JP2002115981A - Heat-carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-carrying device for indicating specific heat-carrying performance regardless of the operating posture of a container while improving the heat-carrying capacity with a simple configuration. SOLUTION: In a loop-like closed container that has at least one flow direction regulation means 4 while working fluid 5 reduces its sectional area to the extent that a container section is blocked by the surface tension, a heat- insulating section container wall 2 is inserted between a heating section container wall 1 and a heating section container wall 3, and the heat diffusion from the heating section container wall 1 to the surrounding is inhibited, thus maintaining the heat flux of the heating container and accelerating the generation of bumping of the working fluid and hence the circulation of the working fluid 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer device, and more particularly to a heat transfer device for transferring a large amount of heat generated by electric or electronic equipment to a position distant from a heat source and exchanging heat with a cooling fluid. Heat transfer device.

[0002]

2. Description of the Related Art As a conventional heat transport device, for example, as described in Japanese Patent Publication No. 6-3354, a loop is formed by connecting both terminals of a thin tube in a confidential and communicating manner. The first component is that the inside of the container is circulated while the working fluid is filled and closed by the surface tension due to its surface tension, and the loop type container is provided with a plurality of heat receiving parts and a heat radiating part. In some cases, the second component is defined as having been performed, and the third component is configured such that at least two flow direction regulating means are disposed in the circulation path of the hydraulic fluid.

[0003]

According to such a heat transport device, it is necessary to provide a plurality of heat receiving portions and heat radiating portions. On the other hand, in a general heat transport device, the heat receiving portion and the heat radiating portion are each generally one. In order to apply the present heat transport device in such a case, the thin tube container needs to meander a lot between the heat receiving portion and the heat radiating portion, so that it becomes inevitably complicated, and the heat transport device becomes large. It had to be.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat transport device which has a simple structure and promotes circulation of a working fluid to improve heat transport capability and is less affected by an operating posture. .

[0005]

The object of the present invention is to provide a loop-shaped closed container having a cross-sectional area reduced to such an extent that the liquid phase of a working fluid filled in a gas-liquid two-phase state closes the container cross-section due to surface tension. A container comprising at least one flow direction regulating means in the container, wherein the container comprises a heating portion and a heat radiating portion formed by a container side wall having a large thermal conductivity, and a heat insulating portion is provided between the heating portion and the heat radiating portion. It is achieved by doing.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, a first embodiment of the heat transport device according to the present invention will be described with reference to FIG. FIG. 1 is a configuration diagram of the heat transport device of the present invention. The closed container of the heat transport device in the present embodiment includes a heating unit container wall 1 for absorbing heat generated from the heating element 6 and a radiating unit container wall 3 for radiating the heat absorbed from the heating unit container wall 1 to the outside. And two heat-insulating-portion container walls 2a and 2b inserted between the heating-portion container wall 1 and the heat-dissipating-portion container wall 3 are connected to each other to form a closed loop. Here, the heating unit container wall 1 and the heat radiating unit container wall 3
In order to transfer heat inside and outside the container, a good heat conductive material such as aluminum or copper is used as the material. On the other hand, the heat insulating portion container walls 2a and 2b are provided particularly to prevent heat diffusion from the heating portion container wall 1 in the flow channel axial direction, and have a heat conductivity that is at least one order of magnitude smaller than other container walls. Is used.

[0008] Check valves 4a and 4b for regulating the circulating direction of the working fluid are inserted into the inner space of the loop-shaped container. In FIG. 1, the check valve 4
Both a and 4b are arranged to allow the working fluid to circulate clockwise. The cross-sectional shape of the container is circular. The diameter of the plug is limited to a level at which the liquid phase 5b of the working fluid 5 sealed in the container can form a plug that closes the cross section of the container due to surface tension. This diameter varies depending on the type of working fluid used depending on the surface treatment, but its approximate value can be obtained as follows by solving the governing equation for the interface shape.

Pipe inner diameter <1.94 × (surface tension / (gravity acceleration × (liquid phase density−gas phase density))) The heating section has a circular cross section. In general, the heating element has a rectangular parallelepiped shape. Therefore, in order to improve the attachment of the heating element to the container, the heating block 7 having a rectangular parallelepiped shape is thermally connected to the heating unit container wall 1. The heating element 6 is disposed on the heating block 7 so as to be thermally connected thereto.

The heat radiating section is generally arranged so as to have a large surface area with respect to the heating section. Furthermore, in this embodiment, in order to improve the heat radiation capability, a heat radiation block 8 through which, for example, cooling water or the like is passed is provided so as to be thermally connected to the heat radiation part container wall 3. Therefore, in the present embodiment, the heating element 6
Is radiated through the heat radiating part container wall 3 and the heat radiating block 8 to the ambient air or the cooling fluid flowing through the heat radiating block 8.

Next, the operation of the heat transport device will be described. The heat transport from the heat absorbing source to the heat radiating source of the present heat transport device realizes the heat transport by continuously performing the following four state changes.

When the heat is applied to the heating container wall 1, the pressure and the temperature of the liquid phase 5b of the working fluid located on the heating unit container wall increase while keeping the same volume. Here, in a normal closed two-phase thermosiphon, evaporation from the liquid phase is promoted by the applied heat, and the pressure and temperature inside the container are uniformly increased. However, at the gas-liquid interface in the case of the present heat transport device, evaporation is suppressed because the surface tension is dominant, and the liquid phase is kept substantially constant in volume, and further with respect to the saturation temperature defined from the vapor pressure curve. High temperature (superheat)
And a metastable state exists.

When the degree of superheat increases in the liquid phase 5b indicated by the isothermal isothermal change, the probability that high-energy molecules sufficient to cause evaporation inside the liquid phase increase at one location, and a sufficiently large number of active molecules collect When the lump is formed, bubbles 5a are generated in the liquid. Generated air bubbles 5
a grows rapidly in the heating section container. Hereinafter, this evaporation phenomenon is referred to as “bumping”. Since the check valve 4a prevents the growth in the counterclockwise direction, as a result, the bubble 5a grows in the clockwise direction.

Since the growth rate of the bubbles 5a generated by the adiabatic expansion change is high, the bubbles 5a tend to expand further by inertia even after the growth as a result of the phase change ends. The liquid phase 5b of the working fluid filled in the container by the expansion work at this time moves clockwise, and part of the liquid phase 5b passes through the check valve 4a and is refilled to the wall of the heating unit block.

The bubbles 5a which have been adiabatically expanded during the isothermal isothermal change are condensed by being cooled in the radiator. The volume of the bubble 5a is reduced by the condensation. At this time, there is a possibility that a circulating force in the counterclockwise direction may be generated in the radiator block,
The check valve 4b prevents this.

With the above-described state change as one cycle, a heat transport mechanism is formed in which heat applied to the heating unit container wall 1 flows out of the heat radiating unit container wall 3. Note that, in the above operation, since there is no portion that utilizes gravity, in this configuration, the heating unit is disposed above the heat radiation unit. This is a configuration that enables heat transport in a so-called top heat mode.

What is particularly important practically in the above operation is that bumping in the heating unit container wall 1 is stably generated. For that purpose, it is necessary to always control the heat flux (heat density) on the inner surface of the heating unit container wall to a threshold value or more at which bumping easily occurs. In this embodiment, in order to realize this, the heat insulating part container wall 2 is inserted between the heating part container wall 1 and the heat radiating part container wall 3. That is, when there is no heat insulating part container wall, the heat generated from the heating element diffuses by heat conduction to the heat radiating part container wall via the heating part container wall. Because of this,
The heat flux transmitted from the inner surface of the heating unit container to the working fluid becomes small, so that the period of bumping becomes longer, the occurrence of bumping becomes unstable, and in some cases, bumping stops.

On the other hand, in the present embodiment, since the heat leaking from the heating unit container wall to the surroundings is suppressed, the heat flux can be maintained at a stable value. As a result, bumping can be stably generated in a short cycle. The temperature difference between the heating part container wall and the heat insulation part container wall is larger than that without the heat insulation part container wall. It is negligible compared to the effect. As described above, the configuration of the present embodiment makes it possible to improve the heat transport capability of the entire heat transport device.

Next, a second embodiment of the heat transport device according to the present invention will be described with reference to FIG. This apparatus is different from the first embodiment in that the heat flux is increased near the inner surface of the heating unit container wall 1 in order to generate more stable and low-period bumping. Specifically, the heating unit container wall 1
The heat flux was locally increased by providing a plurality of heat insulating portions 9 on the inner surface of the. In this case, since the heat insulating portion 9 is discretely arranged on the inner surface, the temperature rise inside the heat radiating portion container wall due to the contraction of the heat flow is compared with the case where the heat insulating portion is arranged at one place in the same area. It can be kept smaller.

Next, a third embodiment of the heat transport device according to the present invention will be described with reference to FIG. This apparatus locally increased the heat flux by covering the inner surface of the heating unit container wall 1 using a part of the heat insulating unit container wall 2 in the first embodiment. As a result, it is possible to further improve the heat transport ability by generating bumps having a more stable and low cycle than in the first embodiment, and at the same time, to achieve a heat flow with a simpler configuration compared to the second embodiment. Bundle control is possible.

Next, a fourth embodiment of the heat transport device according to the present invention will be described with reference to FIG. In this device, the container diameter of the heat insulating part container wall 2a on the side where the working fluid flows in from the heating part container wall 1 is smaller than the diameter of the heating part container wall 1 as compared with the third embodiment. With this configuration, the generated bubbles are prevented from growing counterclockwise during bumping, so that the check valve 4a in the first embodiment can be omitted, and the device is more simplified.

[0022]

According to the heat transport device of the present invention, the power that can be extracted from the cycle operation of the working fluid is used, and the heat flux of the heating container portion having a thermal conductivity is controlled to stabilize bumping. Because of this, the heat transport capacity of the entire apparatus is significantly improved. In addition, since the operation of the heat transport device is hardly affected by gravity, the degree of freedom in designing equipment is greatly improved. Further, the present apparatus does not require external power and has no movable parts other than the flow direction regulating means, so that high reliability can be ensured and it can be supplied at low cost.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a heat transport device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a heating unit of a heat transport device and peripheral components thereof according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a heating unit of a heat transport device and its peripheral parts according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a heating unit of a heat transport device and its peripheral parts according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heating container wall, 2 ... Heat insulation container wall, 3 ... Heat dissipation container wall, 4 ... Check valve, 5a ... Working fluid (gas phase), 5b ... Working fluid (liquid phase), 6 ... Heating element, 7 ... Heating Block: 8: heat dissipation block, 9: heat insulation wall, 10: container.

Claims (3)

[Claims] 1. A closed container in the form of a loop having a cross-sectional area reduced to such an extent that a liquid phase of a working fluid filled in a gas-liquid two-phase state closes a cross section of the container by surface tension, and one or more flows in the container. In the heat transport device provided with a direction regulating means, the container is configured such that a heating section and a heat radiating section are formed by a container side wall having a large thermal conductivity, and a heat insulating section is provided between the heating section and the heat radiating section. And heat transport equipment. 2. The heat transport device according to claim 1, wherein the heat insulating portion is provided on a part of the inner surface of the heating portion container with which the working fluid contacts. 3. The heat insulation part is received two with the heating part interposed therebetween, and the flow path cross-sectional area of one heat insulation container wall is smaller than the wetting length of the other container walls. Item 2. The heat transport device according to Item 1.