting condensation zone 31 and evaporation zone 32. The wick 33 actively adsorbs condensate using capillary action and drives its return along the pipe wall, making it a key component in forming a closed-loop phase change cycle within the conventional heat pipe 3. Depending on the design requirements and manufacturing process of the conventional heat pipe 3, the wick 33 can be a sintered powder core, a wire mesh core, a grooved core, or a combination of these structures. Its porous structure provides continuous capillary force to achieve rapid return and stable circulation of the working fluid within the conventional heat pipe 3.

[0041] With the synergistic effect of the condensation-enhanced surface and the wick 33 structure, this embodiment can form a heat transfer path of "high-efficiency condensation + capillary reflux" inside the conventional heat pipe 3, so that it can maintain stable and efficient thermal cycling performance under high heat flux density operating conditions.

[0042] Example 4 like Figure 8 and Figure 9 As shown, in this embodiment, the condensation-enhancing surface from Example 1 is applied to the gravity heat pipe 4 to improve its condensate drainage and recirculation process under gravity-dominated conditions. Unlike conventional heat pipes 3, which rely on the wick 33 for recirculation, gravity heat pipes 4 typically utilize their own height difference to form natural recirculation. Therefore, the drainage capacity of the condensation section has a more significant impact on the overall heat transfer performance. In this embodiment, the condensation-enhancing surface is disposed in the region corresponding to the cold source on the inner wall of the condensation chamber 41, allowing the condensate to quickly detach along this inner wall surface after formation and flow and converge towards the bottom of the chamber, thereby reducing liquid film retention and increasing the renewal rate of the condensation interface.

[0043] The bottom of the condenser chamber 41 of the gravity heat pipe 4 is connected to the evaporator chamber 42 below via a pipe 43. After the condensate drains from the inner wall of the condenser chamber 41, it can naturally fall back to the evaporator chamber 42 under the action of gravity along the pipe 43, and participate in the phase change process again, forming a complete evaporation-condensation-drainage-reflux cycle. By arranging condensation-enhancing surfaces in the condenser chamber 41, the drainage capacity of the condensate can be effectively enhanced, preventing liquid from stagnating in the condenser chamber 41, thereby improving the working stability of the gravity heat pipe 4 under vertical, inclined, or slight vibration conditions.

[0044] In this embodiment, the combination of the condensation-enhanced surface and the natural reflux mechanism of the gravity heat pipe 4 can significantly improve the condensation heat exchange efficiency and drainage capacity in the condensation chamber 41, enabling it to maintain high circulation efficiency and continuous and stable phase change heat transfer performance.

[0045] In summary, this solution addresses the common problems in existing phase change heat transfer components, such as severe condensate retention, high liquid film thermal resistance, difficulty in timely droplet detachment, slow vapor-liquid interface renewal, and insufficient long-term structural stability. Considering that existing condensation surfaces generally lack clear drainage paths, condensate tends to form continuous liquid films or liquid bridges after condensation between microstructures, leading to a significant decrease in the condensation heat transfer coefficient. At the same time, traditional hydrophobic coating-based strengthening methods have limited durability and are prone to performance degradation under high temperature, repeated condensation cycles, and long-term working fluid immersion conditions, making it difficult to meet the operational requirements of high heat flux density heat dissipation equipment. Therefore, a condensation enhancement scheme that combines high-density nucleation, rapid liquid drainage, low liquid film thermal resistance, and good processability is proposed. The proposed condensation enhancement surface is equipped with a micro-pillar array structure. The structure of this condensation enhancement surface is controllable, the liquid drainage is unobstructed, and it has long-term stable condensation capability. It can solve the problems of condensate retention, high liquid film thermal resistance, low interface renewal rate, insufficient drainage path, and poor long-term stability of existing condensation surfaces. This condensation enhancement surface can be widely used in phase change heat transfer components such as vapor chambers, conventional heat pipes, and gravity heat pipes, and can effectively improve condensation heat exchange efficiency and cycle stability.

[0046] It should be noted that the above embodiments are only used to further illustrate the technical solution of the present invention, and are not intended to limit the scope of protection of the present invention. Without departing from the core idea of ​​the present invention, those skilled in the art can make various equivalent substitutions, adjustments or modifications to the structural form, dimensional parameters, material selection, microstructure morphology, etc. in the above embodiments according to specific application needs, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. A condensation-strengthened surface with a micropillar array, characterized in that, It includes a substrate layer (1) and a micropillar array structure disposed on the surface of the substrate layer (1). The micropillar array structure includes condensation column units (11) and capillary column units (12) that are alternately distributed in sequence. The condensation column units (11) are used to promote the nucleation and rapid detachment of condensate droplets, and the capillary column units (12) are used to adsorb and guide the reflux of condensate.

2. The condensation-strengthened surface with a micropillar array according to claim 1, characterized in that, The condensation column unit (11) is a solid micro-column structure, and the capillary column unit (12) is a capillary porous structure column with a through-hole micropore network, and interconnected micropore channels are formed inside.

3. A condensation-strengthened surface with a micropillar array according to claim 1, characterized in that, The surface of the base layer (1) has hydrophobic or superhydrophobic properties, and the surface of the condensation column unit (11) is treated with hydrophobic or superhydrophobic properties to increase the nucleation density of condensation droplets and promote the rapid detachment of droplets after formation, thereby reducing liquid film retention and enhancing interface renewal capability.

4. A condensation-strengthened surface with a micropillar array according to claim 1, characterized in that, The spacing between the adjacent condenser column unit (11) and the capillary column unit (12) is adjustable to control the nucleation size and migration path of the condensate droplets, thereby achieving spontaneous drainage of the condensate.

5. A condensation-strengthened surface with a micropillar array according to claim 1, characterized in that, The height of the capillary column unit (12) is equal to or greater than the height of the condenser column unit (11).

6. A condensation-strengthened surface with a micropillar array according to claim 1, characterized in that, The cross-sectional shape of the condenser column unit (11) and the capillary column unit (12) is rectangular or polygonal with inclined sidewalls, so that the condensate can flow along the sidewall of the condenser column unit (11) and be guided to the adjacent capillary column unit (12). The polygonal cross-sectional shape includes a parallelogram, a trapezoid, a triangle, or a combination thereof.

7. The application of a condensation-enhanced surface with a micropillar array in a phase change heat transfer assembly, characterized in that, The condensation-enhancing surface is applied to the condensation heat exchange part of the phase change heat transfer component to enhance the condensation heat exchange performance and improve the stability of the phase change cycle. The phase change heat transfer component includes a heat spreader (2), a conventional heat pipe (3), or a gravity heat pipe (4).

8. The application of a condensation-enhanced surface with a micropillar array as described in claim 7 in a phase change heat transfer assembly, characterized in that, When the condensation-enhancing surface is applied to the condensation end (21) of the temperature distribution plate (2), one or more liquid guiding columns (23) communicating with the evaporation end (22) are provided below the capillary column unit (12) to form a capillary reflux path that runs through the evaporation end (22) and the condensation end (21) to enhance the circulation and temperature equalization of the working fluid in the temperature distribution plate (2). The liquid guiding column (23) is an integral capillary porous structure column, or a solid column with a capillary structure layer on the outer surface, or a solid column with liquid guiding microgrooves on the outer surface, to provide stable capillary liquid absorption capacity and promote the reflux of the working fluid to the evaporation end (22) along the direction of the liquid guiding column (23).

9. The application of a condensation-enhanced surface with a micropillar array as described in claim 7 in a phase change heat transfer assembly, characterized in that, When the condensation-enhancing surface is applied to a conventional heat pipe (3), the condensation-enhancing surface is a ring structure and is set on the surface of the condensation zone (31) inside the conventional heat pipe (3) to improve the nucleation and drainage capacity of the condensation zone (31). The conventional heat pipe (3) has a liquid wick (33) on its inner wall to connect the condensation zone (31) and the evaporation zone (32) to form a continuous capillary reflux path. The liquid wick (33) is a sintered powder wick, a wire mesh wick, a grooved wick or a combination thereof, and is used to realize the reflux circulation of the working fluid under the action of capillary force.

10. The application of a condensation-enhanced surface with a micropillar array as described in claim 7 in a phase change heat transfer assembly, characterized in that, When the condensation-enhancing surface is applied to the gravity heat pipe (4), the condensation-enhancing surface is set on the corresponding inner wall surface of the condensation chamber (41) according to the arrangement position of the cold source, so as to enhance the condensation and drainage process under gravity. The bottom of the condensation chamber (41) is connected to the evaporation chamber (42) through a pipe (43) to realize the reflux circulation of the working fluid under the dominance of gravity.

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