JPS6039651Y2 - Geothermal heat pipe - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a geothermal heat pipe that is buried underground to utilize geothermal heat.

In recent years, heat pipes with high-performance heat transfer characteristics have been buried underground to utilize geothermal heat to prevent road surfaces from freezing and melt snow.

Conventionally, the installation of a geothermal heat pipe involves digging a hole 2 in the ground 1 by poling, inserting a heat pipe 3 into the hole 2, and then filling a gap 4 between the hole 2 and the heat pipe 3, as shown in Fig. 1. The method used was to fill the sand with sand 5 and fix it in place.

In this way, the heat pipe 3 used for geothermal utilization can have a small diameter because the amount of heat transfer is small, but since it is not possible to dig a small diameter hole 2 by poling, a gap 4 is inevitably formed between the two. Ru.

Therefore, the contact area between the surface of the heat pipe 3 and the high-temperature inner wall surface of the hole 2 becomes narrow, resulting in a problem that the amount of heat transfer decreases.

In addition, the heat pipe 3 is made of a relatively soft metal tube such as copper or aluminum, and has a small diameter and a long length.
When inserted into hole 2, it may hit underground rocks and deform, requiring careful insertion, resulting in poor workability.

The present invention was developed as a result of various studies in consideration of these points, and it is a geothermal heat pipe that increases the thermal contact area with the inner wall surface of the hole, improves the amount of geothermal heat transfer, and has excellent construction workability. It was developed.

That is, in the present invention, a metal tube with both ends closed is buried underground, a heat pipe is inserted into the metal tube with the heat dissipation side protruding from the upper end of the metal tube, and a liquid sealed in the metal tube is used. The heat pipe is characterized in that the endothermic side of the heat pipe is immersed in the heat pipe.

The present invention will be described in detail below with reference to embodiments shown in the drawings.

Figures 2 and 3 show an embodiment of the present invention, in which an iron pipe 6 with its lower end closed is buried underground 1, and a heat dissipation side 3A bent horizontally inside the iron pipe 6 is located at the upper end of the iron pipe 6. It is inserted so that it protrudes from the.

Furthermore, a liquid 7 such as water or antifreeze is sealed inside the iron pipe 6, and the endothermic side 3B of the heat pipe 3 is immersed in this liquid 7.

Further, a support member 9 made of plastic with a groove 8 formed therein is inserted into the bottom of the iron pipe 6, and the lower end of the heat pipe 3 fits into the groove 8, so that the heat pipe 3 does not come into contact with the iron pipe 6. It is supported at its core.

10 is a plug made of plastic, rubber, etc. and is an iron pipe 6
The upper opening of the is closed.

Next, a method of constructing the geothermal heat pipe having the above structure will be explained.

After a hole 2 is dug in the ground 1 by poling, an iron pipe 6 having an outer diameter slightly larger than the inner diameter of the hole 2 is press-fitted and buried while expanding the hole 2A.

A support member 9 made of plastic is inserted into the iron pipe 6 in advance. Next, the heat pipe 3 with the heat radiation side 3A bent horizontally is inserted into the iron pipe 6, and the heat radiation side 3A is bent horizontally into the iron pipe 6. After arranging it so that it protrudes from the upper end, liquid 7 is placed inside the iron pipe 6.
By injecting an appropriate amount of
Let it soak inside.

Next, a stopper 10 is attached to the upper end opening of the iron pipe 6 to close it and fix the heat pipe 3.

After that, soil is poured over the exposed heat radiation side 3A to level the road surface 11, and the construction is completed as shown in FIG. 2.

The geothermal heat pipe configured in this way is made of iron pipe 6.
is press-fitted into the small-diameter hole 2 and buried while being expanded, so that the inner wall of the enlarged hole 2A and the surface of the iron pipe 6 are in close contact, and the outer diameter of the iron pipe 6 is large, making it possible to Compared to a pipe 3 directly buried, the heat transfer surface area is expanded and geothermal heat can be sufficiently absorbed.

The geothermal heat transferred to the iron pipe 6 warms the liquid 7 sealed inside to make hot water, and further heats the endothermic side 3B of the heat pipe 3 immersed therein.

As a result, due to the rapid heat transfer action of the heat pipe 3,
Geothermal heat is transmitted to the heat radiation side 3A buried near the road surface 11 and heats the road surface 11, thereby preventing the road surface from freezing and melting snow.

Therefore, there is no gap 4 between the heat pipe 3 and the hole 2 as in the conventional case, and they are in close thermal contact, and the heat transfer surface area is expanded by the large diameter iron pipe 6, so the amount of geothermal heat transfer is reduced. can be significantly improved.

Furthermore, since only the heat absorbing side 3B of the heat pipe 3 is immersed in the liquid 7, it is possible to prevent heat from being radiated in the intermediate portion leading to the heat radiating side 3A.

Further, since the lower end of the heat pipe 3 is axially supported by a support member 9 made of plastic in which a groove 8 is formed, corrosion of the heat pipe 3 due to contact with the iron pipe 6 can be prevented.

In addition, the iron pipe 6 has a strong outer diameter, thick wall thickness, and high mechanical strength, so it will not deform when press-fitted. Moreover, after the iron pipe 6 is buried in the ground 1 in advance, the heat pipe can be installed inside the iron pipe 6. Since the heat pipe 3 is inserted, the heat pipe 3 is not damaged or deformed, and the construction work is easy.

FIG. 4 shows another embodiment of the present invention, in which a heat insulating material 12 is packed between the upper part of the iron pipe 6 containing the liquid 7 and the open end so as to cover the middle part of the heat pipe 3. It is something that

By filling the heat insulating material 12 in this way, it is possible to more effectively prevent heat radiation in the middle part of the heat pipe 3, and also to block the open end of the iron pipe 6 to prevent earth and sand from flowing into the inside. Can be done.

As explained above, according to the geothermal heat pipe according to the present invention, the thermal contact area between the underground heat pipe and the inner wall surface of the hole is expanded, and the amount of geothermal heat transfer is greatly increased. It has remarkable effects such as improved workability and improved workability.

[Brief explanation of the drawing]

FIG. 1 is a horizontal cross-sectional view showing a conventional geothermal heat pipe buried underground; FIG. 2 is a vertical cross-sectional view showing a geothermal heat pipe according to an embodiment of the present invention buried underground; 3 is a cross-sectional view taken along the line ■--■ in FIG. 2, and FIG. 4 is a longitudinal cross-sectional view showing another embodiment of the present invention. 1...underground, 2,2A...hole, 3...
... Heat pipe, 3A ... Heat radiation side, 3B
... Endothermic side, 4 ... Gap, 6 ...
... Iron pipe, 7 ... Liquid, 9 ... Support member, 10 ... Plug, 12 ... Heat insulation material.

Claims (1)

[Scope of utility model registration request] A metal tube with both ends closed is buried underground, a heat pipe is inserted into the metal tube so that the heat radiation side protrudes from the upper end of the metal tube, and the heat pipe is inserted into the liquid sealed in the metal tube. A geothermal heat pipe made by immersing the heat absorption side of a geothermal heat pipe.