A force-heat flow coupling simulation test device of a pipeline layout type compressed air energy storage structure

Abstract

The application relates to the technical field of testing, and discloses a force-heat-flow coupling simulation test device for a pipeline layout type compressed air energy storage structure, which comprises a cylinder body, a left end sealing base, a right end sealing base, a rock sample limiter, a confining pressure sleeve, a left end sealing piston, a right end sealing piston, a gas storage pipe, a heat exchanger, a loading mechanism and the like. The test device can realize high-precision model construction of multiple physical field synergies, thereby simulating force-heat-flow coupling of the pipeline layout type compressed air energy storage structure in the whole energy storage period, and can realize multi-element information real-time collection of stress field distribution, displacement deformation, temperature gradient, gas pressure fluctuation and the like of the overall structure and the surrounding stratum environment based on controllable boundary conditions and material constitutive relations, so as to evaluate the gas storage capacity of the designed abandoned mine pipeline layout type compressed air energy storage structure under the force-heat-flow coupling state, and provide scientific guidance for the design of the compressed air energy storage structure.

Description

Technical Field

[0001] This invention relates to the field of testing technology, and in particular to a force-thermal-fluid coupling simulation test device for a pipeline-layout type compressed air energy storage structure. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] A major problem in the utilization of new energy sources is the difficulty in achieving a stable supply, resulting in intermittent characteristics and significant energy waste. Compressed air energy storage, as a novel energy storage system capable of peak shaving, effectively alleviates the intermittent nature of renewable energy generation, enhances the stability of energy supply transfer to the grid, and, with its low-carbon, environmentally friendly, clean, and efficient operating mechanism, has attracted widespread attention from the whole society, becoming an important research direction in the field of energy storage.

[0004] Compressed gas storage (CGS) in abandoned mines involves compressing gas and storing it within the mine's existing storage conditions. Compared to traditional CGS methods, CGS in abandoned mines eliminates the need for large-scale civil engineering projects, reducing construction time and complexity. Furthermore, my country has a vast number of undeveloped abandoned mines, allowing for the full utilization of goaf areas and tunnel interiors as storage space, resulting in greater storage capacity.

[0005] Currently, the main challenges in the renovation of abandoned mine roadways revolve around the stability of energy storage structures (CN117589493A), gas sealing (CN118347912A), and long-term operational durability (CN117705603A, CN115468855A). These challenges are mainly reflected in the following aspects: (1) Due to the impact of early mine excavation, the roadway has obvious damage zones. Under the cyclic load of high-pressure gas inside the compressed air energy storage cavern, the surrounding rock of the cavern faces the problem of instability and damage. (2) In the construction of traditional compressed air storage caverns, including abandoned mines, the sealing performance mainly relies on the sealing layer and the concrete sealing plug and the surrounding structure. At present, the failure mechanism of the cavern sealing performance in the above-mentioned locations is unclear. Under the periodic temperature and pressure action of high-pressure gas inside, the long-term operational stability is difficult to be effectively guaranteed, and the cavern faces the problem of gas leakage due to sealing failure.

[0006] Using pipelines laid in abandoned mines to construct compressed air energy storage can largely avoid structural failures caused by the above problems and ensure the efficient operation of the energy storage structure. However, there is currently a lack of an effective testing device to study the effectiveness of pipeline-laid compressed air energy storage technology. Summary of the Invention

[0007] To address the aforementioned problems, this invention proposes a mechanical-thermal-fluid coupling simulation test device for a pipeline-deployed compressed air energy storage structure, providing a research foundation and convenience for verifying simulation tests of compressed air energy storage technology using pipelines deployed in abandoned mines. Specifically, the technical solution of this invention is as follows.

[0008] A mechanical-thermal-fluid coupling simulation test device for a pipeline-layout type compressed air energy storage structure includes: a cylinder, a left-end sealing base, a right-end sealing base, a rock sample limiter, a confining pressure sleeve, a left-end sealing piston, a right-end sealing piston, a gas storage pipe, a heat exchanger, and a loading mechanism. The cylinder is horizontally positioned and has a cylindrical inner cavity. The left-end and right-end sealing bases cover the left and right ends of the cylinder and are detachably connected. The rock sample limiter is a T-shaped cylinder, adjacent to the left-end sealing base and located on the right side. The thinner end of the rock sample limiter passes through the left-end sealing base, and there is a gap between the outer wall of the thicker end of the rock sample limiter and the inner wall of the cylinder. The flexible confining pressure sleeve is located within the inner cavity of the cylinder, and its two ends are tightly fitted onto the outer wall of the thicker end of the rock sample limiter and the outer wall of the right-end sealing base, respectively, forming a confining pressure chamber between the confining pressure sleeve and the cylinder for filling with gas to create confining pressure. The left and right sealing pistons are respectively sealed and confined within the mounting holes of the rock sample limiter and the right sealing base. The gas storage tube is located within the confining sleeve, with both ends sealed onto the end steps of the left and right sealing pistons, respectively. The space between the gas storage tube and the confining sleeve forms a sample mounting chamber. The right sealing piston has an inflation pipe communicating with the inner cavity of the gas storage tube. The heat exchanger is located within the gas storage tube, and the loading mechanism is mounted on the outer wall of the right sealing base to apply a load to the filling material in the sample mounting chamber.

[0009] Furthermore, an adjusting rod is threadedly connected to the left-end sealing base, one end of which passes through the left-end sealing base and abuts against the side wall of the thicker end of the rock sample limiter. The other end of the adjusting rod is located outside the left-end sealing base. Preferably, an unlocking gap is reserved between the left side wall of the thicker end of the left-end sealing piston and the rock sample limiter.

[0010] Further, the loading mechanism includes: a reaction frame, a screw, a force transmission plate, a force transmission rod, and a constraint loading end. Specifically: the reaction frame is fixed to the outer wall of the right-end sealing base; one end of the screw passes through the reaction frame and is fixedly connected to the force transmission plate, with a threaded connection between the screw and the reaction frame; one end of the force transmission rod is connected to the force transmission plate, and the other end movably passes through the right-end sealing base and connects to the constraint loading end, which is an annular body that fits onto the gas storage pipe, and the two are slidably sealed together. Preferably, the right end of the constraint loading end is located in the mounting hole on the left end face of the right-end sealing base, thereby increasing the space of the sample mounting chamber.

[0011] Furthermore, the mounting hole of the right-end sealing base is a horizontally arranged T-shaped hole, with the narrower end of the T-shaped hole located on the outer side. The right-end sealing piston is located in the T-shaped hole, and the right-end sealing piston is a T-shaped cylinder corresponding to the T-shaped hole. The constraint loading end is simultaneously fitted onto the outer wall of both the gas storage pipe and the right-end sealing piston. Preferably, a sealing ring disposed in a sealing groove is provided between the constraint loading end and the right-end sealing piston, as well as the side wall of the T-shaped hole.

[0012] Furthermore, it also includes a tapered sleeve, which is a T-shaped sleeve, and the outer side wall of the narrower end of the sleeve is a tapered surface. This tapered sleeve is fitted onto the rock sample limiter and is disposed adjacent to the inner wall of the left-end sealing base. The outer side wall of the tapered sleeve is sealingly connected to the inner side wall of the cylinder. Preferably, a sealing ring disposed in a sealing groove is provided between the tapered sleeve and the inner side wall of the cylinder.

[0013] Furthermore, both ends of the confining sleeve are outwardly opening conical openings, which fit tightly onto the conical surface of the tapered sleeve.

[0014] Furthermore, the mounting hole of the rock sample limiter is a T-shaped hole, with the narrower end of the T-shaped hole located on the outer side. The left-end sealing piston is a T-shaped cylinder located in the T-shaped hole and corresponding to it. Preferably, a sealing ring is provided between the left-end sealing piston and the T-shaped hole, which is disposed in a sealing groove.

[0015] Furthermore, the thinner ends of the left and right sealing pistons are threadedly connected to their respective T-shaped holes.

[0016] Furthermore, the outer wall of the cylinder has a confining pressure inflation port and a confining pressure monitoring element mounting port.

[0017] Furthermore, the rock sample limiter is provided with a first information acquisition channel, one end of which is connected to the sample mounting chamber and the other end of which is connected to the outside. A second information acquisition channel is provided at the center of the left-end sealing piston, one end of which is connected to the gas storage pipe and the other end of which is connected to the outside.

[0018] Furthermore, the heat exchanger forms a circulation pipeline with an external heat exchange medium tank through a medium channel on the right-end sealed piston. A drive pump and a temperature detection instrument are installed on this pipeline to drive the circulation of the heat exchange medium within the heat exchanger and simultaneously test the temperature of the discharged heat exchange medium. Optionally, the heat exchanger is a spiral pipe.

[0019] Furthermore, during testing, the sample mounting chamber contains a cylindrical surrounding rock sample, the outer wall of which is fitted against the confining sleeve. The space between the surrounding rock sample and the gas storage pipe is filled with a filling material.

[0020] Furthermore, the end step of the left-end sealing piston is a conical head, and an annular sealing sleeve is fitted onto this conical head to form a cylindrical end step. The left port of the gas storage tube is fitted onto this cylindrical end step, and the inner wall of the gas storage tube is in close contact with the annular sealing sleeve, with the end of the gas storage tube abutting against the step surface of the end step. The structure of the right-end sealing piston is the same as that of the left-end sealing piston, and the connection method between the right-end sealing piston and the right port of the gas storage tube is the same as the connection method between the left-end sealing piston and the left port of the gas storage tube.

[0021] Compared with the prior art, the present invention has at least the following beneficial technical effects: The experimental device of the present invention can realize the construction of a high-precision model of the synergistic effect of multiple physical fields, thereby simulating the force-thermal-fluid coupling of the pipeline-deployed compressed air energy storage structure throughout the entire energy storage cycle. It can also collect multi-dimensional information in real time on parameters such as stress field distribution, displacement deformation, temperature gradient, and air pressure fluctuation of the overall structure and the surrounding geological environment based on controllable boundary conditions and material constitutive relations, thereby evaluating the gas storage capacity of the designed abandoned mine pipeline-deployed compressed air energy storage structure under the force-thermal-fluid coupling state, and providing scientific guidance for the design of compressed air energy storage structures. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 The following is a perspective view of the simulation test apparatus in the embodiments.

[0024] Figure 2 The following is a cross-sectional view of the simulation test apparatus in the embodiments.

[0025] Figure 3 The following is a schematic diagram of the structure of the left-end sealing piston in the embodiment below.

[0026] Figure 4 The following is a schematic diagram of the tapered sleeve in the embodiments.

[0027] Figure 5 This is a cross-sectional view of another simulation test apparatus in the following embodiments.

[0028] Figure 6 This is a schematic diagram of another left-end sealing piston in the following embodiments.

[0029] Figure 7 The following is a schematic diagram of the structure of the annular sealing sleeve in the embodiments below.

[0030] The markings in the above figures represent: 1-cylinder body, 2-left end sealing base, 3-right end sealing base, 4-rock sample limiter, 5-containment sleeve, 6-left end sealing piston, 7-right end sealing piston, 8-gas storage pipe, 9-heat exchanger, 10-reaction frame, 11-screw, 12-force transmission plate, 13-force transmission rod, 14-constraint loading end, 15-sealing ring, 16-tapered sleeve, 201-adjusting rod, 401-unlocking gap, 402-first information acquisition channel, 501-containment chamber, 502-containment inflation port, 503-containment monitoring element installation port, 504-conical opening, 505-surrounding rock sample, 601-end step, 602-second information acquisition channel, 603-annular sealing sleeve, 701-inflation pipe, 702-medium channel. Detailed Implementation

[0031] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves. They do not limit the structure and are merely for the purpose of facilitating the description of this invention and simplifying the description. They do not indicate or imply that the device or component referred to needs to have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] The mechanical-thermal-fluid coupling simulation test device for the pipeline-layout type compressed air energy storage structure of the present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0035] refer to Figure 1 , Figure 2 and Figure 3 Example of a force-thermal-fluid coupling simulation test device for a pipeline-layout type compressed air energy storage structure, comprising: a cylinder 1, a left-end sealing base 2, a right-end sealing base 3, a rock sample limiter 4, a confining pressure sleeve 5, a left-end sealing piston 6, a right-end sealing piston 7, a gas storage pipe 8, a heat exchanger 9, and a loading mechanism. Specifically: the cylinder 1 is a cylindrical body open at both ends, horizontally arranged, and has a cylindrical inner cavity. The left-end sealing base 2 covers the left port of the cylinder 1, and the two are detachably connected by bolts. The right-end sealing base 3 is a T-shaped cylinder, with its thinner end located in the right port of the cylinder 1 with a gap between them, and its thicker end covering the right port of the cylinder 1, and the two are detachably connected by bolts.

[0036] The rock sample limiter 4 is a T-shaped cylinder integrally formed from a thicker end and a thinner end, with the thicker end adjacent to the right side of the left end sealing base 2. The thinner end passes through a through hole in the left end sealing base 2 and is flush with the outer wall of the left end sealing base 2. There is a gap between the outer wall of the thicker end of the rock sample limiter 4 and the inner wall of the cylinder 1 to accommodate the end of the confining sleeve 5.

[0037] The confining pressure sleeve 5 is a cylindrical body made of flexible material such as rubber. It is disposed in the inner cavity of the cylinder 1, and the left end of the confining pressure sleeve 5 is tightly fitted onto the outer wall of the thicker end of the rock sample limiter 4. The right end of the confining pressure sleeve 5 is tightly fitted onto the outer wall of the thinner end of the right end sealing base 3. There is a space between the confining pressure sleeve 5 and the cylinder 1, which serves as a confining pressure chamber 501 for filling with air to form confining pressure applied to the side wall of the confining pressure sleeve 5. For this purpose, the outer wall of the cylinder 1 has a confining pressure inflation port 502 and a confining pressure monitoring element mounting port 503 communicating with the confining pressure chamber 501. Wherein: after the confining pressure inflation port 502 is connected to an external inflation device, gas can be filled into the confining pressure chamber 501 to form pressure on the confining pressure sleeve 5, thereby simulating the confining pressure exerted by the rock mass on the roadway in an abandoned mine. The confining pressure monitoring element mounting port 503 is used to install pressure detection elements such as pressure detection sensors to monitor the pressure in the confining pressure chamber 501 and ensure that the confining pressure is maintained at a set value.

[0038] The left-end sealing piston 6 and the right-end sealing piston 7 are respectively sealed and confined in the mounting holes of the rock sample limiter 4 and the right-end sealing base 3. Specifically, the mounting hole on the rock sample limiter 4 is a horizontally arranged T-shaped hole, with its narrower end located on the outside. The left-end sealing piston 6 is a T-shaped cylinder located in the T-shaped hole and corresponding to it. A sealing ring 15 is provided in the sealing groove between the left-end sealing piston 6 and the T-shaped hole, thereby improving the sealing performance between the two. Similarly, the mounting hole on the right-end sealing base 3 is also a horizontally arranged T-shaped hole, with its narrower end located on the outside. The right-end sealing piston 7 is a T-shaped cylinder located in the T-shaped hole and corresponding to it. A sealing ring 15 is provided in the sealing groove between the right-end sealing piston 7 and its T-shaped hole, thereby improving the sealing performance between the two and preventing air leakage from affecting the accuracy of the test results. The narrower ends of the left-end sealing piston 6 and the right-end sealing piston 7 are threadedly connected to their respective T-shaped holes.

[0039] The gas storage pipe 8 is a rigid straight pipe (such as a steel pipe, copper pipe, etc.) and is installed in the confining sleeve 5. Both ends of the gas storage pipe 8 are respectively sealed and fitted onto the end steps 601 of the left-end sealing piston 6 and the right-end sealing piston 7, with the end face of the gas storage pipe 8 abutting against the step surface of the end step 601. The space between the gas storage pipe 8 and the confining sleeve 5 forms a sample mounting chamber for mounting the surrounding rock sample 505 and granular filling material. The right-end sealing piston 7 has an inflation pipe 701 communicating with the inner cavity of the gas storage pipe 8 to fill it with compressed gas and construct a compressed air energy storage condition. The right-end sealing base 3 and the rock sample limiter 4 can seal both ends of the surrounding rock sample 505, thereby enhancing the durability of the confining sleeve 5 at the interface between the rock sample limiter 4 and the surrounding rock sample 505. This prevents the confining sleeve 5 from being subjected to shear force caused by confining pressure at the gap due to excessively large interface gaps, which could lead to the confining sleeve 5 being prone to breakage at the gap.

[0040] The heat exchanger 9 is a spiral pipe installed in the gas storage pipe 8. Its two ends are connected to two medium channels 702 on the right-end sealing piston 7. The medium channels 702 form a circulation pipeline with the external heat exchange medium tank. A drive pump and a temperature detection instrument are installed on the pipeline to drive the heat exchange medium (such as water) in the heat exchanger 9 to circulate. At the same time, the temperature of the discharged heat exchange medium is tested to obtain the change of the heat of the compressed air in the gas storage pipe 8.

[0041] The loading mechanism includes a reaction frame 10, a screw 11, a force transmission plate 12, a force transmission rod 13, and a constraint loading end 14. The reaction frame 10 is a U-shaped structure, with both ends fixed to the outer wall of the right-end sealing base 3 by bolts or other fasteners. One end of the screw 11 passes through the reaction frame 10 and is fixedly connected to the force transmission plate 12 located within the reaction frame 10, with a threaded connection between the screw 11 and the reaction frame 10. One end of the force transmission rod 13 is connected to the force transmission plate 12, and the other end movably passes through the right-end sealing base 3 and connects to the constraint loading end 14. The constraint loading end 14 is an annular body that slides on the gas storage pipe 8, with a sealing ring 15 set in a groove between them to prevent air leakage from the gas storage pipe 8, achieving a sliding seal connection. Several force transmission rods 13 are evenly distributed circumferentially along the constraint loading end 14 to apply pressure to the filling material more evenly. The constraint loading end 14, fitted onto the gas storage pipe 8, serves to constrain and protect its right end, ensuring balance between the left and right ends of the gas storage pipe 8. This prevents expansion of the gas storage pipe 8 end under high gas pressure, thus avoiding leakage. This is because the left end of the gas storage pipe 8 is located within the rock sample limiter 4, which rigidly constrains it, preventing expansion and deformation due to internal gas pressure. Without the constraint loading end 14, the right end of the gas storage pipe 8 becomes a weak load-bearing end, more susceptible to pressure breaches, leading to expansion and leakage, and consequently, decreased accuracy of the test results.

[0042] In another implementation, refer to Figure 2 The left-end sealing base 2 of the test device in the above embodiment has a through screw hole, through which an adjusting rod 201 is threadedly connected. One end of the adjusting rod 201 passes through the left-end sealing base 2 and abuts against the side wall of the thicker end of the rock sample limiter 4. The other end of the adjusting rod 201 is located outside the left-end sealing base 2. Several adjusting rods 201 are evenly distributed along the circumference of the left-end sealing base 2. By adjusting the adjusting rod 201, the right end face of the rock sample limiter 4 can be pressed tightly against the surrounding rock sample 505, ensuring a tighter connection between the two. This helps to avoid the confining sleeve 5 being subjected to shear force caused by confining pressure at the gap due to excessive gaps at the interface, which would make the confining sleeve 5 more prone to breakage at the gap.

[0043] A better implementation method based on this is: (Refer to...) Figure 2An unlocking gap 401 is provided between the left side wall of the thicker end of the left-end sealing piston 6 and the rock sample limiter 4. That is, when the assembly is completed and the end face of the gas storage tube 8 is pressed against the step surface of the end step 601 of the left-end sealing piston 6, the left side wall of the thicker end of the left-end sealing piston 6 and the rock sample limiter 4 are not in contact, but have the unlocking gap 401. Thus, before it is necessary to screw in the adjusting rod 201 to press the right end face of the rock sample limiter 4 against the end face of the surrounding rock sample 505, the left-end sealing piston 6 is first rotated outward / to the left a certain distance (at this time, the unlocking gap 401 is reduced or even disappeared), and then the adjusting rod 201 is screwed in. At this time, the left-end sealing piston 6 moves synchronously with the rock sample limiter 4. The above setting avoids the problem that when the rock sample limiter 4 needs to move to the right, the left-end sealing piston 6 is constrained by the gas storage tube 8, which prevents the rock sample limiter 4 from moving to the right. This is because of the existence of the unlocking gap 401. The left sealing piston 6 can be adjusted outward to temporarily disengage / unlock its end step 601 from the end of the gas storage pipe 8, thus eliminating the restriction on the rock sample limiter 4. After adjusting the rock sample limiter 4, the left sealing piston 6 can be rotated inward / to the right again until its end step 601 is once again pressed against the end of the gas storage pipe 8, achieving a sealed connection.

[0044] In another implementation, refer to Figure 2 The test apparatus of the above embodiment also includes a tapered sleeve 16. Specifically, refer to... Figure 4 The tapered sleeve 16 is a T-shaped sleeve, and the outer wall of the narrower end of the sleeve is a conical surface. Two tapered sleeves 16 are respectively fitted onto the rock sample limiter 4 and the right-end sealing base 3. One tapered sleeve 16 at the left end is positioned adjacent to the inner wall of the left-end sealing base 2, and the other tapered sleeve 16 at the right end is positioned adjacent to the inner wall of the wider end of the right-end sealing base 3. The outer walls of both tapered sleeves 16 are connected to the inner wall of the cylinder 1 by sealing rings 15 located in the sealing groove, ensuring good sealing of the confining pressure chamber 501. Simultaneously, both ends of the confining pressure sleeve 5 are outwardly opening conical openings 504, which fit tightly onto the conical surfaces of the tapered sleeves 16. This structure transforms the simple connection between the confining sleeve 5, the rock sample limiter 4, and the right-end sealing base 3 into a more complex mechanical interlocking structure. Under the confining pressure in the confining sleeve 5, both ends of the confining sleeve 5 are tightly pressed against the conical surface of the tapered sleeve 16, forming a more complex and varied gas leakage channel, thus better preventing gas leakage.

[0045] In another implementation, refer to Figure 2In the above embodiment, the right end of the constraint loading end 14 of the test device is located in the T-shaped mounting hole on the left end face of the right end sealing base 3. At this time, the constraint loading end 14 is simultaneously fitted onto the right end sealing piston 7 and the gas storage tube 8, and the interface seam between the two is wrapped by the constraint loading end 14. This not only further prevents the gas storage tube 8 from leaking, avoiding affecting the accuracy of the test results, but also allows for a larger space in the sample mounting chamber, filling more filling material and constructing a more complete and comprehensive pipeline protection zone. Furthermore, a sealing ring 15 is provided in the sealing groove between the constraint loading end 14 and the right end sealing piston 7 and the side wall of the T-shaped hole.

[0046] In another implementation, refer to Figure 5 , Figure 6 and Figure 7 In the above embodiment, the end step 601 of the left-end sealing piston 6 of the experimental device is a conical head, and an annular sealing sleeve 603 is fitted onto the conical head to form a cylindrical end step. The left port of the gas storage pipe 8 is fitted onto the cylindrical end step, and the inner wall of the gas storage pipe 8 is in close contact with the annular sealing sleeve 603. The end of the gas storage pipe 8 abuts against the step surface of the end step 601. Similarly, the structure of the right-end sealing piston 7 is the same as that of the left-end sealing piston 6, and the connection method between the right-end sealing piston 7 and the right port of the gas storage pipe 8 is the same as the connection method between the left-end sealing piston 6 and the left port of the gas storage pipe 8. The structure of this embodiment can utilize the pressure applied to the annular sealing sleeve 603 by the compressed air in the gas storage pipe 8 (e.g., Figure 5 , Figure 6 As indicated by the middle arrow, the annular sealing sleeve 603 slides outward along the conical surface of the end step 601. Under the constraint of the triangular space formed by the conical surface and the inner wall of the gas storage pipe 8, the deformation volume of the annular sealing sleeve 603 increases, further improving the seal between the gas storage pipe 8 and the left end sealing piston 6.

[0047] The test apparatus described in the above embodiment is for an energy storage structure consisting of a pipeline for storing compressed air installed in an abandoned mine, with granular filling material filling the pipeline. The filling material forms a pipeline protection zone around the gas storage pipe 8 to test the protective effect of the protection zone on the gas storage pipe 8 under surrounding rock stress. During the force-thermal-fluid coupling simulation test of this energy storage structure, a cylindrical surrounding rock sample 505 is first inserted into the confining pressure sleeve 5 / sample mounting chamber from the left port of the cylinder 1, at which point the outer wall of the surrounding rock sample 505 is tightly fitted to the confining pressure sleeve 5. After completion, the space between the inner wall of the surrounding rock sample 505 and the gas storage pipe 8 is filled with granular filling material (e.g., a mixture of rigid particles such as sand, ore, and steel slag and flexible particles such as rubber and plastic, or rigid particles coated with flexible materials, etc.). The surrounding rock sample 505 is collected from the abandoned mine. After the above installation is completed, the left-end sealing piston 6 is installed on the rock sample limiter 4, and then the rock sample limiter 4 and the left-end sealing base 2 are installed sequentially on the left port of the cylinder body 1.

[0048] (1) Gas is injected into the confining pressure chamber 501 through the confining pressure inlet 502 to form confining pressure on the surrounding rock sample 505, thereby reproducing the pressure on the surrounding rock in the roadway and realizing the construction of the confining pressure state of the internal structural strata of the abandoned mine, making the test closer to the actual engineering. The confining pressure can be obtained by on-site testing of the abandoned mine. By changing the pressure of the injected gas, the purpose of applying precise stress boundary conditions to the surrounding rock sample 505 can be achieved. During this process, the pressure in the confining pressure chamber 501 is monitored by the pressure detection sensor installed in the confining pressure monitoring element installation port 503 to ensure that the confining pressure is maintained at the set value. The temperature and stress changes of the inner surface of the surrounding rock sample 505 are tested by temperature sensors (such as adhesive K-type thermocouples) and stress sensors (such as adhesive resistive stress sensors) installed on the inner surface of the surrounding rock sample 505. The temperature changes on the inner surface can be used to assess the heat loss caused by the surrounding rock sample 505 (corresponding to an abandoned mine shaft used for installing compressed air pipelines in actual engineering). The temperature data can also guide heat recovery (such as waste heat utilization) or auxiliary heating to improve energy efficiency. The stress changes can be used to assess the stability and durability of the pipeline; the less easily it deforms under the applied confining pressure, the better its stability and durability.

[0049] (2) Rotating the screw 11 drives the constraint loading end 14 to move and apply pressure to the filling material, thereby achieving the purpose of applying controllable displacement boundary conditions to the filling material, thus accurately simulating the complex boundary conditions and various load combinations of the pipeline-type compressed gas storage structure under actual working conditions. During the above test, the rock sample limiter 4 is equipped with a first information acquisition channel 402, one end of which is connected to the sample installation chamber, and the other end is connected to the outside. Temperature sensors and stress sensors are arranged along the length of the filling material to collect temperature and stress changes. Among them, the collected temperature changes can be used to evaluate the thermal insulation performance of the filling material on the gas storage pipe 8 and the stress adjustment effect of the filling material on the internal pipe.

[0050] (3) Connect the inflation pipe 701 to the external air device, and fill the air storage pipe 8 with compressed air after opening the valve. A second information acquisition channel 602 is provided through the center of the left end sealing piston 6, which is connected to the air storage pipe 8 and the other end is connected to the outside. At the same time, heat exchange medium is introduced into the heat exchanger 9 through the medium channel 702, and the temperature of the discharged heat exchange medium is tested in order to obtain the change of heat of compressed air in the air storage pipe 8. Temperature sensors can be installed at the middle and end positions of the inner surface of the air storage pipe 8 to measure the temperature, and temperature sensors can be installed on the outer surface of the air storage pipe 8 to monitor the temperature change. The air pressure change inside the air storage pipe 8 is measured by the air pressure sensor connected to the inflation pipe 701, and the obtained temperature and air pressure change data can be used to evaluate the heat loss of the air storage pipe 8. The deformation of the air storage pipe is monitored by the strain gauge set on the outer wall of the air storage pipe 8, thereby evaluating the stability performance of the air storage pipe 8.

[0051] (4) Release the compressed air in the storage pipe 8 through the inflation pipe 701 and collect the change in air pressure in the storage pipe 8 at a predetermined deflation rate. Finally, based on the data and change curves collected in the above steps, analyze the temperature and pressure change patterns under different working conditions under the force-heat-fluid coupling effect to evaluate the capability of the pipeline-laid compressed air energy storage structure.

[0052] Finally, it should be noted that any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention. Although specific embodiments of this invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this invention are still within the scope of protection of this invention.

Claims

1. A mechanical-thermal-fluid coupling simulation test device for a pipeline-layout type compressed air energy storage structure, characterized in that, include: The cylinder body is horizontally positioned and has a cylindrical inner cavity; The left and right sealing bases cover the left and right ports of the cylinder body respectively and are detachably connected. The rock sample limiter is a T-shaped cylinder, which is adjacent to the left-end sealing base and located on its right side; The thinner end of the rock sample limiter passes through the left end sealing base, and there is a gap between the outer wall of the thicker end of the rock sample limiter and the inner wall of the cylinder. A confining sleeve, which is flexible, is located in the inner cavity of the cylinder body, and both ends of the confining sleeve are tightly fitted onto the outer wall of the thicker end of the rock sample limiter and the outer wall of the right end sealing base, respectively, forming a confining cavity between the confining sleeve and the cylinder body. The left-end sealing piston and the right-end sealing piston respectively seal and limit the installation holes of the rock sample limiter and the right-end sealing base; A gas storage tube is located in the confining pressure sleeve, and both ends of the gas storage tube are respectively sealed on the end steps of the left and right sealing pistons; the space between the gas storage tube and the confining pressure sleeve forms a sample mounting chamber; the right sealing piston has an inflation pipe communicating with the inner cavity of the gas storage tube; the gas storage tube is equipped with a heat exchanger. A loading mechanism, mounted on the outer wall of the right-end sealing base, is used to apply a load to the filling material in the sample mounting chamber.

2. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, An adjusting rod is threaded onto the left end sealing base. One end of the adjusting rod passes through the left end sealing base and abuts against the side wall of the thicker end of the rock sample limiter. The other end of the adjusting rod is located outside the left end sealing base. Alternatively, an unlocking gap may be provided between the left side wall of the thicker end of the left-end sealing piston and the rock sample limiter.

3. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, The loading mechanism includes: a reaction frame, a screw, a force transmission plate, a force transmission rod, and a constraint loading end; wherein: the reaction frame is fixed on the outer wall of the right end sealing base; one end of the screw passes through the reaction frame and is fixedly connected to the force transmission plate, and the screw and the reaction frame are threaded together; one end of the force transmission rod is connected to the force transmission plate, and the other end movably passes through the right end sealing base and is connected to the constraint loading end, which is an annular body that is fitted on the gas storage pipe and the two are slidably sealed together; or, the right end of the constraint loading end is located in the mounting hole on the left end face of the right end sealing base.

4. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 3, characterized in that, The mounting hole is a horizontally arranged T-shaped hole, with the narrower end of the T-shaped hole located on the outer side; the right-end sealing piston is located in the T-shaped hole, and the right-end sealing piston is a T-shaped cylinder corresponding to the T-shaped hole; the constraint loading end is simultaneously fitted onto the outer wall of the gas storage pipe and the right-end sealing piston; or, the constraint loading end has a sealing ring set in the sealing groove between the right-end sealing piston and the side wall of the T-shaped hole.

5. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, It also includes a tapered sleeve, which is a T-shaped sleeve, and the outer side wall of the narrower end of the sleeve is a tapered surface; the tapered sleeve is fitted on the rock sample limiter and is disposed close to the inner wall of the left end sealing base, and the outer side wall of the tapered sleeve is sealed to the inner side wall of the cylinder. Alternatively, a sealing ring disposed in a sealing groove is provided between the tapered sleeve and the inner wall of the cylinder; Alternatively, both ends of the confining sleeve are outwardly flared conical openings, which fit tightly onto the conical surface of the tapered sleeve.

6. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, The mounting hole of the rock sample limiter is a T-shaped hole, with the narrower end of the T-shaped hole located on the outside; the left-end sealing piston is a T-shaped cylinder located in the T-shaped hole and corresponding to it; or, the left-end sealing piston and the T-shaped hole have a sealing ring disposed in a sealing groove.

7. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, The thinner ends of the left and right sealing pistons are threadedly connected to their respective T-shaped holes.

8. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, The outer wall of the cylinder has a confining pressure inflation port and a confining pressure monitoring element mounting port; Alternatively, the rock sample limiter is provided with a first information acquisition channel, one end of which is connected to the sample installation chamber and the other end is connected to the outside. Alternatively, a second information acquisition channel may be provided at the center of the left-end sealing piston, with one end connected to the gas storage pipe and the other end connected to the outside.

9. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to claim 1, characterized in that, The heat exchanger forms a circulation pipeline with the external heat exchange medium tank through the medium channel on the right-end sealed piston. The pipeline is equipped with a drive pump and a temperature detection instrument to drive the heat exchange medium in the heat exchanger to circulate and at the same time test the temperature of the discharged heat exchange medium; or, the heat exchanger is a spiral pipeline.

10. The force-thermal-fluid coupling simulation test device for pipeline-layout compressed air energy storage structure according to any one of claims 1-9, characterized in that, The end step of the left sealing piston is a conical head, and an annular sealing sleeve is fitted onto the conical head to form a cylindrical end step; the left port of the gas storage tube is fitted onto the cylindrical end step, and the inner wall of the gas storage tube is in close contact with the annular sealing sleeve, and the end of the gas storage tube abuts against the step surface of the end step; the structure of the right sealing piston is the same as that of the left sealing piston, and the connection method between the right sealing piston and the right port of the gas storage tube is the same as the connection method between the left sealing piston and the left port of the gas storage tube.

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