Heat pipe

Abstract

A heat pipe includes a pipe body and a composite capillary structure. The pipe body includes an evaporation section, a condensation section, and a transport section. The evaporation section and the condensation section are respectively connected to opposite ends of the transport section. The composite capillary structure includes a first capillary structure and at least one second capillary structure. The first capillary structure is grooved and stacked on the pipe body. The at least one second capillary structure is at least partially stacked on the first capillary structure. The first capillary structure and the at least one second capillary structure extend from the evaporation section to the condensation section. The thickness of the composite capillary structure located in the evaporation section varies.

Description

Technical Field

[0001] This invention relates to a heat pipe, and more particularly to a heat pipe with a varying thickness of capillary structure. Prior Technology

[0002] Electronic devices or machinery generate high temperatures during operation, so manufacturers typically install heat pipes to dissipate heat. Heat pipes utilize the evaporation and condensation of internal cooling fluids to achieve rapid and uniform temperature distribution.

[0003] In detail, the liquid coolant in a heat pipe absorbs heat at the evaporation end and then vaporizes, moving towards the condensation end under vapor pressure. At the condensation end, the gaseous coolant releases heat and condenses back into liquid coolant. This liquid coolant then flows back to the evaporation end through the capillary structure inside the heat pipe, absorbs heat again, and evaporates, thus completing the cooling cycle. However, the cooling cycle efficiency achieved by the current capillary structure inside the heat pipe is still insufficient. Therefore, how to further improve the efficiency of heat pipes in dissipating heat from electronic devices or machinery during operation is one of the problems that researchers should solve. Summary of the Invention

[0004] The present invention provides a heat pipe to further improve the efficiency of heat pipe in dissipating heat from electronic devices or machinery during operation.

[0005] One embodiment of the present invention discloses a heat pipe comprising a tube body and a composite capillary structure. The tube body includes an evaporation section, a condensation section, and a transport section. The evaporation section and the condensation section are respectively connected to opposite ends of the transport section. The composite capillary structure includes a first capillary structure and at least one second capillary structure. The first capillary structure is grooved and stacked on the tube body. At least one second capillary structure is at least partially stacked on the first capillary structure. The first capillary structure and at least one second capillary structure extend from the evaporation section to the condensation section. The thickness of the composite capillary structure located in the evaporation section varies.

[0006] According to the heat pipe of the above embodiment, since the total thickness of the composite capillary structure in the evaporation section varies, in addition to the fact that the part with the smallest total thickness of the composite capillary structure in the evaporation section can be provided by the high capillary force of the second capillary structure so that the cooling fluid can be continuously returned to the evaporation section and delay dry burning, and the part with the largest total thickness of the composite capillary structure in the evaporation section can be provided by the high permeability of the first capillary structure and the high capillary force of the second capillary structure so that the cooling fluid can be returned to the evaporation section more quickly, the thermal resistance of the evaporation section can also be reduced, thus further improving the heat dissipation efficiency of the heat pipe.

[0007] The above description of the content of this invention and the following description of the embodiments are used to demonstrate and explain the principles of this invention, and to provide a further explanation of the scope of the patent application of this invention. Simple Explanation of the Diagram

[0008] Figure 1 is a three-dimensional schematic diagram of a heat pipe according to the first embodiment of the present invention. Figure 2 is a cross-sectional view of the heat pipe in Figure 1. Figure 3 is a partially enlarged cross-sectional view of the heat pipe in Figure 1. Figure 4 is a cross-sectional view of the heat pipe along section line 4-4 in Figure 3. Figure 5 is a cross-sectional view of the heat pipe along section line 5-5 of Figure 3. Figure 6 is a cross-sectional schematic diagram of the heat pipe according to the second embodiment of the present invention. Figure 7 is a partially enlarged cross-sectional view of the heat pipe in Figure 6. Figure 8 is a cross-sectional view of the heat pipe along section line 8-8 of Figure 7. Figure 9 is a cross-sectional view of the heat pipe along section line 9-9 of Figure 7. Implementation

[0009] Please refer to Figures 1 to 3. Figure 1 is a perspective view of the heat pipe according to the first embodiment of the present invention. Figure 2 is a cross-sectional view of the heat pipe of Figure 1. Figure 3 is a partially enlarged cross-sectional view of the heat pipe of Figure 1.

[0010] The heat pipe 10 in this embodiment is used to contain a cooling fluid (not shown). The cooling fluid is, for example, water, a refrigerant, or an alcohol liquid such as methanol or ethanol. The heat pipe 10 includes a pipe body 11 and a composite capillary structure 12. The pipe body 11 includes an evaporation section 111, a condensation section 112, and a transport section 113. The evaporation section 111 is thermally coupled to a heat source (not shown) and is connected to the condensation section 112 at opposite ends of the transport section 113. Thermal coupling refers to thermal contact or connection through other heat-conducting media.

[0011] Please refer to Figures 4 and 5 together. Figure 4 is a cross-sectional view of the heat pipe along section 4-4 of Figure 3. Figure 5 is a cross-sectional view of the heat pipe along section 5-5 of Figure 3.

[0012] The composite capillary structure 12 includes a first capillary structure 121 and a second capillary structure 122. The first capillary structure 121 is grooved and stacked on the tube body 11, for example, integrally formed with the tube body 11. The second capillary structure 122 is, for example, metal powder, metal mesh, or a combination thereof, and is stacked on the first capillary structure 121. The first capillary structure 121 and the second capillary structure 122 extend from the evaporation section 111 to the condensation section 112. The permeability of the grooved first capillary structure 121 is greater than the permeability of the metal powder, metal mesh, or combination thereof second capillary structure 122, and the capillary force of the grooved first capillary structure 121 is less than the capillary force of the metal powder, metal mesh, or combination thereof second capillary structure 122.

[0013] In this embodiment, the thickness of the first capillary structure 121 located in the evaporation section 111 increases from the end furthest from the condensation section 112 to the end closest to the condensation section 112, so that the thickness of the composite capillary structure 12 in the evaporation section 111 has a continuous variation. That is, the first capillary structure 121 located in the evaporation section 111 has a continuous inclined structure. The larger the size of the heat source, the longer the length of the first capillary structure 121 located in the evaporation section 111.

[0014] In this embodiment, since the thickness of the groove-shaped first capillary structure 121 located in the evaporation section 111 increases from one end away from the condensation section 112 to the one end closer to the condensation section 112, and the capillary force of the groove-shaped first capillary structure 121 is less than the capillary force of the second capillary structure 122 composed of metal powder, metal mesh, or a combination thereof, the composite capillary structure 12 closer to the heat source in the evaporation section 111 has a higher capillary force. This allows the high capillary force provided by the second capillary structure 122, composed of metal powder, metal mesh, or a combination thereof, to penetrate even at the point where the total thickness of the composite capillary structure 12 in the evaporation section 111 is minimal. To delay dry burning and ensure the continuous return of cooling fluid to the evaporation section 111, the composite capillary structure 12 in the evaporation section 111, at its thickest point, benefits from the high permeability provided by the grooved first capillary structure 121 and the high capillary force provided by the second capillary structure 122. This allows the cooling fluid to return to the evaporation section 111 more quickly. Furthermore, the increasing sections of the composite capillary structure 12 in the evaporation section 111, through the permeability provided by the first capillary structure 121 and the capillary force provided by the second capillary structure 122, not only facilitate the return of cooling fluid to the evaporation section 111 but also reduce the thermal resistance of the evaporation section 111. In this way, the heat dissipation efficiency of the heat pipe 10 can be further improved.

[0015] In this embodiment, the length L of the first capillary structure 121 located in the evaporation section 111 is, for example, greater than or equal to 10 mm and less than or equal to 200 mm.

[0016] In this embodiment, the thickness T1 of the first capillary structure 121 located at one end of the evaporation section 111 and near the condensation section 112 is, for example, greater than or equal to 0.1 mm and less than or equal to 1 mm. Furthermore, the thickness T1 of the first capillary structure 121 located at one end of the evaporation section 111 and near the condensation section 112 is, for example, greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

[0017] In this embodiment, the tube 11 may also have an inner wall surface 114. The first capillary structure 121 located in the evaporation section 111 may also have an inclined surface 1211. The inclined surface 1211 is opposite to the inner wall surface 114. The angle R between the inclined surface 1211 and the inner wall surface 114 is, for example, greater than or equal to 0.1 degrees and less than or equal to 6.5 degrees. More specifically, the angle R between the inclined surface 1211 and the inner wall surface 114 is, for example, greater than or equal to 0.1 degrees and less than or equal to 3.5 degrees.

[0018] In this embodiment, the first capillary structure 121 is integrally formed with the tube body 11, but this is not a limitation. In other embodiments, the first capillary structure and the tube body may be separate components, and the first capillary structure may be stacked on the tube body through other connection methods.

[0019] In this embodiment, the number of second capillary structures 122 is only one, but it is not limited to this. In other embodiments, the number of second capillary structures may be two or more.

[0020] As shown in Figure 2, in this embodiment, a cooling fluid is provided inside the heat pipe 10. When the liquid cooling fluid is heated in the evaporation section 111, which is thermally coupled to the heat source, it vaporizes into a gaseous cooling fluid. The gaseous cooling fluid flows in direction A in the transmission section 113 to the condensation section 112, which is away from the heat source, and condenses into a liquid cooling fluid. The liquid cooling fluid flows back to the evaporation section 111 in direction B through the permeability of the first capillary structure 121 and the capillary force of the second capillary structure 122, and is heated again to vaporize into a gaseous cooling fluid, thereby achieving the effect of cooling circulation.

[0021] In the first embodiment, the first capillary structure 121 located in the evaporation section 111 has a continuous inclined structure, but is not limited thereto. In other embodiments, please refer to Figures 6 and 7. Figure 6 is a cross-sectional schematic diagram of the heat pipe according to a second embodiment of the present invention. Figure 7 is a partially enlarged cross-sectional schematic diagram of the heat pipe of Figure 6.

[0022] The heat pipe 10A in this embodiment is similar to the heat pipe 10 in the first embodiment. Therefore, the differences between this embodiment and the first embodiment will be described below, and the similarities will not be repeated. In this embodiment, the heat pipe 10A is used to contain a cooling fluid (not shown). The cooling fluid is, for example, water, refrigerant, or an alcohol liquid such as methanol or ethanol. The heat pipe 10A includes a pipe body 11 and a composite capillary structure 12A. The pipe body 11 includes an evaporation section 111, a condensation section 112, and a transport section 113. The evaporation section 111 is thermally coupled to a heat source (not shown) and is connected to the condensation section 112 at opposite ends of the transport section 113.

[0023] Please refer to Figures 8 and 9 together. Figure 8 is a cross-sectional view of the heat pipe along section 8-8 of Figure 7. Figure 9 is a cross-sectional view of the heat pipe along section 9-9 of Figure 7.

[0024] The composite capillary structure 12A includes a first capillary structure 121A and a second capillary structure 122A. The first capillary structure 121A is grooved and stacked on the tube body 11. The second capillary structure 122A is, for example, metal powder, metal mesh, or a combination thereof, and is stacked on the tube body 11 and the first capillary structure 121A. The first capillary structure 121A and the second capillary structure 122A extend from the evaporation section 111 to the condensation section 112.

[0025] In this embodiment, the first capillary structure 121A located in the evaporation section 111 includes a plurality of spacers 121A1. These spacers 121A1 are stacked on the tube body 11 at intervals. That is, the first capillary structure 121A located in the evaporation section 111 has a discontinuous spacer structure. The second capillary structure 122A located in the evaporation section 111 is stacked on the tube body 11 and these spacers 121A1, and the thickness of the second capillary structure 122A located in the evaporation section 111 and stacked on these spacers 121A1 is, for example, smaller than that of the second capillary structure 122A located in the evaporation section 111 and stacked on the tube body 11, so that the thickness of the composite capillary structure 12A located in the evaporation section 111 has a discontinuous variation. That is, the location where only the second capillary structure 122A is provided is the location with the smallest total thickness of the composite capillary structure 12A, and the location where both the first capillary structure 121A and the second capillary structure 122A are provided is the location with the largest total thickness of the composite capillary structure 12A. The second capillary structure 122A stacked on the tube body 11 is connected to the second capillary structure 122A stacked on these intervals 121A1. In addition, the larger the size of the heat source, the longer the total length of the first capillary structure 121A located in the evaporation section 111.

[0026] In this embodiment, since the first capillary structure 121A located in the evaporation section 111 includes multiple spacers 121A1, and these spacers 121A1 are stacked at intervals on the tube body 11, in addition to the high capillary force provided by the second capillary structure 122A in the evaporation section 111 where only metal powder, metal mesh or a combination thereof are provided, the cooling fluid can be continuously returned to the evaporation section 111 to delay dry burning, and since the evaporation section 111 does not have the groove-shaped first capillary structure 121A and does not have the thermal resistance generated by the first capillary structure 121A, the overall thermal resistance of the evaporation section 111 can be reduced, and the high permeability provided by the first capillary structure 121A and the high capillary force provided by the second capillary structure 122A in the evaporation section 111 can be used to allow the cooling fluid to return to the evaporation section 111 more quickly. This will further improve the heat dissipation efficiency of heat pipe 10A.

[0027] In this embodiment, the thickness T2 of the first capillary structure 121A located in the evaporation section 111 is, for example, greater than or equal to 0.01 mm and less than or equal to 1 mm. Furthermore, the thickness T2 of the first capillary structure 121A located in the evaporation section 111 is, for example, greater than or equal to 0.01 mm and less than or equal to 0.7 mm. Additionally, the thickness of the first capillary structure 121A located in the transmission section 113 is, for example, greater than or equal to 0.03 mm and less than or equal to 1 mm, and the width of the first capillary structure 121A located in the transmission section 113 is, for example, greater than or equal to 0.03 mm and less than or equal to 0.6 mm.

[0028] In this embodiment, the thickness T3 of the second capillary structure 122A located in the evaporation section 111 is, for example, greater than or equal to 0.3 mm and less than or equal to 10 mm, but is not limited thereto, as long as the thickness of the second capillary structure 122A stacked on the tube body 11 is the same as the thickness of the second capillary structure 122A stacked on these spacers 121A1. The thickness T4 of the second capillary structure 122A located in the condensation section 112 and the thickness T5 of the second capillary structure 122A located in the transmission section 113 are, for example, greater than or equal to 0.3 mm and less than or equal to 12 mm.

[0029] In this embodiment, the ratio of the total length of these spacer portions 121A1 to the total length of the distance between any two adjacent spacer portions 121A1 is, for example, greater than or equal to 1 / 10 and less than or equal to 1. Furthermore, the ratio of the total length of these spacer portions 121A1 to the total length of the distance between any two adjacent spacer portions 121A1 is, for example, greater than or equal to 1 / 10 and less than or equal to 1 / 3. That is, the total length of these spacer portions 121A1 is less than or equal to the total length of the distance between any two adjacent spacer portions 121A1.

[0030] In this embodiment, the ratio of the total length of these spacers 121A1 to the total length of the distance between any two adjacent spacers 121A1 is greater than or equal to 1 / 10 and less than or equal to 1 / 3, but is not limited thereto. In other embodiments, the ratio of the total length of these spacers to the total length of the distance between any two adjacent spacers may also be, for example, greater than or equal to 1 and less than or equal to 10. That is, the total length of these spacers is greater than or equal to the total length of the distance between any two adjacent spacers.

[0031] According to the heat pipe of the above embodiment, since the total thickness of the composite capillary structure in the evaporation section varies, in addition to the fact that the part with the smallest total thickness of the composite capillary structure in the evaporation section can be provided by the high capillary force of the second capillary structure so that the cooling fluid can be continuously returned to the evaporation section and delay dry burning, and the part with the largest total thickness of the composite capillary structure in the evaporation section can be provided by the high permeability of the first capillary structure and the high capillary force of the second capillary structure so that the cooling fluid can be returned to the evaporation section more quickly, the thermal resistance of the evaporation section can also be reduced, thus further improving the heat dissipation efficiency of the heat pipe.

[0032] Although the present invention has been disclosed above with reference to the foregoing embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of patent protection of the present invention shall be determined by the scope of the patent application attached to this specification.

[0033] 10,10A: Heat pipe 11: Pipe body 111: Evaporation Section 112: Condensation section 113: Transmission segment 114:Inner wall surface 12,12A: Composite capillary structure 121, 121A: First capillary structure 1211: Incline 121A1: Spacing section 122, 122A: Second capillary structure A, B: Direction L: Length T1~T5: Thickness R: angle

Claims

1. A heat pipe, comprising: a pipe body including an evaporation section, a condensation section, and a transport section, the evaporation section and the condensation section being respectively connected to opposite ends of the transport section; and a composite capillary structure including a first capillary structure and at least one second capillary structure, the first capillary structure being grooved and stacked on the pipe body, the at least one second capillary structure being at least partially stacked on the first capillary structure, and the first capillary structure and the at least one second capillary structure extending from the evaporation section to the condensation section; wherein, The thickness of the first capillary structure of the composite capillary structure located in the evaporation section increases along the axial direction of the tube body from one end away from the condensation section to one end closer to the condensation section, so that the thickness of the composite capillary structure located in the evaporation section has a continuous variation.

2. The heat pipe as claimed in claim 1, wherein the length of the first capillary structure located in the evaporation section is greater than or equal to 10 mm and less than or equal to 200 mm.

3. The heat pipe as claimed in claim 1, wherein the thickness of the first capillary structure located at one end of the evaporation section and near the condensation section is greater than or equal to 0.1 mm and less than or equal to 1 mm.

4. The heat pipe as claimed in claim 3, wherein the thickness of the first capillary structure located at one end of the evaporation section and near the condensation section is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

5. The heat pipe as claimed in claim 1, wherein the pipe body has an inner wall surface, the first capillary structure located in the evaporation section has an inclined surface opposite to the inner wall surface, and the angle between the inclined surface and the inner wall surface is greater than or equal to 0.1 degrees and less than or equal to 6.5 degrees.

6. The heat pipe as claimed in claim 5, wherein the angle between the inclined surface and the inner wall surface is greater than or equal to 0.1 degrees and less than or equal to 3.5 degrees.

7. A heat pipe, comprising: a pipe body including an evaporation section, a condensation section, and a transport section, the evaporation section and the condensation section being respectively connected to opposite ends of the transport section; and a composite capillary structure including a first capillary structure and at least one second capillary structure, the first capillary structure being grooved and stacked on the pipe body, the at least one second capillary structure being at least partially stacked on the first capillary structure, and the first capillary structure and the at least one second capillary structure extending from the evaporation section to the condensation section; wherein, The first capillary structure located in the evaporation section includes a plurality of spacers that are stacked at intervals on the tube body. The at least one second capillary structure located in the evaporation section is stacked on the spacers and the tube body, so that the thickness of the composite capillary structure located in the evaporation section has a discontinuous variation.

8. The heat pipe as claimed in claim 7, wherein the thickness of the at least one second capillary structure located in the evaporation section and stacked in the spacers is less than that of the at least one second capillary structure located in the evaporation section and stacked in the pipe body.

9. The heat pipe as claimed in claim 8, wherein the thickness of the first capillary structure is greater than or equal to 0.01 mm and less than or equal to 1 mm.

10. The heat pipe as claimed in claim 9, wherein the thickness of the first capillary structure is greater than or equal to 0.01 mm and less than or equal to 0.7 mm.

11. The heat pipe as claimed in claim 8, wherein the thickness of the at least one second capillary structure located in the evaporation section is greater than or equal to 0.3 mm and less than or equal to 10 mm.

12. The heat pipe as claimed in claim 8, wherein the ratio of the total length of the spacers to the total length of the distance between any two adjacent spacers is greater than or equal to 1 / 10 and less than or equal to 1.

13. The heat pipe as claimed in claim 12, wherein the ratio of the total length of the spacers to the total length of the distance between any two adjacent spacers is greater than or equal to 1 / 10 and less than or equal to 1 / 3.

14. The heat pipe as claimed in claim 8, wherein the ratio of the total length of the spacers to the total length of the distance between any two adjacent spacers is greater than or equal to 1 and less than or equal to 10.

15. The heat pipe as claimed in claim 1, wherein the at least one second capillary structure is metal powder, metal braided mesh, or a combination thereof.

16. The heat pipe as claimed in claim 1, wherein the height of the at least one second capillary structure located in the evaporation section varies.

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