Compressed air energy storage underground cavern model test system designed according to preset joints

Abstract

A compressed air energy storage underground cavern model test system designed according to a preset joint disclosed by the present invention comprises a simulation cavern, a loading system, a measurement system and a protection device, the measurement system comprises a plurality of temperature sensors, a plurality of pressure sensors, a plurality of crack meters and a plurality of optical fiber gas sensors, and the simulation cavern comprises a steel cylinder sealed by a sealing door. A deformation simulation layer, a lining layer, a leveling layer, a geotechnical cloth layer and a flexible sealing layer are arranged on the inner wall of the steel cylinder, a plurality of longitudinal exhaust pipelines are embedded in the joint of the deformation simulation layer and the lining layer, a plurality of exhaust pipes are inserted into the cylinder wall of the steel cylinder, each exhaust pipe is communicated with one longitudinal exhaust pipeline, a plurality of longitudinal prefabricated cracks are distributed in the lining layer, and the longitudinal prefabricated cracks are communicated with the geotechnical cloth layer. A crack meter is embedded in the middle of each longitudinal prefabricated crack, and the simulation cavern is communicated with the loading system through an air inlet in the sealing door. The test system is low in cost, convenient to operate, large in scale, comprehensive in test item, high in test precision and high in reference value for actual engineering.

Description

Technical Field

[0001] The invention relates to the field of underground energy storage, and in particular to a compressed air energy storage underground cavern model testing system designed according to preset joints. Background Art

[0002] The sealing performance of compressed gas energy storage underground caverns is crucial to the efficiency and safety of the system. Compressed gas energy storage underground caverns usually use steel plates or flexible sealing layers for cavern sealing, and flexible sealing layers have great application prospects due to their low cost. When a flexible sealing layer is used, there are usually two design schemes for the lining of the underground cavern. One is to design a full-ring lining and meet the crack limit requirements. This design scheme is usually suitable for occasions with good surrounding rock conditions and small surrounding rock deformation.

[0003] We found that when the surrounding rock quality is medium and the surrounding rock deformation is large, the lining structure can be designed according to the preset joints, and the radial displacement of the lining can be released through the preset joints to make the lining meet the crack limit requirements. Testing the sealing and mechanical properties of the compressed air storage underground cavern model designed according to the preset joints can verify the influence of the prefabricated cracks in the lining on the flexible sealing layer, test the air tightness of different sealing layer splicing methods, determine the appropriate splicing method, and verify the accuracy of the air tightness calculation theory of the flexible sealed compressed air storage underground cavern, and verify the feasibility of the leakage monitoring method of the flexible sealing layer of the compressed air storage underground cavern, so as to better guide the implementation of the project. The scheme of using on-site testing is expensive and the site is limited. Using indoor small-scale physical model tests will be difficult to reflect the real mechanical state due to the size effect. Therefore, the present invention proposes a compressed air storage underground cavern model test system designed according to preset joints to simulate the compressed air storage underground cavern designed according to preset joints, so as to be as close to the test effect of the on-site test as possible. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a compressed air energy storage underground cavern model testing system designed with preset joints in view of the shortcomings of the prior art. The testing system has low cost, is easy to operate, is large in scale, is closer to the actual situation, and has more comprehensive test items and higher test accuracy, which is more valuable for reference to actual projects.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a compressed air energy storage underground cave model test system designed according to a preset joint, including a simulated cave, a loading system, a measuring system and a protective device, the loading system is used to load air pressure on the simulated cave, the measuring system is used to test the sealing performance and mechanical properties of the simulated cave, the measuring system includes a plurality of temperature sensors, a plurality of pressure sensors, a plurality of crack meters and a plurality of optical fiber gas sensors, the protective device includes a protective ground and protective walls built on both sides of the protective ground, the simulated cave includes a horizontally placed steel cylinder, the diameter of the steel cylinder is 2 to 3m and the length is 3 to 5m, the steel cylinder is fixed on the protective ground through a support, a head is welded at one end of the steel cylinder, and the other end of the steel cylinder is sealed by an openable and closable sealing door, the inner wall of the steel cylinder is sequentially arranged with a deformation simulation layer, a lining layer, a leveling layer, a geotextile layer and a flexible sealing layer, the deformation simulation layer is used to simulate the deformation of the surrounding rock, and the deformation simulation layer and the flexible sealing layer are respectively composed of soft materials. The lining layer is composed of concrete, the leveling layer is composed of cement mortar, and the geotextile layer is composed of geotextile. A plurality of longitudinal exhaust pipes are buried at the junction of the deformation simulation layer and the lining layer. A plurality of exhaust holes are opened on the wall of the steel cylinder. An exhaust pipe is inserted at each of the exhaust holes. Each of the exhaust pipes is connected with a longitudinal exhaust pipe. A plurality of longitudinal prefabricated cracks are evenly distributed in the lining layer. A crack meter is pre-buried in the middle of each longitudinal prefabricated crack. The plurality of temperature sensors and the plurality of pressure sensors are respectively arranged in the simulation cave. The plurality of optical fiber gas sensors are respectively buried in the lining layer and are arranged at equal intervals along the circumference of the lining layer. Each optical fiber gas sensor is arranged in the longitudinal direction of the lining layer. A plurality of lead pipes for routing the measurement system are respectively opened on the wall of the steel cylinder and on the sealing door. An air inlet is arranged on the sealing door. The simulation cave is connected with the loading system through the air inlet.

[0006] The compressed air energy storage underground cavern model test system designed according to the preset joints of the present invention can test the sealing performance and mechanical properties of the simulated cavern, and monitor the thermodynamic properties of the air by testing the air temperature and air pressure in the simulated cavern; monitor the change of the width of the longitudinal prefabricated crack by testing the crack width; monitor the air tightness of the flexible sealing layer by testing the temperature of the leakage position, and discharge the gas that penetrates through the flexible sealing layer and into the lining layer out of the simulated cavern through the exhaust pipe, so as to reversely calculate the air tightness of the flexible sealing layer in the simulated cavern according to the change of the air pressure in the simulated cavern; and monitor the temperature of the tested flexible sealing layer by testing the temperature of the flexible sealing layer.

[0007] The test system of the present invention makes the selection of test sites more flexible, and compared with on-site testing, the cost is lower and the test operation is more convenient; compared with small-scale model tests, the test system of the present invention is larger in scale, closer to the actual situation, and has higher test accuracy; compared with existing physical model tests, the test system of the present invention tests more complete items, including all tests including surrounding rock, lining layer, flexible sealing layer and air, and is more valuable for reference to actual projects.

[0008] The inner wall of the steel cylinder of the test system of the present invention is arranged with a deformation simulation layer, a lining layer, a leveling layer, a geotextile layer and a flexible sealing layer in sequence. The function of the deformation simulation layer is to simulate the deformation of the surrounding rock; the function of the leveling layer is to level the inner surface of the lining layer to prevent the sealing effect of the flexible sealing layer from being affected by the uneven inner surface of the lining layer; the function of the geotextile layer is to prevent the flexible sealing layer from directly contacting the lining layer, reducing friction, and facilitating a certain sliding displacement between the flexible sealing layer and the lining layer.

[0009] Since the outermost side of the simulated cavern is constrained by the steel cylinder, the lining layer cannot be deformed. In order to obtain the expansion information of the preset longitudinal prefabricated cracks, the present invention simulates the deformation of the surrounding rock by setting a deformation simulation layer between the inner wall of the steel cylinder and the lining layer, thereby obtaining the expansion information of the preset longitudinal prefabricated cracks. The deformation simulation layer adopts a soft material with good deformation ability.

[0010] Preferably, the loading system comprises a gas charging and discharging pipeline, a gas storage tank and an air compressor connected in sequence, a gas booster pump, a pressure gauge, a pressure sensor and a valve are installed on the gas charging and discharging pipeline, and the gas charging and discharging pipeline is connected to the air inlet.

[0011] Preferably, several of the temperature sensors are arranged in the middle of the simulated cave chamber, in the middle of the inner wall of the flexible sealing layer, and near the air inlet, and several of the pressure sensors are arranged in the middle of the simulated cave chamber and near the air inlet.

[0012] Preferably, the thickness of the deformation simulation layer is 3-8 cm, the thickness of the lining layer is 10-30 cm, the thickness of the leveling layer is 0.5-1 cm, the thickness of the geotextile layer is 0.5-1 cm, and the thickness of the flexible sealing layer is 3-10 mm.

[0013] Preferably, a steel ring is coaxially welded to the other end of the steel cylinder, and the sealing door is arranged outside the steel ring. The function of the steel ring is to seal the end of the lining layer to prevent the lining layer from contacting the sealing door and ensure the test effect.

[0014] Preferably, the soft material is butyl rubber, nitrile rubber, EPDM rubber or high-density polyethylene.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] (1) The compressed air energy storage underground cavern model test system designed with preset joints in the present invention makes the test site selection more flexible, and compared with on-site testing, the cost is lower and the test operation is more convenient;

[0017] (2) Compared with the small-scale model test, the test system of the present invention is larger in scale, closer to the actual situation, and has higher test accuracy;

[0018] (3) Compared with the existing physical model test, the test system of the present invention has more comprehensive test items, including all tests of surrounding rock, lining layer, flexible sealing layer and air, which is more valuable for reference to actual projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a longitudinal cross-sectional view of a compressed air energy storage underground cavern model test system designed according to a preset joint in the embodiment;

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0021] Figure 3 for Figure 1 Enlarged view of point B in the middle;

[0022] Figure 4 For the enlarged Figure 1 Middle CC section view;

[0023] The specific reference numerals in the figure are as follows:

[0024] 1-simulated cavern, 11-steel cylinder, 12-hemispherical head, 13-steel ring, 14-sealed door, 15-deformation simulation layer, 16-lining layer, 17-leveling layer, 18-geotextile layer, 19-flexible sealing layer, 10-air inlet, 21-charging and discharging pipelines, 22-gas storage tanks, 23-air compressors, 31-temperature sensors, 32-pressure sensors, 33-crack meters, 34-fiber optic gas sensors, 35-lead tubes, 41-protective ground, 42-protective wall, 43-supports, 51-longitudinal exhaust ducts, 52-exhaust holes, 53-exhaust pipes, 6-longitudinal prefabricated cracks, 7-sealing strips. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the embodiments of the drawings. The devices, materials, structures or components not limited in the present invention all adopt conventional technical means in the art.

[0026] Embodiment: A compressed air energy storage underground cavern model test system designed with preset joints, such as Figure 1 to Figure 4 As shown, it includes a simulated cave 1, a loading system, a measuring system and a protective device. The loading system is used to load air pressure on the simulated cave 1. The measuring system is used to test the sealing performance and mechanical properties of the simulated cave 1. The measuring system includes a plurality of temperature sensors 31, a plurality of pressure sensors 32, a plurality of crack meters 33 and a plurality of optical fiber gas sensors 34. The protective device includes a protective ground 41 and protective walls 42 built on both sides of the protective ground 41. The thickness of the protective wall 42 on one side is more than 400 mm and the area is more than 10m 2 The simulated cavern 1 includes a horizontally placed steel cylinder 11, which is fixed on the protective ground 41 through a support 43. In this embodiment, the steel cylinder 11 is made of Q420 steel with a main body thickness of 10 mm, a diameter of 2 m and a length of 3 m. A hemispherical head 12 is welded at one end of the steel cylinder 11 and the inner cavity of the hemispherical head 12 is filled with a steel block. A steel ring 13 is coaxially welded at the other end of the steel cylinder 11. A sealing door 14 with a diameter of 2 m is provided on the outer side of the steel ring 13. The inner wall of the steel cylinder 11 is sequentially arranged with a deformation simulation layer 15, a lining layer 16, and a sealing layer 17. The masonry layer 16, the leveling layer 17, the geotextile layer 18 and the flexible sealing layer 19, the deformation simulation layer 15 is used to simulate the deformation of the surrounding rock, the deformation simulation layer 15 and the flexible sealing layer 19 are both made of butyl rubber, the lining layer 16 is made of C30 plain concrete, the leveling layer 17 is made of cement mortar, the geotextile layer 18 is made of geotextile, two longitudinal exhaust pipes 51 are buried at the junction of the deformation simulation layer 15 and the lining layer 16, four exhaust holes 52 are respectively opened at the top and bottom of the cylinder wall of the steel cylinder 11, and an exhaust pipe 53 is inserted at each exhaust hole 52. Each exhaust pipe 53 is connected to a longitudinal exhaust duct 51. Four longitudinal prefabricated cracks 6 are evenly arranged in the lining layer 16 at a spacing of 90 degrees. The widths of the four longitudinal prefabricated cracks 6 are 0.5 mm, 1.5 mm, 3 mm, and 4.5 mm, respectively. The four longitudinal prefabricated cracks 6 are arranged along the longitudinal length of the simulated cavern 1. A crack meter 33 is pre-buried in the middle of each longitudinal prefabricated crack 6 to obtain the width change information of the longitudinal prefabricated crack 6. An air inlet 10 is provided on the sealing door 14. The simulated cavern 1 is connected to the loading system through the air inlet 10. Specifically, a number of temperature sensors 31 are arranged in the middle of the simulated cavern 1, in the middle of the inner wall of the flexible sealing layer 19, and near the air inlet 10, respectively; a number of pressure sensors 32 are arranged in the middle of the simulated cavern 1 and near the air inlet 10, respectively; a number of optical fiber gas sensors 34 are respectively buried in the lining layer 16 and arranged at equal intervals along the circumference of the lining layer 16, and each optical fiber gas sensor 34 is arranged along the longitudinal direction of the lining layer 16; a number of lead tubes 35 for wiring of the measurement system are respectively opened on the wall of the steel cylinder 11 and the sealing door 14.

[0027] In this embodiment, the loading system includes a charging and discharging air pipeline 21, an air storage tank 22 and an air compressor 23 connected in sequence. A gas booster pump, a pressure gauge, a pressure sensor and a valve (not shown in the figure) are installed on the charging and discharging air pipeline 21, and the charging and discharging air pipeline 21 is connected to the air inlet 10.

[0028] In this embodiment, the thickness of the deformation simulation layer 15 is 5 cm, the thickness of the lining layer 16 is 20 cm, the thickness of the leveling layer 17 is 1 cm, the thickness of the geotextile layer 18 is 0.5 cm, and the thickness of the flexible sealing layer 19 is 6 mm. The maximum operating pressure of the simulated cavern 1 is designed to be 12 MPa.

[0029] In this embodiment, the flexible sealing layer 19 is constructed by existing technology. For example, two rubber plates are prefabricated into rubber rings by existing splicing methods such as I-shaped splicing and overlapping of overlying sheets. The rubber plates are anchored at the overlap by anchoring, and anchor sleeves are pre-embedded in the lining layer 16 at the overlap of the rubber edge according to the set anchor bolt spacing to facilitate the insertion of bolts. When the rubber is overlapped, the bolts are successively passed through the flexible sealing layer 19 and the geotextile layer 18 and finally inserted into the sleeve pre-embedded in the lining layer 16 and tightened to achieve anchoring. In order to improve the air tightness of the overlap and anchoring, adhesive is applied to the inner side of the two overlapping layers of rubber, and sealing strips 7 are provided at both ends of the overlap.

[0030] The above-mentioned compressed air energy storage underground cavern model test system designed according to the preset joints can flexibly select the test site for testing. Compared with on-site testing, it has lower costs, more convenient test operations, and larger scale, closer to the actual situation, higher test accuracy, and complete test items, which is more valuable for reference to actual projects. Specifically, the test system monitors the thermodynamic properties of air by testing the air temperature and air pressure in the simulated cavern 1; monitors the change in the width of the longitudinal prefabricated crack 6 by testing the crack width; monitors the air tightness of the flexible sealing layer 19 by testing the temperature of the leaking position, and discharges the gas that penetrates through the flexible sealing layer 19 into the lining layer 16 from the simulated cavern 1 through the exhaust pipe 53, so as to reversely calculate the air tightness of the flexible sealing layer 19 in the simulated cavern 1 according to the change in the air pressure in the simulated cavern 1; and monitors the temperature of the flexible sealing layer 19 by testing the temperature of the flexible sealing layer 19.

Claims

1. A compressed air energy storage underground cavern model test system designed with preset joints, characterized in that: It includes a simulated cavern, a loading system, a measuring system and a protective device. The loading system is used to load air pressure on the simulated cavern. The measuring system is used to test the sealing performance and mechanical properties of the simulated cavern. The measuring system includes a plurality of temperature sensors, a plurality of pressure sensors, a plurality of crack meters and a plurality of optical fiber gas sensors. The protective device includes a protective ground and protective walls built on both sides of the protective ground. The simulated cavern includes a horizontally placed steel cylinder. The diameter of the steel cylinder is 2 to 3 meters and the length is 3 to 5 meters. The steel cylinder is fixed on the protective ground through a support. A sealing head is welded at one end of the steel cylinder. The other end of the steel cylinder is sealed by an openable and closable sealing door. The inner wall of the steel cylinder is sequentially arranged with a deformation simulation layer, a lining layer, a leveling layer, a geotextile layer and a flexible sealing layer. The deformation simulation layer is used to simulate the deformation of the surrounding rock. The deformation simulation layer and the flexible sealing layer are respectively composed of soft materials. The lining layer is composed of concrete. The leveling layer is composed of The geotextile layer is composed of geotextile, a plurality of longitudinal exhaust pipes are buried at the junction of the deformation simulation layer and the lining layer, a plurality of exhaust holes are opened on the wall of the steel cylinder, an exhaust pipe is inserted at each exhaust hole, each exhaust pipe is connected with a longitudinal exhaust pipe, a plurality of longitudinal prefabricated cracks are evenly distributed in the lining layer, a crack meter is pre-buried in the middle position of each longitudinal prefabricated crack, the plurality of temperature sensors and the plurality of pressure sensors are respectively arranged in the simulation cave, the plurality of optical fiber gas sensors are respectively buried in the lining layer and are arranged at equal intervals along the circumference of the lining layer, each optical fiber gas sensor is arranged in the longitudinal direction of the lining layer, a plurality of lead-in tubes for routing the measurement system are respectively opened on the wall of the steel cylinder and the sealing door, an air inlet is arranged on the sealing door, and the simulation cave is communicated with the loading system through the air inlet.

2. The compressed air energy storage underground cavern model testing system designed with preset joints according to claim 1 is characterized in that: The loading system comprises a gas charging and discharging pipeline, a gas storage tank and an air compressor connected in sequence, a gas booster pump, a pressure gauge, a pressure sensor and a valve are installed on the gas charging and discharging pipeline, and the gas charging and discharging pipeline is connected to the air inlet.

3. The compressed air energy storage underground cavern model testing system designed with preset joints according to claim 1 is characterized in that: Several temperature sensors are arranged in the middle of the simulated cave, in the middle of the inner wall of the flexible sealing layer, and near the air inlet, and several pressure sensors are arranged in the middle of the simulated cave and near the air inlet.

4. The compressed air energy storage underground cavern model testing system designed with preset joints according to claim 1 is characterized in that: The thickness of the deformation simulation layer is 3-8 cm, the thickness of the lining layer is 10-30 cm, the thickness of the leveling layer is 0.5-1 cm, the thickness of the geotextile layer is 0.5-1 cm, and the thickness of the flexible sealing layer is 3-10 mm.

5. The compressed air energy storage underground cavern model testing system designed with preset joints according to claim 1 is characterized in that: A steel ring is coaxially welded to the other end of the steel cylinder, and the sealing door is arranged on the outer side of the steel ring.

6. The compressed air energy storage underground cavern model testing system designed with preset joints according to claim 1 is characterized in that: The soft material is butyl rubber, nitrile rubber, EPDM rubber or high-density polyethylene.

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