A tree-shaped heat pipe

Abstract

The invention discloses a tree-shaped heat pipe, comprising a heat pipe shell, a capillary wick, a coolant and a plurality of tree-shaped structures; the heat pipe shell is a sealed shell, the tree-shaped structure sequentially passes through the evaporation section and the condensation section, and is attached to the inner wall of the heat pipe shell; a capillary wick and a coolant are provided in the evaporation section, the capillary wick is connected to the tree-shaped structure, and in the condensation section, except for the area occupied by the tree-shaped structure, other areas are super-liquid-repellent surface areas, and the tree-shaped structure is a super-liquid-loving surface area. The present invention uses a tree-shaped structure to coordinate super-liquid-repellent and super-liquid-loving interlaced mode, and utilizes a super-liquid-repellent surface to accelerate the cooling speed, and the super-liquid-loving surface attracts the liquid droplets condensed on the super-liquid-repellent surface, so that the tree-shaped heat pipe can realize the rapid transmission of the coolant, and effectively prevent the liquid droplets from affecting the heat exchange of the super-liquid-repellent surface. At the same time, the tree-shaped structure can reduce the flow resistance of the coolant on the super-liquid-loving surface, so that the coolant can quickly flow back to the heat pipe evaporation section, and improve the critical heat flux density of the heat pipe.

Description

Technical Field

[0001] The invention relates to the field of efficient heat dissipation of electronic devices, and in particular to a heat pipe with a tree structure. Background Art

[0002] With the development of micro-electromechanical system technology, the integration and high frequency of electronic devices are constantly improving, the characteristic size is constantly decreasing, the heat generation per unit volume is constantly increasing, and the compact design of the equipment makes heat dissipation more difficult. Therefore, it is urgent to solve the problem of efficient heat dissipation technology. Traditional air cooling and liquid convection heat transfer technology is difficult to take away a large amount of heat in time, causing the temperature of electronic devices to rise, greatly reducing their practicality and reliability. Therefore, the heat dissipation technology of high heat flux in small space has become one of the key factors restricting information, electronics, aerospace and military technology.

[0003] As a phase change heat transfer method, heat pipe has significantly improved heat transfer coefficient and very small heat transfer resistance compared with traditional air cooling and liquid convection heat transfer. It can transmit a large amount of heat through a small cross-sectional area over a long distance without external power, which is a very effective heat dissipation method. However, the current critical heat flux density of heat pipes still cannot meet the heat dissipation requirements of high-end electronic devices. The main reasons for limiting the critical heat flux density of heat pipes are the cooling speed of the heat pipe condensation end, the return capacity of the capillary wick, and the steam flow resistance. The most important limiting factor is the return capacity of the capillary wick. In addition, traditional heat pipes are relatively long, and the coolant is returned entirely by the wick close to the pipe wall. Too long heat pipes further limit the return rate. When the evaporation rate of the coolant in the evaporation section is greater than the return rate of the wick, the heat pipe will enter a dry burning state, and the temperature will increase rapidly, causing the heat pipe to fail. This makes the current critical heat flux density of heat pipes still unable to meet the heat dissipation requirements of high-end electronic devices. Summary of the invention

[0004] In view of the above technical defects and application requirements, an embodiment of the present invention provides a tree-shaped structure heat pipe to overcome the defect that the critical heat flux density of the traditional heat pipe is difficult to increase due to the limited liquid return capacity of the liquid absorption core.

[0005] In order to solve the above problems, the present invention provides a tree-shaped heat pipe, comprising: a heat pipe shell, a capillary wick, a coolant and a plurality of tree-shaped structures;

[0006] The heat pipe shell is a sealed shell, and an evaporation section and a condensation section are arranged in the heat pipe shell; the evaporation section and the condensation section are connected to each other; the tree-shaped structure passes through the evaporation section and the condensation section in sequence, and is attached to the inner wall of the heat pipe shell;

[0007] The capillary wick and the coolant are arranged in the evaporation section, and the capillary wick is connected with the tree structure; except for the area occupied by the tree structure, the other areas in the condensation section are super liquid-repellent surface areas; and the tree structure is a super liquid-philic surface area.

[0008] Furthermore, an insulating section is provided in the heat pipe shell; the insulating section is arranged between the evaporation section and the condensation section, and the evaporation section is connected with the condensation section through the insulating section; the tree structure passes through the evaporation section, the insulating section and the condensation section in sequence.

[0009] Furthermore, except for the area occupied by the tree-shaped structure, the rest of the area in the thermal insulation section is the super-liquid-repellent surface area.

[0010] Furthermore, the condensation section, the insulation section and the evaporation section are connected in sequence from top to bottom.

[0011] Furthermore, the tree-shaped structure is vertically or obliquely attached to the inner wall of the heat pipe shell.

[0012] Furthermore, the tree-shaped structure starts from the evaporation section, gradually branches upward, and the channel of each branch gradually decreases until it reaches the condensation section.

[0013] Furthermore, each branch channel is arranged above the horizontal direction.

[0014] Furthermore, the minimum size of the branch channel is micrometer-scale or nanometer-scale.

[0015] Furthermore, the capillary wick is arranged on the inner wall of the evaporation section.

[0016] Furthermore, the heat pipe shell is a rectangular parallelepiped structure or a cylindrical structure.

[0017] The tree-shaped heat pipe provided by the present invention uses a tree-shaped structure in combination with a super-lyophobic and super-lyophilic alternating mode, uses a super-lyophobic surface to accelerate the cooling speed, and the super-lyophilic surface attracts the liquid droplets condensed on the super-lyophobic surface, so that the liquid droplets can be spread along the super-lyophilic surface, so that the tree-shaped heat pipe can realize the rapid transmission of the cooling liquid, and effectively prevent the liquid droplets from affecting the heat exchange of the super-lyophobic surface. At the same time, the tree-shaped structure can reduce the flow resistance of the cooling liquid on the super-lyophilic surface, so that the cooling liquid can quickly flow back to the evaporation section of the heat pipe, and improve the critical heat flux density of the heat pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic cross-sectional view of a tree-shaped heat pipe provided in an embodiment of the present invention;

[0020] Figure 2 A top view of a tree-shaped heat pipe provided in an embodiment of the present invention;

[0021] Explanation of the accompanying drawings: 1. heat pipe shell; 2. capillary wick; 3. cooling liquid; 4. super liquid-phobic surface area; 5. super liquid-philic surface area; 6. tree-like structure. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The embodiment of the present invention provides a tree-shaped heat pipe, such as Figure 1As shown, the tree-shaped heat pipe comprises: a heat pipe shell 1, a capillary wick 2, a coolant 3 and a plurality of tree-shaped structures 6. The heat pipe shell 1 is a sealed shell, and an evaporation section and a condensation section are arranged in the heat pipe shell 1. The evaporation section and the condensation section are connected to each other. The tree-shaped structure 6 passes through the evaporation section and the condensation section in sequence, and the tree-shaped structure 6 is attached to the heat pipe shell 1. The evaporation section is provided with a capillary wick 2 and a coolant 3, and the capillary wick 2 is connected to the tree-shaped structure 6. Except for the area of ​​the tree-shaped structure 6 in the condensation section, the other areas are super-liquid-repellent surface areas 4, and the tree-shaped structure is a super-liquid-philic surface area 5, that is, the other areas around the tree-shaped structure 6 in the condensation section are all super-liquid-repellent surface areas 4. The capillary wick 2 is used to distribute the coolant 3 in the evaporation section.

[0025] When the tree-shaped heat pipe provided in this embodiment works normally, the evaporation section in the heat pipe shell 1 is tightly fitted with the heat source, the evaporation section of the heat pipe shell 1 absorbs heat from the heat source, and conducts the heat to the capillary wick 2 in the evaporation section, and then transfers the heat to the coolant 3 immersed in the capillary wick 2, so that the coolant 3 boils and evaporates, and the steam moves upward, and quickly condenses into liquid droplets in the super-lyophobic surface area 4 of the condensation section. The condensed tiny liquid droplets move to the super-lyophilic surface area 5 under the attraction of the super-lyophilic surface area 5 of the tree-shaped structure 6, and gather in the super-lyophilic surface area 5. Afterwards, due to the characteristics of the super-lyophilic surface area 5, they will quickly spread in the super-lyophilic surface area 5, so that the cooling liquid droplets are continuously adsorbed into the tree-shaped structure 6, and are transported back to the capillary wick 2 of the evaporation section through the tree-shaped structure 6 for heat absorption and evaporation again, completing the entire heat exchange cycle.

[0026] The coolant filled in the evaporation section has a certain vacuum degree, and the filling rate and vacuum degree can be determined according to actual use requirements. The cooling of the condensation section can be done by external forced air cooling or liquid cooling. If you want to speed up the cooling of the condensation section, you can choose liquid cooling.

[0027] The tree-shaped heat pipe provided by the embodiment of the present invention uses a tree-shaped structure in combination with a super-lyophobic and super-lyophilic alternating mode, uses a super-lyophobic surface to accelerate the cooling speed, and the super-lyophilic surface attracts the liquid droplets condensed on the super-lyophobic surface, so that the liquid droplets can be spread along the super-lyophilic surface, so that the tree-shaped heat pipe can achieve rapid transmission of the cooling liquid, and effectively prevent the liquid droplets from affecting the heat exchange of the super-lyophobic surface. At the same time, the tree-shaped structure can further reduce the flow resistance of the cooling liquid on the super-lyophilic surface, so that the cooling liquid can quickly flow back to the evaporation section of the heat pipe, and improve the critical heat flux density of the heat pipe.

[0028] Based on the above embodiments, in a preferred embodiment, Figure 1As shown, an insulating section is also provided in the heat pipe shell. The insulating section is arranged between the evaporation section and the condensation section, and the evaporation section is connected to the condensation section through the insulating section. The tree structure 6 passes through the evaporation section, the insulating section and the condensation section in sequence and is arranged in the heat pipe shell. The insulating section is the middle end between the insulating section and the condensation section and is mainly used to transfer heat.

[0029] In this embodiment, in order to allow some condensed liquid droplets in the insulation section to be quickly adsorbed into the tree-shaped structure 6, the other areas in the insulation section except the area of ​​the tree-shaped structure 6 are super-liquid-repellent surface areas 4, that is, the insulation section and the condensation section both adopt the design of the tree-shaped structure 6 with alternating super-liquid-repellent and super-liquid-philic, and the other areas around the tree-shaped structure 6 in the insulation section are super-liquid-repellent surface areas 4, so that some steam liquid droplets entering the insulation section can also converge to the super-liquid-philic surface area 5 of the tree-shaped structure 6.

[0030] Since the present embodiment adopts the tree-shaped structure 6, the heat pipe of this structure is not suitable for horizontal use, but mainly suitable for inclined and vertical use. Therefore, in the present embodiment, the condensation section, the insulation section and the evaporation section are connected in sequence from top to bottom. The tree-shaped structure 6 is attached vertically or inclined in the heat pipe housing 1.

[0031] The tree structure 6 starts from the evaporation section, gradually branches upward, and the channels of each branch gradually decrease until the condensation section. The channel size of the branch can be as small as micrometer or nanometer. The tree structure 6 starts from the evaporation section of the heat pipe, and several main channels can be set, that is, multiple tree structures 6 are arranged around the heat pipe at the same time, and tree branches are formed based on each main channel.

[0032] Furthermore, the branch direction of the tree structure is upward as a whole, that is, the channels of each branch are arranged above the horizontal direction, and it is not suitable for the channel development of the branch to be downward. This is because the function of the branch channel is mainly to transport the coolant in it to the upper channel, and finally converge in the main channel and return to the evaporation section. If the branch channel develops upward, the effect of gravity can be used to further increase the reflux speed, otherwise it will reduce the liquid return speed.

[0033] like Figure 2 As shown, in this embodiment, the heat pipe housing 1 is a cylindrical structure. According to different heat dissipation requirements, the heat pipe housing 1 can also adopt a rectangular structure, and the specific shape can also be designed according to needs.

[0034] In order to ensure that the cooling liquid is evenly distributed on the entire evaporation section wall, a capillary wick 2 can be arranged on the inner wall of the evaporation section to transfer the cooling liquid that flows back to the evaporation section on the wall of the evaporation section.

[0035] When the tree-shaped heat pipe provided in the embodiment works normally, the evaporation section in the heat pipe housing 1 is closely attached to the heat source, the evaporation section of the heat pipe housing 1 absorbs heat from the heat source, and conducts the heat to the capillary wick 2 in the evaporation section, and then transfers the heat to the coolant 3 immersed in the capillary wick 2, so that the coolant 3 boils and evaporates, and the steam moves upward, and is quickly condensed into liquid droplets in the super-lyophobic surface area 4 of the condensation section. The condensed tiny liquid droplets are attracted by the super-lyophilic surface area 5 of the tree-shaped structure 6 and move to the super-lyophilic surface area 5. Move, and gather in the super-lyophilic surface area 5, and then due to the characteristics of the super-lyophilic surface area 5, it will quickly spread in the super-lyophilic surface area 5, so that the cooling liquid beads are continuously adsorbed to the super-lyophilic surface area 5 of the tree structure 6, enter the branch channel, and are quickly transported to the main channel of the tree structure 6 step by step for convergence, so that the cooling liquid beads are continuously adsorbed to the tree structure 6, and are used for heat absorption and evaporation again in the capillary liquid absorption core 2 transported back to the evaporation section through the tree structure 6, completing the entire heat exchange cycle. Since the channel of the tree structure 6 reduces the fluid flow resistance, the bead condensation of the super-lyophilic surface area 4 improves the cooling capacity, and the rapid spreading characteristics of the liquid in the super-lyophilic surface area 5 accelerate the return speed of the cooling liquid 3, thereby effectively improving the critical heat flux density of the heat pipe.

[0036] In summary, the tree-shaped heat pipe provided by the embodiment of the present invention uses a tree-shaped structure in combination with a super-lyophobic and super-lyophilic alternating mode, uses a super-lyophobic surface to accelerate the cooling speed, and the super-lyophilic surface attracts the liquid droplets condensed on the super-lyophobic surface, so that the liquid droplets can be laid along the super-lyophilic surface, so that the tree-shaped heat pipe can achieve rapid transmission of the cooling liquid, and effectively prevent the liquid droplets from affecting the heat exchange of the super-lyophobic surface. At the same time, the design of the tree-shaped structure can further reduce the flow resistance of the cooling liquid on the super-lyophilic surface, so that the cooling liquid can quickly flow back to the evaporation section of the heat pipe, and improve the critical heat flux density of the heat pipe.

[0037] In addition, the tree-shaped structure heat pipe provided in the embodiment of the present invention is different from the traditional heat pipe. In addition to the capillary wick being arranged on the inner wall surface of the evaporation section, the tree-shaped structure heat pipe of the present invention does not need to be provided with a capillary wick on the inner wall surface of the insulation section and the condensation section. Instead, a super-lyophilic-super-lyophobic phase design of the tree-shaped structure is used.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the invention rather than to limit it. Although the invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the invention.

Claims

1. A tree-shaped heat pipe, characterized in that: include: A heat pipe housing, a capillary wick, a coolant and a plurality of tree structures; The heat pipe shell is a sealed shell, and an evaporation section and a condensation section are arranged in the heat pipe shell; The evaporation section and the condensation section are interconnected; the tree-shaped structure passes through the evaporation section and the condensation section in sequence and is attached to the inner wall of the heat pipe shell; The capillary wick and the coolant are provided in the evaporation section, and the capillary wick is connected to the tree-shaped structure; except for the area occupied by the tree-shaped structure in the condensation section, the other areas are super-liquid-repellent surface areas; the tree-shaped structure is a super-liquid-philic surface area; an insulating section is also provided in the heat pipe shell; the insulating section is arranged between the evaporation section and the condensation section, and the evaporation section is connected to the condensation section through the insulating section; the tree-shaped structure passes through the evaporation section, the insulating section and the condensation section in sequence, and except for the area occupied by the tree-shaped structure in the insulating section, the other areas are the super-liquid-repellent surface areas, and the condensation section, the insulating section and the evaporation section are connected in sequence from top to bottom.

2. The tree-shaped heat pipe according to claim 1, characterized in that: The tree-shaped structure is vertically or obliquely attached to the inner wall of the heat pipe shell.

3. The tree-shaped heat pipe according to claim 1, characterized in that: The tree-shaped structure starts from the evaporation section, gradually branches upward, and the channel of each branch gradually decreases until it reaches the condensation section.

4. The tree-shaped heat pipe according to claim 3, characterized in that: The minimum dimension of the branched channels is nanometer scale.

5. The tree-shaped heat pipe according to any one of claims 1 to 4, characterized in that: The capillary wick is arranged on the inner wall of the evaporation section.

6. The tree-structured heat pipe according to any one of claims 1 to 4, characterized in that: The heat pipe shell is a rectangular parallelepiped structure or a cylindrical structure.

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