JPH0633687B2 - Geothermal utilization heat pipe laying method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a method for laying a heat pipe used for utilizing snowmelt and other geothermal heat.

[Prior art and its problems] For example, in order to protect a power transmission line constructed in a snowfall area from snow damage, heat pipes are laid on the arms and legs of a steel tower that supports the power transmission line, and Attempts have been made to prevent snow cover on the member or reduce the snow pressure on the member by utilizing the above.

The method is that one end of the heat pipe is buried in the soil under the steel tower, the other end is set along the member, and the phase change of the working fluid enclosed in the heat pipe is used to The heat is used to melt snow near the member.

In this case, the heat pipe to be used is calculated by calculating the required length from the underground burial length, the position of the applied member, the length, the routing method, etc. It is necessary to manage the installation, but in terms of manufacturing,
Not only is it uneconomical in construction, but also troublesome.

In addition, if you manufacture it with a long margin, there will be an unnecessary length part above the ground, which may increase heat dissipation, which may reduce the function of the heat pipe. Occurs.

Even if the boring depth when buried underground is shallower than the design value for some reason, the same phenomenon as described above occurs.

[Object of the Invention] An object of the present invention is to propose a method capable of laying a heat pipe economically and efficiently.

[Summary of the Invention] The gist of the present invention is to bend a portion where the function as a heat pipe is unnecessary (hereinafter referred to as an unnecessary portion) after the heat pipe is laid, to a horizontal angle or less near its starting point.

[Embodiment] The present invention will be described with reference to the drawings. In the example shown in FIG. 1, the heat pipe 6 is laid along the member 3 of the leg portion of the transmission line tower, but the upper arm is provided. The same can be applied to the case of laying on a part or the like.

The steel tower leg in the example of FIG. 1 is composed of a main pillar 1, a horizontal member 2, a diagonal member 3, an auxiliary member 4, a foundation 5, and the like, and one end side thereof is placed in the soil near the foundation 5 for a predetermined length. The other end of the buried heat pipe 6 is laid along the diagonal member 3. In this case, although not shown, mounting jigs having a heat insulating function are interposed between the diagonal members 3 and the heat pipes 6 at appropriate intervals to prevent heat in the ground from being dissipated through the diagonal members 3. Has been done.

As the heat pipe 6, a length longer than the length actually required for laying the heat pipe 6 is used. Therefore, the other end side, which is the heat radiation portion after the installation, is too long for the application member 3. Even if the heat pipe 6 having the actually required length is used, the same phenomenon occurs when the depth becomes shallower than the design value due to the circumstances of underground burying. In any case, since the portion longer than the application member 3 is an unnecessary portion, the portion after the heat pipe 6 is laid, and as shown by the solid line in FIG. Bending is performed in the angle range of (θ ≦ 0 °).

Normally, even when it is snowing, the temperature in the ground at a depth of several meters or more from the ground surface is around 10 ° C, so if one end side of the heat pipe 6 is buried as a heat collecting part there, As the temperature on the front side decreases, the heat in the ground is rapidly transported to the ground via the working fluid such as CFC ammonia enclosed therein and radiated. Therefore, even if there is snow at that time and the legs of the tower are covered with snow, the heat pipe 6 continues to radiate heat on the ground, so the snow around the heat pipe 6 is melted and a cylindrical shape is formed around it. A cavity is formed.
If the snow falls and moves, the heat pipe 6
As the snow approaching the snow is gradually blown away, the cavity is gradually expanded in the direction in which the snow sinks or moves, and the load of the snow accumulated on the diagonal member 3 is reduced.

In this case, since the tip portion on the other end side of the heat pipe 6 is bent as an unnecessary portion at an angle less than horizontal near the starting point, the heat radiation in this portion is small and the heat in the ground can be effectively utilized. You can Fig. 2 shows another example of how to bend the part that does not require the function as a heat pipe. When bending the part below the horizontal point near the starting point of the unnecessary part and bending the part following it upward Is. Even in this case, it is possible to reduce the heat radiation in a portion above the bent portion which is below the horizontal.

As the heat pipe 6, as shown in FIG. 3, one in which the working fluid 62 is enclosed in a container 61 with a plastic sheath having a plurality of fine grooves extending in the axial direction on the inner surface is used. As shown in FIG. 4, the heat transfer efficiency is maximum at θ ≧ 2 to 5 °, but heat transfer is not performed at θ = 0. This is because when the working fluid that has vaporized and risen is liquefied in the heat radiating portion and returns to the lower side, the efficiency decreases when θ <2 ° and cannot return when θ <0 °. It was used for indexing the length.

[Effects of the Invention] As is clear from the above, the present invention is a method of bending an unnecessary portion of a heat pipe after installation to an angle below horizontal in the vicinity of its starting point to deteriorate the function of the portion as a heat pipe. Even if a heat pipe having a sufficient length is used, the heat in the ground can be effectively used for protection from snow damage without deteriorating the function of the heat pipe.

Moreover, since it is possible to use a heat pipe with a sufficient length, it is not only easy to manufacture it, but also it is not necessary to strictly install what was manufactured to a predetermined length for construction. There are advantages.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a laying method according to the present invention,
FIG. 2 is a view showing another example of the bent portion, FIG. 3 is a horizontal cross-sectional view of the heat pipe, and FIG. 4 is an explanatory view showing the relationship between the angle of the heat pipe and the characteristics. 1: Main tower pillar, 2: Horizontal material, 3: Tilt material, 4: Auxiliary material, 5: Foundation, 6: Heat pipe.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Shimoshima 3550 Kidayomachi, Tsuchiura City, Ibaraki Prefecture Hitachi Cable Ltd. (72) Inventor Yuji Karashi 3550 Kidayomachi, Tsuchiura City, Ibaraki Prefecture Hitachi Cable Shares Inside the Metals Research Laboratory (72) Inventor Kenichi Kikuchi 3550 Kitayo-cho, Tsuchiura-shi, Ibaraki Hitachi Cable Co., Ltd. (72) Inventor Kenji Kodama 3550 Kitayo-cho, Tsuchiura-shi, Ibaraki Hitachi Cable Co., Ltd. (56) References JP-A-62-123291 (JP, A)

Claims (1)

[Claims] 1. A heat pipe having one end side buried in the ground and the other end side of the heat pipe laid along a member on the ground, and an unnecessary portion on the other end side of the heat pipe near its starting point. A method for laying heat pipes using geothermal heat, which is characterized by bending at an angle less than horizontal with.