TWI799036B - Phase change heat management device - Google Patents

Abstract

A phase change heat management device includes a casing, a plurality of inner walls and a phase change material. The casing defines an internal space. The inner walls are arranged in the internal space, and these inner walls cross one another to form a plurality of accommodation cells. Two adjacent accommodation cells are communicated with each other through at least one hole on the inner wall. The phase change material is located in at least part of the accommodation cells.

Description

Phase Change Thermal Management Device

The invention relates to a phase change thermal management device.

The heat dissipation of electronic products has long been a research goal in this technical field. Generally speaking, cooling fans and water cooling systems are generally considered to have better cooling efficiency. However, Internet communication equipment, satellite electronic components, and rechargeable batteries are mostly used outdoors or in space, and these environments lack power, so fans or water cooling systems cannot be used for heat dissipation, and only passive cooling methods such as natural convection or radiation can be relied on. To dissipate heat.

In recent years, phase change materials have been widely used in passive cooling elements, such as vapor chambers. A phase change material that is solid or liquid at room temperature can absorb heat energy generated by a heat source and transform into a liquid or gaseous state, thereby achieving the purpose of controlling the temperature of the heat source. .

The invention provides a phase change heat management device to increase heat dissipation and avoid overheating of components.

A phase change thermal management device disclosed in an embodiment of the present invention includes a casing, multiple inner walls and a phase change heat storage material. The casing has an inner space. The inner walls are arranged in the inner space, and these inner walls are connected to form a plurality of accommodating cavities. Two adjacent accommodating cavities communicate with each other through at least one through hole in one of the inner walls. The phase change heat storage material is located in at least part of the containing cavity.

According to the phase change heat management device disclosed in the present invention, 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 heat energy to achieve the purpose of controlling the temperature of the external heat source, and the phase change heat storage material can It flows into other adjacent accommodating cavities through the through hole. In this way, if the phase-change heat storage material in other accommodation cavities has not yet phase-transformed, the phase-change heat storage material that has absorbed heat and changed its phase can allow the phase-change heat storage material in other accommodation cavities to absorb heat energy by flowing A phase change occurs, thereby stabilizing the temperature of the external heat source. In addition, in the case where the heat energy is concentrated and transferred to a specific area, resulting in a higher temperature in some of the accommodating cavities, the phase-change heat storage material that has absorbed heat and undergoes a phase change can flow into the high-temperature accommodating cavity through the through holes, thereby Increase the amount of phase-change heat storage material in the high-temperature accommodating cavity, thereby improving heat dissipation efficiency.

The above description of the content of the present invention and the following description of the implementation are used to demonstrate and explain the principle of the present invention, and to provide further explanation of the patent application scope of the present invention.

1a, 1b: Phase change thermal management device

10: Shell

110: Internal space

20, 20b: inner wall

200: accommodating cavity

210, 210b: through holes

21: The first inner wall

22: Second inner wall

23: The third inner wall

24: The fourth inner wall

25: fifth inner wall

211, 212: Groove

30: Phase change heat storage materials

40: Surface modification coating

2: base

3: Antenna

4: Amplifier

5: thermal interface material

6: Radiator

7: heat pipe

8: cooling fan

L1: width

L2: Height

D: Aperture

V: natural convection velocity

H: radial dimension

S: heat source

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

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

FIG. 3 is a partially enlarged schematic diagram of the phase change thermal management device in FIG. 2 .

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

FIG. 5 is a simulated diagram of temperature distribution of a conventional vapor chamber 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 equipped 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 equipped with a phase change thermal management device according to yet another embodiment of the present invention.

FIG. 8 is a partial schematic diagram of the accommodating cavity of the phase change thermal management device according to an embodiment of the present invention.

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

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

The detailed features and advantages of the present invention are described in detail in the following embodiments, the content of which is sufficient to enable anyone familiar with the relevant art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in this specification, the scope of the patent application and the drawings , anyone skilled in the art can easily understand the purpose and advantages of the present invention. The following examples are to further describe the concept of the present invention in detail, but not to limit the scope of the present invention in any way.

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

The housing 10 is, for example but not limited to, a metal housing with a closed inner space 110 . There are multiple inner walls 20 disposed in the inner space 110 of the casing 10 , and these inner walls 20 are connected to form a plurality of accommodating cavities 200 . More specifically, the end of the inner wall 20 is connected to the inner surface of the housing 10, and the connection can be realized by integral forming or non-integral forming, wherein the non-integral forming means are, for example: buckle, clip fit, but not limited to. As shown in FIG. 1 , these inner walls 20 intersect with each other to form a network-like stent structure. 1 and 2 illustrate that a plurality of inner walls 20 are staggered to form a plurality of rectangular accommodation cavities 200 , but the shape of the accommodation cavities 200 is not limited thereto. The material of the inner wall 20 can be selected from the group consisting of metal, plastic, polymer and combinations thereof.

In these accommodating cavities 200 , an inner wall 20 is provided between any two adjacent accommodating cavities 200 , and the two adjacent accommodating cavities 200 communicate with each other via through holes 210 on the inner walls 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 The wall 22 is arranged in parallel with the third inner wall 23, the fourth inner wall 24 is arranged in parallel with the fifth inner wall 25, and the fourth inner wall 24 and the fifth inner wall 25 are respectively connected with the first inner wall 21 and the second inner wall 22. Interlaced with the third inner wall 23 to form an accommodating cavity 200 . Two adjacent accommodating cavities 200 communicate with each other through the through hole 210 of the second inner wall 22 . Similarly, any accommodating cavity 200 can be connected to the adjacent other through holes 210 of the first inner wall 21, the third inner wall 23, the fourth inner wall 24 or the fifth inner wall 25. He accommodates the cavities 200 to communicate with each other. The through-holes 210 on the inner wall 20 of three adjacent accommodating cavities 200 are centered on the same axis or on different axes. In addition, the opening sizes of the through-holes can be the same or different, so as to increase the fluid flow process. Turbulence effect to facilitate heat transfer. 1 and 2 show that the inner wall 20 between two adjacent accommodating cavities 200 has a single through hole 210 , but the number of the through holes 210 is not limited thereto.

The phase change heat storage material 30 is located in at least part of the accommodation cavity 200 . FIG. 1 and FIG. 2 show that there is a phase-change heat storage material 30 in each cavity 200 , but in other embodiments, there may be no phase-change heat storage material in some cavities.

The phase change heat storage material 30 may be a solid phase change liquid phase heat storage material or a liquid phase change gas phase heat storage material. The heat storage material 30 with a phase change from solid to liquid can be selected from the group consisting of indium bismuth tin alloy, indium gallium tin alloy, paraffin and combinations thereof. In addition, graphite or foamed metal (not shown) can be added to the phase change heat storage material 30 to improve the thermal conductivity of the phase change heat storage material 30 . Metal foams are, for example, aluminum metal foams, copper metal foams or nickel metal foams.

When heat energy generated by an external heat source (such as a high-power chip in a network communication device, not shown) is transferred to the phase change thermal management device 1a, the heat energy can pass through the casing 10, the inner wall 20 and then reach the phase change heat storage material in sequence. 30, and the phase change heat storage material 30 absorbs thermal energy during the phase change process to achieve the purpose of controlling the temperature of the external heat source. In this embodiment using a solid phase-change liquid-phase heat storage material, the phase-change heat storage material 30 after the phase change is in a liquid state, and at this time, the liquid phase-change heat storage material 30 in any cavity 200 can pass through the inner wall The through hole 210 on the 20 flows to other adjacent accommodating cavities 200 . If the phase change heat storage material 30 in the other accommodating cavities 200 is solid, The liquid phase change heat storage material 30 can allow the solid phase change heat storage material 30 to undergo a phase change to exert its function of absorbing heat energy. In addition, in the case where the heat energy is concentrated and transferred to a specific area, resulting in a higher temperature in part of the accommodating cavity 200, the liquid phase-change heat storage material 30 can flow into the high-temperature accommodating cavity 200 through the through hole 210 to increase the temperature of the accommodating cavity 200. The distribution range of the heat storage material 30 is phase-changed in the high-temperature accommodating cavity 200 , thereby improving heat dissipation efficiency.

In this embodiment, the phase change thermal management device 1 a may further include a surface modification coating 40 disposed on each surface of the inner wall 20 . The material of the surface modifying coating 40 can be cobalt, nickel, molybdenum, titanium, or a combination thereof. 1 and 2 illustrate that the surface modifying coating 40 is distributed on the entire surface of the inner wall 20 , but the invention is not limited thereto. In some embodiments, the surface modification coating 40 may only be distributed around the through hole 210 , that is to say, the surface of the inner wall 20 is covered with the surface modification coating 40 only near the area around the through hole 210 . The surface modification coating 40 helps to improve the wettability (or hydrophilicity) of the inner wall 20 , making it easier for the liquid phase change heat storage material 30 to flow between the accommodating cavities 200 through the through holes 210 .

In this embodiment, the through hole 210 is filled with the phase change heat storage material. Furthermore, in this embodiment using a solid-phase-change-liquid-phase heat storage material, the positions of the through holes 210 on the inner wall 20 allow the through holes 210 to be filled with the liquid phase change heat storage material 30 . Taking paraffin wax as an example for the phase change heat storage material 30, the through hole 210 on the inner wall 20 can be filled with paraffin wax in solid and liquid states, as shown in Figure 2; or, when the paraffin wax is in a solid state, through Hole 210 at least a part is not filled by solid paraffin and reveals, once paraffin becomes liquid and expands in volume The via 210 will be completely filled. The proper location of the through hole 210 facilitates the natural convection of the liquid phase change heat storage material 30 .

A2/A1

20%。具有適當開口率的通孔210能夠幫助讓液態相變化儲熱材料30具有穩定的自然對流。在圖2中，內壁20的面積(A1)被定義為內壁20之寬度L1與內壁20之高度L2的乘積。 In this embodiment, the opening ratio of the inner wall 20 between two adjacent accommodating cavities 200 may be 10% to 20%. As shown in Figure 2, the area of the inner wall 20 between two adjacent accommodating cavities 200 is A1, and the area of the through hole 210 on the inner wall 20 is A2, then the opening ratio can be defined as: A2/A1 ; Wherein, the opening ratio can meet the following conditions: 10%

A2/A1

20%. The through hole 210 with a proper opening ratio can help the liquid phase change heat storage material 30 to have a stable natural convection. 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 .

(VH²)/2200ν。適當孔徑大小的通孔210能夠讓任一容置空腔200中的層流相變化儲熱材料30經過通孔210流動到另一容置空腔200後變成紊流，而有助於提升散熱效率。 在圖3中，與通孔210相連的容置空腔20的徑向尺寸H可等於內壁20之高度L2。 Further referring to FIG. 3 , it is a partially enlarged schematic diagram of the phase change thermal management device in FIG. 2 . In this embodiment using a solid phase change liquid heat storage material, the diameter 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 connection with the through hole 210. The radial dimension of the accommodation cavity 200 connected with the holes 210 . The natural convection flow rate of the liquid phase-change heat storage material 30 can be defined as the flow rate before the phase-change heat storage material 30 flows through the through hole 210 , and the flow state of the phase-change heat storage material 30 can be regarded as a laminar flow. As shown in Figure 3, the diameter of the through hole is D, the natural convection velocity of the liquid phase change heat storage material is V, the viscosity of the liquid phase change heat storage material is ν, and the diameter of the accommodation cavity 200 connected to the through hole 210 is The dimension is H, which satisfies the following conditions: D

(VH ² )/2200ν. The through holes 210 with appropriate pore size can make the laminar flow phase change heat storage material 30 in any accommodating cavity 200 flow through the through holes 210 to another accommodating cavity 200 and become turbulent flow, which helps to improve heat dissipation efficiency. In FIG. 3 , the radial dimension H of the accommodating 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-change gas-phase heat storage materials, the diameter 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 accommodating cavity 200 connected with the through hole 210 .

A2/A1

20%。 4 is a schematic cross-sectional view of a phase change thermal management device according to another embodiment of the present 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. hole 210b. The through holes 210b may have the same shape and size or different shape and size. The multiple through holes 210b on different inner walls 20b may have the same arrangement or different arrangements. The opening ratio of the inner wall 20 b between two adjacent accommodating cavities 200 may be 10% to 20%. In detail, the area of the inner wall 20b is A1, the total area of all the through holes 210b on the inner wall 20b is A2, and the opening ratio can be defined as: A2/A1. Wherein, the aperture ratio can meet the following conditions: 10%

A2/A1

20%.

FIG. 5 is a simulated diagram of temperature distribution of a conventional vapor chamber and a phase change thermal management device according to an embodiment of the present invention. The temperature chamber model used here includes an airtight shell and multiple inner walls located in the airtight shell, and the inner walls are connected to form a plurality of closed accommodation cavities, that is to say, the inner walls of the chamber No through hole is formed in the wall. Figure 5(a) shows the temperature distribution after the vapor chamber model dissipates the heat source S for 1 hour, and Figure 5(b) shows the phase change thermal management device 1a in Figure 1 dissipating the same heat source S for 1 hour Temperature distribution after hours. It can be seen from Figure 5(a) that the temperature in the central area closer to the heat source S in the vapor chamber model is higher, and the temperature in the edge area farther from the heat source S is significantly lower, which means that heat energy is concentrated in the central area and cannot be transferred quickly to the edge area. Relatively according to Fig. 5(b), although the temperature of the central region near the heat source S in the phase change thermal management device 1a is relatively high, the temperature difference between the edge region far away from the heat source S and the temperature of the central region is small. In addition, compared with Fig. 5 (a) There are fewer low-temperature regions in the edge area away from the heat S. These results all indicate that the heat energy is transferred to the edge area faster when the through-holes provide the free flow of the phase-change heat storage material.

FIG. 6 is a schematic diagram of an electronic product equipped with a phase change thermal management device according to another embodiment of the present invention. The electronic product is, for example but not limited to, communication equipment, which 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 1 a of FIG. 1 . The antenna 3 , the amplifier 4 and the thermal interface material 5 can be disposed on one side of the base 2 , and the phase change thermal management device 1 a and the heat sink 6 are disposed on the other side of the base 2 . The antenna 3 and the amplifier 4 are used as heat sources, and the heat energy generated by their operation can be transferred to the phase change thermal management device 1 a through the thermal interface material 5 . The phase change heat storage material in the phase change thermal management device 1 a absorbs heat energy to prevent the antenna 3 and the amplifier 4 from overheating, and then discharges the heat energy to the outside through the radiator 6 . The heat sink 6 can be a fin or a heat conducting copper sheet.

FIG. 7 is a schematic diagram of an electronic product equipped with a phase change thermal management device according to yet another embodiment of the present invention. Compared with the electronic product shown in FIG. 6 , the electronic product shown in FIG. 7 further includes a heat pipe 7 and a cooling fan 8 . The heat energy generated by the operation of the antenna 3 and the amplifier 4 can be transferred to the corresponding phase through the thermal interface material 5 and the heat pipe 7 in sequence. Change thermal management device 1a. The heat energy absorbed by the phase change heat storage material of the phase change thermal management device 1 a can be discharged to the outside through the radiator 6 and the cooling fan 8 .

According to an embodiment of the present invention, grooves may be additionally formed around the through holes of the phase change thermal management device to facilitate thermal uniformity. Please refer to FIG. 8 to FIG. 10 , which are partial schematic views of the accommodating cavity of the phase change thermal management device according to an embodiment of the present invention. FIG. 8 exemplarily shows that a plurality of grooves 211 are 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 relative to the center of the through hole 210 . FIG. 9 exemplarily shows that a plurality of grooves 211 are formed on the inner wall 20 and located around the through hole 210 , and two adjacent grooves 211 are spaced at an angle of 60 degrees relative to the center of the through hole 210 . FIG. 10 exemplarily shows that a plurality of grooves 212 are formed on the inner wall 20 and located around the through hole 210 , wherein the width of each groove 212 gradually increases outward. The grooves in FIGS. 8 to 10 are not intended to limit the present invention. In other embodiments, bumps may be formed around the through holes to increase thermal uniformity.

To sum up, according to the phase change thermal management device disclosed in the present invention, the inner walls of the housing are connected to form a plurality of storage cavities for accommodating phase change heat storage materials, and the adjacent storage cavities pass through the inner walls. The through holes on the wall communicate with each other. When the heat energy generated by the external heat source is transferred to the phase change thermal management device, the phase change heat storage material can absorb heat energy to achieve the purpose of controlling the temperature of the external heat source, and the phase change heat storage material can flow to other adjacent accommodation through the through hole cavity. In this way, if the phase-change heat storage material in other accommodation cavities has not yet phase-transformed, the phase-change heat storage material that has absorbed heat and has phase-changed transfers heat energy through flow energy to make the phase-change heat storage in other accommodation cavities A material can undergo a phase change by absorbing thermal energy. In addition, when the heat energy is more concentrated and transferred to a specific area, resulting in In the case where the temperature of some accommodation cavities is relatively high, the phase-change heat storage material that has absorbed heat and undergoes a phase change can flow into the high-temperature accommodation cavity through the through hole, so as to increase the number of phase-change heat storage materials in the high-temperature accommodation cavity. distribution range to improve heat dissipation efficiency

Although the disclosure of the embodiments of the present invention is as described above, it is not intended to limit the present invention. Anyone who is familiar with the related art can use the shapes, structures, and features described in the application scope of the present invention without departing from the spirit and scope of the present invention. Slight changes can be made in the spirit and spirit, so the scope of patent protection of the present invention must be defined in the scope of patent application attached to this specification.

1a: Phase change thermal management device

10: shell

110: Internal space

20: inner wall

200: accommodating cavity

210: through hole

21: The first inner wall

22: Second inner wall

23: The third inner wall

24: The fourth inner wall

25: fifth inner wall

30: Phase change heat storage materials

Claims (15)

A phase change thermal management device, comprising: a housing with an inner space; a plurality of inner walls arranged in the inner space, the inner walls are connected to form a plurality of accommodation cavities, and the accommodation Two adjacent cavities communicate with each other through at least one through hole in one of the inner walls; and a phase change heat storage material is located in at least part of the accommodating cavities. The phase change heat management device as claimed in claim 1, wherein the phase change heat storage material is a solid phase change liquid heat storage material. The phase change thermal management device as claimed in item 2, wherein the phase change heat storage material comprises indium-bismuth-tin alloy, indium-gallium-tin alloy, paraffin, or a combination thereof. The phase change thermal management device as claimed in claim 1, wherein a groove is arranged around the at least one through hole. The phase change thermal management device as claimed in Claim 1 further includes a surface modification coating disposed on the surfaces of the inner walls. The phase change thermal management device as claimed in claim 1 further comprises a surface modification coating distributed around the at least one through hole. The phase change thermal management device according to claim 5 or 6, wherein the material of the surface modification coating includes cobalt, nickel, molybdenum, titanium, or a combination thereof. The phase change thermal management device according to claim 1, wherein the inner walls are made of metal, plastic, polymer, or a combination thereof. The phase change thermal management device as claimed in Claim 1 further includes a metal foam added to the phase change heat storage material. According to the phase change heat management device described in Claim 9, the metal foam can be aluminum foam metal, copper foam metal or nickel foam metal. The phase change thermal management device as claimed in claim 1, wherein the opening ratio of the inner wall between adjacent two of the accommodating cavities is 10% to 20%. The phase change heat management device as claimed in claim 1, wherein the at least one through hole is filled with the phase change heat storage material. The phase change thermal management device as claimed in claim 1, wherein the position of the at least one through hole on one of the inner walls is suitable for filling the at least one through hole with the liquid phase change heat storage material. The phase change thermal management device as claimed in claim 1, wherein the diameter of the at least one through hole depends on at least one of the following: the natural convection flow rate of the liquid phase change heat storage material, the liquid phase change heat storage material Viscosity, and the radial dimension of the accommodating cavity connected with the at least one through hole. The phase change heat management device as described in Claim 14, wherein the diameter of the at least one through hole is D, the natural convection velocity of the liquid phase change heat storage material is V, and the viscosity of the liquid phase change heat storage material is ν , the radial dimension of the accommodating cavity connected to the at least one through hole is H, which satisfies the following conditions: D

(VH ² )/2200ν.

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