JP2001280594A - Storage facility in bedrock, method of execution of work and leakage detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety by surely implementing detection of a leakage from a hermetic material for stored gas. SOLUTION: In a storage facility, a bedrock a gas leakage detection space 4 composed of an insulation material 5 and a hermetical keeping plate 6 is formed at the outside part of a hermetical material. The space 4 is arranged vertically and horizontally along a hermetic member welding part 21 and is connected to a plurality of collection pipes 17 connected to a gas detector 18, as well as a gas collecting chamber 19 at a ground part 11 at a top part of a facility 1. Before storing natural gas 10, a detection liquid for ammonia gas leak test is applied to the hermetical material welding part 21 from the inside of the hermetical material 3. At a bottom of the facility 1, a gas inlet tube 27 is layed, and ammonia gas is filled in the space 4. When ammonia gas leaks from the hermatic material 3, the color of the detection liquid applied to the hermetical material welding part 21 changes from yellow to blue, to thereby specify a leakage part of the hermetic material welding part 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-rock storage facility for storing high-pressure gas in a rock, a construction method thereof, and a method of inspecting a hermetic material for leakage.

[0002]

2. Description of the Related Art Conventionally, in a storage facility in a rock where high-pressure gas such as natural gas is stored, it has been studied to maintain airtightness by an airtight material (container).

If the stored high-pressure gas leaks to the backfill concrete side, it is conceivable that the high-pressure gas is collected by an air leak collecting pipe. FIG. 6 is a partial sectional view of such a storage facility 101 in rock. As shown in FIG. 6, a blown concrete 108 is sprayed on the wall surface of the rock mass 109 formed by excavation in order to smooth out unevenness due to excavation. Inside the sprayed concrete 108, a backing concrete 107 having a reinforcing steel bar or a flat steel bar is constructed. Leakage collecting tube 106 for collecting leaked gas in backfill concrete 107
Is provided. An insulating material 105 and an airtight material 103 are provided inside the backfill concrete 107.

[0004]

However, in the storage facility 101 in the bedrock, when a penetration defect such as a crack occurs in the hermetic material 103 for some reason, and the stored high-pressure gas leaks to the backfill concrete 107 side. The air is collected by the air leak collecting tube 106, but 100% collection is not always reliable. In addition, there is a possibility that a small amount of leakage cannot be detected.

[0005] Further, since a large number of hermetic members 103 are welded, there is a demand for inspecting leakage of a welded portion.

The present invention has been made in view of such a problem, and an object of the present invention is to securely detect a leak of a stored gas from an airtight material, and to provide a highly safe storage facility in a rock. An object of the present invention is to provide a construction method and a leakage inspection method.

[0007]

According to a first aspect of the present invention, there is provided a rock storage facility provided in a cavity formed in a rock, wherein the container body of the rock storage facility is provided. A storage facility in rock mass, which has a leak detection space in itself.

[0008] A second invention is a storage facility in a rock mass provided in a cavity formed in the rock mass, wherein the wall surface is composed of an airtight material and an insulating material provided outside the airtight material. A backfill storage facility, wherein backfill concrete is provided between the wall surface and the cavity, and a leak detection space is provided in the insulating material.

A third aspect of the present invention is a method for constructing a storage facility in a rock mass provided in a cavity formed in a rock mass, comprising a hermetic material and an insulating material provided outside the hermetic material. A method for constructing a storage facility in a rock mass, characterized in that a wall surface to be provided is provided, a leak detection space is provided in the insulating material, and backfill concrete is provided between the insulating material and the cavity. .

In a fourth aspect of the present invention, there is provided a method for inspecting leakage of a storage facility in a bedrock according to claim 2, wherein a detection liquid is applied to the inside of the airtight material, and the leak detection space is filled with ammonia gas. When the ammonia gas leaks from the hermetic material, the detection liquid is discolored and the leakage is inspected.

According to a fifth aspect of the present invention, there is provided a method for inspecting leakage of a storage facility in a rock mass according to claim 2, wherein when gas is stored inside the storage facility in a rock mass, the ground is detected via the leak detection space. This is a method for inspecting a leak in a storage facility in a rock mass, which detects a gas leaking to a part.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a storage facility 1 in a rock mass and surrounding facilities according to the present embodiment.
FIG. 2 is a sectional perspective view showing a schematic configuration of the storage facility 1 in the rock. The in-bed storage facility 1 is a facility for storing a gas such as natural gas at high pressure in a bed.

[0013] As shown in FIG.
A cavity 2 in the bedrock is excavated and formed in the bedrock 9, an airtight material (container body) 3 made of thin steel is provided in the cavity 2 in the bedrock, an insulating material 5 is provided around the airtight material 3, and This is a structure in which backfill concrete 7 is provided therebetween.

For excavating the cavity 2 in the bedrock,
An access tunnel 13 is provided between the storage facility 1 in the bedrock and the plug 12 is provided between the tip of the access tunnel 13 and the storage facility 1 in the bedrock. A compressor 15 for compressing a stored gas such as natural gas is provided in the above-ground unit 11.
The compressor 15 is connected to the storage facility 1 in bedrock through a pipe 14. The compressor 15 is provided with a city gas conduit 16 through which a stored gas such as natural gas flows.

At the top of the storage facility 1 in the bedrock, an air collecting pipe 17 is provided.
Is provided, and a gas collecting chamber 19 is provided on the ground portion 11. The storage facility 1 in the bedrock and the gas collecting chamber 19 are connected via an air collecting pipe 17. In addition, the air collecting pipe 17 above the ground
A gas detector 18 for detecting a leaked gas used for a leak inspection of the airtight material 3 is provided at a tip of the gas sensor 18.

As shown in FIG. 2, the storage facility 1 in the bedrock is of a so-called silo type having a cylindrical lower part and a hemispherical upper part. In the storage facility 1 in rock, natural gas 1
Store high pressure gas such as 0. The maximum working pressure of the natural gas 10 stored in the rock storage facility 1 is, for example, 70
Atmospheric pressure to about 250 atm. In addition, storage facility 1 in bedrock
May have another shape such as a tunnel type.

Next, the structure and construction method of the storage facility 1 in rock will be described in detail. Fig. 3 shows the storage facility 1
FIG. FIG. 4 is a partial sectional view of the storage facility 1 in the rock. As shown in FIGS. 3 and 4, the inside of the bedrock 9 is excavated to construct the cavity 2 in the bedrock. Then, sprayed concrete 8 is provided as a support on the wall surface of the excavated rock mass 9.

A mold or the like is provided inside the sprayed concrete 8 inside the position of the airtight material 3 to provide the airtight material 3. The material of the airtight material 3 is a thin steel plate that maintains airtightness. An insulating material 5 is provided outside the airtight material 3. The insulating material 5 is a deformable and flexible material that prevents the propagation of a shear force that may cause distortion in the airtight material 3. The insulating material 5 is made of a material such as polyethylene and Teflon (registered trademark).

The insulating material 5 placed outside the hermetic material 3 is determined by analysis and experiment at a position that is not affected by heat during welding of the hermetic material 3, and is transported to the site in a state where it is temporarily fixed at the back of the hermetic material 3 at a factory. I do.

The airtight material 3 and the insulating material 5 are in the form of a thin plate, and a space is provided between adjacent insulating materials 5.
As shown in FIG. 4, the airtight material 3 is obtained by welding a large number of thin steel plates. That is, the hermetic material 3 is welded on-site at the hermetic material welding portion 21.

The airtight material 3 is used as a formwork instead of the backfill concrete 7 between the sprayed concrete 8 and the insulating material 5.
Is provided. The backfill concrete 7 is a reinforcing steel or a plain concrete. On the outside of the airtight material 3, an airtight material weld 21
A gas leak detection space 4 is provided along the line.

That is, as described above, a space is provided between adjacent insulating members 5, and an airtight holding plate 6 is provided behind this space. The airtight holding plate 6 secures airtightness, and the material of the airtight holding plate 6 is a steel plate similar to the airtight material 3 or a polyethylene sheet having no permeability.
Therefore, the gas leak detection space 4 is formed by the hermetic material welding portion 21, the insulating material 5, and the hermetic holding plate 6.

The gas leak detection space 4 is used for a leak inspection of the airtight material 3. When the internal pressure due to the stored gas is applied to the surface of the airtight material 3, the airtight material 3 is bent in the direction of the gas leak detection space 4, so that a bending stress is generated in the airtight material 3. Keep it.

After the sprayed concrete 8 has been applied, a formwork or the like may be provided at the position of the insulating material 5, and the backfill concrete 7, the insulating material 5, and the airtight material 3 may be provided.

FIG. 5 is a view showing the arrangement of the airtight material 3.
As shown in FIG. 5, the gas leak detection space 4 is arranged vertically and horizontally along the airtight material welded portion 21, and is connected to the gas collecting chamber 19 of the ground portion 11 at the top of the storage facility 1 in the rock. Connected to a plurality of air collection tubes 17. As described above, in the storage facility 1 in the rock, the gas leak detection space 4 including the insulating material 5 and the airtight holding plate 6 is formed outside the airtight material 3.

In the storage facility 1 in the bedrock, after the storage facility 1 in the bedrock is completed and before the natural gas 10 is stored, the gas leak detection space 4 is used as an ammonia gas passage for an ammonia leak test, and A leak test of the airtight material 3 is performed by a leak test.

Next, a detailed description will be given of a leak inspection method by an ammonia leak test of the airtight material 3 using the gas leak detection space 4 as an ammonia gas passage for an ammonia leak test.

Before the natural gas 10 is stored in the storage facility 1 in the bedrock shown in FIG. 4 and FIG.
A detection liquid for an ammonia leak test is applied from the inside of the airtight material 3. Next, a gas introduction tube 27 is arranged at the bottom of the storage facility 1 in the rock, and ammonia gas is inserted into the gas leak detection space 4. When the ammonia gas leaks from the hermetic seal 3, the detection liquid applied to the hermetic seal weld 21 changes its color from yellow to blue, and specifies the leak location of the hermetic seal weld 21. Such a leak detection method using ammonia gas is described in L
This method is already used in NG underground tanks and the like.

In this case, by blocking the passage of the gas leak detection space 4, the ammonia gas is conducted only in the block 23-2.
The leakage inspection of only 3-2 may be performed. Then, similarly, a leak inspection of another block 23-1 is performed. Also, leakage detection is performed on the bottom surface.

As described above, the storage facility 1 in the bedrock is provided with the airtight material 3
A gas leak detection space 4 composed of an insulating material 5 and an airtightness retaining plate 6 is provided outside of the space, and before storing the natural gas 10, the gas leak detection space 4 is used as an ammonia gas passage for an ammonia leak test. Using this, an ammonia leak test, which is a leak test of the airtight material 3, can be performed.

In the storage facility 1 in the bedrock, if there is a leak from the airtight material 3 after the actual operation, that is, while the natural gas 10 is being stored, the gas leak detecting space 4 is connected to the ground via the collecting pipe 17. By detecting the natural gas 10 as the stored gas by the gas detector 18 of the section, it is possible to detect the leak of the natural gas from the airtight material 3.

Next, a leakage inspection method for detecting leakage of the natural gas 10 from the airtight material 3 will be described in detail. FIG.
As shown in the figure, a plurality of gas leak detection spaces 4 are arranged vertically and horizontally along the hermetic material welded portion 21 and connected to the gas collecting chamber 19 at the top of the rock storage facility 1 at the top. It is connected to the air collecting pipe 17. Further, as shown in FIG. 1, a gas detector 18 for detecting a stored gas is provided at a tip of an air collecting pipe 17 on the ground.

When natural gas 10 is stored, nitrogen gas is inserted into gas leak detection space 4 from gas introduction tube 27 at the bottom of storage facility 1 in storage rock, and gas leak detection space 4 is filled with nitrogen gas. It is. Gas leak detection space 4
Can be divided into a plurality of blocks 23-1, 23-2,.... The air collecting pipe 17 is connected to each block 23, and the gas detector 18 is provided.

If the natural gas 10 leaks into the gas leak detection space 4 from the hermetic material welding portion 21 or the like during storage of the natural gas 10, the nitrogen gas pressure in the gas leak detection space 4 is much higher than the stored gas pressure. Since it is low, the natural gas 10 rises through the air collecting pipe 17, and the gas is detected by the gas detector 18. Thus, it can be seen that the gas leaks at the block 23 corresponding to a certain gas detector 18.

As described above, the insulating material 5 is provided outside the airtight material 3.
And a gas leak detection space 4 comprising a gas tightness holding plate 6 and, during storage of natural gas 10, divide the gas leak detection space 4 into a plurality of blocks 23-1, 23-2,. By detecting the natural gas 10 with the above-mentioned gas detector 18 connected from the space 4 via the air collecting pipe 17, a leak can be detected, and safety is further improved.

[0036]

As described above in detail, according to the present invention, it is possible to reliably detect leakage of a stored gas from an airtight material, and to provide a highly safe storage facility in a rock, its construction method, and a leakage inspection method. Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rock storage facility 1 and surrounding facilities according to the present embodiment.

FIG. 2 is a cross-sectional perspective view showing a schematic configuration of a storage facility 1 in bedrock.

FIG. 3 is a cross-sectional view of the storage facility 1 in bedrock.

FIG. 4 is a partial sectional view of the storage facility 1 in the bedrock.

FIG. 5 is a view showing the arrangement of the airtight material 3;

FIG. 6 is a partial cross-sectional view of a conventional storage facility 101 in bedrock.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Storage facility in rock 2 ... Cavity in rock 3 ... Sealing material (container body) 4 ... Space for gas leak detection 5 ... Insulating material 6 ... Sealing plate 7 ... … Backfill concrete 8… sprayed concrete 9… rock bed 10… natural gas 11… above ground 13… access tunnel 14… pipes 15… compressor 16… city gas Conduit 17 Air collecting pipe 18 Gas detector 19 Gas collecting chamber 21 Airtight material welded part 23 Block

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hajime Okino 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. F term (reference) 2D047 AB02 2D055 AA10 3E072 AA10 GA30

Claims (14)

[Claims] 1. A storage facility in a rock which is provided in a cavity formed in the rock, wherein a leak detection space is provided in a container itself of the storage facility in the rock. 2. A storage facility in a rock mass provided in a cavity formed in a rock mass, wherein the wall surface is composed of an airtight material and an insulating material provided outside the airtight material, wherein the wall surface and the cavity are provided. A backfilling concrete is provided between the storage material and a space for leakage detection is provided in the insulating material. 3. The storage facility according to claim 2, wherein the airtight material is welded, and the leak detection space is provided along a welded portion. 4. The storage facility according to claim 2, wherein an airtight holding plate is provided at a portion of the backfill concrete in contact with the leak detection space. 5. The storage facility according to claim 2, wherein the leak detection space is connected to an air collecting pipe leading to a ground portion. 6. The storage facility in a bedrock according to claim 4, wherein the airtightness maintaining plate has high rigidity and does not have permeability. 7. The storage facility in a rock mass according to claim 4, wherein said airtight holding plate is made of steel or a polyethylene sheet. 8. The storage facility according to claim 2, wherein the airtight material is made of thin steel. 9. A method for constructing a storage facility in a rock mass provided in a cavity formed in a rock mass, comprising: providing a wall surface comprising an airtight material and an insulating material provided outside the airtight material; A space for leak detection is provided in the insulating material, and a backfill concrete is provided between the insulating material and the cavity. 10. The leak inspection method for a storage facility in a bedrock according to claim 2, wherein a detection liquid is applied to the inside of the hermetic material, the leak detection space is filled with ammonia gas, and the ammonia gas is filled with the hermetic material. A leak detection method for a storage facility in a bedrock, wherein the detection liquid is discolored when leaked from the tank. 11. The leak inspection method for a storage facility in a rock mass according to claim 2, wherein when gas is stored inside the storage facility in a rock mass, the gas leaking to the ground portion through the leak detection space. A leak inspection method for a storage facility in a rock mass, characterized by detecting. 12. The leakage inspection according to claim 10, wherein a leakage detection space is blocked and leakage inspection is performed.
1. The method for leak inspection of a storage facility in rock according to 1. 13. The method according to claim 11, wherein a low-pressure gas is inserted in the leak detection space in advance. 14. The method according to claim 13, wherein the low-pressure gas is nitrogen gas.