TW201818042A - Heat dissipation device used in loop heat pipe and manufacturing method of housing thereof heat can be collected at single location of the housing, without causing the temperature raise at other portions inside the housing, so a working fluid can perform a heat dissipation operation at a normal temperature - Google Patents

Abstract

The present invention relates to a heat dissipation device used in loop heat pipe and a manufacturing method of housing thereof. The heat dissipation device is manufactured using a composite sheet element as a manufacturing material, wherein the composite sheet element is fabricated by means of composite rolling. The housing of the heat dissipation device includes an inner housing and an outer housing made of two materials having different heat conductivities. The inner housing is formed with a heat conductive opening, and a capillary element is disposed in the heat conductive opening and connected to the outer housing. A heating element is adhered on the housing of the heat dissipation device, and heat is not easily transferred from the outer housing to the inner housing due to the different heat conductivities. The heat of the outer housing is collected and transferred to a portion of the outer housing defined at a location where the capillary element is connected to another capillary element. As such, the heat can be collected at single location of the housing, without causing the temperature raise at other portions inside the housing. Accordingly, a working fluid can perform a heat dissipation operation at a normal temperature.

Description

Heat dissipating device applied to loop heat pipe and manufacturing method of casing thereof

The invention relates to a heat dissipation device, in particular to a heat dissipation device of a loop heat pipe.

With the rapid development of technology, there are many electronic devices in order to achieve high-power use, so most electronic devices require high power to operate, and after a long time of use, electronic devices will generate a large amount of heat, resulting in the temperature of the electronic device itself When the temperature rises, it will damage the parts of the electronic device or affect the working efficiency of the electronic device. Therefore, how to efficiently dissipate electronic devices has been one of the long-standing problems in the high-tech industry.

As mentioned above, among the various components of the phase-change thermal conduction elements, such as heat pipes, thermal syphons, and Vapor chambers, the traditional passive heat transfer elements are mature, but The transmission distance, heat transfer efficiency, and volume are limited. They can only be used in computers or personal communication products, such as smart phones and tablet computers. If long-distance heat transfer applications are considered, such as data center database computer server cabinets, water-cooled liquids must be used for heat dissipation. However, the water cooling system needs pump energy to circulate the water cooling liquid in the heat dissipation pipeline, adding extra hardware and electricity costs.

Therefore, the heat dissipation technology related to electronic devices in recent years uses a loop heat pipe (LHP) for heat dissipation. As for the loop heat pipe (LHP), it is a closed loop pipe that uses micron-sized porous capillary elements to achieve high power heat conduction. The working fluid is filled in the loop heat pipe, and the working fluid will be exchanged between the evaporator and the condenser to achieve heat transfer. That is, the heat of a heating source (such as an electronic device) is transferred from the evaporator to the working fluid, so that the working fluid becomes a gas. As the gas flows through the condenser, it is condensed into a working fluid. The micron-sized porous capillary element inside the evaporator can use the capillary force to absorb the working fluid, and once again receive the thermal energy released by the heat source attached to the outer surface of the evaporator. The working fluid becomes gas again. The heat is repeatedly circulated in the manner described above. That is, the working body is switched back and forth between the phases to achieve the effect of thermal diffusion, thereby reducing the temperature of the electronic device.

In the conventional technology, in the above-mentioned loop heat pipe (LHP), because the evaporator and the liquid storage space are too close in structure, when the heat source is attached to the evaporator, the heat source transmits heat energy to the evaporator, and at the same time It will also be transmitted to the working fluid in the liquid storage space. This will cause the temperature of the working fluid to rise at the same time, which will cause the working fluid to pass through the evaporator and take away the heat energy transmitted from the heat source to the evaporator. Not much heat can be taken away. As a result, the heat dissipation effect of the loop heat pipe is not good. Therefore, the present invention aims to improve the disadvantages of the conventional technology, and proposes a heat dissipation device for a loop heat pipe.

An object of the present invention is to provide a heat dissipation device applied to a loop heat pipe, which can cause the heat energy of the heat source to be directed to a specific area of the housing when the heat source is attached to the housing.

An object of the present invention is to provide a heat dissipation device applied to a loop heat pipe, which can improve the structural strength of the casing.

The invention provides a heat dissipation device applied to a loop heat pipe, which comprises a casing and a capillary element. The shell includes an outer shell and an inner shell. The outer shell covers the inner shell and forms an accommodating space inside the shell. The inner shell includes a thermally conductive opening located in the accommodating space and the outer shell. In the meantime, the thermal conductivity of the outer shell is higher than the thermal conductivity of the inner shell; and the capillary element is disposed at the thermally conductive opening and is connected to the shell, the capillary element has a plurality of channels. A heat source is attached to the outer shell, and heat is not easily conducted from the outer shell to the inner shell. The heat is collectively conducted from the casing to the casing where the capillary element and the capillary element are connected, without affecting the temperature of the working fluid stored in the interior, so it does not affect the cooling and circulating effect of the working fluid.

In order to have a further understanding and understanding of the features of the present invention and the effects achieved, we would like to provide a better embodiment and a detailed description with the following description:

Please refer to the first figure, which is a perspective view of a heat dissipation device applied to a loop heat pipe according to the present invention. As shown in the figure, this embodiment is a heat dissipation device 10 of a loop heat pipe 1, which serves as a heat dissipation structure for cooling a heat source. The heat source can be various electronic parts or devices that generate heat energy, and these electronic devices can be a central processing unit (CPU), a graphics processing unit (GPU), and a thermoelectric generator; TEG) and other electronic components. The heat dissipating device of the loop heat pipe in this embodiment enables the heat source emitted by the electronic device to be directed in one place, and the concentrated heat source provides the heat dissipating device as a place for conducting heat and heat.

Please refer to FIG. 2A, FIG. 2B, and FIG. 3 together, which are schematic cross-sectional views of the heat dissipation device applied to the loop heat pipe of the present invention, and enlarged view and exploded view of the area A of the second A. As shown in the figure, in this embodiment, the heat sink 10 of the loop heat pipe 1 includes a housing 11 and a capillary element 13. The casing 11 includes an outer casing 111 and an inner casing 113. The outer shell 111 covers the inner shell 113 and forms an accommodating space 100 inside the housing 11. The inner shell 113 includes a heat conducting opening 1131 located between the accommodating space 100 and the outer shell 111. The thermal conductivity of the outer shell 111 is higher than that of the inner shell 113. The material combination of the outer shell 111 and the inner shell 113 (a combination of high thermal conductivity and low thermal conductivity) includes copper and stainless steel, aluminum and stainless steel, Titanium and copper, copper and polytetrafluoroethylene, aluminum and polytetrafluoroethylene, and the combination of copper and polyether ether copper. The capillary element 13 is located in the accommodating space 100, is disposed in the heat conducting opening 1131, and is connected to the casing 111. Preferably, an outer peripheral wall of the capillary element 13 is attached to the casing 111. The capillary element 13 partitions the accommodation space 100 and is divided into an evaporation portion 115 and a liquid storage portion 117. The capillary element 13 further has a plurality of channels 130, and one channel opening 131 of each of the channels 130 corresponds to the evaporation portion 115. The capillary element 13 is made of porous polytetrafluoroethylene (PTFE) or sintered copper powder.

Furthermore, the loop heat pipe 1 further includes a circulation pipe 15. The circulation pipeline 15 includes a liquid pipeline 151, a condensation pipeline 153, and a gas pipeline 155. One end of the gas pipeline 155 is connected to the evaporation portion 115, and the other end thereof is communicated to one end of the condensation pipeline 153. The other end of the condensing pipe 153 is connected to one end of the liquid pipe 151, and the other end of the liquid pipe 151 is connected to the liquid storage section 117. In addition, a condensation element 17 is further included, which is disposed around the condensation pipe 153. The condensing element 17 is a heat dissipation fin or any heat dissipation structure, and its purpose is to cool and cool the fluid passing through the condensing pipe 153.

In this embodiment, the loop heat pipe 1 is a combination of the heat dissipation device 10 and the circulation pipe 15. A working fluid 19 is passed into the loop heat pipe 1, and the working fluid 19 is in the loop heat pipe 1. It is circulated internally, and is circulated in the liquid radiating device 10 and the circulation pipeline 15 in a liquid or gaseous manner. The working fluid 19 includes acetone, water, ethanol, ammonia or tetrafluoroethane.

Please refer to FIG. 4A and FIG. 4B together, which are schematic diagrams of using the loop heat pipe of the present invention and schematic diagrams of using the heat dissipation device applied to the loop heat pipe. As shown in the figure, in this embodiment, an electronic device 2 is placed on the heat sink 10 of the loop heat pipe 1. When the electronic device 2 is operated for a period of time, the electronic device 2 generates heat, which increases the temperature of the device itself. The electronic device 2 transfers heat to the casing 11 of the heat sink 10 in a thermally conductive manner. The shell 11 includes the outer shell 111 and the inner shell 113. The outer shell 111 and the inner shell 113 have different thermal conductivity coefficients. The outer shell 111 has a higher thermal conductivity coefficient than the inner shell 113.

In this embodiment, the material of the outer shell 111 is copper (the thermal conductivity is about 401 W / (m × K)), and the material of the inner shell 113 is stainless steel (the thermal conductivity is about 17 W / (m × K)). The material of the casing 11 is a copper / stainless steel composite plate. In this way, after the heat of the electronic device 2 is conducted to the outer casing 111, the thermal conductivity coefficient of the outer casing 111 and the inner casing 113 is greatly different. It is difficult for the outer casing 111 to transfer heat to the inner casing 113. At this time, the heat of the casing 111 is transferred to the part where heat is more easily transmitted, because the thermal conductivity coefficient of the capillary element 13 is close to or greater than the thermal conductivity coefficient of the casing 111, so the heat starts to guide the capillary element 13 connected to the casing 111. Parts. Most of the working fluid 19 is stored in the liquid storage portion 117 in a liquid form, and the capillary element 13 adsorbs part of the working fluid 19 in a liquid state. When the casing 111 introduces heat into the capillary element 13, the temperature of the capillary element 13 rises, and after the liquid working fluid 19 stored in the capillary element 13 absorbs enough heat, it gradually evaporates to form a gaseous state. Working fluid 19. The working fluid 19 in a gaseous state flows outward from the channel opening 131 of each of the channels 130 of the capillary element 13 to the evaporation portion 115.

Furthermore, the working fluid 19 in a gaseous state moves from the evaporation part 115 to the gas pipeline 155 and enters the condensing pipe 153 in a favorable manner, and the temperature of the working fluid 19 in a gaseous state after a long distance movement will It is in equilibrium with the temperature of the surrounding environment (that is, the wall of the circulating heat pipe 15). In this embodiment, the condensing element 17 is provided around the outer pipe wall of the condensing pipe 153, and the condensing element 17 is used for the condensing pipe 153 to dissipate heat, so that the temperature of the wall of the condensing pipe 153 is reduced. When the working fluid 19 in the gaseous state passes the condensing pipe 153, because the temperature of the working fluid 19 in the gaseous state is higher than the temperature of the wall of the condensing pipe 153, the temperature of the working fluid 19 and the condensing pipe The temperature of the pipe wall of 153 is thermally balanced by temperature. The temperature of the working fluid 19 in a gaseous state will gradually decrease, and gradually condense into the working fluid 19 in a liquid state.

After the working fluid 19 is condensed into a liquid state, it will continue to flow to the liquid pipeline 151, and the liquid state of the working fluid 19 will flow to the liquid storage portion 117 of the heat sink 11 to make the liquid state The working fluid 19 is collected in the liquid storage portion 117. The capillary element 17 absorbs the working fluid 19 in a liquid state until the liquid content of the capillary element 17 becomes saturated. In this case, the previous steps are repeated again, that is, the casing 111 conducts heat to the capillary element 13 so that the working fluid 19 stored in the capillary element 13 is again absorbed because it has absorbed enough thermal energy to raise its temperature. Evaporation repeats the circulating flow of the working fluid 19 again.

In the conventional technology, since the heat sink of the loop heat pipe has an evaporation chamber and a liquid storage chamber, when the heat source is attached to the heat sink, the heat source conducts heat to the entire heat sink, and the temperature of the whole heat sink rises. At the same time, the temperature of the evaporation chamber and the liquid storage chamber will also rise, and the relative temperature of the working fluid in the liquid storage chamber will also rise. In this way, the temperature of the working fluid itself is high, and it immediately evaporates after it absorbs not much thermal energy, and the working fluid can not absorb much thermal energy, which results in a poor heat dissipation effect of the loop heat pipe. Therefore, the present invention provides a heat dissipation device 10 for a loop heat pipe 1, which includes the casing 11 and the capillary element 13. The casing 11 is composed of two kinds of the outer shell 111 and the inner shell 113 with different thermal conductivity coefficients. The thermal conductivity coefficients of the outer casing 111 and the inner casing 113 are different, which makes it difficult for heat to be conducted from the outer casing 111 to the inner casing 113. The thermal conductivity of the capillary element 13 is greater than or similar to that of the casing 111, so that the heat of the heat source is conducted from the casing 111 to the capillary element 13, and a large amount of heat is connected to the capillary element 13 and the capillary element 13. Part of the casing 111 is concentrated at the place without affecting the temperature of the liquid storage portion 115 and the liquid working fluid 19 stored therein. After the working fluid 19 is adsorbed by the capillary element 13, the working fluid 19 absorbs thermal energy and evaporates. The working fluid 19 is circulated and radiated in a two-phase change (ie, liquid and gas) in the loop heat pipe 1.

Please also refer to the fifth figure, which is a flowchart of manufacturing the casing of the present invention. As shown in the figure, this embodiment illustrates the manufacturing method of the casing 11. In the first step S1: a first material and a second material are taken, and the thermal conductivity of the first material is greater than the thermal conductivity of the second material. The material combination of the first material and the second material includes copper and stainless steel, aluminum and stainless steel, titanium and copper, copper and polytetrafluoroethylene, aluminum and polytetrafluoroethylene, and copper and polyether ether copper. In this way, it is made through two materials with different thermal conductivity coefficients to change the heat conduction speed.

In the second step S3, the first material and the second material are rolled into a composite plate by composite rolling. The first material and the second material are respectively subjected to surface treatment and heating, and then the first material and the second material are superimposed on each other, that is, the two materials are directly pressed to be consolidated by external pressure. .

In the third step S5, a part of the composite material is processed to remove the second material. That is, the heat conductive opening 1131 is dug in the second material, and the first material can be directly seen through the heat conductive opening 1131. The thermally conductive opening 1131 is located in the middle of the second material in the shape of a sheet or a ring. This embodiment does not limit the structural size of the thermally conductive opening 1131 and the location of the second material, which can be performed according to user needs. Provided, and the purpose of the thermally conductive opening 1131 is to place the electronic device 2 on the surface of the casing 111 outside the thermally conductive opening 1131, so that the thermal energy of the electronic device 2 is concentratedly transmitted here, and then directly connected to the casing through The capillary element 13 of 11 performs heat dissipation.

In a fourth step S7: bending the composite plate, using the first material as the outer side and the second material as the inner side, to form a shell.

In this embodiment, two kinds of materials with different thermal conductivity are produced, and a composite rolling technology is used in the production, and thus a composite sheet is combined by this technology.

To sum up, the heat dissipation device of the loop heat pipe of the present invention includes a casing and a capillary element. The shell includes an outer shell and an inner shell, and the outer shell covers the inner shell, and the shell forms a containing space. The inner shell contains a thermally conductive opening located between the containing space and the outer shell. The thermal conductivity of the outer shell is higher than the thermal conductivity of the inner shell. . The capillary element is located in the accommodating space and is disposed in the housing. The accommodating space separated by the capillary element is an evaporation part and a liquid storage part. The heat source is affixed to the outer shell, and the heat source conducts heat to the outer shell, and the thermal conductivity coefficient between the outer shell and the inner shell is different, and heat is not easily conducted to the inner shell. In addition, the thermal conductivity of the capillary element is greater than or equal to the outer shell. The heat is directed to the capillary element, so that the temperature of the capillary element is higher, and the effect of heat concentration is achieved. In this way, the heat of the heat source has a low influence on the temperature of the liquid storage portion and the working fluid inside it, so that its temperature is lower than that of the capillary element. When the working fluid circulates, the temperature of the working fluid is lower than that of the capillary element, and the temperature of the working fluid must rise to the evaporation temperature to absorb more heat energy, so as to provide better heat dissipation efficiency. Furthermore, the present invention is based on the technology of composite rolling, so that different materials can be combined into a composite sheet. In addition to facilitating the manufacturing of the housing of the heat sink of the present invention. In addition, the shells of the two material processes have high compressive strength, and increase the operable temperature range of the loop heat pipe.

In summary, it only describes the implementation or examples of the technical means adopted by the present invention to solve the problem, and is not intended to limit the scope of patent implementation of the present invention. That is, all changes and modifications that are consistent with the meaning of the scope of patent application of the present invention, or made according to the scope of patent of the present invention, are covered by the scope of patent of the present invention.

1‧‧‧loop heat pipe

10‧‧‧Cooling device

100‧‧‧ accommodation space

11‧‧‧shell

111‧‧‧shell

113‧‧‧Inner shell

1131‧‧‧Conductive opening

115‧‧‧Evaporation Department

117‧‧‧Liquid storage department

13‧‧‧ Capillary element

130‧‧‧channel

131‧‧‧ entrance

15‧‧‧Circulation pipeline

151‧‧‧Liquid pipeline

153‧‧‧Condensing pipeline

155‧‧‧Gas pipeline

17‧‧‧Condensing element

19‧‧‧working fluid

The first figure: it is a perspective view of the heat dissipation device applied to the loop heat pipe according to the present invention; the second figure A: it is a schematic cross-sectional view of the heat dissipation device applied to the loop heat pipe according to the present invention; the second B: it is the second Enlarged view of area A in Fig. A; Fig. 3: It is an exploded view of the heat dissipation device applied to the loop heat pipe of the present invention; Fig. 4 A: It is a schematic view of the use of the loop heat pipe of the present invention; It is a schematic diagram of the use of the heat dissipation device applied to the loop heat pipe according to the present invention; and the fifth figure: it is a manufacturing flow chart of the heat dissipation device applied to the loop heat pipe according to the present invention.

Claims (10)

A heat dissipating device applied to a loop heat pipe, comprising: a shell including an outer shell and an inner shell, the outer shell covering the inner shell and forming an accommodating space, the inner shell including a heat conducting opening, and the outer shell And a capillary element, which is disposed on the thermally conductive opening and is connected to the shell, the capillary element has a plurality of channels. The heat dissipating device applied to a loop heat pipe as described in item 1 of the scope of patent application, wherein the material combination of the outer shell and the inner shell comprises copper and stainless steel, aluminum and stainless steel, titanium and copper, copper and polytetrafluoroethylene, aluminum and Teflon and copper and polyether ether copper. The heat dissipation device applied to a loop heat pipe as described in item 1 of the scope of the patent application, wherein the capillary element is made of porous polytetrafluoroethylene (PTFE) or copper powder is sintered. The heat dissipating device applied to a loop heat pipe according to item 1 of the scope of the patent application, wherein the accommodating space in the casing is separated by the capillary element into a liquid storage portion and an evaporation portion. As described in item 4 of the scope of the patent application, the heat dissipating device applied to a loop heat pipe further includes a circulation pipe, which includes a liquid pipe, a condensation pipe, and a gas pipe. One end is connected to the evaporation section, the other end is connected to one end of the condensation pipe, the other end of the condensation pipe is connected to one end of the liquid pipe, and the other end of the liquid pipe is connected to the liquid storage section. As described in item 5 of the scope of patent application, the heat dissipation device applied to a loop heat pipe further includes a condensing element disposed on the condensing pipe. A method for manufacturing a housing of a heat dissipation device, the steps include: taking a first material and a second material, wherein a thermal conductivity coefficient of the first material is greater than a thermal conductivity coefficient of the second material; and rolling the first material and the first material in a composite manner. The two materials are formed into a composite plate; the second material is processed to remove a part of the composite plate; and the composite plate is bent and processed with the first material as the outer side and the second material as the inner side to form a shell. According to the method for manufacturing a housing of a heat sink according to item 7 of the scope of the patent application, before the step of compositely rolling the first material and the second material into a composite plate, the first material and the second material are separately separated. After surface treatment and heating, the first material and the second material are superposed on each other. The method for manufacturing a housing of a heat sink according to item 7 of the scope of patent application, wherein the material combination of the first material and the second material includes copper and stainless steel, aluminum and stainless steel, titanium and copper, copper and polytetrafluoroethylene , Aluminum and polytetrafluoroethylene, and copper and polyether ether copper. According to the manufacturing method of the casing of the heat dissipation device described in item 7 of the scope of the patent application, in the step of processing and removing part of the composite material of the second material, part of the second material is located in the middle of the second material Flaky part or middle ring part.