KR20130000164A

KR20130000164A - High-pressure fluid reservoir having plug improved in air tightness

Info

Publication number: KR20130000164A
Application number: KR1020110060697A
Authority: KR
Inventors: 류동우; 김형목; 박도현; 최병희; 송원경
Original assignee: 한국지질자원연구원
Priority date: 2011-06-22
Filing date: 2011-06-22
Publication date: 2013-01-02

Abstract

The present invention relates to a high pressure fluid reservoir for storing compressed air in a CAES system. The fluid reservoir according to the present invention is a cavern formed by excavating a rock at an underground core in a form in which one end of the high pressure fluid is stored, and to close the open end of the cavern to seal the cavern. It is provided with a plug having a contact surface is formed in contact with the underground rock when pressed by the fluid stored in the,
One end of the cavern is installed with the plug inserted, so that the outer surface of the plug is in close contact with the rock by pressurization of the fluid, or a recess is formed at the end of the plug so as to communicate with the cavern, and the plug is pressurized by the fluid. It is characterized by the outer surface of the close contact with the rock.

Description

High-pressure fluid reservoir having plug improved in air tightness

The present invention relates to a fluid storage tank for storing a high pressure fluid, and more particularly to a high pressure fluid storage tank for storing high pressure compressed air in a CAES (Compressed Air Energy Storage).

In order to revitalize the development of renewable energy and nuclear energy, which have recently been gaining attention, it is necessary to develop a means of storing surplus power and a rapid peak load response method. As one of the methods, domestic and foreign interest in the CAES-G / T (Compressed Air Energy Storage Gas Turbine System) technology, which stores compressed air with surplus power and uses it for power generation of gas turbines, is increasing.

Recently, in the United States, CAES-type power generation has attracted great attention as a strong candidate for buffer facilities that store surplus power generated in large-scale wind farms, and domestic industry has already shown interest in CAES power generation.

Currently operating CAES-based power plants include the Huntorf power plant in Germany and the McIntosh power plant in the United States, which utilize caves made by melting rock salt as compressed air storage. However, if a CAES-type power plant is constructed in Korea where there is no rock salt layer, the compressed air is likely to be stored in underground rock tunnels due to the topography. Although there is no experience in the construction of rock tunnel CAES power plants worldwide, interest in rock tunnel compressed air storage facilities has been maintained.

When storing compressed air in rock tunnels, it is essential to install concrete plugs to isolate the compressed air storage section from the outside. Since a high pressure of 5 MPa or more operates inside the CAES tunnel, designing a concrete plug that is stable against internal air pressure and acupressure is expected to be a key part of the CAES tunnel design technology.

One of the important factors in the concrete plug is the sealing of the plug. When the plug is installed in the CAES tunnel, the plug is pressurized to the outside by high-pressure compressed air. After a certain time, the plug's sealability is deteriorated due to a problem such as a gap between the plug and the rock or an extension of the crack. May occur.

Therefore, it is very important to secure the design technology of the sealed concrete plugs for the smooth implementation of the national energy development plan.

An object of the present invention is to provide a high pressure fluid storage tank having improved sealing performance by improving the structure of a plug in a fluid storage tank for storing a high pressure fluid such as compressed air.

The high pressure fluid reservoir according to the present invention for achieving the above object is a cavern formed in the rock of the underground core in the form where one end is opened as the high pressure fluid is stored, and by closing the open end of the cavern The plug is for sealing the cavern, and has a plug having a contact surface formed by contact with an underground rock when pressurized by a fluid stored in the cavern, and having one end of the cavern inserted into the plug. The outer surface of the plug is in close contact with the rock by the pressurization of the fluid.

In addition, the fluid storage tank according to the present invention for achieving the above object is a cavern formed in the rock of the underground core in the form where one end is opened as a high-pressure fluid is stored, and closes the open end of the cavern The plug is for sealing the cavern and has a plug having a contact surface which is engaged with the underground rock when it is pressurized by the fluid stored in the cavern, and an end of the plug is formed with a recess to communicate with the cavern. The outer surface of the plug is in close contact with the rock by pressure of the fluid.

According to the present invention, the plug includes a tapered portion whose diameter gradually decreases in a direction away from the cavern, and an outer surface of the tapered portion forms the contact surface.

In another embodiment, the plug is a wedge type having an enlarged portion that gradually increases in diameter along a direction away from the cavern, and a reduced portion that gradually decreases in diameter from an end portion of the expanded portion, and an outer surface of the reduced portion may contact the contact surface. Form.

In another embodiment, the plug is formed in a cylindrical shape.

The plug is formed with a hole penetrating between one side and the other side, and the hole is open and closeable.

In the present invention, the cavern may be formed in a tunnel shape or a silo shape.

In the present invention, the cavern is installed to be inserted into the plug, or the plug is installed on the outside of the cavern while forming a groove communicating with the cavern in the plug to substantially act to insert the cavern into the plug, so that the compressed air is pressurized by the plug. The outer surface of the shell is to be in close contact with the rock, shear force is generated between the plug and the rock has the advantage of improving the airtightness and stability of the plug.

1 is a schematic cross-sectional view of a fluid reservoir according to a first embodiment of the present invention, having a wedge-shaped plug.
Figure 2 is a schematic cross-sectional view of a fluid reservoir according to a second embodiment of the present invention, having a tapered plug.
Figure 3 is a schematic cross-sectional view of a fluid reservoir according to a third embodiment of the present invention, having a block plug.
4 is a schematic cross-sectional view of a modification of the fluid reservoir according to the first embodiment shown in FIG.
5 is a schematic cross-sectional view of a modification of the fluid reservoir according to the second embodiment shown in FIG.
6 is a schematic cross-sectional view of a modification of the fluid storage tank according to the third embodiment shown in FIG.
FIG. 7 is a schematic cross-sectional view of another modification of the fluid storage tank according to the first embodiment shown in FIG. 1.
8 is a schematic cross-sectional view of another modification of the fluid reservoir according to the second embodiment shown in FIG.
9 is a schematic cross-sectional view of another modification of the fluid storage tank according to the third embodiment shown in FIG.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail with respect to the high pressure fluid reservoir according to an embodiment of the present invention.

1 is a schematic cross-sectional view of a fluid reservoir according to a first embodiment of the present invention.

Referring to FIG. 1, the fluid reservoir 100 according to the first embodiment of the present invention includes a cavern 10, a lining 20, and a plug 30.

Cavern 10 is a cavity for storing high pressure fluid and is formed in the basement deep. Fluid stored in the cavern 10, in this embodiment the compressed air of the CAES system, is typically stored at a high pressure of at least 5 MPa or more. In order to store such high pressure fluids, it is desirable to form caverns in the depths of several hundred meters underground. Since there is no rock salt layer in domestic geological conditions, Cavern 10 is mainly formed by excavating underground rock (g).

In the first embodiment, the shape of the cavern 10 is tunnel-shaped and is disposed long along the horizontal direction. The length of the tunnel varies depending on the scale, but can form the cavern 10 on the scale of tens of meters to hundreds of meters.

The compressed air from the ground compressor is stored at high pressure in the cavern 10 through a connecting line (not shown), and when generation is required, the compressed air of the cavern 10 is sent to the ground through the connecting line to operate the turbine. Let's do it.

When the cavern 10 is formed by blasting and excavation, the lining 20 is installed. The lining 20 serves to seal the compressed air in the cavern 10 to prevent leakage of the compressed air through the crack of the rock g and to transfer the pressure of the compressed air to the surrounding rock.

The construction of the lining 20 can vary, in this embodiment consisting of a steel liner 21 and a backfill concrete 22. In another embodiment, without using a steel liner as a lining, butyl rubber may be attached to the reinforced concrete and other types of lining may be used.

When the cavern 10 is formed by excavation, the excavation surface is stabilized using shotcrete (not shown), and the steel liner 21 is constructed in a state spaced apart from the surface on which the shockcrete is placed. The lining 20 is completed by filling and curing the backfill concrete 22 between the steel liner 21 and the excavation surface.

The sealing property is ensured by the steel liner 21 in the structure of the lining 20 as described above, the backfill concrete 22 serves to transmit the pressure of the compressed air in the cavern 10 to the surrounding rock.

The plug 30 is for finally closing off the open end of the cavern 10 formed by excavation. Plug 30 is installed at the end of the cavern 10 to seal the opening, the important point is to ensure stability and airtightness, in the present invention to change the installation position and structure of the plug to ensure the stability and airtightness of the plug Is the main purpose.

The plug 30 employed in the first embodiment is a wedge-shaped plug. That is, the expansion part 31 which gradually increases in diameter along the direction away from the cavern 10, and the reduction part 32 which gradually decreases in diameter from the expansion part 31 are provided.

When the compressed air is filled in the cavern 10, the plug 30 is forced outward by the pressure of the compressed air, and the outer surface 32a of the reduced portion 32 of the plug 30 contacts the rock g. Forming a contact surface, the plug 30 is a structure that withstands the pressure of the compressed air is caught on the rock.

The wedge-shaped plug of the above structure has been previously installed on the outer side of the cavern 10, and as the plug continues to be pressed outwards, a crack is generated between the outer surface 31a of the expansion part 31 and the rock (g). There was a problem that the compressed air flows out through a gap formed between the plug or the rock and the crack formed in the existing rock.

In the present invention, to solve this problem, the outer surface of the plug 30 is to be a structure that can be in close contact with the excavation surface of the rock (g).

Referring to FIG. 1, in the present invention, the plug 30 is not installed outside the cavern 10 as in the related art, and an end of the plug 30 is installed in a form surrounding the one end of the cavern 10. In other words, one end of the cavern 10 is installed while being inserted into the plug 30.

When the end of the cavern 10 is installed with the plug 30 inserted, as shown by the arrow in FIG. 1, the pressure of the compressed air acts in the longitudinal direction of the cavern 10 so that the plug 30 is moved outward. It also pushes out, but also acts in the radial direction of the cavern 10 to press the outer surface 31a of the plug 30 toward the rock g. That is, the plug 30 is pressed and the outer surface 31a comes into close contact with the rock g.

When the outer surface 31a of the plug 30 is in close contact with the rock g, the sealing property is improved by itself, and the shear force is generated between the rock g and the plug 30 to improve the stability and airtightness of the plug. There is.

That is, by installing one end of the cavern 10 in the inserted state in the plug 30, the plug 30 is in close contact with the rock (g), the shear force is generated between the rock and the plug 30, the plug ( 30) stability and airtightness are improved together.

2 and 3 show a second embodiment and a third embodiment employing plugs different from the above-described first embodiment, respectively. 2 and 3, the cavern 10 and the lining 20 have the same configuration as those of the first embodiment, and therefore, the same reference numerals are given, and description thereof will be omitted.

Referring to FIG. 2, in the second embodiment 200, a tapered plug 40 is employed. The tapered plug 40 has a smaller diameter as it moves away from the cavern 10 to form an inclined shape.

The outer surface 41 of the plug 40 forms a contact surface in contact with the rock g, and the outer surface 41 is caught by the rock g when the compressed air in the cavern 10 is pressed to withstand the pressure.

And, referring to Figure 3, the plug 50 employed in the third embodiment 300 is formed in a block shape. That is, it is made of a cylindrical or hexahedral shape having a constant diameter regardless of the distance from the cavern 10.

In the block-type plug 50, the outer surface 51 and one side 52 are in contact with the rock, and in particular, the one side 52 is hooked on the rock to withstand the pressure of the compressed air.

Similarly in the third embodiment, the cavern 10 is inserted into the plug 50 so that the compressed air presses the plug 50 both in the longitudinal direction and in the radial direction of the cavern 10. The radially pressurized plug 50 has an effect that the outer surface 51 and the rock g are in close contact, and the shear force is generated to improve the stability and airtightness of the plug 50.

As described above, in the first to third embodiments, regardless of the specific shape of the plug, one end of the cavern 10 is inserted into the plugs 30, 40, and 50 so that the plugs 30, 40, By pressing 50) radially, the airtightness and stability of the plug are improved.

Reference numerals 33, 43, and 53, which are not described in the drawings of FIGS. 1 to 3, are holes for maintenance of the tunnel and the plug, and are formed through one side and the other side of the plug. It remains closed except for that.

In addition, in the drawings of FIGS. 1 to 3, the steel liner is formed to the inner surface of the plug to increase the sealing property. Here, an airtight material such as butyl rubber may be used instead of the steel liner.

In addition, although not shown in the drawings of FIGS. 1 to 3, a connection line connected to a CAES facility on the ground such as a compressor turbine is installed, which may be installed through a plug, or may be separately installed.

4 to 6 show modified examples of the first to third embodiments, respectively.

In the modified example of FIGS. 4 to 6, all components are the same as those of the first to third embodiments, and only the shape of the plug is changed. Therefore, descriptions of elements denoted by the same reference numerals will be omitted.

In the embodiment 100 illustrated in FIG. 1, the cavern 10 was inserted into the plug 30. However, in the variation 100 ′ of the first embodiment illustrated in FIG. 4, the cavern 10 is connected to the plug 30. Although not inserted into the '), the groove portion 39 is formed concave in the plug 30' to form a form in which the cavern 10 extends.

That is, since the cavern 10 and the groove 39 are in communication with each other, the compressed air is filled together with the cavern 10 and the groove 39, and the compressed air of the groove 39 radially pulls the plug 30 '. The outer surface 31 is pressed against the rock g to produce the same effect as that of the first embodiment.

The plug 40 'employed in the modification 200' of the second embodiment shown in Figs. 5 and 6 and the plug 50 'employed in the modification 300' of the third embodiment are also the second embodiment. Unlike the third embodiment, the cavern 10 is not inserted into the plugs 40 'and 50', but instead, the grooves 49 and 59 are formed to be concave in the plugs 40 'and 50'. The cavern 10 is extended, and the airtightness and stability are improved by bringing the outer surfaces of the plugs 40 'and 50' into close contact with the rock as in the previous embodiments.

On the other hand, Figs. 7 to 9 show yet another half type examples 100 '', 200 '', 300 '' of the first to third embodiments.

In FIGS. 7 to 9, the cavern 10 has a silo shape instead of a tunnel type. The silo shape may be formed in a cylindrical shape in a vertical direction, and may be selectively formed in a dome shape on the upper end and the lower end.

The tunnel type cavern of FIGS. 1 to 6 has an advantage that it is suitable for a large capacity, and the silo type cavern is difficult to form as compared to the tunnel form, but it is less than the tunnel type in terms of capacity, but it is structurally more stable than the tunnel form. have.

7 to 9 have the same structure as the plugs 30 ', 40', and 50 'employed in the embodiments shown in FIGS. That is, grooves 39, 49, and 59 are formed in the plugs 30 ', 40', and 50 ', respectively, so as to communicate with the cavern 10. Therefore, the compressed air of the grooves 39, 49 and 59 presses in the direction in which the outer surfaces of the plugs 30 ', 40' and 50 'are in close contact with the rock, thereby bringing the rock and the plug into close contact and generating shear force, Improve airtightness and stability.

In addition, reference numeral s not described in FIGS. 4 to 9 may be a panel made of steel or butyl rubber as an airtight material attached to the inner surface of the plug groove.

As described above, in the present invention, the cavern is installed to be inserted into the plug as in the first to third embodiments, or as in the modified embodiment shown in FIGS. 4 to 9, the plug is installed outside the cavern. In addition, by forming a groove communicating with the cavern in the plug, the cavern is substantially inserted into the plug, thereby improving the airtightness and stability of the plug.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation and that those skilled in the art will recognize that various modifications and equivalent arrangements may be made therein. It will be possible. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

100 (100 ', 100'') ... high pressure fluid reservoir according to the first embodiment and the modification
200 (200 ', 200'') ... high pressure fluid reservoir according to the second embodiment and the modification
300 (300 ', 300'') ... high pressure fluid reservoir according to the third embodiment and the modification
10 ... Cavan 20 ... Lining
21 ... Steel Liner 22 ... Backfill Concrete
30 (30 ') ... wedge plug, 40 (40') ... tapered plug
50 (50 ') ... block plug 39, 49, 59 ... groove

Claims

Where the high-pressure fluid is stored, the cavern formed by excavating the rock in the underground core in an open shape at one end, and to close the open end of the cavern to seal the cavern in the fluid stored in the cavern It is provided with a plug in which the contact surface which is caught by contact with the underground rock when pressurized is formed,
One end of the cavern is installed in the state inserted into the plug, the high pressure fluid storage tank, characterized in that the outer surface of the plug in close contact with the rock by the pressure of the fluid.

Where the high-pressure fluid is stored, the cavern formed by excavating the rock in the underground core in an open shape at one end, and to close the open end of the cavern to seal the cavern in the fluid stored in the cavern It is provided with a plug in which the contact surface which is caught by contact with the underground rock when pressurized is formed,
A high pressure fluid storage tank, characterized in that a recess is formed at the end of the plug so as to communicate with the cavern, the outer surface of the plug is in close contact with the rock by the pressure of the fluid.

The method according to claim 1 or 2,
The plug includes a taper portion that gradually decreases in diameter in a direction away from the cavern, wherein the outer surface of the taper portion forms the contact surface.

The method according to claim 1 or 2,
The plug is a wedge type having an enlarged portion that gradually increases in diameter along a direction away from the cavern, and a reduced portion that gradually decreases in diameter from an end portion of the expanded portion, wherein an outer surface of the reduced portion forms the contact surface. High pressure fluid reservoir.

The method according to claim 1 or 2,
High pressure fluid reservoir, characterized in that the plug is formed in a cylindrical shape.

The method according to claim 1 or 2,
The plug is formed with a hole penetrating between one side and the other side, the hole is a high-pressure fluid reservoir, characterized in that the opening and closing.

The method according to claim 1 or 2,
The cavern is a high pressure fluid reservoir, characterized in that the tunnel shape or silo shape.

The method of claim 2,
High pressure fluid reservoir, characterized in that the airtight material is attached to the groove portion of the plug in contact with the cavern.