JP2006125683A - Heat transporting device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat transporting device and electronic equipment loading the same, capable of surely preventing drying-out, and realizing high heat transporting performance. <P>SOLUTION: In this invention, channel resistance of a channel of a liquid-phase pipe 4 is determined to be larger than that of a liquid-phase channel 8 of an evaporator 1. That is, capillary force of the channel of the liquid-phase pipe 4 is determined to be larger than that of the liquid-phase channel 8 of the evaporator 1. The working fluid of liquid phase can be strongly sucked from a condenser 2 by the comparatively strong channel resistance of the liquid-phase pipe 4, even when bubbles or the like are generated in the liquid-phase channel 8 of the evaporator caused by excessive heat of a heating element. Thus the drying-out can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat transport device that absorbs heat of a heating element and transports heat by circulating a working fluid using a capillary force as a driving force, and an electronic device equipped with the heat transport device.

  In order to cool an electronic device such as a PC (Personal Computer), a heat pipe, a CPL (Capillary Pumped Loop) or the like has been conventionally used as a device for transporting heat generated from a heat generating portion of the electronic device to a heat radiating portion. Yes. In these heat transport devices, the vapor phase working fluid evaporated by the heat generated in the high-temperature heat generating part of the electronic equipment moves to the low-temperature heat-dissipating part, condenses in the heat-dissipating part, becomes liquid, and releases heat. As a result, the heating element is cooled.

  The heat pipe contains a working fluid serving as a refrigerant in a pipe-shaped container made of a metal such as copper, and generates a pumping force in the working fluid by a wick that generates a capillary force provided inside the pipe (for example, (See Patent Document 1).

CPL is a heat transport device using the principle of a heat pipe, and its shape is not limited to a pipe shape. For example, in CPL, an evaporator and a condenser are physically separated, and an evaporator and a condenser are a gas phase tube through which a gas phase working fluid flows and a liquid phase tube through which a liquid phase working fluid flows. There is a device connected to each other (see, for example, Patent Document 2).
JP 2001-251080 (paragraph [0031], FIG. 8) JP 2004-85186 A (paragraph [0025], FIG. 1)

  However, for example, when the heating element is an IC chip, the degree of integration of the IC chip has been improved year by year, and the clock speed has been increased. The amount of heat generation accompanying this increase is steadily increasing. Therefore, it is becoming a situation where dryout is likely to occur due to such excessive heat generation. Further, in order to cope with the problem of an increase in the amount of heat generation, a heat transport device having higher heat transport efficiency will be required in the future.

  In view of the circumstances as described above, an object of the present invention is to provide a heat transport device that can reliably prevent dry-out and realize a high heat transport capability, and an electronic device equipped with the heat transport device. is there.

  In order to achieve the above object, a heat transport device according to the present invention has a first flow path having a first flow path resistance for circulating a liquid-phase working fluid, and a heating element by an evaporation effect of the working fluid. An evaporator that absorbs heat from the condenser, a condenser that releases heat by a condensing action of the working fluid, a first pipe that circulates the working fluid evaporated in the evaporator to the condenser, and the first A second pipe having a second flow path having a second flow path resistance different from the flow path resistance and capable of flowing the working fluid condensed by the condenser to the first flow path. It comprises.

  In the present invention, it is assumed that the smaller the contact area per unit stroke length at which the working fluid contacts each flow path (the area where the working fluid contacts the wall constituting the flow path), the smaller the flow path resistance. On the other hand, the capillary force (or surface tension) decreases as the contact area decreases, but the flow path resistance referred to in the present invention is independent of the capillary force when the working fluid flows by the capillary force. The same applies hereinafter.

  In the present invention, the first flow path resistance of the first flow path of the evaporator and the second flow path resistance of the second flow path of the second pipe are set to optimum values, respectively. By being set, an optimum capillary force acts on the liquid-phase working fluid. Thereby, a working fluid can be distribute | circulated stably and a high heat transport capability can be implement | achieved.

  The second tube may be configured such that part or all of the inside through which the working fluid flows is configured by the second flow path. Examples of the heating element include an electronic component such as an IC chip and a resistor, a heat radiating fin, and the like. The same applies hereinafter.

  According to one aspect of the present invention, the second flow path resistance is greater than the first flow path resistance. Thereby, the capillary force of the second channel can be made larger than the capillary force of the first channel. Therefore, even when bubbles or the like are generated in the first flow path of the evaporator due to excessive heat of the heating element, the liquid phase working fluid can be strongly drawn by the relatively large second flow path resistance. And can prevent dry-out.

  According to an aspect of the present invention, the second pipe is provided closer to the condenser than the second flow path, and is a third flow path different from the first and second flow path resistances. A third flow path having resistance is included. By optimizing each channel resistance also in the second pipe, the working fluid can be stably circulated in the second channel, and the heat transport capability can be improved.

  According to one aspect of the present invention, the third flow path resistance is greater than the second flow path resistance. Thereby, the working fluid flowing out from the condenser to the second pipe can be circulated stably to the evaporator, and the heat transport capability can be improved.

  According to an aspect of the present invention, the first flow path includes a first end portion on the downstream side of the working fluid and a second end portion on the upstream side of the working fluid, The second channel includes a third end connected to the second end so that the second channel communicates with the first channel, and a second end upstream of the working fluid. The first flow path and the second flow path are linear from the fourth end to the first end, and the flow path resistance gradually decreases. It is provided to become. Thereby, the liquid working fluid can be circulated more stably. For example, even when bubbles are generated in the first flow path, the bubbles can be prevented from flowing into the second tube from the evaporator. The gradually decreasing channel resistance means that the channel resistance decreases continuously, stepwise, or in a mixed state.

  For example, the evaporator has a first particle having a first size for constituting the first flow path, and the second tube constitutes the second flow path. Therefore, it is only necessary to have a second particle having a second size smaller than the first size. A grain is a sphere, ellipsoid, cuboid, cube, or a combination of at least two of these. The size is the size of the largest portion of one grain.

  Not only the particles but also a plurality of rod-like members along the flow direction of the working fluid may be collected, and each flow path may be configured. In this case, the rod-shaped member may be a hollow pipe or a non-hollow rod-shaped member. Alternatively, it may be a porous member (a sponge-like member in which a plurality of voids are formed). In the case of a hollow pipe, the hollow diameter (diameter in a direction orthogonal to the flow direction) may be different in the flow direction. Similarly, in the case of a non-hollow rod-like member, it is only necessary that the diameter is different in the flow direction.

  Alternatively, the evaporator has a first groove having a first width for configuring the first flow path, and the second tube is configured for configuring the second flow path. It is only necessary to have a second groove having a second width narrower than the first width. The width in this case is a width in a direction perpendicular to the direction in which the working fluid flows.

  According to an aspect of the present invention, the first tube has a hydrophobic third flow path for the working fluid. The molecules of the working fluid in the gas phase progress while repeating collisions in the first tube. When the thermal diffusion is large in the third flow path, the vapor phase working fluid is condensed due to the thermal diffusion, and heat cannot be efficiently transported to the condenser. In the present invention, thermal diffusion in the third flow path is suppressed, and the heat transport capability can be improved. Further, in order to realize hydrophobicity, for example, if a resin tube is used as the first tube, the thermal conductivity becomes lower than that of metal, so that thermal diffusion can be suppressed. In this case, the outside of the tube can be made of metal and the inside of the tube in contact with the working fluid can be made of plastic.

  A heat transport device according to another aspect of the present invention includes an evaporator that absorbs heat from a heating element by an evaporation action of a working fluid, a condenser that releases heat by a condensation action of the working fluid, and an evaporation by the evaporator The working fluid condensed by the condenser has a first pipe that causes the working fluid to flow to the condenser, and a flow path that gradually reduces the flow resistance along the direction in which the working fluid flows. And a second pipe capable of circulating the gas to the evaporator.

  In the present invention, the flow path resistance of the second flow path through which the condensed liquid phase working fluid flows gradually decreases along the flow direction of the working fluid, so even when bubbles or the like are generated in the evaporator, The liquid phase working fluid can be strongly drawn in the flow path in the second pipe, and dry-out can be prevented.

  An electronic apparatus according to the present invention includes a heating element, an evaporator that absorbs heat from the heating element by an evaporation action of the working fluid, a condenser that releases heat by the condensation action of the working fluid, and an evaporation by the evaporator The working fluid condensed by the condenser has a first pipe that causes the working fluid to flow to the condenser, and a flow path that gradually reduces the flow resistance along the direction in which the working fluid flows. And a second pipe capable of circulating the gas to the evaporator.

  An electronic apparatus according to another aspect of the present invention includes a heating element, an evaporator that absorbs heat from the heating element by an evaporation action of the working fluid, a condenser that releases heat by the condensation action of the working fluid, A first pipe that circulates the working fluid evaporated in an evaporator to the condenser; and a first passage that gradually reduces the passage resistance along a direction in which the working fluid circulates. A second pipe capable of circulating the working fluid condensed in the vessel to the evaporator.

  Examples of each electronic device include a computer, a PDA (Personal Digital Assistance), an electronic dictionary, a camera, a display device, an audio device, a mobile phone, and other electrical appliances. The same applies hereinafter.

  As described above, according to the present invention, dry-out can be reliably prevented and high heat transport capability can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a heat transport device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the heat transport device 10 shown in FIG.

  The heat transport device 10 includes an evaporator 1 that evaporates the working fluid accommodated therein and absorbs heat of a heating element (not shown), and a condenser 2 that condenses the evaporated working fluid and releases heat. ing. Between the evaporator 1 and the condenser 2, a gas phase pipe 3 for circulating the working fluid evaporated in the evaporator 1 to the condenser 2 and a liquid for circulating the working fluid condensed in the condenser 2 to the evaporator 1. The phase tube 4 is connected. A plurality of, for example, two gas phase tubes 3 and two liquid phase tubes 4 are provided. By providing each of the tubes 3 and 4 in this way, for example, even if bubbles occur in one of the liquid phase tubes 4, operation is performed using the other liquid phase tubes 4. Fluid can be circulated.

  As the working fluid, for example, pure water, ethanol, methanol, acetone, isopropyl alcohol, alternative chlorofluorocarbon, ammonia or the like is used. In addition, it is desirable that a surfactant be added to the working fluid. The working fluid to which the surface active agent is added becomes hydrophilic, and the wettability with respect to each flow path in the heat transport device 10 is enhanced as will be described later, so that the efficiency of heat transport can be enhanced. Examples of the surface active agent include general soaps to polyethylene glycol, ionic, nonionic, amphoteric (active agents having two properties of ionic and nonionic).

  When the electronic device on which the heat transport device 10 is mounted is a camera, a PDA, or the like, and the usage environment temperature range is −25 ° C. to 40 ° C., pure water cannot be used as the working fluid. In general, ethanol is used as a refrigerant when the above-mentioned use environment temperature is included. However, the latent heat of vaporization is about 1 / 2.5 compared to water (854 kJ / kg versus 2257 kJ / kg), which is disadvantageous in terms of the maximum heat transport amount.

  The effect is great if an additive that increases the operating temperature of the working fluid due to the action of lowering the freezing point is selected while using the additive that increases the hydrophilicity. For example, diethylene glycol mono-n-butyl ether has a melting point of −60 ° C. and is very effective as a working fluid.

  As will be described later, when the evaporator 1 or the like is composed of silicon and Pyrex (registered trademark) glass, when water is used as the working fluid, the silicon and Na in the glass react with water, for example, non-condensable Gas hydrogen may be generated, which may affect the life and performance of the heat transport device. Therefore, for example, as a substance to be added to the working fluid, for example, an antioxidant or the like having an action of expanding the use range of the refrigerant while suppressing the reaction between water and the base material (the base material constituting the evaporator 1) is selected. If it is, the effect is great.

  As shown in FIG. 2, the evaporator 1 includes a rectangular upper substrate 11 and a lower substrate 12. The upper substrate 11 is made of glass as described above, and for example, Pyrex (registered trademark) glass is used. On the other hand, the lower substrate 12 is made of silicon. Both substrates 11 and 12 are joined by, for example, anodic bonding. In the upper substrate 11 or the lower substrate 12, a liquid phase channel 8 through which a liquid phase working fluid returning from the liquid phase tube 4 flows is formed in a groove shape, for example. These liquid phase flow paths 8 are provided linearly along the longitudinal direction (X direction) of the liquid phase tube 4 at both ends in the width direction (Y direction) of the evaporator 1. The lower substrate 12 is formed with a plurality of grooves 12a through which the working fluid flows in the Y direction. While the working fluid flows through these grooves 12a, the heat is absorbed by evaporating by heat from the heating element 15 that is in thermal contact with the lower surface side of the evaporator 1. These liquid phase flow path 8, groove 12a, and the like are produced by, for example, a photolithography technique in semiconductor manufacturing, cutting, or the like.

  Like the evaporator 1, the condenser 2 includes a rectangular upper substrate 13 and a lower substrate 14. The upper substrate 13 is made of glass, for example, Pyrex (registered trademark) glass is used. On the other hand, the lower substrate 14 is made of silicon. Both substrates 13 and 14 are joined by, for example, anodic bonding. The upper substrate 13 and the lower substrate 14 are provided with grooves 13a (see FIG. 1) and 14a that serve as a flow path for the working fluid. These grooves 13a and 14a are formed by, for example, photolithography or cutting. Produced. Further, as shown in FIG. 1, the upper substrate 13 of the condenser 2 is formed with an injection hole 13b for the working fluid. The injection hole 13b is sealed by a lid 5 made of a metal such as copper or aluminum, so that the inside of the condenser 2 is airtight. Further, the upper substrate 13 is provided with a connection hole 13c for connecting the gas phase tube 3 and the liquid phase tube 4 and these communicate with the grooves 13a and 14a.

  In the evaporator 1, the upper substrate 11 is provided with a connection hole 11 b for connecting the gas phase tube 3 and the liquid phase tube 4, and the connection hole 11 b communicates with the liquid phase channel 8. Similarly, the condenser 2 is provided with a connection hole 13c for connecting the gas phase tube 3 and the liquid phase tube 4 and communicates with the grooves 13a and 14a. The gas phase tube 3 and the liquid phase tube 4 are made of a metal such as aluminum, copper, or stainless steel, for example. The gas phase tube 3 and the like and the connection holes 11b and 13c are joined by, for example, anodic bonding or solder bonding.

  The gas phase tube 3 is preferably made of a hydrophobic material. This is because if the thermal diffusion in the gas phase tube 3 is large, the vapor phase working fluid is condensed due to the thermal diffusion, and heat cannot be efficiently transported to the condenser 2. By making it hydrophobic, thermal diffusion inside the gas phase tube 3 can be suppressed, and the heat transport capability can be improved. Even when an additive such as a surfactant for enhancing hydrophilicity is added to the working fluid as described above, the working fluid contributes to such hydrophilicity when the working fluid is in a gas phase state. No, that is not a problem. Therefore, even if the working fluid to which the additive has been added flows through the gas phase tube 3 in a gas phase state, thermal diffusion can be suppressed. Further, if the gas phase tube 3 is hydrophobic, thermal diffusion can be further suppressed. .

  In order to realize the hydrophobicity, for example, an organic tube such as Teflon (registered trademark), polyimide, or polyimide may be provided on a wall constituting the flow path of the gas phase tube 3. In this case, the outer side of the liquid phase tube 4 is made of, for example, a metal such as stainless steel, copper, aluminum, titanium, nickel, iron, cobalt, etc., and the Teflon (registered trademark) processing is performed inside the metal tube. Processing can be performed. The outer side is made of metal, and each flow path of the heat transport device 10 is generally in a reduced pressure state according to the operating temperature of the working fluid, and the rigidity of the tube is set high so as to maintain the reduced pressure state. Because you have to do it.

  FIG. 3 is a view for explaining the internal structure of the liquid phase flow path 8 and the liquid phase pipe 4 of the evaporator 1. In FIG. 3, cross sections of the liquid phase flow path 8 and the liquid phase pipe 4 are shown on the right.

  As described above, the liquid phase flow path 8 of the evaporator 1 is configured such that the grooves formed in the upper substrate 11 or the lower substrate 12 are filled with the granules 9a having the first diameter. The liquid phase tube 4 includes, for example, a portion 4a on the side close to the evaporator 1 (downstream of the working fluid in the liquid phase tube 4) and a portion 4b on the side close to the condenser 2 (upstream of the working fluid in the liquid phase tube 4). It becomes. The flow path in the part 4a is configured by being filled with granules 9b having a second diameter smaller than the first diameter of the granules 9a. Furthermore, the flow path in the part 4b is configured by being filled with particles 9c having a third diameter smaller than the second diameter. These granules 9a to 9c are spherical, for example, but are not limited thereto. The particles 9a are bonded so as to come into contact with each other with a three-dimensional extent so as not to flow with the working fluid. The same applies to the grains 9b and 9c.

  The smaller the diameter of the granule, the larger the area where the working fluid contacts the surface of the granule, and the smaller the volume of the space constituting the flow path (the smaller the porosity). As the volume of the space constituting the flow path decreases, the flow path resistance increases and the capillary force also increases. In this way, the diameters of the granules 9a to 9c are set so that the flow path resistance with respect to the working fluid gradually decreases from the upstream portion 4b of the liquid phase pipe 4 to the liquid phase flow path 8 of the evaporator 1. Has been. In this case, it is preferable to make the flow resistance of the flow path constituted by the groove 12a of the evaporator 1 or the capillary force smaller than the flow resistance of the liquid phase flow path 8. This is the same as widening the space in which the working fluid can flow from the liquid phase flow path 8 to the groove 12a, whereby the working fluid easily changes from the liquid phase to the gas phase due to the heat of the heating element 15. Thus, the heat transport efficiency is increased.

  Operation | movement of the heat transport apparatus 10 comprised as mentioned above is demonstrated.

  The heat generated by the heating element 15 is transmitted to the lower substrate 12, and a part of the working fluid in the evaporator 1 is evaporated by this heat. The evaporated working fluid flows through the two gas phase pipes 3 and flows into the flow path in the condenser 2. The working fluid that has flowed into the condenser 2 flows through the grooves 14a and the like, thereby transferring heat to the upper substrate 13 and the lower substrate 14 to condense. The heat transmitted to the upper substrate 13 and the lower substrate 14 is released to the outside of the condenser 2.

  The condensed working fluid flows through the two liquid phase tubes 4 and flows into the liquid phase flow path 8 in the evaporator 1, and the working fluid flows through the liquid phase flow path 8. In this case, the working fluid is circulated by the capillary force through the flow paths having different capillary forces configured by the granules 9c, 9b, and 9a. The working fluid flowing through the liquid phase flow path 8 in the evaporator 1 flows through the groove 12a while changing phase from the liquid phase to the gas phase.

  By repeating the operation as described above, the heat of the heating element 15 can be transported to the condenser 2 side, and the heat generated by the heating element 15 can be released to the outside of the condenser 2 to cool the heating element.

  In the present embodiment, the flow path resistance of the liquid phase tube 4 is set to be larger than the flow path resistance of the liquid phase flow path 8 of the evaporator 1. That is, the capillary force of the flow path of the liquid phase tube 4 is set to be larger than the capillary force of the liquid phase flow path 8 of the evaporator 1. Thereby, even when bubbles or the like are generated in the liquid phase flow path 8 of the evaporator due to excessive heat of the heating element 15, the liquid phase working fluid is condensed by the flow resistance of the relatively large liquid phase pipe 4. It can be pulled in strongly from the vessel 2. Therefore, dryout can be prevented.

  Also in the flow path in the liquid phase tube 4, since the capillary force on the upstream side 4 b is set higher than the capillary force on the downstream side 4 a, the working fluid flowing out from the condenser 2 to the liquid phase tube 4 is removed from the evaporator. 1 can be circulated stably, and the heat transport capability can be improved. In addition, since the liquid phase flow path 8 of the evaporator 1 is provided in a straight line along the straight liquid phase pipe 4, the liquid working fluid can be circulated more stably. Can be reliably prevented.

  FIG. 4 is a diagram illustrating a liquid phase channel and a liquid phase tube according to another embodiment. The liquid phase flow path 18 is constituted by an internal member 25 in which a groove 19a is extended along the flow direction of the working fluid (in FIG. 4, a direction perpendicular to the paper surface). The flow path in the downstream portion 24a of the liquid phase tube 24 is constituted by an internal member 26 in which a groove 19b having a width narrower than the width of the groove 19a is extended. The flow path in the upstream portion 24b of the liquid phase tube 24 is constituted by an internal member 27 in which a groove 19c having a width narrower than the width of the groove 19b is extended. That is, the width of the groove is gradually narrowed from the upstream side of the liquid phase pipe 24 to the liquid phase flow path 8 along the flow direction of the working fluid. As a result, the flow path resistance or capillary force gradually decreases along the flow direction of the working fluid, and the same effects as those in the liquid phase flow path 8 and the liquid phase pipe 4 according to the above embodiment can be obtained. it can. For the internal members 25, 26, and 27, for example, metal, resin, or the like can be used.

  5 and 6 are cross-sectional views showing a liquid phase flow path or a liquid phase pipe according to still another embodiment. The flow path shown in FIG. 5 is configured by, for example, a plurality of inner pipes 31 in which the inner diameter a gradually increases along the arrow A, which is the flow direction of the working fluid, in the liquid phase pipe 4. The flow path shown in FIG. 6 is configured, for example, by providing a plurality of rod-shaped members 32 whose diameter b gradually decreases along the arrow A, which is the flow direction of the working fluid, in the liquid phase tube 4. . Even with such a configuration, the same effects as those of the liquid phase flow path 8 and the liquid phase pipe 4 according to the above embodiment can be obtained.

  The present invention is not limited to the embodiment described above, and various modifications are possible.

  For example, the form of the evaporator 1 or the condenser 2 is not limited to the form described above. For example, the shape of the evaporator 1 and the like is a rectangular plate, but it may be a pentagon or more polygonal or circular plate. Further, when the heat transport device is mounted on an electronic device, various arrangements, shapes, and the like of the evaporator 1 and the condenser 2 can be considered in accordance with the arrangement, shape, and the like of the heating element in the electronic device. The same applies to the shape of the gas phase tube and the liquid phase tube. For example, the cross section is not limited to a circle, and a flat type is also conceivable.

  Further, as forms constituting the liquid phase flow path 8 and the flow path inside the liquid phase pipe 4, the granules 9a to 9c shown in FIG. 3, the grooves 19a to 19c shown in FIG. 4, and the pipe shown in FIG. 31 or a combination of at least two of the rod-like members 32 shown in FIG.

It is a perspective view which shows the heat transport apparatus which concerns on one embodiment of this invention. It is sectional drawing of the heat transport apparatus shown in FIG. It is a figure for demonstrating the internal structure of the liquid phase flow path and liquid phase pipe | tube of an evaporator. It is a figure which shows the liquid phase flow path and liquid phase pipe | tube which concern on other embodiment. It is sectional drawing which shows the liquid phase flow path or liquid phase pipe | tube which concerns on another embodiment. It is sectional drawing which shows the liquid phase flow path or liquid phase pipe | tube which concerns on another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Evaporator 2 ... Condenser 3 ... Gas phase tube 4, 24 ... Liquid phase tube 8, 18 ... Liquid phase flow path 9a-9c ... Granule 10 ... Heat transport apparatus 12a, 13a, 14a, 19a-19c ... Groove 15 ... heating element

Claims (11)

An evaporator that has a first flow path having a first flow path resistance for circulating a liquid-phase working fluid, and that absorbs heat from the heating element by the evaporating action of the working fluid;
A condenser that releases heat by the condensing action of the working fluid;
A first pipe for circulating the working fluid evaporated in the evaporator to the condenser;
A second flow path having a second flow path resistance different from the first flow path resistance is provided, and the working fluid condensed by the condenser can be circulated to the first flow path. A heat transport device comprising: a second pipe. The heat transport device according to claim 1,
The heat transport device according to claim 2, wherein the second flow path resistance is larger than the first flow path resistance. The heat transport device according to claim 1,
The second tube is
Heat transport characterized by having a third flow path provided on the condenser side of the second flow path and having a third flow path resistance different from the first and second flow path resistances apparatus. The heat transport device according to claim 3,
The heat transport device according to claim 3, wherein the third flow path resistance is larger than the second flow path resistance. The heat transport device according to claim 1,
The first flow path is
A first end downstream of the working fluid;
A second end upstream of the working fluid;
The second flow path is
A third end connected to the second end so that the second flow path communicates with the first flow path;
A fourth end upstream of the working fluid;
The first flow path and the second flow path are linearly provided from the fourth end portion to the first end portion, and are provided so that the flow path resistance gradually decreases. Features heat transport device. The heat transport device according to claim 2,
The evaporator has a first particle body having a first size for constituting the first flow path,
The second pipe has a second granular body having a second size smaller than the first size for constituting the second flow path. The heat transport device according to claim 2,
The evaporator has a first groove having a first width for constituting the first flow path,
The second pipe has a second groove having a second width narrower than the first width for constituting the second flow path. The heat transport device according to claim 1,
The heat transport device according to claim 1, wherein the first pipe has a hydrophobic third flow path of the working fluid. An evaporator that absorbs heat from the heating element by the evaporation of the working fluid;
A condenser that releases heat by the condensing action of the working fluid;
A first pipe for circulating the working fluid evaporated in the evaporator to the condenser;
A second pipe having a flow path whose flow resistance gradually decreases along a direction in which the working fluid flows, and capable of flowing the working fluid condensed by the condenser to the evaporator; A heat transport device comprising: A heating element;
An evaporator that has a first flow path having a first flow path resistance for flowing a liquid-phase working fluid, and that absorbs heat from the heating element by an evaporation action of the working fluid;
A condenser that releases heat by the condensing action of the working fluid;
A first pipe for circulating the working fluid evaporated in the evaporator to the condenser;
A second flow path having a second flow path resistance different from the first flow path resistance is provided, and the working fluid condensed by the condenser can be circulated to the first flow path. An electronic device comprising: a second tube. A heating element;
An evaporator that absorbs heat from the heating element by the evaporation of the working fluid;
A condenser that releases heat by the condensing action of the working fluid;
A first pipe for circulating the working fluid evaporated in the evaporator to the condenser;
A second pipe having a flow path whose flow resistance gradually decreases along a direction in which the working fluid flows, and capable of flowing the working fluid condensed by the condenser to the evaporator; An electronic device comprising the electronic device.

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