JPH0245660Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a device that freezes underground by removing heat from the ground via a heat pipe.

Conventional technology Conventionally, when building underground freezers, constructing structures, and even building strong roadbeds,
Targeted areas are frozen. When performing such freezing in a cold region, it is advantageous in terms of energy cost to utilize the cold heat of the outside air. Conventionally, as a device for this purpose, a steel pipe 1 is used as shown in FIGS. 4A to 4C. A heat pipe can be constructed by burying it underground 2 and by inserting a capillary pressure inside the steel pipe 1, or by injecting an appropriate working fluid after exhausting non-condensable gas such as air. A fin 3 is attached to the upper end protruding from the ground surface to form a heat dissipation section 4, and heat from underground 2 is transported to the ground surface side through the steel heat pipe, and the heat dissipated from the heat dissipation section 4 to the outside air. There are known configurations in which the gas is released and then freezes underground. With such a configuration, a heat pipe with a large diameter and sufficient strength can be made, and therefore a heat transport capacity sufficient for freezing underground 2 can be obtained.

Problems to be Solved by the Invention However, when using the steel pipe 1, it has to be one straight pipe, so it is difficult to increase the surface area per unit length. Therefore, it is possible to increase the area of the outer surface by using a steel pipe with a larger outer diameter, but if the outer diameter of the steel pipe is increased, it will be easier to construct it as a heat pipe, such as transporting it, connecting it, and sealing it. , becomes difficult in geometrical progression as the outer diameter increases, and therefore it is practically impossible to increase the surface area for heat exchange by increasing the outer diameter. In addition, since it is installed almost vertically, it is difficult to supply hydraulic fluid to the entire inner peripheral surface of the part buried underground, resulting in the problem of so-called dryout where the hydraulic fluid dries up in some areas.

This idea was created in view of the above circumstances, and provides a heat pipe type underground freezing device that can easily increase the surface area per unit length and increase the heat exchange area with the surrounding soil. The purpose is to

Means to solve the problem In order to achieve the above purpose, this device has a heat transport capacity that is less than the heat transport capacity required to remove heat from the target underground and freeze it. A heat dissipation section in which a plurality of heat pipes are bundled together, one end of the bundled heat pipes is buried in the target ground, and the other end is kept at a temperature of 0°C or less. It is characterized by being placed in

In this invention, flexible heat pipes can be twisted together, or a corrugated tube can be used as a container as the heat pipe.

Function If there is a temperature difference in a heat pipe, the working fluid inside it will naturally evaporate and transfer heat, so if the underground temperature is 0℃ or higher, the heat pipe will transfer the heat underground to the heat dissipation part. Therefore, the temperature underground is cooled to below 0°C and freezes. In that case, each heat pipe shares the transport of the total amount of heat required for freezing, but each heat pipe independently exchanges heat with the surrounding soil, so the outer circumferential surface of each heat pipe It becomes a heat exchange surface, and it is possible to secure a significantly wider heat exchange area than when using a single heat pipe.

Also, since there is no need to particularly increase the outer diameter of each heat pipe, manufacturing becomes easier.
In particular, if it is flexible, it can be transported while being wound around a drum, making transportation and other handling easier. In order to provide further flexibility, if a heat pipe with a corrugated pipe as a container is used, the unevenness of the inner circumferential surface as it is twisted together forms a liquid reservoir, and as a result, the retention of the working fluid is reduced to the inner circumferential surface. This makes it possible to perform the process over the entire area, thereby eliminating inconveniences such as dry-out.

Embodiments Hereinafter, embodiments of this invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a schematic front view showing an embodiment of this invention, and FIG. 2 is a sectional view taken along the line -- in FIG. 1, and as shown in these figures, three heat pipes 10 are They are twisted together and tied together, and most of the lower end part is buried underground 11 to be frozen, and the upper end part protruding upward from the ground surface is separated into large diameter coils for each heat pipe 10. It is expanded into a shape and serves as a heat dissipation section 12 for the atmosphere below 0°C. Here, each heat pipe 10 is made of a corrugated pipe as a container to provide flexibility, and a heat pipe is charged inside like a normal heat pipe, and an appropriate working fluid is supplied. This is an enclosed configuration.

Therefore, in the freezing device with the above configuration, underground 1
1 and the heat dissipation part 12, the part of the heat pipe 10 buried in the underground 11 acts as a heat input part, absorbs heat from the underground 11, and transfers the heat to each heat source. A pipe 10 carries the heat to a heat dissipation section 12 and discharges it into the atmosphere. That is, the underground is cooled and frozen by the cold heat of the atmosphere via the heat pipe 10. In that case, in the device with the above configuration, the outer peripheral surface of each heat pipe becomes a heat exchange surface with the surrounding soil, so the heat transport capacity is the same as that of the three heat pipes 10 described above. It is possible to secure a wider heat exchange area than a single heat pipe with

Furthermore, when manufacturing the above-mentioned device, it is sufficient to first manufacture the heat pipes 10 one by one and then twist them into a spiral, which makes it easy to manufacture. In particular, in the case of a heat pipe using a flexible container such as a corrugated pipe, it is easier to twist together, it is easier to transport, and the surface area can be increased. Furthermore, since the heat pipe 10 is twisted with respect to the vertical line, when a corrugated pipe is used as a container, some of the irregularities on the inner circumferential surface may collect the working fluid as shown in FIG. As a result, such a liquid reservoir 13 becomes the heat pipe 10.
Since the working fluid is distributed over the entire length of the heat input section, the working fluid that has condensed and liquefied after heat transport can be distributed evenly throughout the entire heat input section, thereby preventing inconveniences such as dryout. be able to.

Note that in the above embodiment, three heat pipes are twisted together, but this invention is not limited to the above embodiment, and may be a structure in which two or four or more heat pipes are tied together. Further, the heat dissipation section may have a configuration in which fins are attached, and furthermore, it may be configured to be cooled not only by the atmosphere but also by using an appropriate cooling device.

Effects of the invention As is clear from the above explanation, this invention has the following effects:
In order to secure the specified heat transport capacity, multiple heat pipes are bundled together, which increases the heat exchange area compared to the case of using a single large-diameter heat pipe, resulting in better cooling characteristics. It is possible to obtain an underground freezing device, and since each heat pipe does not require special specifications, it can be made using an existing one or by a normal manufacturing process, so the manufacturing process of the entire device is reduced. It can be made easy and inexpensive. In particular, a configuration in which flexible heat pipes are twisted together is not only easy to manufacture but also easy to handle, such as transportation.Furthermore, in a configuration in which corrugated heat pipes are twisted together, there is a liquid reservoir inside the entire length. Even if the buried section is long, dryout can be effectively prevented, and a liquid film is formed over the entire length of the heat absorption section of the heat pipe, improving heat transfer coefficient. do.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view partially omitted showing an embodiment of this invention, Fig. 2 is a view taken along the - line in Fig. 1, and Fig. 3 is a partial view of an example using a corrugated heat pipe. , FIGS. 4A to 4C are schematic diagrams of conventional devices. 10...Heat pipe, 11...Underground, 12...
...heat dissipation section, 13...liquid reservoir section.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A heat pipe in which the heat transport capacity of each heat pipe is less than the heat transport capacity required to remove heat from the target underground and freeze it. A heat source characterized in that one end of a plurality of bundled heat pipes is buried in the target ground, and the other end is placed in a heat dissipation section maintained at a temperature of 0° C. or less. Pipe underground freezing equipment. (2) The heat pipe type underground freezing device according to claim 1, wherein the heat pipe has flexibility and each heat pipe is twisted together. (3) The heat pipe type underground freezing device according to claim 2, wherein the heat pipe has a structure in which a corrugated pipe is used as a container.