JPS59189251A - Heat pipe - Google Patents

Abstract

PURPOSE:To improve the quantity of heat to be carried of a heat pipe by a structure wherein the effective area serving for evaporation is increased. CONSTITUTION:A liquid return pipe 4 and a circular truncated cone shape liquid collecting plate 5 having a central portion pierced with a hole are arranged in the interior of the outer pipe 3 of a heat pipe 1. Evaporated working medium ascends through the portion pierced with the hole of the liquid collecting plate 5 to a condenser end 1b. The working medium condensed at the condenser end 1b gathers by the help of the curved surface of the liquid collecting plate 5 and flows through a pipe hole 4a down into the pipe 4. In this case, because the liquid return pipe 4 has a sealed lower end and a plurality of intermediate holes 4b arranged on the solar heat receiving side of the wall of the pipe 4, the condensed working medium flows out of the intermediate holes 4b. Because a V shape groove 3a is provided onto the inside surface of the outer pipe 3 along the peripheral direction, the working medium fluid flowed out of the holes 4b is spread by the capillarity of the groove 3a over the whole inside surface of the outer pipe 3, resulting in increasing the area serving for evaporation and consequently improving the quantity of heat to be carried.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat pipe in which a working medium is sealed in a closed hollow container and heat is transmitted through an evaporation and condensation cycle of the working medium.

Conventional configurations and their problems Heat pipes are widely recognized for their excellent heat transfer properties, such as extremely high thermal conductivity and good thermal response, and have recently been increasingly applied to products. Solar heat collectors are no exception, and are widely applied to flat plate and vacuum tube type 2l' solar heat collectors.

Hereinafter, a description will be given of a solar heat collector as an example.

Most of the heat pipes used in solar heat collectors are used in an inclined state due to the installation location. ′! ,
The area of the evaporating part of the solar heat receiving part is much larger than the area of the condensing part. However, in the evaporation section, the area that actually gets wet and contributes to evaporation is small, and most of it is dry, making it impossible for the heat pipe (7) to take full advantage of its excellent heat transfer properties, resulting in a decrease in solar heat collection efficiency. We were connected.

When using a wick, the wetted area increases, but its effectiveness as a heat flow diode, which prevents heat flow in the opposite direction from the condensing part to the evaporating part, decreases, and heat dissipation at night when heat is not collected is reduced. will increase.

OBJECTS OF THE INVENTION The object of the present invention is to increase the effective area contributing to evaporation and to improve the heat transport amount of the heat pipe.

Structure of the Invention The present invention connects a liquid collection plate with the upper end of a liquid return pipe, seals the lower end of the liquid return pipe, and places the liquid on the solar heat receiving side of an outer pipe in which the liquid collection plate and the liquid return pipe are arranged. This is a heat pipe in which intermediate holes provided in the return pipe are arranged close to each other, and grooves are formed in the inner wall of the outer pipe in the circumferential direction. Further, the heat pipe is provided with a spiral groove in the circumferential direction on the inner surface of the outer tube.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a sectional view of a solar collector using the heat pipe of the present invention, Fig. 2 is a sectional view of a heat pipe according to an embodiment of the present invention, and Fig. 3 is a detailed view of part A in Fig. 2. It is. 1st
As shown in the figure, large sunlight 2
When this occurs, the working medium evaporates into a gas and moves to the condensing section 1b due to the vapor pressure difference. The condensed working medium flows down inside the heat pipe 1 due to gravity. At this time, in the present invention, as shown in FIG. A truncated cone-shaped liquid collecting plate 6
is arranged, and the evaporated working medium passes through the penetrating portion of the liquid collecting plate 6 and rises to the condensing section. As shown in FIG. 3, the liquid collecting plate 5 is arranged with an inclination such that the joint part with the pipe opening 4a of the axillary return pipe 4 is at a lower position, so that the working fluid condensed in the condensing part 1b The liquid collects along the curved surface of the liquid collecting plate 5, passes through the pipe opening 4a, and flows down inside the liquid return pipe 4. At this time, since the lower end of the liquid return pipe 4 is sealed 1 and a plurality of intermediate holes 4b are provided on the solar heat receiving section side of the tube wall, the condensed working medium overflows and flows out from the intermediate holes 4b. A V-shaped groove 3 is formed on the inner surface of the outer tube 3 along the circumferential direction.
Since the groove 3a is provided, the working medium liquid that flows out flows into the groove 3a.
The capillary phenomenon spreads and wets not only the bottom but also the entire surface of the inner surface of the outer tube 3, increasing the area that actually contributes to evaporation in the evaporation section and improving the amount of heat transport. In the embodiment described above, the groove on the inner surface of the outer tube 3 is V-shaped, but the same effect can be obtained with other shapes as well.
If the groove is formed in a spiral shape, the time during which the working medium is in contact with the pipe wall becomes even longer.

5. - Effects of the invention In the heat pipe of the present invention, when the working medium condensed in the condensing section flows down, it is possible to increase the wetted area with the outer pipe wall that contributes to evaporation, thereby improving the amount of heat transport. It has excellent heat transfer properties.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a solar heat collector using a heat pipe according to an embodiment of the present invention, FIG. 2 is a sectional view of a heat pipe according to an embodiment of the present invention, and FIG. 3 is an A in FIG. 2. FIG. 3...Outer tube, 3a...-groove, 4...
・・Liquid return pipe, 4a・・・・−・Pipe opening, 4b・・・・−
- Intermediate hole, 5... truncated conical body. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] a liquid collection plate to which refrigerant vapor adheres and liquefies; a liquid return pipe whose upper end communicates with the liquid collection plate and whose lower end is sealed; A heat pipe comprising an outer tube for housing the tube, and an intermediate hole provided in the liquid return tube wall is arranged adjacent to the solar heat receiving side of the outer tube.