TW201423021A - Heat pipe and method of manufacturing the same - Google Patents

Abstract

A method for manufacturing a heat pipe, includes following steps: (1) providing a tube with a wick structure configured on an inner surface thereof, the tube defining a chamber therein, and the tube including an evaporating section and a condensing section insulated from each other; (2) injecting a working media into the tube, vacuumizing and sealing the tube; (3) defining at least one through hole respectively on the evaporating section and the condensing section; (4) providing at least one metal pipe to communicate the through hole of the evaporating section with that of the condensing section, thereby defining a steam channel.

Description

Heat pipe and manufacturing method thereof

The present invention relates to a heat pipe and a method of manufacturing the same.

At this stage, heat pipes have been widely used for heat dissipation of electronic components with large heat generation. When the heat pipe works, the principle is that the low-boiling working fluid filled inside the pipe body absorbs the heat generated by the heat-generating electronic component in the evaporation section, and then evaporates and vaporizes, and then carries the heat to move through the steam passage to the condensation section, and liquefies in the condensation section. The condensation releases the heat, and the liquefied working fluid is returned to the evaporation section under the action of the capillary structure of the heat pipe wall, and the heat transfer effect is achieved by the circulation motion of the working fluid, thereby generating heat of the electronic component. The heat sink that is quickly transferred to the condensation section of the heat pipe is then emitted.

In a conventional heat pipe, the steam passage and the capillary structure are in contact with each other, and the steam flows forward in the steam passage, and the working fluid flows countercurrently in the capillary structure, and the two interact with each other to produce a shear at the interface between the steam passage and the capillary structure. Shear stress affects the heat transfer performance of the heat pipe.

In view of this, it is necessary to provide a heat pipe that improves the heat transfer performance of the heat pipe and a method of manufacturing the same.

A heat pipe comprises a hollow and sealed end pipe body, the inner wall of the pipe body is provided with a capillary structure, and a cavity is arranged in the pipe body, the working body is provided with a working fluid, and the pipe body comprises an evaporation section and a condensation section The evaporation section and the condensation section are isolated from each other, and the capillary structure extends from the evaporation section to the condensation section along the inner wall of the tube to form a liquid working fluid passage, and the evaporation section and the condensation section are each provided with at least one through hole, and the at least one through hole At least one vapor passage is formed by at least one hollow metal tube being connected in series.

A heat pipe manufacturing method comprising the steps of: providing a pipe body having a capillary structure on an inner wall thereof, wherein a cavity is formed in the pipe body, the pipe body comprises an evaporation section and a condensation section; and the evaporation section is isolated And the condensation section, and only the capillary structure extends from the evaporation section to the condensation section along the inner wall of the pipe to form a liquid working fluid passage; respectively, vacuuming, injecting and sealing the evaporation section and the condensation section of the pipe body; At least one through hole is formed in each of the evaporation section and the condensation section of the pipe body; at least one metal pipe is connected in series to at least one through hole corresponding to the evaporation section and the condensation section, so that at least one steam passage is formed.

The invention provides a through hole in each of the evaporation section and the condensation section of the heat pipe, and the corresponding through holes are connected in series by a hollow metal pipe, and the evaporation section and the cavity of the condensation section are separated by a metal layer. In this way, the steam generated by the evaporation of the working fluid of the evaporation section flows to the condensation section through the steam passage formed by the metal tube, and after the condensation section is cooled, it is gradually condensed into a working fluid, and finally by the tube. The capillary structure of the inner wall is returned to the evaporation section, thus forming a one-way loop, which avoids shear stress when the steam and the working fluid flow relative to each other, thereby improving the heat transfer performance of the heat pipe.

As shown in Figure 1, a heat pipe 1 is provided in accordance with a preferred embodiment of the present invention. The heat pipe 1 includes a hollow pipe body 10. The tube body 10 is sealed at both ends, and a capillary structure 11 is attached to the inner wall thereof. A cavity 12 is disposed in the tube body 10, and a working fluid is disposed in the cavity 12. The tubular body 10 is symmetrical along its central axis. The tube body 10 has a constricted portion 13 along the middle in the longitudinal direction thereof, and the constricted portion 13 partitions the left and right sides of the tube body 10 into the evaporation section 14 and the condensation section 15, and the length of the evaporation section 14 is smaller than the length of the condensation section 15. The inner and outer diameters of the evaporation section 14 are equal to the inner and outer diameters of the condensation section 15, respectively. The constricted portion 13 has a central portion 131 and two end portions 132 on the left and right sides of the central portion 131. The outer diameter and the inner diameter of the central portion 131 are constant, and are smaller than the inner and outer diameters of the evaporation portion 14, respectively, and the outer ends of the outer portions 132 are respectively Both the diameter and the inner diameter gradually increase in a direction away from the central portion 131 until they are equal to the outer diameter and the inner diameter of the evaporation section 14, respectively. A metal layer 16 is also provided in the inner wall of the shrink tube portion 13 and the evaporation portion 14 in the tube body 10. The metal layer 16 is symmetrical about the central axis of the tube body 10. The metal layer 16 has a left end 161 that tapers to the condensing section 15 until it is closed and a right end 162 that is connected to the right side of the left end 161. In the present embodiment, the left end 161 of the metal layer 16 has a hollow conical shape, and the right side of the left end 161 abuts the capillary structure 11 in the end portion 132 on the right side of the constricted portion 13, and the right end 162 of the metal layer 16 and the evaporation section 14 The inner capillary structure 11 is in close contact so that the metal layer 16 isolates the left and right portions of the cavity 12 of the tubular body 10, and the capillary structure 11 extends along the inner wall of the tubular body 10 from the evaporation section 14 to the condensation section 15 to form a liquid operation. Fluid channel. The evaporation section 14 and the condensation section 15 of the pipe body 10 are respectively provided with two through holes 17, and the four through holes 17 are connected in series by two hollow metal pipes 18, that is, the evaporation section 14 and the condensation section 15 of the pipe body 10 are borrowed. Two metal tubes 18 are connected in series to form two steam passages 181.

When the heat pipe 1 is in operation, the evaporation section 14 is in thermal contact with the heat-generating electronic component (not shown), and the working fluid therein is evaporated by heat, generating a pressure on the metal layer 16, since the left end 161 of the metal layer 16 is tapered toward the condensation section 15. Until the closure, the steam is prevented from moving to the condensation section 15, so that the steam flows to the condensation section by the two steam passages 181, and the steam is gradually condensed into a working fluid by the two steam passages 181, and finally flows into the condensation section 15 At this time, the pressure in the cavity 12 is reduced. The working fluid is again returned to the evaporation section 14 by the capillary structure 11 of the inner wall of the pipe body 10, thus forming a unidirectional loop, which avoids shear stress when the steam and the working fluid flow relative to each other, thereby improving the heat transfer performance of the heat pipe. .

It can be understood that the present invention can also isolate the evaporation section 14 of the heat pipe 1 and the cavity of the condensation section 15 by other means, and is not limited to the structure of the metal layer 16 in the embodiment to achieve the purpose.

The method of manufacturing the heat pipe 1 will be described in detail below with reference to FIGS. 2 to 7.

Referring to Fig. 2, a tubular body 20 is provided which is open at both ends. The inner wall of the tubular body 20 is provided with a capillary structure 21, and a cavity 22 is formed therein. In the present embodiment, the tubular body 20 is made of a metal material having good thermal conductivity, such as copper or the like, and has a circular cross section and a central axis. The capillary structure 21 may be a grooved capillary structure formed by providing a plurality of small axial grooves directly on the inner surface of the pipe body 20, a wire mesh capillary structure formed by braiding a metal copper mesh or a fiber bundle, or ceramic powder or A metal powder such as copper powder or the like is formed into a sintered capillary structure through a sintering process.

Referring to FIG. 3, an annular metal layer 30 is embedded and positioned in the cavity 22 of the tubular body 20, and the metal layer 30 is in close contact with the capillary structure 21 in the tubular body 20. The metal layer 30 is adjacent to the end of the right side of the tubular body 20 and spaced from the end of the right side. In the present embodiment, the metal layer 30 has a length of 20 to 60 mm and is made of a metal material having good toughness such as copper or aluminum.

Referring to FIGS. 4 and 5, the metal layer 30 of the tubular body 20 is partially constricted to obtain a reduced tube portion 40. Specifically, a pressing tool 50 is provided with the pressing tool 50 facing the left end of the metal layer 30. The left end of the metal layer 30 is pressed in the radial direction of the tube body 20 in the direction toward the central axis until the left side of the metal layer 30 is curled in a conical shape. At this time, since the metal layer 30 has plasticity and stress, it is closely attached to the capillary structure 21 of the inner wall of the pipe body 20. In the present embodiment, the constricted portion 40 divides the left and right sides of the tubular body 20 into the evaporation section 23 and the condensation section 24, and the length of the evaporation section 23 is smaller than the length of the condensation section 24. The constricted portion 40 has a central portion 41 and both end portions 42 at the left and right ends of the central portion 41. The outer diameter and the inner diameter of the central portion 41 are constant, and are smaller than the inner and outer diameters of the evaporating portion 23, and the outer diameters of the both end portions 42. Both the inner diameter and the inner diameter are gradually increased in a direction away from the central portion 41 until it is equivalent to the diameter of the evaporation section 23 or the condensation section 24. Since the left side of the metal layer 30 has a hollow conical shape, the metal layer 30 isolates the left and right portions of the cavity 22 of the tubular body 20, and the capillary structure 21 extends along the inner wall of the tubular body 20 from the evaporation section 23 to the condensation section 24. A liquid working fluid channel. The length of the metal layer 30 within the condensation section 24 is 10 mm.

Both ends of the pipe body 20 are evacuated, injected, and sealed, and the pipe body 20 is crushed.

Referring to FIG. 6, two pairs of through holes 25 are formed at both ends of the evaporation section 23 and the condensation section 24, respectively.

Referring to Figure 7, two hollow metal tubes 60 are provided which are connected in series to the corresponding evaporation section 23 and the through holes 25 of the condensation section 24 to form two vapor passages 61. In this way, the heat pipe 1 is completed.

Referring to FIG. 8, the number of through holes 25 is four, and four metal pipes 60 are connected in series to the corresponding evaporation holes 23 and the through holes 25 of the condensation section 24, thus forming four steam passages 61. The number of the through holes 25 and the metal pipe 60 is not limited.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

1. . . Heat pipe

10, 20. . . Tube body

11, 21. . . Capillary structure

12, 22. . . Cavity

13, 40. . . Shrink tube

131, 41. . . Central

132, 42. . . Ends

14,23. . . Evaporation section

15, 24. . . Condensation section

16, 30. . . Metal layer

161. . . Left end

162. . . Right end

17, 25. . . Through hole

18, 60. . . Metal tube

181, 61. . . Steam passage

50. . . Extrusion tool

Fig. 1 is a schematic view showing the structure of a heat pipe according to a first embodiment of the present invention.

Fig. 2 is a schematic view showing a pipe body in which an inner wall is attached with a capillary structure in the method of manufacturing the heat pipe shown in Fig. 1.

Figure 3 is a schematic view of the metal tube after it has been inserted into the tube body.

4 and 5 are schematic views showing a state in which a pipe body inserted into a metal pipe is partially contracted.

Fig. 6 is a schematic view showing the two ends of the pipe body of Fig. 5 welded and sealed and crushed, and two pairs of through holes are formed on the side walls of both ends of the pipe body.

Fig. 7 is a schematic view showing the two pairs of through holes connected to the pipe body of Fig. 6 by two metal thin tubes.

Fig. 8 is a schematic structural view of a heat pipe according to a second embodiment of the present invention.

1. . . Heat pipe

10. . . Tube body

11. . . Capillary structure

12. . . Cavity

13. . . Shrink tube

131. . . Central

132. . . Ends

14. . . Evaporation section

15. . . Condensation section

16. . . Metal layer

161. . . Left end

162. . . Right end

17. . . Through hole

18. . . Metal tube

181. . . Steam passage

Claims (10)

A heat pipe comprising a hollow and sealed end pipe body, the inner wall of the pipe body is provided with a capillary structure, the cavity is provided with a cavity body, and the cavity is provided with a working fluid, and the improvement is that the pipe body comprises evaporation a segment and a condensation section, the evaporation section and the condensation section are isolated from each other, the capillary structure extending from the evaporation section to the condensation section along the inner wall of the tube to form a liquid working fluid passage, wherein the evaporation section and the condensation section are each provided with at least one through hole, and The at least one through hole is connected in series by at least one hollow metal tube to form at least one steam passage. The heat pipe according to claim 1, wherein the tube body at the intersection of the evaporation section and the condensation section is further provided with a metal layer separating the evaporation section and the condensation section, the metal layer having a tapered shape toward the condensation section Up to the left end of the closure and a right end connected to the left end, the left and right ends of the metal layer are bonded to the capillary structure in the tube body. The heat pipe according to claim 1, wherein the pipe body forms a shrinkage pipe portion between the evaporation section and the condensation section at a position where the metal layer is disposed, and an inner diameter and an outer diameter of the shrinkage pipe portion They are smaller than the inner and outer diameters of the pipe body, respectively. The heat pipe according to claim 3, wherein the shrink pipe portion has a middle portion and two end portions at the left and right ends of the middle portion, and the outer diameter and the inner diameter of the middle portion are constant and smaller than the inner portion of the pipe body, respectively. The outer diameter and the outer diameter of the both end portions gradually increase in a direction away from the middle portion until they are equal to the outer diameter and the inner diameter of the tube body, respectively. The heat pipe of claim 1, wherein the length of the evaporation section is smaller than the length of the condensation section. A heat pipe manufacturing method includes the following steps:
Providing a tube body having a capillary structure on an inner wall thereof, a cavity formed in the tube body, the tube body comprising an evaporation section and a condensation section;
Isolating the evaporation section and the condensation section, and only causing the capillary structure to extend from the evaporation section to the condensation section along the inner wall of the tube to form a liquid working fluid passage;
Vacuuming, injecting and sealing the evaporation section and the condensation section of the pipe body respectively;
Separating at least one through hole in each of the evaporation section and the condensation section of the pipe body;
At least one metal tube is provided in series on the corresponding at least one through hole of the evaporation section and the condensation section, thus forming at least one steam passage. The heat pipe manufacturing method according to claim 6, wherein the step of "separating the evaporation section and the condensation section" further comprises the following steps:
Inserting and positioning an annular metal layer between the evaporation section and the condensation section of the pipe body to make the metal layer closely adhere to the capillary structure in the pipe body;
Extending the tube at the metal layer of the tube body to obtain a shrink tube portion, wherein the inner diameter and the outer diameter of the tube portion are smaller than the inner diameter and the outer diameter of the tube body, respectively, so that the metal layer is adjacent to the condensation portion One end of the metal layer is tapered toward the condensation section until the other end of the metal layer is in close contact with the capillary structure of the evaporation section, so that the metal layer is used to evaporate the cavity and the condensation section of the tube body. isolation. The heat pipe manufacturing method according to claim 7, wherein the pipe body is made of a heat conductive metal material. The heat pipe manufacturing method according to claim 7, wherein the capillary structure adopts a grooved capillary structure formed by directly forming a plurality of small axial grooves on the inner surface of the pipe body, using a metal copper mesh or fiber. The wire mesh capillary structure formed by the bundle weaving or the sintered capillary structure formed by the sintering process using ceramic powder or metal powder. The heat pipe manufacturing method according to claim 7, wherein the shrink pipe portion has a middle portion and both end portions at the left and right ends of the middle portion, and the outer diameter and the inner diameter of the middle portion are constant and smaller than the tube body respectively. The inner diameter and the outer diameter, both the outer diameter and the inner diameter of the both end portions gradually increase in a direction away from the middle portion until they are equal to the outer diameter and the inner diameter of the tube body, respectively.