Vapor chamber based on biomass aerogel capillary core

Abstract

The invention belongs to the technical field of thin-plate-shaped radiators, and particularly relates to a vapor chamber based on a biomass aerogel capillary core. Comprising an evaporation end shell plate, a biomass aerogel capillary core and a condensation end shell plate which are sequentially arranged from bottom to top in the vertical direction, the biomass aerogel capillary core is located in a closed cavity formed by the evaporation end shell plate and the condensation end shell plate, and the biomass aerogel capillary core makes contact with the evaporation end shell plate and the condensation end shell plate; the biomass aerogel capillary core is a chitosan-cellulose aerogel capillary core, and the porosity of the chitosan-cellulose aerogel capillary core is larger than 95%. The chitosan-cellulose composite aerogel capillary core is designed to replace a traditional capillary core, and the biomass capillary core vapor chamber which is high in capillary driving force, high in liquid backflow capacity, low in cost, novel in manufacturing process, light, environmentally friendly and sustainable is developed.

Description

Technical Field

[0001] The invention belongs to the technical field of thin plate radiators, and in particular relates to a heat spreader based on a biomass aerogel capillary core. Background Art

[0002] As an efficient and lightweight thermal management device, the vapor chamber is widely used in the heat dissipation system of power electronic devices, such as CPU, GPU, LED lighting and high-power laser. One of the core principles of the high heat dissipation effect of the vapor chamber is to use the internal capillary structure to achieve rapid reflux of the liquid working fluid to promote the uniform distribution and phase change efficiency of the liquid working fluid. Therefore, a reasonable capillary core design can significantly improve the thermal conductivity and stability of the vapor chamber, which is the guarantee of the heat dissipation capacity of the vapor chamber. The popular capillary structures of the vapor chamber at this stage include sintered structure core, mesh structure core, microgroove structure core and a composite core composed of the three listed above.

[0003] Although the heat spreader is superior to traditional heat sink fins in terms of heat dissipation performance, space utilization and reliability due to its efficient phase change heat dissipation and uniform heat distribution, and is particularly suitable for thermal management of high-end electronic devices, the traditional heat spreader uses a metal capillary wick, which has a low porosity and fixed aperture design, resulting in low capillary driving force and reflow capacity, and the material manufacturing process of the metal capillary wick is complex and the cost is high. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a heat spreader based on a biomass aerogel capillary core. The present invention designs a chitosan-cellulose composite aerogel capillary core to replace the traditional capillary core, and develops a biomass capillary core heat spreader with high capillary driving force, high liquid reflux capacity, low cost, new manufacturing process, light weight, environmental protection, and sustainable development. The chitosan-cellulose composite aerogel capillary core has high porosity, uniform microporous structure, hydrophilic material properties and multi-scale pores, achieving strong capillary driving force and reflux liquid capacity. These characteristics work together to make the aerogel capillary core perform well in promoting the reflux of condensed liquid and enhancing the efficiency of working fluid circulation, and realize fast and efficient liquid reflux in the aerogel capillary core heat spreader; and the aerogel capillary core is made of two biomass materials, chitosan and cellulose, with a simple manufacturing process, low cost, and the characteristics of light weight, environmental protection and sustainable development.

[0005] The present invention solves the above technical problems through the following technical solutions.

[0006] The object of the present invention is to provide a heat spreader of a biomass aerogel capillary core, comprising an evaporation end shell plate, a biomass aerogel capillary core and a condensation end shell plate arranged in sequence from bottom to top in a vertical direction, wherein the biomass aerogel capillary core is located in a closed cavity formed by the evaporation end shell plate and the condensation end shell plate, and the biomass aerogel capillary core is in contact with the evaporation end shell plate and the condensation end shell plate, and the biomass aerogel capillary core is a chitosan-cellulose aerogel capillary core, and the porosity of the chitosan-cellulose aerogel capillary core is greater than 95%.

[0007] Furthermore, the method for preparing the biomass aerogel capillary wick comprises the following steps: Dissolving chitosan in an acetic acid solution to obtain a chitosan solution; The cellulose solution is added into the chitosan solution, and cross-linking is performed at 55°C to 65°C to obtain an aerogel precursor, and the aerogel precursor is freeze-dried to obtain a biomass aerogel capillary core.

[0008] Furthermore, the volume ratio of the chitosan solution to the cellulose solution is 1:1, the concentration of the chitosan solution is 2wt.% to 2.4wt.%, and the concentration of the cellulose solution is 1wt.% to 1.2wt%; the cross-linking time is 1.5h to 3h, the freeze-drying temperature is -60℃, and the time is 24h to 48h.

[0009] Furthermore, a groove is provided on the upper surface of the biomass aerogel capillary core, and a space formed between the groove and the condensation end shell plate is used for the flow of steam and condensate.

[0010] Furthermore, the ratio of the depth of the groove to the height of the biomass aerogel capillary core is 1:4-5, and the ratio of the length and width of the groove to the length and width of the biomass aerogel capillary core is 1:0.4-4.5.

[0011] Furthermore, the height ratio of the evaporation end shell plate, the biomass aerogel capillary core and the condensation end shell plate is 14:10:3-5, and the length ratio or width ratio is 90-95:90:90-95.

[0012] Furthermore, the evaporation end shell plate is a frame structure, a plurality of support columns are evenly distributed in the frame structure, the spacing between adjacent support columns is 8 mm to 12 mm, and the ratio of the height of all support columns to the height of the evaporation end shell plate is 10:13 to 15.

[0013] Furthermore, the biomass aerogel capillary core is inserted into all the support columns, and the lower wall of the biomass aerogel capillary core contacts the inner wall of the evaporation end shell plate, and the upper ends of all the support columns contact the inner wall of the condensation end shell plate.

[0014] Furthermore, the cross section of the support column is square, circular or diamond-shaped.

[0015] Furthermore, a liquid injection port is provided on one side wall of the evaporation end shell plate.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (3) The heat spreader provided by the present invention comprises an evaporation end shell plate, a biomass aerogel capillary core and a condensation end shell plate which are arranged in sequence from bottom to top in the vertical direction. The biomass aerogel capillary core is located in a closed cavity formed by the evaporation end shell plate and the condensation end shell plate. The biomass aerogel capillary core is in contact with the evaporation end shell plate and the condensation end shell plate. The biomass aerogel capillary core is a chitosan-cellulose aerogel capillary core. By designing a chitosan-cellulose composite aerogel capillary core to replace the traditional capillary core, a high capillary driving force, high liquid reflux capacity and low The biomass capillary core heat spreader is low-cost, new manufacturing process, lightweight, environmentally friendly and sustainable. The biomass aerogel capillary core has a high porosity (>95%), a uniform microporous structure with a high specific surface area, hydrophilic material properties and multi-scale pores. The high porosity makes the interior of the aerogel capillary core full of tiny pores, providing more capillary channels for the working fluid, forming a close contact with the liquid working fluid, achieving a strong capillary driving force and liquid reflux capability, significantly enhancing the wettability and heat transfer efficiency of the liquid on the capillary core surface, which is beneficial to reducing the thermal resistance of the entire heat spreader.

[0017] (4) The biomass aerogel capillary wick used in the present invention is made of natural polymer biomass materials. Both chitosan and cellulose have abundant hydrophilic groups, which can evenly distribute the liquid working fluid and enhance the evaporation efficiency. Traditional capillary wick materials (such as sintered copper) are slightly inferior in terms of working fluid wettability and may have the risk of local drying up.

[0018] (5) The present invention is made of chitosan and cellulose by freeze-drying, with a porosity of more than 95%. The interior is filled with uniformly distributed micropores (average pore size of about 50 μm), which significantly enhances the capillary driving force and can drive the condensed liquid to quickly return to the evaporation area. At the same time, the uniformity of the microporous structure avoids the flow dead zone and liquid reflux resistance caused by the uneven pore size of the traditional metal capillary core, making the working fluid flow more smoothly inside and preventing the occurrence of local drying. During the freeze-drying process, a certain number of macropores (pore size greater than 200 μm) are also formed in the aerogel capillary core, which together with the micropores constitute a multi-scale pore structure: the macropores are responsible for rapid liquid reflux, and the small pores provide high capillary driving force; this multi-scale structure achieves a dynamic balance between the capillary driving force and the reflux speed, and optimizes the circulation path of the working fluid. In addition, the aerogel capillary core can be processed into different shapes and thicknesses through simple processes to meet the diverse design requirements of heat sinks, effectively solving the development needs of various thin heat sinks and even flexible heat sinks. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic cross-sectional view of the three-dimensional structure of the heat spreader of the present invention.

[0020] Figure 2 It is an exploded view of the three-dimensional structure of the heat spreader of the present invention.

[0021] Figure 3 It is a three-dimensional picture of the biomass aerogel capillary core of the present invention.

[0022] Figure 4 It is a front view of the biomass aerogel capillary core of the present invention.

[0023] Figure 5 It is a top view of the biomass aerogel capillary core of the present invention.

[0024] Figure 6 It is a cross-sectional view of the biomass aerogel capillary core of the present invention.

[0025] Figure 7 It is a three-dimensional diagram of the evaporation end shell plate of the present invention.

[0026] Figure 8 It is a front view of the evaporation end shell plate of the present invention.

[0027] Fig. 9 It is a top view of the evaporation end shell plate of the present invention.

[0028] Fig.10 It is a cross-sectional view of the evaporation end shell plate of the present invention.

[0029] Fig.11 It is a three-dimensional diagram of the condensing end shell plate of the present invention.

[0030] Fig.12 It is a front view of the condensing end shell plate of the present invention.

[0031] Fig.13 It is a top view of the condensing end shell plate of the present invention.

[0032] 1. Evaporation end shell plate, 2. Biomass aerogel capillary core, 3. Condensation end shell plate, 4. Groove, 5. Support column, 6. Liquid injection port. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Certain words are used in the present invention to refer to specific components. Those skilled in the art should understand that technicians will use different nouns to refer to the same component. The present invention does not distinguish between components by the difference in nouns, but by the difference in the functions of the components. As mentioned throughout the specification and claims, "including" is an open term and should be understood as "including but not limited to".

[0035] Since the traditional heat spreader uses a metal capillary wick, the low porosity and fixed pore size design of the metal capillary wick result in low capillary driving force and reflux capacity, and the material manufacturing process of the metal capillary wick is complex and the cost is high. Based on the above problems, the present invention provides a heat spreader with a biomass aerogel capillary wick, such as Figure 1-2 As shown, it includes an evaporation end shell plate 1, a biomass aerogel capillary core 2 and a condensation end shell plate 3 which are arranged in sequence from bottom to top in the vertical direction. The biomass aerogel capillary core 2 is located in a closed cavity formed by the evaporation end shell plate 1 and the condensation end shell plate 3. The biomass aerogel capillary core 2 is in contact with the evaporation end shell plate 1 and the condensation end shell plate 3. The biomass aerogel capillary core 2 is a chitosan-cellulose aerogel capillary core, and the porosity of the chitosan-cellulose aerogel capillary core is greater than 95%.

[0036] Among them, the chitosan-cellulose aerogel capillary core is encapsulated in the evaporation end shell plate 1 and the condensation end shell plate 3. The evaporation end shell plate 1 is cast from copper. In this embodiment, the evaporation end shell plate 1 and the condensation end shell plate 3 are both carved from a copper plate with a length, width and height of 110 mm*110 mm*20 mm. A liquid injection port is provided on one side wall of the evaporation end shell plate 1 for injecting working fluid and maintaining a vacuum environment.

[0037] The heat spreader provided by the present invention develops a biomass capillary core heat spreader with high capillary driving force, high liquid reflux capacity, low cost, new manufacturing process, light weight, environmental protection and sustainable development by designing a chitosan-cellulose composite aerogel capillary core to replace the traditional capillary core. The biomass aerogel capillary core has a high porosity (>95%), a uniform microporous structure with a high specific surface area, hydrophilic material properties and multi-scale pores. The high porosity makes the interior of the aerogel capillary core full of tiny pores, providing more capillary channels for the working fluid, forming a close contact with the liquid working fluid, achieving a strong capillary driving force and liquid reflux capacity, significantly enhancing the wettability and heat transfer efficiency of the liquid on the capillary core surface, and facilitating the reduction of the thermal resistance of the entire heat spreader.

[0038] The biomass aerogel capillary wick 2 has a very high specific surface area (up to 200 m 2 / g), providing a larger adhesion and flow interface for the liquid, further improving the capillary flow ability of the liquid. The biomass aerogel capillary core 2 has an ultra-low density (10000 g / m 3 ), which makes the overall mass of the capillary core much lower than that of the traditional metal capillary core, which is conducive to the lightweight of the overall heat spreader.

[0039] The preparation method of the heat spreader includes the following steps: assembling the evaporation end shell plate 1, the biomass aerogel capillary core 2, and the condensation end shell plate 3 into a whole, welding them into a sealed whole using low temperature welding technology, and then injecting the working fluid, and evacuating to 10 -2 pa, and then weld the liquid injection port to seal to obtain the heat spreader.

[0040] When the heat source (such as a chip or a high heat flux density device) contacts the evaporation end shell plate 1 at the bottom of the vapor chamber, the biomass aerogel capillary core 2 is heated by close contact with the evaporation section shell plate 1, thereby transferring heat to the working fluid. The microporous structure with a high specific surface area and the hydrophilic material in the biomass aerogel capillary core 2 enhance the contact between the liquid working fluid and the capillary core surface. After absorbing heat, the working fluid quickly evaporates into gas, converting the heat from the heat source into the latent heat of the working fluid vapor. The temperature in the evaporation area decreases, and the heat diffuses to the condensation area in gaseous form. After the steam reaches the condensation area, it contacts the condensation end shell plate 3, releases heat and condenses into a liquid working fluid. The condensate flows back to the evaporation area through the porous network of the biomass aerogel capillary core 2. The high porosity (>95%) and small pore size (about 50 μm) provide a strong capillary driving force, which can efficiently reflux even in the direction of gravity unfavorable. The multi-scale pore structure optimizes the liquid flow path, the large pores promote rapid flow, and the small pores maintain the capillary driving force. The hydrophilic groups (such as hydroxyl and amino groups) enhance the wettability of the working fluid and the capillary core surface, avoiding liquid aggregation or interruption. During the entire cycle, the biomass aerogel capillary core 2 evenly distributes heat through efficient liquid reflux and vapor diffusion. The phase change cycle is continuously carried out, so that the heat is quickly transferred from the evaporation end shell plate 1 to the condensation end shell plate 2, realizing the efficient heat dissipation requirements of the heat spreader.

[0041] In a specific embodiment, the method for preparing the biomass aerogel capillary wick comprises the following steps: S1. Dissolve chitosan in acetic acid solution to obtain a chitosan solution.

[0042] S2. Add the cellulose solution to the chitosan solution, cross-link at 55°C to 65°C to obtain an aerogel precursor, and freeze-dry the aerogel precursor to obtain a biomass aerogel capillary core.

[0043] In a specific embodiment, the volume ratio of the chitosan solution to the cellulose solution is 1:1, the concentration of the chitosan solution is 2 wt.% to 2.4 wt.%, and the concentration of the cellulose solution is 1 wt.% to 1.2 wt%; the cross-linking time is 1.5 h to 3 h, and the freeze-drying temperature is -60 ° C, and the time is 24 h to 48 h. It should be noted that the freeze-drying time is determined according to the thickness of the biomass aerogel capillary core, generally between 24 h and 48 h.

[0044] The biomass aerogel capillary core prepared by the present invention selects natural polymer biomass materials. Both chitosan and cellulose have rich hydrophilic groups, which give the aerogel capillary core lyophilic properties, strengthen the wettability of the working fluid on the surface and inside of the capillary core, ensure that the working fluid is more evenly distributed in the evaporation area, and reduce local hot spots. Traditional capillary core materials (such as sintered copper) are slightly inferior in working fluid wettability and may have the risk of local drying up. Made of chitosan and cellulose through freeze-drying, the porosity is as high as more than 95%, and the interior is filled with evenly distributed micropores (average pore size of about 50 μm), which significantly enhances the capillary driving force and can drive the condensed liquid to quickly return to the evaporation area. At the same time, the uniformity of the microporous structure avoids the flow dead zone and liquid reflux resistance caused by uneven pore size of traditional metal capillary cores, making the working fluid flow more smoothly inside and preventing the occurrence of local drying up. During the freeze-drying process, a certain number of macropores (pore size greater than 200 μm) are formed in the aerogel capillary core, which together with the micropores form a multi-scale pore structure: the macropores are responsible for rapid liquid reflux, and the small pores provide high capillary driving force; this multi-scale structure achieves a dynamic balance between the capillary driving force and the reflux speed, and optimizes the circulation path of the working fluid. In addition, the aerogel capillary core can be processed into different shapes and thicknesses through simple processes to meet the diverse design requirements of heat sinks, effectively solving the development needs of various thin heat sinks and even flexible heat sinks.

[0045] In a specific embodiment, Figure 3 to Figure 6 As shown, the upper surface of the biomass aerogel capillary core 2 is provided with a groove 4, and the space formed between the groove and the condensation end shell plate 3 is used for the flow of steam and condensate. The depth of the groove 4 and the height of the biomass aerogel capillary core 2 are in a ratio of 1:4 to 5, and the length and width are in a ratio of 1:0.4 to 4.5 to the length and width of the biomass aerogel capillary core 2. In this embodiment, the length × width × height of the biomass aerogel capillary core is l 2× l 2× h 4. Both length and width are l 2=90 mm, the overall height is h 4=10 mm; the length × width × height dimensions of groove 4 are l 3× l3× h 5, length and width are l 3=70 mm, internal height is h 5=5 mm, the width of the border of the biomass aerogel capillary core 2 is l 4 , that is, the distance between the inner wall of the groove 4 and the edge of the corresponding biomass aerogel capillary core 3, and the width is l 4 =5 mm, the convex part of the groove 4 is to allow the condensed liquid to reflux, and the concave groove is the steam space. The size of the groove 4 is designed to maintain a certain steam space, reduce the steam pressure drop, and allow the working fluid to evaporate and smoothly and with little resistance to contact the condensation area to liquefy into liquid and release heat. The raised frame parts on the four sides can quickly absorb the condensed liquid to return to the evaporation area. If the groove is too small, the steam space will not be enough. If the convex frame around is too small, the liquid delivery capacity is poor. This is a balance. In order to make the vaporization-liquefaction cycle of the heat spreader run perfectly. The frame of the biomass aerogel capillary core 2 fits tightly with the inner wall of the condensation end shell plate 3 for high-speed reflux of the condensate.

[0046] In a specific embodiment, the height ratio of the evaporation end shell plate 1, the biomass aerogel capillary core 2 and the condensation end shell plate 3 is 14:10:3-5, and the length ratio or width ratio is 90-95:90:90-95. Figure 11 to Figure 13 As shown, the length × width × height dimensions of the condensing end shell plate 3 are l 5× l 5× h 6, length and width are l 5=90 mm, the overall height is h 6=4 mm.

[0047] In a specific embodiment, Figure 7 to Figure 10 As shown, the evaporation end shell plate 1 is a frame structure, and a plurality of support columns 5 are evenly distributed in the frame structure. 5 The spacing between them is 8mm to 12mm, and the height ratio of all support columns 5 to the height of the evaporation end shell plate 1 is 10:13 to 15. In this embodiment, the frame structure is a cubic structure, and the length × width × height dimensions of the evaporation end shell plate 1 are l 1× l 1× h 1. Both length and width are l 1=92 mm, the overall height is h 1=14 mm, the number of support columns 5 is 81, and the length × width × height dimensions of a single support column 5 are w 1× w 1× h 2. The length and width are w1=2 mm, height is h 2=10 mm, the support column 5 plays a supporting role and a heat conduction role, that is, the support column 5 can not only maintain the supporting capacity, but also maintain a good steam space. As mentioned above, it reduces the steam pressure drop and allows the steam to flow better to the condensation area and condense into liquid.

[0048] In a specific embodiment, the biomass aerogel capillary core 2 is inserted into all the support columns 5, and the lower wall of the biomass aerogel capillary core 2 contacts the inner wall of the evaporation end shell plate 1, and the upper ends of all the support columns 5 contact the inner wall of the condensation end shell plate 3. In this embodiment, the biomass aerogel capillary core 2 is aerogel and has deformability. After all the support columns 5 are directly inserted into the biomass aerogel capillary core 2, they contact the inner wall of the condensation end shell plate 3, thereby increasing the close fit between all the support columns 5 and the biomass aerogel capillary core 2.

[0049] The space formed between the evaporation end shell plate 1 and the support columns 5 is used to place the biomass aerogel capillary core 2 . After the biomass aerogel capillary core 2 is inserted into all the support columns 5 , it contacts the inner wall of the evaporation end shell plate 1 .

[0050] In a specific embodiment, the cross section of the support column 5 is square, circular or diamond-shaped. In this embodiment, the cross section of the support column 5 is square.

[0051] In a specific embodiment, a side wall of the evaporation end shell plate 1 is provided with a liquid injection port 7. In this embodiment, the outer diameter of the liquid injection port is d 1=5 mm, inner diameter size is d 2=4 mm, height is h 3=5 mm.

[0052] In summary, the present invention discloses a heat spreader based on a chitosan-cellulose composite biomass aerogel capillary core, which mainly includes an evaporation end shell plate, a biomass aerogel and a condensation end shell plate. It is made by fine carving and freeze-drying technology. During the entire operation process, the heat source transfers heat to the biomass aerogel capillary core through the evaporation end shell plate. The capillary core quickly absorbs heat due to its high porosity and lyophilicity, and converts the liquid working fluid into steam. During the evaporation process, the liquid working fluid quickly absorbs heat at the microporous interface of the capillary core to form latent heat of phase change, so that the temperature of the evaporation end can be reduced. The steam diffuses to the condensation end shell plate through the channel inside the heat spreader. At the condensation end, the steam releases heat and condenses into a liquid working fluid after contacting the surface of the shell plate. At the same time, the condensation end shell plate efficiently transfers the heat to the external heat dissipation system (such as air cooling or water cooling device) to dissipate the heat to the environment. The liquid working fluid formed by condensation flows back to the evaporation area through the porous network of the capillary core under the action of capillary driving force. The multi-scale pore structure optimizes the liquid flow path, the large pores accelerate the reflux of the liquid, and the small pores provide sufficient capillary driving force. The porous network of the biomass aerogel capillary core makes the liquid and steam evenly distributed, avoids the generation of local hot spots, and ensures uniform heat distribution in the heat spreader. The entire phase change cycle of evaporation, diffusion, condensation and reflux is carried out efficiently, ensuring the uniform distribution of heat inside the heat spreader, significantly improving the heat dissipation efficiency, and being able to meet the stringent requirements of high heat flux density equipment for heat dissipation performance. The present invention has the advantages of high heat dissipation performance, lightweight, low cost, and green environmental protection, and can be used to meet the heat dissipation needs of high-power chips, lightweight equipment needs, and green product design needs.

[0053] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0054] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A heat spreader with a biomass aerogel capillary core, characterized in that: The invention comprises an evaporation end shell plate (1), a biomass aerogel capillary core (2) and a condensation end shell plate (3) which are arranged in sequence from bottom to top in a vertical direction. The biomass aerogel capillary core (2) is located in a closed cavity formed by the evaporation end shell plate (1) and the condensation end shell plate (3). The biomass aerogel capillary core (2) is in contact with the evaporation end shell plate (1) and the condensation end shell plate (3). The biomass aerogel capillary core (2) is a chitosan-cellulose aerogel capillary core, and the porosity of the chitosan-cellulose aerogel capillary core is greater than 95%.

2. The heat sink of the biomass aerogel capillary wick according to claim 1, characterized in that: The preparation method of the biomass aerogel capillary core comprises the following steps: Dissolving chitosan in an acetic acid solution to obtain a chitosan solution; The cellulose solution is added into the chitosan solution, and cross-linking is performed at 55°C to 65°C to obtain an aerogel precursor, and the aerogel precursor is freeze-dried to obtain a biomass aerogel capillary core.

3. The heat sink of the biomass aerogel capillary wick according to claim 2, characterized in that: The volume ratio of the chitosan solution to the cellulose solution is 1:1, the concentration of the chitosan solution is 2 wt.% to 2.4 wt.%, and the concentration of the cellulose solution is 1 wt.% to 1.2 wt%; the cross-linking time is 1.5 h to 3 h, and the freeze-drying temperature is -60 ° C, and the time is 24 h to 48 h.

4. The heat sink of the biomass aerogel capillary wick according to claim 1, characterized in that: The upper surface of the biomass aerogel capillary core (2) is provided with a groove (4), and the space formed between the groove (4) and the condensation end shell plate (3) is used for the flow of steam and condensate.

5. The heat sink of the biomass aerogel capillary wick according to claim 4, characterized in that: The ratio of the depth of the groove (4) to the height of the biomass aerogel capillary core (2) is 1:4-5, and the ratio of the length and width of the groove (4) to the length and width of the biomass aerogel capillary core (2) is 1:0.4-4.

5.

6. The biomass aerogel capillary core heat sink according to claim 1, characterized in that: The height ratio of the evaporation end shell plate (1), the biomass aerogel capillary core (2) and the condensation end shell plate (3) is 14:10:3-5, and the length ratio or width ratio is 90-95:90:90-95.

7. The heat sink of the biomass aerogel capillary wick according to claim 1, characterized in that: The evaporation end shell plate (1) is a frame structure, a plurality of support columns (5) are evenly distributed in the frame structure, the spacing between adjacent support columns (5) is 8 mm to 12 mm, and the ratio of the height of all the support columns (5) to the height of the evaporation end shell plate (1) is 10:13 to 15.

8. The heat sink of the biomass aerogel capillary wick according to claim 6, characterized in that: The biomass aerogel capillary core (2) is inserted into all the support columns (5), and the lower wall of the biomass aerogel capillary core (2) is in contact with the inner wall of the evaporation end shell plate (1), and the upper ends of all the support columns (5) are in contact with the inner wall of the condensation end shell plate (3).

9. The heat sink of the biomass aerogel capillary wick according to claim 6, characterized in that: The cross section of the support column (5) is square, circular or diamond-shaped.

10. The biomass aerogel capillary core vapor chamber according to claim 1, characterized in that: A liquid injection port (6) is provided on one side wall of the evaporation end shell plate (1).

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