JPH04260791A - Heat transporting device - Google Patents

Abstract

PURPOSE:To reduce thickness and weight of a metal block type heat transporting device, to increase the area of the device, and to eliminate a variation in performance according to a holding attitude by altering a structure of a heat pipe formed in a metal block to a type for transporting the quantity of heat by axial vibration of and smooth circulation of operating liquid. CONSTITUTION:A sealed container in which a cavity vessel is formed in a metal block, a heat pipe containing two-phase operating liquid to be sealed therein, is formed therein, and the vessel is formed of pore group 2 provided with many pores of parallel rows and a plurality of header cavities 3 for fixedly coupling them at both ends of the group 2 in such a manner that the inner diameter of each pore is so sufficiently reduced as to block the pore by the surface tension of the operating fluid and to allow the fluid to always flow in the blocked state.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to the structure of a heat transport device using a heat pipe, and in particular to a heat pipe that transports heat by axial vibration and gentle circulation of a working fluid in a container. Concerning the structure of an applied metal block type heat transport device.

0002

[Prior Art] A conventional block-type heat transport device is generally constructed by building a conventional heat pipe in a metal block, which transports heat by phase change and vapor transfer of a two-layer condensable working fluid. There was always something like that.

0003

However, the above-mentioned heat transport device still has the same problems as the conventional heat pipe. That is, as is clear from FIG. 3, which is a cross-sectional schematic diagram showing the operating principle of the conventional heat pipe, the steam flow 7-2 from the heat receiving section 9 of the container 4 toward the heat dissipating section 10.
If the inner diameter of the container 4 is 3 mm or less, the fluid resistance due to the inner wall of the container and the wick 5 will increase rapidly, and the condensation action will be caused by the flow flowing back from the heat dissipating section 10 to the heat receiving section 9 through the inner wall surface of the container and the wick. The flow rate is drastically reduced due to the fact that the resistance due to mutual interference with the liquid 8 increases rapidly. Moreover, if the inner diameter of the container 4 is 3 mm or less, the inside of the pipe is likely to be blocked by the surface tension of the working fluid, and there is a possibility that the steam flow 7-2 may be stopped. These problems severely affect lengths of 300 mm or more when the inner diameter is 3 mm, and when the inner diameter is even smaller, this length becomes shorter at an accelerating rate, until it becomes completely impossible to operate as a heat pipe. Become. Further, the flow of the refluxing working fluid 8 is easily influenced by gravity, and the flow may stop particularly in the top heat mode, and the flow rate may be reduced to 1/2 or less even in the horizontal heat mode.

[0004] Therefore, the problems to be solved by the present invention are as follows. (a) Since it is extremely difficult to manufacture a heat pipe with an inner diameter of 3 mm or less, it is extremely difficult to construct a block-type heat transport device with a thickness of 6 mm or less, considering the wick thickness and wall thickness of the tube. . (b) The performance of a block-type heat transport device incorporating a heat pipe with an inner diameter of 3 mm deteriorates rapidly when the length becomes around 300 mm or more. Moreover, if the inner diameter of the heat pipe is even smaller, it becomes inoperable. Therefore, the thickness is 6mm
It is difficult to construct the following block-type heat transport device with a length of 300 mm or more. (C) A block-type heat transport device incorporating a conventional heat pipe has extremely poor heat transport ability in the top heat mode, and may become inoperable in some cases. Furthermore, the performance in the horizontal heat mode is also reduced to about 1/2.

[0005]

[Means for solving the problem] The basic concept of the means for solving the problem is to configure a heat pipe built into a metal block to transport heat through phase change of the working fluid and vapor transfer. The system will be changed to a heat pipe system that transports heat through axial vibration and gentle circulation of the working fluid.

That is, the heat transport device has a hollow container built into a metal block of a predetermined shape made of a material with good thermal conductivity, and a predetermined amount of two-phase condensable working fluid is sealed in the hollow container. The hollow container is a closed container consisting of a pore group in which a large number of pores are provided in parallel, and a plurality of header holes for connecting the pore groups on each side of the pore group. The pores are characterized in that the inner diameter of the pores is sufficiently small so that a small amount of the working fluid closes the pores due to its surface tension, and the pores always flow in the closed state.

[0007]

[Operation] The thus constituted pore group is considered to be a capillary loop connected by the header cavity, and therefore the entire hollow container is considered to be a loop-type capillary heat pipe. In such a metal block, when heat is supplied to a part of one end and it becomes a heat receiving part, nucleate boiling of the working fluid occurs in the heat receiving part group of the pore group corresponding to the heat receiving part, and Due to the interaction of the nucleate boiling of the heat receiving section group, the working fluid vibrates in the axial direction within the loop-shaped pores and slowly circulates in the direction of least resistance. If heat is supplied to all ends of the metal block, depending on the balance between nucleate boiling in the pore group heat receiving section, gentle circulation of the working fluid may not occur and only axial vibration may occur. .

The axial vibration and gentle circulation of the working fluid within the loop-shaped pores efficiently transport the amount of heat from the heat receiving section (high temperature section) to the heat radiating section (low temperature section). This is exactly the same as the operating principle of the loop-type thin tube heat pipe described in the specification of Japanese Patent Application No. 2-319461, which is currently being filed by the inventor. Further, the principle of heat transport by axial vibration of the hydraulic fluid in the capillary tube is explained in detail in Japanese Patent Publication No. 2-35239, a patent application filed by the University of Florida. FIG. 2 is an explanatory cross-sectional view of a loop-type thin tube heat pipe disclosed in Japanese Patent Application No. 2-319461. container 4
has a sufficiently small diameter so that the hydraulic fluid 6 always flows in the container in a closed state due to its surface tension. Nucleate boiling occurs in the heat receiving section 9 due to the heat received from the heating means 11. The nucleate boiling generated in the heat receiving parts 9-1 and 9-2 causes axial vibration a to occur in the working fluid 6, as well as a gentle circulation flow b. Circulating flow b is vapor bubbles 7-1
is distributed throughout the loop to help generate vibrations. The axial vibration and gentle circulation of the hydraulic fluid transfers heat to the heat receiving parts 9-1 and 9.
-2 to the heat radiation sections 10-1 and 10-2.

Therefore, the amount of heat supplied to the heat receiving portion of the metal block is transported to the remaining parts of the metal block by the above-described action of the pores, raising the temperature of those parts. The effect becomes particularly active when those parts are cooled by a predetermined cooling means.

[0010] Since the heat transport of the metal block carried out in this manner is mainly carried out by the axial vibration of the working fluid within the pore group, the heat transport performance does not change depending on the holding posture of the metal block. do not have. In other words, the performance is the same whether it is in the bottom heat position or the top heat position, and good heat transport is performed. Further, the inner diameter of the pores can be made much smaller than 3 mm, for example, 0.1 mm. Furthermore, since there is no wick, there is no need to consider its thickness. Therefore, the thickness of the metal block is 2m.
It becomes possible to make it as thin as about m. Furthermore, this type of heat pipe can be made sufficiently long without deteriorating its performance, so the length of the metal block is, for example, 1000 mm.
It becomes possible to make it as long as mm.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a flat metal block which is an embodiment of the present invention. (A) is a partially sectional plan view (B) is a partially enlarged side sectional view. The metal block 1 consists of two thin flat plates 1-1 and 1-2, which are welded together and stacked to form one flat metal block 1. flat plate 1
-1 and 1-2 are shaped so that a flat plate-shaped cavity 4 is formed at the seam where they are laminated. In the cavity 4, before the flat plates 1-1 and 1-2 are welded, the thin tube group 2 is inserted or press-fitted in parallel in advance, and when the two flat plates are welded together, the thin tube group 2 is inserted or press-fitted in parallel. 2 and flat plates 1-1 and 1-2 are welded to each other. If the flat plate is sufficiently thick, it may remain inserted or press-fitted, but in the figure, the flat plate is formed extremely thin, so the entire plate is reinforced by lamination welding. The inner diameter of each capillary tube is made sufficiently small so that the hydraulic fluid always flows in the tube in a closed state due to its surface tension. The length of each of the capillary tube groups 2 is slightly shorter than the length of the flat plate-shaped cavity 4, and the surplus space between both ends of the capillary tube group 2 and the flat plate-shaped cavity 4 is configured as a header cavity 3. The thin tube group 2 is constructed in one or two layers. The flat metal block constructed in this manner can be used as a flat heat transport device that is extremely thin, such as 2 mm in thickness, and has sufficiently large width and length.

0012

Effects of the Invention The metal block type heat transport device of the present invention can be constructed in the form of a flat plate with an extremely thin wall and a wide area, and its heat transport performance does not change in any posture. Therefore, the shape of the flat plate does not need to be limited to a simple plane, and its performance can be maintained even if it is configured into a complicated curved surface. In addition, since the structure of the built-in heat pipe is simple and strong, even if the heat transport device has already been formed, it is possible to perform secondary forming by rolling without deteriorating the performance. Further, the shape of the metal block is not limited to a flat plate shape, and can be configured into a cylindrical shape, a cylindrical shape, and various other shapes. Their applications include temperature equalization on a surface, heat connectors, heat absorption plates, heat sinks, fluid transport pipes, heat exchanger piping, and a wide variety of other applications.

[Brief explanation of the drawing]

FIG. 1 (a) is a partially cross-sectional schematic plan view showing the structure of an embodiment of the present invention. (b) Same as above, partially enlarged side view.

FIG. 2 is an explanatory diagram of the operation of the loop-type capillary heat pipe to which the present invention is applied.

FIG. 3 is an explanatory diagram of the operation of a heat pipe to which a conventional metal block type heat transport device is applied.

[Explanation of symbols]

1 Flat metal block 2
Tube group 3 Header cavity 4 Flat plate cavity or container 5
Wick 6 Working fluid 7-1 Steam bubbles 7-2 Steam flow 8 Refluxing working fluid 9 Heat receiving section 10 Heat radiating section 11 Heating means 12 Cooling means a Axial vibration of working fluid b
Gentle circulating flow of working fluid c Direction of transport of heat amount

Claims (2)

[Claims] Claim 1: A hollow container is built into a metal block of a predetermined shape made of a material with good thermal conductivity,
A predetermined amount of two-phase condensable working fluid is sealed in the hollow container, and the hollow container has a pore group in which many pores are provided in parallel, and a pore group on each side of the pore group. It is a closed container consisting of a plurality of header cavities that serve as a pipe header, and the inner diameter of the pores is such that a small amount of working fluid can close the holes due to its surface tension, so that it always flows in a closed state. A heat transport device characterized by a sufficiently reduced inner diameter. Claim 2: The metal block is a flat block with a thin thickness, the hollow container consists of a flat cavity built into the flat block, and the pore group is formed by press-fitting or insertion welding into the flat cavity. Claim: 1. The header cavity is formed by a group of parallel thin tubes in one or two layers, and the header cavity is formed by an extra space before and after the arrangement position of the thin tube group within the flat plate-shaped cavity. 1. The heat transport device according to 1.