CN116419526A

CN116419526A - Phase change thermal management device

Info

Publication number: CN116419526A
Application number: CN202111635668.XA
Authority: CN
Inventors: 李奕嶒; 刘燕妮
Original assignee: Industrial Technology Research Institute ITRI
Current assignee: Industrial Technology Research Institute ITRI
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2023-07-11

Abstract

The invention provides a phase change thermal management device, which comprises a shell, a plurality of inner walls and a phase change heat storage material. The housing has an interior space. The inner walls are arranged in the inner space and are connected to form a plurality of accommodating cavities. The two adjacent accommodating cavities are communicated with each other through at least one through hole of the inner wall. The phase change heat storage material is positioned in at least part of the accommodating cavity.

Description

Phase change thermal management device

Technical Field

The invention relates to a phase change thermal management device.

Background

The problem of heat dissipation of electronic products has long been the object of research in this field of technology. Generally, a cooling fan and a water cooling system are generally considered to have better heat dissipation efficiency. However, since network communication devices, satellite electronic components, rechargeable batteries, and the like are often used outdoors or in space, and these use environments lack electric power, heat cannot be dissipated by a fan or a water cooling system, and only passive heat dissipation methods such as natural convection or radiation can be relied on.

In recent years, phase change materials have been widely used in passive heat sink devices, such as temperature plates. The phase change material which is solid or liquid at room temperature can absorb heat energy generated by a heat source and be converted into liquid or gas, thereby achieving the purpose of controlling the temperature of the heat source.

Disclosure of Invention

The invention provides a phase change thermal management device to increase heat dissipation and avoid the overheating problem of elements.

The phase change thermal management device disclosed by the embodiment of the invention comprises a shell, a plurality of inner walls and a phase change heat storage material. The shell is provided with an inner space. The inner walls are arranged in the inner space and are connected to form a plurality of accommodating cavities. The two adjacent accommodating cavities are communicated with each other through at least one through hole in one inner wall. The phase change heat storage material is positioned in at least part of the accommodating cavity.

According to the phase change thermal management device disclosed by the invention, when heat energy generated by an external heat source is transferred to the phase change thermal management device, the phase change heat storage material can absorb the heat energy so as to achieve the purpose of controlling the temperature of the external heat source, and the phase change heat storage material can flow into other adjacent accommodating cavities through the through holes. Therefore, if the phase change heat storage materials in the other accommodating cavities are not phase-changed yet, the phase change heat storage materials which absorb heat and are phase-changed can absorb heat energy through flowing to generate phase change, so that the temperature of an external heat source is stabilized. In addition, under the condition that the heat energy is intensively transferred to a specific area and the temperature of part of the accommodating cavity is high, the phase-change heat storage material which absorbs heat and changes phase can flow into the accommodating cavity with high temperature through the through hole, so that the amount of the phase-change heat storage material in the accommodating cavity with high temperature is increased, and the heat dissipation efficiency is improved.

The foregoing description of the invention and the following description of embodiments are presented to illustrate and explain the principles of the invention and to provide a further explanation of the invention as claimed.

Drawings

FIG. 1 is a schematic perspective view of a thermal phase change management device according to an embodiment of the invention;

FIG. 2 is a schematic cross-sectional view of the phase change thermal management device of FIG. 1;

FIG. 3 is an enlarged schematic view of a portion of the phase change thermal management device of FIG. 2;

FIG. 4 is a schematic cross-sectional view of a phase change thermal management device according to another embodiment of the invention;

FIGS. 5 a-5 b are schematic diagrams illustrating temperature distribution of a conventional temperature uniformity plate and a phase change thermal management device according to an embodiment of the present invention;

fig. 6 is a schematic diagram of an electronic product with a phase change thermal management device according to another embodiment of the present invention;

fig. 7 is a schematic diagram of an electronic product with a phase change thermal management device according to still another embodiment of the present invention;

FIG. 8 is a schematic view of a portion of a cavity of a thermal management device according to an embodiment of the invention;

FIG. 9 is a schematic diagram of a portion of a cavity of a thermal phase change management device according to an embodiment of the invention;

FIG. 10 is a schematic diagram of a portion of a cavity of a thermal management device for phase change according to an embodiment of the invention.

Symbol description

1a, 1b phase change thermal management device

10 shell body

110 interior space

20. 20b inner wall

200 holding cavity

210. 210b through hole

21 first inner wall

22 second inner wall

23 third inner wall

24 fourth inner wall

25 fifth inner wall

211. 212 groove

30 phase change heat storage material

40 surface modified coating

2 base

3 antenna

4 amplifier

5 thermal interface material

6 radiator

7 heat pipe

8 radiator fan

L1 width

L2 height

D aperture

V natural convection flow velocity

H radial dimension

S heat source

Detailed Description

The detailed features and advantages of the present invention will be set forth in the following detailed description, which is presented to enable any person skilled in the art to make and use the present invention, and in light of the present disclosure, the claims and the accompanying drawings, any person skilled in the art will readily understand the objects and advantages associated with the present invention. The following examples illustrate the aspects of the invention in further detail, but are not intended to limit the scope of the invention in any way.

Referring to fig. 1 and 2, fig. 1 is a schematic perspective view of a thermal phase change management device according to an embodiment of the invention. FIG. 2 is a schematic cross-sectional view of the phase change thermal management device of FIG. 1. In the present embodiment, the phase change thermal management device 1a includes a housing 10, an inner wall 20, and a phase change heat storage material 30.

The housing 10 is, for example and without limitation, a metal housing having an enclosed interior space 110. The number of the inner walls 20 is plural, which are disposed in the inner space 110 of the housing 10, and the inner walls 20 are connected to form a plurality of receiving cavities 200. More specifically, the ends of the inner wall 20 are connected to the inner surface of the housing 10, and the connection may be achieved by integrally or non-integrally forming means such as: the engaging and locking are not limited to this. As shown in fig. 1, these inner walls 20 are interlaced with each other to form a mesh-like stent structure. Fig. 1 and fig. 2 show that a plurality of inner walls 20 are staggered to form a plurality of square accommodating cavities 200, but the shape of the accommodating cavities 200 is not limited thereto. The material of the inner wall 20 may be selected from the group consisting of metal, plastic, polymer and combinations thereof.

Among these accommodation cavities 200, an inner wall 20 is provided between any two adjacent accommodation cavities 200, and the two adjacent accommodation cavities 200 communicate with each other via a through hole 210 on the inner wall 20. More specifically, the inner wall 20 may include a first inner wall 21, a second inner wall 22, a third inner wall 23, a fourth inner wall 24 and a fifth inner wall 25, wherein the first inner wall 21, the second inner wall 22 and the third inner wall 23 are arranged in parallel, the fourth inner wall 24 and the fifth inner wall 25 are arranged in parallel, and the fourth inner wall 24 and the fifth inner wall 25 are respectively staggered with the first inner wall 21, the second inner wall 22 and the third inner wall 23 to form the accommodating cavity 200. Wherein adjacent two of the receiving cavities 200 communicate with each other via the through holes 210 of the second inner wall 22. Likewise, any one of the receiving cavities 200 may communicate with the adjacent other receiving cavities 200 via the through holes 210 of the first, third, fourth, or fifth

inner walls

21, 23, 24, or 25. The through holes 210 on the inner walls 20 of the three adjacent receiving cavities 200 are continuously centered on the same axis or on different axes, and in addition, the openings of the through holes may be the same or different in size to increase the turbulence effect generated in the fluid flow process, so as to facilitate heat energy transfer. Fig. 1 and 2 show that the inner wall 20 between two adjacent receiving cavities 200 has a single through hole 210, but the number of through holes 210 is not limited thereto.

The phase change heat storage material 30 is located at least partially within the receiving cavity 200. Fig. 1 and 2 show the phase change thermal storage material 30 present in each of the receiving cavities 200, but in other embodiments there may be portions of the receiving cavities without the phase change thermal storage material.

The phase change thermal storage material 30 may be a solid phase change liquid phase thermal storage material or a liquid phase change gas phase thermal storage material. The solid-to-liquid phase change thermal storage material 30 may be selected from the group consisting of indium-bismuth-tin alloys, indium-gallium-tin alloys, paraffin (Paraffin), and combinations thereof. In addition, graphite or a foaming metal (not shown) may be added to the phase change heat storage material 30 to enhance the heat transfer capability of the phase change heat storage material 30. The foaming metal is, for example, aluminum foaming metal, copper foaming metal or nickel foaming metal.

When the heat energy generated by an external heat source (for example, a high-power chip in a network device, not shown) is transferred to the phase-change thermal management device 1a, the heat energy can sequentially pass through the housing 10 and the inner wall 20 to reach the phase-change heat storage material 30, and the phase-change heat storage material 30 absorbs the heat energy during the phase change process to further achieve the purpose of controlling the temperature of the external heat source. In the embodiment using the solid-phase-change liquid-phase heat storage material, the phase-change heat storage material 30 after phase change is in a liquid state, and at this time, the liquid-phase-change heat storage material 30 in any one of the accommodating cavities 200 can flow to other adjacent accommodating cavities 200 through the through holes 210 on the inner wall 20. If the phase change heat storage material 30 in the other accommodating cavity 200 is in a solid state, the liquid phase change heat storage material 30 can make the phase change of the solid phase change heat storage material 30 take place to exert its function of absorbing heat energy. In addition, in the case that the heat energy is more intensively transferred to the specific area and the temperature of the partial accommodating cavity 200 is higher, the liquid phase change heat storage material 30 can flow into the accommodating cavity 200 with high temperature through the through hole 210, so as to increase the distribution range of the phase change heat storage material 30 in the Gao Wenrong accommodating cavity 200, thereby improving the heat dissipation efficiency.

In this embodiment, the phase change thermal management device 1a may further include a surface modifying coating 40 disposed on each surface of the inner wall 20. The surface modifying coating 40 may be cobalt, nickel, molybdenum, titanium, or a combination thereof. Fig. 1 and 2 show the surface modifying coating 40 distributed over the entire surface of the inner wall 20, but the invention is not limited thereto. In some embodiments, the surface modifying coating 40 may be distributed only around the through-holes 210, that is, the surface of the inner wall 20 may be covered with the surface modifying coating 40 only in the region near the periphery of the through-holes 210. The surface modifying coating 40 helps to promote wettability (or hydrophilicity) of the inner wall 20, so that the liquid phase change heat storage material 30 flows between the receiving cavities 200 more easily through the through holes 210.

In this embodiment, the via 210 is filled with the phase change heat storage material. Furthermore, in the present embodiment using a solid-phase change liquid-phase heat storage material, the position of each through hole 210 on the inner wall 20 can be such that the through hole 210 is filled with the liquid-phase change heat storage material 30. For example, the paraffin is used as the phase change heat storage material 30, and the through holes 210 on the inner wall 20 may be filled with paraffin in solid and liquid states, as shown in fig. 2; alternatively, when the paraffin is in a solid state, at least a portion of the through-hole 210 is not filled with the paraffin in a solid state, and the through-hole 210 is completely filled once the paraffin expands in volume due to the paraffin becoming a liquid state. The proper positioning of the through holes 210 facilitates natural convection of the liquid phase change heat storage material 30.

In the present embodiment, the opening ratio of the inner wall 20 between two adjacent accommodating cavities 200 may be 10% to 20%. As shown in fig. 2, the area of the inner wall 20 between two adjacent accommodating cavities 200 is A1, the area of the through hole 210 on the inner wall 20 is A2, and the aperture ratio can be defined as: A2/A1; wherein the aperture ratio may satisfy the following condition: A2/A1 is more than or equal to 10% and less than or equal to 20%. The through holes 210 having an appropriate aperture ratio can help to provide stable natural convection to the liquid phase change heat storage material 30. In fig. 2, the area (A1) of the inner wall 20 is defined as the product of the width L1 of the inner wall 20 and the height L2 of the inner wall 20.

Further referring to FIG. 3, a schematic diagram of a portion of the phase change thermal management device of FIG. 2 is shown in an enlarged view. In the present embodiment using a solid phase change liquid phase heat storage material, the aperture of the through hole 210 may depend on the natural convection flow rate of the liquid phase change heat storage material 30, the viscosity of the liquid phase change heat storage material 30, and/or the radial dimension of the receiving cavity 200 connected to the through hole 210. The natural convection flow rate of the liquid phase change heat storage material 30 may be defined as the flow rate of the phase change heat storage material 30 before flowing through the through-hole 210, where the flow state of the phase change heat storage material 30 may be regarded as a laminar flow. As shown in fig. 3, the aperture of the through hole is D, the natural convection flow rate of the liquid phase change heat storage material is V, the viscosity of the liquid phase change heat storage material is V, and the radial dimension of the receiving cavity 200 connected to the through hole 210 is H, which satisfies the following conditions: d is less than or equal to (VH) ² ) And/2200 v. The through holes 210 with appropriate pore sizes can make the laminar phase change heat storage material 30 in any one of the accommodating cavities 200 flow to another accommodating cavity 200 through the through holes 210 and become turbulent flow, thereby helping to improve heat dissipation efficiency. In fig. 3, the radial dimension H of the receiving cavity 20 connected to the through hole 210 may be equal to the height L2 of the inner wall 20.

Also, in other embodiments using liquid-phase and gas-phase heat storage materials, the aperture of the through-hole 210 may depend on the natural convection flow rate of the gaseous phase change heat storage material 30, the viscosity of the gaseous phase change heat storage material 30, and/or the radial dimension of the receiving cavity 200 connected to the through-hole 210.

FIG. 4 is a schematic cross-sectional view of a phase change thermal management device according to another embodiment of the invention. In this embodiment, the phase change thermal management device 1b includes a housing 10, an inner wall 20b and a phase change heat storage material 30, wherein the inner wall 20b between two adjacent accommodating cavities 200 has a plurality of through holes 210b. The through holes 210b may have the same shape size or different shape sizes. The plurality of through holes 210b on different inner walls 20b may have the same arrangement or different arrangements. The opening ratio of the inner wall 20b between two adjacent receiving cavities 200 may be 10% to 20%. In detail, the area of the inner wall 20b is A1, and the total area of all the through holes 210b on the inner wall 20b is A2, the aperture ratio can be defined as: A2/A1. Wherein the aperture ratio may satisfy the following condition: A2/A1 is more than or equal to 10% and less than or equal to 20%.

Fig. 5a to 5b are schematic temperature distribution diagrams of a conventional temperature equalizing plate and a phase change thermal management device according to an embodiment of the invention. The temperature equalization plate model used herein comprises a closed shell and a plurality of inner walls positioned in the closed shell, wherein the inner walls are connected to form a plurality of closed accommodating cavities, that is to say, no through holes are formed on the inner walls in the temperature equalization plate model. Fig. 5a shows a temperature distribution of the heat source S after radiating the heat from the temperature equalization plate model for 1 hour, and fig. 5b shows a temperature distribution of the phase change thermal management device 1a of fig. 1 after radiating the heat from the same heat source S for 1 hour. As can be seen from fig. 5a, the temperature of the central region of the isopipe model, which is closer to the heat source S, is higher, and the temperature of the edge region, which is farther from the heat source S, is significantly lower, which means that the heat energy is concentrated in the central region and cannot be rapidly transferred to the edge region. In contrast, according to fig. 5b, although the temperature of the central region of the phase change thermal management device 1a near the heat source S is also relatively high, the temperature of the edge region far from the heat source S is less different from the temperature of the central region, and in addition, the low temperature region is less in comparison with the edge region far from the heat source S in fig. 5a, and these results represent that the thermal energy is transferred to the edge region more quickly in the case that the phase change thermal storage material is free-flowing through the through hole.

Fig. 6 is a schematic diagram of an electronic product with a phase change thermal management device according to another embodiment of the present invention. An electronic product, such as but not limited to a communication device, includes a base 2, an antenna 3, an amplifier 4, a thermal interface material 5, a heat sink 6, and the phase change thermal management device 1a of fig. 1. The antenna 3, the amplifier 4 and the thermal interface material 5 may be disposed on one side of the base 2, and the phase change thermal management device 1a and the heat sink 6 may be disposed on the other side of the base 2. The antenna 3 and the amplifier 4 are used as heat sources, and heat energy generated by the operation of the antenna and the amplifier can be transferred to the phase change thermal management device 1a through the thermal interface material 5. The phase change heat storage material in the phase change heat management device 1a absorbs heat energy to avoid the excessive temperature of the antenna 3 and the amplifier 4, and then discharges the heat energy to the outside through the heat sink 6. The heat sink 6 may be a fin or a thermally conductive copper sheet.

Fig. 7 is a schematic view of an electronic product with a phase change thermal management device according to still another embodiment of the present invention. Compared with the electronic product of fig. 6, the electronic product of fig. 7 further comprises a heat pipe 7 and a heat dissipation fan 8. The heat energy generated by the operation of the antenna 3 and the amplifier 4 can be sequentially transferred to the phase change thermal management device 1a through the thermal interface material 5 and the heat pipe 7. The heat energy absorbed by the phase change heat storage material of the phase change heat management device 1a can be discharged to the outside through the radiator 6 and the cooling fan 8.

In accordance with an embodiment of the present invention, grooves or bumps may be additionally formed around the through holes of the phase change thermal management device to facilitate increasing thermal uniformity. Fig. 8 to 10 are partial schematic views of a cavity of a thermal phase change management device according to an embodiment of the invention. Fig. 8 schematically illustrates a plurality of grooves 211 formed on the inner wall 20 and located around the through hole 210, and two adjacent grooves 211 are spaced at an angle of 90 degrees with respect to the center of the through hole 210. Fig. 9 schematically illustrates a plurality of grooves 211 formed on the inner wall 20 and located around the through hole 210, and two adjacent grooves 211 are spaced apart by 60 degrees with respect to the center of the through hole 210. Fig. 10 schematically illustrates a plurality of grooves 212 formed on the inner wall 20 and located around the through holes 210, wherein the width of each groove 212 gradually increases outwards.

In summary, according to the phase change thermal management device disclosed by the invention, the inner walls of the housing are connected to form a plurality of accommodating cavities for accommodating the phase change heat storage material, and the adjacent accommodating cavities are mutually communicated through the through holes on the inner walls. When the heat energy generated by the external heat source is transferred to the phase-change heat management device, the phase-change heat storage material can absorb the heat energy so as to achieve the purpose of controlling the temperature of the external heat source, and the phase-change heat storage material can flow into other adjacent accommodating cavities through the through holes. Therefore, if the phase-change heat storage materials in the other accommodating cavities have not been subjected to phase change, the phase-change heat storage materials which have absorbed heat and have undergone phase change transfer heat energy through flowing energy, so that the phase-change heat storage materials in the other accommodating cavities can absorb heat energy to undergo phase change. In addition, under the condition that the heat energy is intensively transferred to a specific area and the temperature of part of the accommodating cavity is high, the phase-change heat storage material which absorbs heat and changes phase can flow into the accommodating cavity with high temperature through the through hole, so that the distribution range of the phase-change heat storage material in the accommodating cavity with high temperature is increased, and the heat dissipation efficiency is improved.

Claims

1. A phase change thermal management device, comprising:

a housing having an interior space;

the inner walls are arranged in the inner space and are connected to form a plurality of accommodating cavities, and two adjacent accommodating cavities are communicated with each other through at least one through hole of one inner wall; and

the phase change heat storage material is positioned in at least part of the accommodating cavities.

2. The phase change thermal management device of claim 1, wherein the phase change thermal storage material is a solid phase change liquid phase thermal storage material.

3. The phase change thermal management device of claim 2, wherein the phase change thermal storage material comprises indium-bismuth-tin alloy, indium-gallium-tin alloy, paraffin, or a combination thereof.

4. The phase change thermal management device according to claim 1, wherein a trench or bump is disposed around the at least one via.

5. The phase change thermal management device of claim 1, further comprising a surface modifying coating disposed on the surfaces of the inner walls.

6. The phase change thermal management device of claim 1, further comprising a surface modifying coating disposed around the at least one via.

7. The phase change thermal management device according to claim 5 or 6, wherein the surface modifying coating comprises cobalt, nickel, molybdenum, titanium, or a combination thereof.

8. The phase change thermal management device of claim 1, wherein the inner walls comprise metal, plastic, polymer, or a combination thereof.

9. The phase change thermal management device of claim 1, further comprising a foamed metal added to the phase change thermal storage material.

10. The phase change thermal management device of claim 9, wherein the foaming metal is aluminum foaming metal, copper foaming metal or nickel foaming metal.

11. The phase change thermal management device of claim 1, wherein the opening ratio of the inner wall between two adjacent ones of the accommodating cavities is 10% to 20%.

12. The phase change thermal management device of claim 1, wherein the at least one via is filled with the phase change thermal storage material.

13. The phase change thermal management device of claim 1, wherein the at least one via is positioned on one of the inner walls such that the at least one via is filled with the phase change thermal storage material in a liquid state.

14. The phase change thermal management device of claim 1, wherein the aperture of the at least one via is dependent on at least one of:

the natural convection flow rate of the phase change heat storage material in liquid state,

viscosity of the phase change heat storage material in liquid state, and

the radial dimension of the accommodating cavity connected with the at least one through hole.

15. The phase change thermal management device of claim 14, wherein the at least one through hole has a pore diameter D, the natural convection flow rate of the phase change thermal storage material in liquid state is V, the viscosity of the phase change thermal storage material in liquid state is V, and the radial dimension of the receiving cavity connected to the at least one through hole is H, which satisfies the following condition:

D≤(VH ² )/2200ν。