A high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling

Abstract

The utility model provides a kind of high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling, including with the sample (31) of high-pressure hydrogen supply gas path end's hydrogen measuring box (18) is connected, gas source, gas booster (7), buffer tank (10), autoclave (13) are sequentially arranged at high-pressure hydrogen supply gas path;The sample is placed at the hydrogen permeation surface of autoclave;Buffer tank is wrapped for heating first heat transfer jacket (9);Autoclave is wrapped for heating second heat transfer jacket (14), external electrochemical workstation (19) is connected by electrode with hydrogen measuring box, sample;The utility model can solve the problem that three key variables of pressure, temperature and stress cannot be controlled simultaneously in existing test technology, provide a kind of can simulate real pure hydrogen or hydrogen-doped service environment, and can accurately measure the hydrogen permeation performance of metal material under pressure-temperature-stress coupling.

Description

Technical Field

[0001] This utility model relates to the technical field of hydrogen permeation testing equipment, and in particular to a high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling. Background Technology

[0002] In high-pressure pure hydrogen or hydrogen-blended natural gas environments, hydrogen-contaminated equipment and metallic materials are prone to hydrogen embrittlement, leading to reduced material plasticity, crack initiation, and even eventual failure. Hydrogen permeation kinetic parameters of metallic materials in high-pressure hydrogen environments (such as hydrogen diffusion coefficient, surface adsorbed hydrogen concentration, and hydrogen solubility) are key indicators for evaluating their hydrogen permeation resistance and guiding material selection in practical engineering. Currently, most commonly used hydrogen permeation testing methods are conducted under ambient temperature and pressure or single-variable conditions, making it difficult to realistically simulate the coupling effect between temperature, stress, and hydrogen pressure under high-pressure pure hydrogen or hydrogen-blended natural gas conditions. Furthermore, traditional dual-electrolysis cell hydrogen permeation testing techniques cannot simultaneously apply stress during the test. Therefore, there is an urgent need to develop a testing device capable of simultaneously and precisely controlling pressure, temperature, and stress, and monitoring hydrogen permeation flux in real time, to accurately assess the hydrogen permeation behavior of materials in actual service environments. Utility Model Content

[0003] This invention proposes a high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling, which can solve the problem that existing testing technologies cannot simultaneously control the three key variables of pressure, temperature and stress. It provides a high-pressure hydrogen permeation testing device that can simulate the real pure hydrogen or hydrogen-doped service environment and accurately measure the gas diffusion performance of metal materials under equilibrium conditions under high pressure.

[0004] The present invention adopts the following technical solution.

[0005] A high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling, the testing device includes a hydrogen measuring box (18) connected to a sample (31) at the end of a high-pressure hydrogen supply line, wherein a gas source, a gas booster (7), a buffer tank (10), and a high-pressure vessel (13) are sequentially arranged at the high-pressure hydrogen supply line; the sample is placed at the hydrogen permeation surface of the high-pressure vessel; a first heat transfer jacket (9) for heating is wrapped around the buffer tank; a second heat transfer jacket (14) for heating is wrapped around the high-pressure vessel; and an external electrochemical workstation (19) is connected to the hydrogen measuring box and the sample through electrodes.

[0006] The hydrogen measuring box contains an internal electrolyte, and the external electrochemical workstation (19) is connected to the hydrogen measuring box and the sample via wires, working electrode (15), reference electrode (16), and auxiliary electrode (17) to monitor and collect hydrogen permeation current. When hydrogen or hydrogen-doped gas is supplied to the sample from the high-pressure hydrogen supply line, causing hydrogen permeation at the sample, the hydrogen atoms that permeate into the hydrogen measuring cell are ionized under the constant potential of the electrochemical workstation to produce hydrogen ions and electrons, thereby forming a hydrogen permeation current. The changes in the hydrogen permeation current are monitored and data is collected.

[0007] The gas source includes a high-pressure nitrogen cylinder (1), a high-pressure methane cylinder (2), and a high-pressure hydrogen cylinder (3). The high-pressure nitrogen cylinder (1), the high-pressure methane cylinder (2), and the high-pressure hydrogen cylinder (3) are connected to a gas booster via a first pipe, a second pipe, and a third pipe, respectively, to form a booster system. The gas booster pressurizes the hydrogen or hydrogen-blended gas output from the gas source to form test gas, and then inputs the test gas into a buffer tank via a fourth pipe.

[0008] The first, second, and third pipes are respectively equipped with a first shut-off valve (4), a second shut-off valve (5), and a third shut-off valve (6), and the fourth pipe is equipped with a fourth shut-off valve (8).

[0009] The first heat transfer jacket and the second heat transfer jacket are connected to a high-precision temperature control device (21) to adjust and maintain the temperature of the test gas in the buffer tank and the autoclave within a preset range.

[0010] The high-precision temperature control device is connected to the first and second heat transfer jackets via pipelines to form a temperature control system. The temperature control system regulates and maintains the temperature of the test gas in the buffer tank and the autoclave by circulating and heating the medium in the pipelines and jackets.

[0011] The surface of the sample is covered with strain gauges that are connected to the loading nut (29).

[0012] The loading nut is equipped with a dial gauge (28) for measuring the loading displacement. When the stress applied to the specimen by the strain gauge is adjusted by rotating the loading nut, the loading displacement measured by the dial gauge can be used to calculate the stress and plot the stress-loading displacement curve.

[0013] The high-pressure vessel and the hydrogen measuring box form a hydrogen permeation system; the high-pressure vessel has an inlet (22) and an outlet (23), and hydrogen or hydrogen-doped gas enters the interior of the high-pressure vessel through the inlet to undergo hydrogen permeation.

[0014] The lower end of the autoclave is connected to a first channel (24) and a second channel (25) arranged in sequence. The second channel is connected to a hydrogen measuring box containing electrolyte. The width of the first channel is greater than that of the second channel. The first channel and the second channel are located between the autoclave and the hydrogen measuring box. The gap between the two channels forms a placement cavity for placing the sample. The sample is connected to the working electrode (15). Porous metal filters (26) are provided at the upper and lower ends of the sample to form a separation structure between the first channel and the second channel.

[0015] This invention proposes a device for accurately measuring the gas permeability of metallic materials under high pressure in equilibrium under controllable pressure, temperature, and stress conditions. It ensures the reliability of measurement data while accurately measuring the permeation area and distance, preventing gas leakage, and maintaining gas stability. Therefore, it can successfully obtain the hydrogen diffusion coefficient, surface adsorbed hydrogen concentration, and hydrogen solubility from the test data. The accuracy and reliability of these data are essential for assessing the safety of metallic materials. This not only helps in selecting suitable metallic materials for practical applications in high-pressure hydrogen environments but also helps in analyzing the influence of the physical properties of metallic materials used in hydrogen-doped pipelines under high pressure on hydrogen permeability.

[0016] This invention enables the synchronous adjustment of pressure, temperature, and stress, and provides reliable experimental technical support for accurately measuring the hydrogen permeation behavior of metallic materials under high pressure in equilibrium. It also provides a practical and effective solution for simulating the service environment of real hydrogen-doped pipelines and screening suitable metallic materials. Attached Figure Description

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Appendix Figure 1 This is a schematic diagram of the testing device; Appendix Figure 2 This is a schematic diagram of the internal structure of the autoclave and the hydrogen measurement side components; In the diagram: 1-High-pressure nitrogen cylinder; 2-High-pressure methane cylinder; 3-High-pressure hydrogen cylinder; 4-First shut-off valve; 5-Second shut-off valve; 6-Third shut-off valve; 7-Gas booster; 8-Fourth shut-off valve; 9-First heat transfer jacket; 10-Buffer tank; 11-Pressure gauge; 12-Fifth shut-off valve; 13-High-pressure reactor; 14-Second heat transfer jacket; 15-Working electrode; 16-Reference electrode; 17-Auxiliary electrode; 18-Hydrogen measuring box; 19-Electrochemical workstation; 20-Data acquisition computer; 21-High-precision temperature control device; 22-Gas inlet; 23-Gas outlet; 24-First channel; 25-Second channel; 26-Porous metal filter; 27-O-ring; 28-Dial gauge; 29-Loading nut; 30-Anchor; 31-Sample. Detailed Implementation

[0018] As shown in the figure, a high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling is provided. The testing device includes a hydrogen measuring box 18 connected to a sample 31 at the end of a high-pressure hydrogen supply line. A gas source, a gas booster 7, a buffer tank 10, and an autoclave 13 are sequentially arranged at the high-pressure hydrogen supply line. The sample is placed at the hydrogen permeation surface of the autoclave. A first heat transfer jacket 9 for heating is wrapped around the buffer tank. A second heat transfer jacket 14 for heating is wrapped around the autoclave. An external electrochemical workstation 19 is connected to the hydrogen measuring box and the sample through electrodes.

[0019] The hydrogen measuring box contains an internal electrolyte, and the external electrochemical workstation 19 is connected to the hydrogen measuring box and the sample via wires, working electrode 15, reference electrode 16, and auxiliary electrode 17 to monitor and collect hydrogen permeation current. When hydrogen or hydrogen-doped gas is supplied to the sample from the high-pressure hydrogen supply line, causing hydrogen permeation at the sample, the hydrogen atoms that permeate into the hydrogen measuring cell are ionized under the constant potential of the electrochemical workstation to produce hydrogen ions and electrons, thereby forming a hydrogen permeation current. The changes in the hydrogen permeation current are monitored and data is collected.

[0020] The gas source includes a high-pressure nitrogen cylinder 1, a high-pressure methane cylinder 2, and a high-pressure hydrogen cylinder 3. The high-pressure nitrogen cylinder 1, high-pressure methane cylinder 2, and high-pressure hydrogen cylinder 3 are connected to a gas booster via a first pipe, a second pipe, and a third pipe, respectively, to form a booster system. The gas booster pressurizes the hydrogen or hydrogen-blended gas output from the gas source to form a test gas, which is then fed into a buffer tank via a fourth pipe.

[0021] The first, second, and third pipes are respectively equipped with a first shut-off valve 4, a second shut-off valve 5, and a third shut-off valve 6, and the fourth pipe is equipped with a fourth shut-off valve 8.

[0022] The first heat transfer jacket and the second heat transfer jacket are connected to the high-precision temperature control device 21 to adjust and maintain the temperature of the test gas in the buffer tank and the autoclave within a preset range.

[0023] The high-precision temperature control device is connected to the first and second heat transfer jackets via pipelines to form a temperature control system. The temperature control system regulates and maintains the temperature of the test gas in the buffer tank and the autoclave by circulating and heating the medium in the pipelines and jackets.

[0024] The surface of the sample is covered with strain gauges that are connected to the loading nut 29.

[0025] The loading nut is equipped with a dial gauge 28 for measuring the loading displacement. When the stress applied to the specimen by the strain gauge is adjusted by rotating the loading nut, the loading displacement measured by the dial gauge can be used to calculate the stress and plot the stress-loading displacement curve.

[0026] The high-pressure vessel and the hydrogen measuring box form a hydrogen permeation system; the high-pressure vessel has an inlet 22 and an outlet 23, and hydrogen or hydrogen-doped gas enters the interior of the high-pressure vessel through the inlet to undergo hydrogen permeation.

[0027] The lower end of the autoclave is connected to a first channel 24 and a second channel 25 arranged in sequence. The second channel is connected to a hydrogen measuring box containing electrolyte. The width of the first channel is greater than that of the second channel. The first and second channels are located between the autoclave and the hydrogen measuring box. The gap between the two channels forms a placement cavity for placing the sample. The sample is connected to the working electrode 15. Porous metal filters 26 are provided at the upper and lower ends of the sample to form a separation structure between the first and second channels.

[0028] Example 1: like Figures 1 to 2 This invention provides a high-pressure hydrogen permeation testing device with controllable pressure, temperature, and stress. The experimental device includes a pressurization system, a temperature control system, and a hydrogen permeation system. The pressurization system includes a high-pressure nitrogen cylinder 1, a high-pressure methane cylinder 2, a high-pressure hydrogen cylinder 3, a gas booster 7, and a buffer tank 10. The high-pressure nitrogen cylinder 1, high-pressure methane cylinder 2, and high-pressure hydrogen cylinder 3 are respectively connected to the gas booster 7 via first, second, and third pipes, with a first shut-off valve 4, a second shut-off valve 5, and a third shut-off valve 6 respectively installed on the first, second, and third pipes. The gas booster 7 is connected to the buffer tank 10 via a fourth pipe, with a fourth shut-off valve 8 installed on the fourth pipe. The gas booster 7 can pressurize hydrogen or hydrogen-blended gas from the high-pressure nitrogen cylinder 1, high-pressure methane cylinder 2, and high-pressure hydrogen cylinder 3 for subsequent testing. The buffer tank 10 is used to temporarily store the high-pressure hydrogen or hydrogen-blended gas. The temperature control system includes a first heat transfer jacket 9, a second heat transfer jacket 14, and a high-precision temperature control device 21. The first heat transfer jacket 9 surrounds the buffer tank 10, and the second heat transfer jacket 14 surrounds the autoclave 13. The first heat transfer jacket 9 and the second heat transfer jacket 14 are connected to the high-precision temperature control device 21 via pipelines. The high-precision temperature control device 21 regulates and maintains the temperature of the test gas in the buffer tank 10 and the autoclave 13 within a preset range by cyclically heating the medium in the first heat transfer jacket 9 and the second heat transfer jacket 14. The hydrogen permeation system includes an autoclave 13 and a hydrogen measuring box 18. The autoclave 13 has an inlet 22 and an outlet 23. Hydrogen or hydrogen-doped gas enters the autoclave 13 through the inlet 22 and undergoes hydrogen permeation. The lower end of the autoclave 13 is connected to a first channel 24 and a second channel 25. The second channel 25 is connected to the hydrogen measuring box 18 containing electrolyte. The first channel 24 and the second channel 25 are located in the placement cavity formed by the gap between the autoclave 13 and the hydrogen measuring box 18. A sample 31 is placed in the placement cavity.

[0029] like Figure 2As shown, the sample 31 is connected to a loading nut 29. The stress can be changed by attaching strain gauges to the sample surface and rotating the loading nut 29. The loading displacement is measured using a dial gauge 28, and the stress is calculated to generate a stress-loading displacement curve. The sample 31 is connected to a working electrode 15, and the hydrogen measurement box 18 is connected to a reference electrode 16 and an auxiliary electrode 17. The three electrodes are connected to an electrochemical workstation 19 via wires, and the electrochemical workstation 19 is connected to a data acquisition computer 20 via wires for monitoring and collecting hydrogen permeation current.

[0030] The fourth shut-off valve 8 is opened and the fifth shut-off valve 12 is closed. The high-pressure gas cylinder valve is opened, and the gas from the high-pressure gas cylinder is pressurized using the gas pressurization device 7 to generate high-pressure hydrogen for testing, which enters the buffer tank 10. When the temperature of the hydrogen or hydrogen-doped gas in the buffer tank 10 reaches the test temperature, the fourth shut-off valve 8 and the high-pressure gas cylinder valve are closed, and the fifth shut-off valve 12 is opened, instantly applying the gas to the sample 31. The applied gas continuously contacts the surface of the sample 31, and after physical and chemical adsorption, hydrogen atoms are formed on the surface of the sample 31. Under the influence of the concentration gradient, the hydrogen atoms diffuse inside the sample 31. The electrochemical workstation 19 ionizes the hydrogen atoms diffused to the hydrogen measurement box side into hydrogen ions, forming a hydrogen permeation current, and then obtains hydrogen permeation performance data through analysis.

[0031] In this embodiment of the invention, porous metal filters 26 are placed at both the upper and lower ends of the sample 31, with an accuracy of 1µm, but not limited to this. The porous metal filters 26 not only filter out tiny particles in the hydrogen gas, but also maintain good airtightness due to their high filtration accuracy.

[0032] In this embodiment of the invention, an O-ring 27 is placed between the first channel 24 and the sample 31. This seals the gap between the upper part of the sample 31 and other components of the device, preventing hydrogen leakage from the autoclave 13 and ensuring the stability of the hydrogen source supply for the experiment. It also prevents outside air from entering, ensuring the controllability of experimental conditions and making the hydrogen permeation measurement results accurate and reliable. The sample 31 is anchored to the top of the second channel 25 by anchors 30. Anchors 30 are inserted at intervals at positions corresponding to the O-ring 27 on the top of the second channel 25 to anchor the sample 31. This not only restricts the movement of the sample 31 and suppresses the deformation of the sample 31 caused by the instantaneous application of gas, but also reduces the gaps caused by the deformation of the sample 31, effectively preventing lateral gas leakage and ensuring good airtightness of the sealing structure.

[0033] In this embodiment of the invention, the first channel 24 and the second channel 25 are shaped to be wider at the top and narrower at the bottom, which can withstand the deformation of the sample 31 caused by the instantaneous application of high-pressure hydrogen from the top.

[0034] Example 2: This example presents a high-pressure hydrogen permeation testing device under pressure, temperature, and stress, comprising a pressurization system, a temperature control system, and a hydrogen permeation system. This experimental device can simultaneously control three key variables: pressure, temperature, and stress, enabling hydrogen permeation testing under high-pressure conditions. In the pressurization system, a gas cylinder is connected to a gas booster via a valve, allowing for pressure regulation. The temperature control system includes a first heat transfer jacket, a second heat transfer jacket, and a high-precision temperature control device. The high-precision temperature control device is connected to the first and second heat transfer jackets via pipelines, and uses the medium in the circulating heat transfer jackets to control the temperature of hydrogen or hydrogen-doped gas in real time. The hydrogen permeation system includes a high-pressure vessel and a hydrogen measurement box. The hydrogen measurement box contains an electrolyte. The gap between the high-pressure vessel and the hydrogen measurement box forms a placement cavity, in which a sample is placed. The sample is connected to a stress loading device and a working electrode. The hydrogen measurement box is connected to a reference electrode and an auxiliary electrode. The three electrodes are connected to an electrochemical workstation via wires.

[0035] Preferably, porous metal filters are placed at both the upper and lower ends of the sample.

[0036] Preferably, an O-ring is placed between the bottom of the first channel and the sample.

[0037] Preferably, the sample is anchored at the top of the second channel by an anchor.

[0038] Preferably, the pressurization system, temperature control system, and hydrogen permeation system are connected by a certain pipeline. The pressurization system also includes a high-pressure nitrogen cylinder, a high-pressure methane cylinder, a high-pressure hydrogen cylinder, and a buffer tank. The high-pressure nitrogen cylinder, high-pressure methane cylinder, and high-pressure hydrogen cylinder are respectively connected to a gas booster through pipelines; the pipelines are respectively equipped with a first, second, and third shut-off valve; the gas booster is connected to the buffer tank through a pipeline, and the pipeline is equipped with a fourth shut-off valve; the buffer tank is connected to the high-pressure vessel in the hydrogen permeation system through a pipeline, and the pipeline is equipped with a fifth shut-off valve and a pressure gauge; the outer wall of the buffer tank is wrapped with a first heat transfer jacket of the temperature control system, and the first heat transfer jacket is connected to a high-precision temperature control device through a pipeline; the second heat transfer jacket is wrapped around the outside of the high-pressure vessel and is connected to the high-precision temperature control device through a pipeline.

[0039] The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling is used as follows: (1) The sample is processed by wire cutting and precision machining, polished to form a sample with a smooth surface and uniform thickness, and nickel is plated on the hydrogen measurement side. The thickness of the sample, i.e. the penetration distance, is then measured. (2) Place the sample in the placement chamber and test the airtightness of the high-pressure permeation chamber with nitrogen gas; (3) With the fourth shut-off valve open and the fifth shut-off valve closed, open the high-pressure gas cylinder valve. Hydrogen or hydrogen-blended gas is pressurized to the target pressure of the test through the gas booster and transported to the buffer tank through the fourth pipeline. Then, the high-precision temperature control device is used to circulate the temperature control medium and adjust the gas temperature to the preset range. (4) After the gas pressure and temperature reach the preset values, close the fourth shut-off valve and the high-pressure gas cylinder valve, and open the fifth shut-off valve. At this time, high-pressure gas is instantaneously applied into the sample chamber. The high-pressure gas diffuses and permeates through the sample. The hydrogen atoms that permeate to the hydrogen measurement side are oxidized by the anodic potential applied by the electrochemical workstation, forming a hydrogen permeation current. By recording the relationship curve between current and time, a hydrogen permeation current curve is plotted, and the hydrogen permeation performance parameters are obtained through analysis.

Claims

1. A high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling, characterized in that: The testing device includes a hydrogen measuring box (18) connected to the sample (31) at the end of the high-pressure hydrogen supply line. The high-pressure hydrogen supply line is sequentially equipped with a gas source, a gas booster (7), a buffer tank (10), and an autoclave (13). The sample is placed at the hydrogen permeation surface of the autoclave. The buffer tank is wrapped with a first heat transfer jacket (9) for heating. The autoclave is wrapped with a second heat transfer jacket (14) for heating. An external electrochemical workstation (19) is connected to the hydrogen measuring box and the sample through electrodes.

2. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling as described in claim 1, characterized in that: The hydrogen measuring box contains an internal electrolyte, and the external electrochemical workstation (19) is connected to the hydrogen measuring box and the sample via wires, working electrode (15), reference electrode (16), and auxiliary electrode (17) to monitor and collect hydrogen permeation current. When high-pressure hydrogen supply lines deliver hydrogen or hydrogen-doped gas to the sample, causing hydrogen permeation at the sample, the hydrogen atoms that permeate into the hydrogen measuring cell are ionized under the constant potential of the electrochemical workstation to produce hydrogen ions and electrons, thereby forming a hydrogen permeation current.

3. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling as described in claim 1, characterized in that: The gas source includes a high-pressure nitrogen cylinder (1), a high-pressure methane cylinder (2), and a high-pressure hydrogen cylinder (3). The high-pressure nitrogen cylinder (1), the high-pressure methane cylinder (2), and the high-pressure hydrogen cylinder (3) are connected to a gas booster via a first pipe, a second pipe, and a third pipe, respectively, to form a booster system. The gas booster pressurizes the hydrogen or hydrogen-blended gas output from the gas source to form test gas, and then inputs the test gas into a buffer tank via a fourth pipe.

4. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling as described in claim 3, characterized in that: The first, second, and third pipes are respectively equipped with a first shut-off valve (4), a second shut-off valve (5), and a third shut-off valve (6), and the fourth pipe is equipped with a fourth shut-off valve (8).

5. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling as described in claim 3, characterized in that: The first heat transfer jacket and the second heat transfer jacket are connected to a high-precision temperature control device (21) to adjust and maintain the temperature of the test gas in the buffer tank and the autoclave within a preset range.

6. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling as described in claim 5, characterized in that: The high-precision temperature control device is connected to the first and second heat transfer jackets via pipelines to form a temperature control system. The temperature control system regulates and maintains the temperature of the test gas in the buffer tank and the autoclave by circulating and heating the medium in the pipelines and jackets.

7. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling according to claim 3, characterized in that: The surface of the sample is covered with strain gauges that are connected to the loading nut (29).

8. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling according to claim 7, characterized in that: The loading nut is equipped with a dial gauge (28) for measuring the loading displacement. When the stress applied to the specimen by the strain gauge is adjusted by rotating the loading nut, the loading displacement measured by the dial gauge can be used to calculate the stress.

9. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling according to claim 3, characterized in that: The high-pressure vessel and the hydrogen measuring box form a hydrogen permeation system; the high-pressure vessel has an inlet (22) and an outlet (23), and hydrogen or hydrogen-doped gas enters the interior of the high-pressure vessel through the inlet to undergo hydrogen permeation.

10. The high-pressure hydrogen permeation testing device under pressure-temperature-stress coupling according to claim 9, characterized in that: The lower end of the autoclave is connected to a first channel (24) and a second channel (25) arranged in sequence. The second channel is connected to a hydrogen measuring box containing electrolyte. The width of the first channel is greater than that of the second channel. The first channel and the second channel are located between the autoclave and the hydrogen measuring box. The gap between the two channels forms a placement cavity for placing the sample. The sample is connected to the working electrode (15). Porous metal filters (26) are provided at the upper and lower ends of the sample to form a separation structure between the first channel and the second channel.

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