JP7458243B2 - Heat Transport Devices - Google Patents

Description

The present invention relates to a heat transport device, and more specifically, to a heat transport device that reliably transports a working fluid whose phase has changed to a liquid phase working fluid through condensation to an evaporation section where the phase change is performed to a gas phase working fluid. Relating to transportation devices.

With the increasing functionality of electronic devices in recent years, heating elements such as electrical and electronic components (hereinafter simply referred to as "heating elements") are mounted in a high density inside electronic devices. The amount of heat generated tends to increase. If the temperature of the heating element rises above a predetermined permissible temperature, it may cause the heating element to malfunction, so it is necessary to maintain the temperature of the heating element at or below the permissible temperature at all times. Therefore, a heat transport device for transporting the heat of a heating element to the outside is usually mounted inside an electronic device. Such heat transport devices include, for example, an evaporator that evaporates a liquid-phase working fluid to change its phase to a gas-phase working fluid, and an evaporator that condenses a gas-phase working fluid to change its phase to a liquid-phase working fluid. Vapor chambers and heat pipes are known that are equipped with a condensing section to transport latent heat (heat of vaporization) to the outside by changing the phase of a working fluid.

BACKGROUND ART Heat generating elements such as electrical and electronic components that constitute electronic equipment tend to generate more heat as described above, and therefore there is a need to further improve the heat transport performance of heat transport devices. To further improve the heat transport performance of a heat transport device, it is useful to facilitate the circulation of a working fluid inside the heat transport device.

As a means for smoothing the circulation of a working fluid inside a heat transport device, for example, Patent Document 1 discloses that a groove is formed in the inner wall of a tube body, and a capillary force is applied so as to tightly fit inside the groove. Heat transport devices (coolers) loaded with fibrous bodies consisting of fine fibers are described. In this heat transport device, by loading the fibrous body inside the groove formed on the inner wall of the tube body, in addition to the capillary force of the groove, the fibers contained in the fibrous body exert a strong capillary force. It is said that the hydraulic fluid can be moved reliably without being affected by the

Japanese Patent Application Publication No. 2013-100977

However, in the heat transport device of Patent Document 1, the liquid phase working fluid permeates into the fibrous body, so in the intermediate portion located between the evaporation section and the condensation section, the gas phase working fluid and the liquid phase working fluid are mixed. Fluid flows in opposite directions are formed in the same internal space.

Therefore, the liquid-phase working fluid collides with the gas-phase working fluid, which tends to cause turbulence in the flow of the fluid, and as a result, there is a problem in that the desired heat transport efficiency cannot be obtained.

An object of the present invention is to provide a heat transport device with improved heat transport performance.

In order to achieve the above object, the gist of the present invention is as follows.
(1) An evaporation section that has a working fluid inside the container and evaporates the working fluid; a condensation section that is arranged at a position separated from the evaporation section and that condenses the working fluid; and the evaporation section and an intermediate section disposed between the condensing section and the condensing section, wherein the container has an inner peripheral surface continuously extending from the condensing section through the intermediate section to the evaporating section. at least one groove located in the intermediate portion, and the groove has an opening groove width narrower than that of the groove located in the evaporation portion or the condensation portion, or the groove is located in the intermediate portion. A heat transport device in which the opening of the groove located at is closed.
(2) The heat transport device according to (1) above, wherein the opening groove width when measured at the opening position of the groove portion located in the intermediate portion is in a range of 0 μm or more and 300 μm or less.
(3) The heat transport device according to (1) or (2), wherein the width of the groove portion located in the intermediate portion is configured to increase in the groove depth direction from the opening position.
(4) Any one of (1) to (3) above, wherein the groove depth of the groove portion that continuously extends from the condensation section to the evaporation section via the intermediate section is in the range of 100 μm or more and 2000 μm or less. The heat transport device according to item 1.
(5) The groove portion located in the intermediate portion has a ratio of groove depth to opening groove width in the range of 0.5 or more and 50 or less when viewed in a cross section of the container, from (1) to (4) above. ) The heat transport device according to any one of the above.
(6) The heat transport device according to any one of (1) to (5) above, wherein the groove has a porous layer formed on an inner surface of the groove portion located in the evaporation section.
(7) The at least one groove is a plurality of grooves, and the plurality of grooves are arranged parallel to each other at intervals on the surface of the container, and the intervals are 200 μm or more and 1000 μm or less. The heat transport device according to any one of (1) to (6) above, wherein the heat transport device is in the range of (1) to (6).
(8) The heat transport device according to any one of (1) to (7) above, wherein the container is made of copper or a copper alloy.
(9) The container according to any one of (1) to (8) above, wherein the internal space is constituted by two metal sheets sealed at the ends and is used as a vapor chamber. transportation device.
(10) The heat transport device according to any one of (1) to (8) above, wherein the container has an internal space formed by a tubular container sealed at an end and is used as a heat pipe.

According to the present invention, a heat transport device with improved heat transport performance can be provided.

FIG. 1A is a plan view showing the internal structure of a vapor chamber that is a heat transport device of the first embodiment. FIG. 1B is a diagram showing the internal structure of a vapor chamber that is a heat transport device of the first embodiment, and is a cross-sectional view taken along line I _A - _{I A} in FIG. 1A. FIG. 1C is a diagram showing the internal structure of the vapor chamber that is the heat transport device of the first embodiment, and is a cross-sectional view taken along line I _B - I _B in FIG. 1A. FIG. 1D is a diagram showing the internal structure of a vapor chamber that is a heat transport device of the first embodiment, and is a cross-sectional view taken along line I _C - I _C in FIG. 1A. FIG. 2 is a transparent plan view showing the internal structure of the heat transport device to explain the flow of the working fluid that occurs in the vapor chamber of FIGS. 1A to 1C. FIG. 3 is a diagram showing the internal structure of a modified example of the vapor chamber that is the heat transport device of the first embodiment, in which FIG. 3(a) is a plan view, and FIG. 3(b) is a plan view of FIG. 3(a). FIG. 2 is a cross-sectional view taken along line II _A - II _A of FIG. FIG. 4 is a diagram showing the internal structure of a heat pipe, which is a heat transport device according to a third embodiment, in which FIG. 4(a) is a vertical cross-sectional view, and FIG. _A -III _A cross-sectional view when cut on line A, FIG. 4(c) is a cross-sectional view when cut on III _B -III _B line in FIG. 4(a), and FIG. 4(d) is FIG. 4(a) FIG. 2 is a cross-sectional view taken along line _IIIC - _IIIC of FIG.

Next, heat transport devices according to some embodiments of the present invention will be described below.

<First embodiment>
FIG. 1A is a plan view showing the internal structure of a vapor chamber that is a heat transport device of the first embodiment. FIG. 1B is a diagram showing the internal structure of a vapor chamber that is a heat transport device of the first embodiment, and is a cross-sectional view taken along line I _A - _{I A} in FIG. 1A. FIG. 1C is a diagram showing the internal structure of the vapor chamber that is the heat transport device of the first embodiment, and is a cross-sectional view taken along line I _B - I _B in FIG. 1A. FIG. 1D is a diagram showing the internal structure of a vapor chamber that is a heat transport device of the first embodiment, and is a cross-sectional view taken along line I _C - I _C in FIG. 1A. FIG. 2 is a plan view of the heat transport device to explain the flow of working fluid that occurs in the vapor chamber of FIGS. 1A to 1C.

As shown in FIG. 1A, the heat transport device 1 of the present invention has a working fluid F inside a container 2, an evaporation section 3 for evaporating the working fluid F, and a position separated from the evaporation section 3. This is a heat transport device that is provided with a condensing section 4 which is disposed in the evaporating section 3 and the condensing section 4 and which condenses the working fluid F, and an intermediate section 5 which is disposed between the evaporating section 3 and the condensing section 4. Here, the container 2 is provided with at least one groove 6 on the inner circumferential surface 2a that continuously extends from the condensing section 4 to the evaporating section 3 via the intermediate section 5, and the groove 6 is formed in a cross section of the container 2. The opening groove width _w1 of the groove located in the intermediate part 5 is narrower than the opening groove width of the groove located in the evaporating part 3 or the condensing part 4, or the opening of the groove located in the intermediate part 5 is closed.

As a result, as shown in FIG. 2, in the intermediate portion 5, the fluid flow of the gas-phase working fluid F(g) and the fluid flow of the liquid-phase working fluid F(L) are in opposite directions. However, in this embodiment, the opening groove width _w1 is relatively narrow or limited to the portion of the groove 6 where the opening is closed, so that the gas phase working fluid F( g) and the liquid-phase working fluid F(L) have a smaller contact area. Therefore, the phase change to the liquid phase that occurs when the gas phase working fluid F (g) is cooled by the liquid phase working fluid F (L) in these contacting parts is reduced, and the gas phase changes. It is possible to suppress a decrease in heat transport performance due to a phase change of the working fluid F(g). In addition, in the heat transport device 1 of the present invention, the opening groove width w _{1 of the groove portion located in the intermediate portion 5 can be configured to be narrow by simply performing press processing after laser processing the plate material to form the groove 6} . Therefore, the heat transport device 1 can be manufactured with fewer man-hours. Therefore, it is possible to provide a heat transport device that can be manufactured with fewer man-hours and has improved heat transport performance.

Note that the working fluid F exists in the heat transport device 1 in a phase-changed state between a liquid phase state and a gas phase state. Therefore, in the following description, for convenience of explanation, the liquid phase working fluid may be designated as F(L) and the gas phase working fluid as F(g).

(Heat transport device)
The heat transport device 1 has a configuration capable of transporting heat through a working fluid F sealed in an internal space S of a container 2, and is capable of transporting heat through various heat transfer devices such as a vapor chamber, a heat pipe, and a heat exchanger. It can be used for devices. In particular, the heat transport device 1 according to this embodiment is used as a vapor chamber, as shown in FIG. 1A.

(container)
The container 2 used in the heat transport device 1 has a working fluid F therein. More specifically, the container 2 has an internal space S in which the working fluid F is sealed. In particular, in this embodiment, the interior space S of the container 2 is formed by two metal sheets that are sealed at the ends T.

Here, one of the two metal sheets constitutes the heat transfer member 21 and the other constitutes the lid 22, and the upper surface of the heat transfer member 21 and the lower surface of the lid 22 are located at the end T of the container 2. Configured to be sealed. The heat transfer member 21 and the lid 22 may have the same structure. When these have the same structure, of the heat transfer member 21 and the lid 22, the one on the lower side becomes the heat transfer member 21, and the one on the upper side becomes the lid 22.

The internal space S of the container 2 in which the heat transport device 1 is provided is a space that is sealed from the external environment, and is depressurized by degassing. This prevents the liquid-phase working fluid F(L) and gas-phase working fluid F(g) from leaking from the container 2, and also adjusts the pressure in the internal space S to operate at a desired operating temperature. It is composed of

The planar shape of the container 2 is not particularly limited, and may be a rectangular shape as shown in FIG. 1, as well as various shapes such as a circle, a triangle, and a polygon. It is preferable to have a corresponding shape. The thickness of the container 2 is not particularly limited, but is preferably in the range of, for example, 0.1 mm or more and 2.0 mm or less.

The material constituting the container 2 is not particularly limited, and examples thereof include thermally conductive materials. In particular, from the viewpoint of obtaining high thermal conductivity, the container 2 is preferably made of a metal or an alloy, examples of which include copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, iron alloy (e.g., stainless steel), titanium, and titanium alloy. Among these, from the viewpoint of obtaining particularly high thermal conductivity, the container 2 is preferably made of copper or a copper alloy.

The working fluid F sealed in the container 2 is not particularly limited, and a wide variety of materials can be used, such as an electrically insulating refrigerant. Specific examples include water, fluorocarbons, cyclopentane, ethylene glycol, and mixtures thereof. Among these working fluids F, from the viewpoint of electrical insulation, fluorocarbons, cyclopentane, and ethylene glycol are preferred, and fluorocarbons are particularly preferred.

The vessel 2 is provided with an evaporation section 3 that evaporates the working fluid F, a condensation section 4 that is disposed at a position separated from the evaporation section 3 and that condenses the working fluid F, and an intermediate section 5 that is disposed between the evaporation section 3 and the condensation section 4. More specifically, the vessel 2 is provided with an evaporation section 3 that evaporates the liquid-phase working fluid F(L) and changes its phase to a gas-phase working fluid F(g), a condensation section 4 that is disposed at a position separated from the evaporation section 3 and that condenses the gas-phase working fluid F(g) and changes its phase to a liquid-phase working fluid F(L), and an intermediate section 5 that is disposed between the evaporation section 3 and the condensation section 4.

Of these, the evaporator 3 is formed in the container 2 at a position corresponding to the mounting position P of the heating element 7, and for example, in the heat transport device 1 of FIG. 1A, it is formed at one end side portion of the container 2. The evaporator 3 has a function of receiving heat (absorbing heat) from the heat generating element 7 to which it is thermally connected. Specifically, as shown in FIG. 2, the heat from the heating element 7 is transferred to the liquid-phase working fluid F(L) sealed in the internal space S of the container 2. By heating and evaporating F(L) to cause a phase change to a gaseous working fluid F(g), the heat received from the heating element 7 as latent heat of vaporization is absorbed.

Further, the condensing section 4 is arranged at a position separated from the evaporating section 3, and for example, in the heat transport device 1 of FIG. 1A, it is arranged at the other end side of the container 2. The condensing section 4 has a function of radiating heat from the gas phase working fluid F(g) that has undergone a phase change in the evaporating section 3 and is transported. Specifically, as shown in FIG. 2, the condensing section 4 condenses the gas phase working fluid F(g) to change the phase to the liquid phase working fluid F(L), thereby reducing the latent heat of condensation. The heat of the working fluid F(g) transported as a liquid is released to the outside of the container 2. On the other hand, the liquid-phase working fluid F(L) generated in the condensing section 4 flows along grooves 6, which will be described later, and returns to the evaporating section 3 via the intermediate section 5. The liquid-phase working fluid F(L) returned to the evaporator 3 is used again to absorb heat from the heating element 7.

Further, the intermediate section 5 is disposed between the evaporation section 3 and the condensation section 4, and allows gas-phase working fluid F(g) to flow from the evaporation section 3 to the condensation section 4 and from the condensation section 4 to the evaporation section. The working fluid F(L) in the liquid phase flowing toward the pump 3 is configured to form fluid flows in opposite directions. In the intermediate section 5, the liquid-phase working fluid F(L) is supplied to the evaporation section 3 along the groove 6, and the gas-phase working fluid F(g) is condensed through the gap above the groove 6. 4.

(groove)
The heat transport device 1 of the present invention includes at least one groove 6 on the inner circumferential surface 2a of the container 2, which continuously extends from the condensing section 4 to the evaporating section 3 via the intermediate section 5. Here, the groove 6 is provided in at least the heat transfer member 21 of the two metal sheets described above.

The groove 6 is configured such that a liquid working fluid F(L) flows therein. As a result, a flow of the liquid working fluid F(L) along the groove 6 is formed from the condensing part 4 to the evaporating part 3 via the intermediate part 5. (L) can be quickly supplied to the evaporation section 3.

The shape of the groove 6 is such that, when viewed from the cross section of the container 2, the opening groove width w ₁ of the groove located in the intermediate part 5 is the same as the opening groove width w 2 of the groove located in the evaporating part 3 and the opening groove width w ₂ of the groove located in the condensing part 4. The opening groove width _w3 of the groove is configured to be narrower than the opening width w3 of the groove. More specifically, the opening groove width w ₁ of the groove portion located in the middle part 5 when viewed in a cross section of the container 2 across the middle part 5 as shown in FIG. 1B is shown in FIG. 1C. The opening groove width w2 of the groove portion located in the evaporation section 3 when viewed in a cross section of the container 2 that crosses the evaporation section 3, and the width _w2 of the opening groove of the groove portion located in the evaporation section 3 when viewed in a cross section of the container 2 that crosses the condensation section 4 shown in Fig. 1D. It is preferable that the opening groove width w3 of the groove portion located in the condensing section 4 is narrower than that of the opening groove width _w3 . As a result, in the intermediate portion 5, the contact area between the gas-phase working fluid F(g) and the liquid-phase working fluid F(L) becomes small. Therefore, the phase change to the liquid phase that occurs when the gas phase working fluid F (g) is cooled by the liquid phase working fluid F (L) in these contacting parts is reduced, and the gas phase changes. It is possible to suppress a decrease in heat transport performance due to a phase change of the working fluid F(g). In addition, in the intermediate portion 5, a capillary force larger than that in the condensing portion 4 acts on the liquid phase working fluid F(L), so that the liquid phase working fluid F(L) is drawn from the condensing portion 4 to the intermediate portion 5. Therefore, the reflux of the working fluid F can be promoted.

Here, the size of the opening groove width _w1 of the groove portion located in the intermediate portion 5 of the groove 6 can be the opening groove width measured at the opening positions 6a, 6a'. The size of this opening groove width _w1 is preferably in the range of 0 μm to 300 μm, and more preferably in the range of 0 μm to 100 μm.

Moreover, it is preferable that the width of the groove portion of the groove 6 located in the intermediate portion 5 is configured to increase from the opening positions 6a, 6a' toward the groove depth direction (Z direction in FIG. 1B). This allows more liquid-phase working fluid F(L) to flow through the groove 6 while narrowing the opening groove width _w1 of the groove portion, so that the gas-phase working fluid in the intermediate portion 5 The phase change of F(g) to a liquid phase can be made more difficult to occur.

Note that the width of the groove portion of the groove 6 located in the evaporation section 3 and the condensation section 4 is determined by the width of the groove portion located in the evaporation section 3 and the condensation section 4. (L) is preferably equal throughout the groove depth direction (Z direction in FIG. 1B) in order to facilitate recovery into the groove 6.

On the other hand, the opening groove width _w2 of the groove portion of the groove 6 located in the evaporation section 3 can be the opening groove width when measured at the opening positions 6b and 6b', and the opening groove width w2 of the groove portion located in the condensation section 4 The opening groove width _w3 of the groove portion can be the opening groove width when measured at the opening positions 6c and 6c'. The widths of these opening grooves w ₂ and w ₃ are preferably in the range of 50 μm or more and 500 μm or less, and more preferably in the range of 100 μm or more and 400 μm or less.

The depth d of the groove 6 refers to the distance from the portion of the inner peripheral surface 2a where the groove 6 is not formed to the bottom of the groove, whether the groove 6 is open or not. From the viewpoint of reducing the pressure loss of the working fluid F and making it easier for the working fluid F to flow through the groove 6, the groove 6 in the groove portion that continuously extends from the condensing part 4 through the intermediate part 5 to the evaporating part 3 The depth d is preferably 100 μm or more, more preferably 150 μm or more, in each of the groove portions located in the evaporation section 3, intermediate section 5, and condensation section 4. On the other hand, the upper limit of the depth d of the groove 6 is 2000 μm or less in each of the groove portions located in the evaporation section 3, the intermediate section 5, and the condensation section 4, from the viewpoint of not increasing the space of the heat transport device 1 more than necessary. It is preferable that it is, and it is more preferable that it is 1000 micrometers or less. In particular, when the heat transport device 1 is a thin device such as a vapor chamber as in this embodiment, the upper limit of the depth d of the groove 6 is located at the evaporation section 3, the intermediate section 5, and the condensation section 4. Each of the groove portions may be 400 μm or less.

In particular, the groove portion of the groove 6 located in the intermediate portion 5 has a groove depth d 1 with respect to the opening groove width w ₁ when viewed in a cross section of the container 2 that crosses the intermediate portion 5 as shown in FIG. _1B . The ratio is preferably in the range of 0.5 or more and 50 or less, and more preferably in the range of 1 or more and 20 or less. By setting the ratio of the groove depth _d1 to the opening groove width _w1 within this range, the pressure loss of the working fluid F is reduced, so that the working fluid flows from the condensing section 4 to the evaporating section 3 via the groove 6. The distribution of F can be made smoother. Further, the groove 6 in which the ratio of the groove depth d _{1 to the opening groove width w 1 is} within the range of 0.5 or more and 10 or less is formed by laser processing to form the groove 6 and then press forming to form the intermediate part. It can be easily formed by narrowing the opening groove width _w1 of the groove portion located at 5.

In order to efficiently return more liquid working fluid F(L) to the evaporator 3, the groove 6 is preferably configured with a plurality of grooves. In this embodiment, as shown in FIG. 1A, a plurality of grooves 6 are arranged parallel to each other on the inner circumferential surface 2a of the container 2 at intervals. As a result, the liquid working fluid F(L) flows through each of the grooves 6 arranged in parallel, so that the liquid working fluid F(L) flows in a wider range along the width direction of the heat transport device 1 (Y direction in FIG. 1A). Since the working fluid F(L) can be circulated, uneven distribution of the liquid working fluid F(L) in the evaporator 3 can be reduced and dryout can be made difficult to occur.

Among the grooves 6 arranged on the inner circumferential surface 2a of the container 2, the spacing v along the width direction (Y direction in FIG. 1A) in the groove portions located in the evaporation section 3 or the condensation section 4 is preferably in the range of 200 μm to 1000 μm. In particular, by setting the spacing v of the grooves 6 in the range of 400 μm to 1000 μm, a shape in which the opening groove width of the groove portion located in the intermediate section 5 is narrow can be easily formed by press molding.

Furthermore, it is preferable that the groove 6 has a porous layer 8 formed on the inner surface of at least the groove portion located in the evaporation section 3. This increases the surface area of the inner surface of the groove portion located in the evaporation section 3, making it easier for the working fluid F1 in the evaporation section 3 to change phase from liquid to gaseous. In addition, the capillary force of the porous layer 8 draws the liquid working fluid F (L) from the condensation section 4 and the intermediate section 5 to the porous layer 8, promoting the reflux of the working fluid F.

The method for manufacturing the heat transport device 1 having such grooves 6 is not particularly limited, and for example, at least the portion of the container 2 that will become the inner circumferential surface 2a of the heat transfer member 21 may be processed by laser processing, Cutting, extrusion, etching, etc. can be used. Among them, from the viewpoint of forming the groove 6 with fewer man-hours, the inner circumferential surface 2a of the container 2 is laser-processed to form the original shape of the groove 6, and then press molding is performed to form the groove located in the intermediate portion 5. It is preferable to include a step of forming the groove 6 by narrowing the opening groove width _w1 . Furthermore, when forming the groove 6 by laser machining, at least the inner surface of the groove portion located in the evaporation part 3 is generated by laser machining to generate fine powder inside the groove and locally heated. It is also possible to form the porous layer 8 on the inner surface of the groove portion where it is located.

After forming the groove 6 in at least the heat transfer member 21 of the container 2, the end T1 of the heat transfer member ₂₁ and the end T1 of the lid body 22 are removed, leaving a portion of the end T of the container 2 that will become the sealing opening. ₂ are brought into contact and sealed, and the working fluid F is injected from the sealing port. After the working fluid F is injected, the inside of the container 2 is subjected to a degassing process such as heating degassing or vacuum degassing to bring it into a reduced pressure state. Thereafter, the heat transport device 1 is manufactured by sealing the sealing port.

The sealing method is not particularly limited, and examples include TIG welding, resistance welding, pressure welding, and soldering. The first sealing (sealing other than the part that will become the sealing port) is a process performed to seal other than the part from which the internal gas escapes during the subsequent degassing, and the second sealing (sealing the sealing port) is a process performed to seal the part from which the internal gas escapes during degassing.

(Operating principle of vapor chamber)
In the vapor chamber that is the heat transport device 1, a liquid-phase working fluid F(L) is sealed in the internal space S before operation and is supplied to the evaporation section 3.

When the heating element 7 generates heat and the temperature of the evaporator 3 rises, the heat from the heating element 7 is transferred to the container 2, and then to the evaporator 3 located in the container 2 near the heating element 7. In the evaporator 3, the liquid-phase working fluid F(L) is heated and its temperature rises until it reaches the boiling temperature, causing a phase change from the liquid-phase working fluid F(L) to the gas-phase working fluid F(g), which is then released into the internal space S. In addition, the phase change from the liquid-phase working fluid F(L) to the gas-phase working fluid F(g) causes the heat from the heating element to be absorbed by the gas-phase working fluid F(g) as latent heat of vaporization.

The gas phase working fluid F(g) that absorbs heat in the evaporation section 3 flows through the internal space S of the container 2 to the condensation section 4, and the heat received from the heating element 7 is transported from the evaporation section 3 to the condensation section 4 via the intermediate section 5. At this time, the gas phase working fluid F(g) transported from the evaporation section 3 to the condensation section 4 has a reduced contact area with the liquid phase working fluid F(L) flowing through the intermediate section 5 due to the narrow opening of the groove 6 in the intermediate section 5, making it difficult for the gas phase working fluid F(g) to condense in the intermediate section 5, and allowing heat to be transported to the condensation section 4 more reliably.

Thereafter, the gas phase working fluid F(g) transported to the condensing section 4 is changed into a liquid phase by a heat exchange means (not shown) in the condensing section 4. At this time, the heat of the heating element transported is released to the outside of the vapor chamber as latent heat of condensation. On the other hand, the liquid-phase working fluid F(L), which has released heat and changed into a liquid phase in the condensing section 4, flows along the groove 6 from the condensing section 4 through the intermediate section 5 to the evaporating section 3. Thus, a circulating flow of the working fluid F between the evaporating section 3 and the condensing section 4 can be formed.

<Second embodiment>
FIG. 3 is a diagram showing the internal structure of a modified example of the vapor chamber that is the heat transport device of the first embodiment, in which FIG. 3(a) is a plan view, and FIG. 3(b) is a plan view of FIG. 3(a). FIG. 2 is a cross-sectional view taken along line II _A - II _A of FIG. In the following description, the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted or simplified, and differences will be mainly described.

In the first embodiment described above, as shown in FIG. 1B, when viewed from the cross section of the container 2, the opening groove width _w1 of the groove portion located in the intermediate portion 5 is narrower than the opening groove width of the other groove portions. Although the configuration is shown, for example, as in the heat transport device 1A shown in FIGS. 3A and 3B, the opening of the groove portion located in the intermediate portion 5 of the groove 6A may be closed. In particular, when the opening of the groove portion located in the intermediate portion 5 is closed, the opening groove width w ₁ of the groove portion located in the intermediate portion 5 is zero.

In the heat transport device of the present invention, it is particularly preferable that the openings of the groove portions located in the intermediate portion 5 are closed. As a result, in the intermediate portion 5, the gas phase working fluid F(g) and the liquid phase working fluid F(L) become more difficult to come into contact with each other, so that the liquid phase of the gas phase working fluid F(g) is activated. By making it difficult to cause a phase change to a liquid phase due to contact with the fluid F(L), it is possible to further suppress a decrease in the heat transport performance of the heat transport device 1A.

<Third embodiment>
FIG. 4 is a diagram showing the internal structure of a heat pipe, which is a heat transport device according to a third embodiment, in which FIG. 4(a) is a vertical cross-sectional view, and FIG. _A -III _A cross-sectional view when cut on line A, FIG. 4(c) is a cross-sectional view when cut on III _B -III _B line in FIG. 4(a), and FIG. 4(d) is FIG. 4(a) FIG. 2 is a cross-sectional view taken along line _IIIC - _IIIC of FIG. In addition, in FIG. 4(a), in order to make it easier to understand the portion occupied by the groove 6 in the inner circumferential surface 2a of the container 2B, the inside of the groove 6 is shown in black. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted or simplified, and differences will be mainly described.

As shown in FIG. 4(a), the heat transport device 1B according to the third embodiment includes a tubular container 2B having an internal space S in which a working fluid F is sealed. It includes an evaporation section 3, an intermediate section 5, and a condensation section 4 along the . The heat transport device 1B also includes at least one groove 6 on the inner circumferential surface 2a of the container 2, which extends continuously from the condensing section 4 through the intermediate section 5 to the evaporating section 3.

(container)
In the heat transport device 1B of this embodiment, the container 2B has an internal space S formed by a tubular container sealed at ends T ₃ and T ₄ , and is used as a heat pipe. Here, the internal space S of the container 2B in which the heat transport device 1B is provided is a space sealed from the external environment, and the pressure is reduced by a degassing process. The heat pipe, which is the heat transport device 1 of this embodiment, operates on the same principle of operation as the vapor chamber, but the container 2B is a tubular container and has a relatively large internal space S. , different from the vapor chamber container.

The extending shape of the container 2B in the longitudinal direction L is not particularly limited, and includes a straight shape shown in FIG. 4(a), a shape having a curved part, and the like. The outer contour shape of the container 2B when cut in a direction orthogonal to the longitudinal direction L is not particularly limited, and may include a substantially circular shape shown in FIG. 4(c), a flat shape, a polygonal shape such as a quadrangular shape, etc. . The outer diameter of the container 2B is not particularly limited, but for example, when the container 2B has a substantially circular outer contour, it is preferably in the range of 5 mm or more and 20 mm or less.

The container 2B includes an evaporation section 3 that evaporates the liquid-phase working fluid F(L) to change its phase to the gas-phase working fluid F(g), and is disposed at a position separated from the evaporation section 3 to change the phase of the liquid-phase working fluid F(L) to the gas-phase working fluid F(g). A condensing section 4 that condenses the working fluid F(g) to change its phase to a liquid-phase working fluid F(L), and an intermediate section 5 disposed between the evaporating section 3 and the condensing section 4 are provided.

(groove)
The heat transport device 1B of this embodiment has grooves 6 on the inner circumferential surface 2a of the container 2B, which continuously extend from the condenser section 4 through the intermediate section 5 to the evaporator section 3. The heat transport device 1B is configured so that a liquid working fluid F (L) flows through at least one of the grooves 6.

The shape of the groove 6 is such that, when viewed in a cross section of the container 2B, the opening groove width _w1 of the groove portion located in the intermediate portion 5 is narrower than the opening groove width of other groove portions, or the opening groove width w1 is located in the intermediate portion 5. The opening of the groove portion is configured to close. More specifically, the opening groove width w ₁ of the groove portion located in the intermediate portion 5 when viewed in a cross section of the container 2B that crosses the intermediate portion 5 as shown in FIG. 4(b) is The opening groove width w ₂ of the groove portion located in the evaporation section 3 when viewed in the cross section of the container 2B that crosses the evaporation section 3 shown in (c), and the condensation section 4 shown in FIG. 4(d). It is preferable that the width is narrower than the opening groove width _w3 of the groove portion located in the condensing part 4 when viewed in a cross section of the container 2B that it traverses. More preferably, the opening of the groove portion located in the intermediate portion 5 is configured to be closed. As a result, in the intermediate portion 5, the contact area between the gas-phase working fluid F(g) and the liquid-phase working fluid F(L) becomes small. Therefore, the phase change to the liquid phase that occurs when the gas phase working fluid F (g) is cooled by the liquid phase working fluid F (L) in these contacting parts is reduced, and the gas phase changes. It is possible to suppress a decrease in heat transport performance due to a phase change of the working fluid F(g).

A plurality of grooves 6 may be provided as shown in FIG. 4 . At this time, it is sufficient that the liquid working fluid F(L) flows through at least one of the grooves 6, and there may be a groove in which the liquid working fluid F(L) does not flow.

The method for manufacturing the heat transport device 1B having such grooves 6 is not particularly limited. For example, the inner circumferential surface 2a of the container 2B may be subjected to laser processing, cutting, extrusion molding, etching, etc. Can be used. Among them, from the viewpoint of forming the grooves 6 with fewer man-hours, one surface of the flat plate that is the material of the container 2 is laser-processed to form the original shape of the grooves 6, and then press molding is performed to form the intermediate part 5. It is preferable to have a step of forming the groove 6 by narrowing the opening groove width _w1 of the groove portion located at. After forming the groove 6 in the flat plate, the flat plate is rolled up to form a tubular container 2B, and the tubular container 2B is sealed leaving a portion (end T3 or T4) that will become the sealing port, and the operation is performed from the filling port. Inject fluid F. After injecting the working fluid F, the inside of the container 2B is subjected to a degassing process such as heating degassing or vacuum degassing to bring it into a reduced pressure state. Thereafter, the heat transport device 1B is manufactured by sealing the sealing port.

(The working principle of heat pipes)
Next, the mechanism of heat transport in a heat pipe, which is the heat transport device 1, will be described below using the heat pipe shown in FIG.

First, the liquid phase working fluid F (L) is supplied to the evaporation section 3 along the groove 6 extending in the longitudinal direction on the inner circumferential surface 2a of the container 2.

When the heating element 7 generates heat and the temperature of the evaporator 3 rises, the heat of the heating element 7 is transferred to the container 2B, and the heat is transferred to the evaporator 3 in the vicinity of the heating element 7 in the container 2B. In the evaporation section 3, the liquid-phase working fluid F(L) is heated and its temperature rises to reach boiling temperature, and the liquid-phase working fluid F(L) is converted into the gas-phase working fluid F(g). Due to this change, the gas phase working fluid F(g) is discharged into the internal space S. Furthermore, due to the phase change from the liquid-phase working fluid F(L) to the gas-phase working fluid F(g), heat from the heating element is absorbed into the gas-phase working fluid F(g) as latent heat of vaporization.

The gas phase working fluid F(g) that has absorbed heat in the evaporator 3 flows through the internal space S of the container 2B to the condensing part 4, so that the heat received from the heating element 7 is transferred from the evaporator 3 to the intermediate It is transported to the condensing section 4 via the section 5. At this time, the gas-phase working fluid F(g) transported from the evaporating section 3 to the condensing section 4 is controlled by the liquid-phase working fluid flowing through the intermediate section 5 due to the narrow opening of the groove 6 in the intermediate section 5. Since the contact area with the fluid F(L) is reduced, condensation of the gas phase working fluid F(g) in the intermediate section 5 is made difficult to occur, and heat can be more reliably carried to the condensing section 4. .

The gas phase working fluid F(g) transported to the condenser 4 is then changed to liquid phase in the condenser 4. At this time, the heat of the transported heating element is released to the outside of the heat pipe as latent heat of condensation. On the other hand, the liquid phase working fluid F(L) that has released heat and changed to liquid phase in the condenser 4 flows along at least one groove 6 from the condenser 4 through the intermediate section 5 to the evaporator 3, thereby forming a circulating flow of working fluid F between the evaporator 3 and the condenser 4.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and includes all aspects included in the concept of the present invention and the scope of the claims. It can be modified to .

1, 1A, 1B Heat transport device 2, 2B Container 2a Inner peripheral surface of container 21 Heat transfer member 22 Lid 3 Evaporation section 4 Condensation section 5 Intermediate section 6, 6A Groove 7 Heating element 8 Porous layer F Working fluid F( L) Working fluid in liquid phase F(g) Working fluid in gas phase S Internal space T End of container T ₁ End of heat transfer member T ₂ End of lid T ₃ , T ₄ End of tubular container

Claims (10)

It has a working fluid inside the container,
an evaporation section that evaporates the working fluid;
a condensing section that is arranged at a position separated from the evaporating section and condenses the working fluid;
A heat transport device comprising an intermediate section disposed between the evaporation section and the condensation section,
The container includes at least one groove on an inner circumferential surface that continuously extends from the condensing section to the evaporating section via the intermediate section,
The groove is
The opening groove width of the groove located in the intermediate part is narrower than the opening groove width of the groove located in the evaporating part or the condensing part, or the opening part of the groove located in the intermediate part is closed ,
The condensation section, the intermediate section and the bottom of the evaporation section have equal widths, and
The width of the groove portions located in the evaporation section and the condensation section is equal throughout the groove depth direction . The heat transport device according to claim 1, wherein the opening groove width when measured at the opening position of the groove portion located in the intermediate portion is in a range of 0 μm or more and 300 μm or less. The heat transport device according to claim 1 or 2, wherein the width of the groove portion located in the intermediate portion is configured to increase from the opening position toward the groove depth direction. The heat exchanger according to any one of claims 1 to 3, wherein the groove depth of the groove portion that continuously extends from the condensation section to the evaporation section via the intermediate section is in the range of 100 μm or more and 2000 μm or less. transportation device. The heat transport device according to any one of claims 1 to 4, wherein the groove portion located in the middle portion has a ratio of groove depth to opening groove width in the range of 0.5 to 50 when viewed in cross section of the container. The heat transport device according to any one of claims 1 to 5, wherein the groove has a porous layer formed on an inner surface of the groove portion located in the evaporation section. The at least one groove is a plurality of grooves, and the plurality of grooves are arranged parallel to each other at intervals on the surface of the container, and the intervals are in the range of 200 μm or more and 1000 μm or less. 7. A heat transport device according to any one of claims 1 to 6. The heat transport device according to any one of claims 1 to 7, wherein the container is made of copper, a copper alloy, aluminum, an aluminum alloy, nickel, a nickel alloy, an iron alloy, titanium, or a titanium alloy. The container has an interior space defined by two metal sheets sealed at the ends;
The heat transport device according to any one of claims 1 to 8, which is used as a vapor chamber. The inner space of the container is constituted by a tubular container that is sealed at the end,
Heat transport device according to any one of claims 1 to 8, used as a heat pipe.

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