CN209978682U

CN209978682U - Heat pipe

Info

Publication number: CN209978682U
Application number: CN201920609576.6U
Authority: CN
Inventors: 周志勇
Original assignee: Shenzhen Shangyi Industrial Co Ltd
Current assignee: Shenzhen Shangyi Industrial Co Ltd
Priority date: 2019-04-29
Filing date: 2019-04-29
Publication date: 2020-01-21
Anticipated expiration: 2029-04-29

Abstract

The utility model relates to a heat transfer element technical field discloses a heat pipe, including shell, evaporation zone and condensation zone, the shell seals and the inside cavity that has, the evaporation zone with the condensation zone is located respectively the both ends of heat pipe, be equipped with a plurality of holes on the inner wall of shell in order to form porous capillary structure, just porous capillary structure's surface still is equipped with woven mesh capillary structure. The utility model provides a heat pipe can increase capillary suction when reducing radial heat transfer hindrance, can go out the heat transfer in evaporating zone as early as possible, and the liquid in the shell can flow back smoothly.

Description

Heat pipe

Technical Field

The utility model relates to a heat transfer element technical field especially relates to a heat pipe.

Background

With the increasing demands of consumers on various electronic products, the electronic products are gradually developing towards small and portable. However, after the volume of the product is reduced, the internal space of the product is also limited, the internal elements are arranged compactly, heat dissipation is not facilitated, and the problem of overheating of the elements is easy to occur. In order to solve this problem, a heat pipe is usually disposed at the position of the heat-generating element to reduce the temperature. The heat pipe is generally composed of a shell, a liquid absorption core and an end cover, wherein the interior of the heat pipe is pumped into a negative pressure state and filled with a proper amount of liquid with a lower boiling point, and the liquid is easy to volatilize. The liquid absorption core is positioned at the pipe wall and has a capillary structure. One end of the heat pipe is an evaporation end, and the other end is a condensation end. When the evaporation end of the heat pipe is heated, the liquid in the pipe is quickly evaporated, the vapor flows to the condensation end under a slight pressure difference, the vapor is condensed into liquid again when meeting the cold at the condensation end to release heat, and the liquid flows back to the evaporation section along the liquid absorption core, so that the heat can be continuously conducted. In this process, the liquid needs to be refluxed by the capillary suction of the wick capillary structure. The traditional capillary structure is a mesh-woven capillary structure, the capillary suction force of the mesh-woven capillary structure is larger, but the radial heat transfer resistance of the mesh-woven capillary structure is larger, so that a heat pipe with the capillary structure capable of reducing the radial heat transfer resistance is urgently needed.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model provides a heat pipe, the capillary structure of this heat pipe can increase capillary suction when reducing radial heat transfer hindrance, can go out the heat transfer in evaporating zone as early as possible, and the liquid in the shell can flow back smoothly.

The utility model provides a technical scheme that its technical problem adopted is:

the utility model provides a heat pipe, includes shell, evaporation zone and condensation zone, the shell seals and the inside cavity that has, the evaporation zone with the condensation zone is located respectively the both ends of heat pipe, be equipped with a plurality of holes on the inner wall of shell in order to form porous capillary structure, just porous capillary structure's surface still is equipped with woven mesh capillary structure.

As a further improvement of the technical scheme, the porosity range of the porous capillary structure is 20% -60%, the pore diameter range of the pores is 0.01-0.2 mm, and the depth range of the pores is 0.05-0.8 mm.

As a further improvement of the above technical solution, the pore diameter of the pores from the evaporation zone to the condensation zone of the porous capillary structure gradually increases, and the porosity gradually decreases.

As a further improvement of the technical scheme, the capillary structure of the woven mesh at least comprises two groups of woven meshes, the mesh number range of the meshes of the woven meshes is 80-400 meshes, and the pore diameter range of the meshes is 0.04-0.2 mm.

As a further improvement of the above technical solution, a mesh size of the mesh net close to the inner side wall of the housing is larger than a mesh size of the mesh net far from the inner side wall of the housing.

As a further improvement of the technical scheme, the mesh size of the woven net from the evaporation zone to the condensation zone is gradually increased, and the porosity is gradually reduced.

As a further improvement of the above technical solution, a plurality of support columns are further disposed in the cavity, two ends of each support column are respectively fixed to opposite sides of the inner side wall of the housing, and the support columns penetrate through partial meshes of the mesh grid capillary structure.

As a further improvement of the above technical solution, an insulating region is provided between the evaporation region and the condensation region, the outer wall of the housing of the evaporation region is in contact with a heat source, and the outer wall of the housing of the condensation region is provided with heat dissipation fins and a fan.

The utility model has the advantages that: the utility model provides a heat pipe can increase capillary suction when reducing radial heat transfer hindrance, can go out the heat transfer in evaporating zone as early as possible, and the liquid in the shell can flow back smoothly.

Drawings

The invention will be further described with reference to the following figures and examples:

FIG. 1 is a cross-sectional view of a heat pipe (excluding support posts) in a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a heat pipe (excluding support columns) according to a first embodiment of the present invention;

fig. 3 is a schematic structural view of a mesh grid and a support pillar according to a first embodiment of the present invention;

fig. 4 is a schematic cross-sectional view of a heat pipe (excluding the support columns) according to a second embodiment of the present invention.

Detailed Description

The conception, specific structure and technical effects of the present invention will be described clearly and completely with reference to the accompanying drawings and embodiments, so as to fully understand the objects, aspects and effects of the present invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. Furthermore, the description of the upper, lower, left, right, front, rear, etc. used in the present invention is only relative to the mutual position relationship of the components of the present invention in the drawings.

Furthermore, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any combination of one or more of the associated listed items.

It should be noted that the dimensions in the drawings are for the sake of enlargement and do not represent actual dimensions.

Referring to fig. 1 and 2, a cross-sectional view (excluding the support columns) and a cross-sectional view (excluding the support columns) of the heat pipe according to the first embodiment of the present invention are shown. The heat pipe comprises a housing 1 and a capillary structure 2. The shell 1 of the heat pipe is hollow and closed at the end, and a cavity 3 is formed inside the shell. A proper amount of low-melting-point working liquid such as water, ethanol or acetone is placed in the cavity 3.

The heat pipe is provided with an evaporation area 11 and a condensation area 12, the evaporation area 11 and the condensation area 12 are respectively positioned at two end areas of the heat pipe, and the area between the evaporation area 11 and the condensation area 12 is an adiabatic area. The housing at the evaporation zone 11 is in contact with a heat source that causes the working liquid inside the evaporation zone 11 to evaporate into a gas. The gas flows in the cavity 3 to the condensation area 12, and a heat dissipation fin (not shown) is disposed at the housing of the condensation area 12, and a fan is disposed to accelerate the heat transfer in the area. The gas will be liquefied into liquid in the region when meeting cold, and the liquid will flow back to the evaporation area 11 tightly attached to the inner side wall of the housing 1 under the action of the capillary suction force of the capillary structure 2.

The capillary structure 2 is formed by compounding a porous capillary structure 21 and a woven mesh capillary structure 22. The porous capillary structure 21 is integrally formed on the inner side wall of the housing 1, and the mesh-grid capillary structure 22 is attached to the surface of the porous capillary structure 21.

A plurality of minute holes 211 are formed on the inner side wall of the housing 1 by a chemical etching or electrochemical etching method to form the porous capillary structure 21. If the size of the hole 211 is too large, the porosity is too small, and the capillary suction force to the liquid may be insufficient, and if the size of the hole 211 is too small, the porosity is too large, and although the capillary suction force is large, the flow resistance of the liquid is increased accordingly, and therefore, the porosity and the size of the hole need to be in a relatively balanced value range. Typically, the porosity of the porous capillary structure 21 is in the range of 20% to 60%, the pore diameter of the pores 211 is in the range of 0.01mm to 0.2mm, and the depth of the pores 211 is in the range of 0.05mm to 0.8 mm.

The material of the heat pipe can be adjusted according to the parameters of the etching solution or the etching power supply, and usually, copper, aluminum, stainless steel, titanium alloy, and the like can be selected. The parameters of the capillary structure, such as the pore size, the porosity and the like, are selected according to the use requirement, and then the proper concentration of the etching solution and the power supply parameters are selected according to the parameters. The fabrication of holes in a metal surface by etching is well known in the art and will not be described herein.

After the porous capillary structure 21 is formed on the inner side wall of the housing 1, a woven mesh is welded or bonded to the surface of the porous capillary structure 21 to form a composite capillary structure. As shown in fig. 3, a schematic structural diagram of the mesh grid and the support column in the first embodiment of the present invention is shown. A plurality of intersecting wires 221 form the mesh grid 22, with a plurality of mesh openings being present in the mesh grid 22. The braided wire 221 is a metal wire, and usually a copper wire. If the porosity of the mesh openings in the woven mesh is too small and the mesh openings are too large, the capillary suction force for the working fluid may be insufficient, and if the porosity is too large and the mesh openings are too small, the flow resistance of the fluid is increased accordingly, and the porosity and the mesh openings need to be in a relatively balanced numerical range. Typically, the mesh openings have a pore size in the range of 0.04mm to 0.2mm and a mesh size in the range of 80 mesh to 400 mesh.

The capillary structure of the woven mesh can generate larger capillary suction force to working liquid, but the resistance to liquid flow is larger, so that a mode of combining multiple layers of woven meshes can be used. In this embodiment, the mesh-woven capillary structure is composed of at least two sets of mesh-woven meshes, each set of mesh-woven meshes may comprise a single layer or multiple layers. The woven net far away from one side of the inner side wall of the shell 1 selects a fine net with larger porosity and smaller mesh size, and the layers of woven nets close to the inner side wall of the shell 1 select a coarse net with smaller porosity and larger mesh size. The design can make the fine net on the surface provide larger capillary suction force, and the coarse net on the inner side reduces the flow resistance.

In addition, parameters of the woven mesh can be changed along the axial direction of the heat pipe, the mesh size of the woven mesh from the evaporation zone 11 to the condensation zone 12 is gradually increased, and the porosity is gradually reduced. Similarly, the parameters of the porous capillary structure can be changed along the axial direction of the heat pipe. The pore diameter of the pores of the porous capillary structure from the evaporation zone 11 to the condensation zone 12 gradually increases and the porosity gradually decreases. The design is such that the capillary attraction of the capillary structure 2 to the liquid decreases from the evaporation zone 11 to the condensation zone 12. Thus, it is advantageous that the liquid in the condensation zone 12 is refluxed to the evaporation zone 11 as soon as possible.

In addition, support posts may also be placed within the cavity of the heat pipe in order to enhance the support of the wall of the heat pipe. As shown in fig. 3, the supporting column 4 penetrates through part of the meshes of the mesh grid 22, and two ends of the supporting column are respectively fixed on opposite sides of the heat pipe. In order to avoid the support columns 4 blocking the flow channels in the heat pipe, the support columns 4 cannot be arranged too densely, and only partial meshes are placed, and the placement positions are staggered as much as possible.

In the embodiment, the performance of the heat pipe is better by combining the porous capillary structure and the mesh-woven capillary structure. Not only gives consideration to the good capillary suction of the woven mesh, but also obtains the smaller radial thermal resistance of the porous tissue, thereby obtaining better heat transfer capability.

Referring to fig. 4, a schematic cross-sectional view of a heat pipe (excluding support posts) in a second embodiment of the present invention is shown. The present embodiment differs from the first embodiment only in the shape of the casing of the heat pipe. The housing may be shaped as desired, tubular being not the only option.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A heat pipe is characterized by comprising a shell, an evaporation area and a condensation area, wherein the shell is closed and is internally provided with a cavity, the evaporation area and the condensation area are respectively positioned at two ends of the heat pipe, the inner wall of the shell is provided with a plurality of holes to form a porous capillary structure, and the surface of the porous capillary structure is also provided with a woven mesh capillary structure.

2. A heat pipe according to claim 1 wherein the porosity of the porous wick structure is in the range of 20% to 60%, the pore size of the pores is in the range of 0.01mm to 0.2mm, and the depth of the pores is in the range of 0.05mm to 0.8 mm.

3. A heat pipe as claimed in claim 1 wherein said porous wick structure has a pore size that gradually increases and a porosity that gradually decreases from said evaporation zone to said hole of said condensation zone.

4. A heat pipe according to claim 1 wherein said mesh-woven capillary structure comprises at least two sets of mesh-woven meshes, said mesh-woven meshes having mesh openings in the range of 80 mesh to 400 mesh, said mesh openings having pore diameters in the range of 0.04mm to 0.2 mm.

5. A heat pipe as claimed in claim 4 wherein the mesh size of said mesh near the inner side wall of said housing is greater than the mesh size of said mesh remote from the inner side wall of said housing.

6. A heat pipe as claimed in claim 4 wherein the mesh size of said mesh grid increases and the porosity decreases from said evaporation zone to said condensation zone.

7. A heat pipe according to claim 1 wherein a plurality of support posts are further disposed in the cavity, two ends of the support posts are respectively fixed to opposite sides of the inner sidewall of the housing, and the support posts penetrate through partial meshes of the mesh-woven capillary structure.

8. A heat pipe as claimed in claim 1 wherein an adiabatic region is provided between said evaporation region and said condensation region, an outer wall of a housing of said evaporation region is in contact with a heat source, and a heat dissipating fin and a fan are provided at an outer wall of a housing of said condensation region.