JPH054593B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an industrial field in which geothermal heat is extracted to the ground by a heat transfer means and the heat is utilized for, for example, snow melting, power generation, etc.

Conventional technology In the conventional field of application of this type of industry, when pumping underground steam or hot water, for example
Several tens to hundreds of steel or alloy steel pipes of approximately 500 m in diameter are connected by fitting male and female screws at each end, inserted into a well, and buried underground. In this case, the pipe itself can sufficiently withstand the hanging load and external pressure applied in the radial direction of the pipe deep underground;
In terms of workability, it has drawbacks such as difficulty in making on-site connections and processing the inside of the pipe. On the other hand, in order to improve workability on-site, products are semi-finished or completed in advance at the factory, and thin-walled corrugated heat pipes are used for flexibility and transport and handling. It is used as a so-called thermosiphon, and is buried 200 to 5,000 meters underground, not only in areas where steam and hot water spews out, but also in areas where these do not spew out, using heat pipes to pump up only the underground heat, and extracting underground steam. There is an idea to extract geothermal heat from the ground without depleting hot water or hot water.

However, in this case, there are the following drawbacks.

(1) Since a long pipe of several thousand meters is suspended from the ground to the ground and buried, its own weight acts on the long pipe, causing the corrugated heat pipe to stretch, resulting in corrugated corrugation. The pipe may become partially smoothed or the pipe may break.

In particular, when the waveform becomes smoother, the heat transfer characteristics of the heat pipe begin to vary in the longitudinal direction.

(2) Underground, external pressure acts in the radial direction of the pipe,
The pipe is crushed.

In this case, generally depth (m) x 0.12 (Kg/
cm ² ) or more, and at a depth of several thousand meters, the pipe is exposed to an external pressure of several hundred kg/cm ² , so if the pipe is thin, it is likely to be crushed.

Means for Solving the Problems The present invention has been made in order to solve the above problems.

In other words, it is an effective method for efficiently extracting geothermal heat to the ground using thin-walled long corrugated heat pipes placed vertically deep underground, as described below.

(1) A corrugated type heat pipe with a corrugated surface in the longitudinal direction, sealed at both ends, and a working fluid sealed inside, in which a rope that passes through the inside in the longitudinal direction is fixedly fixed at both ends. heat pipe.

(2) A spiral reinforcing body is installed along the entire length of the corrugated heat pipe or at a certain position in contact with the inner wall surface of the pipe.

(3) A condensate receiver was attached to the rope that passes through the corrugated heat pipe in the longitudinal direction.

(4) Wicks were attached to the entire length or at a certain position of the rope that penetrates the corrugated heat pipe in the longitudinal direction.

(5) A wick is interposed between the inner wall of the corrugated heat pipe and the reinforcing body.

(6) Combining each of the above items to achieve a synergistic effect.

Function (1) By providing a rope that penetrates the center of the corrugated heat pipe, it is possible to absorb the sagging due to the pipe's own weight when the pipe is installed underground, and it is possible to prevent the waveform from becoming smooth in the longitudinal direction of the surface. Also, the thermal expansion of the rope material is different from that of the corrugated heat pipe in the longitudinal direction, but since the corrugated heat pipe has a wave shape in the longitudinal direction,
It can follow the thermal expansion of the rope.

(2) By providing a spiral reinforcing body in contact with the inner wall of the corrugated heat pipe, the pipe will not be crushed even if it is subjected to radial pressure deep underground when it is installed underground. Never.

In addition, the winding directions of the corrugations of the reinforcing body and the corrugated heat pipe are the same, and the winding pitch of the reinforcing body is the same as or smaller than the corrugated pitch of the corrugated heat pipe, thereby increasing the flexibility of this pipe. It maintains flexibility and can absorb both expansion and contraction caused by thermal expansion.

Furthermore, if the winding directions of the corrugations in the reinforcing body and the corrugated heat pipe are opposite, the winding pitch of the reinforcing body may be arbitrary. It does not fall into the shaped groove, and also has the effect of being wound in the same direction as described above.

(3) By installing an appropriate number of condensate receivers at certain locations on the rope that passes through the center of the corrugated heat pipe, the condensate is cooled at the top of the pipe.
This receives the condensed liquid dripping, and the liquid in this part evaporates as appropriate and continues to move to the upper part, so no dryout occurs.

(4) Similarly, a capillary action wick is provided along the entire length of the rope that passes through the center of the corrugated heat pipe, or at a certain location, and this wick actively retains the condensate, and evaporates from this part. to prevent dry out.

(5) In the same way, a reinforcing material such as a wire mesh is attached to the entire length of the inner wall of the corrugated heat pipe or at a certain point, and the condensate is retained by the wick and evaporated in this area to prevent dryout.

Embodiment FIG. 1 is a partially cutaway sectional view of a conceptual diagram showing an outline of the present invention.

Reference numeral 1 denotes a corrugated heat pipe according to the present invention, which maintains flexibility, and has an upper end partially located above ground and a lower main part buried underground 100 over a distance of about 200 to 3000 m.

The lower part is the ripening part and this heat is taken out from the upper part.
This pipe is made of metal pipes such as steel, copper, aluminum, and stainless steel with an inner diameter of about 50 to 300 m.
The surface shape is formed in a so-called corrugated shape with a corrugated shape 101 in the longitudinal direction, and a working fluid 102 such as Freon (trademark) is sealed inside the pipe.

Here, the waveform of the surface shape may be a spiral shape or a flat plate shape which is a non-spiral shape.

Reference numeral 2 denotes a tension cable, which is made of stranded wire such as steel, and passes through the center of the corrugated heat pipe in the longitudinal direction, and both ends of the cable are connected to an upper terminal fitting 201 and a lower terminal fitting 202, respectively, in a factory, for example. The position is adjusted and fixed and sealed to these terminals by crimping, welding, etc. The upper end fitting 201 consists of a disc-shaped sealing part having a center hole and a cylindrical boss part having a center hole coaxially therewith.

The upper end of the corrugated heat pipe 1 is sealed in the sealing part by welding or screw engagement,
The upper end of the tension cable 2, which has passed through the sealing part at the boss part, is fixed by a fixing means such as crimping to sufficiently hold the hanging load.

This upper terminal fitting 201 further includes a hanging fitting 20.
3 is coaxially fixed by crimping screw engagement or the like. The hanging fitting 203 has a hanging hole 20.
4 is provided for use during transportation and installation.

Similarly, the lower end of the tension cable 2 is attached to the lower terminal fitting 2.
02, and similarly seals the lower end of the corrugated heat pipe.

The boss portion is protected by a cap metal fitting 205.
Note that the means for fixing the upper and lower ends of the tension cable 2 are not limited to those described above.

Reference numeral 3 denotes a reinforcing body, which is made of a metal strip such as steel, and is spirally wound at a constant rate. It is attached to the inner wall of the corrugated heat pipe 1 so as not to slip down. For installation, for example, this reinforcing body is cooled and shrunk in advance.
After installation, it may be expanded to its normal size at room temperature. The mounting position may be over the entire length in the longitudinal direction or may be at a specific portion.

It is particularly desirable to use it on the inner wall of a corrugated heat pipe deep underground.

When the corrugated heat pipe 1 has a spiral shape, the winding pitch may be the same as or smaller than the wavy pitch of the corrugated heat pipe 1.

The cross-sectional shape of the metal strip constituting the reinforcing body 3 may be any suitable shape such as circular or rectangular, as long as it does not impair the flexibility of the corrugated heat pipe 1.

Reference numeral 4 denotes a condensate receiver, which is a dish-shaped, bowl-shaped, etc. member, that is, a concave surface formed on the upper side, and is pivotally supported and attached to the tension cable 2 through a central hole, for example. Their size and number are determined by taking into consideration the inner diameter, length, and heat transport capacity of the corrugated heat pipe.

The attachment positions may be provided continuously or at intervals over the entire length of the tension rope 2 or at certain locations, that is, specific locations. This installation can easily be done in the factory.

Further, the shaft support means is not limited to the tension rope 2, but may be a rope similarly provided to penetrate inside the corrugated heat pipe. Here, rope materials include not only tension ropes but also hemp ropes, plastic fibers,
A rope made of twisted carbon fibers with high mechanical strength such as tensile strength.

Reference numeral 5 denotes a wire, which is made of wire mesh, ultra-fine wire, etc., and is appropriately provided on the tension rope 2, for example.

The wicks 5 may extend over the entire length of the tension rope 2, or may be provided continuously or at intervals at certain locations. Here, the wick may be similar to the tension rope 2 or may be embedded within the tension rope 2.

Furthermore, instead of the tension rope 2, the entire length of a rope similar to this may be provided at specific locations as appropriate.

6 is a corrugated heat pipe 1 in the same manner.
The wick is interposed between the inner wall and the reinforcing body 3, and is made of wire mesh, ultra-fine wire, etc. This wick 6 may be sandwiched between the inner wall of the corrugated heat pipe 1 and the reinforcing body 3 by utilizing the contact pressure between them, or the wick 6 may be wrapped around the metal strip of the reinforcing body 3 in advance and then spirally formed. It may also be constructed by winding it in a constant manner.

Similarly, the wick 6 may extend along the entire length of the inner wall of the pipe, or may be provided at a specific location as appropriate.

206 is a nozzle for evacuation and liquid injection, and is a nozzle for vacuuming and injecting liquid into the corrugated heat pipe 1.

FIG. 2 is an explanatory diagram of an embodiment of the present invention, in which a corrugated heat pipe 1 is supported and fixed to an above-ground structure 10.

Reference numeral 11 is a geothermal extraction pipe from which geothermal heat is transmitted to a cooler (not shown, the same applies hereinafter).

12 is a liquid return pipe in which steam is cooled by a cooler;
It is condensed and refluxed into the corrugated heat pipe 1.

Reference numeral 13 denotes a branch pipe, which is used as a means for vacuum evacuation, liquid injection, pressure gauge safety valve work, and monitoring.

Furthermore, it goes without saying that the corrugated heat pipe 1 may be appropriately subjected to protective treatments such as partial insulation and anti-corrosion treatment as necessary.

In the embodiment described above, an example was shown in which the corrugated heat pipe of the present invention was vertically buried underground, but the embodiment is not limited to this.

That is, for example, (1) it can be placed not only underground but also underwater, and (2) it can be placed not only vertically but also at an angle. For example, if there is an obstacle underground, the cable may be installed at an angle to avoid this area. (3) May be used horizontally.

For example, when a tension rope is installed inside a corrugated heat pipe and it is used in this horizontal direction, even if thermal expansion force is applied in the longitudinal direction, the tension rope controls its behavior, and the corrugated heat pipe Since deformation of the heat pipe is prevented, heat transfer characteristics are maintained well.

Effects of the Invention The corrugated heat pipe of the present invention makes it easier to produce longer pipes in a factory than with conventional pipe construction methods, and it is easy to install the pipes over a wide range of sites. It is possible to provide a heat transfer means that can stably transfer heat without impairing its various characteristics, especially its heat transfer characteristics.

In other words, it is easy to attach various materials to a long pipe in a factory, and it is easy to carry it out at the transportation site.The action of these materials prevents (1) overstretching of the pipe due to its own weight and smoothing of the waveform; , (2) crimping of the pipe by external pressure in the radial direction at the bottom of the pipe, and (3) heat transfer means that can prevent dryout by condensate receiver and wick arrangement, etc. can be provided, and in the field, this pipe is used in the simplest case. It has the advantage that it is only necessary to install it directly into the excavated hole.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view of a conceptual diagram of an implementation of a corrugated heat pipe according to the present invention, and FIG. 2 is an explanatory diagram of an embodiment of a corrugated heat pipe according to the present invention. In the figure, 1: corrugated heat pipe, 2: tension rope, 3: reinforcing body, 4: condensate receiver, 5 and 6: wick.

Claims (1)

[Claims] 1. In a corrugated heat pipe whose surface is formed into a wave shape in the longitudinal direction, both ends are sealed, and a working fluid is sealed inside, a rope passing through the inside in the longitudinal direction is fixedly engaged at both ends. Corrugated heat pipe. 2 In a corrugated heat pipe whose surface is formed into a wave shape in the longitudinal direction, both ends are sealed, and a working fluid is sealed inside, a spiral reinforcing body is attached to the inner wall surface of the pipe along the entire length in the longitudinal direction or at a certain position. A corrugated heat pipe. 3. Claim 2, characterized in that the corrugation of the reinforcing body and the corrugated heat pipe are wound in the same direction, and the pitch of the reinforcing body is the same as or smaller than the pitch of the corrugated heat pipe. Corrugated heat pipe as described in section. 4. The corrugated heat pipe according to claim 2, wherein the corrugation of the reinforcing body and the corrugated heat pipe are wound in opposite directions. 5. In a corrugated heat pipe whose surface is formed into a wave shape in the longitudinal direction, both ends are sealed, and a working fluid is sealed inside, at least one of the ropes provided longitudinally through the central part of the pipe. A corrugated heat pipe with condensate receivers installed at certain points. 6 In a corrugated heat pipe whose surface is formed into a wave shape in the longitudinal direction, both ends are sealed, and a working fluid is sealed inside, at least one of the ropes provided longitudinally through the central part of the pipe. Corrugated heat pipe characterized by having a capillary action wick in the part 7 A corrugated heat pipe whose surface is formed into a wave shape in the longitudinal direction, both ends are sealed, and a working fluid is sealed inside. , a corrugated heat pipe in which a wick is interposed between the inner wall surface of the pipe and a reinforcing body attached to the entire longitudinal length of the inner wall surface of the pipe or at a certain point.