JP7433982B2 - Heat transport equipment and heat exchange units - Google Patents

Description

The present invention relates to a heat transport device and a heat exchange unit.

In recent years, power converters (inverters) and lithium-ion batteries installed in various vehicles such as next-generation vehicles such as hybrid vehicles and electric vehicles and high-speed railway vehicles are being enclosed in airtight containers in order to dissipate and equalize heat. A heat transport device is used that cools a heating element by utilizing latent heat generated when a working fluid undergoes a phase change, and transports the heat to a position separated from the heating element.

Here, the heat transport device includes a closed vessel (container) having an internal space in which a working fluid is sealed. The closed container includes an evaporation section that evaporates a liquid-phase working fluid to change its phase to a gas-phase working fluid, and a condensation section that condenses the gas-phase working fluid to change its phase to a liquid-phase working fluid. The working fluid whose phase has been changed from a liquid phase to a gas phase in the evaporation section flows from the evaporation section to the condensation section. The working fluid whose phase has been changed from a gas phase to a liquid phase in the condensing section flows from the condensing section to the evaporating section. In this manner, the working fluid circulates between the evaporation section and the condensation section within the closed container, thereby transferring heat between the evaporation section and the condensation section within the closed container. Water, which has a large latent heat (especially heat of vaporization), is generally used as a working fluid in such a heat transport device.

However, when such a heat transport device that uses water as the working fluid is installed in various vehicles used in cold regions, for example, in low-temperature environments with temperatures below -40°C, air is generated in the condensation section of the heat transport device. When the working fluid that has undergone a phase change from a phase to a liquid phase freezes, the heat transport function of the heat transport device tends to deteriorate, and in the worst case, there is a problem that the heat transport device will not start up.

A heat transport device having a heat transport function even in cold regions is described in Patent Document 1, for example. The heat transport device (boiling cooling device) of Patent Document 1 uses a mixed liquid of water and ethanol as a working fluid, and has a configuration in which an internal space is filled with this working fluid. Although ethanol has a smaller heat of vaporization than water, it is larger than other alcohols, so the heat of vaporization as a mixed liquid is relatively large, and the melting point of the working fluid is lower than 0°C, so the patent Document 1 describes a heat transport device that can prevent the working fluid from freezing while preventing burnout (film boiling) by using the above liquid mixture as the working fluid.

International Publication No. 2010/055621

When a working fluid made of a mixture of water and ethanol is used at room temperature (for example, 5 to 40°C), the heat of evaporation is smaller than that of a working fluid made only of water, resulting in poor heat transport performance. There is a problem with being inferior.

The object of the present invention is to provide a heat transport system that can maintain a stable and good heat transport function even under a wide temperature range of use, including for example from a room temperature environment of 5 to 40°C to a low temperature environment. An object of the present invention is to provide a device and a heat exchange unit equipped with the same.

The present inventors have proposed a first refrigerant made of water as a working fluid to be filled in the internal space of a heat transport device, a first refrigerant that is sparingly soluble or insoluble in the first refrigerant, has a melting point lower than that of the first refrigerant, and By using a phase-separated refrigerant as a working fluid in combination with a second refrigerant that has a specific gravity lower than that of the first refrigerant, the refrigerant can be used in a wide temperature range, including both normal temperature and low-temperature environments. The present inventors have discovered that a stable and good heat transport function can be maintained even in the case of heat transfer, and have completed the present invention.

That is, the gist of the present invention is as follows.
(1) An evaporator that evaporates the liquid-phase working fluid to change its phase into a gas-phase working fluid, and an evaporator that evaporates the liquid-phase working fluid to change its phase into a gas-phase working fluid; a condensing section that condenses the gas phase working fluid to change its phase to a liquid phase working fluid, and the working fluid moves between the evaporation section and the condensation section with a phase change. In the heat transport device configured to transport heat, the liquid-phase working fluid filled in the internal space is poorly soluble or insoluble in a first refrigerant consisting of water, and the first refrigerant; and a second refrigerant having a lower melting point than the first refrigerant and a lower specific gravity than the first refrigerant.
(2) The heat transport device according to (1) above, wherein the first refrigerant and the second refrigerant are phase-separated.
(3) The heat transport device according to (1) or (2) above, wherein the second refrigerant is at least one of an alkane, a cycloalkane, and an aromatic hydrocarbon.
(4) The heat transport device according to any one of (1) to (3) above, wherein the second refrigerant is cyclopentane.
(5) The heat transport device according to any one of (1) to (4) above, wherein the second refrigerant has a boiling point of less than 200°C.
(6) The heat transport device according to any one of (1) to (5) above, wherein the second refrigerant has a boiling point higher than 0°C.
(7) The heat transport device according to any one of (1) to (6) above, wherein the second refrigerant has a melting point of -40°C or lower.
(8) The heat transport device according to any one of (1) to (7) above is provided, and the closed container has heating means for heating and evaporating the liquid-phase working fluid in the evaporation section. A heat exchange unit comprising: a cooling means in the condensing section for cooling and condensing the gaseous working fluid.
(9) The heat according to (8) above, wherein the heating means is a base block that is thermally connected, and the cooling means is a plurality of cooling fins provided in parallel in the condensing section of the closed container. replacement unit.

According to the present invention, a heat transporter capable of maintaining a stable and good heat transporting function even under a usage environment in a wide temperature range including from a normal temperature environment of 5 to 40°C to a low temperature environment. A device and a heat exchange unit equipped with the same can be provided.

FIG. 1 is a schematic cross-sectional view of a heat exchange unit equipped with a heat transport device according to the present invention, showing the state of a working fluid filled inside the heat transport device under a normal temperature environment. FIG. 2 is a schematic cross-sectional view of a heat exchange unit equipped with a heat transport device according to the present invention, showing the state of the working fluid filled inside the heat transport device in a low-temperature environment. FIG. 3 is a conceptual diagram for explaining the flow of the working fluid that occurs inside the heat transport device in the normal temperature environment of FIG. FIG. 4 is a conceptual diagram for explaining the flow of working fluid that occurs inside the heat transport device in the low-temperature environment of FIG. 2.

Next, preferred embodiments of the present invention will be described below.

<Embodiment of heat transport device>
FIG. 1 is a schematic cross-sectional view of a heat exchange unit equipped with a heat transport device according to the present invention, showing the state of a working fluid filled inside the heat transport device under a normal temperature environment. Moreover, FIG. 2 is a schematic cross-sectional view of a heat exchange unit equipped with a heat transport device according to the present invention, showing the state of the working fluid filled inside the heat transport device in a low-temperature environment. Furthermore, FIG. 3 is a conceptual diagram for explaining the flow of the working fluid that occurs inside the heat transport device in the normal temperature environment of FIG. Moreover, FIG. 4 is a conceptual diagram for explaining the flow of the working fluid that occurs inside the heat transport device in the low-temperature environment of FIG.

(closed container)
A heat transport device 1 shown in FIGS. 1 to 4 includes a closed container 2 having an internal space S filled with a working fluid F in a liquid phase.

The closed container 2 is not particularly limited as long as it can hold a required amount of liquid-phase working fluid F(L). For example, as shown in FIGS. 1 and 2, the closed container 2 includes a cylindrical accommodating section 2a filled with a liquid-phase working fluid F(L), and a spaced apart position above the accommodating section 2a. It is constituted by cylindrical extension portions 2b and 2c that extend upward, respectively. Moreover, the airtight container 2 may be constituted by a single member such as a container.

The wall thickness of the airtight container 2 is not particularly limited, but is, for example, 0.05 to 1 mm. Further, the extending portions 2b and 2c constituting the airtight container 2 have an outer contour shape when cut in a direction perpendicular to the extending direction, in addition to a substantially circular shape, a flat shape, a polygonal shape such as a quadrangular shape, etc. There may be one, and there is no particular limitation. Furthermore, the outer diameter dimensions of the extended portions 2b and 2c constituting the airtight container 2 are not particularly limited, but may range, for example, from 5 to 20 mm.

The material of the closed container 2 is not particularly limited. In this embodiment, heat is exchanged with the liquid-phase working fluid F(L) held inside the closed container 2 via the evaporation section 3 and the condensation section 4 provided on the outer periphery of the closed container 2. , it is preferable to use metallic materials. Particularly, since it has excellent thermal conductivity, the sealed container 2 can be made of, for example, copper, copper alloy, or the like. Furthermore, from the viewpoint of weight reduction, the sealed container 2 may be made of, for example, aluminum, aluminum alloy, or the like. In addition, the sealed container 2 may be made of, for example, stainless steel because of its high strength. In addition, depending on the usage situation, the sealed container 2 may be made of, for example, tin, tin alloy, titanium, titanium alloy, nickel, nickel alloy, or the like.

(evaporation section and condensation section)
The airtight container 2 includes an evaporation section 3 that evaporates a liquid-phase working fluid F(L) to change its phase into a gas phase, and an evaporation section 3 that condenses a gas-phase working fluid F supplied from the evaporation section 3 to change its phase into a liquid phase. It has a condensing section 4 that changes the temperature. The airtight container 2 of the heat transport device 1 shown in FIGS. 1 to 4 has an evaporation section 3 in a storage section 2a in which a liquid-phase working fluid F(L) is accommodated, and an extended structure above the storage section 2a. The parts 2b and 2c have condensing parts 4, and the whole hermetic container 2 is hermetically sealed.

Of these, the evaporator 3 is formed in the accommodating part 2a of the closed container 2 in FIG. It has the function of changing the phase of the liquid phase working fluid F(L) to the gas phase by absorbing heat (endothermic). More specifically, as shown in FIG. 3, the evaporator 3 uses a liquid-phase first refrigerant F1 (L) and a liquid-phase second refrigerant, which will be described later, as a liquid-phase working fluid F(L). By evaporating F2(L) and causing a phase change to the first refrigerant F1(g) in the gaseous phase and the second refrigerant F2(g) in the gaseous phase, the heat received from the heating element is absorbed as latent heat of evaporation.

Further, the condensing section 4 is preferably disposed above and away from the evaporating section 3, and for example, in FIG. 1, it is preferably disposed at the extending sections 2b and 2c. The condensing section 4 has a function of radiating heat from the gas phase working fluid, which has been transported after changing its phase to a gas phase in the evaporation section 3, using a heat exchange means (not shown). More specifically, as shown in FIG. 3, the condensing section 4 uses a gas phase first refrigerant F1 (g) and a gas phase second refrigerant F2 (g), which are gas phase working fluids. It is condensed and changed into a liquid-phase first refrigerant F1 (L) and a liquid-phase second refrigerant F2 (L), thereby transferring the heat transported by the working fluid as latent heat of condensation to the outside of the heat transport device 1. released into the

In this way, the evaporation section 3 and the condensation section 4 of the heat transport device 1 transport heat between the evaporation section 3 and the condensation section 4 by moving the liquid-phase working fluid F(L) through a phase change. configured to do so.

Note that the method for producing the airtight container 2 is not particularly limited, but one end of the extended portions 2b and 2c is left as a sealing port and sealed, and the liquid phase first refrigerant F1 ( The heat transport device 1 can be manufactured by injecting L) and the liquid phase second refrigerant F2 (L), deaerating the inside of the closed container 2 to create a reduced pressure state, and then sealing the sealing port. can.

(working fluid)
In the heat transport device 1 according to the present embodiment, the liquid-phase working fluid F(L) filled in the internal space S of the closed container 2 includes a first refrigerant made of water, and a first refrigerant that is poorly soluble or insoluble in the first refrigerant. and a second refrigerant that is insoluble, has a lower melting point than the first refrigerant, and has a lower specific gravity than the first refrigerant. When this liquid-phase working fluid F(L) is filled in a liquid state in the storage part 2a of the closed container 2 in the heat transport device 1 before operation, the first refrigerant is on the lower side and the second refrigerant is on the upper side. It exists to become. At this time, it is preferable that the first refrigerant and the second refrigerant are not mixed and exist as independent phases. That is, it is preferable that the first refrigerant and the second refrigerant are phase-separated. Therefore, as shown in FIGS. 2 and 4, for example, the liquid-phase first refrigerant F1 (L) freezes in the condensing section 4 to form the solid-phase first refrigerant F1 (S), thereby forming the liquid-phase first refrigerant F1 (S). Even in a low-temperature environment where the first refrigerant F1(L) does not return to the storage section 2a (for example, an environment of −40° C. or lower), the second refrigerant, which has a lower melting point than the first refrigerant, is As a result of being able to move through a phase change between the heat exchanger and the condensation section 4, it is possible to maintain heat transport performance. As a result, the heat transport device 1 according to the present embodiment can obtain a stable and good heat transport function even when used particularly in a low-temperature environment.

The volume ratio (%) of the liquid phase second refrigerant F2 (L) constituting the liquid phase working fluid F (L) filled in the internal space S of the sealed container 2 is not particularly limited, but is From the viewpoint of enhancing the heat transport function in the liquid phase, the content is preferably less than 5% of the total liquid phase.

Furthermore, under a normal temperature environment where the first refrigerant is in a liquid state, the first refrigerant and the second refrigerant independently repeat evaporation and condensation, as shown in FIGS. 1 and 3, for example. As a result, the heat transport device 1 according to the present embodiment can exhibit a stable and good heat transport function equivalent to the case where only the first refrigerant is used as the working fluid in a normal temperature environment.

(first refrigerant)
Among these, water is used as the first refrigerant. Thereby, when combined with the non-aqueous second refrigerant, phase separation can be facilitated, and chemical reactions with the closed container 2 and the like can be suppressed.

"Phase separation" in the present invention means that the first refrigerant and the second refrigerant are separated into at least two layers in a liquid state. Here, whether or not phase separation has occurred is determined by visual observation. More specifically, the refrigerant in the heat transport device 1 is transferred to a transparent container, and after the color change has completely disappeared, the refrigerant in the container is visually observed. Based on this observation, it is determined whether the refrigerant has undergone phase separation. At this time, it is determined whether the refrigerant is phase-separated or not based on the presence or absence of phases of different colors and the presence or absence of an interface. However, in the case of a refrigerant in which the difference in color is difficult to distinguish and the interface is not clearly visible, it is also possible to analyze the components of the refrigerant at different depths to determine whether or not they are separated. Note that if a phase of the first refrigerant and a phase of the second refrigerant exist, even if there is an intermediate layer between them where the first refrigerant and the second refrigerant are not completely separated, the first refrigerant and the second refrigerant It may be determined that the refrigerant undergoes phase separation.

(Second refrigerant)
The second refrigerant used is one that is poorly soluble or insoluble in the first refrigerant, has a lower melting point than the first refrigerant, and has a lower specific gravity than the first refrigerant. Thereby, the first refrigerant and the second refrigerant can be separated such that the second refrigerant having a lower melting point is on the upper side.

Here, the second refrigerant is a compound having a melting point of less than 0°C. In particular, the melting point of the second refrigerant is preferably -20°C or lower, more preferably -40°C or lower. By using the second refrigerant with a low melting point in this way, even if water, which is the first refrigerant, freezes in a low-temperature environment, the second refrigerant remains in the liquid phase in a temperature range where the second refrigerant does not freeze. It can be operated as a working fluid F(L). Therefore, it is possible to obtain the heat transport device 1 that can be operated even at lower temperatures. In particular, since the melting point of the second refrigerant is -40°C or lower, the heat transport device 1 can operate stably even in a low-temperature environment of -40°C or lower, which was conventionally difficult to use due to freezing. be able to.

Further, the boiling point of the second refrigerant is not particularly limited, and for example, one having a boiling point of less than 200° C. can be used. Among them, from the viewpoint of evaporating the second refrigerant before the water, which is the first refrigerant, and thereby approaching a state in which only the first refrigerant is in the evaporation section 3, the boiling point of the second refrigerant is less than 100 ° C. It is preferable. On the other hand, from the viewpoint of evaporating water, which is the first refrigerant, more preferentially than the second refrigerant, the boiling point of the second refrigerant may be 100° C. or higher. In addition, from the viewpoint of preventing a temperature range in which the heat transport device 1 does not operate, the boiling point of the second refrigerant is preferably higher than 0°C.

The second refrigerant is a compound that is poorly soluble or insoluble in water, which is the first refrigerant. More specifically, the second refrigerant preferably has a solubility in water of 0.1 g/L or less, and more preferably is insoluble in water. Thereby, when combined with water, which is the first refrigerant, it can be separated into two phases.

Further, the specific gravity of the second refrigerant is smaller than the specific gravity of water, which is the first refrigerant. More specifically, the second refrigerant preferably has a specific gravity of less than 1. On the other hand, the specific gravity of the second refrigerant is preferably 0.5 or more. As a result, when the first refrigerant contained in the liquid-phase working fluid F(L) freezes in a low-temperature environment, the frozen first refrigerant is located below the second refrigerant, so that the second refrigerant evaporates. can be carried out more smoothly.

Further, it is preferable that the second refrigerant has a high latent heat of vaporization. More specifically, the second refrigerant preferably has a latent heat of vaporization of 100 [kJ/kg] or more. Thereby, the amount of heat transferred by evaporation and condensation of the second refrigerant can be increased.

The chemical structure of the second refrigerant is not particularly limited, and has no reactivity with the airtight container 2 or the first refrigerant, water, is sparingly soluble or insoluble in water, and has a lower melting point than water; It can be appropriately selected from compounds having a specific gravity smaller than that of water. Among these, from the viewpoint of preventing the second refrigerant from being mixed into the first refrigerant, it is preferable that the second refrigerant contains at least one of an alkane, a cycloalkane, and an aromatic hydrocarbon.

Specific examples of the second refrigerant include cyclopentane (melting point: -94°C, boiling point: 49°C, specific gravity: 0.751, latent heat of vaporization: 389 kJ/kg, insoluble in water); Not limited.

<Embodiment of heat exchange unit>
The heat exchange unit 10 shown in FIGS. 1 to 4 includes the above-described heat transport device 1, and a liquid-phase working fluid F(L) is provided in the evaporation section 3 of the outer peripheral surface of the closed container 2 of the heat transport device 1. It has a heating means that heats and evaporates, and cools and condenses the gas phase working fluid (the gas phase first refrigerant F1 (g) and the gas phase second refrigerant F2 (g)) in the condensing section 4. It has cooling means.

(Heating means)
Among these, the base block 5 thermally connected to a heating element or the like can be used as a heating means for heating and evaporating the liquid-phase working fluid F(L).

The base block 5 is a plate made of a metal material such as aluminum, aluminum alloy, copper, or copper alloy. As shown in FIGS. 1 and 2, the base block 5 is fixed to a lower portion of the heat transport device 1 where the evaporator 3 is located. By providing such a base block 5, the heat in the heating element is quickly transferred to the evaporation section 3 via the base block 5, so that the heating element can be efficiently cooled using the heat exchange unit 10. .

(cooling means)
Further, as a cooling means for cooling and condensing the gas phase working fluid in the condensing section 4, the cooling fins 6 can be mentioned.

The cooling fins 6 are constituted by one or more plates made of a metal material such as aluminum and have a thin flat plate shape, for example, and are provided in plural in parallel in the condensing section 4 . As shown in FIGS. 1 and 2, the cooling fins 6 are fixed to an upper portion of the heat transport device 1 where the condensing section 4 is located. By providing such cooling fins 6, more heat is released from the condensing section 4 to the outside of the heat exchange unit 10 via the cooling fins 6, so that the liquid is removed from the gas phase of the working fluid in the condensing section 4. Phase change to phase can be promoted.

In addition, the heat exchange unit 10 may be provided with a duct member (not shown) that circulates air toward the cooling fins 6.

<Mechanism of heat transport in heat transport devices>
Next, the heat transport mechanism of the heat transport device 1 of the present invention will be explained below using FIGS. 1 to 4.

(Heat transport under normal temperature environment)
In a normal temperature environment before operation, the heat transport device 1 of the present invention uses water, which is a liquid phase first refrigerant F1 (L), as a liquid phase working fluid F (L), and a liquid phase liquid phase first refrigerant F1 (L). A liquid-phase second refrigerant F2 (L) to be separated is held.

Here, when the evaporator 3 of the heat transport device 1 receives heat from a heating means such as a base block 5 that is thermally connected to a heating element, the liquid-phase first refrigerant F1 (L ) and the second refrigerant F2 (L) in the liquid phase to undergo a phase change into a gas phase working fluid (the first refrigerant F1 (g) in the gas phase and the second refrigerant F2 (g) in the gas phase). , absorbs the heat received from the heating element as latent heat of vaporization.

The first refrigerant F1 (g) in the gas phase and the second refrigerant F2 (g) in the gas phase that have absorbed heat in the evaporator 3 pass through the vapor flow path, which is the internal space S of the closed container 2, to the closed container 2. The heat received by the heating means (base block 5) is transported from the evaporation section 3 to the condensation section 4 by flowing from the evaporation section 3 to the condensation section 4.

Thereafter, the first refrigerant F1 (g) in the gas phase and the second refrigerant F2 (g) in the gas phase transported to the condensing section 4 are cooled by cooling means such as cooling fins 6 in the condensing section 4. Phase change to liquid phase. At this time, the heat of the heat generating body that has been transported is released to the outside of the heat transport device 1 as latent heat of condensation. Then, the first refrigerant F1 (L) in the liquid phase and the second refrigerant F2 (L) in the liquid phase, which have released heat in the condensing section 4 and changed into a liquid phase, flow along the inner circumferential surface of the closed container 2. By flowing from the condensing section 4 to the evaporating section 3, the working fluid can be circulated between the evaporating section 3 and the condensing section 4.

(Heat transport in low temperature environment)
Further, in the heat transport device 1 of the present invention, in a low-temperature environment, the second refrigerant F2 (L), which is a liquid phase with a low melting point, maintains a liquid phase state as a liquid phase working fluid F (L). . On the other hand, the liquid-phase first refrigerant F1 (L) freezes when cooled in the condensing section 4 to generate a solid-phase first refrigerant F1 (S), which is stored in the condensing section 4 of the closed container 2. There is a possibility that it will remain attached to the wall. In that case, the solid-phase first refrigerant F1(S) becomes difficult to change to a liquid-phase state and becomes difficult to move to the evaporation section 3, which may lead to a decrease in heat transport performance.

Here, when the evaporator 3 of the heat transport device 1 receives heat from a heating means such as a base block 5 that is thermally connected to a heating element, the liquid-phase second refrigerant F2 (L ) and undergoes a phase change to a gas phase working fluid (gas phase second refrigerant F2(g)), thereby absorbing the heat received from the heating element as latent heat of vaporization.

The second refrigerant F2 (g) in the gas phase, which has absorbed heat in the evaporator 3, flows from the evaporator 3 of the hermetic container 2 to the condensing part 4 through the vapor flow path, which is the internal space S of the hermetic container 2. The heat received by the heating means (base block 5) is transported from the evaporating section 3 to the condensing section 4.

Thereafter, the gas phase second refrigerant F2(g) transported to the condensing section 4 is cooled by cooling means such as the cooling fins 6 in the condensing section 4, and is changed into a liquid phase. At this time, the heat of the heat generating body that has been transported is released to the outside of the heat transport device 1 as latent heat of condensation. Then, the liquid phase second refrigerant F2 (L), which has released heat and changed its phase to the liquid phase in the condensing section 4, is transferred to the inner peripheral surface of the closed container 2 (or inside the solid phase first refrigerant F1 (S)). The working fluid can be circulated between the evaporating section 3 and the condensing section 4 by flowing from the condensing section 4 to the evaporating section 3 along the circumferential surface). At the same time, the first refrigerant can also be caused to flow into the evaporator 3 by melting the solid-phase first refrigerant F1 (S) and changing the phase to the liquid-phase first refrigerant F1 (L).

In this way, the heat transport device 1 of the present invention can provide a stable and good heat transport function both when used in a low temperature environment and when used in a normal temperature environment. In particular, when used in a normal temperature environment, by phase-separating the liquid phase first refrigerant F1 (L) and the liquid phase second refrigerant F2 (L), the liquid phase first refrigerant F1 (L) properties are less likely to be impaired, resulting in better heat transport function.

Furthermore, in a low-temperature environment, even if the first refrigerant F1 freezes in the condensing section 4 and becomes the solid-phase first refrigerant F1 (S), the gas-phase second refrigerant F2 (g) 1 refrigerant F1(S) may be dissolved. At this time, the dissolved first refrigerant F1 undergoes a phase change to a liquid-phase first refrigerant F1 (L), moves to the evaporator 3, and is used for heat transport. That is, in a low-temperature environment, the solid-phase first refrigerant F1 (S) is dissolved by the gas-phase second refrigerant F2 (g), which can also contribute to heat transport.

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 .

The present invention will be explained in more detail below based on Examples, but the present invention is not limited thereto.

(Example of the present invention)
A heat transport device according to an example of the present invention is a heat transport device 1 having a structure shown in FIG. 1, in which a closed container 2 includes a housing portion 2a and extension portions 2b and 2c. Cylindrical extending portions 2b and 2c were provided on the upper surface of the accommodating portion 2a of the closed container 2. Then, one end of the extended portions 2b and 2c is left as a sealing port and sealed, and from this sealing port, 7 g of water, which is the first refrigerant, is supplied as a liquid-phase working fluid F(L). 0.4 g of a second refrigerant, cyclopentane, was injected. Next, the inside of the closed container 2 was deaerated to a reduced pressure state, and then the sealing port was sealed, thereby producing the heat transport device 1. The heat transport device 1 of the example of the present invention operated as a heat transport device even in a low temperature environment of -40°C.

(Comparative example)
In the heat transport device of the comparative example, only water was injected as the liquid phase working fluid F(L) from the sealing port without using a low melting point compound as the liquid phase working fluid F(L). Other than that, the heat transport device was manufactured to have the same configuration as the heat transport device of Example 1 of the present invention. The heat transport device of the comparative example did not operate as a heat transport device in a low temperature environment of -40°C.

1 Heat transport device 2 Closed container (or container)
2a Storage section 2b, 2c Extension section 3 Evaporation section 4 Condensation section 5 Base block 6 Cooling fins 10 Heat exchange unit F(L) Working fluid in liquid phase F1(S) First refrigerant in solid phase F1(L) Liquid phase First refrigerant F1 (g) First refrigerant in gas phase F2 (L) Second refrigerant in liquid phase F2 (g) Second refrigerant in gas phase S Internal space

Claims (9)

A closed container with an internal space filled with liquid-phase working fluid,
an evaporator that evaporates the liquid-phase working fluid to change its phase to a gas-phase working fluid;
a condensing section that condenses the vapor phase working fluid supplied from the evaporation section to change the phase of the gas phase working fluid into a liquid phase working fluid; In a heat transport device configured to transport heat by changing and moving,
The liquid phase working fluid filled in the internal space is
A first refrigerant consisting of water;
a second refrigerant that is hardly soluble or insoluble in the first refrigerant, has a lower melting point than the first refrigerant, and has a lower specific gravity than the first refrigerant;
In the heat transport device , the second refrigerant is at least one of alkanes, cycloalkanes, and aromatic hydrocarbons . The heat transport device according to claim 1, wherein the first refrigerant and the second refrigerant are phase separated. The heat transport device according to claim 1 or 2 , wherein the second refrigerant is cyclopentane. The heat transport device according to any one of claims 1 to 3 , wherein the second refrigerant has a boiling point of less than 200°C. The heat transport device according to any one of claims 1 to 4 , wherein the second refrigerant has a boiling point higher than 0°C. The heat transport device according to any one of claims 1 to 5 , wherein the second refrigerant has a melting point of -40°C or lower. According to any one of claims 1 to 6, the volume fraction (%) of the second refrigerant in the liquid phase constituting the working fluid in the liquid phase is in a range of less than 5% of the total liquid phase. heat transport device. Comprising the heat transport device according to any one of claims 1 to 7,
The airtight container is
The evaporation section includes a heating means for heating and evaporating the liquid phase working fluid,
A heat exchange unit, wherein the condensing section includes a cooling means for cooling and condensing the gaseous working fluid. a base block to which the heating means is thermally connected;
The heat exchange unit according to claim 8, wherein the cooling means is a plurality of cooling fins provided in parallel in the condensing section of the closed container.

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