JP2010025407A - Heat pipe container and heat pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat transport capacity of a heat pipe, in particular, of a flat heat pipe. <P>SOLUTION: In this heat pipe 6, an inner space 25 of an intermediate portion 22 formed between an evaporation portion 21 and a condensation portion 23 formed at both ends of a flat heat pipe container 7 is divided into a plurality of hollow portions 4 by partition walls 3 in the longitudinal direction of the heat pipe container 7. A plurality of filament bodies 5 are inserted to at least one of the hollow portions 4, and the filament bodies 5 are not inserted to at least one of the hollow portions 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat pipe that transports heat as latent heat of vaporization of a working fluid.

  Conventionally, heat pipes that transport heat are widely used as latent heat of working fluids. This type of heat pipe, after degassing from the inside of a sealed container, encloses a condensable fluid such as water, evaporates the working fluid by heat input from the outside, and condenses the vapor at low temperature and low pressure. It is a heat conducting element configured to transport heat as latent heat of the working fluid by flowing to the part and then radiating and condensing. Therefore, in order to transport heat as latent heat of the working fluid, the heat pipe has a heat transport capacity of several tens to one hundred and several tens of times the heat transport amount by copper, which is said to have the highest thermal conductivity. Yes.

  In the heat pipe, heat is transported by the evaporated working fluid flowing to the condensing part on the low temperature / low pressure side. However, it is necessary to return the condensed working fluid to the evaporation section (heat input section) after the heat transport, and conventionally, the action for the return is performed by utilizing the capillary pressure generated by the wick. Yes.

  As an example of a general structure of the wick in such a heat pipe, there is a narrow groove formed on the inner surface of the heat pipe container (see Patent Document 2), and the narrow groove is formed by etching, cutting, or the like. Are formed along the axial direction. A capillary pressure for reflux can be generated by this type of groove, and the narrow groove forms a flow path for the liquid phase working fluid.

  Other examples of the wick include a sintered wick formed by sintering copper powder on the inner wall of a heat pipe container, and a wire mesh wick in which a predetermined metal is formed in a so-called mesh shape (see Patent Document 2). ), A wire wick formed by pressing the linear body against the inner wall of the heat pipe container with a spiral wick gripping member.

  When a heat pipe provided with a wick having the above structure is used in an electronic device, the electronic component attached to the electronic device can be efficiently cooled or radiated.

  Incidentally, some of the above-mentioned heat pipes are deformed into a flat shape. In this flat heat pipe, the heat pipe container is crushed into a flat shape. Therefore, the heat pipe can be thinned relatively easily. Such a flat heat pipe can efficiently cool or dissipate electronic components even in an electronic device such as a personal computer in which it is difficult to provide a space in the height direction inside the housing.

  However, when the heat pipe container is formed to a predetermined thickness, the space inside the container is also narrowed. In a flat heat pipe or the like provided with the wire wick, a linear body is pressed against the inner wall of the heat pipe container by the elastic force of the wick gripping member to form a capillary pressure. Therefore, in order to secure the elastic force, the wick gripping member needs to be set to a predetermined size, so that the inside of the container is narrowed by the gripping member. As a result, there is a possibility that the steam passage is not sufficiently formed inside the container.

  As an example of a flat heat pipe that solves the above inconvenience, there is a flat heat pipe that is inserted into a thin container in a state in which the filaments are bound (see Patent Document 1). With a heat pipe having such a structure, capillary pressure is generated in the gap formed between the filaments, and the internal liquid phase working fluid can be refluxed. Therefore, there is no need to provide a wick gripping member inside the heat pipe container and press the filaments against the container inner wall, so that the mounting bracket can be omitted. As a result, the container is not easily deformed, and a steam passage formed inside the container is sufficiently secured, so that heat can be efficiently transported.

JP 2004-53186 A JP 2006-17355 A

  However, in the heat pipe having the structure in which the bundled striated body is inserted as described above, when the container is compressed flatly due to the thin shape, the bundled striated body moves along with the compression inside the container. There was a risk of doing so. Further, since the filaments move randomly, there is a risk that the steam passages are biased. As a result, a sufficient amount of the liquid-phase working fluid is not supplied to the evaporation part of the heat pipe, and there is a possibility that the heat transfer characteristics are impaired and the heat transport capability is hindered.

  In addition, a bundled linear body capable of efficiently refluxing the liquid-phase working fluid by generating capillary pressure in the gap formed between the linear bodies as described above is not a flat type, a circular cross section, etc. When inserted into a heat pipe container and used, when the wick gripping member is provided, the above-described problems occur. When the wick gripping member is not provided, the bound filaments move randomly, and the above-described flatness is caused. There were the same problems as the heat pipe of the mold.

  Therefore, the present invention aims to solve the above-mentioned problems of the prior art and to improve the heat transport capability of the heat pipe, in particular to improve the heat transport capability of the flat heat pipe.

  The present invention as a means for solving the above-described problem is that the internal space of the intermediate portion formed between the evaporation portion and the condensation portion formed at both ends of the heat pipe container is arranged in the longitudinal direction of the heat pipe container. Further, the heat pipe container is divided into a plurality of hollow portions by a partition wall.

  Further, the internal space of the intermediate part formed between the evaporation part and the condensation part formed at both ends of the heat pipe container is divided into a plurality of hollow parts by partition walls in the longitudinal direction of the heat pipe container, and at least 1 A plurality of filaments are inserted into each of the hollow parts, and a filament is not inserted into at least one of the hollow parts.

  In the heat pipe, the plurality of filaments inserted into the single hollow portion are bundled.

  In the heat pipe, the heat pipe container is a flat shape, and is a heat pipe.

  According to the present invention as described above, when a container having a hollow structure in which the interior is divided into a plurality of spaces is used, and a linear body bundled in one or more of the spaces is inserted, it is crushed flatly It is possible to prevent the filaments from being disconnected or dispersed from each other, and it is possible to maintain a gap formed by the filaments that generate capillary pressure. In addition, even if the filaments are not bound, by filling the hollow portions so as to fill the hollow portions, it is possible to prevent the plurality of filaments from being dispersed and to form gaps between the filaments that generate capillary pressure. It became possible to maintain.

  Also, since nothing is inserted into at least one space, the space is secured, so the steam passage inside the container is secured, and the partition functions as a heat conduction source, so The heat resistance of the heat pipe can be reduced. As a result, the heat transport efficiency of the heat pipe is not lowered, and the heat transport efficiency is not lowered even by flat processing, and the heat transport capacity is improved, and the heat pipe is stable. Was able to work.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 are views showing a first embodiment of the heat pipe of the present invention. The heat pipe 1 includes a heat pipe container 2 having a circular cross section, a plurality of filaments 5, a working fluid (not shown), It is configured with.

  The heat pipe container 2 has a hollow cylindrical shape having an internal space 25, and an evaporation portion 21 that evaporates the working fluid by heat input from the outside and the evaporated working fluid radiate heat at both ends of the heat pipe container 2. Thus, a condensing part 23 that condenses is formed, and an intermediate part 22 is formed between the evaporating part 21 and the condensing part 23. The heat pipe container 2 is not limited to a cylindrical shape as long as it has a hollow structure having an internal space 25, and may have a polygonal shape in a vertical cross section. The evaporating unit 21 is in contact with a heating element (not shown).

  The internal space 25 of the evaporating unit 21 and the condensing unit 23 is not divided and is constituted by one space. The internal space 25 of the intermediate portion 22 is divided into a plurality of hollow portions 4 by the partition walls 3 in the longitudinal direction of the heat pipe container 2, and each hollow portion 4 has internal spaces of the evaporation portion 21 and the condensation portion 23 at both ends thereof. 25 is connected. It is preferable that the vertical cross-sectional shape of the intermediate portion 22 is the same at any location, that is, the vertical cross-sectional shape of each hollow portion 4 is the same at any location. By setting it as such a shape, the clearance gap between the linear bodies 5 inserted or filled can be maintained reliably.

  The number of hollow portions 4 formed, the longitudinal cross-sectional shape, i.e., the cross-sectional shape of the partition wall 3 is not particularly limited, as long as two or more hollow portions 4 may be formed, but when the heat pipe container 2 is crushed and deformed, In particular, when deformed into a flat shape, it is preferable to form the partition wall 3 so as to be able to cope with such deformation and to maintain the state in which the hollow portion 4 is isolated from the other hollow portions 4 without being damaged. .

  For this reason, the partition 3 is provided in the center of the internal space 25 so as to form the hollow portion 4 having a polygonal cross section, and the partition 3 is in contact with the inner wall surface 20 of the heat pipe container 2 from the apex or side of the polygon. It is preferable to form a plurality of hollow portions 4 by extending. Specifically, as shown in FIG. 2 (b), one hollow portion 4 having a hexagonal cross section is formed at the center of the internal space 25, and the heat pipe container 2 is formed from the apex of the hexagon. A shape in which the partition wall 3 in contact with the inner wall surface 20 is extended to form seven hollow portions 4 can be employed.

  The hollow portion 4 provided at the center of the internal space 25, that is, the hollow portion 4 formed by the partition wall 3 that does not directly contact the inner wall surface 20 of the heat pipe container 2, is not limited to a polygonal shape in the longitudinal section, A circular shape including a deformed circular shape, a semicircular shape, or other shapes may be used. Instead of providing one hollow portion 4 at the center of the internal space 25, a plurality of hollow portions 4 may be provided.

  The material of the heat pipe container 2 is not particularly limited, but it is desirable to use copper in terms of heat conduction performance. The inner diameter of the heat pipe container 2 is not particularly limited, but is usually about several mm for cooling an electronic component attached to the electronic device. Further, the inner wall including the partition wall 3 and the inner wall surface 20 of the heat pipe container 2 may be subjected to a surface roughening treatment such as an oxide film treatment, sand blasting or etching in order to improve wettability. Also, the manufacturing method of such a hollow shape is not particularly limited.

  A plurality of linear bodies 5 are inserted into at least one of the hollow portions 4 provided. The gaps between the plurality of filaments 5 constitute a wick of the heat pipe 1. Further, the filament 5 is not inserted into at least one of the hollow portions 4. The hollow portion 4 in which the linear body 5 is not inserted mainly serves as a steam flow path. Although the wire body 5 is not specifically limited, For example, it can be comprised by the cross-sectional circle-shaped extra fine wire of copper. The diameter is not particularly limited, but a diameter of about 50 to 100 μm can be used. In addition, the filament 5 may be subjected to an oxide film treatment or a roughening treatment in order to improve wettability.

  The linear body 5 is disposed along the longitudinal direction of the heat pipe container 2, penetrates the hollow portion 4, and both end portions protrude into the internal space 25 of the evaporation unit 21 and the condensation unit 23, or enter the internal space 25. Has reached. The plurality of linear bodies 5 inserted into one hollow portion 4 may or may not be bound as long as a fine gap formed by the linear bodies 5 is formed. Therefore, when the linear body 5 is filled so as to fill the hollow portion 4, it is not necessary to bind the linear body 5, but in other cases, the linear body 5 is bound and bound between the linear bodies 5. It is necessary to form a fine gap. In the case of binding, in addition to binding a bundle of filaments 5 using other linear members, a plurality of filaments 5 may be twisted and bound.

  In this way, the filaments 5 in the hollow part 4 are filled or bound so as to fill the hollow part. As a result, a fine gap is formed and secured. In particular, even when the heat pipe container 2 is deformed, a fine gap is always formed and secured by the filaments 5. Therefore, the capillary pressure for the working fluid to recirculate is always maintained. Moreover, the inside of the heat pipe container 2 is not moved randomly. Moreover, since the filament 5 is not inserted in at least one hollow portion 4, a sufficient steam passage can be secured.

  The heat pipe container 2 is filled with a predetermined amount of a condensable fluid such as pure water or alcohol as a working fluid (not shown) in a vacuum deaerated state.

  In the heat pipe 1, heat is transmitted to the evaporation section 21, for example, by a heating element (not shown) coming into contact with the evaporation section 21 at one end of the heat pipe 1. The working fluid enclosed in the heat pipe container 2 is heated and evaporated by the heat transferred to the evaporation unit 21. As a result, the internal pressure of the evaporating unit 21 is increased, whereas in the condensing unit 23 at the other end, the temperature is decreased by heat dissipation, and thus the internal pressure is decreased. Therefore, the vapor of the working fluid flows toward the condensing part 23 due to the pressure difference, and mainly flows through the hollow part 4 in which the filament 5 is not inserted. And the vapor | steam of a working fluid loses heat in the condensation part 23, dissipates heat, and condenses.

  In this way, the working fluid is liquefied in the condensing part 23, and refluxed toward the evaporation part 21 through the fine gap formed by the linear bodies 5 of the hollow part 4. That is, when the working fluid evaporates in the evaporating unit 21, a capillary pressure is generated, and the liquid phase working fluid is caused to flow toward the evaporating unit 21 by the capillary pressure. In this way, the fine gap formed between the filaments 5 functions as a wick, the working fluid is repeatedly evaporated, condensed, and refluxed, heat is transported, and the heating element is cooled.

  Since it is such a structure, the capillary pressure for a liquid phase working fluid to recirculate | circulate can be maintained, and the fine clearance gap formed by the filaments 5 functions as a wick, and a liquid phase is formed with the capillary pressure. The working fluid can be recirculated from the condenser 23 to the evaporator 21. Moreover, the clearance gap formed by the linear bodies 5 becomes a reflux path of a liquid phase working fluid.

  Therefore, the recirculation of the liquid-phase working fluid is performed mainly in the hollow portion 4 in which the filament 5 is inserted, while the gas-phase working fluid is mainly in the hollow portion 4 in which the filament 5 is not inserted. Therefore, most of the reflux path of the liquid phase working fluid is cut off from the flow path of the gas phase working fluid.

  For this reason, the ratio of the liquid phase working fluid in the middle of refluxing being directly exposed to the gas phase working fluid flowing at high speed becomes low. As a result, the reflux performance of the liquid phase working fluid is improved. Therefore, a large amount of heat can be transported without causing dryout in the evaporation section 21, and furthermore, since the partition 3 functions as a heat conduction source, the thermal resistance as a heat pipe can be reduced. As a result, the heat transport capability of the heat pipe 1 can be improved.

  FIG. 3 is a view showing a second embodiment of the heat pipe of the present invention. The heat pipe 6 is a flat, rectangular shape by crushing the circular heat pipe container 2 shown in FIG. The heat pipe container 7 is formed in a shape in which both side surfaces are arcuate. In addition, the same code | symbol is attached | subjected to the same part as 1st embodiment shown in FIG.1 and 2, and the description is abbreviate | omitted.

  The flat shape of the heat pipe 6 is not limited to a shape in which both longitudinal sides of the longitudinal section are rectangular, and the longitudinal section may be thin such as an elliptical shape or a rectangular shape.

  As shown in FIG. 4 (b), the linear body 5 is inserted into a certain space in the heat pipe container 7, the hollow part 4, so that the linear body 5 is crushed for flattening. Is prevented from being disconnected or dispersed, and a fine space between the filaments 5 is secured. Moreover, the filament 5 does not move at random, and the steam passage is not biased. In addition, since it is divided into a plurality of hollow portions 4 in this way, even when flattened, the partition walls 3, in particular, the bent portions of the partition walls 3 are bent, and each hollow portion 4 changes its shape, but other hollow portions 4 Since the state isolated from the part 4 is maintained, a steam path is secured. Furthermore, since the partition 3 functions as a heat conduction source, the thermal resistance as a heat pipe can be reduced. As a result, the heat transport capability of the heat pipe 6 can be improved. Furthermore, since the heat pipe 6 is a flat type, it can be installed in an electronic device such as a personal computer which is thin and difficult to provide a space in the height direction inside the housing, and efficiently cools or dissipates heat of electronic components. I can do it.

  The heat pipes 1 and 6 as described above are suitably used for cooling an electronic component attached to an electronic device, but are not limited to this application and can be widely used as a heat pipe.

Heat pipe first embodiment perspective view of the present invention It is sectional drawing of FIG. 1, (a) is an AA cross section, (b) is a BB cross section, (c) is a CC cross section. The heat pipe second embodiment perspective view of the present invention FIG. 4 is a cross-sectional view of FIG. 3, where (a) is a DD cross section, (b) is an EE cross section, and (c) is an FF cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pipe 2 Heat pipe container 20 Inner wall surface 21 Evaporating part 22 Intermediate part 23 Condensing part 25 Internal space 3 Partition 4 Hollow part 5 Striated body 6 Heat pipe 7 Heat pipe container

Claims (4)

  A heat characterized by dividing the internal space of the intermediate part formed between the evaporation part and the condensation part formed at both ends of the heat pipe container into a plurality of hollow parts by partition walls in the longitudinal direction of the heat pipe container. Pipe container.   An internal space of an intermediate portion formed between the evaporation portion and the condensation portion formed at both ends of the heat pipe container is divided into a plurality of hollow portions by partition walls in the longitudinal direction of the heat pipe container, and at least one A heat pipe, wherein a plurality of filaments are inserted into the hollow part, and no filaments are inserted into at least one of the hollow parts.   The heat pipe according to claim 2, wherein the plurality of filaments inserted into the single hollow portion are bundled.   The heat pipe according to claim 2 or 3, wherein the heat pipe container is a flat type.

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