Closed loop system apparatus and test method for hydrogen permeation testing under high pressure gas phase conditions

Abstract

The present application relates to hydrogen energy delivery test technical field, it is a kind of closed loop system device and test method for hydrogen permeation test under high-pressure gas phase condition, including the autoclave of hydrogen corrosion resistant material and closed loop pipe, autoclave includes kettle body and kettle cover, kettle body and closed loop pipe are communicated with each other, kettle body includes cylindrical section and conical flow guide section;Closed loop pipe includes vertical inlet section, U-shaped turn section, test section, backflow section in sequence along the anticlockwise direction setting;The present application successfully builds stable, continuous axial flow in test section by built-in stirring mechanism drive combination conical flow guide section, closed loop pipe integrated design, can form stable axial circulating flow, realize the true simulation of material hydrogen permeation behavior under pipe hydrogen working condition.Effectively overcome the problem of large deviation of flow pattern and real pipe transport working condition, make the flow state of sample surface more close to engineering practice, greatly improve the representativeness and accuracy of test result.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy transmission testing technology, and is a closed-loop system device and testing method for hydrogen permeation testing under high-pressure gas phase conditions. Background Technology

[0002] Hydrogen energy plays a crucial role in the low-carbon transformation of the energy structure, and how to safely transport hydrogen under high-pressure conditions has become a research hotspot. As the primary medium for hydrogen transport, the hydrogen permeation behavior of metal pipelines is critical to their operational safety.

[0003] To simulate the dynamic flow hydrogen permeation process in a hydrogen transport environment, two main experimental methods are currently used: one is a propeller-type device, which disturbs the gas inside the vessel by stirring the shaft to form a high-shear disturbance flow field on the sample surface. Although this type of device has a simple structure and can achieve a high gas flow velocity (>5m / s), the flow field generated by the propeller is mainly radial and vortex structure, lacking the axial development flow characteristics in a real pipeline. The flow is unstable, uncontrollable, and the gas flow direction is highly random. The flow field disturbance is severe, making it difficult to construct a typical boundary layer and concentration gradient (i.e., a typical hydrogen pipeline flow pattern). The permeation results have large deviations and poor repeatability. For example, patent application document CN115814702A discloses a propeller-type hydrogen permeation single-window high-pressure vessel.

[0004] Another type is the compressor-driven circulation system, which relies on external compression equipment to drive gas circulation and installs hydrogen permeation test samples at specific locations. These devices often employ pipeline circulation, easily forming laminar or turbulent flow structures, and the flow rate can be controlled by adjusting the compressor power. However, they are complex in structure, require high sealing, occupy a large area, and are cumbersome to debug and operate, making long-term operational reliability uncertain. Compression systems often inject gas through Y-tubes or abrupt transition structures, requiring a certain length of pipeline to ensure the gas flow fully develops into a stable flow pattern. For example, patent application CN116337709A discloses a high-pressure flow circulation hydrogen permeation test device and method.

[0005] Therefore, there is an urgent need to construct a hydrogen permeation testing device with a closed flow path, self-driving capability, axial flow dominance, controllable flow velocity, and adaptability to existing sample structures. Summary of the Invention

[0006] This invention provides a closed-loop system device and testing method for hydrogen permeation testing under high-pressure gas phase conditions, which can effectively solve the problems of strong randomness of airflow direction and large deviation of airflow pattern from typical hydrogen pipeline flow pattern when existing dynamic hydrogen permeation testing devices conduct hydrogen permeation experiments.

[0007] One of the technical solutions of this invention is achieved through the following measures: a closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions, comprising a high-pressure reactor made of hydrogen-resistant material and a closed-loop pipe. The high-pressure reactor includes a reactor body and a reactor lid, the reactor body and the closed-loop pipe being interconnected. The reactor body includes a cylindrical section and a conical guide section, arranged sequentially from top to bottom. The reactor lid is detachably installed on the top of the cylindrical section, and an inlet channel and an exhaust channel communicating with the interior of the reactor body are provided on the reactor lid; closed loop... The tube includes a vertical inlet section, a U-shaped bend section, a test section, and a reflux section arranged sequentially in a counterclockwise direction. The inner diameter or cross-sectional size of each section of the closed loop tube is the same. A reflux port is provided on the upper right side of the cylindrical section. The upper left end of the reflux section is connected to the reflux port. The upper end of the vertical inlet section is fixedly installed together with the lower end of the conical guide section. The test section has stepped mounting holes. A stirrer is fixedly installed on the vessel body. At least two blades are arranged at circumferential intervals at the lower end of the stirrer shaft. The blades are located inside the cylindrical section.

[0008] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:

[0009] Furthermore, the cone angle of the aforementioned conical guide section is 60°.

[0010] Furthermore, the power angle of the aforementioned blades is 35°.

[0011] Furthermore, the cross-section of the entire closed-loop tube is square.

[0012] Furthermore, the aforementioned reflux section includes an arc-shaped buffer section and a horizontal section, which are arranged sequentially in a counterclockwise direction. The left end of the horizontal section is connected to the reflux port, and the lower right end of the arc-shaped buffer section is fixedly connected to the upper end of the test section.

[0013] Furthermore, the aforementioned hydrogen corrosion resistant material is 316L stainless steel.

[0014] Furthermore, the aforementioned agitator includes a motor and a stirring shaft. The power output shaft of the motor is connected to the upper part of the stirring shaft. An axial mounting hole is provided in the center of the vessel cover. The stirring shaft extends into the vessel body through the axial mounting hole. Three blades are arranged at intervals along the circumference at the lower end of the stirring shaft.

[0015] Furthermore, the top of the cylindrical section is fixedly fitted with a vessel lid via a flange, and a sealing element is provided between the top of the flange and the bottom of the vessel lid.

[0016] Furthermore, the upper end of the aforementioned vertical inlet section and the lower end of the conical guide section are fixedly installed together by a flange.

[0017] The second technical solution of the present invention is achieved through the following measures: a test method for a closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions, comprising:

[0018] Sample installation: Securely install the sample into the mounting hole of the test section, insert the auxiliary electrode and reference electrode into the electrolytic cell of the transition tube, and form a stable electrochemical circuit interface between the auxiliary electrode, reference electrode and sample cavity. The sample cavity serves as the working electrode, and the auxiliary electrode and reference electrode are connected to the electrochemical workstation via quick-connect cables.

[0019] Hydrogen permeation test:

[0020] First, the air inside the reactor is replaced through the air intake and exhaust channels. After the current measured by the potentiostat of the electrochemical workstation stabilizes, hydrogen is then introduced into the reactor until the pressure inside the reactor stabilizes at the set pressure value. Then, static hydrogen permeation test and dynamic cyclic hydrogen permeation test are carried out respectively.

[0021] The following are further optimizations and / or improvements to the second technical solution of the above invention:

[0022] Furthermore, the aforementioned static hydrogen permeation test specifically includes:

[0023] A constant anodic polarization potential is applied to the sample using an electrochemical workstation, and the curve of the permeation current flowing through the sample changing over time is continuously measured and recorded. This test continues until the recorded current value reaches a steady state, thus obtaining the reference hydrogen permeation current data of the sample under high-pressure static hydrogen environment.

[0024] Furthermore, the aforementioned dynamic cyclic hydrogen permeation test specifically includes:

[0025] Step 1: Start the stirrer. First, set the speed of the stirrer motor to n to drive the gas to start circulating in the closed loop tube to form an initial flow field. After the flow field stabilizes, apply the same anodic polarization potential through the electrochemical workstation and record the hydrogen permeation current-time curve at the gas flow rate corresponding to the speed n.

[0026] Step 2: While keeping the pressure constant, readjust the rotation speed, and repeat the process described in Step 1 above by applying the same anodic polarization potential through the electrochemical workstation at each constant rotation speed, and record the hydrogen permeation current-time curve at the gas flow rate corresponding to the rotation speed, thereby obtaining a series of hydrogen permeation current-time curves corresponding to different gas flow rates.

[0027] The beneficial effects of this invention are:

[0028] (1) Realistic and controllable axial flow field simulation: This invention, through the integrated design of a built-in stirring mechanism (including stirring shaft and blades) combined with a conical guide section and a closed-loop pipe, successfully constructs a stable and continuous axial flow in the test section, forming a stable axial circulating flow, thus realizing a realistic simulation of the hydrogen permeation behavior of materials under pipeline hydrogen transportation conditions. This is fundamentally different from the random vortex flow field generated by traditional propeller stirring devices (described in patent application document CN115814702A), effectively overcoming the problem of large deviation between the flow pattern and the actual pipeline transportation conditions, making the flow state on the sample surface closer to engineering reality, and greatly improving the representativeness and accuracy of the test results.

[0029] (2) The system has a compact structure, high safety, and reliable operation: This invention abandons the complex and cumbersome external compression circulation system (described in patent application CN116337709A) and adopts a built-in self-driven mode (i.e., a stirrer). The entire device has a compact structure, small footprint, and few sealing points, which are concentrated in the static sealing of the vessel body and the static sealing of the sample, significantly reducing the risk of high-pressure hydrogen leakage. The system has no exposed high-speed rotating parts and clear boundaries, making it very suitable for long-term, continuous high-pressure hydrogen permeation testing in a laboratory environment, fundamentally improving safety and reliability.

[0030] (3) Minimal flow field disturbance and good test repeatability: Thanks to the embedded stepped sample structure and its flush installation with the inner wall of the pipe (as described in patent application CN120609725A), this invention completely avoids the flow field disturbance, boundary layer separation, and eddy current phenomena caused by the protrusions formed in the flow channel by traditional fixtures. Simulations and experiments have confirmed that this design can ensure that hydrogen forms a uniform and stable high-shear flow on the sample surface, providing highly consistent boundary conditions for hydrogen permeation testing, thereby significantly improving the repeatability and comparability of experimental data.

[0031] (4) Precisely adjustable flow rate and wide operating condition coverage: By steplessly adjusting the motor speed (0 to 1500 rpm), the gas flow rate in the closed-loop tube can be conveniently and precisely controlled to continuously vary within the range of 1.0 to 1.5 m / s. This allows a single device to complete hydrogen permeation tests from static (0 rpm) to various dynamic flow rate conditions, facilitating systematic research on the influence of flow rate, a key parameter, on the hydrogen permeation behavior of materials, and providing strong operating condition simulation capabilities.

[0032] (5) Modular and versatile design with strong expandability: The test section of this device can adopt standardized flange interfaces and modularly designed sample installation components, making sample loading, unloading, and replacement quick and convenient. This structure is not only compatible with the sample described in this invention, but can also be used with various existing standard hydrogen permeation test samples, demonstrating good versatility. At the same time, this closed-loop system is easy to integrate with other external systems (such as corrosion solution injection systems, erosion devices, etc.), providing the possibility to carry out more complex multiphase flow coupled corrosion-hydrogen permeation tests and possessing strong functional expandability. Attached Figure Description

[0033] Appendix Figure 1 This is a schematic diagram of a partial cross-sectional view of a closed-loop system device used for hydrogen permeation testing under high-pressure gas phase conditions.

[0034] Appendix Figure 2 This is a velocity field diagram from a simulation test.

[0035] Appendix Figure 3 This is a streamline diagram for simulation testing.

[0036] The codes in the attached diagram are as follows: 1 is the vessel lid, 2 is the cylindrical section, 3 is the conical guide section, 4 is the air inlet channel, 5 is the vertical inlet section, 6 is the U-shaped bend section, 7 is the test section, 8 is the reflux port, 9 is the stirring shaft, 10 is the impeller, 11 is the nut, 12 is the arc-shaped buffer section, 13 is the horizontal section, 14 is the transition pipe, 15 is the electrolytic cell, 16 is the auxiliary electrode socket, 17 is the reference electrode socket, 18 is the sample, and 19 is the drain hole. Detailed Implementation

[0037] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0038] For ease of description, the relative positions of the components are described based on the appendix to the instruction manual. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0039] In this invention, the closed-loop system device described below refers to the closed-loop system device of this invention used for hydrogen permeation testing under high-pressure gas phase conditions.

[0040] Mechanical seals, also known as face seals, are devices that achieve sealing by sliding end faces perpendicular to the axis of rotation. They are primarily used to prevent fluid leakage. The core components of a mechanical seal assembly include a rotating ring (made of tungsten carbide), a stationary ring (made of resin-impregnated graphite), an elastic element (a metal spring or a metal bellows), and auxiliary sealing rings (O-rings, gaskets).

[0041] In this invention, the specific structure of the mounting hole of test section 7 and the structure of sample 18 are described in the patent application document CN120609725A entitled "Test Structure for Hydrogen Permeation Testing in High Pressure Gas Phase Hydrogen Environment and its Installation Method and Application". The installation method and sealing method of sample 18 described in this invention are performed in accordance with the installation method and sealing method of sample body described in the patent application document.

[0042] In this invention, the test surface of sample 18 refers to the sample surface exposed to a hydrogen environment.

[0043] Power angle: The angle between the blade 10 and the horizontal plane.

[0044] The present invention will be further described below with reference to embodiments:

[0045] Example 1: As Figure 1 As shown, a closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions includes a high-pressure autoclave made of hydrogen-resistant material and a closed-loop pipe. The autoclave includes an autoclave body and an autoclave cover 1, which are connected to each other. The autoclave body includes a cylindrical section 2 and a conical guide section 3, which are arranged sequentially from top to bottom. The autoclave cover 1 is detachably installed on the top of the cylindrical section 2. An air inlet channel 4 and an exhaust channel communicating with the interior of the autoclave body are provided on the autoclave cover 1. The closed-loop pipe includes a closed-loop pipe arranged sequentially in a counterclockwise direction. The cylindrical section 2 is equipped with a vertical inlet section 5, a U-shaped bend section 6, a test section 7, and a reflux section. The inner diameter or cross-sectional size of each section of the closed loop pipe is the same. A reflux port 8 is provided on the upper right side of the cylindrical section 2. The upper left end of the reflux section is connected to the reflux port 8. The upper end of the vertical inlet section 5 is fixedly installed with the lower end of the conical guide section 3. The test section 7 has stepped mounting holes. A stirrer is fixedly installed on the vessel body. At least two blades 10 are arranged at intervals along the circumference at the lower end of the stirring shaft 9 of the stirrer. The blades 10 are located inside the cylindrical section 2.

[0046] The vessel body and the closed-loop pipe together form a closed gas circulation path. The conical guide section 3 is used to guide the gas smoothly into the subsequent closed-loop pipe. The U-shaped turning section 6 is used to achieve a smooth 180° turn of the gas from the vertical inlet section 5 to the test section 7, so as to reduce local flow resistance and eddy current generation.

[0047] Test section 7 is the core area for hydrogen permeation testing. The reflux section guides the gas back into the vessel, completing the entire closed-loop gas circulation. The inlet channel 4 and the exhaust channel are used for gas intake and exhaust. The vessel cover 1 can be installed on the top of the cylindrical section 2 using fasteners, which can be nuts 11 and bolts, or other existing and commonly known fasteners.

[0048] Patent application CN116337709A, entitled "A High-Pressure Flow Cyclic Hydrogen Permeation Test Apparatus and Method," describes a test specimen 18 installed on the side wall of a vessel. The upper and lower ends of the vessel are connected to an upper pipe section and a lower pipe section, respectively, with inner diameters smaller than the vessel's inner diameter. This test section (including the vessel, upper pipe section, and lower pipe section) structure constitutes a variable-diameter pipe, which leads to significant gas retention within the vessel during cyclic hydrogen permeation testing. This results in inconsistent gas scouring of the specimen surface. The present invention solves this gas retention problem by ensuring that the inner diameter or cross-sectional size of each section of the closed-loop pipe is consistent, allowing the test surface of the specimen to be completely in contact with the gas scouring environment.

[0049] Compared to traditional propeller-driven agitators and compressor-driven open-loop systems, the closed-loop system provided by this invention eliminates the need for a high-pressure external compressor. Driven internally by the agitator, it features a compact structure, clear boundaries, and high safety, making it suitable for long-term testing. Through the kinetic energy conversion of the agitator and the design of the conical guide section 3, a stable and continuous axial flow field can be constructed, making the hydrogen flow on the test surface of sample 18 more closely resemble real-world engineering conditions, significantly improving the representativeness and repeatability of dynamic hydrogen permeation testing. The flow rate is adjustable, the flow pattern is controllable, and it can be compatible with various existing sample standards, exhibiting excellent modular scalability.

[0050] Example 2: As an optimization of the above embodiment, if necessary, in order to further guide the gas smoothly into the subsequent closed loop pipe, the cone angle of the cone guide section 3 is 60°.

[0051] Example 3: As an optimization of the above embodiment, the power angle of the impeller 10 is 35°. Under low-speed, high-torque driving conditions, the power angle setting enables the impeller 10 to effectively capture and axially push low-density gases (such as hydrogen), generating high circulation flow and sufficient pressure head to overcome system resistance and achieve excellent gas mass transfer effect inside the vessel.

[0052] Example 4: As an optimization of the above embodiment, in order to facilitate the installation of sample 18 at test section 7 and the installation of reflux section at reflux port 8, the cross-section of the entire closed loop tube is square.

[0053] Example 5: As an optimization of the above embodiments, such as Figure 1 As shown, the recirculation section includes an arc-shaped buffer section 12 and a horizontal section 13. The arc-shaped buffer section 12 and the horizontal section 13 are arranged sequentially in a counterclockwise direction. The left end of the horizontal section 13 is connected to the recirculation port 8, and the lower right end of the arc-shaped buffer section 12 is fixedly connected to the upper end of the test section 7.

[0054] Example 6: As an optimization of the above embodiment, the hydrogen corrosion resistant material is 316L stainless steel as needed.

[0055] Example 7: As an optimization of the above embodiment, as needed, the stirrer includes a motor and a stirring shaft 9. The power output shaft of the motor is connected to the upper part of the stirring shaft 9. An axial mounting hole is opened in the center of the lid 1. The stirring shaft 9 extends into the body of the lid through the axial mounting hole. Three blades 10 are arranged at intervals along the circumference at the lower end of the stirring shaft 9.

[0056] The motor can be fixedly supported by a bracket. Driven by the motor, the impeller 10 rotates, efficiently transferring kinetic energy to the gas medium, providing the core power for the gas medium to circulate in the closed-loop tube. The gas medium then flows to the conical guide section 3. A conventional mechanical seal assembly can be integrated into the axial mounting hole to secure and seal the stirring shaft 9.

[0057] The purpose of positioning the blade 10 in the cylindrical section 2 is to provide kinetic energy to the gas medium while minimizing the interference of the blade 10's rotation on the flow behavior of the gas medium in other structural sections. For example, it can both maintain the kinetic energy concentration effect of the gas medium in the conical guide section 3 and avoid the local strong shearing of the blade 10 from disturbing the flow field of the test surface of the sample 18 in the test section 7.

[0058] Example 8: As an optimization of the above embodiment, if necessary, a vessel cover 1 is fixedly installed on the top of the cylindrical section 2 via a flange, and a sealing element is provided between the top of the flange and the bottom of the vessel cover 1. The sealing element can be a sealing ring made of hydrogen corrosion resistant material.

[0059] Example 9: As an optimization of the above embodiment, if necessary, the upper end of the vertical inlet section 5 and the lower end of the conical guide section 3 are fixedly installed together by a flange. The upper end of the vertical inlet section 5 and the lower end of the conical guide section 3 can also be fixedly connected together by welding. The upper left end of the return section can be fixedly connected to the return port 8 by welding.

[0060] Example 10: As Figure 1 As shown, a test method for a closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions includes:

[0061] Sample 18 Installation: Securely install sample 18 into the mounting hole of test section 7. Insert the auxiliary electrode and reference electrode into the electrolytic cell 15 of transition tube 14. The auxiliary electrode, reference electrode, and sample cavity form a stable electrochemical circuit interface. The sample cavity serves as the working electrode. The auxiliary electrode and reference electrode are connected to the electrochemical workstation via quick-connect cables. The auxiliary electrode is a high-purity graphite electrode, the reference electrode is an Hg / HgO electrode, and the electrolyte in electrolytic cell 15 is a sodium hydroxide solution. The auxiliary electrode is inserted into electrolytic cell 15 through auxiliary electrode insertion hole 16, and the reference electrode is inserted into electrolytic cell 15 through reference electrode insertion hole 17. The sample cavity is described in patent application document (CN120609725A).

[0062] Hydrogen permeation test:

[0063] First, the air inside the vessel is replaced through the air inlet channel 4 and the exhaust channel to remove the residual gas inside the vessel. This process is repeated three times. After the current measured by the potentiostat of the electrochemical workstation stabilizes, hydrogen is then introduced into the vessel until the pressure inside the vessel stabilizes at the set pressure value. Then, static hydrogen permeation test and dynamic cyclic hydrogen permeation test are carried out respectively.

[0064] The static hydrogen permeation test specifically includes:

[0065] A constant anodic polarization potential (e.g., +300 mV relative to the Hg / HgO reference electrode) is applied to sample 18 using an electrochemical workstation, and the curve of the permeation current flowing through sample 18 over time is continuously measured and recorded. This test continues until the recorded current value reaches a steady state, thus obtaining the reference hydrogen permeation current data of sample 18 under high-pressure static hydrogen environment, such as hydrogen permeation current, hysteresis time, and apparent diffusion coefficient.

[0066] The dynamic cyclic hydrogen permeation test specifically includes:

[0067] Step 1: Start the stirrer and set the motor speed of the stirrer to n (e.g., 500 rpm) to drive the gas to circulate in the closed loop tube to form an initial flow field. After the flow field stabilizes, apply the same anodic polarization potential through the electrochemical workstation and record the hydrogen permeation current-time curve at the gas flow rate corresponding to the speed n to study the effect of different shear flow rates on hydrogen permeation behavior.

[0068] Step 2: While maintaining constant pressure, the rotation speed is adjusted sequentially (the motor speed is adjusted to 1000 rpm and 1500 rpm). At each constant rotation speed, the same anodic polarization potential is applied through the electrochemical workstation as described in Step 1, and the hydrogen permeation current-time curves at the gas flow rate corresponding to the rotation speed are recorded. This yields a series of hydrogen permeation current-time curves corresponding to different gas flow rates, which constitute a dynamic hydrogen permeation curve.

[0069] After the experiment, the electrolyte was discharged through the drain hole 19.

[0070] A dynamic cyclic hydrogen permeation test simulation experiment was conducted according to the method described in Example 10. The simulation results show that, as Figure 2 and Figure 3As shown, this closed-loop system can achieve a stable axial flow with a velocity of 1.2 m / s to 1.5 m / s in test section 7 at a propeller speed of 1500 rpm, with a local jet velocity of 2 m / s to 2.5 m / s, meeting the typical flow pattern and boundary layer requirements of hydrogen pipelines, and is suitable for high-pressure gas-phase dynamic circulating hydrogen permeation testing.

[0071] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions, characterized in that, The system includes a high-pressure reactor made of hydrogen-resistant materials and a closed-loop pipe. The high-pressure reactor comprises a reactor body and a reactor lid, with the reactor body and the closed-loop pipe connected to each other. The reactor body includes a cylindrical section and a conical guide section, arranged sequentially from top to bottom. The reactor lid is detachably installed on the top of the cylindrical section, and the lid has an inlet channel and an exhaust channel communicating with the interior of the reactor body. The closed-loop pipe includes a vertical inlet section, a U-shaped bend section, a test section, and a reflux section arranged sequentially in a counterclockwise direction. The inner diameter or cross-sectional size of each section of the closed-loop pipe is the same. The right side of the cylindrical section... A reflux port is provided on the upper side, and the upper left end of the reflux section is connected to the reflux port. The upper end of the vertical inlet section is fixedly installed together with the lower end of the conical guide section. The test section has stepped mounting holes. A stirrer is fixedly installed on the vessel body. At least two blades are arranged at intervals along the circumference at the lower end of the stirrer shaft. The blades are located inside the cylindrical section. The reflux section includes an arc-shaped buffer section and a horizontal section. The arc-shaped buffer section and the horizontal section are arranged in sequence in a counterclockwise direction. The left end of the horizontal section is connected to the reflux port, and the lower right end of the arc-shaped buffer section is fixedly connected to the upper end of the test section.

2. The closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions according to claim 1, characterized in that, The cone angle of the conical guide section is 60°; or / and, the power angle of the blade is 35°; or / and, the cross-section of the entire closed loop pipe is square.

3. The closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions according to claim 1 or 2, characterized in that, The hydrogen corrosion resistant material is 316L stainless steel; or / and, the agitator includes a motor and an agitator shaft, the power output shaft of the motor is connected to the upper part of the agitator shaft, an axial mounting hole is opened in the center of the vessel cover, the agitator shaft extends into the vessel body through the axial mounting hole, and three blades are arranged at intervals along the circumference at the lower end of the agitator shaft.

4. The closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions according to claim 1 or 2, characterized in that, The top of the cylindrical section is fixedly fitted with a vessel lid via a flange, and a sealing element is provided between the top of the flange and the bottom of the vessel lid; Alternatively, the upper end of the vertical inlet section and the lower end of the conical guide section are fixed together by a flange.

5. The closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions according to claim 3, characterized in that, The top of the cylindrical section is fixedly fitted with a vessel lid via a flange, and a sealing element is provided between the top of the flange and the bottom of the vessel lid; Alternatively, the upper end of the vertical inlet section and the lower end of the conical guide section are fixed together by a flange.

6. A test method for a closed-loop system device for hydrogen permeation testing under high-pressure gas phase conditions according to any one of claims 1 to 5, characterized in that, include: Sample installation: Securely install the sample into the mounting hole of the test section, insert the auxiliary electrode and reference electrode into the electrolytic cell of the transition tube, and form a stable electrochemical circuit interface between the auxiliary electrode, reference electrode and sample cavity. The sample cavity serves as the working electrode, and the auxiliary electrode and reference electrode are connected to the electrochemical workstation via quick-connect cables. Hydrogen permeation test: First, the air inside the reactor is replaced through the air intake and exhaust channels. After the current measured by the potentiostat of the electrochemical workstation stabilizes, hydrogen is then introduced into the reactor until the pressure inside the reactor stabilizes at the set pressure value. Then, static hydrogen permeation test and dynamic cyclic hydrogen permeation test are carried out respectively.

7. The test method according to claim 6, characterized in that, Static hydrogen permeation testing specifically includes: A constant anodic polarization potential is applied to the sample using an electrochemical workstation, and the curve of the permeation current flowing through the sample changing over time is continuously measured and recorded. This test continues until the recorded current value reaches a steady state, thus obtaining the reference hydrogen permeation current data of the sample under high-pressure static hydrogen environment.

8. The test method according to claim 6 or 7, characterized in that, Dynamic cyclic hydrogen permeation testing specifically includes: Step 1: Start the stirrer. First, set the speed of the stirrer motor to n to drive the gas to start circulating in the closed loop tube to form an initial flow field. After the flow field stabilizes, apply the same anodic polarization potential through the electrochemical workstation and record the hydrogen permeation current-time curve at the gas flow rate corresponding to the speed n. Step 2: While keeping the pressure constant, readjust the rotation speed, and repeat the process described in Step 1 above by applying the same anodic polarization potential through the electrochemical workstation at each constant rotation speed, and record the hydrogen permeation current-time curve at the gas flow rate corresponding to the rotation speed, thereby obtaining a series of hydrogen permeation current-time curves corresponding to different gas flow rates.

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