JPH07330079A - Structure for preventing dissolution of compressed air stored in compressed air storage tank and installation method thereof - Google Patents

Abstract

PURPOSE:To obtain a structure for preventing dissolution of compressed air stored in a compressed air storage tank, that can easily prevent stored compressed air from dissolving into confined water by a simple structure without using a forced head system. CONSTITUTION:A dissolution-preventing structure 10 according to the invention is used in an underground storage tank 11 of a pressure compensatory type for storing an excess electric power, such as a night electric power, deep under the ground as compressed air. On an upper end of the underground tank 11, an air feed pipe 12 is vertically provided upward from the upper end to the ground. In the air feed pipe 12, a water feed pipe 13 opened to the bottom of the underground tank 11 at the lower end thereof is provided for supplying confined water 25 for compensating a pressure to the lower part of a storage space 14. The dissolution-preventing structure 10 is composed of a film structure 15 covering a water surface of in the underground tank 11. The film structure 15 is formed by laminating a silicone liquid film 16 on a synthetic resin film 17 as a composite film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing the dissolution of stored compressed air in a compressed air storage tank and a method of installing the dissolved prevention structure. In particular, the pressure for storage is compensated by pressurized water sent into the tank. The present invention relates to a stored pressure air dissolution preventing structure for preventing stored pressure air from being dissolved in pressurized water due to its pressure, which is used in a water pressure compensation type storage tank for storing compressed air, and a method of installing the dissolution prevention structure.

[0002]

2. Description of the Related Art In recent years, various underground tanks have been developed as facilities for storing surplus power such as late-night power as compressed air such as compressed air and other facilities for storing high-pressure gas. That is, according to the underground tank for storing such compressed air, by providing the underground tank in the deep underground, the pressure resistance for resisting the internal pressure of the compressed air that is fed by the air supply pipe and stored inside, It is not compensated by earth pressure or groundwater pressure applied to the underground tank from the surrounding ground, thereby reducing the tensile stress generated in the underground tank and simplifying the structure of the underground tank.
Enables effective use of underground space.

A so-called water pressure compensating underground storage tank is known as an underground tank for storing such compressed air. This water pressure compensation underground storage tank
The upper pipe, which consists of a reservoir, a lake, a river, an underground river, etc. above the underground tank, is connected to the lower space of the underground tank by a water pipe, and the head difference between the water level in the underground tank and the water level in the upper tank By filling the water pipe with the accompanying pressurized water, the compressed air storage space in the underground tank is pressed from below via the water surface by the pressure due to the head difference, and the desired pressure for compressed air storage is always maintained. It is intended to be compensated.

[0004]

However, according to such a conventional water pressure compensating type underground storage tank, the compressed air or the like to be stored has a desired pressure due to the pressurized water via the water surface in the tank. Since it is pressed by, the pressure air is easily dissolved in the water under pressure due to such pressure.Therefore, especially when the pressure air is used, the dissolved pressure air flows back upward in the water pipe due to buoyancy and bubbles on the ground. There is a case where energy is lost due to a large amount of water flowing out, and the inside of the tank is rapidly depressurized, so that the tank cannot be opposed to the ground pressure from the surrounding ground and the tank is damaged.

As a means for preventing the dissolution of such compressed air in the pressurized water and the accompanying loss of energy, conventionally, as shown in FIG. 11, a water supply pipe 51 into the underground tank 60 is used. U-shaped tube 5 pushed into the lower part of the head as a water head tube
By providing No. 3, the method of preventing the backflow of the dissolved pressure air and the diffusion into the atmosphere has been adopted.

However, such a conventional U-shaped tube 5
In the method of preventing the pressure air from being dissolved by the method 3, the underground tank 6 is used for the work of providing the U-shaped pipe 53 on the water supply pipe 51.
Since it is necessary to dig further into the ground below 0, it takes time and labor, and in particular, a vertical hole is drilled deep in the ground in a submerged state, and an unmanned underground tank is installed without workers entering the vertical hole. When constructing an underground tank by the construction method described above, it is difficult to provide the water pipe 51 with the U-shaped pipe 53.

Therefore, the present invention has been made in order to solve the above problems, and facilitates the dissolution of stored compressed air into pressurized water with a simple structure without adopting the conventional so-called forced head system. An object of the present invention is to provide a structure for preventing stored compressed air from being dissolved in a compressed air storage tank that can prevent the stored compressed air.

Another object of the present invention is to provide a method for installing a dissolved prevention structure, which allows the stored compressed air dissolution prevention structure to be easily installed unattended without an operator directly entering the deep underground. And

[0009]

The present invention has been made in view of the above object, and its gist is to compensate the pressure for storage by pressurized water such as water or seawater sent into a tank. A structure for preventing the stored compressed air from being dissolved in the compressed water due to the pressure, which is used in a storage tank of a water pressure compensating system that stores compressed air. A structure for preventing dissolution of stored compressed air in a compressed air storage tank, which is characterized by comprising a curtain structure for covering the container and blocking contact with the stored compressed air.

Further, in the structure for preventing the dissolution of stored compressed air according to the present invention, it is preferable that the curtain structure is composed of a liquid curtain of silicon such as silicon oil floating on the surface of the pressurized water.

Further, in the structure for preventing dissolution of stored compressed air according to the present invention, the curtain structure is an ethylene vinyl alcohol copolymer (hereinafter referred to as "EVOH") floating on the surface of the water to be pressurized.
It can also be constituted by a synthetic resin curtain containing.

Furthermore, in the structure for preventing the dissolution of stored compressed air according to the present invention, the curtain structure is a composite structure in which a liquid curtain of silicon such as silicon oil and a synthetic resin curtain containing EVOH, which float on the surface of the water to be pressurized, are laminated. It may be composed of a curtain.

Further, in the structure for preventing the dissolution of stored compressed air according to the present invention, the water pressure compensating tank is a tunnel type compressed air tank extending in the lateral direction, and the curtain structure is arranged so that the cavity of the tunnel is vertically moved. It is also possible to use an elastic curtain that is swellable up and down and is provided around the wall surface of the tunnel so as to be blocked and divided.

Another aspect of the present invention is an installation method for installing a stored compressed air dissolution preventing structure comprising a curtain structure for covering a pressurized water surface in the compressed air storage tank.
By refilling the inside of the compressed air storage tank with water and filling the inside of the water supply pipe and the air supply pipe provided in communication with the tank and the ground, by pumping a certain amount of replenishment water through the water supply pipe, The filling water in the air feeding pipe communicating with the water feeding pipe through the storage tank is lowered, and the membrane member constituting the membrane structure is inserted into the upper portion of the air feeding pipe where the filling water is lowered, and thereafter, above the air feeding pipe. The air is closed and the compressed air is fed into the air supply pipe, so that the compressed air pushes down the membrane member toward the inside of the tank together with filling water, and the membrane member is pressurized water for pressure compensation in the tank. The method for installing a structure for preventing the dissolution of stored compressed air in a compressed air storage tank, characterized in that the structure is installed as a membrane structure.

[0015]

According to the structure for preventing the dissolution of stored compressed air in the compressed air storage tank of the present invention, the curtain structure covering the water surface in the underground tank blocks direct contact between the compressed air and the pressurized water. In addition, the compressed air is prevented from passing through, thereby preventing the compressed air such as compressed air from being dissolved in the pressurized water.

Further, if a synthetic resin curtain containing silicon or EVOH is used as a curtain structure for covering the water surface in the underground tank, it can be stored in the tank in spite of a simple structure in which these are floated on the water surface. The boundary between the compressed air and the pressurized water can be effectively blocked.

Further, when the water pressure compensation tank is a laterally extending tunnel type compressed air tank,
If the curtain structure is composed of an elastic curtain that is vertically swellable and is provided by fixing the periphery to the wall surface of the tunnel so as to divide the tunnel cavity into upper and lower parts, the water surface over a wide range can be followed up and down. It can be stably covered.

According to the method for installing the dissolved prevention structure of the present invention, the worker enters the underground tank with a curtain structure made of a synthetic resin curtain containing silicon oil, EVOH, etc. for covering the water surface in the underground tank. It can be easily installed in a floating manner without any work from the ground.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a dissolution preventing structure 10 according to this embodiment, which stores excess power such as night power as compressed air, that is, compressed air in an underground storage tank 11 provided deep underground, and stores the power when power is consumed in the daytime. The so-called CAES (Compressed Air Energy Storage) that enables the compressed air to be taken out and generated and reused
It shows an example adopted in the system.

That is, the underground storage tank 11 is, for example, at a depth of about 150 m from the ground, for example, in a vertical hole formed by excavation in the ground as shown in Japanese Patent Application No. 6-44205 filed by the applicant of the present application. Fill a filling liquid to hold the wall surface, insert a mold film consisting of a double structure bag into this vertical hole, set the concrete inside the mold film and let it settle to reach the bottom of the vertical hole. By making it bottom, it can be installed by the method of constructing a concrete underground tank.

The vertical hole in which the underground tank 11 is installed has, for example, Japanese Patent Application No. 5-334 filed by the applicant of the present application.
As shown in No. 554, the heavy mud water pressure is applied to the underground tank 11 to resist the internal pressure of the compressed air stored in the underground tank 11, thereby stabilizing the underground tank 11. Has been planned.

Furthermore, at the upper end of this underground tank 11,
An air supply pipe 12 extending upward from the upper end to the ground is provided, and a lower end of the air supply pipe 12 opens downward to a bottom portion of a storage space 14 of the underground tank 11 and upwardly. A water pipe 13 extending up to the ground and extending to the ground is provided. Here, the air supply pipe 12 feeds and stores compressed air generated by a compressor or the like, that is, compressed air into the underground tank 11 and stores the stored compressed air as electric power in order to store surplus electric power such as nighttime electric power as compressed air. Compressed air is fed to a gas turbine or the like installed on the ground when properly taken out for use.
On the other hand, the water pipe 13 communicates with an upper reservoir such as a reservoir provided on the ground to feed the stored water of the upper reservoir to the underground tank 11, and also to detect the head difference between the water level in the reservoir and the water level in the underground tank 11. The pressurized water 25 of the tank 11 is kept filled in the water supply pipe 13 so that a predetermined hydrostatic pressure due to the head difference is applied to the tank 11 via the water surface in the tank 11.
The internal storage space 14 for compressed air is loaded. That is, by the action of the water supply pipe 13, the underground tank 11 functions as an underground storage tank 11 of a water pressure compensation system in which the pressure due to the head difference is compensated.

The storage compressed air dissolution preventing structure 10 of this embodiment is composed of a membrane structure 15 provided so as to cover the water surface in the underground tank 11. That is, the film structure 15 is the silicon liquid film 1 made of silicon oil or the like.
6 and the synthetic resin film 17 are laminated as a composite film. In addition, as shown in FIG. 2, the synthetic resin film 17 includes a slide ring 26 that can slide up and down along the outer circumference of the water pipe 13, and a supporting frame rotatably attached to the slide ring 26. 27, a sheet-shaped EVOH film 18 supported by the supporting bone 27 in a circular shape and foldable,
It is composed of a large number of spherical silicon 19 attached to the surface of the VOH film 18, these supporting bones 27, the EVOH film 18, and a bag body 20 made of Teflon, polyethylene or the like for enclosing the spherical silicon 19. In addition, E
The use of spherical silicon 19 or the like in combination with the VOH film 18 is intended to give the synthetic resin film 17 buoyancy for floating on the pressurized water 25.

According to the dissolution preventing structure 10 having such a structure, the dissolution preventing structure 10 can prevent the compressed water from being stored in the underground tank 11 or discharged from the underground tank 11. By sliding up and down following the vertical movement of the surface and constantly maintaining the state of covering the water surface to avoid contact between the water surface and the compressed air in the storage space 14, compressed air, that is, compressed air is covered. Prevents dissolution and dissolution in pressurized water. In addition, in this embodiment, as the film structure 15 constituting the dissolution preventing structure 10, a case in which a silicon liquid film 16 and a synthetic resin film 17 are laminated as a composite film is used. As shown in (b), the silicon liquid film 16 can be used alone, and the synthetic resin 17 including the EVOH film 18 can also be used alone. Further, since the EVOH film has a large effect of blocking air and water, when the EVOH film and silicon are stacked and used, the thickness of the film structure 15 can be made smaller than that when, for example, the silicon liquid film 16 is used alone. Therefore, the storage space 14 can be used more effectively.

Then, the dissolution preventing structure 10 of this embodiment
To install the water on the surface of the pressurized water 25 in the underground tank 11, for example, as shown in FIG. 3A, first, the stored water is fed from the upper pond to fill the inside of the compressed air storage tank 11. The inside of the water supply pipe 13 and the air supply pipe 12 is filled with water. Next, as shown in FIG. 3B, by pumping a fixed amount of replenished water by the pump 24 through the water supply pipe 13, the water supply pipe 13 and the storage space 14 of the storage tank 11 are collected.
The filling water in the air supply pipe 12 communicating with each other is reduced. Next, as shown in FIG. 3C, the silicon liquid film 16 constituting the composite film is formed in the upper void portion of the air supply pipe 12 in which the filling water is lowered.
Silicon 21 as a film member for and the synthetic resin film 17 in the folded state are inserted and arranged. Next, FIG.
As shown in (d), the upper end of the air supply pipe 12 is connected to the pressure lid 22.
After shutting off by means of pressure, compressed air is pumped into the air pipe 12 using a compressor or the like, and along with this, the filled water is pumped up from the water pipe 13 so that the silicon 21 and the synthetic resin film 17 in the folded state are stored in the underground tank 11. 3), the synthetic resin film 17 in the folded state is unfolded in the underground tank 11, and as shown in FIG. 3 (e), on the surface of the pressed filled water, that is, the pressurized water 25,
A film structure 1 including a silicon liquid film 16 and a synthetic resin film 17.
Float 5 Then, if the compressed air is further fed from the ground, as shown in FIG. 3F, the compressed air for power storage is stored in substantially the entire storage space 14 of the underground tank 11.

That is, according to the above-mentioned installation method, the underground tank 11 provided in the deep underground portion is provided only by the work from the ground without the workers entering the underground tank 11.
The dissolution preventing structure 10 can be easily installed therein.
Further, as the film structure 15, a silicon liquid film 16 or EVO
Even when each of the synthetic resin films 17 including the H film 18 and the like is used alone, the dissolution preventing structure 10 can be easily installed in the underground tank 11 according to the same steps as the above-described method.

The dissolution preventing structure 1 according to this embodiment
0 can also be easily taken out from the underground tank 11. That is, as shown in FIGS. 4A and 4B, the air supply pipe 1 is supplied while supplying replenishment water from the water supply pipe 13 into the underground tank.
When the pressured air is taken out from 2, the membrane structure 15 is pushed upward, and the synthetic resin film 17 is folded and passes through the air supply pipe 13 toward the ground, whereby it can be easily removed from the underground tank 11. it can.

FIG. 5 shows another embodiment of the present invention. The dissolved prevention structure 30 of this embodiment is installed in a tunnel-type underground tank 31 formed in a bedrock tunnel 32, for example. That is, the underground tank 31 is formed by lining the inner wall surface of the tunnel 32 with concrete 35, and an air supply pipe 33 and a water supply pipe 34 are provided so as to communicate with the ground by using a vertical shaft or the like used during tunnel excavation. At the same time, the water pipe 34 extends below the underground tank 31 and opens at the bottom surface of the underground tank 31, so that the pressurized water 25 can be supplied to the lower half portion of the underground tank 31.

Then, the dissolution preventing structure 30 of this embodiment
Is composed of, for example, a vertically swellable elastic film 36 made of, for example, rubber or synthetic resin, which is wound around the lining concrete 35 and fixed around the wall surface of the tunnel 32. As shown in (A) to (C), the cavity of the underground tank 31 is divided into upper and lower sections so that compressed air is supplied to the upper section and compressed water 25 is supplied to the lower section. By swelling up and down with the vertical movement of the pressurized water surface due to the storage and removal of compressed air,
The state in which the contact between the compressed air and the pressurized water 25 is cut off is easily maintained. That is, according to this dissolution preventing structure 30, it is possible to stably cover the water surface over a wide range of the tunnel type underground tank 31 by following the vertical movement of the water surface. Even in such a tunnel-type underground tank 31, a film structure can be formed by the silicon liquid film 16 or the like floating on the surface of the water under pressure described above.

Next, an example of an experiment conducted for demonstrating the action and effect of the storage pressurized air dissolution preventing structure of the present invention will be shown.

[Experimental Example 1] Using an experimental apparatus 43 shown in FIG. 7 including a closed circular tank 40, a compressor 41, a controller 42, etc., the tank 40 was thoroughly degassed and DO (Dissolved Oxygen) was used. ) From the top of the tank 40 while supplying still water with a constant value.
The atmospheric pressure (kgf / cm ² ) of 5 atm was supplied, and the dissolved oxygen amount (DO value) of the still water taken out from the water intake port 44 at the bottom of the tank 40 was measured every predetermined time using a DO meter.

Experiments were conducted in the case where the interface between the static water and the compressed air in the tank, that is, the surface of the water was not directly contacted with the compressed air and the static water, and as a separation membrane, liquid paraffin, EVO
This was carried out for the case where H and silicon were each floated. The experimental results are shown in FIGS.

From the experimental results, it was found that the amount of dissolved oxygen increases with time without a separation membrane, and tends to increase even after the experimental measurement time (30 minutes). Further, when a separation membrane is provided, the amount of dissolved oxygen decreases in both cases, but when liquid paraffin is used as the separation membrane, the membrane becomes uneven during pressurization, and oxygen is dissolved in water from that portion, D
Regarding the O value, the result did not show a large difference from the case without the separation membrane. It has been found that when EVOH or silicon is used as the separation membrane, air is hardly passed from the beginning of pressurization, and the effect of inhibiting oxygen dissolution in water is great.

[Experimental Example 2] As shown in FIG.
The AES tank 50 was provided, and the DO meter 52 was installed in the pressurized water 51 at the bottom of the tank to investigate the dissolved oxygen amount. When the dissolution prevention structure is not provided,
The respective experimental results when the dissolution preventing structure made of silicon is provided are shown in FIGS.

From the experimental results, in the case where the dissolved prevention structure is not provided, when pressurized air is fed into the tank 50 to lower the water level, the dissolved oxygen amount, that is, the DO value rapidly increases, but it is made of silicon. When a dissolution prevention structure is provided,
It was found that even if the water level in the tank 50 is lowered, the DO value hardly changes, so that the dissolution of compressed air is effectively prevented.

[0036]

As described above, according to the structure for preventing the stored compressed air from dissolving in the compressed air storage tank, the curtain structure is installed to cover the pressurized water surface in the tank without adopting the conventional push head system. Dissolution of the stored compressed air into the pressurized water can be easily prevented with a simple structure.

Silicone oil and EVOH are used as the curtain structure.
By using a synthetic resin curtain or the like containing, it is possible to effectively block the boundary between the compressed air stored in the tank and the pressurized water, despite the simple structure of floating them on the water surface. .

Further, in the case where the compressed air storage tank is a tunnel type compressed air tank extending in the lateral direction, the curtain structure is provided by fixing the periphery to the wall surface of the tunnel so as to divide the cavity of the tunnel up and down. Further, by constituting the elastic curtain capable of swelling up and down, it is possible to stably cover a wide range of water surface by following the vertical movement of the water surface.

According to the method for installing the dissolution preventing structure of the present invention, a synthetic resin screen containing silicon oil and EVOH,
The curtain structure made of liquid paraffin or the like for covering the water surface in the underground tank can be easily installed in a floating manner only by the work from the ground without the worker entering the underground tank.

[Brief description of drawings]

1A and 1B are cross-sectional views showing an embodiment of a dissolution preventing structure of the present invention.

FIG. 2 is a partially cutaway plan view taken along the line AA of FIG.

3 (a) to 3 (f) are process drawings showing an embodiment of a method for installing a dissolution preventing structure according to the present invention.

4 (a) and 4 (b) are explanatory views showing a step of further taking out the dissolved prevention structure from the tank in the installation method shown in FIG.

FIG. 5 is a sectional view showing another embodiment in which the dissolution preventing structure of the present invention is adopted in a tunnel-type underground tank.

6A to 6C are explanatory views showing a situation in which the elastic film swells up and down as the compressed air is stored and taken out in the dissolution preventing structure shown in FIG.

7 is an explanatory diagram showing a configuration of an apparatus used in Experimental Example 1. FIG.

8A to 8C are charts showing experimental results according to Experimental Example 1.

FIG. 9 is an explanatory diagram showing an implementation status of Experimental Example 2;

FIG. 10 is a chart showing experimental results according to Experimental Example 2,
(A) shows the experimental results when the dissolution preventing structure is not provided, and (B) shows the experimental results when the dissolution preventing structure made of silicon is provided.

FIG. 11 is an explanatory view showing a dissolution preventing means by a conventional push-in head method.

[Explanation of symbols]

 10,30 Dissolution prevention structure 11,31 Underground storage tank 12,33 Air supply pipe 13,34 Water supply pipe 14 Storage space 15 Membrane structure 16 Silicon liquid film 17 Synthetic resin film 18 Ever film 25 Confined water 32 Rock tunnel 36 Elastic film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 391058657 Tone Underground Technology Co., Ltd. 2-16-2 Minami Kamata, Ota-ku, Tokyo (71) Applicant 000000549 Obayashi Corporation 4-33 Kitahama East, Chuo-ku, Osaka-shi, Osaka No. (72) Inventor Shigeo Honma 380 Minamikaneme, Hiratsuka City, Kanagawa Prefecture Tokai University No. 3 Residential Housing No. 202 (72) Inventor Masao Hayashi 131-7 Wakamatsu, Abiko City, Chiba Prefecture Kugenuma Matsugaoka 2-16-2

Claims (6)

[Claims] 1. A storage pressure air used in a storage tank of a water pressure compensating system for storing pressure air while compensating the pressure for storage by the pressure water sent into the tank, wherein the stored pressure air is dissolved in the pressure water. Dissolution of stored compressed air in a compressed air storage tank, characterized by comprising a curtain structure for covering the pressurized water surface in the tank to block contact with the stored compressed air for preventing Prevention structure. 2. The dissolved pressure preventing structure for stored compressed air in a compressed air storage tank according to claim 1, wherein the curtain structure is composed of a liquid curtain of silicon floating on the surface of the pressurized water. 3. The stored compressed air in the compressed air storage tank according to claim 1, wherein the curtain structure is made of a synthetic resin curtain containing an ethylene vinyl alcohol copolymer floating on the surface of the water to be compressed. Dissolution prevention structure. 4. The curtain structure comprises a composite curtain that floats on the surface of the water under pressure and is laminated with a liquid curtain of silicon and a synthetic resin curtain containing an ethylene vinyl alcohol copolymer. 1. A structure for preventing stored compressed air from being dissolved in the compressed air storage tank according to 1. 5. The water pressure compensation tank is a laterally extending tunnel type compressed air tank, and the curtain structure secures the periphery to the wall surface of the tunnel so as to vertically divide the cavity of the tunnel. The structure for preventing the stored compressed air from being dissolved in the compressed air storage tank according to claim 1, characterized in that the structure comprises an elastic curtain that is swellable up and down. 6. A method of installing a dissolved prevention structure for installing the dissolved compressed air storage structure according to any one of claims 1 to 4 in a compressed air storage tank, the compressed air storage tank The inside of the water supply pipe and the air supply pipe provided to connect the tank with the ground is filled with water, and a fixed amount of water is pumped through the water supply pipe to store the water supply pipe and the storage. The filling water in the air supply pipe communicating through the tank for water is reduced, the membrane member constituting the membrane structure is inserted into the upper portion of the air supply pipe where the filling water is lowered, and thereafter, the upper portion of the air supply pipe is hermetically sealed. By supplying compressed air into the air supply pipe, the compressed air pushes down the membrane member toward the inside of the tank together with filling water, and the membrane member has a membrane structure that covers the pressure-compensated water for pressure compensation in the tank. Tank for compressed air storage characterized by being installed A method for installing a structure for preventing the dissolution of stored compressed air in the environment.