JP2017227383A - Wick - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that can inhibit a segment from being damaged.SOLUTION: A wick 2 for a heat pipe 1 includes: a plurality of porous segments 22; and a joint layer 5 for jointing the segment 22 with the segment 22. The segments 22 are arranged so as to form a wick cylindrical body 21, where the segment 22 adjacent to the segment 22 are jointed by the joint layer 5.SELECTED DRAWING: Figure 4

Description

  The technology disclosed herein relates to a wick of a heat pipe.

  The heat pipe disclosed in Patent Document 1 includes a wick and a case. The wick and the case are formed in a cylindrical shape. The wick is formed from a porous material, and the case is formed from a dense metal material. A liquid flow path is formed in the internal space of the wick, and a liquid working fluid flows through the liquid flow path. The case covers the outer surface of the wick. A gas flow path is formed in the space between the case and the wick, and a gas working fluid flows through this gas flow path. Further, the case is heated by the heat transfer block, and heat is transferred from the case heated by the heat transfer block to the wick.

  In the heat pipe of Patent Document 1, when a liquid working fluid flows through the liquid flow path, the working fluid penetrates into the porous wick by capillary action. The liquid working fluid that has permeated the wick receives the heat transferred from the case to the wick, evaporates, and changes its state to a gaseous working fluid. The evaporated working fluid flows into the gas channel from the wick and flows through the gas channel.

JP 2011-190996 A

  In the technique of Patent Document 1, the evaporation rate when the liquid working fluid evaporates may vary depending on the location in the wick. For example, when the liquid working fluid flows through the liquid flow path, the pressure of the liquid working fluid relative to the wick is relatively high in the vertical lower part of the wick, and the pressure of the liquid working fluid relative to the wick is high in the vertical upper part of the wick. The pressure of the liquid working fluid is relatively low. Due to the difference in pressure of the liquid working fluid, the liquid working fluid evaporates relatively quickly in the lower part of the wick and the liquid working fluid evaporates relatively slowly in the upper part of the wick. As a result, the evaporation rate of the liquid working fluid is different.

  As described above, if the evaporation speed of the liquid working fluid varies depending on the location in the wick, it is conceivable to change the characteristics of the wick depending on the location in the wick in order to suppress this. For example, in a porous wick, it is conceivable to change the pore diameter of the wick depending on the location. It is conceivable to increase the pore diameter at the lower part of the wick and reduce the pore diameter at the upper part of the wick. In order to change the characteristics of the wick depending on the location, it is conceivable to divide one wick into a plurality of segments and change the characteristics of each segment. This allows the wick characteristics to vary from place to place.

  When one wick is divided into a plurality of segments, when some force acts on the wick, the force acts on the plurality of segments constituting the wick. For example, thermal stress when the wick is heated acts on a plurality of segments constituting the wick. When a force is applied to a plurality of segments of the wick, the segments may be cracked to damage each segment. Therefore, the present specification provides a technique capable of suppressing damage to the segments even if the wick is divided into a plurality of segments.

  The heat pipe wick disclosed in the present specification includes a plurality of porous segments, and a bonding layer that bonds the segments to each other. A plurality of segments are arranged side by side so as to form a cylindrical body, and adjacent segments and segments are joined by a joining layer.

  According to such a configuration, when a liquid working fluid flows in a cylinder formed by a plurality of segments, the working fluid penetrates into the porous segment by capillary action. The liquid working fluid that has permeated the segment receives heat from the segment, evaporates, and changes its state to a gaseous working fluid.

  In a wick having a plurality of segments, when some force acts on the wick, the force acts on the plurality of segments constituting the wick. For example, thermal stress when the wick is heated acts on a plurality of segments constituting the wick. For example, when a wick is mounted on an automobile, a force due to the acceleration of the automobile may act on a plurality of segments constituting the wick. Further, gravity acts on each of the plurality of segments constituting the wick.

  Thus, various forces act on the plurality of segments constituting the wick. At this time, according to said structure, the joining layer which joins an adjacent segment functions as a buffer material with respect to various force. As a result, even if some force is applied to the plurality of segments, the bonding layer functions as a cushioning material, thereby preventing a large force from acting locally on each segment. Therefore, even if the wick of the heat pipe is composed of a plurality of segments, it is possible to prevent the segments from being damaged.

  Moreover, in said wick, the several segment is arrange | positioned along with the circumferential direction of the cylinder, and the pore diameter and / or porosity of the segment which adjoins the circumferential direction may differ.

  In a configuration in which a plurality of segments are arranged side by side in the circumferential direction of the cylinder, when a liquid working fluid flows in the cylinder, the pressure of the liquid acting on the segment differs depending on the location in the circumferential direction of the cylinder There is. Thereby, the evaporation speed when the liquid working fluid evaporates may be different depending on the location in the circumferential direction of the cylinder. For example, when the wick is arranged so that the axial direction of the cylinder is perpendicular to the vertical direction, the liquid pressure on the segment is relatively high in the segment at the lower part in the circumferential direction of the cylinder due to the influence of the gravity of the liquid. Become. On the other hand, in the segment at the upper part in the circumferential direction of the cylinder, the liquid pressure on the segment is relatively low. Due to such a pressure difference, in the segment at the lower portion in the circumferential direction of the cylinder, the liquid working fluid penetrates into the porous segment relatively quickly, and the working fluid evaporates at a relatively high rate. On the other hand, in the segment at the upper part in the circumferential direction of the cylindrical body, the liquid working fluid penetrates into the porous segment relatively slowly, and the evaporation speed of the working fluid becomes relatively slow. Therefore, the evaporation speed of the liquid working fluid may be uneven in the circumferential direction of the cylinder.

  Therefore, according to the above configuration, the evaporation speed of the liquid working fluid can be leveled in the circumferential direction of the cylinder by changing the pore diameter and / or the porosity of the segments adjacent in the circumferential direction of the cylinder. it can. For example, in the porous segment at the lower portion in the circumferential direction of the cylindrical body, the pore diameter is increased and the porosity is decreased. According to such a configuration, in the segment at the lower portion in the circumferential direction of the cylindrical body, when the liquid working fluid permeates the segment, the contact area between the working fluid and the segment can be reduced. However, it is possible to make it difficult to receive heat from the segment. In addition, the permeation speed when the liquid working fluid permeates the porous segment can be reduced. As a result, the liquid working fluid can hardly be evaporated, and the evaporation speed can be reduced. On the other hand, in the porous segment at the upper part in the circumferential direction of the cylindrical body, the pore diameter is reduced and the porosity is increased. According to such a configuration, in the segment at the upper part in the circumferential direction of the cylindrical body, when the liquid working fluid permeates the segment, the contact area between the working fluid and the segment can be increased. Can easily receive heat from the segment. In addition, the permeation speed when the liquid working fluid permeates the porous segment can be increased. As a result, the liquid working fluid can be easily evaporated, and the evaporation speed can be increased.

  Thus, by changing the pore diameter and / or the porosity of the porous segment in the circumferential direction of the cylindrical body, the evaporation rate of the liquid working fluid can be adjusted in the circumferential direction of the cylindrical body. Therefore, the evaporation rate of the liquid working fluid can be leveled in the circumferential direction of the cylinder.

  Moreover, in said wick, the several segment is arrange | positioned along with the axial direction of a cylinder, and the pore diameter and / or porosity of the segment adjacent to an axial direction may differ.

  In a configuration in which a plurality of segments are arranged side by side in the axial direction of the cylinder, when a liquid working fluid flows in the cylinder, the pressure of the liquid acting on the segment differs depending on the location in the axial direction of the cylinder There is. As a result, the evaporation rate when the liquid working fluid evaporates may vary depending on the axial position of the cylinder. For example, when the wick is mounted on an automobile and the automobile starts, the force due to the acceleration of the automobile acts relatively on the liquid working fluid. The force due to the acceleration of the automobile acts on the side opposite to the traveling direction of the automobile. When the wick is mounted on an automobile and the axial direction of the cylinder is arranged along the traveling direction of the automobile, the force acting on the liquid by the acceleration of the automobile is along the axial direction of the cylinder. Works. At this time, due to the influence of the force due to the acceleration of the automobile, in the segment on the opposite side to the traveling direction of the automobile in the axial direction of the cylinder (the side where the force due to the acceleration acts), the liquid pressure on the segment increases. On the other hand, in the segment on the traveling direction side of the automobile in the axial direction of the cylinder, the liquid pressure on the segment is relatively low. Due to the difference in pressure, in the segment on the side opposite to the direction of travel of the car in the axial direction of the cylinder (the side on which the force due to acceleration acts), the liquid working fluid quickly penetrates into the porous segment and operates. The evaporation rate of the fluid increases. On the other hand, in the segment on the traveling direction side of the automobile in the axial direction of the cylinder, the liquid working fluid penetrates into the porous segment relatively slowly, and the evaporation speed of the working fluid becomes relatively slow.

  Therefore, according to the above configuration, the evaporation speed of the liquid working fluid can be leveled in the circumferential direction of the cylinder by changing the pore diameter and / or the porosity of the adjacent segments in the axial direction of the cylinder. it can. For example, in the segment on the side opposite to the traveling direction of the automobile in the axial direction of the cylinder (the side on which the force due to acceleration acts), the pore diameter is increased and the porosity is decreased. According to such a configuration, in the segment on the side opposite to the traveling direction of the automobile in the axial direction of the cylinder (the side on which the force due to acceleration acts), when the liquid working fluid penetrates the segment, The contact area of the segment can be reduced, and the liquid working fluid can hardly receive heat from the segment. In addition, the permeation speed when the liquid working fluid permeates the porous segment can be reduced. As a result, the liquid working fluid can hardly be evaporated, and the evaporation speed can be reduced. On the other hand, in the segment on the traveling direction side of the automobile in the axial direction of the cylinder, the pore diameter is reduced and the porosity is increased. According to such a configuration, when the liquid working fluid permeates into the segment, the contact area between the working fluid and the segment can be made relatively large in the segment on the traveling direction side of the automobile in the axial direction of the cylinder. And the liquid working fluid can easily receive heat from the segment. In addition, the permeation speed when the liquid working fluid permeates the porous segment can be increased. As a result, the liquid working fluid can be easily evaporated, and the evaporation speed can be increased.

  Thus, by changing the pore diameter and / or the porosity of the porous segment in the axial direction of the cylinder, the evaporation rate of the liquid working fluid can be adjusted in the axial direction of the cylinder. Therefore, the evaporation speed of the working fluid can be leveled in the axial direction of the cylinder.

  Moreover, said wick may be equipped with the non-return valve arrange | positioned in the cylinder formed by the some segment. The check valve may be configured to allow the flow of fluid from one side to the other side in the axial direction of the cylinder and to prevent the flow of fluid from the other side to the one side.

  According to such a configuration, the check valve can prevent the liquid working fluid flowing in the cylinder from flowing backward. Thereby, the liquid working fluid can be reliably flowed to the back of the cylindrical body in the axial direction. Therefore, the evaporation speed of the working fluid can be leveled in the axial direction of the cylinder.

It is a figure which shows schematic structure of a heat pipe provided with the wick of an Example. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a figure which shows schematic structure of the wick of an Example. It is a figure which shows schematic structure of a loop heat pipe. It is a figure which shows schematic structure of the motor vehicle carrying a loop heat pipe. It is sectional drawing corresponding to FIG. 3 of another Example.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. As shown in FIGS. 1 to 3, the heat pipe 1 according to the embodiment includes a wick 2 and a case 3. The heat pipe 1 is a device that transfers heat using a working fluid.

  As shown in FIG. 4, the wick 2 includes a plurality of segments 22. A wick cylinder 21 is formed by the plurality of segments 22. The plurality of segments 22 are arranged side by side so as to form the wick cylinder 21. The plurality of segments 22 are arranged side by side in the circumferential direction of the wick cylinder 21. Each segment 22 is curved along the circumferential direction of the wick cylinder 21. The plurality of segments 22 are arranged side by side in the axial direction (x direction) of the wick cylinder 21. Each segment 22 extends along the axial direction (x direction) of the wick cylinder 21.

  The plurality of segments 22 are joined by the joining layer 5. The segment 22 and the segment 22 adjacent to each other in the circumferential direction of the wick cylinder 21 are joined by the joining layer 5. Further, the segment 22 and the segment 22 adjacent to each other in the axial direction of the wick cylinder 21 are joined by the joining layer 5. The bonding layer 5 is disposed between the end faces of the plurality of adjacent segments 22. The wick cylinder 21 is formed by integrally bonding the plurality of segments 22 with the bonding layer 5.

  The bonding layer 5 for bonding the plurality of segments 22 is preferably composed mainly of ceramics, and one or more colloidal sols such as silica sol or alumina sol, silicon carbide, silicon nitride, cordierite, alumina, mullite, One or more of inorganic powders such as ceramics selected from the group consisting of zirconia, zirconium phosphate, aluminum titanate, titania and combinations thereof, Fe-Cr-Al metal, nickel metal or metal Si and SiC, It is preferably formed by drying, heating, firing or the like from a raw material containing one or more inorganic fibers such as ceramic fibers and an inorganic binder. The colloidal sol is suitable for imparting adhesive force, and the inorganic powder is suitable for improving the affinity with the segment 22, and the inorganic powder has a thermal expansion value close to that of the main component of the segment 22. Is preferred. Further, the inorganic fiber is suitable as a reinforcing material that suitably imparts toughness to the bonding layer 5. In the case where an adhesive layer and an intermediate layer are provided in the bonding layer 5, appropriate components can be selected from the above components and used as components of the adhesive layer and / or the intermediate layer. The bonding layer 5 is formed by applying a bonding agent that is a raw material of the bonding layer 5 to the segment 22 and drying it. There is no restriction | limiting in particular in the method of apply | coating a bonding agent to the segment 22, For example, it can apply by the application | coating by a spray method, a brush, a brush, a dipping method, etc.

  A liquid channel 51 is formed on the inner side of the wick cylinder 21 constituted by a plurality of segments 22. A liquid working fluid flows through the liquid channel 51 in the wick cylinder 21. The wick cylinder 21 is formed in a substantially cylindrical shape, and the liquid channel 51 is also formed in a substantially cylindrical shape. The wick cylinder 21 may be formed in a substantially rectangular tube shape. The shape of the cylinder in the cross section orthogonal to the axial direction (x direction) of the wick cylinder 21 is not particularly limited.

  The liquid flow path 51 has one end portion (an inlet side of the liquid working fluid) in the axial direction of the wick cylinder 21 opened, and the other end portion sealed by the first sealing body 41. A liquid working fluid flows from the inlet 512 of the liquid channel 51. The first sealing body 41 is integrated with the wick cylinder 21.

  Grooves 23 are formed on the outer peripheral surface of each segment 22. A groove 23 formed in each of the plurality of segments 22 arranged in the axial direction of the wick cylinder 21 is connected to the axial direction of the wick cylinder 21. A gas flow path 52 is formed by a plurality of grooves 23 arranged in the axial direction of the wick cylinder 21. A gaseous working fluid flows through the groove 23. A plurality of grooves 23 are formed in the circumferential direction of the wick cylinder 21. The plurality of circumferential grooves 23 extend in the axial direction (x direction) of the wick cylinder 21. The plurality of circumferential grooves 23 extend from one end portion in the axial direction (x direction) of the wick cylinder 21 to the other end portion.

  The gas flow path 52 is sealed at one end in the axial direction of the wick cylinder 21 by a lid 31 of the case 3 described later. The other end of the gas flow path 52 (the outlet side of the gaseous working fluid) is open. A liquid working fluid flows out from the outlet 523 of the gas flow path 52.

  The wick 2 is arranged so that the axial direction of the wick cylinder 21 is orthogonal to the vertical direction. In the plurality of segments 22 adjacent to each other in the circumferential direction of the wick cylinder 21, the segment 22 positioned on the upper side in the vertical direction with respect to the other segment 22 and the segment 22 positioned on the lower side in the vertical direction with respect to the other segment 22 are provided. is there. In the example shown in FIG. 2, the segment 22a is located below the segment 22b in the vertical direction.

  The pressure of the liquid working fluid flowing through the liquid flow path 51 acts on the plurality of segments 22 constituting the wick cylinder 21. In the plurality of segments 22 adjacent to each other in the circumferential direction of the wick cylinder 21, the pressure of the working fluid with respect to the segment 22a on the lower side in the vertical direction becomes relatively high due to the influence of the gravity of the liquid, and the segment on the upper side in the vertical direction The pressure of the working fluid with respect to 22b becomes comparatively low. The pressure of the liquid working fluid acting on the segment 22 varies depending on the circumferential position of the wick cylinder 21.

  Further, as shown in FIG. 3, an acceleration α may be applied to the wick 2 in the axial direction of the wick cylinder 21. For example, when the heat pipe 1 is mounted on an automobile, acceleration α may be applied in the axial direction of the wick cylinder 21 due to the acceleration of the automobile. The plurality of segments 22 adjacent to each other in the axial direction of the wick cylinder 21 include a segment 22 located on the acceleration direction side with respect to the other segments 22 and a segment 22 located on the opposite side to the acceleration direction. In the example shown in FIG. 3, the segment 22w is located closer to the acceleration direction than the segment 22v.

  When acceleration is applied to the wick 2, force due to the acceleration acts on the working fluid of the liquid flowing in the liquid flow path 51 in the wick cylinder 21. In addition, the pressure of the liquid working fluid flowing in the liquid flow path 51 acts on the plurality of segments 22 constituting the wick cylinder 21. In the plurality of segments 22 adjacent to each other in the axial direction of the wick cylinder 21, the pressure of the working fluid on the segment 22v on the opposite side to the acceleration direction in the axial direction of the wick cylinder 21 becomes relatively high due to the influence of the force due to the acceleration. . On the other hand, the pressure of the working fluid on the segment 22w on the acceleration direction side in the axial direction of the wick cylinder 21 is relatively low. The pressure of the liquid working fluid acting on the segment 22 differs depending on the axial location of the wick cylinder 21.

  The plurality of segments 22 are made of a porous material such as ceramics. Therefore, a large number of pores are formed inside each segment 22. In the plurality of segments 22, the pore diameter and the porosity are different. The plurality of segments 22 adjacent in the circumferential direction of the wick cylinder 21 have different pore diameters and / or porosity. Further, the pore diameters and / or the porosity of the plurality of segments 22 adjacent in the axial direction of the wick cylinder 21 are different. The measuring method of a pore diameter and a porosity is not specifically limited, The well-known measuring method in a porous body can be used. For example, the pore diameter can be obtained by measuring the pore diameter distribution and calculating the average pore diameter. The pore diameter (average pore diameter) can be measured using a mercury intrusion method. The porosity can be measured using the Archimedes method. The porosity is obtained by calculating based on the saturated mass, dry mass, and underwater mass of the segment 22.

  In the plurality of segments 22 adjacent in the circumferential direction of the wick cylinder 21, the pore diameter of the upper segment 22 in the vertical direction is smaller than the pore diameter of the lower segment 22. Further, the porosity of the upper segment 22 in the vertical direction is larger than the porosity of the lower segment 22.

  In the plurality of segments 22 adjacent to each other in the axial direction of the wick cylinder 21, the pore diameter of the segment 22 on the inlet 512 side of the liquid channel 51 is smaller than the pore diameter of the segment 22 on the back side of the liquid channel 51. Further, the porosity of the segment 22 on the inlet 512 side of the liquid channel 51 is larger than the porosity of the segment 22 on the back side of the liquid channel 51.

  As shown in FIG. 3, the case 3 includes a case cylinder 32 and a pair of lids 31. The case cylinder 32 and the pair of lid bodies 31 are made of a metal material such as copper (Cu), for example. The case cylinder 32 is formed in a cylindrical shape. The case cylinder 32 may be formed in a square cylinder shape. The shape of the case cylinder 32 in the cross section orthogonal to the axial direction (x direction) of the case cylinder 32 is not particularly limited. The case cylinder 32 is disposed outside the wick cylinder 21. The case cylinder 32 covers the wick cylinder 21. The inner peripheral surface of the case cylinder 32 is in close contact with the outer peripheral surface of the wick cylinder 21. The pair of lids 31 are fixed to both ends of the case cylinder 32. The pair of lids 31 seals the case cylinder 32.

  A heat transfer device 80 is attached to the case 3. The heat transfer device 80 is fixed to the outer peripheral surface of the case 3. The heat transfer device 80 is a device that transfers heat to the case 3. Case 3 is heated by heat transfer device 80.

  Next, the loop heat pipe 101 including the heat pipe 1 will be described. As shown in FIG. 5, the loop heat pipe 101 includes an evaporator 111, a steam pipe 122, a condenser 112, and a liquid pipe 121. The evaporator 111, the steam pipe 122, the condenser 112, and the liquid pipe 121 are connected so as to form a loop. Further, the loop heat pipe 101 includes a reservoir 125.

  The evaporator 111 is configured by the heat pipe 1 described above. In the evaporator 111, the liquid working fluid is heated and evaporated, and the state changes to a gaseous working fluid. The working fluid receives heat in the evaporator 111. The evaporator 111 is a device that heats the working fluid.

  In the condenser 112, the gaseous working fluid is cooled and condensed, and the state changes to a liquid working fluid. The working fluid dissipates heat in the condenser 112. The condenser 112 is a device that receives heat from the working fluid.

  The liquid pipe 121 guides the liquid working fluid from the condenser 112 to the evaporator 111. The upstream end of the liquid pipe 121 is connected to the condenser 112, and the downstream end is connected to the evaporator 111. A liquid working fluid flows in the liquid pipe 121.

  The vapor pipe 122 guides the gaseous working fluid from the evaporator 111 to the condenser 112. The upstream end of the steam pipe 122 is connected to the evaporator 111, and the downstream end is connected to the condenser 112. A gaseous working fluid flows in the vapor pipe 122.

  The reservoir 125 is installed in the liquid pipe 121. A part of the liquid working fluid flowing through the liquid pipe 121 is stored. Thus, the flow rate of the liquid working fluid flowing from the liquid pipe 121 to the evaporator 111 is adjusted.

  Next, the operation of the loop heat pipe 101 will be described. In the loop heat pipe 101, the case 3 of the heat pipe 1 is heated, and the wick 2 is heated by the heat. In this state, the liquid working fluid that has flowed through the liquid pipe 121 is introduced from the liquid pipe 121 into the evaporator 111. That is, a liquid working fluid is introduced from the liquid pipe 121 to the heat pipe 1. The liquid working fluid introduced into the heat pipe 1 flows into the liquid channel 51 in the wick cylinder 21 and flows through the liquid channel 51. The liquid working fluid flowing through the liquid channel 51 permeates into the plurality of porous segments 22 constituting the wick cylinder 21 by capillary action.

  When the liquid working fluid penetrates into the porous segment 22, it receives heat from the segment 22 and evaporates, and changes its state to a gaseous working fluid. The evaporated working fluid flows into the gas flow paths 52 from the porous segment 22 and flows through the gas flow paths 52. The gaseous working fluid that has flowed through the gas flow path 52 flows out of the heat pipe 1 and flows into the steam pipe 122. That is, a gaseous working fluid flows into the vapor pipe 122 from the evaporator 111.

  The gaseous working fluid that has flowed into the steam pipe 122 flows through the steam pipe 122 and is introduced from the steam pipe 122 into the condenser 112. The gaseous working fluid introduced into the condenser 112 is condensed by releasing heat in the condenser 112, and changes to a liquid working fluid. The condensed liquid working fluid flows into the liquid pipe 121 from the condenser 112 and flows through the liquid pipe 121 again. Then, the liquid working fluid that has flowed through the liquid pipe 121 is again introduced into the heat pipe 1 from the liquid pipe 121. In this way, the working fluid flows through the loop heat pipe 101 while changing its state between the liquid and the gas. Heat is transported by the working fluid.

  Next, an example of usage of the loop heat pipe 101 will be described. The loop heat pipe 101 is used in, for example, an automobile. As shown in FIG. 6, the loop heat pipe 101 is mounted on the automobile 201. The automobile 201 is, for example, a gasoline automobile or a hybrid automobile. The loop heat pipe 101 is disposed in the engine room 202 of the automobile 201. The evaporator 111 (heat pipe 1) of the loop heat pipe 101 is disposed at a first position of the engine room 202 (for example, a position near the engine). Further, the condenser 112 of the loop heat pipe 101 is disposed at a second position of the engine room 202 (for example, a position in the vicinity of the radiator). Loop heat pipe 101 transports heat from a first position of engine room 202 to a second position.

  The evaporator 111 (heat pipe 1) of the loop heat pipe 101 is arranged so that the axial direction of the wick cylinder 21 is along the traveling direction (front-rear direction) of the automobile 201. Further, the evaporator 111 (heat pipe 1) is arranged so that the axial direction of the wick cylinder 21 is orthogonal to the vertical direction. Further, the evaporator 111 (heat pipe 1) is arranged such that the inlet 512 of the liquid channel 51 faces the front in the traveling direction of the automobile 201 and the outlet 523 of the gas passage 52 faces the rear of the traveling direction of the automobile 201. Yes.

  When the automobile 201 equipped with the loop heat pipe 101 starts, a force due to the acceleration of the automobile 201 acts on the liquid working fluid flowing in the liquid flow path 51. The force due to the acceleration of the automobile 201 acts on the side opposite to the traveling direction of the automobile 201.

  The heat pipe 1 including the wick 2, the loop heat pipe 101 including the heat pipe 1, and the usage mode of the loop heat pipe 101 have been described above. As is clear from the above description, the wick 2 according to the embodiment includes a plurality of porous segments 22 and the joining layer 5 that joins the segments 22 and the segments 22. A plurality of segments 22 are arranged side by side so as to form the wick cylinder 21, and the adjacent segments 22 and the segments 22 are joined by the joining layer 5.

  According to such a configuration, even if some force acts on the plurality of segments 22 forming the wick cylinder 21, the bonding layer 5 functions as a cushioning material, so that a large force is locally applied to each segment 22. It can suppress acting. For example, thermal stress when the wick 2 is heated may act on the plurality of segments 22 constituting the wick 2. In addition, for example, when the wick 2 is mounted on the automobile 201, a force due to the acceleration of the automobile 201 may act on the plurality of segments 22. Further, gravity acts on each of the plurality of segments 22. As described above, various forces act on the plurality of segments 22. However, when the bonding layer 5 functions as a cushioning material, it is possible to suppress a large force from acting locally on each segment 22. Therefore, even if the wick 2 is composed of a plurality of segments 22, it is possible to prevent the segments 22 from being damaged.

  Moreover, in said wick 2, the some segment 22 is arrange | positioned along with the circumferential direction of the wick cylinder 21, and the pore diameter and / or porosity of the segment 22 adjacent to the circumferential direction differ.

  According to such a configuration, the evaporation speed of the liquid working fluid can be leveled in the circumferential direction of the wick cylinder 21. More specifically, for example, as shown in FIGS. 1 to 3, when the wick 2 is arranged so that the axial direction of the wick cylinder 21 is perpendicular to the vertical direction, the lower part of the wick cylinder 21 in the circumferential direction In the segment 22a, the pressure of the liquid working fluid with respect to the segment 22a becomes relatively high due to the gravity of the liquid working fluid flowing through the liquid flow path 51. On the other hand, in the segment 22b at the upper part in the circumferential direction of the wick cylinder 21 than the segment 22a, the pressure of the liquid working fluid is relatively low. In this way, the pressure of the liquid working fluid acting on the segment 22 may differ depending on the circumferential location of the wick cylinder 21. Due to such a pressure difference, in the segment 22a at the lower portion in the circumferential direction of the wick cylinder 21, the liquid working fluid permeates the porous segment 22a relatively quickly, and the evaporation speed of the working fluid becomes relatively fast. Tend. On the other hand, in the segment 22b at the upper portion in the circumferential direction of the wick cylinder 21 than the lower segment 22a, the liquid working fluid penetrates into the porous segment 22b relatively slowly. Therefore, the evaporation rate of the liquid working fluid tends to be relatively slow. Therefore, the evaporation speed of the liquid working fluid tends to be non-uniform in the circumferential direction of the wick cylinder 21.

  Therefore, for example, in the porous segment 22a at the lower portion in the circumferential direction of the wick cylinder 21, the pore diameter is increased and the porosity is decreased. According to such a configuration, in the segment 22a at the lower portion in the circumferential direction of the wick cylinder 21, when the liquid working fluid permeates the segment 22a, the contact area between the working fluid and the segment 22a can be reduced. The liquid working fluid can hardly receive heat from the segment 22a. In addition, the permeation speed when the liquid working fluid permeates the porous segment 22a can be reduced. As a result, the liquid working fluid can hardly be evaporated, and the evaporation speed can be reduced. On the other hand, in the porous segment 22b at the upper part in the circumferential direction of the wick cylinder 21, the pore diameter is reduced and the porosity is increased. According to such a configuration, the contact area between the working fluid and the segment 22b can be increased when the liquid working fluid penetrates the segment 22b in the segment 22b at the upper portion in the circumferential direction of the wick cylinder 21. The liquid working fluid can easily receive heat from the segment 22b. In addition, the penetration speed when the liquid working fluid penetrates into the porous segment 22b can be increased. As a result, the liquid working fluid can be easily evaporated, and the evaporation speed can be increased. In this way, by setting the pore diameter and / or the porosity of the segments 22 adjacent in the circumferential direction of the wick cylinder 21 to be different, the evaporation rate of the liquid working fluid is adjusted in the circumferential direction of the wick cylinder 21. can do. Therefore, the evaporation rate of the liquid working fluid can be leveled in the circumferential direction of the wick cylinder 21.

  Moreover, in said wick 2, the some segment 22 is arrange | positioned along with the axial direction of the wick cylinder 21, and the pore diameter and / or porosity of the segment 22 adjacent to an axial direction differ.

  According to such a configuration, the evaporation speed of the liquid working fluid can be leveled in the axial direction of the wick cylinder 21. More specifically, for example, as shown in FIG. 6, when the loop heat pipe 101 is mounted on the automobile 201 and the automobile 201 starts, the force due to the acceleration of the automobile 201 acts on the liquid working fluid relatively. . The force due to the acceleration of the automobile 201 acts in the axial direction of the wick cylinder 21. At this time, in the segment 22v on the opposite side of the moving direction of the automobile 201 in the axial direction of the wick cylinder 21, the pressure of the liquid working fluid on the segment 22v increases due to the influence of the force due to acceleration. On the other hand, in the segment 22w on the traveling direction side of the automobile 201 in the axial direction of the wick cylinder 21, the pressure of the liquid working fluid is relatively low. Thus, the pressure of the liquid working fluid acting on the segment 22 may differ depending on the axial position of the wick cylinder 21. Due to such a pressure difference, in the segment 22v on the opposite side of the traveling direction of the automobile 201 in the axial direction of the wick cylinder 21, the liquid working fluid permeates the porous segment 22v relatively quickly, and the working fluid The evaporation rate tends to increase. On the other hand, in the segment 22w on the traveling direction side of the automobile 201 in the axial direction of the wick cylinder 21, the liquid working fluid penetrates into the porous segment 22w relatively slowly, and the evaporation speed of the working fluid tends to be slow. .

  Therefore, for example, in the segment 22v on the side opposite to the traveling direction of the automobile 201 in the axial direction of the wick cylinder 21, the pore diameter is increased and the porosity is decreased. According to such a configuration, in the segment 22v on the opposite side of the traveling direction of the automobile in the axial direction of the wick cylinder 21, when the liquid working fluid permeates the segment 22v, the contact area between the working fluid and the segment 22v And the liquid working fluid can hardly receive heat from the segment 22v. In addition, the permeation speed when the liquid working fluid permeates the porous segment 22v can be reduced. As a result, the liquid working fluid can hardly be evaporated, and the evaporation speed can be reduced. On the other hand, in the segment 22w on the traveling direction side of the automobile 201 in the axial direction of the wick cylinder 21, the pore diameter is reduced and the porosity is increased. According to such a configuration, in the segment 22w on the traveling direction side of the automobile 201 in the axial direction of the wick cylinder 21, when the liquid working fluid permeates the segment 22w, the contact area between the working fluid and the segment 22w is increased. The liquid working fluid can be made relatively large and can easily receive heat from the segment 22w. Further, the permeation speed when the liquid working fluid permeates the porous segment 22w can be increased. As a result, the liquid working fluid can be easily evaporated, and the evaporation speed can be increased. In this way, by setting the pore diameter and / or the porosity of the segments 22 adjacent in the axial direction of the wick cylinder 21 to be different, the evaporation rate of the liquid working fluid is adjusted in the axial direction of the wick cylinder 21. can do. Therefore, the evaporation rate of the liquid working fluid can be leveled in the axial direction of the wick cylinder 21.

  Although one embodiment has been described above, the specific mode is not limited to the above embodiment. In the following description, the same components as those described above are denoted by the same reference numerals and description thereof is omitted.

  In the above embodiment, the pore diameters and / or the porosity of the plurality of adjacent segments 22 are different from each other. However, the configuration is not limited to this configuration, and the pore distribution is further different. May be.

  In still another embodiment, the wick 2 may include a first check valve 61 and a second check valve 62 as shown in FIG. The first check valve 61 and the second check valve 62 are disposed in the liquid flow path 51 in the wick cylinder 21. The first check valve 61 and the second check valve 62 are fixed to the inner peripheral surface of the wick cylinder 21. The first check valve 61 and the second check valve 62 are formed integrally with the wick cylinder 21. The first check valve 61 is disposed closer to the inlet 512 of the liquid flow channel 51 than the second check valve 62. The second check valve 62 is disposed on the back side of the liquid flow channel 51 with respect to the first check valve 61. Each of the first check valve 61 and the second check valve 62 is fixed to the segment 22 in the corresponding position.

  The first check valve 61 and the second check valve 62 regulate the flow of the liquid working fluid flowing through the liquid flow path 51. The first check valve 61 and the second check valve 62 allow the liquid working fluid to flow from one side to the other side in the axial direction (x direction) of the wick cylinder 21. The first check valve 61 and the second check valve 62 block the flow of the liquid working fluid from the other side in the axial direction (x direction) of the wick cylinder 21 to the one side. In the example shown in FIG. 7, the first check valve 61 and the second check valve 62 allow the liquid working fluid to flow from the inlet 512 side to the back side of the liquid channel 51. The first check valve 61 and the second check valve 62 block the flow of the liquid working fluid from the back side of the liquid flow path 51 to the inlet 512 side. The form of the first check valve 61 and the second check valve 62 is not particularly limited as long as the flow of the liquid working fluid can be regulated.

  According to such a configuration, the first check valve 61 and the second check valve 62 allow the liquid working fluid flowing through the liquid flow path 51 from the inlet 512 side to the back side to be on the opposite side (from the back side to the inlet 512 side). ) Can be prevented from flowing backward. As a result, the liquid working fluid can surely flow to the back of the liquid channel 51. Therefore, the evaporation rate of the liquid working fluid can be leveled in the axial direction of the wick cylinder 21.

  In the above embodiment, the wick 2 includes the first check valve 61 and the second check valve 62. However, the present invention is not limited to this configuration, and the first check valve 61 and the second check valve are not limited thereto. The structure provided only with any one of 62 may be sufficient.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

1: Heat pipe 2: Wick 3: Case 5: Bonding layer 21: Wick cylinder 22: Segment 23: Groove 31: Lid 32: Case cylinder 41: First sealing body 42: Second sealing body 51: Liquid channel 52: Gas channel 61: First check valve 62: Second check valve 80: Heat transfer device 101: Loop heat pipe 111: Evaporator 112: Condenser 121: Liquid pipe 122: Steam pipe 125: Reservoir 201: Automobile 202: Engine room 512: Entrance 523: Exit

Claims (4)

A heat pipe wick,
A plurality of porous segments;
The segment and a bonding layer for bonding the segment,
The wick, wherein the plurality of segments are arranged side by side so as to form a cylindrical body, and the adjacent segments and the segments are joined by the joining layer.   The wick according to claim 1, wherein the plurality of segments are arranged side by side in the circumferential direction of the cylindrical body, and the pore diameter and / or porosity of the segments adjacent in the circumferential direction are different.   The wick according to claim 1 or 2, wherein the plurality of segments are arranged side by side in the axial direction of the cylindrical body, and the pore diameters and / or the porosity of the segments adjacent in the axial direction are different. Comprising a check valve disposed in the cylinder formed by the plurality of segments;
4. The check valve according to claim 1, wherein the check valve allows a fluid flow from one side to the other side in the axial direction of the cylindrical body and blocks a fluid flow from the other side to the one side. Wick described in crab.

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