A drainage structure for underground gas storage

Abstract

The present invention discloses a drainage structure for an underground gas storage reservoir, and relates to the technical field of compressed air energy storage. The drainage structure comprises a water collection pipe, the pipe body of the water collection pipe has a plurality of water collection holes, one end of the water collection pipe is connected with the pipe body of an annular water diversion pipe, the annular water diversion pipe is located in an area filled with concrete, the annular water diversion pipe sleeve is annular, the annular water diversion pipe sleeve is arranged on the outside of a steel lining and is spaced from the outside of the steel lining, a water diversion pipe system is arranged at the bottom of the annular water diversion pipe, and groundwater in the water diversion pipe system is discharged through a pumping device. The drainage structure for an underground gas storage reservoir of the present invention solves the technical problem that groundwater is easily accumulated outside the steel lining of an existing underground gas storage reservoir, and has the advantage of being able to timely discharge groundwater outside the steel lining.

Description

Technical Field

[0001] The invention relates to the technical field of compressed air energy storage, and in particular to a drainage structure for an underground gas storage reservoir. Background Art

[0002] Compressed air energy storage power stations use compressed air energy storage systems to generate electricity. Compressed air energy storage systems are a technology that uses compressed air to store energy. When storing energy, the electric motor drives the multi-stage compressor to compress the air to high pressure and store it in the air storage device, completing the conversion of electrical energy to air pressure energy. When releasing energy, the compressed air is released from the air storage device and passed into the multi-stage expander to perform work, completing the conversion of air pressure energy to electrical energy.

[0003] One way to implement a gas storage device is to build an underground artificial cavern, namely an underground gas storage, which has the advantage of large gas storage capacity and is more suitable for large-scale compressed air energy storage systems. Underground gas storage is usually built in areas rich in hard rocks. In order to ensure sealing and be suitable for frequent filling and deflation, underground gas storage usually uses steel lining as sealing material, and concrete lining is filled between the outer side of the steel lining and the hard rock, and the inside of the steel lining is the gas storage space.

[0004] In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: areas rich in hard rocks have abundant groundwater, and frequent inflation and deflation of underground gas storage reservoirs can easily cause the outer side of the steel lining to separate from the concrete layer. Cracks will appear in the concrete layer under cyclic pressure, and groundwater will gather on the outer surface of the steel lining through the cracks in the concrete layer. If it is not discharged in time, it will not only cause a large external water pressure on the steel lining, but may also corrode the steel lining, thereby affecting the overall safety and stability of the gas storage reservoir. Summary of the invention

[0005] The object of the present invention is to provide a drainage structure for an underground gas storage reservoir which can timely discharge groundwater outside a steel lining.

[0006] To achieve this purpose, on the one hand, a drainage structure for an underground gas storage reservoir is provided, which is located in an underground rock mass, wherein the innermost layer of the gas storage cavern of the underground gas storage reservoir is a steel lining, the outer side of the steel lining is concrete, and the outer side of the concrete is surrounding rock; the drainage structure comprises a water collection pipe, the pipe body of the water collection pipe has a plurality of water collection holes, and the water collection holes collect groundwater into the water collection pipe; one end of the water collection pipe is connected with the pipe body of an annular water diversion pipe, the annular water diversion pipe is located in the concrete-filled area, and the connection point between the water collection pipe and the annular water diversion pipe is located in the concrete-filled area; the annular water diversion pipe sleeve is annular, and the annular water diversion pipe sleeve is arranged on the outer side of the steel lining and is spaced from the outer side of the steel lining; a water diversion pipe system is arranged at the bottom of the annular water diversion pipe, and the groundwater in the water collection pipe enters the water diversion pipe system through the annular water diversion pipe, and then enters the sump of the underground gas storage reservoir through the water diversion pipe system.

[0007] Furthermore, a drainage hole is drilled on the surrounding rock, and the other end of the water collecting pipe is fixed in the drainage hole.

[0008] Furthermore, the outer side of the water collection pipe is wrapped with geotextile.

[0009] Furthermore, the groundwater in the sump is discharged through a pumping device, or the groundwater in the sump is discharged naturally according to the elevation difference.

[0010] Furthermore, the lowest point of the water collecting pipe is the point where it is connected with the annular water diversion pipe.

[0011] Furthermore, a plurality of water collecting pipes are arranged on the annular water diversion pipe, and the plurality of water collecting pipes are arranged in an annular array around the annular water diversion pipe.

[0012] Furthermore, all of the water collection pipes are located above the waist of the steel lining.

[0013] Furthermore, the drainage structure includes a plurality of groups of annular water diversion pipes.

[0014] Furthermore, the water collection pipe is made of steel flower pipe.

[0015] Furthermore, the annular water diversion pipe is made of a seamless steel pipe.

[0016] One of the above technical solutions has the following advantages or beneficial effects: the drainage structure includes a water collection pipe, the water collection pipe body has a plurality of water collection holes, and the water collection holes collect groundwater into the water collection pipe. One end of the water collection pipe is connected with the pipe body of the annular water diversion pipe, the annular water diversion pipe is located in the area filled with concrete, and the connection between the water collection pipe and the annular water diversion pipe is located in the area filled with concrete. The annular water diversion pipe sleeve is annular, and is sleeved on the outside of the steel lining and arranged at intervals with the outside of the steel lining. A water diversion pipe system is arranged at the bottom of the annular water diversion pipe, and the groundwater in the water collection pipe enters the water diversion pipe system through the annular water diversion pipe, and the groundwater in the water diversion pipe system is discharged through a pumping device. The drainage process of the above drainage structure is: the groundwater is collected into the water collection pipe through the water collection holes, the water collection pipe is connected with the annular water diversion pipe, and the groundwater in the water collection pipe flows into the annular water diversion pipe, and then is discharged through the water diversion pipe system located at the bottom of the annular water diversion pipe.

[0017] The drainage structure of the present invention can timely collect and guide the groundwater in the surrounding rock of the underground gas storage reservoir, prevent the groundwater in the surrounding rock from seeping into the outside of the steel lining, thereby reducing the external water pressure of the steel lining, avoiding rusting of the steel lining, and enabling the underground gas storage reservoir to operate continuously and stably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a three-dimensional schematic diagram of a drainage structure for an underground gas storage in an embodiment at one angle;

[0019] Figure 2 is a three-dimensional schematic diagram of the drainage structure of the underground gas storage in the embodiment from another angle;

[0020] Figure 3 yes Figure 1 Schematic diagram of cross section;

[0021] Figure 4 yes Figure 3 A partial enlarged view of

[0022] Figure 5 yes Figure 2 A partial enlarged view of .

[0023] In the figure: 10-drainage structure; 11-water collection pipe; 111-water collection hole; 12-annular water diversion pipe; 121-front group of annular water diversion pipes; 122-rear group of annular water diversion pipes; 13-longitudinal water diversion pipe; 21-rock mass; 22-steel lining; 23-concrete; 211-drainage hole. DETAILED DESCRIPTION

[0024] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0025] The underground gas storage is located in an area with stable rock mass structure, and includes at least one group of gas storage caverns, construction passages and connecting tunnels. The shape of the gas storage cavern can adopt any existing one, such as barrel-shaped, strip-shaped flat caverns, annular flat caverns, etc. The cross-section of the gas storage cavern can be of any shape. Since the gas storage cavern is used to store compressed air in a medium- and high-pressure state, the common cross-section is circular. The drainage structure of the present invention can be used for underground gas storages of any shape.

[0026] like Figure 1-Figure 5 As shown, the innermost layer of the gas storage cavern in the underground gas storage uses a steel liner 22 as a sealing material, the sealed space surrounded by the steel liner 22 is the area for storing compressed air, and the outer side of the steel liner 22 and the surrounding rock mass 21 are filled with concrete 23. When constructing the underground gas storage, an area for gas storage is first excavated in the underground rock mass 21 by means of blasting, and then a steel liner 22 layer is constructed in the area, and finally backfilled with concrete 23. The drainage structure 10 of this embodiment is arranged in the concrete 23 layer and the surrounding rock layer outside it.

[0027] As Figure 1-Figure 5 The specific structure of the drainage structure 10 is described based on the direction of the drainage structure for underground gas storage in the use state shown. The drainage structure 10 of the underground gas storage in this embodiment includes an annular water diversion pipe 12 located in the concrete 23 and a water collection pipe 11 connected to the pipe body of the annular water diversion pipe 12. The connection between the water collection pipe and the annular water diversion pipe is located in the area filled with concrete, the annular water diversion pipe 12 is located in the area filled with concrete 23, the annular water diversion pipe sleeve is annular, arranged around the steel lining 22 of the gas storage cavern, and is arranged at a distance from the outside of the steel lining 22 and sleeved on the outside of the steel lining 22 of the gas storage cavern. The annular water diversion pipe 12 can be made of pipe material bent into an annular shape. As a preferred annular water diversion pipe 12, a steel pipe, especially a seamless steel pipe, is used. The annular water diversion pipe 12 of the drainage structure 10 is used to guide groundwater, and the water collection pipe 11 connected to the annular water diversion pipe 12 is used to collect groundwater at the surrounding rock.

[0028] like Figure 4As shown, the pipe body of the water collection pipe 11 has a plurality of water collection holes 111. One end of the water collection pipe 11 is located in the concrete layer 23 of the underground gas storage reservoir and is connected to the side wall of the pipe body of the annular water diversion pipe 12. A drainage hole 211 is drilled on the surrounding rock, and one end of the water collection pipe 11 is connected to the annular water diversion pipe 12 in the area filled with concrete, and the other end of the water collection pipe 11 is fixed in the drainage hole 211. Furthermore, the other end of the water collection pipe 11 is buried in the surrounding rock, or the other end of the water collection pipe 11 passes through the surrounding rock. During installation, drainage holes 211 are first drilled on the surrounding rock around the gas storage cavern, and the water collection pipe 11 is inserted into the drainage holes 211. Preferably, geotextile is wrapped on the outside of the water collection pipe 11, and the water collection pipe 11 wrapped with geotextile is inserted into the drainage hole 211. Wrapping the geotextile on the outside of the water collection pipe 11 is used to prevent the water collection holes 111 thereon from being blocked.

[0029] like Figure 1-Figure 4 As shown in the figure, a water diversion pipe system is arranged at the bottom of the annular water diversion pipe, and the groundwater in the water collection pipe enters the water diversion pipe system through the annular water diversion pipe, and then passes into the sump of the underground gas storage reservoir through the water diversion pipe system. When in use, the groundwater infiltrates into the water collection pipe 11 through the water collection hole 111 on the water collection pipe 11, and flows into the annular water diversion pipe under the action of gravity. In the annular water diversion pipe, the groundwater flows into the water diversion pipe system under the action of gravity. The water diversion pipe system passes into the sump of the underground gas storage reservoir, and the sump is located in the construction channel or the connecting lane. If the elevation of the underground gas storage reservoir relative to the drainage ground is small, then there is a pumping device in the sump, and the water is pumped out of the underground gas storage reservoir by the pumping device. The pumping device can adopt any existing one, such as a water pump. If the elevation of the underground gas storage reservoir relative to the drainage ground is large, the groundwater in the sump is naturally discharged according to the elevation difference.

[0030] Compared with the prior art, the drainage structure of the present invention can timely collect and guide the groundwater in the surrounding rock of the underground gas storage reservoir, prevent the groundwater in the surrounding rock from seeping into the outside of the steel lining, thereby reducing the external water pressure of the steel lining, avoiding rusting of the steel lining, and enabling the underground gas storage reservoir to operate continuously and stably for a long time.

[0031] like Figure 1-Figure 5 As shown, a plurality of water collecting pipes are arranged on the annular water diversion pipe, and the plurality of water collecting pipes 11 are arranged in an annular array along the annular water diversion pipe 12. Further, there are multiple groups of annular water diversion pipes, and the multiple groups of annular water diversion pipes are arranged in a longitudinal linear array along the underground gas storage reservoir, and each group of annular water diversion pipes 12 has a plurality of water collecting pipes 11 in an annular array. Further, as Figure 5 As shown, in two adjacent groups of annular water pipes 12, the water collecting pipes 11 on the front group of annular water pipes 121 and the water collecting pipes 11 on the rear group of annular water pipes 122 are arranged alternately, which can better collect groundwater.

[0032] like Figure 1-Figure 3As shown, the water diversion pipe system includes a longitudinal water diversion pipe 13, the pipe body of the longitudinal water diversion pipe 13 is connected to the bottom of all the annular water diversion pipes 12, and the end of the longitudinal water diversion pipe 13 is connected to the water collection pit. When there are more than two water collection pits, the two ends of the longitudinal water diversion pipe 13 are respectively connected to the two water collection pits. Alternatively, one end of the longitudinal water diversion pipe 13 is connected to the water collection pit, and the other end is a closed end.

[0033] like Figure 1-Figure 3 As shown, all the water collecting pipes 11 are distributed in the upper part of the annular water diversion pipe 12, that is, the water collecting pipes 11 are concentrated in the area above the waist of the steel lining of the gas storage cavern. The lower part of the annular water diversion pipe 12 is concentrated for water collection, which is suitable for working conditions with a large amount of groundwater.

[0034] like Figure 1-Figure 3 As shown, the water collection pipe 11 and the annular water diversion pipe 12 are arranged approximately vertically. Further, the water collection pipes 11 are arranged upward as a whole, that is, the end of the water collection pipe 11 located at the surrounding rock is higher than the end connected with the annular water diversion pipe 12, that is, the lowest point of the water collection pipe is the connection point between the annular water diversion pipe 12. Further, the angle between the water collection pipe 11 and the annular water diversion pipe 12 arranged close to the side is an acute angle.

[0035] The underground gas storage used for compressed air energy storage power stations needs to be frequently inflated and deflated during operation. That is, the underground gas storage is inflated when storing energy, and deflated when releasing energy. When the underground gas storage is inflated, the gas storage pressure in the steel lining 22 increases, the steel lining 22 expands, and the above-mentioned gas storage pressure is transmitted to the surrounding rock through the concrete 23, and the surrounding rock mainly bears the above-mentioned gas storage pressure. When the gas storage is deflated, the steel lining 22 shrinks, and the gas storage pressure in the steel lining 22 decreases. Under the above working conditions, the concrete 23 layer is very easy to crack. When the concrete 23 layer is partially cracked, the groundwater in the surrounding rock will penetrate into the concrete 23 layer, and then further gather on the outside of the steel lining 22. The design life of the compressed air energy storage power station is more than 30 years. As time goes by, the groundwater outside the steel lining 22 gathers, which will not only cause a large external water pressure on the steel lining 22, but also corrode the steel lining 22.

[0036] Based on this, the underground gas storage reservoir containing the above-mentioned drainage structure 10 is particularly suitable for compressed air energy storage power stations, which can timely collect and guide the flow direction of groundwater, and collect it to the fixed drainage area in the gas storage reservoir, preventing groundwater from gathering outside the steel lining 22 of the gas storage cavern, thereby ensuring the long-term continuous and safe operation of the underground gas storage reservoir, thereby ensuring the long-term, continuous, stable and safe operation of the compressed air energy storage power station. The above-mentioned compressed air energy storage power station can be used for large-scale compressed air energy storage.

[0037] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A drainage structure for an underground gas storage reservoir, located in an underground rock mass, wherein the innermost layer of the gas storage cavern of the underground gas storage reservoir is a steel lining, the outer side of the steel lining is concrete, and the outer side of the concrete is surrounding rock; characterized in that: The drainage structure comprises a water collection pipe, the water collection pipe body has a plurality of water collection holes, and the water collection holes collect groundwater into the water collection pipe; one end of the water collection pipe is connected with the pipe body of the annular water diversion pipe, the annular water diversion pipe is located in the concrete-filled area, and the connection point between the water collection pipe and the annular water diversion pipe is located in the concrete-filled area; the annular water diversion pipe sleeve is annular, and the annular water diversion pipe sleeve is arranged on the outside of the steel liner and is spaced from the outside of the steel liner; A water diversion pipe system is arranged at the bottom of the annular water diversion pipe, and the groundwater in the water collecting pipe enters the water diversion pipe system through the annular water diversion pipe, and then flows into the water collection pit of the underground gas storage reservoir through the water diversion pipe system.

2. The drainage structure for underground gas storage according to claim 1, characterized in that: A drainage hole is drilled on the surrounding rock, and the other end of the water collecting pipe is fixed in the drainage hole.

3. The drainage structure for underground gas storage according to claim 1, characterized in that: The outer side of the water collecting pipe is wrapped with geotextile.

4. The drainage structure for underground gas storage according to claim 1, characterized in that: The groundwater in the sump is discharged through a pumping device, or the groundwater in the sump is discharged naturally according to the elevation difference.

5. The drainage structure for underground gas storage according to claim 1, characterized in that: The lowest point of the water collecting pipe is the connection point between the water collecting pipe and the annular water diversion pipe.

6. The drainage structure for underground gas storage according to claim 1, characterized in that: A plurality of water collecting pipes are arranged on the annular water diversion pipe, and the plurality of water collecting pipes are arranged in an annular array around the annular water diversion pipe.

7. The drainage structure for underground gas storage according to claim 6, characterized in that: All of the water collection pipes are located above the waist of the steel lining.

8. The drainage structure for underground gas storage according to claim 6, characterized in that: The drainage structure comprises a plurality of groups of annular water diversion pipes.

9. The drainage structure for underground gas storage according to claim 1, characterized in that: The water collecting pipe is a steel flower pipe.

10. The drainage structure for underground gas storage according to claim 1, characterized in that: The annular water diversion pipe is made of seamless steel pipe.

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