US20240183621A1

US20240183621A1 - Heat pipe

Info

Publication number: US20240183621A1
Application number: US18/242,432
Authority: US
Inventors: Xue Mei WANG
Original assignee: Vast Glory Electronics and Hardware and Plastic Huizhou Ltd
Current assignee: Purple Cloud Development Pte Ltd
Priority date: 2022-12-06
Filing date: 2023-09-05
Publication date: 2024-06-06
Also published as: CN118149629A; TWM641311U

Abstract

A heat pipe including an outer pipe, a composite capillary structure and an inner pipe. The outer pipe includes a vaporization section, a condensation section and a transmission section. The vaporization section and the condensation section are connected to two opposite sides of the transmission section. The outer pipe has an accommodating chamber. The accommodating chamber extends from the vaporization section to the condensation section. The composite capillary structure is located in the accommodating chamber of the outer pipe. The inner pipe is located in the accommodating chamber in the transmission section. The inner pipe divides the accommodating chamber in the transmission section into an inner channel and an outer channel. The inner channel and the outer channel are in fluid communication with the accommodating chamber in the vaporization section and the condensation section. The composite capillary structure is partially located in the outer channel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 202211557455.4 filed in China, on Dec. 6, 2022, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a heat pipe, more particularly to a heat pipe having an inner pipe.

BACKGROUND

Generally, when an electronic device or equipment is in operation, a great amount of heat may be generated therefrom. Thus, heat pipes are usually adopted in the electronic device or equipment to dissipate heat. The heat pipes can facilitate to dissipate heat via a phase change between working fluid therein. Specifically, after the liquid working fluid in a heat pipe absorbs heat at a vaporization end of the heat pipe, the liquid working fluid vaporizes into the gaseous working fluid, and a vapor pressure drives the gaseous working fluid to flow to a condensation end of the heat pipe. After the gaseous working fluid releases heat at the condensation end and is condensed into the liquid working fluid, the liquid working fluid flows back to the vaporization end via a capillary structure inside the heat pipe, thereby completing a cooling cycle.
In present, there is no fluid distribution built in the heat pipe for liquid and gaseous working fluid, such that the liquid and the gaseous working fluid flow in the same channel. However, when the liquid and the gaseous working fluid flow together in the same channel in the heat pipe, the gaseous working fluid and the liquid working fluid may be interfered with each other, thereby reducing a cooling efficiency. Therefore, how to solve the aforementioned issue is one of the crucial topics in this field.

SUMMARY

The present disclosure provides a heat pipe which can improve the heat dissipation efficiency for the electronic device or equipment during operation.
One embodiment of the disclosure provides a heat pipe including an outer pipe, a composite capillary structure and at least one inner pipe. The outer pipe includes a vaporization section, a condensation section and a transmission section. The vaporization section and the condensation section are connected to two opposite sides of the transmission section. The outer pipe has an accommodating chamber. The accommodating chamber extends from the vaporization section to the condensation section. The composite capillary structure is located in the accommodating chamber of the outer pipe. The composite capillary structure includes a first capillary structure and a second capillary structure. The first capillary structure is stacked on the second capillary structure. The second capillary structure is stacked on the outer pipe. The first capillary structure is at least disposed in the vaporization section of the outer pipe. The at least one inner pipe is located in a portion of the accommodating chamber in the transmission section. The at least one inner pipe divides the portion of the accommodating chamber in the transmission section into at least one inner channel and at least one outer channel. The at least one inner channel and the at least one outer channel are in fluid communication with other portions of the accommodating chamber in the vaporization section and the condensation section. The composite capillary structure is partially located in the at least one outer channel.
According to the heat pipe as described in the above embodiments, since the inner pipe divides a portion of the accommodating chamber in the transmission section into an inner channel and an outer channel, the gaseous working fluid and the liquid working fluid are separated in the transmission section during the cooling cycle. That is, the gaseous working fluid and the liquid working fluid do not interfere with each other. Therefore, the gaseous working fluid and the liquid working fluid may flow without being resisted by each other, thereby improving the cooling efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present disclosure and wherein:

FIG. 1 is a perspective view of a heat pipe in accordance with a first embodiment of the disclosure;

FIG. 2 is a cross-sectional view of the heat pipe in FIG. 1 ;

FIG. 3 is a partially enlarged cross-sectional view of the heat pipe in FIG. 2 ;

FIG. 4 is a cross-sectional view of the heat pipe taken along a line 4-4 in FIG. 2 ;

FIG. 5 is a cross-sectional view of the heat pipe taken along a line 5-5 in FIG. 2 ;

FIG. 6 is a cross-sectional view of the heat pipe taken along a line 6-6 in FIG. 2 ;

FIG. 7 is a perspective view of an inner pipe of a heat pipe in accordance with a second embodiment of the disclosure;

FIG. 8 is a cross-sectional view of the heat pipe in FIG. 7 ;

FIG. 9 is a cross-sectional view of a heat pipe in accordance with a third embodiment of the disclosure;

FIG. 10 is a cross-sectional view of a heat pipe in accordance with a fourth embodiment of the disclosure;

FIG. 11 is a cross-sectional view of a heat pipe in accordance with a fifth embodiment of the disclosure;

FIG. 12 is a cross-sectional view of a heat pipe in accordance with a sixth embodiment of the disclosure; and

FIG. 13 is a cross-sectional view of a heat pipe in accordance with a seventh embodiment of the disclosure.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
In addition, the terms used in the present disclosure, such as technical and scientific terms, have its own meanings and can be comprehended by those skilled in the art, unless the terms are additionally defined in the present disclosure. That is, the terms used in the following paragraphs should be read on the meaning commonly used in the related fields and will not be overly explained, unless the terms have a specific meaning in the present disclosure.
Please refer to FIG. 1 to FIG. 3 , where FIG. 1 is a perspective view of a heat pipe 10 in accordance with a first embodiment of the disclosure, FIG. 2 is a cross-sectional view of the heat pipe 10 in FIG. 1 , and FIG. 3 is a partially enlarged cross-sectional view of the heat pipe 10 in FIG. 2 .
In this embodiment, the heat pipe 10 is configured to accommodate a working fluid (not shown). The working fluid is, for example, water or refrigerant. The heat pipe 10 includes an outer pipe 11, a composite capillary structure 12 and an inner pipe 13. The outer pipe 11 includes a vaporization section 111, a condensation section 112 and a transmission section 113. The vaporization section 111 and the condensation section 112 are connected to two opposite sides of the transmission section 113. The outer pipe 11 has an accommodating chamber 114 and an inner surface 115. The accommodating chamber 114 extends from the vaporization section 111 to the condensation section 112. The inner surface 115 surrounds and forms the accommodating chamber 114.
The composite capillary structure 12 is located in the accommodating chamber 114 of the outer pipe 11, and includes a first capillary structure 121 and a second capillary structure 122. The first capillary structure 121 is, for example, a metal mesh, a sintered powder structure or a sintered ceramic structure, and the second capillary structure 122 is, for example, a microgroove, a metal mesh, a sintered powder structure or a sintered ceramic structure. The first capillary structure 121 is stacked on the second capillary structure 122. The first capillary structure 121 and the second capillary structure 122 are, for example, recesses and protrusions matching each other. The first capillary structure 121, for example, extends from the vaporization section 111 to the transmission section 113 of the outer pipe 11. The second capillary structure 122 is located on the inner surface 115, and extends from the vaporization section 111 to the condensation section 112.
The inner pipe 13 is located in the accommodating chamber 114 in the transmission section 113, and a length of the inner pipe 13 is less than or equal to a length of the transmission section 113. The inner pipe 13 divides a portion of the accommodating chamber 114 in the transmission section 113 into an inner channel 1141 and an outer channel 1142. That is, the inner channel 1141 and the outer channel 1142 are designed for fluid distribution. The inner channel 1141 and the outer channel 1142 are in fluid communication with two portions of the accommodating chamber 114 which are respectively in the vaporization section 111 and the condensation section 112. The composite capillary structure 12 is partially located in the outer channel 1142.
In this embodiment, since the inner channel 1141 and the outer channel 1142 are designed for fluid distribution, the gaseous working fluid can flow in the inner channel 1141, and the liquid working fluid can flow in the outer channel 1142. That is, the gaseous working fluid and the liquid working fluid are separated without interfering with each other. Therefore, the gaseous working fluid and the liquid working fluid may flow without being resisted by each other, thereby improving a cooling efficiency.
In this embodiment, the heat pipe 10 includes one inner pipe 13, and is configured for a round pipe or a flat pipe.
In this embodiment, a length of the inner pipe 13 is less than or equal to a length of the transmission section 113, but the disclosure is not limited thereto. In other embodiments, a length of the inner pipe may be less than or equal to a sum of a length of the transmission section and a predetermined length. The predetermined length is, for example, 5 millimeters (mm) to 15 mm. That is, the length of the inner pipe may be greater than the length of the transmission section by 5 mm to 15 mm.
Please refer to FIG. 4 to FIG. 6 , where FIG. 4 is a cross-sectional view of the heat pipe 10 taken along a line 4-4 in FIG. 2 , FIG. 5 is a cross-sectional view of the heat pipe 10 taken along a line 5-5 in FIG. 2 , and FIG. 6 is a cross-sectional view of the heat pipe 10 taken along a line 6-6 in FIG. 2 .
In this embodiment, a porosity of a portion of the composite capillary structure 12 located in the vaporization section 111 is less than a porosity of another portion of the composite capillary structure 12 located in the condensation section 112. The greater the porosity of the composite capillary structure 12 is (that is, the larger the powder particles of the composite capillary structure 12 are), the greater a permeability thereof is. Therefore, a permeability of the portion of the composite capillary structure 12 in the condensation section 112 is greater than a permeability the portion of the composite capillary structure 12 in the vaporization section 111, such that after the gaseous working fluid condenses into the liquid working fluid, the liquid working fluid can rapidly permeate into the portion of the composite capillary structure 12 in the condensation section 112. In addition, a capillary force of the portion of the composite capillary structure 12 in the vaporization section 111 is greater than a capillary force of the portion of the composite capillary structure 12 in the condensation section 112. Accordingly, the portion of the composite capillary structure 12 in the vaporization section 111 can drive the liquid working fluid to flow back to the vaporization section 111.
In this embodiment, the first capillary structure 121 extends from the vaporization section 111 to the transmission section 113 of the outer pipe 11, and the second capillary structure 122 extends from the vaporization section 111 to the condensation section 112. Accordingly, the overall thickness of the portion of the composite capillary structure 12 in the vaporization section 111 and the overall thickness of the portion of the composite capillary structure 12 in transmission section 113 are greater than the overall thickness of the portion of the composite capillary structure 12 in the condensation section 112. Since the thicknesses of the composite capillary structure 12 in different sections of the outer pipe 11 are different, the amount of the working fluid flowing in the composite capillary structure 12 in the different sections of the outer pipe 11 is different. Therefore, the composite capillary structure 12 with different thicknesses in the different sections of the outer pipe 11 can prevent the working fluid from being blocked when flowing in the composite capillary structure 12, thereby avoiding the cooling efficiency from reducing.
In this embodiment, the overall thicknesses of the composite capillary structure 12 in the vaporization section 111 and the transmission section 113 are substantially equal to each other, but the disclosure is not limited thereto; in some other embodiments, the overall thicknesses of the composite capillary structure in the vaporization section may be greater than the overall thicknesses of the composite capillary structure in the transmission section.
In this embodiment, a percentage of a ratio of a cross-sectional area of the inner pipe 13 to a cross-sectional area of the outer pipe 11 is, for example, greater than or equal to 30%.
Please refer to FIG. 2 again. The liquid working fluid in the heat pipe 10 is heated and vaporized into the gaseous working fluid in the vaporization section 111 close to a heat source. The gaseous working fluid flows to the condensation section 112 farthest away from the heat source along a direction A through the inner channel 1141, and condenses into the liquid working fluid. Then, the liquid working fluid flows back to the vaporization section 111 along a direction B through the outer channel 1142, and is heated and vaporized into the gaseous working fluid again, such that a cooling cycle can be completed.
Please refer to FIG. 7 and FIG. 8 , where FIG. 7 is a perspective view of an inner pipe 13A of a heat pipe 10A in accordance with a second embodiment of the disclosure, and FIG. 8 is a cross-sectional view of the heat pipe 10A in FIG. 7 .
The heat pipe 10A of this embodiment is similar to the heat pipe 10 of the first embodiment, the main difference between them will be described below, and the same parts between them can be referred to the aforementioned paragraphs with the reference to FIG. 1 to FIG. 6 and will not be repeatedly introduced hereinafter. In this embodiment, an inner pipe 13A of the heat pipe 10A has a plurality of through holes 131. The inner channel 1141 is in fluid communication with the outer channel 1142 through the through holes 131. When the gaseous working fluid flows in the transmission section 113 along a direction C, the gaseous working fluid may be partially condensed into the liquid working fluid in the transmission section 113 in advance. Therefore, the condensed liquid working fluid can flow back to the vaporization section 111 in advance along a direction D through the through holes 131 and the composite capillary structure 12 for continuing the cooling cycle, thereby improving the cooling efficiency.
Please refer to FIG. 9 , which is a cross-sectional view of a heat pipe 10B in accordance with a third embodiment of the disclosure. The heat pipe 10B of this embodiment is similar to the heat pipe 10 of the first embodiment, the main difference between them will be described below, and the same parts between them can be referred to the aforementioned paragraphs with the reference to FIG. 1 to FIG. 6 and will not be repeatedly introduced hereinafter. In this embodiment, the composite capillary structure 12B of the heat pipe 10B may not be recesses and protrusions matching each other. The heat pipe 10B includes only one inner pipe 13B, and the heat pipe 10B is a round pipe, but the disclosure is not limited thereto. In other embodiments, the heat pipe may be a flat pipe.
Please refer to FIG. 10 , which is a cross-sectional view of a heat pipe 10C in accordance with a fourth embodiment of the disclosure. The heat pipe 10C of this embodiment is similar to the heat pipe 10 of the first embodiment, the main difference between them will be described below, and the same parts between them can be referred to the aforementioned paragraphs with the reference to FIG. 1 to FIG. 6 and will not be repeatedly introduced hereinafter. In this embodiment, the composite capillary structure 12C of the heat pipe 10C may not be recesses and protrusions matching each other. An inner pipe 13C of the heat pipe 10C is offset from a center of a portion of an accommodating chamber 114C located in the transmission section 113. The heat pipe 10C includes only one inner pipe 13C, and the heat pipe 10C is a round pipe, but the disclosure is not limited thereto. In other embodiments, the heat pipe may be a flat pipe.
Please refer to FIG. 11 , which is a cross-sectional view of a heat pipe 10D in accordance with a fifth embodiment of the disclosure. The heat pipe 10D of this embodiment is similar to the heat pipe 10 of the first embodiment, the main difference between them will be described below, and the same parts between them can be referred to the aforementioned paragraphs with the reference to FIG. 1 to FIG. 6 and will not be repeatedly introduced hereinafter. In this embodiment, the composite capillary structure 12D of the heat pipe 10D may not be recesses and protrusions matching each other. The heat pipe 10D includes two inner pipes 13D, and the heat pipe 10D is a round pipe. Diameters of the two inner pipes 13D are equal to each other, and the two inner pipes 13D are arranged side by side. In addition, the composite capillary structure 12D is filled with a space between the two inner pipes 13D and the outer pipe 11 of the heat pipe 10D.
Please refer to FIG. 12 , which is a cross-sectional view of a heat pipe 10E in accordance with a sixth embodiment of the disclosure. The heat pipe 10E of this embodiment is similar to the heat pipe 10 of the first embodiment, the main difference between them will be described below, and the same parts between them can be referred to the aforementioned paragraphs with the reference to FIG. 1 to FIG. 6 and will not be repeatedly introduced hereinafter. In this embodiment, the composite capillary structure 12E of the heat pipe 10E may not be recesses and protrusions matching each other. The heat pipe 10E includes three inner pipes 13E, and the three inner pipes 13E are round pipes. Diameters of the three inner pipes 13E are equal to each other, and the three inner pipes 13E are in contact with one another. In addition, the composite capillary structure 12E is filled with a space between the three inner pipes 13E and the outer pipe 11 of the heat pipe 10E.
Please refer to FIG. 13 , which is a cross-sectional view of a heat pipe 10F in accordance with a seventh embodiment of the disclosure. The heat pipe 10F of this embodiment is similar to the heat pipe 10 of the first embodiment, the main difference between them will be described below, and the same parts between them can be referred to the aforementioned paragraphs with the reference to FIG. 1 to FIG. 6 and will not be repeatedly introduced hereinafter. In this embodiment, the composite capillary structure 12F of the heat pipe 10F may not be recesses and protrusions matching each other. The inner pipe 13F of the heat pipe 10F includes a first pipe 132, two second pipes 133 and a third pipe 134. A diameter of the first pipe 132 is greater than diameters of the two second pipes 133, and the diameters of the two second pipes 133 are greater than a diameter of the third pipe 134. The two second pipes 133 are located between the first pipe 132 and the third pipe 134. The heat pipe 10F is the round pipe. In addition, the composite capillary structure 12F is filled with a space between the inner pipe 13F and the outer pipe 11 of the heat pipe 10F.
According to the heat pipe as described in the above embodiments, since the inner pipe divides a portion of the accommodating chamber in the transmission section into an inner channel and an outer channel, the gaseous working fluid and the liquid working fluid are separated in the transmission section during the cooling cycle. That is, the gaseous working fluid and the liquid working fluid do not interfere with each other. Therefore, the gaseous working fluid and the liquid working fluid may flow without being resisted by each other, thereby improving the cooling efficiency.
In addition, the inner pipe has the plurality through holes. Therefore, after the gaseous working fluid is partially condensed into the liquid working fluid in the transmission section, the condensed liquid working fluid can flow back to the vaporization section in advance through the through holes and the composite capillary structure 12 for continuing a cooling cycle, thereby improving the cooling efficiency.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure. It is intended that the specification and examples be considered as exemplary embodiments only, with a scope of the disclosure being indicated by the following claims and their equivalents.

Claims

What is claimed is:

1. A heat pipe, comprising:

an outer pipe, comprising a vaporization section, a condensation section and a transmission section, wherein the vaporization section and the condensation section are connected to two opposite sides of the transmission section, the outer pipe has an accommodating chamber, and the accommodating chamber extends from the vaporization section to the condensation section;

a composite capillary structure, located in the accommodating chamber of the outer pipe, wherein the composite capillary structure comprises a first capillary structure and a second capillary structure, the first capillary structure is stacked on the second capillary structure, the second capillary structure is stacked on the outer pipe, and the first capillary structure is at least disposed in the vaporization section of the outer pipe; and

at least one inner pipe, located in a portion of the accommodating chamber in the transmission section, wherein the at least one inner pipe divides the portion of the accommodating chamber in the transmission section into at least one inner channel and at least one outer channel, the at least one inner channel and the at least one outer channel are in fluid communication with other portions of the accommodating chamber in the vaporization section and the condensation section, and the composite capillary structure is partially located in the at least one outer channel.

2. The heat pipe according to claim 1, wherein the first capillary structure is a metal mesh, a sintered powder structure or a sintered ceramic structure.

3. The heat pipe according to claim 2, wherein the second capillary structure is a microgroove, a metal mesh, a sintered powder structure or a sintered ceramic structure.

4. The heat pipe according to claim 1, wherein a thickness of the portion of the composite capillary structure in the vaporization section is different from a thickness of the portion of the composite capillary structure in the condensation section.

5. The heat pipe according to claim 1, wherein a capillary force of the portion of the composite capillary structure in the vaporization section is greater than a capillary force of the portion of the composite capillary structure in the condensation section.

6. The heat pipe according to claim 1, wherein a porosity of the portion of the composite capillary structure in the vaporization section is less than a porosity of the portion of the composite capillary structure in the condensation section.

7. The heat pipe according to claim 1, wherein the at least one inner pipe has a plurality of through holes, and the at least one inner channel is in fluid communication with the at least one outer channel through the plurality of through holes.

8. The heat pipe according to claim 1, wherein the heat pipe comprises two inner pipes, diameters of the two inner pipes are equal to each other, and the two inner pipes are arranged side by side.

9. The heat pipe according to claim 1, wherein the heat pipe comprises three inner pipes, diameters of the three inner pipes are equal to each other, and the three inner pipes are in contact with one another.

10. The heat pipe according to claim 1, wherein the at least one inner pipe comprises a first pipe, two second pipes and a third pipe, a diameter of the first pipe is greater than diameters of the two second pipes, the diameters of the two second pipes are greater than a diameter of the third pipe, and the two second pipes are located between the first pipe and the third pipe.

11. The heat pipe according to claim 1, wherein the at least one inner pipe is offset from a center of the portion of the accommodating chamber in the transmission section.

12. The heat pipe according to claim 1, wherein a percentage of a ratio of a cross-sectional area of the at least one inner pipe to a cross-sectional area of the outer pipe is greater than or equal to 30%.

13. The heat pipe according to claim 1, wherein a length of the at least one inner pipe is less than or equal to a length of the transmission section.

14. The heat pipe according to claim 1, wherein a length of the at least one inner pipe is less than or equal to a sum of a length of the transmission section and a predetermined length, and the predetermined length is 5 millimeters (mm) to 15 mm.