JPS58145884A - Long heat pipe for heat transfer - Google Patents

Abstract

PURPOSE:To enable the long distance heat transfer by a structure wherein a large number of thread of ultrafine yarns are densely attached onto the inner peripheral surface of a flexible tubular body and are pressed by a corrugated tube perforated with a large number of small holes in the heat pipe for power cable use or the like. CONSTITUTION:In the heat pipe, the loop flow passage of liquid phase working fluid is formed by the fine gaps between the ultrafine yarns 3, which are made of glass fibers or the like and out of which a large number of threads densely attached along the direction of axis line of the pipe onto the inner peripheral surface of the flexible metallic tubular body 2 are made. Furthermore, the corrugated tube 4 perforated with a large number of small holes 5 is inserted in the inner peripheral side of said ultrafine yarn layer so as to urge the ultrafine yarns 3 against the inner peripheral surface of the tubular body 2 in order to partition the passage of gaseous phase working fluid and of the liquid phase working fluid with the corrugated tube 4. Accordingly, effective capillary tube radii become small and, as a result, high capillarity pressure can be obtained and, furthermore, the pressure losses in the respective passages are small and consequently long distance heat transfer can be made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to heat pipes, and particularly to heat pipes for transporting heat over long distances.

As is well known, heat pipes have a thermal conductivity several tens to ten times higher than sea bream, which has the highest thermal conductivity.
Heat exchangers, large intestine water concentrators, and even l! It is used in various fields such as leprosy, etc., and recently it has also been used for indirect cooling of electric cables.

When indirectly cooling a power cable using a heat pipe, the power cable generates heat over its entire length, so a fairly long heat pipe is required for this purpose, and it is difficult to transport such a long heat pipe. Alternatively, in order to install the heat pipe, it is desirable to wrap the heat pipe around a drum, and it is also necessary to install the heat pipe at different heights to match the power cable.

Therefore, as a heat pipe for indirect cooling of electric power cables, it is desirable to have sufficient flexibility, and it is also required that the capillary pressure is high and the pressure loss of the liquid-phase working fluid and the gas-phase working fluid is small. Ru.

However, conventionally, heat pipes with corrugated tubes as exterior bodies have been known as flexible heat pipes.
- In such a heat pipe, the inner peripheral surface of the full-gate tube is wavy, so even if the wick is made of metal mesh, it is extremely difficult to make the metal mesh tightly adhere to the inner peripheral surface of the full-gate tube. There were various types of 1llI. It is conceivable to make the exterior body a straight metal tube with a certain degree of flexibility in order to achieve this sameness, but if the exterior body is simply made of a flexible metal tube, the heat vibration If the pipe is bent, there is a risk that it may be bent locally, and the wick may be separated from the inner surface of the metal pipe, resulting in narrowing of the gas-phase working fluid or constricting the wick. There are cases where the pressure loss of the working fluid becomes large.

In addition, grooves (groups), metal nets, porous sintered metal, etc. are conventionally known as wicks, but with conventional heat pipes using grooves (groups) as wicks, the capillary snow pressure obtained is low, and the heat It is unsuitable for indirect cooling of electric power cables that need to be transported over long distances. Furthermore, heat pipes with a metal mesh or porous sintered metal as a wick can obtain higher capillary snow pressure than the heat pipes with grooves as a wick. Since the liquid-phase working fluid is contained in the porous sintered metal, the pressure loss of the liquid-phase working fluid is large.Furthermore, when porous sintered metal is used as the wick, the flexibility of the entire heat vibrator is reduced. As a result, it was difficult to indirectly cool the power cable using conventional heat pipes.

This invention has been made in view of the above circumstances, and has sufficient flexibility, high capillary pressure, and low pressure loss of liquid-phase working fluid and gas-phase working fluid. The object of the present invention is to provide a heat pipe that can transport heat over long distances, such as indirect cooling, and even when there is a certain degree of height difference.

In other words, the present invention is characterized in that the exterior body is formed of a flexible tubular body, and a large number of poles/rings that act as a wick are closely arranged on the inner circumferential surface of the tubular body. A corrugated tube having a large number of small holes is inserted into the inner circumferential side of the material wrapper, and the corrugated tube presses the ultrafine wire against the inner circumferential surface of the tubular body.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional view showing one embodiment of the present invention, and FIG. JI2 is a cross-sectional view taken along the line ■-■ in FIG. A large number of ultra-thin wires 3 acting as a wick are closely arranged on the inner peripheral surface of the tubular body 2 along the axial direction of the tubular body 2, and a full gate tube 4 is inserted on the inner peripheral side of the tube 2. Then, the non-condensable gas in the snow-like body 2 is evacuated, and a suitable structure is enclosed.

The tubular body 2 is formed into a tubular shape by, for example, curving both sides of a metal tape in the same direction and welding the ends of the tape against each other, and has flexibility as a whole. Further, the ultra-fine 113 has a diameter of 5~
It is made of glass IIN of about 100μ, carbon fiber, etc., and is flexible in itself, and each a
A fine gap (■) is formed in the (■) of ll along its longitudinal direction, that is, along the axial direction of the front pipe-like body 2, and the gap serves as a transport route for the liquid-phase working fluid and generates capillary pressure. . Furthermore, the corrugated wire 14 is used to press the ultrafine wire 3 against the inner circumferential surface of the tubular body 2, and has a large number of small holes 5 that communicate the inner circumferential side and the outer circumferential side.

Therefore, the corrugated pipe 4 separates a gas phase working fluid flow path and a liquid phase working fluid flow path by the full gate pipe 4 .

However, in the heat pipe 1 configured as above,
Tubular body 2. Since both the ultra-thin wire 3 and the corrugated pipe 4 have flexibility, the entire heat pipe 1 is flexible, so even if it is quite long, the heat pipe 1 can be wound around a drum, for example. When the pipe is bent to fit on the drum, the full-gate pipe 4 guides the entire pipe in an arcuate manner, preventing local bending or constriction. Never. In addition, in the heat pipe 1 described above, when a suitable part of the heat pipe 1 is heated and other suitable parts are cooled, the working fluid evaporated in the heating part is transferred to the full gate pipe 4.
It flows through the small hole 5 formed in the inner circumferential side of the corrugate I4, flows through the inner circumferential side to the cooling section where the ambient pressure is low, and radiates and condenses heat in the cooling section, and the working fluid flows in the heating section. evaporation causes capillary pressure,
The liquid-phase working fluid flows back toward the heating section through the fllFa between the ultrathin wires 3. In this case, the heat pipe 1 above
In this case, the reflux path from the cooling section to the heating section is made straight by the ultra-fine wire 3, so the pressure loss of the liquid-phase working fluid is reduced, and the gap between the ultra-fine wires afQ1 is small. Due to its narrowness, the effective capillary tube radius is extremely small, which increases the capillary pressure. In addition, in the heat pipe 1 described above, the corrugated tube 4 separates the flow path of the gas phase working fluid and the flow path of the liquid phase working fluid. Even if the difference in S degrees between the heating section and the cooling section is large and the flow velocity of the gas-phase working fluid in the tubular body 2 increases accordingly, the liquid flowing in the ultrafine wire 3 The phase working fluid does not scatter, and therefore, in the heat pipe 1 described above, even when the distance between the heating section and the cooling section is long, the liquid phase working fluid can be sufficiently communicated. It can transport heat over long distances, and has a certain heating area.
Heat can be transported even in difficult positions.

In other words, according to the above-mentioned heat pipe, heat can be transported over long distances, it can be bent during transportation, and it can also be bent during installation.
Enables sufficient indirect cooling of power cables that need to be installed at different heights.

As is clear from the above description, according to the heat pipe of the present invention, the exterior body is formed of a flexible tubular body, and the inner peripheral surface of the tubular body is densely coated with ultrafine wires that act as a wick. Furthermore, a corrugated tube having a large number of small holes is inserted into the inner circumferential side of the ultra-fine wire 1, and the ultra-fine wire is pressed against the inner circumferential surface of the tubular body by the tube. Since the effective capillary half diameter becomes smaller due to the use of the wire, high capillary pressure can be obtained, and the flow path of the liquid phase working fluid formed in the ultrathin wire that acts as a wick is straight. In addition, the flow path for liquid-phase working fluid and the flow path for gas-phase working fluid are separated by a full-gate pipe, so the pressure loss of liquid-phase working fluid and gas-phase working fluid is small, and therefore it can be used over long distances. In addition, the exterior body, wick, and corrugated tube are flexible, and the corrugated tube acts as a guide to smoothly curve the entire structure, so it does not bend locally. The entire body can be perfectly curved without any problems, and since the ultra-fine wire is held down by the corrugated tube, the ultra-fine wire is prevented from separating from the inner circumferential surface of the tubular body when it is bent. I can do it. Therefore, overall, the heat pipe of the present invention allows indirect cooling of the power cable to be performed satisfactorily.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■--■ in FIG. DESCRIPTION OF SYMBOLS 1... Heat pipe, 2... Tubular body, 3... Ultrafine wire, 4... Full gate tube, 5... Small hole.

Claims (1)

[Claims] A large number of strips are placed on the inner peripheral surface of the flexible tubular body.
A full-gate tube, which is closely arranged along the axial direction of the tubular body and has a large number of small holes, is placed on the inner peripheral side of the polar matte in order to press the polar matte against the inner peripheral surface of the tubular body. A long heat pipe for heat transport, which is inserted into the tubular body and further includes a working fluid sealed in the tubular body.