CN214250683U

CN214250683U - Heat pipe

Info

Publication number: CN214250683U
Application number: CN202120279425.6U
Authority: CN
Inventors: 王学梅
Original assignee: Yahao Electronic Hardware & Plastic Huizhou Co ltd
Current assignee: Yahao Electronic Hardware & Plastic Huizhou Co ltd
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-09-21
Anticipated expiration: 2031-02-01

Abstract

The utility model discloses a heat pipe, which comprises a pipe body, two end caps and a first capillary core; a plurality of groove structures which are arranged along the axial direction of the pipe body are uniformly distributed on the circumferential direction of the inner wall of the pipe body; the tube body is provided with an evaporation section and a condensation section, and the two end covers are positioned at the two ends of the tube body and used for sealing the tube body; the first capillary core is attached to the groove structure of the evaporation section, and the liquid working medium is evaporated and vaporized in the evaporation section to form steam; the groove structure on the inner wall of the condensation section enables the condensed working medium liquid to flow back to the evaporation section. The utility model solves the contradiction between the capillary force of the heat pipe with a single capillary structure and the reflux resistance of the working medium liquid, and improves the heat transfer power of the heat pipe; the utility model discloses have good process repeatability and reliability, make simply the low price.

Description

Heat pipe

Technical Field

The present invention relates to a heat conducting element, and more particularly to a heat pipe.

Background

The heat pipe is a hollow metal pipe body with two sealed ends, a closed cavity of the heat pipe contains liquid working medium, and the heat pipe is also provided with a capillary structure. The actuating mechanism is that liquid phase working medium absorbs heat in the evaporation section and is vaporized into vapor phase working medium, local high pressure is generated in the closed cavity, the vapor phase working medium is driven to flow to the condensation section at high speed, and the vapor phase working medium flows back to the evaporation section through the capillary structure after being cooled and released heat in the condensation section and is condensed into liquid phase working medium, so that a closed cycle is completed. That is, the heat pipe is circulated by the liquid-gas two-phase change of the liquid working medium in the closed cavity, so that the heat pipe has the characteristic of rapid temperature equalization to achieve the purpose of heat transfer.

The heat pipe has a wide application range, is used in the aerospace field in the early days, is widely used in various heat exchangers, coolers and the like, and is a most commonly used high-efficiency heat-conducting element in the heat dissipation device of electronic products in the present days. Under the harsh conditions of sharply increased heat flux density, increasingly narrow heat dissipation space and the like, the improvement of the heat transfer power of the heat pipe is very slow; under the unchangeable condition of heat pipe geometric dimensions and liquid working medium, the heat transfer power of heat pipe mainly is decided by capillary structure, therefore how to improve and optimize the heat transfer power in order to promote the heat pipe to capillary structure and its arrangement, is the utility model discloses the key problem that will solve.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a promote the heat transfer power of heat pipe, specially provide a heat pipe, wherein, include:

the pipe body is characterized in that a plurality of groove structures are uniformly distributed in the circumferential direction of the inner wall of the pipe body, and the groove structures are arranged along the axial direction of the pipe body and traverse the whole inner wall surface of the pipe body in the length direction; the tube body is provided with an evaporation section and a condensation section;

the two end covers are positioned at two ends of the tube body and used for sealing the tube body;

and the first capillary core is formed by uniformly attaching metal powder to the groove structure of the evaporation section in an equal thickness manner in a sintering manner, and the evaporation section evaporates and vaporizes the liquid working medium to form steam.

In the above heat pipe, the pipe body and the groove structure are integrally formed.

The heat pipe further includes a second capillary wick, wherein the second capillary wick is formed by uniformly adhering metal powder to the groove structure of the condensation section in an equal thickness manner through sintering; the second capillary core is communicated with the first capillary core, and condensed working medium liquid flows back to the evaporation section at the condensation section.

In the above heat pipe, the thickness of the second capillary wick is greater than the thickness of the first capillary wick.

In the above heat pipe, a transmission section is further disposed between the evaporation section and the condensation section; the third capillary core is formed by uniformly attaching metal powder to the groove structure of the transmission section in an equal thickness mode in a sintering mode; and the third capillary core is communicated with the first capillary core, and the condensed working medium liquid is conveyed to the evaporation section in the transmission section.

In the above heat pipe, the thickness of the third capillary wick is greater than the thickness of the first capillary wick.

The heat pipe further includes a fourth wick, wherein the fourth wick is made of metal powder or a metal woven mesh and is attached to the groove structure of the upper half portion of the condensation section in the circumferential direction through sintering, and an exposed surface of the fourth wick located inside the pipe body is a plane; and the fourth capillary core is communicated with the first capillary core, and the condensed working medium liquid flows back to the evaporation section at the condensation section.

In the above heat pipe, the thickness of the fourth wick is greater than the thickness of the first wick.

The heat pipe above, wherein the fourth wick is further attached to the upper half portion of the first wick in the circumferential direction.

In the above heat pipe, a cross-sectional shape of each of the groove structures may be one of a triangle, a rectangle, or a trapezoid.

In the above heat pipe, the cross-sectional shape of the pipe body may be one of a circle, an ellipse, a rectangle, a flat shape and a polygon.

In the above heat pipe, the shape of the pipe body may be one of a uniform cross section or a variable cross section.

In the above heat pipe, the overall shape of the pipe body may be one of a straight pipe type or a bent pipe type.

Compared with the prior art, the utility model has the advantages that: the groove structure arranged on the inner wall of the tube body at the evaporation section of the heat tube can increase the evaporation surface area of the liquid working medium in the capillary core attached to the groove structure, so that the capillary force of the capillary core is larger; made of goldThe capillary core is formed by sintering powder or metal woven mesh and has very small capillary radius r_effThe capillary force of the capillary core is stronger, and simultaneously, because the groove structure has higher permeability K, the reflux resistance of the working medium liquid can be reduced, so that the condensed working medium liquid can quickly reflux to the evaporation section; the utility model solves the contradiction between the capillary force of the heat pipe with a single capillary structure and the reflux resistance of the working medium liquid, and improves the heat transfer power of the heat pipe; the utility model discloses have good process repeatability and reliability, make simply the low price.

The above description of the present invention and the following description of the embodiments are provided to illustrate and explain the principles of the present invention and to provide further explanation of the scope of the present invention.

Drawings

Fig. 1 is a schematic cross-sectional view of a heat pipe according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1;

fig. 4 is a schematic cross-sectional view of a heat pipe according to a second embodiment of the present invention;

FIG. 5 is a cross-sectional view taken along section line 5-5 of FIG. 4;

FIG. 6 is a cross-sectional view taken along section line 6-6 of FIG. 4;

fig. 7 is a schematic cross-sectional view of a heat pipe according to a third embodiment of the present invention;

FIG. 8 is a cross-sectional view taken along section line 8-8 of FIG. 7;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 7;

FIG. 10 is a cross-sectional view taken along section line 11-11 of FIG. 7;

fig. 11 is a schematic cross-sectional view of a heat pipe according to a fourth embodiment of the present invention;

FIG. 12 is a cross-sectional view taken along line 12-12 of FIG. 11;

FIG. 13 is a cross-sectional view taken along section line 13-13 of FIG. 11;

fig. 14 is a schematic cross-sectional view of a heat pipe according to a fifth embodiment of the present invention;

FIG. 15 is a cross-sectional view taken along section line 15-15 of FIG. 14;

FIG. 16 is a cross-sectional view taken along section line 16-16 of FIG. 14.

Wherein, the reference numbers:

10. 10a, 10b, 10c, 10d

100. 100a, 100b, 100c, 100d

101. 101a, 101b, 101c, 101d

110. 110a, 110b, 110c, 110d

120. 120a, 120b, 120c, 120d

130b

200. 200a, 200b, 200c, 200d

300. 300a, 300b, 300c, 300d

400. 400a, 400b, 400c, 400d

A second capillary wick

A third capillary wick

700c, 700d

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention. Additionally, the same or similar numbered elements/components used in the drawings and the embodiments are used to represent the same or similar parts.

With respect to directional terminology used herein, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology used is intended to be illustrative and is not intended to be limiting of the present teachings.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

As used herein, "and/or" includes any and all combinations of the described items.

References to "plurality" herein include "two" and "more than two"; reference to "multiple sets" herein includes "two sets" and "more than two sets".

Certain words used to describe the present application are discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the present application.

The utility model discloses a based on heat pipe heat transfer power's rationale, improve and optimize the structure of heat pipe to realize heat pipe heat transfer power's promotion.

Q for maximum heat transfer power of heat pipe_maxExpressed, the theoretical calculation can be made from the following equation:

in the above formula, the first and second light sources are,

representing the fluid properties of the liquid working substance; wherein ρ: liquid density, h_fg: latent heat of evaporation, σ: surface tension, μ: liquid viscosity coefficient;

represents the geometry of the heat pipe; wherein A is_w: cross sectional area of heat pipe, L_eff: the effective length of the heat pipe;

represents the nature of the capillary structure; wherein, K: permeability, r_eff: capillary radius, θ_e: the contact angle.

According to the formula, under the condition that the geometric size of the heat pipe and the liquid working medium are not changed, the heat transfer power of the heat pipe is mainly determined by the capillary structure; the larger the permeability K, the larger the capillary radius r_effThe smaller the value, the maximum heat transfer power Q of the heat pipe_maxThe higher. Therefore, the utility model discloses mainly follow permeability K value and capillary radius r_effThe study was started on the values.

The commonly used capillary structures mainly include a groove type, a sintering type, a woven mesh type and the like. In the selection of the capillary structure, the capillary structure should have a very small capillary radius r from the viewpoint of the requirement to provide maximum heat transfer power_effSo that it has a sufficiently large capillary force and at the same time should have a high permeability K to reduce the flow resistance of the returning liquid.

A single type of capillary structure often fails to compromise both capillary force and permeability. The groove type capillary structure generates capillary force by utilizing the radius change of a working medium liquid meniscus in the groove, the capillary force is small but has high permeability K and low liquid reflux resistance, and high axial heat transfer capacity can be achieved; sintered and woven mesh type capillary structures having a capillary radius r_effThe capillary force is small, so that the capillary force is large, the heat transfer quantity is large, but the permeability K value is low, the liquid backflow resistance is large, and the capillary force is improved and the liquid backflow resistance is increased.

Therefore the utility model discloses a can compromise the heat pipe of combined type capillary structure of capillary force and permeability very much, aim at obtaining the heat transfer power of great capillary force and higher axial heat transfer ability in order to promote the heat pipe. The heat pipe basically divides the capillary structure into two parts, one part of the capillary structure is used for pumping, and the groove structure is used for providing a return channel of the liquid working medium in the heat pipe, so that the heat transfer power of the heat pipe is improved while the return resistance of the liquid working medium in the heat pipe is reduced.

The first embodiment is as follows:

please refer to fig. 1 to 3. Fig. 1 is a schematic cross-sectional view of a heat pipe according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1; FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1. As shown in fig. 1 to 3, the heat pipe 10 of the present invention includes a pipe body 100, an evaporation section end cap 200, a condensation section end cap 300, and a first capillary wick 400; a plurality of groove structures 101 are uniformly distributed on the inner wall of the tube body 100 in the axial direction, the groove structures 101 are arranged along the axial direction of the tube body 100 and traverse the whole inner wall surface of the tube body 100 in the length direction, and the tube body 100 and the groove structures 101 are integrally formed; the tube 100 is provided with an evaporation section 110 and a condensation section 120; two end caps, i.e., an evaporation end cap 200 and a condensation end cap 300, respectively located at two ends of the tube 100 for sealing the tube 100; a first capillary core 400, which is formed by uniformly attaching metal powder to the groove structure 101 of the evaporation section 110 in an equal thickness manner by high-temperature sintering, and evaporating and vaporizing the liquid working medium in the evaporation section 110 to form vapor; the groove structure 101 of the condensing section 120 returns the condensed working fluid to the evaporating section 110 at the condensing section 120.

The direction of the dashed arrow in fig. 1 is the flow direction of the working medium vapor, and the working process of the heat pipe 10 is specifically described below with reference to fig. 1. After absorbing heat from a heat source, the evaporation section 110 vaporizes the liquid working medium into steam to generate local high pressure, the steam flows to the condensation section 120 along the central channel under the action of pressure, when the steam is condensed into liquid in the condensation section 120, the steam releases vaporization potential energy, so that the heat is transferred to the condensation section 120, and the condensed working medium liquid flows back to the evaporation section 110 through the groove structure 101 of the condensation section 120. After such a cycle, the heat absorbed by the evaporation section 110 from the heat source is continuously transferred to the condensation section 120, so that the heat pipe 10 exhibits the characteristic of rapid temperature equalization to achieve the purpose of heat transfer.

In this embodiment, the first capillary wick 400 is combined on the groove structure 101 of the evaporation section 110, the groove structure 101 increases the evaporation surface area of the liquid working medium infiltrated into the first capillary wick 400, so that the capillary force of the first capillary wick 400 can be increased, and the first capillary wick 400 formed by sintering metal powder has a very small capillary radius r_effSo that the capillary force is stronger; meanwhile, because the groove structure 101 has higher permeability K, the reflux resistance of the working medium liquid can be reduced, and the condensed working medium liquid can quickly reflux to the whole evaporation section 110; in the first embodiment, the condensing section 120 adopts the groove structure 101, and the permeability K value of the groove structure 101 is large, so that the reflux speed of the working medium liquid is high; therefore, the present embodiment enables the maximum heat transfer power Q of the heat pipe 10_maxIs lifted.

In the first embodiment, because the condensing section 120 only adopts the groove structure 101, the condensed working medium liquid can better flow back to the evaporating section 110 under the action of gravity, and is more suitable for the working state of the heat pipe 10 with the condensing section 120 above, that is, when the heat pipe 10 is in the antigravity working state with the evaporating section 110 above, the advantage of the flow back speed can not be fully exerted; however, the embodiment is very suitable for the zero gravity condition of the space and is widely applied to the space aircraft.

Example two:

please refer to fig. 4 to 6. Fig. 4 is a schematic cross-sectional view of a heat pipe according to a second embodiment of the present invention; FIG. 5 is a cross-sectional view taken along section line 5-5 of FIG. 4; FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 4. As shown in fig. 4 to fig. 6, the heat pipe 10a of the present invention includes a pipe body 100a, an evaporation section end cap 200a, a condensation section end cap 300a, a first capillary wick 400a, and a second capillary wick 500 a; a plurality of groove structures 101a are uniformly distributed on the inner wall of the tube body 100a in the axial direction, the groove structures 101a are arranged along the axial direction of the tube body 100a and traverse the whole inner wall surface of the tube body 100a in the length direction, and the tube body 100a and the groove structures 101a are integrally formed; the tube 100a is provided with an evaporation section 110a and a condensation section 120 a; two end caps, i.e., an evaporation end cap 200a and a condensation end cap 300a, respectively located at two ends of the tube 100a for sealing the tube 100 a; the first capillary core 400a is formed by uniformly attaching metal powder to the groove structure 101a of the evaporation section 110a in an equal thickness manner through high-temperature sintering, and evaporating and vaporizing the liquid working medium in the evaporation section 110a to form steam; the second capillary wick 500a is formed by uniformly attaching metal powder to the groove structure 101a of the condensation section 120a in an equal thickness manner through high-temperature sintering, the second capillary wick 500a is communicated with the first capillary wick 400a, and the condensed working medium liquid flows back to the evaporation section 110a in the condensation section 120 a; the thickness of the second capillary wick 500a is greater than the thickness of the first capillary wick 400 a.

The direction of the dashed arrow in fig. 4 is the flow direction of the working medium vapor, and the working process of the heat pipe 10a will be described in detail below with reference to fig. 4. After absorbing heat from the heat source, the evaporation section 110a vaporizes the liquid working medium into steam to generate local high pressure, the steam flows to the condensation section 120a along the central channel under the action of the pressure, when the steam is condensed into liquid in the condensation section 120a, the steam releases vaporization potential energy, so that the heat is transferred to the condensation section 120a, and the condensed working medium liquid flows back to the evaporation section 110a through the second capillary wick 500a and the groove structure 101 a. After such a cycle, the heat absorbed by the evaporation section 110a from the heat source is continuously transferred to the condensation section 120a, so that the heat pipe 10a exhibits a rapid temperature equalization characteristic to achieve the purpose of heat transfer.

In the second embodiment, the first capillary wick 400a is combined on the groove structure 101a of the evaporation section 110a, the groove structure 101a increases the evaporation surface area of the liquid working medium infiltrated into the first capillary wick 400a, so that the capillary force of the first capillary wick 400a is larger, and the first capillary wick 400a formed by sintering metal powder has a very small capillary radius r_effSo that the capillary force is stronger; meanwhile, because the groove structure 101a has higher permeability K, the resistance of the working medium liquid to flow back is reduced, and the working medium liquid can quickly flow back to the whole evaporation section 110 a; in the second embodiment, the second capillary wick 500a is composited on the groove structure 101a of the condensation section 120a, both the groove structure 101a and the second capillary wick 500a are used as channels for the backflow of the working medium liquid, and the permeability K of the groove structure 101a is large, so that the backflow speed of the working medium liquid is high; therefore, the maximum heat transfer power Q of the heat pipe 10a is obtained in the second embodiment_maxIs lifted.

In the second embodiment, because the second capillary wick 500a is compounded on the groove structure 101a of the condensation section 120a, even when the heat pipe 10a is in the anti-gravity working state with the evaporation section 110a on top, because the thickness of the second capillary wick 500a is greater than that of the first capillary wick 400a, the return speed of the working medium liquid in the condensation section 120a of the heat pipe 10a is increased, and the evaporation speed of the evaporation section 110a of the heat pipe 10a is increased accordingly, so that the return speed and the heat transfer capability of the heat pipe 10a are considered at the same time. The second embodiment is more advantageous when the heat pipe 10a is in the anti-gravity working state with the evaporation section 110a on top.

Example three:

please refer to fig. 7 to 10. Fig. 7 is a schematic cross-sectional view of a heat pipe according to a third embodiment of the present invention; FIG. 8 is a cross-sectional view taken along section line 8-8 of FIG. 7; FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 7; FIG. 10 is a cross-sectional view taken along section line 11-11 of FIG. 7. As shown in fig. 7 to 10, the heat pipe 10b of the present invention includes a pipe body 100b, an evaporation end cap 200b, a condensation end cap 300b, a first capillary wick 400b, and a third capillary wick 600 b; a plurality of groove structures 101b are uniformly distributed on the inner wall of the tube body 100b in the axial direction, the groove structures 101b are arranged along the axial direction of the tube body 100b and traverse the whole inner wall surface of the tube body 100b in the length direction, and the tube body 100b and the groove structures 101b are integrally formed; the evaporation section 110b, the transmission section 130b and the condensation section 120b are sequentially arranged on the tube body 100 b; two end caps, i.e., an evaporation end cap 200b and a condensation end cap 300b, respectively located at two ends of the tube 100b for sealing the tube 100 b; the first capillary core 400b is formed by uniformly attaching metal powder to the groove structure 101b of the evaporation section 110b in an equal thickness manner through high-temperature sintering, and the evaporation section 110b evaporates and vaporizes the liquid working medium to form steam; the third capillary wick 600b is formed by uniformly attaching metal powder to the groove structure 101b of the transmission section 130b in an equal thickness manner through high-temperature sintering, the third capillary wick 600b is communicated with the first capillary wick 400b, and the condensed working medium liquid is conveyed to the evaporation section 110b in the transmission section 130 b; the groove structure 101b of the condensing section 120b returns the condensed working medium liquid to the evaporating section 110b through the transmission section 130b in the condensing section 120 b; the thickness of the third capillary wick 600b is greater than the thickness of the first capillary wick 400 b.

The direction of the dashed arrow in fig. 7 is the flow direction of the working medium vapor, and the working process of the heat pipe 10b is specifically described below with reference to fig. 7. After absorbing heat from a heat source, the evaporation section 110b vaporizes the liquid working medium into steam to generate local high pressure, the steam flows to the condensation section 120b through the transmission section 130b along the central channel under the action of the pressure, when the steam is condensed into liquid in the condensation section 120b, the steam releases vaporization potential energy, so that the heat is transferred to the condensation section 120b, and the condensed working medium liquid flows back to the evaporation section 110b through the groove structure 101b and the third capillary core 600b. After such a cycle, the heat absorbed by the evaporation section 110b from the heat source is continuously transferred to the condensation section 120b, so that the heat pipe 10b exhibits a rapid temperature equalization characteristic to achieve the purpose of heat transfer.

In the third embodiment, the first capillary wick 400b is combined on the groove structure 101b of the evaporation section 110b, the groove structure 101b increases the evaporation surface area of the liquid working medium infiltrated into the first capillary wick 400b, so that the capillary force of the first capillary wick 400b can be larger, and the first capillary wick 400b formed by sintering metal powder has a very small capillary radius r_effSo that the capillary force is stronger; meanwhile, because the groove structure 101b has higher permeability K, the resistance of the working medium liquid to flow back is reduced, and the working medium liquid can quickly flow back to the whole evaporation section 110 b; in the third embodiment, the third capillary wick 600b is composited on the groove structure 101b of the transmission section 130b, the groove structure 101b is adopted in the condensation section 120b, both the groove structure 101b and the third capillary wick 600b are used as channels for the backflow of the working medium liquid, and the permeability K value of the groove structure 101b is large, so that the backflow speed of the working medium liquid is high; therefore, the third embodiment enables the maximum heat transfer power Q of the heat pipe 10b_maxIs lifted.

In the third embodiment, because only the groove structure 101b is adopted in the condensation section 120b, the condensed working medium liquid can better flow back to the evaporation section 110b through the groove structure 101b and the third capillary wick 600b under the action of gravity, and is more suitable for the working state that the heat pipe 10b is positioned above the condensation section 120b, that is, the advantage of the return speed of the heat pipe 10b cannot be fully exerted when the heat pipe 10b is positioned in the anti-gravity working state that the evaporation section 110b is positioned above the evaporation section; but the third embodiment is very suitable for the zero gravity condition of the space and is widely applied to the space aircraft. Because the thickness of the third capillary wick 600b is greater than that of the first capillary wick 400b, the return speed of the working medium liquid in the condensation section 120b of the heat pipe 10b is increased, and the evaporation speed of the evaporation section 110b of the heat pipe 10b is increased accordingly, so that the return speed and the heat transfer capacity of the heat pipe 10b are considered.

Example four:

please refer to fig. 11 to 13. Fig. 11 is a schematic cross-sectional view of a heat pipe according to a fourth embodiment of the present invention; FIG. 12 is a cross-sectional view taken along line 12-12 of FIG. 11; FIG. 13 is a cross-sectional view taken along section line 13-13 of FIG. 11. As shown in fig. 11 to 13, the heat pipe 10c of the present invention includes a pipe body 100c, an evaporation section end cover 110c, a condensation section end cover 120c, a first capillary wick 400c, and a fourth capillary wick 700 c; a plurality of groove structures 101c are uniformly distributed on the inner wall of the tube body 100c in the axial direction, the groove structures 101c are arranged along the axial direction of the tube body 100c and traverse the whole inner wall surface of the tube body 100c in the length direction, and the tube body 100c and the groove structures 101c are integrally formed; the tube 100c is provided with an evaporation section 110c and a condensation section 120 c; two end caps, i.e., an evaporation end cap 200c and a condensation end cap 300c, respectively located at two ends of the tube 100c to seal the tube 100 c; the first capillary core 400c is formed by uniformly attaching metal powder to the groove structure 101c of the evaporation section 110c in an equal thickness manner through high-temperature sintering, and evaporating and vaporizing the liquid working medium in the evaporation section 110c to form steam; a fourth capillary core 700c, which is made of metal powder or a metal mesh grid, and is attached to the groove structure 101c at the upper half part of the condensation section 120c in the circumferential direction by means of high-temperature sintering, and an exposed surface of the fourth capillary core located inside the tube body 100c is a plane; the fourth capillary core 700c is communicated with the first capillary core 400c, and the condensed working medium liquid flows back to the evaporation section 110 c; the thickness of the fourth capillary wick 700c is greater than the thickness of the first capillary wick 400 c.

The direction of the dashed arrow in fig. 11 is the flow direction of the working medium vapor, and the working process of the heat pipe 10c will be specifically described below with reference to fig. 11. After absorbing heat from a heat source, the evaporation section 110c vaporizes the liquid working medium into steam to generate local high pressure, the steam flows to the condensation section 120c along the central channel under the action of the pressure, when the steam is condensed into liquid in the condensation section 120c, the steam releases vaporization potential energy, so that the heat is transferred to the condensation section 120c, and the condensed working medium liquid flows back to the evaporation section 110c through the fourth capillary core 700c and the groove structure 101 c. After such a cycle, the heat absorbed by the evaporation section 110c from the heat source is continuously transferred to the condensation section 120c, so that the heat pipe 10c exhibits a rapid temperature equalization characteristic to achieve the purpose of heat transfer.

In this embodiment, the first capillary wick 400c is combined on the groove structure 101c of the evaporation section 110c, the groove structure 101c increases the evaporation surface area of the liquid working medium infiltrated into the first capillary wick 400c, so that the capillary force of the first capillary wick 400c can be increased, and the first capillary wick 400c formed by sintering metal powder has a very small capillary radius r_effSo that the capillary force is stronger; meanwhile, because the groove structure 101c has higher permeability K, the resistance of the working medium liquid to flow back is reduced, and the working medium liquid can quickly flow back to the whole evaporation section 110 c; in the fourth embodiment, the fourth capillary core 700c is composited on the groove structure 101c of the condensation section 120c, both the groove structure 101c and the fourth capillary core 700c are used as channels for working medium liquid to flow back, and the permeability K of the groove structure 101c is large, so that the working medium liquid flow back speed is high; therefore, the present embodiment enables the maximum heat transfer power Q of the heat pipe 10c_maxIs lifted.

In the fourth embodiment, because the fourth capillary wick 700c is combined on the groove structure 101c of the condensation section 120c, even when the heat pipe 10c is in the antigravity working state with the evaporation section 110c on top, because the thickness of the fourth capillary wick 700c is greater than that of the first capillary wick 400c, the return speed of the working medium liquid in the condensation section 120c of the heat pipe 10c is increased, and the evaporation speed of the evaporation section 110c of the heat pipe 10c is increased accordingly, so that the return speed and the heat transfer capability of the heat pipe 10c are considered at the same time. This fourth embodiment is further advantageous when the heat pipe 10c is in the anti-gravity operating state with the evaporation section 110c on top.

Example five:

please refer to fig. 14 to 16. Fig. 14 is a schematic cross-sectional view of a heat pipe according to a fifth embodiment of the present invention; FIG. 15 is a cross-sectional view taken along section line 15-15 of FIG. 14; FIG. 16 is a cross-sectional view taken along section line 16-16 of FIG. 14. As shown in fig. 14 to 16, the heat pipe 10d of the present invention includes a pipe body 100d, an evaporation end cap 200d, a condensation end cap 300d, a first capillary wick 400d, and a fourth capillary wick 700 d; a plurality of groove structures 101d are uniformly distributed on the inner wall of the tube body 100d in the axial direction, the groove structures 101d are arranged along the axial direction of the tube body 100d and traverse the whole inner wall surface of the tube body 100d in the length direction, and the tube body 100d and the groove structures 101d are integrally formed; the tube 100d is provided with an evaporation section 110d and a condensation section 120 d; two end caps, namely an evaporation end cap 200d and a condensation end cap 300d, are respectively positioned at two ends of the tube body 100d to seal the tube body 100 d; the first capillary core 400d is formed by uniformly attaching metal powder to the groove structure 101d of the evaporation section 110d in an equal thickness manner through high-temperature sintering, and evaporating and vaporizing the liquid working medium in the evaporation section 110d to form steam; a fourth capillary core 700d, which is made of metal powder or a metal mesh grid, and is attached to the groove structure 101d at the upper half part of the condensation section 120d in the circumferential direction through sintering, and an exposed surface of the fourth capillary core located inside the tube body 100d is a plane; the fourth capillary core 700d is communicated with the first capillary core 400d, and the condensed working medium liquid flows back to the evaporation section 110 d; the thickness of the fourth capillary wick 700d is greater than the thickness of the first capillary wick 400d, and the fourth capillary wick 700d also adheres to the upper half of the first capillary wick 400d in the circumferential direction.

The direction of the dashed arrow in fig. 14 is the flow direction of the working medium vapor, and the operation of the heat pipe 10d will be described in detail with reference to fig. 14. After absorbing heat from the heat source, the evaporation section 110d vaporizes the liquid working medium into steam to generate local high pressure, the steam flows to the condensation section 120d along the central channel under the action of the pressure, when the steam is condensed into liquid in the condensation section 120d, the steam releases vaporization potential energy, so that the heat is transferred to the condensation section 120d, and the condensed working medium liquid flows back to the evaporation section 110d through the fourth capillary core 700d and the groove structure 101d. After such circulation, the heat absorbed by the evaporation section 110d from the heat source is continuously transferred to the condensation section 120d, so that the heat pipe 10d exhibits the characteristic of rapid temperature equalization to achieve the purpose of heat transfer.

In this embodiment, the first capillary wick 400d is combined on the groove structure 101d of the evaporation section 110d, and meanwhile, the first capillary wick 400d is also combinedThe fourth capillary wick 700d is attached to the upper half part, the groove structure 101d increases the evaporation surface area of the liquid working medium infiltrated into the first capillary wick 400d and the fourth capillary wick 700d of the evaporation section 110d, so that the capillary force of the first capillary wick 400d and the fourth capillary wick 700d of the evaporation section 110d can be increased, and the first capillary wick 400d and the fourth capillary wick 700d formed by sintering metal powder have very small capillary radius r_effSo that the capillary force is stronger; meanwhile, because the groove structure 101d has higher permeability K, the resistance of the working medium liquid to flow back is reduced, and the working medium liquid can quickly flow back to the whole evaporation section 110 d; in this embodiment, the fourth capillary core 700d is composited on the groove structure 101d of the condensing section 120d, both the groove structure 101d and the fourth capillary core 700d of the condensing section 120d serve as channels for the working medium liquid to flow back, and the permeability K value of the groove structure 101d is large, so that the working medium liquid flows back quickly; therefore, the maximum heat transfer power Q of the heat pipe 10d is set in this embodiment_maxIs lifted.

In this embodiment, the fourth capillary wick 700d is combined on the groove structure 101d of the condensation section 120 d; even if the heat pipe 10d is in the antigravity working state with the evaporation section 110d above, because the thickness of the fourth capillary wick 700d is greater than the thickness of the first capillary wick 400d, the return speed of the working medium liquid at the condensation section 120d of the heat pipe 10d will be increased, and the evaporation speed of the evaporation section 110d of the heat pipe 10d will be increased accordingly, so as to take account of the return speed and the heat transfer capability of the heat pipe 10d. This fifth embodiment is more advantageous when the heat pipe 10d is in the anti-gravity operating state with the evaporation section 110d on top.

In the above embodiments, it should be noted that:

(1) in the first to fifth embodiments, the heat pipe body is made of a heat conductive material, such as copper, aluminum, carbon steel, stainless steel, alloy copper, gold, silver, or the like; the liquid working medium is a heat transfer medium, can be water, acetone, ammonia and the like, and is selected according to different heat transfer requirements. The evaporation section of the tube is used for being thermally coupled to a heat source (not shown), such as a central processing unit (cpu) or a display card processor, to absorb heat generated by the heat source; the condensation section of the tube is thermally coupled to a heat sink (not shown) to dissipate heat generated by the heat source through the heat sink.

(2) In the second, fourth and fifth embodiments, because the capillary cores are arranged on the respective condensation sections, and the thickness of the capillary core of the condensation section is larger than that of the capillary core of the evaporation section, when the heat pipe is in the antigravity working state with the evaporation section on the upper part, the reflux speed of the working medium liquid of the condensation section is increased, the evaporation speed of the evaporation section is accelerated accordingly, and the reflux speed and the heat transfer capacity of the heat pipe can be taken into consideration, so that the antigravity performance of the second, fourth and fifth embodiments is better; the condensation sections of the first embodiment and the third embodiment only adopt a groove structure, and are more suitable for the working state of the heat pipe with the condensation section above and the zero gravity condition of the space. The permeability K value of the groove structure is large, and when the length of a condensation area of the heat pipe is below 200mm, the reflux speed is high; if the length of the condensation area of the heat pipe exceeds 200mm, the reflux problem will occur only by adopting the groove structure in the condensation area, and at this time, other capillary core structures, including but not limited to the structures shown in embodiments two, four, and five, need to be compounded outside the groove structure of the condensation area, so as to improve the reflux speed of the condensed working medium liquid.

(3) In the first to fifth embodiments, the cross-sectional shape of the heat pipe body is a circle, but the present invention is not limited thereto, and in other embodiments, the cross-sectional shape of the heat pipe body may be one of an ellipse, a rectangle, a flat shape or a polygon.

(4) In the first to fifth embodiments, the outer shape of the heat pipe body is a uniform cross section, but the present invention is not limited thereto, and in other embodiments, the outer shape of the heat pipe body may be one of a variable cross section or a corrugated pipe.

(5) In the first to fifth embodiments, the overall shape of the heat pipe body is a straight pipe type, that is, the evaporation section, the transmission section and the condensation section are arranged in parallel; however, the present invention is not limited thereto, and in other embodiments, the overall shape of the heat pipe body may be a bent pipe type, that is, the evaporation section, the transmission section and the condensation section may not be parallel to each other.

(6) In the first to the fifth embodiments, the cross-sectional shape of the trench structure is a triangle, but the present invention is not limited thereto, and in other embodiments, the designer may design and optimize the cross-sectional shape of the trench structure according to actual needs, and the cross-sectional shape may also be one of a rectangle or a trapezoid.

(7) In the first to fifth embodiments, the structure of the capillary wick is preferably made of copper.

To sum up, the heat pipe structure provided by the present invention has the groove structure formed on the inner wall of the evaporation section pipe body, so that the evaporation surface area of the liquid working medium in the capillary core attached to the groove structure can be increased, and the capillary force of the capillary core is increased; capillary wick sintered from metal powder or metal mesh grid, having very small capillary radius r_effThe capillary force of the capillary core is stronger, and simultaneously, because the groove structure has higher permeability K, the reflux resistance of the working medium liquid can be reduced, so that the condensed working medium liquid can quickly reflux to the evaporation section; the utility model solves the contradiction between the capillary force of the heat pipe with a single capillary structure and the reflux resistance of the working medium liquid, and improves the heat transfer power of the heat pipe; the utility model discloses have good process repeatability and reliability, make simply the low price.

Although the present invention has been described with reference to the above embodiments, it should be understood that the scope of the present invention is not limited to the above embodiments, and other changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. A heat pipe, comprising:

2. A heat pipe as claimed in claim 1 wherein said body is integrally formed with said channel structure.

3. A heat pipe as claimed in claim 1 or 2, further comprising a second wick formed by sintering a metal powder to uniformly adhere the metal powder to the groove structure of the condensation section; the second capillary core is communicated with the first capillary core, and condensed working medium liquid flows back to the evaporation section at the condensation section.

4. A heat pipe as claimed in claim 3, wherein said second wick has a thickness greater than a thickness of said first wick.

5. A heat pipe as claimed in claim 1 or 2 wherein a transport section is provided between said evaporator section and said condenser section; the third capillary core is formed by uniformly attaching metal powder to the groove structure of the transmission section in an equal thickness mode in a sintering mode; and the third capillary core is communicated with the first capillary core, and the condensed working medium liquid is conveyed to the evaporation section in the transmission section.

6. A heat pipe as claimed in claim 5, wherein said third wick has a thickness greater than a thickness of said first wick.

7. A heat pipe as claimed in claim 1 or 2, further comprising a fourth wick formed by sintering a metal powder or a metal mesh net attached to the groove structure of the upper half portion of the condensation section in the circumferential direction, wherein an exposed surface of the fourth wick located inside the pipe body is a flat surface; and the fourth capillary core is communicated with the first capillary core, and the condensed working medium liquid flows back to the evaporation section at the condensation section.

8. A heat pipe as claimed in claim 7, wherein said fourth wick has a thickness greater than a thickness of said first wick.

9. A heat pipe as claimed in claim 8, wherein said fourth wick is further attached circumferentially to an upper half of said first wick.

10. A heat pipe as claimed in claim 1 or 2 wherein each of said channel structures has a cross-sectional shape which is one of triangular, rectangular or trapezoidal.

11. A heat pipe as claimed in claim 1 or 2 wherein said tubular body has a cross-sectional shape which is one of circular, oval, rectangular, flat or polygonal.

12. A heat pipe as claimed in claim 1 or 2 wherein said body is profiled to provide one of a constant cross-section and a variable cross-section.

13. A heat pipe as claimed in claim 1 or 2 wherein the overall shape of said body is one of a straight pipe type or a bent pipe type.