Capillary phase change heat pipe device

Abstract

The invention discloses a capillary phase change heat pipe device, and belongs to the field of heat pipes, the capillary phase change heat pipe device comprises a heat pipe, the heat pipe comprises an outer pipe body and an inner pipe body arranged in the outer pipe body, the heat pipe is divided into an evaporation section, a heat insulation section and a condensation section, the heat insulation section is located between the evaporation section and the condensation section, and the inner pipe is located at the heat insulation section; the inner wall of the outer pipe body is provided with a composite capillary structure and a plurality of grooves used for reducing backflow resistance of a liquid working medium in the heat pipe, the grooves are evenly distributed in the circumferential direction of the inner wall of the outer pipe body, and each groove is formed in the axial direction of the outer pipe body and transversely penetrates through the whole inner wall face in the length direction of the outer pipe body. The composite capillary structure is arranged on the groove and comprises a first capillary structure and a second capillary structure, and the first capillary structure is arranged on the second capillary structure. According to the capillary phase change heat pipe device, the heat exchange efficiency of the capillary phase change heat pipe is improved from the three aspects of heat pipe structure improvement, wick design and surface treatment.

Description

Technical Field

[0001] The invention relates to the technical field of heat pipes, and in particular to a capillary phase change heat pipe device. Background Art

[0002] A heat pipe is a device that uses the phase change (evaporation and condensation) of a liquid to transfer heat. It is usually composed of a sealed tube body and a working medium filled inside. Traditional heat pipes rely on the evaporation and condensation process of the working medium to achieve heat transfer. The efficient heat transfer performance of heat pipes stems from their phase change process, but in some cases, traditional heat pipes may be affected by factors such as gravity and space limitations due to liquid reflux and the flow of the working medium, resulting in reduced heat transfer efficiency.

[0003] Capillary Phase Change Heat Pipe (CPCHP) is a heat pipe device that uses capillary structure and phase change principle to achieve efficient heat conduction. It combines the advantages of traditional heat pipes and optimizes heat transfer performance by introducing capillary force in structural design. Therefore, it has been widely used in some high-efficiency heat dissipation applications. Especially in those environments that require efficient heat dissipation and have large space constraints: such as electronic equipment heat dissipation; aerospace; solar thermal utilization; industrial equipment cooling and other fields.

[0004] Nowadays, heat transfer plays an important role in daily life and industrial production. With the improvement of productivity, various industries have higher and higher requirements for heat dissipation, and it is urgent to improve the heat transfer power of heat pipes. The existing heat pipes still have insufficient heat transfer capacity, so it is necessary to improve the heat transfer capacity of heat pipes from three aspects: improving the heat pipe structure, designing the liquid absorption core, and surface treatment. Summary of the invention

[0005] The purpose of the present invention is to provide a capillary phase change heat pipe device, which improves the heat exchange efficiency of the capillary phase change heat pipe from three aspects: heat pipe structure improvement, liquid wick design, and surface treatment.

[0006] To achieve the above object, the present invention provides a capillary phase change heat pipe device, comprising a heat pipe, the heat pipe comprising an outer tube body and an inner tube body arranged inside the outer tube body, the heat pipe is divided into an evaporation section, an insulation section and a condensation section, the insulation section is located between the evaporation section and the condensation section, and the inner tube is located at the insulation section; The inner wall of the outer tube body is provided with a composite capillary structure and a plurality of grooves for reducing the reflux resistance of the liquid working medium in the heat pipe. The plurality of grooves are evenly arranged along the circumference of the inner wall of the outer tube body. Each groove is arranged along the axial direction of the outer tube body and crosses the entire inner wall surface of the outer tube body in the length direction. The composite capillary structure is arranged on the groove, and the composite capillary structure comprises a capillary structure 1 and a capillary structure 2, wherein the capillary structure 1 is arranged on the capillary structure 2.

[0007] Preferably, the inner tube body is arranged on the capillary structure, and the inner tube body is used to separate the working medium vapor channel and the liquid wick channel at the insulation section to form an inner transmission channel and an outer transmission channel.

[0008] Preferably, the capillary structure 1 is stacked on the capillary structure 2, and the capillary structure 2 is located on the inner wall surface of the outer tube.

[0009] Preferably, the capillary structure 1 and the capillary structure 2 are two layers of metal meshes with different porosities.

[0010] Preferably, the thickness of the capillary structure one is equal to the thickness of the capillary structure two, and the porosity of the capillary structure two is less than the porosity of the capillary structure one.

[0011] Preferably, the outer tube body and the groove are integrally formed.

[0012] Preferably, the shape of the groove is triangle, rectangle, trapezoid or semicircle.

[0013] Preferably, the inner surface of the groove is coated with a hydrophobic material.

[0014] Preferably, the inner wall surface of the inner tube is coated with a hydrophilic material.

[0015] Preferably, the outer wall of the inner tube is coated with a hydrophobic material.

[0016] Therefore, the present invention adopts a capillary phase change heat pipe device with the above structure, which has the following beneficial effects: (1) The groove structure provided on the inner wall of the heat pipe of the present invention can increase the evaporation surface area of ​​the liquid working medium in the evaporation section and the heat dissipation area in the condensation section, thereby increasing the capillary force of the capillary structure and having a higher porosity, which is conducive to the rapid reflux of the condensed liquid; the double-layer capillary wick sintered by the metal woven mesh has a small capillary radius, and the porosity of the capillary structure 1 and the capillary structure 2 are different, so that the capillary structure has both large capillary force and permeability, thereby solving the contradiction between the capillary force of the capillary structure and the reflux resistance of the working medium; (2) The present invention adds an inner tube to the heat pipe insulation section to isolate the working fluid vapor from the reflux condensate, thereby reducing the mutual resistance between the two and accelerating the circulation of the working fluid inside the heat pipe; (3) The present invention coats the inner wall of the heat pipe and the outer wall of the inner tube with a hydrophobic material, and coats the inner wall of the inner tube with a hydrophilic material, so that the condensate can quickly reflux and accelerate the evaporation of the liquid working fluid, thereby improving the heat exchange efficiency of the capillary phase change heat pipe.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A cross-sectional view of a capillary phase change heat pipe according to an embodiment of the present invention; Figure 2 It is a three-dimensional schematic diagram of a capillary phase change heat pipe according to an embodiment of the present invention; Figure 3 for Figure 1 A partial enlarged schematic diagram of Figure 4 For along Figure 1 A schematic cross-sectional view drawn by the 2-2 cut line; Figure 5 For along Figure 1 Schematic diagram of the cross section drawn by the 3-3 cutting line.

[0019] Reference numerals 10. Heat pipe; 11. Outer tube body; 111. Inner tube body; 12. Inner tube body; 121. Inner tube body surface; 122. Inner tube body surface; 101. Groove structure; 110. Evaporation section; 120. Insulation section; 130. Condensation section; 200. Evaporation section end cover; 300. Condensation section end cover; 13. Composite capillary structure; 131. Capillary structure one; 132. Capillary structure two; 140. Inner transmission channel; 150. Outer transmission channel. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0021] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or devices.

[0022] Like reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0024] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" 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 an indirect connection 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.

[0025] Example like Figures 1 to 3 As shown, a capillary phase change heat pipe 10 device according to the present invention comprises a heat pipe 10, wherein the heat pipe 10 comprises an outer tube body 11 and an inner tube body 12 disposed inside the outer tube body 11. The heat pipe 10 is divided into an evaporation section 110, an insulation section 120 and a condensation section 130, wherein the insulation section 120 is located between the evaporation section 110 and the condensation section 130, and the inner tube is located at the insulation section 120. Both the outer tube body 11 and the inner tube body 12 are made of high temperature and high pressure resistant metal materials, such as copper alloy materials, etc., which can extend the service life of the heat pipe 10.

[0026] The working fluid that can be used for the heat pipe 10 in the embodiment of the present invention is water, an organic liquid (such as some paraffins) or a metal vapor (such as sodium, cesium, etc.).

[0027] The inner wall of the outer tube body 11 is provided with a composite capillary structure 13 and a plurality of grooves for reducing the reflux resistance of the liquid working medium in the heat pipe 10. The composite capillary structure 13 is arranged on the groove, and the inner tube body 12 is arranged on the capillary structure. The inner tube body 12 is used to separate the working medium vapor channel and the liquid wick channel at the insulation section 120 to form an inner transmission channel 140 and an outer transmission channel 150. The inner tube body 12 isolates the working medium vapor from the reflux condensate, reduces the mutual resistance between the two, and accelerates the circulation of the working medium inside the heat pipe 10; the present invention coats the inner surface 121 of the inner tube body with a hydrophilic material to accelerate the evaporation of the liquid working medium and the circulation speed of the working medium vapor; at the same time, the inner surface 122 of the inner tube body is coated with a hydrophobic material to allow the condensate to reflux quickly, thereby improving the heat exchange power of the capillary phase change heat pipe 10.

[0028] like Figures 1 to 3As shown, the material of the composite capillary structure 13 is stainless steel or copper metal mesh. In this embodiment. The composite capillary structure 13 is composed of two layers of metal meshes with different mesh sizes, namely capillary structure 1 131 and capillary structure 2 132. Capillary structure 1 131 is stacked on capillary structure 2 132. Capillary structure 2 132 is located on the inner wall surface of the outer tube body 11. Capillary structure 1 131 and capillary structure 2 132 have different porosities. The thickness of capillary structure 1 131 is equal to the thickness of capillary structure 2 132. The porosity of capillary structure 2 132 is less than the porosity of capillary structure 1 131, so that the capillary structure has greater capillary force and permeability.

[0029] like Figures 4 to 5 As shown, a plurality of grooves are evenly arranged along the circumference of the inner wall of the outer tube body 11, and each groove is arranged along the axial direction of the outer tube body 11 and crosses the entire inner wall surface of the outer tube body 11 in the length direction. The outer tube body 11 and the groove are integrally formed, and the shape of the groove is triangular, rectangular, trapezoidal or semicircular, etc. In this embodiment, the shape of the groove is triangular, the number of grooves can be 24, and the depth of the groove is 2mm. The groove structure 101 can increase the evaporation surface area of ​​the liquid working medium in the evaporation section 110, increase the heat dissipation area of ​​the condensation section 130, increase the capillary force of the composite capillary structure 13, and have a higher porosity, thereby improving the heat exchange efficiency of the heat pipe 10.

[0030] The surface of the groove structure 101, that is, the inner surface 111 of the outer tube body, is coated with a hydrophobic material, which reduces the resistance of the condensed liquid working medium flowing through the groove and accelerates the circulation of the working medium.

[0031] During the smelting process, there will be gas inside the metal. If it is not discharged in time, the gas will be slowly released and become non-condensable gas when the heat pipe 10 is running. Therefore, after the heat pipe 10 is welded, it needs to be placed in a vacuum furnace for degassing.

[0032] like Figure 1 As shown, the outer tube body 11 is provided with an evaporation section end cap 200 and a condensation section end cap 300, which are respectively located at both ends of the outer tube body 11 to seal the outer tube body 11. For heat pipes 10 with high operating temperature and high steam pressure, argon arc welding can be used to ensure good vacuum sealing and certain weld strength.

[0033] Therefore, the present invention adopts a capillary phase change heat pipe 10 device of the above structure to improve the heat exchange efficiency of the capillary phase change heat pipe 10 from three aspects: structural improvement of the heat pipe 10, liquid absorption core design, and surface treatment.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A capillary phase change heat pipe device, characterized in that: The heat pipe comprises an outer tube body and an inner tube body arranged inside the outer tube body, the heat pipe is divided into an evaporation section, an insulation section and a condensation section, the insulation section is located between the evaporation section and the condensation section, and the inner tube is located at the insulation section; The inner wall of the outer tube body is provided with a composite capillary structure and a plurality of grooves for reducing the reflux resistance of the liquid working medium in the heat pipe. The plurality of grooves are evenly arranged along the circumference of the inner wall of the outer tube body. Each groove is arranged along the axial direction of the outer tube body and crosses the entire inner wall surface of the outer tube body in the length direction. The composite capillary structure is arranged on the groove, and the composite capillary structure comprises a capillary structure 1 and a capillary structure 2, wherein the capillary structure 1 is arranged on the capillary structure 2.

2. The capillary phase change heat pipe device according to claim 1, characterized in that: The inner tube body is arranged on the capillary structure, and is used to separate the working medium steam channel and the liquid wick channel at the insulation section to form an inner transmission channel and an outer transmission channel.

3. The capillary phase change heat pipe device according to claim 1, characterized in that: The capillary structure 1 is stacked on the capillary structure 2, and the capillary structure 2 is located on the inner wall surface of the outer tube.

4. The capillary phase change heat pipe device according to claim 3, characterized in that: Capillary structure 1 and capillary structure 2 are two layers of metal mesh with different porosities.

5. The capillary phase change heat pipe device according to claim 4, characterized in that: The thickness of the capillary structure one is equal to the thickness of the capillary structure two, and the porosity of the capillary structure two is less than the porosity of the capillary structure one.

6. The capillary phase change heat pipe device according to claim 1, characterized in that: The outer tube body and the groove are formed in one piece.

7. The capillary phase change heat pipe device according to claim 6, characterized in that: The shape of the groove is triangle, rectangle, trapezoid or semicircle.

8. The capillary phase change heat pipe device according to claim 7, characterized in that: The inner surface of the groove is coated with a hydrophobic material.

9. The capillary phase change heat pipe device according to claim 1, characterized in that: The inner wall surface of the inner tube is coated with a hydrophilic material.

10. The capillary phase change heat pipe device according to claim 1, characterized in that: The outer wall surface of the inner tube body is coated with a hydrophobic material.

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