WO2017212652A1

WO2017212652A1 - Wick

Info

Publication number: WO2017212652A1
Application number: PCT/JP2016/067438
Authority: WO
Inventors: 博治小林; 三輪　真一; 宏之柴田
Original assignee: 日本碍子株式会社
Priority date: 2016-06-10
Filing date: 2016-06-10
Publication date: 2017-12-14
Also published as: JPWO2017212652A1; JP6715925B2

Abstract

A wick 2 that is for a heat pipe 1 and that comprises: a porous cylindrical body 21; and a plurality of porous wall bodies 22 that extend through an internal space 70 of the cylindrical body 21 in the axial direction of the cylindrical body 21 and partition the internal space 70. Liquid flow paths 51 and gas flow paths 52 that extend in the axial direction are formed in the internal space 70 as a result of the plurality of wall bodies 22 partitioning the internal space 70. The liquid flow paths 51 are open at one end in the axial direction and sealed at the other end. The gas flow paths 52 are sealed at the one end in the axial direction and open at the other end.

Description

Wick

The technology disclosed in this specification relates to a heat pipe wick.

The heat pipe disclosed in Patent Document 1 (Japanese Unexamined Patent Publication No. 2011-190996) includes a wick and a case. The wick and the case are formed in a cylindrical shape. The wick is made of a porous material, and the case is made of 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.

In the heat pipe, it is preferable to efficiently heat the liquid working fluid to change the state to a gaseous working fluid. For this purpose, it is preferable to efficiently transfer heat from the wick to the liquid working fluid. Conventional heat pipes are insufficient in this respect. Therefore, the present specification provides a technique capable of efficiently transferring heat to a liquid working fluid.

A heat pipe wick disclosed in the present specification includes a porous cylinder and a plurality of porous walls extending in the axial direction of the cylinder in the internal space of the cylinder and partitioning the internal space. ing. A plurality of wall bodies partition the internal space, so that a liquid channel and a gas channel extending in the axial direction are formed in the internal space. The liquid channel has one end in the axial direction opened and the other end sealed. The gas flow path is sealed at one end in the axial direction and opened at the other end.

According to such a configuration, since the porous wall body that forms the liquid flow path and the gas flow path is provided in the internal space of the cylindrical body, the working fluid of the liquid flowing through the liquid flow path is liquid by capillary action. It penetrates into the wall from the channel. The liquid working fluid that has permeated the wall body receives heat from the wall body, evaporates, and changes its state to a gaseous working fluid. The evaporated working fluid flows from the wall into the gas flow path and flows through the gas flow path. According to such a configuration, since the wall body is provided, the portion where the liquid working fluid contacts the wick increases, and the portion that can receive heat from the wick increases. Therefore, heat can be efficiently transferred to the liquid working fluid.

In the above wick, the cross-sectional area of the liquid channel may be larger than the cross-sectional area of the gas channel in the cross section perpendicular to the axial direction of the cylinder.

According to such a configuration, the resistance when the liquid working fluid flows through the liquid flow path can be reduced.

Further, the liquid flow path is surrounded by a plurality of wall bodies and does not have to be in contact with the cylinder body.

According to such a configuration, heat can be efficiently transferred from the wall body to the liquid working fluid flowing in the liquid flow path.

It is a figure which shows schematic structure of a heat pipe provided with the wick of an Example. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a sectional view taken along the line III-III in FIG. 2. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a figure which shows schematic structure of a loop heat pipe. It is sectional drawing corresponding to FIG. 4 of another Example. Furthermore, it is sectional drawing corresponding to FIG. 4 of another Example. It is sectional drawing of the liquid flow path and gas flow path of another Example. Furthermore, it is sectional drawing corresponding to FIG. 4 of another Example. Furthermore, it is sectional drawing corresponding to FIG. 4 of another Example.

Hereinafter, examples 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.

The wick 2 includes a wick cylinder 21 and a plurality of wall bodies 22. The wick cylinder 21 is made of a porous material such as ceramics. An internal space 70 is formed inside the wick cylinder 21. The wick cylinder 21 is formed in a cylindrical shape. Therefore, the internal space 70 is also formed in a cylindrical shape.

The plurality of wall bodies 22 are formed of a porous material such as ceramics, for example, similarly to the wick cylinder 21. The plurality of wall bodies 22 are arranged in the cylindrical internal space 70 of the wick cylinder 21. As shown in FIG. 2, in the cross section orthogonal to the axial direction (x direction) of the wick cylinder 21, a plurality of wall bodies 22 arranged at equal intervals in the horizontal direction (y direction) and the vertical direction (z direction) There are a plurality of wall bodies 22 arranged at equal intervals. In the cross section orthogonal to the axial direction (x direction) of the wick cylinder 21, both end portions of each wall body 22 are fixed to the inner peripheral surface of the wick cylinder 21. The plurality of wall bodies 22 and the wick cylinder 21 are integrally formed to form a honeycomb structure. The plurality of wall bodies 22 arranged in the horizontal direction and the vertical direction are combined in a lattice shape and are integrally formed.

The plurality of wall bodies 22 divide the internal space 70 of the wick cylinder 21 in directions (y direction and z direction) orthogonal to the axial direction (x direction) of the wick cylinder 21. The plurality of wall bodies 22 divide the internal space 70, so that a plurality of liquid flow paths 51 and a plurality of gas flow paths 52 are formed in the internal space 70. In the example shown in FIG. 2, four liquid channels 51 and twelve gas channels 52 are formed. A plurality of liquid flow paths 51 are formed at the center of the internal space 70, and a plurality of gas flow paths 52 are formed at the peripheral edge of the internal space 70. A plurality of liquid flow paths 51 are formed inside the plurality of gas flow paths 52. In the example shown in FIG. 2, each of the four inner spaces constitutes a liquid flow path 51, and each of the twelve outer spaces constitutes a gas flow path 52. A liquid working fluid flows through the liquid channel 51, and a gas working fluid flows through the gas channel 52.

In the cross section orthogonal to the axial direction of the wick cylinder 21, the liquid flow path 51 is surrounded by the plurality of wall bodies 22 and is in contact with the plurality of wall bodies 22. The liquid flow path 51 is not in contact with the wick cylinder 21. The gas flow path 52 is surrounded by the plurality of wall bodies 22 and the wick cylinder body 21, and is in contact with the plurality of wall bodies 22 and the wick cylinder body 21. Of the plurality of wall bodies 22, the wall body 22 arranged in the central portion of the internal space 70 is referred to as a central wall body 22 a. The central wall 22a passes through the central portion of the internal space 70.

As shown in FIG. 3, the plurality of wall bodies 22 extend in the axial direction (x direction) in a cross section parallel to the axial direction (x direction) of the wick cylinder 21. The plurality of wall bodies 22 extend from one end portion in the axial direction (x direction) of the wick cylinder 21 to the other end portion. The plurality of liquid channels 51 and the plurality of gas channels 52 extend in the axial direction (x direction). The plurality of liquid channels 51 and the plurality of gas channels 52 extend from one end of the wick cylinder 21 in the axial direction (x direction) to the other end. The liquid flow channel 51 is open at one end in the axial direction of the wick cylinder 21 and is sealed at the other end by the first sealing body 41. In the gas flow path 52, one end portion in the axial direction of the wick cylinder 21 is sealed by the second sealing body 42, and the other end portion is opened. As shown in FIG. 4, a plurality of liquid flow paths 51 are closed at the other axial end of the wick cylinder 21 (the liquid working fluid outlet side). On the other hand, although not shown, the plurality of gas flow paths 52 are closed at one end of the wick cylinder 21 in the axial direction (the inlet side of the liquid working fluid). The first sealing body 41 and the second sealing body 42 are integrated with the wick cylinder 21 and the plurality of wall bodies 22.

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.

The 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 constituted 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 steam 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. Therefore, the wick cylinder 21 and the wall 22 of the wick 2 are heated. 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 plurality of liquid flow paths 51 formed in the internal space 70 of the wick cylinder 21 and flows through the liquid flow path 51. The liquid working fluid flowing through the liquid channel 51 penetrates into the porous wall body 22 by capillary action.

When the liquid working fluid penetrates into the porous wall body 22, it receives heat from the wall body 22 and evaporates, and changes its state to a gaseous working fluid. The evaporated working fluid flows into the plurality of gas flow paths 52 from the porous wall body 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 into the condenser 112 from the steam pipe 122. 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.

As is clear from the above description, the wick 2 according to the embodiment includes the porous wall body 22 that forms the liquid channel 51 and the gas channel 52 in the internal space 70 of the wick cylinder 21. As a result, the liquid working fluid flowing through the liquid channel 51 permeates from the liquid channel 51 into the porous wall body 22 by capillary action. The liquid working fluid that has permeated the wall body 22 receives heat from the wall body 22 and evaporates, and changes its state to a gaseous working fluid. The evaporated working fluid flows into the gas channel 52 from the porous wall body 22 and flows through the gas channel 52. According to such a configuration, since the portion where the liquid working fluid is in contact with the wick 2 is increased by providing the wall body 22, the liquid working fluid can easily receive heat from the wick 2. Thereby, heat can be efficiently transferred from the wick 2 to the liquid working fluid.

Further, according to the above configuration, the liquid flow path 51 is surrounded by the plurality of wall bodies 22 and is not in contact with the wick cylinder 21, so that the wall body against the liquid working fluid flowing through the liquid flow path 51. The heat can be efficiently transferred from 22.

As mentioned above, although one Example was described, a specific aspect is not limited to the said Example. 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 plurality of liquid flow paths 51 are formed in the central portion of the internal space 70 and the plurality of gas flow paths 52 are formed in the peripheral edge of the internal space 70. However, the present invention is limited to this configuration. It is not something. In another embodiment, as shown in FIG. 6, the liquid channel 51 and the gas channel 52 may be alternately formed in a cross section orthogonal to the axial direction (x direction) of the wick cylinder 21. The plurality of liquid channels 51 and the plurality of gas channels 52 may be formed in a checkered pattern. Moreover, as shown in FIG. 7, in the cross section orthogonal to the axial direction (x direction) of the wick cylinder 21, a plurality of liquid flow paths 51 and a plurality of gas flow paths 52 are alternately formed for each row. Also good.

Further, as shown in FIG. 8, the cross-sectional area of each liquid channel 51 may be larger than the cross-sectional area of each gas channel 52 in a cross section orthogonal to the axial direction (x direction) of the wick cylinder 21. Further, the total cross-sectional area of the plurality of liquid flow paths 51 may be larger than the total cross-sectional area of the plurality of gas flow paths 52. According to such a configuration, the resistance when the liquid working fluid flows through the liquid channel 51 can be reduced. Since the liquid working fluid flows smoothly, the working fluid can be efficiently introduced into the wick 2.

In the above embodiment, the wick cylinder 21 is formed in a cylindrical shape, but is not limited to this configuration. The shape of the wick cylinder 21 in the cross section orthogonal to the axial direction (x direction) of the wick cylinder 21 is not particularly limited. In another embodiment, as shown in FIG. 9, the wick cylinder 21 may be formed in a square cylinder shape. In FIG. 9, the shape of the cross section orthogonal to the axial direction (x direction) of the wick cylinder 21 is a rectangle. A heat transfer device 80 is fixed to the upper surface of the wick cylinder 21. In the cross section shown in FIG. 9, the wick cylinder 21 is formed so that the upper side and the lower side of the wick cylinder 21 are longer than the side. The upper side and the lower side of the wick cylinder 21 are long sides, and the side sides are short sides. According to such a configuration, the area when heat is transmitted from the heat transfer device 80 to the wick cylinder 21 can be increased, and heat can be easily transmitted. Moreover, since the length of the wick cylinder 21 in the vertical direction is short, heat can be quickly transferred in the vertical direction via the wall body 22.

In still another embodiment, as shown in FIG. 10, the plurality of wall bodies 22 may be arranged concentrically and radially in a cross section orthogonal to the axial direction of the wick cylinder 21. In the cross section shown in FIG. 10, the plurality of wall bodies 22 arranged concentrically are arranged concentrically with the wick cylinder 21. The plurality of wall bodies 22 extend in the circumferential direction of the wick cylinder 21. In the cross section shown in FIG. 10, the plurality of wall bodies 22 arranged radially extend from the center of the internal space 70 in the radial direction of the wick cylinder 21. In the plurality of radial walls 22, heat is quickly transmitted to the center of the internal space 70.

Next, an example of a manufacturing method of the wick 2 will be described. When the wick 2 is manufactured, first, water and a binder are added to the ceramic raw material powder and kneaded to prepare a kneaded clay having plasticity. Next, the prepared dough is extruded to form a honeycomb structure. As a result, a honeycomb structure including the wick cylinder 21 and the plurality of wall bodies 22 is formed.

Next, a sheet is attached to one end face of the honeycomb structure, and a hole is made in a part of the sheet (a position corresponding to the end of the gas flow path 52). In this state, one end surface of the honeycomb structure is immersed in a slurry containing a material of the sealing body (the first sealing body 41 and the second sealing body 42 described above). Thereafter, the material of the sealing body is cured by drying and baking, whereby the second sealing body 42 that seals the end of the gas flow path 52 is formed. Similarly to the above, a sheet is attached to the other end surface of the honeycomb structure, and a hole is formed in a part of the sheet (a position corresponding to the end of the liquid flow channel 51). In this state, the other end surface of the honeycomb structure is immersed in a slurry containing the material of the sealing body. Then, the 1st sealing body 41 which seals the edge part of the liquid flow path 51 is formed by hardening the material of a sealing body by drying and baking. In addition, each of the one end surface and the other end surface of the honeycomb structure is immersed in a slurry containing the material of the sealing body, and then dried and fired, whereby the second sealing body 42 and the first sealing body. 41 may be formed simultaneously.

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 21: Wick cylinder 22: Wall body 22a: Central wall body 31: Cover body 32: Case cylinder 41: First sealing body 42: Second sealing body 51 : Liquid channel 52: Gas channel 70: Internal space 80: Heat transfer device 101: Loop heat pipe 111: Evaporator 112: Condenser 121: Liquid pipe 122: Steam pipe 125: Reservoir

Claims

A heat pipe wick,
A porous cylinder;
A plurality of porous walls that extend in the axial direction of the cylinder in the internal space of the cylinder and partition the internal space;
A liquid channel and a gas channel extending in the axial direction by the plurality of wall bodies partitioning the internal space are formed in the internal space,
The liquid channel has one end in the axial direction opened and the other end sealed.
The gas flow path is a wick in which one end portion in the axial direction is sealed and the other end portion is open.
The wick according to claim 1, wherein a cross-sectional area of the liquid channel is larger than a cross-sectional area of the gas channel in a cross section orthogonal to the axial direction.
The wick according to claim 1 or 2, wherein the liquid channel is surrounded by a plurality of the wall bodies and is not in contact with the cylindrical body.