Pressurizing device and pressurizing structure for lining test of compressed air energy storage underground cavern

Abstract

The present application relates to compressed air energy storage field, especially to a kind of through mechanical pressure mode to realize pressurization to lining layer by compressed air energy storage underground cavern lining test pressurization device and pressurization structure, comprising: at least two arc-shaped pressing plate, arc-shaped pressing plate is enclosed and forms cylinder structure between;Counterforce shaft, the axis of counterforce shaft is coaxially arranged with the axis of cylinder structure, counterforce shaft is slidably arranged along the axis direction of counterforce shaft;Load conversion mechanism, load conversion mechanism is respectively connected with counterforce shaft and arc-shaped pressing plate;When counterforce shaft slides along the axis direction of counterforce shaft, load conversion mechanism drives arc-shaped pressing plate to slide along the axis direction perpendicular to counterforce shaft.The present application is especially suitable for the test occasion of realizing pressurization to annular lining.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage, and more particularly to a pressurization device and pressurization structure for testing the lining of an underground cavern for compressed air energy storage. Background Technology

[0002] Compressed air energy storage (CASS) boasts advantages such as large storage capacity, long storage cycle, high system efficiency, and long operational life, making it one of the most promising large-scale energy storage technologies. Specifically, CASS is analogous to installing a giant "air power bank" on the power grid. During periods of low electricity demand, it converts electrical energy into compressed air for storage, and releases this pressure during peak demand for power generation, thus becoming a stabilizer for the power grid and a crucial component of renewable energy. Structurally, the three elements constituting the underground rock-lined cavern of CASS energy storage are the sealing layer, lining, and surrounding rock. The sealing layer, typically made of steel or rubber, primarily seals the high-pressure gas. The lining, or concrete lining support structure, mainly transfers loads and protects the sealing layer. The surrounding rock bears most of the internal pressure load and is the primary load-bearer. The gas tightness of the air-storing cavern structure is a critical performance indicator for achieving effective CASS energy storage.

[0003] The patent application CN119534109A discloses a high-pressure gas storage tunnel model test device and method. It includes a test module, a confining pressure module, an overall foundation, and a pressurization module. The test module is a cylindrical structure with a sealed cavity in the middle. From the inside out, the test module consists of a sealing layer, a lining layer, and a surrounding rock layer. Monitoring sensors are installed inside the test module. The confining pressure module comprises multiple confining pressure devices arranged in a ring between the test module and the overall foundation. Each confining pressure device includes an elastic element and a pressure application device; the elastic element applies an external load to the test module. The pressurization module connects to the sealed cavity, introducing high-pressure gas into the sealed cavity to apply an internal load to the test module. Because the internal load of the test module is applied using high-pressure gas, this not only requires the sealed cavity to meet complex sealing structures and leak detection requirements but also increases the cost of the test. Furthermore, any leakage of the high-pressure gas could endanger the safety of personnel in the surrounding area. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a pressurization device and pressurization structure for testing the lining of an underground cavern with compressed air energy storage by mechanically applying pressure to pressurize the lining layer.

[0005] The technical solution adopted by this invention to solve its technical problem is: a pressurization device for lining test of compressed air energy storage underground cavern, comprising: at least two arc-shaped pressure plates, which together form a cylindrical structure; a reaction shaft, the axis of which is coaxial with the axis of the cylindrical structure, and the reaction shaft is slidably disposed along the axial direction of the reaction shaft; a load conversion mechanism, which is connected to the reaction shaft and the arc-shaped pressure plates respectively; when the reaction shaft slides along the axial direction of the reaction shaft, the load conversion mechanism drives the arc-shaped pressure plates to slide along the axial direction perpendicular to the reaction shaft.

[0006] Furthermore, the load conversion mechanism includes a connecting rod, which is obliquely arranged to the horizontal plane. One end of the connecting rod is hinged to the reaction axis, and the other end of the connecting rod is hinged to the arc-shaped pressure plate.

[0007] Furthermore, the connecting rods are evenly distributed around the axis of the reaction force.

[0008] Furthermore, the sidewalls of the arc-shaped pressure plate are provided with toothed edges, and the sidewalls of two adjacent arc-shaped pressure plates are engaged by the toothed edges.

[0009] Furthermore, it includes an axial force loading platform, the loading shaft of which is connected to the reaction shaft, and the loading shaft drives the reaction shaft to slide along the axial direction of the reaction shaft.

[0010] Furthermore, the axial force loading platform is fixedly connected to the platform via a support rod, which is circumferentially distributed around the axis of the reaction force axis.

[0011] Furthermore, it includes a controller that is connected to the loading axis of the axial force loading table.

[0012] Furthermore, the pressurization structure for the test of compressed air storage underground cavern lining includes a pressurization device for the test of compressed air storage underground cavern lining, which includes an annular lining. The cylindrical structure formed by the arc-shaped pressure plate is sleeved inside the annular lining, and the load conversion mechanism drives the arc-shaped pressure plate to slide towards the annular lining.

[0013] Furthermore, it includes a sleeve, which is fitted onto the outer periphery of the annular lining.

[0014] Furthermore, it includes strain gauges disposed on the outer surface of the annular lining; and a reinforcement gauge disposed inside the annular lining.

[0015] The beneficial effects of this invention are: I. In practical use, the annular lining (test object) is fitted onto the outer circumference of the cylindrical structure formed by the arc-shaped pressure plate. When the driving reaction shaft slides along its axial direction, the reaction shaft first drives the load conversion mechanism. Then, the moving load conversion mechanism drives the arc-shaped pressure plate to slide along its axial direction perpendicular to the reaction shaft. The sliding arc-shaped pressure plate is tightly attached to the sidewall of the annular lining and applies pressure to it in the radial direction, thus simulating the stress state of the annular lining under high-pressure gas. Subsequently, the mechanical property data of the annular lining under pressure can be obtained. This device can simulate lining cracking and mechanical properties under corresponding pressure conditions in a short time. It has a short test cycle and low cost, eliminating the need for complex sealing structures and leak detection requirements, as well as the safety hazards of high-pressure gas leakage. It also eliminates the safety hazards of high internal pressure and provides more stable and precise control of internal pressure.

[0016] Second, by hinged the two ends of the connecting rod to the reaction shaft and the arc-shaped pressure plate respectively, a force transmission mechanism is constructed to convert the driving force applied by the reaction shaft into the motion of the arc-shaped pressure plate. This allows the load conversion mechanism to drive the arc-shaped pressure plate to slide in a direction perpendicular to the reaction shaft's axis when the reaction shaft slides along its axial direction. This structure is more streamlined and has lower manufacturing costs.

[0017] Third, by having the side walls of two adjacent arc-shaped pressure plates interlocked with toothed edges, the pressure applied to the annular lining by the arc-shaped pressure plates when they move outward can be more even, effectively reducing the defect that pressure cannot be applied at the gap between the side walls of two adjacent arc-shaped pressure plates.

[0018] Fourth, to achieve rapid, stable and repeatable simulation of the "internal pressure effect", thereby efficiently obtaining the stress response, crack initiation threshold and crack propagation law under different lining thicknesses, material strength grades, prefabrication defects (such as construction joints, weak interfaces, initial cracks) and different loading paths (monotonic loading, graded steady loading, cyclic loading) in the laboratory.

[0019] This invention is particularly suitable for experimental applications involving pressurization of annular linings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of one embodiment of the present invention in actual use.

[0021] Figure 2 yes Figure 1 A sectional view.

[0022] Figure 3 This is a schematic diagram of the internal structure of the arc-shaped pressure plate when the annular lining is nested inside the arc-shaped pressure plate to form the outer circumference of the cylindrical structure.

[0023] Figure 4This is a schematic diagram showing the positional relationship between the annular lining, the reaction axis, and the connecting rod when the annular lining is nested inside the arc-shaped pressure plate to form the outer circumference of the cylindrical structure.

[0024] Figure 5 This is a schematic diagram showing how the side walls of two adjacent arc-shaped pressure plates are joined together by toothed edges.

[0025] Figure 6 This is a schematic diagram showing how, after the two ends of the connecting rod are hinged to the arc-shaped pressure plate connecting plate and the reaction shaft connecting plate respectively, the reaction shaft connecting plate slides upward, thereby reducing the distance between the arc-shaped pressure plate connecting plate and the reaction shaft connecting plate.

[0026] Figure 7 This is a schematic diagram showing that after the two ends of the connecting rod are hinged to the arc-shaped pressure plate connecting plate and the reaction shaft connecting plate respectively, the reaction shaft connecting plate slides downward, thereby increasing the distance between the arc-shaped pressure plate connecting plate and the reaction shaft connecting plate.

[0027] The components in the diagram are labeled as follows: axial force loading platform 1, loading shaft 101, reaction shaft loading seat 11, loading pressure sensor 12, bracket connecting plate 13, bracket connecting rod 14, reaction shaft 2, reaction shaft connecting plate 21, connecting rod 3, arc-shaped pressure plate 4, toothed edge 41, arc-shaped pressure plate connecting plate 42, annular lining 5, base 6, padding layer 7, sleeve 8, platform 9, controller 10. Detailed Implementation

[0028] The invention will be further described below with reference to the accompanying drawings.

[0029] Figures 1 to 7 The illustration shows an embodiment of the pressurization device and pressurization structure for the test lining of an underground cavern for compressed air energy storage.

[0030] like Figure 1As shown, platform 9 has a rectangular structure, with bases 6 at each of its four corners. The bases 6 are threaded into the bottom of platform 9, allowing platform 9 to be adjusted by rotating the bases 6, thus keeping its top surface level. A pressurization device for the compressed air storage underground cavern lining test is mounted on the top surface of platform 9, along with an annular lining 5 fitted around the device. The annular lining 5 is a cylindrical structure. In this embodiment, the annular lining 5 is manufactured at a 1:20 scale, and is cast and cured to the target strength. Four support rods 14 are evenly distributed circumferentially around the axis of the annular lining 5. The bottom of each support rod 14 is fixed to the top surface of platform 9, and the top of each support rod 14 is fixedly connected to a circular support connecting plate 13. The axial force loading platform 1 is fixedly connected to the support connecting plate 13. The outer wall of the arc-shaped pressure plate 4 of the pressurization device for the compressed air energy storage underground cavern lining test is tightly fitted to the inner wall of the annular lining 5. When the axial force loading platform 1 drives the reaction shaft 2 downward, the reaction shaft 2 drives the arc-shaped pressure plate 4 to move horizontally through the connecting rod 3, thereby applying an external force along the radial direction of the annular lining 5 to the cylindrical annular lining 5, simulating the state of the annular lining 5 under external air force during actual use. Based on this, a cushion layer 7 is fitted around the outer periphery of the annular lining 5, and a steel sleeve 8 is fitted around the outer periphery of the cushion layer 7. The cushion layer 7 simulates the deformation of the surrounding rock, while the steel sleeve 8 simulates the constraint effect on the surrounding rock. Of course, different cushion layer 7 materials can be used to simulate the deformation of the surrounding rock, making it easier to conduct mechanical response experiments of the lining under different surrounding rock conditions. Alternatively, the cushion layer 7 and sleeve 8 can be removed, exposing the annular lining 5, and the crack propagation of the lining can be observed using deformation monitoring instruments.

[0031] Figure 2 What is shown is Figure 1 A cross-sectional view is shown. A controller 10 is installed inside the platform 9, and the controller 10 is connected to the axial force loading platform 1. Specifically, the controller 10 can be a linear electro-hydraulic actuator. The controller 10 can apply hydraulic pressure to the axial force loading platform 1, causing the loading shaft 101 of the axial force loading platform 1 to move downwards, thereby driving the reaction shaft 2 downwards. Since the axial force loading platform 1 is fixedly connected to the top surface of the platform 9 through the bracket connecting plate 13 and the bracket connecting rod 14, the bracket connecting plate 13 and the bracket connecting rod 14 can ensure the stability of the position of the axial force loading platform 1 when the loading shaft 101 moves downwards. A loading pressure sensor 12 is installed inside the axial force loading platform 1 to monitor the pressure applied by the loading shaft 101 in real time. The arc-shaped pressure plate 4 moves in a direction perpendicular to the axis of the reaction shaft 2 and away from the reaction shaft 2. Preferably, ball bearings can be installed at the bottom of the arc-shaped pressure plate 4 to guide the arc-shaped pressure plate 4 to move smoothly in the horizontal direction.

[0032] like Figures 2 to 5As shown, several arc-shaped pressure plates 4 surround to form a cylindrical structure. A reaction shaft 2 is installed inside the cylindrical structure, with its axis coaxial with the axis of the cylindrical structure. A reaction shaft loading seat 11 is located at the top end of the reaction shaft 2, and the reaction shaft loading seat 11 is connected to the bottom of the loading shaft 101. The sidewalls of the arc-shaped pressure plates 4 are provided with straight-toothed edges 41, and adjacent sidewalls of two arc-shaped pressure plates 4 are engaged through the toothed edges 41. When the arc-shaped pressure plates 4 move in a direction perpendicular to the axis of the reaction shaft 2 and away from the reaction shaft 2, gaps will be generated between the toothed edges 41 of adjacent arc-shaped pressure plates 4. However, due to the presence of the straight-toothed edges 41, pressure can still be applied to the inner wall of the annular lining 5 even at the location where gaps occur, ensuring uniform and stable pressure.

[0033] like Figures 3 to 7 As shown, reaction shaft connecting plates 21 are evenly distributed on the side wall of reaction shaft 2 around its axis. The reaction shaft connecting plates 21 protrude along the surface of the side wall of reaction shaft 2, and their extension direction is parallel to the axis of reaction shaft 2. Arc-shaped pressure plate connecting plates 42 are evenly distributed on the inner wall of arc-shaped pressure plate 4 around its axis forming a cylindrical structure. The arc-shaped pressure plate connecting plates 42 protrude along the surface of the inner wall of arc-shaped pressure plate 4, and their extension direction is parallel to the axis of the cylindrical structure formed by the arc-shaped pressure plate 4. Subsequently, one end of connecting rod 3 is hinged to arc-shaped pressure plate connecting plate 42, and the other end of connecting rod 3 is hinged to reaction shaft connecting plate 21. Connecting rod 3 is also obliquely positioned to the horizontal plane. When the reaction shaft 2 moves upward under the action of the axial force loading platform 1, the reaction shaft connecting plate 21 moves upward as well. At this time, the connecting rod 3 causes the arc-shaped pressure plate connecting plate 42 and the arc-shaped pressure plate 4 to move towards the reaction shaft connecting plate 21, and the arc-shaped pressure plate 4 moves away from the annular lining 5. When the reaction shaft 2 moves downward under the action of the axial force loading platform 1, the reaction shaft connecting plate 21 moves downward as well. At this time, the connecting rod 3 causes the arc-shaped pressure plate connecting plate 42 and the arc-shaped pressure plate 4 to move away from the reaction shaft connecting plate 21, and the arc-shaped pressure plate 4 moves towards the annular lining 5. Finally, the arc-shaped pressure plate 4 presses against and applies pressure to the annular lining 5, allowing the annular lining 5 to bear the pressure. The contact process between the annular lining 5 and the arc-shaped pressure plate 4 diffuses the concentrated horizontal force into a surface load that is closer to the "internal pressure" effect, thereby approximately simulating the circumferential tensile stress and bending-tension coupling effect generated by the air pressure on the lining during cavern operation.

[0034] When conducting the first test on the annular lining 5, the equivalent internal pressure was first calibrated: several pressure sensors or contact stress measuring points were arranged along the circumferential and axial directions on the inner surface of the annular lining 5 sample. The arc-shaped pressure plate 4 was attached to the predetermined loading area on the inner surface of the annular lining 5. The vertical load of the axial force loading platform 1 was applied step by step using a small-amplitude graded loading method, and the axial force value and the contact pressure distribution on the inner surface were recorded simultaneously to establish the correspondence between "axial force and equivalent internal pressure". If necessary, the curvature of the arc-shaped pressure plate 4, the thickness of the pad 7, or the centering state of the connecting rod 3 were adjusted to make the contact pressure distribution more uniform and more in line with the target equivalent internal pressure characteristics.

[0035] During the formal test, the loading path was applied according to the preset working conditions: the applied axial force was monitored by the loading pressure sensor 12, and the vertical axial force was applied by the loading shaft 101 of the axial force loading platform 1 and transmitted to the reaction shaft 2. Under the geometric guidance and reaction constraint of the reaction shaft 2, the connecting rod 3, and the arc-shaped pressure plate 4, the vertical axial force was converted into a horizontal thrust. Finally, the horizontal thrust was stably transmitted to the arc-shaped pressure plate 4 through the connecting rod 3. The arc-shaped pressure plate 4 then applied the horizontal thrust as a surface load to the inner surface of the annular lining 5, thereby generating a circumferential tensile stress control state in the annular lining 5 that is similar to the internal pressure effect of the cavern. The loading process can adopt force control or displacement control methods, which can achieve monotonic loading to the target equivalent internal pressure, staged loading and maintaining stable load at each stage to observe the stable propagation of cracks, or multiple cyclic loading to simulate the pressure fluctuation effect caused by the cavern inflation and deflation conditions. The axial force, displacement, and equivalent internal pressure conversion values ​​were recorded during each loading / unloading stage.

[0036] For data acquisition and crack observation, when using the cushion layer 7 and steel sleeve 8 to simulate the surrounding rock, strain gauges only need to be placed on the inner and outer sides of the annular lining 5, and steel gauges need to be placed inside the annular lining 5 to obtain the stress-strain characteristics of the lining. When the surrounding rock is not considered, strain sensors, displacement gauges, or crack gauges can be placed on the outer surface of the annular lining 5. If necessary, crack observation marks can be preset at key observation points and combined with image / video recording to continuously observe the crack initiation location, propagation path, penetration time, and propagation rate of cracks on the outer surface of the annular lining 5. At the same time, combined with the load-displacement curve of the loading platform and the contact pressure data of the inner surface, the equivalent internal pressure of crack initiation, stiffness degradation, residual deformation, and crack evolution characteristics of the annular lining 5 under different working conditions can be obtained, realizing a rapid assessment of the mechanical response of the lining and the crack propagation mechanism.

[0037] After the test, the arc-shaped pressure plate 4 and connecting rod 3 can be unloaded and removed as needed, and the crack morphology of the annular lining 5 can be mapped or cut and observed to provide a basis for subsequent mechanism analysis and structural design parameter selection.

Claims

1. A pressurization device for testing the lining of an underground cavern with compressed air energy storage, characterized in that, include: At least two arc-shaped pressure plates (4) are used to form a cylindrical structure. The reaction shaft (2) is coaxial with the axis of the cylindrical structure and slides along the axis of the reaction shaft (2). The load conversion mechanism is connected to the reaction shaft (2) and the arc-shaped pressure plate (4) respectively; When the reaction shaft (2) slides along the axial direction of the reaction shaft (2), the load conversion mechanism drives the arc-shaped pressure plate (4) to slide along the axial direction perpendicular to the reaction shaft (2).

2. The pressurization device for the test lining of the underground cavern for compressed air energy storage as described in claim 1, characterized in that: The load conversion mechanism includes a connecting rod (3), which is obliquely arranged to the horizontal plane. One end of the connecting rod (3) is hinged to the reaction shaft (2), and the other end of the connecting rod (3) is hinged to the arc-shaped pressure plate (4).

3. The pressurization device for the test lining of the underground cavern for compressed air energy storage as described in claim 2, characterized in that: The connecting rod (3) is evenly distributed around the axis of the reaction force axis (2).

4. The pressurization device for testing the lining of an underground cavern with compressed air energy storage as described in any one of claims 1 to 3, characterized in that: The sidewall of the arc-shaped pressure plate (4) is provided with toothed edge (41), and the sidewalls of two adjacent arc-shaped pressure plates (4) are engaged by the toothed edge (41).

5. The pressurization device for testing the lining of an underground cavern with compressed air energy storage as described in any one of claims 1 to 3, characterized in that: It includes an axial force loading platform (1), the loading shaft (101) of the axial force loading platform (1) is connected to the reaction shaft (2), and the loading shaft (101) drives the reaction shaft (2) to slide along the axial direction of the reaction shaft (2).

6. The pressurization device for testing the lining of an underground cavern with compressed air energy storage as described in claim 5, characterized in that: The platform (9) is included. The axial force loading table (1) is fixedly connected to the platform (9) through the support rod (14). The support rod (14) is circumferentially distributed around the axis of the reaction force axis (2).

7. The pressurization device for the test lining of the underground cavern for compressed air energy storage as described in claim 5, characterized in that: Includes a controller (10), which is connected to the loading shaft (101) of the axial force loading table (1).

8. A pressurization structure for testing the lining of an underground cavern with compressed air energy storage, comprising the pressurization device for testing the lining of an underground cavern with compressed air energy storage as described in any one of claims 1 to 7, characterized in that: The ring lining (5) includes a cylindrical structure formed by the arc-shaped pressure plate (4) which is sleeved inside the ring lining (5). The load conversion mechanism drives the arc-shaped pressure plate (4) to slide toward the ring lining (5).

9. The pressurized test structure for compressed air storage underground cavern lining as described in claim 8, characterized in that: Includes a sleeve (8), which is fitted around the outer periphery of the annular lining (5).

10. The pressurized test structure for compressed air storage underground cavern lining as described in claim 9, characterized in that: Includes strain gauges disposed on the outer surface of the annular lining (5); and includes a steel bar gauge disposed inside the annular lining (5).

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