Hydrogen diffusion test apparatus

Abstract

The embodiment of the application provides a hydrogen diffusion experiment device, and relates to the technical field of hydrogen storage. The hydrogen diffusion experiment device comprises: a core holder, the inside of the core holder is provided with a first diffusion chamber, a sample chamber and a second diffusion chamber, the first diffusion chamber and the second diffusion chamber are respectively arranged on the opposite sides of the sample chamber, and the sample chamber is used for accommodating a geological sample; a hydrogen supply mechanism connected with the second diffusion chamber; a first gas supply mechanism connected with the first diffusion chamber; and a detection mechanism connected with the first diffusion chamber and the second diffusion chamber, and used for detecting the gas concentration in the first diffusion chamber and the second diffusion chamber. The hydrogen diffusion experiment device can replace different geological samples in the core holder, carry out an experiment on the hydrogen diffusion characteristics in a room, and obtain key parameters such as diffusion coefficients under different geological structures, gas concentrations and temperature and pressure conditions, so as to provide reliable data support for hydrogen storage library site selection.

Description

Technical Field

[0001] This application relates to the field of hydrogen storage technology, and in particular to a hydrogen diffusion experimental device. Background Technology

[0002] Hydrogen energy is a secondary energy source produced by converting primary energy sources such as solar, wind, hydro, and fossil fuels. It is widely used in industrial fuels, hydrogen fuel cell power, distributed power generation, and large-scale long-term energy storage.

[0003] In related technologies, hydrogen exists in gaseous form at normal temperature and pressure. Due to its low density and flammability, hydrogen is prone to explosion and requires storage in existing geological structures that offer high safety, low cost, and large capacity. These existing geological structures include depleted oil and gas reservoirs, salt caverns, deep aquifers, and tight reservoirs. Through on-site geological sampling, in-situ testing, and on-site gas injection and sealing tests, relevant parameters such as lithology, mechanical properties, permeability characteristics, and sealing performance of different types of geological structures are obtained and determined. Based on these parameters, different geological models are constructed for numerical simulation to analyze the storage capacity and sealing performance of different types of geological structures. This allows for the identification of target geological structures with large storage space and strong sealing performance, thereby completing the site selection for hydrogen storage facilities.

[0004] However, conducting field tests on different types of geological structures and constructing different geological models based on relevant parameters of different types of geological structures for numerical simulation reduces the efficiency of hydrogen storage site selection. Summary of the Invention

[0005] This application provides a hydrogen diffusion experimental device that conducts field tests on different types of geological structures and constructs different geological models based on relevant parameters of different types of geological structures for numerical simulation, in order to solve the problem of reduced efficiency in hydrogen storage site selection.

[0006] In a first aspect, embodiments of this application provide a hydrogen diffusion experimental apparatus, comprising:

[0007] A core holder, the core holder having a first diffusion chamber, a sample chamber and a second diffusion chamber inside, the first diffusion chamber and the second diffusion chamber being respectively located on opposite sides of the sample chamber, the sample chamber being used to hold geological samples;

[0008] A hydrogen supply mechanism is connected to the second diffusion chamber and is used to deliver hydrogen to the second diffusion chamber under a first preset pressure.

[0009] A first gas supply mechanism is connected to the first diffusion chamber and is used to deliver gas to the first diffusion chamber under a second preset pressure.

[0010] The detection mechanism is connected to both the first diffusion chamber and the second diffusion chamber, and is used to detect the gas concentration in the first diffusion chamber and the second diffusion chamber.

[0011] In some embodiments, the hydrogen supply mechanism includes a hydrogen storage component and a gas delivery component. The gas delivery component is connected between the hydrogen storage component and the second diffusion chamber. The hydrogen storage component is used to store hydrogen gas, and the gas delivery component is used to deliver the hydrogen gas stored in the hydrogen storage component to the second diffusion chamber at the first preset pressure.

[0012] In some embodiments, the first gas supply mechanism includes a first gas storage component and a first conveying component. The first conveying component is connected between the first gas storage component and the first diffusion chamber. The first gas storage component is used to store gas, and the first conveying component is used to convey the gas stored in the first gas storage component to the first diffusion chamber under the second preset pressure.

[0013] In some embodiments, the system further includes a second gas supply mechanism and a conveying mechanism. The second gas supply mechanism is connected to the conveying mechanism, and the conveying mechanism is connected to the second diffusion chamber. The second gas supply mechanism is used to convey gas to the conveying mechanism at a third preset pressure. The hydrogen supply mechanism is used to convey hydrogen to the conveying mechanism or the second diffusion chamber at a first preset pressure. The conveying mechanism is used to mix the gas from the second gas supply mechanism and the hydrogen from the hydrogen supply mechanism and convey them to the second diffusion chamber.

[0014] In some embodiments, the second gas supply mechanism includes a second gas storage component and a second conveying component. The second conveying component is connected between the second gas storage component and the conveying mechanism. The second gas storage component is used to store gas, and the second conveying component is used to convey the gas stored in the second gas storage component to the conveying mechanism under the third preset pressure.

[0015] In some embodiments, a pressure balancing mechanism is further included, which is connected between the first diffusion chamber and the second diffusion chamber, and is used to adjust the pressure in the first diffusion chamber and the second diffusion chamber to be equal.

[0016] In some embodiments, the pressure balancing mechanism includes a cylinder and a balancing piston, one end of the cylinder is connected to the first diffusion chamber, the other end of the cylinder is connected to the second diffusion chamber, and the balancing piston is slidably connected to the cylinder.

[0017] In some embodiments, a pressure stabilizing mechanism is further included, which is connected to the hydrogen supply mechanism, the first gas supply mechanism, and the second gas supply mechanism. The pressure stabilizing mechanism is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism, the first gas supply mechanism, and the second gas supply mechanism, such that the hydrogen pressure inside the hydrogen supply mechanism is the first preset pressure, the gas pressure inside the first gas supply mechanism is the second preset pressure, and the gas pressure inside the second gas supply mechanism is the third preset pressure.

[0018] In some embodiments, the pressure stabilizing mechanism includes an opening / closing element and a constant pressure element. The opening / closing element is connected to the hydrogen supply mechanism, the first gas supply mechanism, and the second gas supply mechanism. The constant pressure element is connected to the opening / closing element. The opening / closing element is used to connect at least one of the hydrogen supply mechanism, the first gas supply mechanism, and the second gas supply mechanism with the constant pressure element. The constant pressure element is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism, the first gas supply mechanism, and the second gas supply mechanism through the opening / closing element.

[0019] In some embodiments, a vacuuming mechanism and a pressure simulation mechanism are also included. The vacuuming mechanism is connected to the core holder and is used to evacuate the core holder to bring it into a vacuum state. The pressure simulation mechanism is connected to the core holder and is used to apply pressure to the geological sample inside the core holder.

[0020] This application provides a hydrogen diffusion experimental device. The device simulates the hydrogen concentration-driven diffusion process in the geological sample by placing a geological sample within a core holder, introducing hydrogen at a first preset pressure into a second diffusion chamber via a hydrogen supply mechanism, and introducing nitrogen at a second preset pressure into the first diffusion chamber via a first gas supply mechanism. A detection mechanism monitors the hydrogen concentration in both the first and second diffusion chambers in real time, analyzing and calculating the hydrogen diffusion coefficient and diffusion flux in the geological sample. Furthermore, different geological samples can be used according to experimental needs, eliminating the need for different geological structures. To meet the requirements for hydrogen diffusion testing on different types of geological structures, field tests were conducted to obtain the diffusion coefficient and diffusion flux of hydrogen under different geological samples, gas concentrations, and temperature and pressure conditions. Based on experimental data under the influence of multiple factors, a numerical simulation model of the hydrogen diffusion process was constructed. This allows for a systematic assessment of the leakage risk of hydrogen storage sites under different operating conditions, reducing the cost of simulating hydrogen diffusion characteristics on different types of geological structures, shortening the experimental time required for hydrogen storage site selection, and improving the efficiency of hydrogen storage site selection. This provides reliable experimental data support for the airtightness evaluation of underground hydrogen storage sites and the selection of hydrogen storage sites. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] Figure 1 A schematic diagram of the detection mechanism, core holder, and vacuum pumping mechanism of the hydrogen diffusion experimental apparatus provided in this application;

[0023] Figure 2 A schematic diagram of the hydrogen diffusion experimental apparatus provided in this application;

[0024] Figure 3 for Figure 2 Enlarged view of part A;

[0025] Figure 4 for Figure 2 Enlarged view of part B.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100. Core holder; 110. First diffusion chamber; 120. Sample chamber; 130. Second diffusion chamber;

[0028] 200. Hydrogen supply mechanism; 210. Hydrogen storage unit; 220. Gas transmission unit; 221. Third connecting pipeline; 222. Fourth control valve; 223. Fifth control valve; 224. First high-pressure piston intermediate container; 225. First gas chamber; 226. First piston; 227. Sixth control valve; 228. First gas injection chamber; 229. Seventh control valve;

[0029] 300. First gas supply mechanism; 310. First gas storage unit; 320. First conveying unit; 321. Fourth connecting pipeline; 322. Eighth control valve; 323. Second high-pressure piston intermediate container; 324. Second gas chamber; 325. Second piston; 326. Ninth control valve; 327. Second gas injection chamber; 328. Tenth control valve;

[0030] 400. Testing mechanism; 410. First connecting pipeline; 420. First control valve; 430. Second connecting pipeline; 440. Second control valve; 450. Third control valve; 460. Quadrupole; 470. First capillary sampler; 480. Second capillary sampler; 490. First pressure reducing valve; 491. Second pressure reducing valve; 492. First flow controller; 493. Second flow controller;

[0031] 500. Second gas supply mechanism; 510. Second gas storage unit; 520. Second conveying unit; 521. Sixth connecting pipeline; 522. Thirteenth control valve; 523. Fourteenth control valve; 524. Fourth high-pressure piston intermediate container; 525. Fourth gas chamber; 526. Fourth piston; 527. Fifteenth control valve; 528. Third gas injection chamber; 529. Sixteenth control valve;

[0032] 600. Conveying mechanism; 610. Eleventh control valve; 620. Twelfth control valve; 630. Fifth connecting pipeline; 640. Third high-pressure piston intermediate container; 641. Third air chamber; 642. Third piston;

[0033] 700, Pressure balancing mechanism; 710, Cylinder; 720, Balance piston; 730, Seventh connecting pipe; 740, Seventeenth control valve; 750, Eighth connecting pipe; 760, Eighteenth control valve;

[0034] 800. Voltage stabilizing mechanism; 810. Opening and closing element; 811. First input terminal; 812. Second output terminal; 813. Third output terminal; 814. Fourth output terminal; 815. Fifth output terminal; 820. Constant pressure element;

[0035] 900. Vacuum pumping mechanism; 910. Ninth connecting pipe; 920. Vacuum pump; 930. Pressure simulation mechanism; 931. Tenth connecting pipe; 932. Eleventh connecting pipe; 933. Confining pressure pump.

[0036] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] In related technologies, hydrogen exists in gaseous form at normal temperature and pressure. Due to its low density, flammability, explosiveness, and tendency to diffuse and leak, to achieve safe, efficient, and large-capacity hydrogen storage, it is necessary to select existing geological structures with high safety, low modification costs, and large storage space as hydrogen storage facilities. Existing geological structures include depleted oil and gas reservoirs, salt caverns, deep aquifers, and tight reservoirs. In the traditional process of selecting sites for underground hydrogen storage facilities, it is usually necessary to conduct on-site geological sampling, in-situ testing, on-site gas injection tests, and sealing verification tests for different types of geological structures to obtain and determine the lithological composition, mechanical property parameters, permeability parameters, and caprock sealing performance parameters of different geological structures. Based on the measured parameters of different types of geological structures, corresponding geological models are constructed for numerical simulation calculations. The storage capacity, long-term storage stability, and sealing performance of different geological structures are analyzed and compared to select target geological structures with large storage space, strong sealing, and stable geological conditions, thereby determining the site selection for the hydrogen storage facility.

[0039] However, the selection of hydrogen storage sites requires field tests for different types of geological structures, and geological models need to be constructed and numerical simulations conducted based on the relevant parameters of different geological structures. The field test process is cumbersome, the geological model construction is repetitive, and the data processing volume is large, which reduces the efficiency of hydrogen storage site selection, prolongs the site selection time, and increases the cost of preliminary exploration and simulation analysis.

[0040] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0041] Combination Figure 1 , Figure 2 and Figure 3 This application provides a hydrogen diffusion experimental apparatus, including a core holder 100, a hydrogen supply mechanism 200, a first gas supply mechanism 300, and a detection mechanism 400. The core holder 100 has a first diffusion chamber 110, a sample chamber 120, and a second diffusion chamber 130 inside. The first diffusion chamber 110 and the second diffusion chamber 130 are respectively arranged on opposite sides of the sample chamber 120, and the sample chamber 120 is used to contain geological samples. The hydrogen supply mechanism 200 is connected to the second diffusion chamber 130 and is used to deliver hydrogen to the second diffusion chamber 130 under a first preset pressure. The first gas supply mechanism 300 is connected to the first diffusion chamber 110 and is used to deliver gas to the first diffusion chamber 110 under a second preset pressure. The detection mechanism 400 is connected to both the first diffusion chamber 110 and the second diffusion chamber 130 and is used to detect the gas concentration in the first diffusion chamber 110 and the second diffusion chamber 130.

[0042] In this embodiment, the first gas supply mechanism 300 is used to deliver nitrogen to the first diffusion chamber 110 under a second preset pressure. By delivering nitrogen in the first diffusion chamber 110 and hydrogen in the second diffusion chamber 130, and since nitrogen is an inert protective gas, nitrogen and hydrogen will not react chemically at room temperature and pressure, which reduces interference with hydrogen concentration detection and makes the experimental results more accurate and reliable.

[0043] In other embodiments, the first gas supply mechanism 300 can also be used to deliver methane to the first diffusion chamber 110 under a second preset pressure. By delivering methane in the first diffusion chamber 110 and hydrogen in the second diffusion chamber 130, and since methane and hydrogen do not react chemically at room temperature and pressure, interference with hydrogen concentration detection is reduced, making the experimental results more accurate and reliable.

[0044] By employing the above technical solution, a geological sample is placed inside a core holder 100. Hydrogen gas at a first preset pressure is introduced into the second diffusion chamber 130 via a hydrogen supply mechanism 200, and nitrogen gas at a second preset pressure is introduced into the first diffusion chamber 110 via a first gas supply mechanism 300. This simulates the concentration-driven diffusion process of hydrogen in the geological sample. The hydrogen concentration in the first and second diffusion chambers 110 and 130 is monitored in real time by a detection mechanism 400. The diffusion coefficient and diffusion flux of hydrogen in the geological sample are analyzed and calculated. Furthermore, different geological samples can be used according to experimental needs, eliminating the need for different geological structures. To meet the requirements for hydrogen diffusion testing on different types of geological structures, field tests were conducted to obtain the diffusion coefficient and diffusion flux of hydrogen under different geological samples, gas concentrations, and temperature and pressure conditions. Based on experimental data under the influence of multiple factors, a numerical simulation model of the hydrogen diffusion process was constructed. This allows for a systematic assessment of the leakage risk of hydrogen storage sites under different operating conditions, reducing the cost of simulating hydrogen diffusion characteristics on different types of geological structures, shortening the experimental time required for hydrogen storage site selection, and improving the efficiency of hydrogen storage site selection. This provides reliable experimental data support for the airtightness evaluation of underground hydrogen storage sites and the selection of hydrogen storage sites.

[0045] In this embodiment, the detection mechanism 400 includes a first connecting pipe 410, a first control valve 420, a second connecting pipe 430, a second control valve 440, a third control valve 450, and a quadrupole 460. One end of the first connecting pipe 410 is connected to the first diffusion chamber 110, and the other end of the first connecting pipe 410 is connected to the quadrupole 460. The first control valve 420 and the third control valve 450 are connected to the first connecting pipe 410 and are used to open and close the first connecting pipe 410. One end of the second connecting pipe 430 is connected to the second diffusion chamber 130, and the other end of the second connecting pipe 430 is connected to the first connecting pipe 410. The second control valve 440 is connected to the second connecting pipe 430 and is used to open and close the second connecting pipe 430. The quadrupole 460 is used to detect the concentration of hydrogen in the first diffusion chamber 110 and the second diffusion chamber 130.

[0046] A first capillary sampler 470 is installed on the first connecting pipe 410. The first capillary sampler 470 is used to extract gas in the first diffusion chamber 110. It has a small sampling volume and fast response, which can reduce the impact on the pressure in the first diffusion chamber 110. At the same time, it reduces the situation where a large amount of gas rushes into the quadrupole 460 instantly, reducing the risk of gas overload and other problems in the quadrupole 460, thereby improving the accuracy of the quadrupole 460 in detecting hydrogen concentration.

[0047] A second capillary sampler 480 is installed on the second connecting pipe 430. The second capillary sampler 480 is used to extract gas in the second diffusion chamber 130. It has a small sampling volume and fast response, which can reduce the impact on the pressure in the second diffusion chamber 130. At the same time, it reduces the situation where a large amount of gas rushes into the quadrupole 460 instantly, reducing the risk of gas overload and other problems in the quadrupole 460, thereby improving the accuracy of the quadrupole 460 in detecting hydrogen concentration.

[0048] A first pressure reducing valve 490 is provided on the first connecting pipe 410. The first pressure reducing valve 490 is used to reduce the gas pressure in the first connecting pipe 410 to a low pressure range that the quadrupole 460 can adapt to, so that the gas pressure entering the quadrupole 460 remains stable, reducing the direct impact of high pressure gas on the quadrupole 460, thereby reducing the risk of damage to the quadrupole 460.

[0049] A second pressure reducing valve 491 is provided on the second connecting pipe 430. The second pressure reducing valve 491 is used to reduce the gas pressure in the second connecting pipe 430 to a low pressure range that the quadrupole 460 can adapt to, so that the gas pressure entering the quadrupole 460 remains stable, reducing the direct impact of high pressure gas on the quadrupole 460, thereby reducing the risk of damage to the quadrupole 460.

[0050] A first flow controller 492 is installed on the first connecting pipe 410. By adjusting the opening of the first flow controller 492, the flow rate of the gas in the first connecting pipe 410 is controlled, so that the gas flow rate entering the quadrupole 460 remains constant, making the hydrogen concentration signal more stable during the detection process of the quadrupole 460, thereby improving the accuracy of the quadrupole 460 in detecting hydrogen concentration.

[0051] A second flow controller 493 is installed on the second connecting pipe 430. By adjusting the opening of the second flow controller 493, the flow rate of the gas in the second connecting pipe 430 is controlled, so that the gas flow rate entering the quadrupole 460 remains constant, making the hydrogen concentration signal more stable during the detection process of the quadrupole 460, thereby improving the accuracy of the quadrupole 460 in detecting hydrogen concentration.

[0052] In this embodiment, hydrogen is supplied to the second diffusion chamber 130 via the hydrogen supply mechanism 200, and nitrogen is supplied to the first diffusion chamber 110 via the first gas supply mechanism 300. When the initial hydrogen concentration in the second diffusion chamber 130 is detected, the second control valve 440 and the third control valve 450 are opened, and the first control valve 420 is closed. Gas is extracted from the second diffusion chamber 130 via the second capillary sampler 480. The extracted gas is then transported to the quadrupole 460 via the second connecting pipe 430. Simultaneously, the gas enters the quadrupole 460 at a fixed pressure and flow rate via the second pressure reducing valve 491 and the second flow controller 493. The quadrupole 460 detects and records the initial hydrogen concentration in the second diffusion chamber 130. When the initial hydrogen concentration in the first diffusion chamber 110 is detected, the second control valve 440 is closed, and the first control valve 420 and the third control valve 450 are opened. The first capillary sampler 470 extracts gas from the first diffusion chamber 110. The extracted gas is delivered to the quadrupole 460 through the first connecting pipe 410. Simultaneously, the gas enters the quadrupole 460 at the same pressure and flow rate through the first pressure reducing valve 490 and the first flow controller 492. The quadrupole 460 detects and records the initial hydrogen concentration in the second diffusion chamber 130, and closes the first control valve 420 and the third control valve 450. Driven by the hydrogen concentration in the second diffusion chamber 130, hydrogen diffuses from the second diffusion chamber 130 through the geological sample to the first diffusion chamber 110. After a certain period of time, the above steps are repeated, and the hydrogen concentration in the first diffusion chamber 110 and the second diffusion chamber 130 is detected and recorded multiple times to determine the hydrogen concentration in the first diffusion chamber 110 and the second diffusion chamber 130, thereby improving the accuracy and reliability of the diffusion coefficient and diffusion flux calculation.

[0053] The hydrogen supply mechanism 200 includes a hydrogen storage component 210 and a gas delivery component 220. The gas delivery component 220 is connected between the hydrogen storage component 210 and the second diffusion chamber 130. The hydrogen storage component 210 is used to store hydrogen gas, and the gas delivery component 220 is used to deliver the hydrogen gas stored in the hydrogen storage component 210 to the second diffusion chamber 130 under a first preset pressure.

[0054] In this embodiment, the hydrogen storage component 210 includes a hydrogen storage tank for storing hydrogen gas. The gas delivery component 220 includes a third connecting pipe 221, a fourth control valve 222, a fifth control valve 223, and a first high-pressure piston intermediate container 224. One end of the third connecting pipe 221 is connected to the output end of the hydrogen storage tank, and the other end of the third connecting pipe 221 is connected to the second diffusion chamber 130. The fourth control valve 222 and the fifth control valve 223 are both disposed on the third connecting pipe 221. The fourth control valve 222 is used to open and close the third connecting pipe. The third connecting pipe 221 is used to supply or stop supplying hydrogen to the second diffusion chamber 130. The fifth control valve 223 is used to open or close the third connecting pipe 221 to supply or stop supplying hydrogen to the first high-pressure piston intermediate container 224. The first high-pressure piston intermediate container 224 is disposed on the third connecting pipe 221. The first high-pressure piston intermediate container 224 includes a first gas chamber 225 and a first piston 226. The first piston 226 is slidably disposed in the first gas chamber 225. The first gas chamber 225 is connected to the third connecting pipe 221.

[0055] The third connecting pipe 221 is equipped with a sixth control valve 227, a first gas injection chamber 228, and a seventh control valve 229. The sixth control valve 227 and the seventh control valve 229 are located on both sides of the first gas injection chamber 228, respectively. The sixth control valve 227 and the seventh control valve 229 are used to open and close the third connecting pipe 221. When the sixth control valve 227 is opened and the seventh control valve 229 is closed, hydrogen can enter the first gas injection chamber 228 along the third connecting pipe 221. The hydrogen pressure in the first gas injection chamber 228 is stabilized, providing a stable and uniform gas intake environment for the diffusion test of hydrogen in geological samples.

[0056] In this embodiment, when the hydrogen supply mechanism 200 supplies hydrogen to the second diffusion chamber 130, the sixth control valve 227 is opened, the seventh control valve 229 and the fourth control valve 222 are closed, and the third connecting pipe 221 supplies hydrogen to the first injection chamber 228. After a certain period of time, the hydrogen pressure in the first injection chamber 228 stabilizes, the seventh control valve 229 and the fifth control valve 223 are opened, and the first piston 226 is driven to move backward. The hydrogen in the first injection chamber 228 is drawn into the first gas chamber 225 through the third connecting pipe 221. The seventh control valve 229 is closed, the fourth control valve 222 is opened, and the first piston 226 is driven to move forward. The third connecting pipe 221 supplies hydrogen from the first gas chamber 225 to the second diffusion chamber 130.

[0057] By adopting the aforementioned technical solution, the third connecting pipe 221, multiple control valves, the first high-pressure piston intermediate container 224, and the first gas injection chamber 228 work together to control the opening and closing of the corresponding valves according to a preset timing sequence. This sequentially achieves the stabilization of hydrogen gas pressure in the first gas injection chamber 228, the temporary storage and pressure regulation in the first high-pressure piston intermediate container 224, and the delivery of hydrogen gas that has reached the first preset pressure and is uniformly stable into the second diffusion chamber 130. This provides continuous and stable gas intake conditions for hydrogen diffusion testing of geological samples, ensuring that the experimental process is stable and controllable and the experimental data is accurate and reliable.

[0058] The first gas supply mechanism 300 includes a first gas storage component 310 and a first conveying component 320. The first conveying component 320 is connected between the first gas storage component 310 and the first diffusion chamber 110. The first gas storage component 310 is used to store gas, and the first conveying component 320 is used to convey the gas stored in the first gas storage component 310 to the first diffusion chamber 110 under a second preset pressure.

[0059] In this embodiment, the first preset pressure and the second preset pressure are equal, so that the nitrogen in the first diffusion chamber 110 and the hydrogen in the second diffusion chamber 130 will not pass through the geological sample due to the pressure difference, thereby improving the accuracy and reliability of the experimental detection results.

[0060] In this embodiment, the first gas storage component 310 includes a nitrogen storage tank for storing nitrogen gas. The first conveying component 320 includes a fourth connecting pipe 321, an eighth control valve 322, and a second high-pressure piston intermediate container 323. One end of the fourth connecting pipe 321 is connected to the output end of the nitrogen storage tank, and the other end of the fourth connecting pipe 321 is connected to the first diffusion chamber 110. The eighth control valve 322 is used to open and close the fourth connecting pipe 321. The second high-pressure piston intermediate container 323 is disposed on the fourth connecting pipe 321. The second high-pressure piston intermediate container 323 includes a second gas chamber 324 and a second piston 325. The second piston 325 is slidably disposed in the second gas chamber 324, and the second gas chamber 324 is connected to the fourth connecting pipe 321.

[0061] The fourth connecting pipe 321 is equipped with a ninth control valve 326, a second gas injection chamber 327, and a tenth control valve 328. The ninth control valve 326 and the tenth control valve 328 are located on both sides of the second gas injection chamber 327, respectively. The ninth control valve 326 and the tenth control valve 328 are used to open and close the fourth connecting pipe 321. When the ninth control valve 326 is opened and the tenth control valve 328 is closed, nitrogen can enter the second gas injection chamber 327 along the fourth connecting pipe 321. The nitrogen in the second gas injection chamber 327 is stable, providing a stable and uniform gas intake environment for nitrogen delivery and experimental testing.

[0062] In this embodiment, when the first gas supply mechanism 300 supplies nitrogen to the first diffusion chamber 110, the ninth control valve 326 is opened, the tenth control valve 328 and the eighth control valve 322 are closed, and the fourth connecting pipe 321 supplies nitrogen to the second injection chamber 327. After a certain period of time, the nitrogen pressure in the second injection chamber 327 stabilizes, the tenth control valve 328 is opened, and the second piston 325 is driven to move backward. The nitrogen in the second injection chamber 327 is drawn into the second gas chamber 324 through the fourth connecting pipe 321. The tenth control valve 328 is closed, the eighth control valve 322 is opened, and the second piston 325 is driven to move forward. The fourth connecting pipe 321 supplies nitrogen from the second gas chamber 324 to the first diffusion chamber 110.

[0063] Through the above technical solution, the fourth connecting pipe 321, multiple control valves, the second high-pressure piston intermediate container 323 and the second gas injection chamber 327 work together to control the opening and closing of the corresponding valves according to the preset timing sequence. This achieves the stabilization of nitrogen gas pressure in the second gas injection chamber 327, the temporary storage and pressure regulation in the second high-pressure piston intermediate container 323, and the delivery of nitrogen gas that has reached the second preset pressure and is uniformly stable into the first diffusion chamber 110. This maintains the internal pressure stability of the first diffusion chamber 110, reduces the disturbance of pressure fluctuations to the hydrogen diffusion process, and ensures that the experimental process is stable and controllable and the experimental data is accurate and reliable.

[0064] The hydrogen diffusion experimental apparatus also includes a second gas supply mechanism 500 and a conveying mechanism 600. The second gas supply mechanism 500 is connected to the conveying mechanism 600, and the conveying mechanism 600 is connected to the second diffusion chamber 130. The second gas supply mechanism 500 is used to deliver gas to the conveying mechanism 600 under a third preset pressure. The hydrogen supply mechanism 200 is used to deliver hydrogen to the conveying mechanism 600 or the second diffusion chamber 130 under a first preset pressure. The conveying mechanism 600 is used to mix the gas from the second gas supply mechanism 500 and the hydrogen from the hydrogen supply mechanism 200 and deliver them to the second diffusion chamber 130.

[0065] In this embodiment, the second gas supply mechanism 500 is used to deliver methane to the delivery mechanism 600 under a third preset pressure. By delivering methane in the delivery mechanism 600, the concentration of hydrogen is adjusted. At room temperature and pressure, methane and hydrogen do not react chemically, which reduces interference with the detection of hydrogen concentration and makes the experimental results more accurate and reliable.

[0066] In other embodiments, the second gas supply mechanism 500 can also be used to deliver nitrogen to the delivery mechanism 600 under a third preset pressure. By delivering nitrogen in the delivery mechanism 600, the concentration of hydrogen can be adjusted. Nitrogen is an inert protective gas, and nitrogen and hydrogen will not react chemically at room temperature and pressure, which reduces interference with the detection of hydrogen concentration and makes the experimental results more accurate and reliable.

[0067] In this embodiment, the first preset pressure and the third preset pressure are equal, so that the hydrogen supplied by the hydrogen supply mechanism 200 and the methane supplied by the second gas supply mechanism 500 are kept at the same pressure. This allows them to be stably combined within the conveying mechanism 600, reducing the possibility of gas backflow and uneven flow rate, and improving the stability of the hydrogen diffusion experiment and the accuracy of the experimental results.

[0068] In this embodiment, the conveying mechanism 600 includes an eleventh control valve 610, a twelfth control valve 620, a fifth connecting pipe 630, and a third high-pressure piston intermediate container 640. One end of the fifth connecting pipe 630 is connected to the third high-pressure piston intermediate container 640, and the other end of the fifth connecting pipe 630 is connected to the second diffusion chamber 130. The eleventh control valve 610 and the twelfth control valve 620 are both disposed on the fifth connecting pipe 630 and are used to open and close the fifth connecting pipe 630. The third high-pressure piston intermediate container 640 includes a third air chamber 641 and a third piston 642. The third piston 642 is slidably disposed in the third air chamber 641, and the third air chamber 641 is connected to the fifth connecting pipe 630.

[0069] In this embodiment, when the hydrogen supply mechanism 200 supplies hydrogen to the third gas chamber 641, the sixth control valve 227 is opened, and the seventh control valve 229 and the fourth control valve 222 are closed. The third connecting pipe 221 supplies hydrogen to the first injection chamber 228. After a certain period of time, the hydrogen pressure in the first injection chamber 228 stabilizes. The seventh control valve 229 and the fifth control valve 223 are then opened, driving the first piston 226 to move backward. The hydrogen in the first injection chamber 228 is drawn into the first gas chamber 225 through the third connecting pipe 221. The seventh control valve 229 and the eleventh control valve 222 are then closed. 0. Open the fourth control valve 222 and the twelfth control valve 620, drive the first piston 226 to move forward, drive the third piston 642 to move backward, and the third connecting pipe 221 delivers hydrogen from the first gas chamber 225 to the third gas chamber 641. After mixing with the methane delivered to the third gas chamber 641 at the same time through the second gas supply mechanism 500, open the eleventh control valve 610, close the fourth control valve 222, and drive the third piston 642 to move forward, so that the methane and hydrogen in the third gas chamber 641 are mixed and delivered to the second diffusion chamber 130 through the fifth connecting pipe 630.

[0070] By adopting the above technical solution, the methane from the second gas supply mechanism 500 and the hydrogen from the hydrogen supply mechanism 200 are mixed in the third high-pressure piston intermediate container 640 through the fifth connecting pipe 630, the eleventh control valve 610, the twelfth control valve 620, and the third high-pressure piston intermediate container 640 to obtain mixed gases with different hydrogen concentrations. The mixture is then stably delivered to the second diffusion chamber 130 under a third preset pressure. The mixing, pressure stabilization, and delivery processes are carried out in an orderly manner through the timing control of the control valves, providing uniform composition and stable pressure intake conditions for diffusion experiments at different hydrogen concentrations, ensuring accurate and reliable experimental testing.

[0071] The second gas supply mechanism 500 includes a second gas storage component 510 and a second conveying component 520. The second conveying component 520 is connected between the second gas storage component 510 and the conveying mechanism 600. The second gas storage component 510 is used to store gas, and the second conveying component 520 is used to convey the gas stored in the second gas storage component 510 to the conveying mechanism 600 under a third preset pressure.

[0072] In this embodiment, the second gas storage component 510 includes a methane tank for storing methane. The second conveying component 520 includes a sixth connecting pipe 521, a thirteenth control valve 522, a fourteenth control valve 523, and a fourth high-pressure piston intermediate container 524. One end of the sixth connecting pipe 521 is connected to the output end of the methane tank, and the other end of the sixth connecting pipe 521 is connected to the conveying mechanism 600. The thirteenth control valve 522 and the fourteenth control valve 523 are both disposed on the sixth connecting pipe 521. The thirteenth control valve 522 is used to open and close the fourth high-pressure piston intermediate container 524. A sixth connecting pipe 521 is used to supply or stop supplying methane to the conveying mechanism 600. A fourteenth control valve 523 is used to open or close the sixth connecting pipe 521 to supply or stop supplying nitrogen to the fourth high-pressure piston intermediate container 524. The fourth high-pressure piston intermediate container 524 is disposed on the sixth connecting pipe 521. The fourth high-pressure piston intermediate container 524 includes a fourth gas chamber 525 and a fourth piston 526. The fourth piston 526 is slidably disposed in the fourth gas chamber 525. The fourth gas chamber 525 is connected to the sixth connecting pipe 521.

[0073] The sixth connecting pipe 521 is equipped with a fifteenth control valve 527, a third gas injection chamber 528, and a sixteenth control valve 529. The fifteenth control valve 527 and the sixteenth control valve 529 are located on both sides of the third gas injection chamber 528, respectively. The fifteenth control valve 527 and the sixteenth control valve 529 are used to open and close the sixth connecting pipe 521. When the fifteenth control valve 527 is opened and the sixteenth control valve 529 is closed, methane can enter the third gas injection chamber 528 along the sixth connecting pipe 521. The methane pressure in the third gas injection chamber 528 is stabilized, providing a stable and uniform gas intake environment for methane delivery and experimental testing.

[0074] In this embodiment, when the hydrogen supply mechanism 200 supplies hydrogen to the third gas chamber 641, the sixth control valve 227 is opened, and the seventh control valve 229 and the fourth control valve 222 are closed. The third connecting pipe 221 supplies hydrogen to the first injection chamber 228. After a certain period of time, the hydrogen pressure in the first injection chamber 228 stabilizes. The seventh control valve 229 and the fifth control valve 223 are then opened, driving the first piston 226 to move backward. The hydrogen in the first injection chamber 228 then flows through the third connecting pipe 221. Hydrogen gas is drawn into the first gas chamber 225. The seventh control valve 229 and the eleventh control valve 610 are closed, while the fourth control valve 222 and the twelfth control valve 620 are opened. This drives the first piston 226 forward and simultaneously drives the third piston 642 backward. Hydrogen gas in the first gas chamber 225 is then drawn into the third gas chamber 641 via the third connecting pipe 221. When the second gas supply mechanism 500 supplies methane to the third gas chamber 641, the fifteenth control valve 527 is opened and the sixteenth control valve 528 is closed. Control valves 529 and 13, and the sixth connecting pipe 521 deliver methane to the third injection chamber 528. After a certain period of time, the methane pressure in the third injection chamber 528 stabilizes. Control valves 529 and 14, and 16, and control valves 523 are opened, driving the fourth piston 526 to move backward. The methane in the third injection chamber 528 is then drawn into the fourth gas chamber 525 via the sixth connecting pipe 521. Control valves 529 and 11, and control valves 510 are closed. Control valves 522 and 14, and control valves 525 are opened. The twelfth control valve 620 drives the fourth piston 526 to move forward and simultaneously drives the third piston 642 to move backward. Methane in the fourth gas chamber 525 is drawn into the third gas chamber 641 through the sixth connecting pipe 521. Then, the thirteenth control valve 522 and the fourth control valve 222 are closed, and the eleventh control valve 610 is opened, driving the third piston 642 to move forward. This allows the methane and hydrogen in the third gas chamber 641 to be mixed and then transported to the second diffusion chamber 130 through the fifth connecting pipe 630.

[0075] By adopting the above technical solution, the sixth connecting pipe 521, multiple control valves, the fourth high-pressure piston intermediate container 524, and the third gas injection chamber 528 cooperate with each other to control the opening and closing of each valve according to a preset time sequence. This sequentially achieves the stabilization of methane pressure in the third gas injection chamber 528, the temporary storage and pressure regulation in the fourth high-pressure piston intermediate container 524, and finally delivers methane with a stable and uniform pressure at the third preset pressure to the conveying mechanism 600. This provides precise pressure, stable flow, and uniform gas distribution for the subsequent preparation and diffusion experiments of hydrogen and methane mixtures, ensuring that the experimental process is stable and controllable and the test data is accurate and reliable.

[0076] The hydrogen diffusion experimental apparatus also includes a pressure balancing mechanism 700, which is connected between the first diffusion chamber 110 and the second diffusion chamber 130. The pressure balancing mechanism 700 is used to adjust the pressure of the first diffusion chamber 110 and the second diffusion chamber 130 to be equal.

[0077] By adopting the above technical solution, by connecting the pressure balancing mechanism 700 between the first diffusion chamber 110 and the second diffusion chamber 130, the pressure of the first diffusion chamber 110 and the second diffusion chamber 130 can be adjusted to be equal in real time, eliminating the pressure difference between the first diffusion chamber 110 and the second diffusion chamber 130, ensuring that hydrogen diffuses only under the drive of the concentration gradient, and improving the accuracy and reliability of the experiment.

[0078] The pressure balancing mechanism 700 includes a cylinder 710 and a balancing piston 720. One end of the cylinder 710 is connected to the first diffusion chamber 110, and the other end of the cylinder 710 is connected to the second diffusion chamber 130. The balancing piston 720 is slidably connected inside the cylinder 710.

[0079] In this embodiment, when the air pressure in the first diffusion chamber 110 is less than the air pressure in the second diffusion chamber 130, the balance piston 720 slides inside the cylinder 710 toward the side where the first diffusion chamber 110 is located; when the air pressure in the first diffusion chamber 110 is equal to the air pressure in the second diffusion chamber 130, the balance piston 720 remains stationary or remains stationary; when the air pressure in the first diffusion chamber 110 is greater than the air pressure in the second diffusion chamber 130, the balance piston 720 slides inside the cylinder 710 toward the side where the second diffusion chamber 130 is located.

[0080] By adopting the above technical solution, and by sliding the balance piston 720 inside the cylinder 710, the pressure between the first diffusion chamber 110 and the second diffusion chamber 130 can be balanced by the sliding of the balance piston 720. This reduces the interference of the pressure difference between the first diffusion chamber 110 and the second diffusion chamber 130 on the hydrogen diffusion behavior, allowing hydrogen to diffuse only under the action of the concentration gradient. This improves the stability and repeatability of the experimental test, makes the experimental results closer to the hydrogen diffusion law under real geological conditions, and improves the experimental accuracy and data reliability.

[0081] In this embodiment, the pressure balancing mechanism 700 is provided with a seventh connecting pipe 730, a seventeenth control valve 740, an eighth connecting pipe 750, and an eighteenth control valve 760. One end of the cylinder 710 is connected to one end of the seventh connecting pipe 730, and the other end of the cylinder 710 is connected to one end of the eighth connecting pipe 750. The seventeenth control valve 740 is provided on the seventh connecting pipe 730 and is used to open and close the seventh connecting pipe 730. The eighteenth control valve 760 is provided on the eighth connecting pipe 750 and is used to open and close the eighth connecting pipe 750. The seventh connecting pipe 730 and the eighth connecting pipe 750 are used for venting to discharge impurity gas and residual gas.

[0082] The hydrogen diffusion experimental apparatus also includes a pressure stabilizing mechanism 800, which is connected to the hydrogen supply mechanism 200, the first gas supply mechanism 300, and the second gas supply mechanism 500. The pressure stabilizing mechanism 800 is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism 200, the first gas supply mechanism 300, and the second gas supply mechanism 500, so that the hydrogen pressure inside the hydrogen supply mechanism 200 is a first preset pressure, the gas pressure inside the first gas supply mechanism 300 is a second preset pressure, and the gas pressure inside the second gas supply mechanism 500 is a third preset pressure.

[0083] In this embodiment, the pressure stabilizing mechanism 800 is connected to the hydrogen supply mechanism 200, the first gas supply mechanism 300, the second gas supply mechanism 500, and the conveying mechanism 600. The pressure stabilizing mechanism 800 is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism 200, the first gas supply mechanism 300, the second gas supply mechanism 500, and the conveying mechanism 600, so that the hydrogen pressure in the hydrogen supply mechanism 200 is a first preset pressure, the gas pressure in the first gas supply mechanism 300 is a second preset pressure, the gas pressure in the second gas supply mechanism 500 is a third preset pressure, and the gas pressure in the conveying mechanism 600 is a fourth preset pressure.

[0084] By adopting the above technical solution, the hydrogen pressure in the hydrogen supply mechanism 200 is maintained at the first preset pressure by the pressure stabilizing mechanism 800, the gas pressure in the first gas supply mechanism 300 is maintained at the second preset pressure, the gas pressure in the second gas supply mechanism 500 is maintained at the third preset pressure, and the gas pressure in the conveying mechanism 600 is maintained at the fourth preset pressure. This reduces the impact of pressure fluctuations on gas conveying, the mixing ratio of hydrogen and methane, and the hydrogen diffusion behavior, thereby stabilizing experimental parameters and making the process controllable, and improving the accuracy and reliability of experimental data.

[0085] like Figure 4As shown, the pressure stabilizing mechanism 800 includes an opening / closing element 810 and a constant pressure element 820. The opening / closing element 810 is connected to the hydrogen supply mechanism 200, the first gas supply mechanism 300, and the second gas supply mechanism 500. The constant pressure element 820 is connected to the opening / closing element 810. The opening / closing element 810 is used to connect at least one of the hydrogen supply mechanism 200, the first gas supply mechanism 300, and the second gas supply mechanism 500 with the constant pressure element 820. The constant pressure element 820 is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism 200, the first gas supply mechanism 300, and the second gas supply mechanism 500 through the opening / closing element 810.

[0086] In this embodiment, the constant pressure component 820 is a constant speed and constant pressure pump, and the opening and closing component 810 has a first input terminal 811, a second output terminal 812, a third output terminal 813, a fourth output terminal 814, and a fifth output terminal 815. The first input terminal 811 is connected to the constant speed and constant pressure pump, the second output terminal 812 is connected to the fourth air chamber 525, the third output terminal 813 is connected to the first air chamber 225, the fourth output terminal 814 is connected to the third air chamber 641, and the fifth output terminal 815 is connected to the second air chamber 324.

[0087] In this embodiment, when hydrogen from the hydrogen supply mechanism 200 is directly supplied to the second diffusion chamber 130, nitrogen from the first gas supply mechanism 300 is simultaneously directly supplied to the first diffusion chamber 110. The first input terminal 811, the third output terminal 813, and the fifth output terminal 815 are opened, while the second output terminal 812 and the fourth output terminal 814 are closed, to maintain the first preset pressure of the hydrogen supply mechanism 200 equal to the second preset pressure of the first gas supply mechanism 300. When hydrogen from the hydrogen supply mechanism 200 and methane from the second gas supply mechanism 500 are mixed in the conveying mechanism 600 and then supplied to the second diffusion chamber 130, before the hydrogen from the hydrogen supply mechanism 200 and the methane from the second gas supply mechanism 500 are mixed, the first input terminal 811, the third output terminal 813, and the fifth output terminal 815 are opened, while the second output terminal 812 and the fourth output terminal 814 are closed, to maintain the first preset pressure of the hydrogen supply mechanism 200 equal to the second preset pressure of the first gas supply mechanism 300. The first input terminal 811, the second output terminal 812, and the third output terminal 813 are connected, while the fourth output terminal 814 and the fifth output terminal 815 are closed, to maintain the first preset pressure of the hydrogen supply mechanism 200 equal to the third preset pressure of the second gas supply mechanism 500. After the hydrogen from the hydrogen supply mechanism 200 is mixed with the methane from the second gas supply mechanism 500, and at the same time the nitrogen from the first gas supply mechanism 300 is directly delivered to the first diffusion chamber 110, the first input terminal 811, the fourth output terminal 814, and the fifth output terminal 815 are opened, while the second output terminal 812 and the third output terminal 813 are closed, to maintain the second preset pressure of the first gas supply mechanism 300 equal to the fourth preset pressure of the delivery mechanism 600.

[0088] By adopting the above technical solution, the pressure stabilizing mechanism 800, through the cooperation of the opening and closing component 810 and the constant pressure component 820, can selectively connect the hydrogen supply mechanism 200, the first gas supply mechanism 300, the second gas supply mechanism 500, the conveying mechanism 600 and the constant pressure component 820, thereby achieving stable maintenance of the internal gas pressure of the hydrogen supply mechanism 200, the first gas supply mechanism 300, the second gas supply mechanism 500 and the conveying mechanism 600, reducing the impact of pressure fluctuations on gas conveying, the mixing ratio of hydrogen and methane and hydrogen diffusion experiments, and improving the stability of experimental parameters and the reliability of data.

[0089] The hydrogen diffusion experimental apparatus also includes a vacuum pumping mechanism 900 and a pressure simulation mechanism 930. The vacuum pumping mechanism 900 is connected to the core holder 100 and is used to evacuate the core holder 100 to put it in a vacuum state. The pressure simulation mechanism 930 is connected to the core holder 100 and is used to apply pressure to the geological sample inside the core holder 100.

[0090] In this embodiment, the vacuum pumping mechanism 900 includes a ninth connecting pipe 910 and a vacuum pump 920. One end of the ninth connecting pipe 910 is connected to the vacuum pump 920, and the other end of the ninth connecting pipe 910 is connected to the first connecting pipe 410.

[0091] In this embodiment, the pressure simulation mechanism 930 includes a tenth connecting pipe 931, an eleventh connecting pipe 932, and a confining pressure pump 933. One end of the tenth connecting pipe 931 is connected to the confining pressure pump 933, and the other end of the tenth connecting pipe 931 is connected to one end of the core holder 100. One end of the eleventh connecting pipe 932 is connected to the confining pressure pump 933, and the other end of the eleventh connecting pipe 932 is connected to the other end of the core holder 100. The tenth connecting pipe 931 and the eleventh connecting pipe 932 are used to transport the pressure transmitting medium to the confining pressure cavity between the inner wall of the core holder 100 and the outer walls of the sample chamber 120, the first diffusion chamber 110, and the second diffusion chamber 130. The confining pressure pump 933 is used to provide pressure to the pressure transmitting medium, so that the pressure transmitting medium squeezes the sample chamber 120, and the sample chamber 120 transmits the pressure to the geological sample, so that the geological sample is in a uniformly compressed state to simulate the real stress environment of the geological structure.

[0092] In this embodiment, the pressure transmission medium can be hydraulic oil, water, silicone oil, or inert gas. Hydraulic oil, water, silicone oil, or inert gas and other pressure transmission media have stable pressure transmission and chemical properties, and can apply uniform and controllable pressure to geological samples to simulate the real stress environment of geological structures.

[0093] By adopting the above technical solution, the core holder 100 is evacuated by the vacuuming mechanism 900, which can remove impurities and residual gases from the core holder 100, hydrogen supply mechanism 200, first gas supply mechanism 300, second gas supply mechanism 500, conveying mechanism 600 and pressure balancing mechanism 700, reducing the interference of residual gases on the hydrogen diffusion process and providing a pure experimental environment for the diffusion experiment. At the same time, the pressure simulation mechanism 930 applies uniform and stable pressure to the geological sample, making the geological sample fit tightly against the inner wall of the sample chamber 120, thereby reducing the flow gap between the sample chamber 120 and the geological sample, reducing the possibility of hydrogen bypassing along the outer surface of the geological sample, and making the experimental conditions more consistent with the real conditions of the geological structure, thus improving the accuracy and reliability of the hydrogen diffusion test results.

[0094] The hydrogen diffusion experimental apparatus provided in this application involves placing a solid stainless steel cylinder with a diameter equal to the inner diameter of the core holder 100 inside the core holder 100. The confining pressure pump 933 is turned on, and a pressure-transmitting medium is supplied through the tenth connecting pipe 931 and the eleventh connecting pipe 932 into the confining pressure cavity between the inner wall of the core holder 100 and the outer walls of the sample chamber 120, the first diffusion chamber 110, and the second diffusion chamber 130. This ensures the geological sample is under uniform pressure, simulating the real stress environment of the geological structure. Then, the eighth control valve 322, the ninth control valve 326, and the tenth control valve 328 are opened, and nitrogen gas is introduced into the first diffusion chamber 110 through the fourth connecting pipe 321. Simultaneously, the fifteenth control valve 527, the sixteenth control valve 529, the thirteenth control valve 522, and the eleventh control valve 610 are opened, while the twelfth control valve 620 and the fourth control valve 222 are closed. Methane is introduced into the second diffusion chamber 130 through the sixth connecting pipe 521. The first control valve 420, the second control valve 440, the eighth control valve 322, the eleventh control valve 610, the seventeenth control valve 740, and the eighteenth control valve 760 are closed. After standing for two hours, the gas pressure changes in the first diffusion chamber 110 and the second diffusion chamber 130 are observed. There are no significant changes. The seventeenth control valve 740 and the eighteenth control valve 760 are opened. Nitrogen and methane are discharged through the seventh connecting pipe 730 and the eighth connecting pipe 750. The solid stainless steel cylinder in the core holder 100 is replaced with a geological sample. The sixth control valve 227, the ninth control valve 326, the fifteenth control valve 527, the seventeenth control valve 740, and the eighteenth control valve 760 are closed. The other control valves are opened. The vacuum pump 920 is turned on to extract the impurity gas in the core holder 100.

[0095] When the hydrogen supply mechanism 200 supplies hydrogen to the second diffusion chamber 130, the sixth control valve 227 is opened, and the seventh control valve 229 and the fourth control valve 222 are closed. The third connecting pipe 221 supplies hydrogen to the first injection chamber 228. After a certain period of time, the hydrogen pressure in the first injection chamber 228 stabilizes. The seventh control valve 229 and the fifth control valve 223 are then opened, driving the first piston 226 to move backward. The hydrogen in the first injection chamber 228 is drawn into the first gas chamber 225 through the third connecting pipe 221. The fourth control valve 222, the first input terminal 811, and the third output terminal 813 are then opened, and the seventh control valve 229, the second output terminal 812, and the fourth output terminal 814 are closed. The constant speed and constant pressure pump drives the first piston 226 to move forward. Under the first preset pressure, the third connecting pipe 221 supplies hydrogen from the first gas chamber 225 to the second diffusion chamber. Chamber 130; simultaneously, the first gas supply mechanism 300 supplies nitrogen to the first diffusion chamber 110, opens the ninth control valve 326, closes the tenth control valve 328 and the eighth control valve 322, and the fourth connecting pipe 321 delivers nitrogen to the second injection chamber 327. After a certain period of time, the nitrogen pressure in the second injection chamber 327 stabilizes, the tenth control valve 328 is opened, and the constant speed and constant pressure pump drives the second piston 325 to move backward. The nitrogen in the second injection chamber 327 is drawn into the second gas chamber 324 through the fourth connecting pipe 321. The tenth control valve 328, the second output end 812 and the fourth output end 814 are closed, the eighth control valve 322 is opened, the first input end 811 and the fifth output end 815 are opened, and the constant speed and constant pressure pump drives the second piston 325 to move forward. The fourth connecting pipe 321 delivers nitrogen from the second gas chamber 324 to the first diffusion chamber 110.

[0096] When detecting hydrogen concentration, the eleventh control valve 610, the eighth control valve 322, and the second control valve 440 are closed, while the first control valve 420 and the third control valve 450 are opened. Gas is extracted from the first diffusion chamber 110 through the first capillary sampler 470. The extracted gas is then transported to the quadrupole 460 through the first connecting pipe 410 to detect the initial hydrogen concentration in the first diffusion chamber 110. Then, the first control valve 420 is closed, the vacuum pump 920 is turned on, and the first connecting pipe 410 and the second control valve 450 are extracted. After the gas remaining in the pipeline 430 is removed, the second control valve 440 is opened, and the gas in the second diffusion chamber 130 is extracted through the second capillary sampler 480. The extracted gas is delivered to the quadrupole 460 through the second connecting pipeline 430 to detect the initial concentration of hydrogen in the second diffusion chamber 130. After a certain period of time, the above steps are repeated to detect and record the hydrogen concentration in the first diffusion chamber 110 and the second diffusion chamber 130 multiple times to determine the hydrogen concentration in the first diffusion chamber 110 and the second diffusion chamber 130.

[0097] When the hydrogen supply mechanism 200 supplies hydrogen to the third gas chamber 641, the sixth control valve 227 is opened, and the seventh control valve 229 and the fourth control valve 222 are closed. The third connecting pipe 221 delivers hydrogen to the first injection chamber 228. After a certain period of time, the hydrogen pressure in the first injection chamber 228 stabilizes. The seventh control valve 229 and the fifth control valve 223 are then opened, driving the first piston 226 to move backward. The hydrogen in the first injection chamber 228 is then drawn into the first injection chamber 228 via the third connecting pipe 221. Inside gas chamber 225, the seventh control valve 229, the eleventh control valve 610, the fourth output terminal 814, and the fifth output terminal 815 are closed, while the fourth control valve 222, the twelfth control valve 620, the first input terminal 811, and the third output terminal 813 are opened. A constant-speed, constant-pressure pump drives the first piston 226 forward and simultaneously drives the third piston 642 backward. Under a first preset pressure, hydrogen gas in the first gas chamber 225 is drawn into the third gas chamber 641 via the third connecting pipe 221. Simultaneously... The second gas supply mechanism 500 supplies methane to the third gas chamber 641, opens the fifteenth control valve 527, and closes the sixteenth control valve 529 and the thirteenth control valve 522. The sixth connecting pipe 521 delivers methane to the third injection chamber 528. After a certain period of time, the methane pressure in the third injection chamber 528 stabilizes. The sixteenth control valve 529 and the fourteenth control valve 523 are then opened. The constant speed and constant pressure pump drives the fourth piston 526 to move backward, and the methane in the third injection chamber 528 flows through the sixth connecting pipe... The methane in the fourth gas chamber 521 is drawn into the fourth gas chamber 525. The sixteenth control valve 529, the eleventh control valve 610, the fourth output terminal 814 and the fifth output terminal 815 are closed. The thirteenth control valve 522, the twelfth control valve 620 and the second output terminal 812 are opened. The constant speed and constant pressure pump drives the fourth piston 526 to move forward and simultaneously drives the third piston 642 to move backward. Under the third preset pressure, the methane in the fourth gas chamber 525 is drawn into the third gas chamber 641 through the sixth connecting pipe 521.

[0098] Close the thirteenth control valve 522, the fourth control valve 222, the second output terminal 812, and the third output terminal 813. Open the eleventh control valve 610, the first input terminal 811, and the fourth output terminal 814. The constant speed and constant pressure pump drives the third piston 642 to move forward, so that the methane and hydrogen in the third gas chamber 641 are mixed under the fourth preset pressure and then transported to the second diffusion chamber 130 through the fifth connecting pipe 630. At the same time, the first gas supply mechanism 300 supplies nitrogen to the first diffusion chamber 110. Open the ninth control valve 326 and close the tenth control valve 314. Nitrogen gas is delivered to the second injection chamber 327 via the eighth control valve 322 and the fourth connecting pipe 321. After a certain period of time, the nitrogen pressure in the second injection chamber 327 stabilizes. The tenth control valve 328 is then opened, driving the second piston 325 to move backward. The nitrogen gas in the second injection chamber 327 is then drawn into the second gas chamber 324 via the fourth connecting pipe 321. The tenth control valve 328, the second output terminal 812, and the third output terminal 813 are then closed. The eighth control valve 322, the first input terminal 811, and the fifth output terminal 815 are then opened, activating the constant speed and pressure pump. The second piston 325 is driven to move forward, and under the second preset pressure, the fourth connecting pipe 321 delivers nitrogen from the second gas chamber 324 to the first diffusion chamber 110. The above steps are repeated to detect the initial hydrogen concentration in the first diffusion chamber 110, the stable hydrogen concentration in the first diffusion chamber 110, the initial hydrogen concentration in the second diffusion chamber 130, and the stable hydrogen concentration in the second diffusion chamber 130. By changing different geological samples according to experimental needs, it is not necessary to conduct on-site tests on different types of geological structures, thus meeting the requirements for hydrogen diffusion testing on different types of geological structures. Furthermore, the diffusion coefficient and diffusion flux of hydrogen under different geological samples, gas concentrations, and temperature and pressure conditions are obtained. Based on the experimental data under the influence of multiple factors, a numerical simulation model of the hydrogen diffusion process is constructed, thereby systematically evaluating the leakage risk of hydrogen storage site selection under different operating conditions. This reduces the experimental time required for simulating the hydrogen diffusion characteristics of different types of geological structures, shortens the experimental time required for hydrogen storage site selection, improves the efficiency of hydrogen storage site selection, and provides reliable experimental data support for the sealing evaluation of underground hydrogen storage sites and the selection of hydrogen storage sites.

[0099] In this embodiment, the diffusion coefficient is calculated using the following formula:

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108] in, For hydrogen diffusion flux, The diffusion coefficient is... This represents the concentration of hydrogen gas in the geological sample. The length of the sample along the direction of hydrogen diffusion. The length of the geological sample. Let be the hydrogen concentration in the first diffusion chamber at time t. Let be the hydrogen concentration in the second diffusion chamber at time t. Let be the concentration difference between the first and second diffusion chambers at time t. The initial hydrogen concentration in the second diffusion chamber. The cross-sectional area of ​​the geological sample. Let V be the volume of the first diffusion chamber. Let V be the volume of the first diffusion chamber. For time.

[0109] The diffusion flux is calculated using the following formula:

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] in, Porosity The bending factor, For the effective diffusion coefficient, Hydrogen concentration, The length of the sample along the direction of hydrogen diffusion. The length of the geological sample. For time, The initial hydrogen concentration in the second diffusion chamber. For hydrogen diffusion flux, For the effective diffusion area, For diffusion flux.

[0116] The total diffusion amount is calculated using the following formula:

[0117]

[0118]

[0119] in, For the effective diffusion coefficient, The length of the geological sample. For time, The initial hydrogen concentration in the second diffusion chamber. For hydrogen diffusion flux, For the effective diffusion area, This represents the total diffusion amount of the hydrogen storage reservoir.

[0120] To achieve efficient design and safe operation of underground hydrogen storage facilities, multiple factors need to be comprehensively considered, including actual operating time, reservoir pressure, geological type, and gas concentration. A systematic calculation of the long-term diffusion flux of hydrogen under different conditions is required. Based on this, and with economy as the core guiding principle, the optimal combination of operating pressure and hydrogen concentration that meets both sealing safety requirements and good economic benefits is selected, thus providing a scientific basis for the engineering parameter design of the hydrogen storage facility.

[0121] The actual operating time of the hydrogen storage facility is the real time it takes from the start of formal hydrogen injection, storage, and extraction to the completion of a full operating cycle, while the reservoir pressure is the pressure of the geological structure.

[0122] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A hydrogen diffusion experimental apparatus, characterized in that, include: The core holder (100) has a first diffusion chamber (110), a sample chamber (120), and a second diffusion chamber (130) inside. The first diffusion chamber (110) and the second diffusion chamber (130) are respectively arranged on opposite sides of the sample chamber (120), and the sample chamber (120) is used to hold geological samples. A hydrogen supply mechanism (200) is connected to the second diffusion chamber (130) and is used to deliver hydrogen to the second diffusion chamber (130) under a first preset pressure. A first gas supply mechanism (300) is connected to the first diffusion chamber (110) and is used to deliver gas to the first diffusion chamber (110) under a second preset pressure. The detection mechanism (400) is connected to both the first diffusion chamber (110) and the second diffusion chamber (130), and is used to detect the gas concentration in the first diffusion chamber (110) and the second diffusion chamber (130).

2. The hydrogen diffusion experimental apparatus according to claim 1, characterized in that, The hydrogen supply mechanism (200) includes a hydrogen storage component (210) and a gas delivery component (220). The gas delivery component (220) is connected between the hydrogen storage component (210) and the second diffusion chamber (130). The hydrogen storage component (210) is used to store hydrogen gas, and the gas delivery component (220) is used to deliver the hydrogen gas stored in the hydrogen storage component (210) to the second diffusion chamber (130) under the first preset pressure.

3. The hydrogen diffusion experimental apparatus according to claim 1, characterized in that, The first gas supply mechanism (300) includes a first gas storage component (310) and a first conveying component (320). The first conveying component (320) is connected between the first gas storage component (310) and the first diffusion chamber (110). The first gas storage component (310) is used to store gas, and the first conveying component (320) is used to convey the gas stored in the first gas storage component (310) to the first diffusion chamber (110) under the second preset pressure.

4. The hydrogen diffusion experimental apparatus according to claim 1, characterized in that, It also includes a second gas supply mechanism (500) and a conveying mechanism (600), the second gas supply mechanism (500) being connected to the conveying mechanism (600), the conveying mechanism (600) being connected to the second diffusion chamber (130), the second gas supply mechanism (500) being used to deliver gas to the conveying mechanism (600) at a third preset pressure, the hydrogen supply mechanism (200) being used to deliver hydrogen to the conveying mechanism (600) or the second diffusion chamber (130) at a first preset pressure, and the conveying mechanism (600) being used to mix the gas from the second gas supply mechanism (500) and the hydrogen from the hydrogen supply mechanism (200) and deliver them to the second diffusion chamber (130).

5. The hydrogen diffusion experimental apparatus according to claim 4, characterized in that, The second gas supply mechanism (500) includes a second gas storage component (510) and a second conveying component (520). The second conveying component (520) is connected between the second gas storage component (510) and the conveying mechanism (600). The second gas storage component (510) is used to store gas, and the second conveying component (520) is used to convey the gas stored in the second gas storage component (510) to the conveying mechanism (600) under the third preset pressure.

6. The hydrogen diffusion experimental apparatus according to any one of claims 1-5, characterized in that, It also includes a pressure balancing mechanism (700) connected between the first diffusion chamber (110) and the second diffusion chamber (130), the pressure balancing mechanism (700) being used to adjust the pressure of the first diffusion chamber (110) and the second diffusion chamber (130) to be equal.

7. The hydrogen diffusion experimental apparatus according to claim 6, characterized in that, The pressure balancing mechanism (700) includes a cylinder (710) and a balancing piston (720). One end of the cylinder (710) is connected to the first diffusion chamber (110), and the other end of the cylinder (710) is connected to the second diffusion chamber (130). The balancing piston (720) is slidably connected inside the cylinder (710).

8. The hydrogen diffusion experimental apparatus according to claim 4, characterized in that, It also includes a pressure stabilizing mechanism (800), which is connected to the hydrogen supply mechanism (200), the first gas supply mechanism (300) and the second gas supply mechanism (500). The pressure stabilizing mechanism (800) is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism (200), the first gas supply mechanism (300) and the second gas supply mechanism (500), so that the hydrogen pressure in the hydrogen supply mechanism (200) is the first preset pressure, the gas pressure in the first gas supply mechanism (300) is the second preset pressure and the gas pressure in the second gas supply mechanism (500) is the third preset pressure.

9. The hydrogen diffusion experimental apparatus according to claim 8, characterized in that, The pressure stabilizing mechanism (800) includes an opening and closing element (810) and a constant pressure element (820). The opening and closing element (810) is connected to the hydrogen supply mechanism (200), the first gas supply mechanism (300), and the second gas supply mechanism (500). The constant pressure element (820) is connected to the opening and closing element (810). The opening and closing element (810) is used to connect at least one of the hydrogen supply mechanism (200), the first gas supply mechanism (300), and the second gas supply mechanism (500) with the constant pressure element (820). The constant pressure element (820) is used to maintain the gas pressure inside at least one of the hydrogen supply mechanism (200), the first gas supply mechanism (300), and the second gas supply mechanism (500) through the opening and closing element (810).

10. The hydrogen diffusion experimental apparatus according to any one of claims 1-5, characterized in that, It also includes a vacuuming mechanism (900) and a pressure simulation mechanism (930). The vacuuming mechanism (900) is connected to the core holder (100) and is used to evacuate the core holder (100) to make the core holder (100) a vacuum state. The pressure simulation mechanism (930) is connected to the core holder (100) and is used to apply pressure to the geological sample inside the core holder (100).

Images