A hydrogen permeation testing device and method coupled with gas-phase hydrogen and corrosion cathodic hydrogen evolution

Abstract

The application belongs to the technical field of hydrogen permeation testing devices, and particularly relates to a hydrogen permeation testing device and method for coupling of gaseous hydrogen and corrosion cathode hydrogen evolution. A sample to be tested is sealed between a double-hydrogen-source hydrogen permeation module and a hydrogen measurement module. The double-hydrogen-source hydrogen permeation module comprises a gaseous hydrogen permeation unit and an electrochemical hydrogen permeation unit arranged in the gaseous hydrogen permeation unit. The two units act on different regions of a first surface of the sample respectively and can be independently or simultaneously operated. The hydrogen measurement module collects hydrogen oxidation current on a second surface of the sample through a three-electrode system. By comparing hydrogen permeation signals of three modes of single gaseous hydrogen permeation, single corrosion cathode hydrogen permeation and double-hydrogen-source coupled hydrogen permeation, the coupling effect of the double-hydrogen-source can be evaluated. The application can be used for hydrogen permeation and hydrogen compatibility evaluation of hydrogen-related pipeline materials, and solves the problem that the prior art can only simulate a single hydrogen source and deviates from the real service conditions of the pipeline.

Description

Technical Field

[0001] This invention belongs to the technical field of hydrogen permeation testing devices, specifically relating to a hydrogen permeation testing device and method that couples gaseous hydrogen with hydrogen evolution at a corrosive cathode. Background Technology

[0002] Utilizing existing natural gas pipeline networks for hydrogen blending and transportation is considered an effective way to achieve large-scale, long-distance, and low-cost hydrogen storage and transportation. However, hydrogen blending during natural gas pipeline transportation can cause hydrogen embrittlement failure in steel pipelines. In particular, with the increase in pipeline steel strength, its unique microstructure and the relative sensitivity of its reinforcement to hydrogen have increased dramatically. This results in high-strength pipe materials being significantly more susceptible to damage during hydrogen blending and transportation than low-strength pipe materials, greatly limiting the application of high-grade steel pipe materials.

[0003] Under actual service conditions, hydrogen-infused pipelines are subjected to two coexisting and coupled hydrogen intrusion sources: one is electrochemical corrosion hydrogen evolution, where the inner wall of the pipeline corrodes under the influence of water and acidic impurities (such as carbon dioxide and hydrogen sulfide), and active hydrogen atoms generated by the cathodic reaction penetrate into the matrix; the other is gas-phase dissociation hydrogen infiltration, where hydrogen molecules in the transport medium dissociate and adsorb on the metal surface, transforming into atomic hydrogen and diffusing inward. These two hydrogen infiltration pathways coexist and superimpose in real-world conditions, greatly accelerating the accumulation of hydrogen atoms inside the pipeline and ultimately leading to severe hydrogen damage. Simultaneously, as the strength of pipeline steel increases, its microstructure becomes dramatically more sensitive to hydrogen, further amplifying the embrittlement risk caused by this dual hydrogen infiltration. Therefore, accurately understanding and distinguishing the infiltration patterns of these two hydrogen sources under real-world coupled conditions is a crucial prerequisite for assessing and preventing hydrogen embrittlement failure in high-strength pipeline steel.

[0004] Currently, hydrogen permeation testing technology mainly follows the Devanathan-Stachurski dual-electrolysis cell principle from 1962, which involves detecting hydrogen permeation by clamping a sample between two cells. Although existing technologies have made improvements, such as an in-situ testing device for multi-factor coupled failure of natural gas hydrogen-blended pipeline steel, whose hydrogen permeation chamber also serves as a corrosion chamber to simulate electrochemical corrosion or high-pressure gas phase environments, this device can only provide a single hydrogen source and cannot simultaneously apply two hydrogen sources in a single test and distinguish the permeation contribution of the two hydrogen sources. Another example is a high-pressure gas phase hydrogen permeation kinetic testing device simulating the coupling of hydrogen-containing pipe materials and hydrogen-blended environments, which only tests the gas phase hydrogen environment and does not consider the superimposed effect of cathodic hydrogen evolution caused by electrochemical corrosion of the pipeline inner wall on hydrogen permeation. Yet another example is a device and method for studying the hydrogen permeation behavior of metals, whose hydrogen permeation electrolysis cell can only provide a single hydrogen source for electrochemical hydrogen charging. It is evident that existing testing devices can only provide a single liquid-phase electrochemical hydrogen filling environment or a single gas-phase hydrogen filling environment, and cannot simultaneously apply two hydrogen sources in a single test. This results in a severe disconnect between the test environment and the actual "dual-path coupling" operating conditions faced by hydrogen-doped pipelines. This single-hydrogen-source testing mode makes it impossible for researchers to quantify and distinguish the contribution rates of the two hydrogen permeation paths, and also makes it difficult to assess the synergistic effect of their superposition. Consequently, the test results cannot accurately reflect the hydrogen embrittlement risk of the pipe material in actual service. Summary of the Invention

[0005] The purpose of this invention is to provide a hydrogen permeation testing device and method that couples gaseous hydrogen with hydrogen evolution at a corrosion cathode, thereby overcoming the shortcomings of the prior art. This invention can simultaneously simulate hydrogen permeation testing devices and methods that utilize two hydrogen sources: electrochemical corrosion at a corrosion cathode and hydrogen evolution at a gaseous cathode. It enables independent control of the two hydrogen sources and online measurement of the hydrogen permeation current, providing a reliable testing method for evaluating the hydrogen compatibility and service safety of hydrogen-blended natural gas pipelines.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: On the one hand, the present invention provides a hydrogen permeation testing device coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, including a dual hydrogen source hydrogen permeation module, a hydrogen measurement module, and a sample clamping module located between the two. The sample clamping module seals and fixes the sample to be tested between the dual hydrogen source hydrogen permeation module and the hydrogen measurement module, so that the first surface of the sample to be tested is exposed to the dual hydrogen source hydrogen permeation module and the second surface is exposed to the hydrogen measurement module. The dual-hydrogen source hydrogen permeation module includes a gas phase hydrogen permeation unit and an electrochemical hydrogen permeation unit. The gas phase hydrogen permeation unit is used to provide a gas phase hydrogen molecule dissociation hydrogen permeation environment to the first surface of the test sample, and the electrochemical hydrogen permeation unit is used to provide an electrochemical corrosion cathode hydrogen evolution environment to the first surface of the test sample. The gas-phase hydrogen permeation unit and the electrochemical hydrogen permeation unit operate independently or simultaneously.

[0007] This testing device enables the simultaneous simulation of two actual hydrogen sources in service in hydrogen-blended natural gas pipelines within a single testing unit: coupled hydrogen permeation processes involving electrochemical corrosion cathodic hydrogen evolution and gas-phase hydrogen dissociation and adsorption. By independently controlling two units, it can perform individual tests of the two hydrogen sources or simultaneous operation tests of both hydrogen sources, thus solving the problem that existing technologies can only simulate a single hydrogen source and deviate from the actual service conditions of pipelines.

[0008] On the other hand, the present invention provides a hydrogen permeation testing method coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, employing a hydrogen permeation testing device coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, comprising the following steps: (1) The sample to be tested is sealed and installed in the clamping module, with the first surface facing the dual hydrogen source hydrogen permeation module and the second surface facing the hydrogen measurement module; (2) Inject alkaline electrolyte into the hydrogen measurement module and construct a three-electrode system, and apply a constant anodic potential to the second surface of the sample to be tested for polarization; (3) Adjust the operation mode of the dual hydrogen source hydrogen permeation module and record the hydrogen permeation current-time curve through the data acquisition module; (4) Based on the obtained hydrogen permeation current-time curve, calculate the steady-state hydrogen permeation current density and perform coupling effect analysis; (5) Adjust the hydrogen permeation parameters, repeat steps (3) and (4), and establish hydrogen permeation behavior spectra of the test sample under different hydrogen permeation parameters.

[0009] This testing method employs a dual-hydrogen-source device, enabling precise simulation from single-environment testing to complex coupled operating conditions. By utilizing steady-state current density calculation and multi-parameter spectrum construction, it can not only quantitatively analyze the competition and synergistic mechanism between gaseous hydrogen and corrosion-induced hydrogen evolution, but also systematically reveal the hydrogen capture and diffusion laws of materials under different pressures, potentials, and media, providing experimental evidence with both high fidelity and high throughput for hydrogen embrittlement sensitivity assessment.

[0010] The beneficial effects of this invention are: (1) This invention is the first to realize the simultaneous simulation of two actual hydrogen sources in service in a hydrogen-blended natural gas pipeline in a single test device: electrochemical corrosion cathode hydrogen evolution and gas phase hydrogen dissociation adsorption coupled hydrogen permeation process. By independently controlling the two units, it is possible to conduct separate tests of the two hydrogen sources or to conduct tests of dual hydrogen source operation at the same time, which solves the problem that the existing technology can only simulate a single hydrogen source and has deviations from the actual service conditions of the pipeline.

[0011] (2) By nesting an electrochemical hydrogen permeation chamber inside the gas phase hydrogen permeation chamber, the electrochemical hydrogen permeation chamber only contacts a local area of ​​the first surface of the sample, while the gas phase hydrogen permeation chamber covers the entire first surface, accurately simulating the working condition of local corrosion area and large area gas phase hydrogen environment coexisting in actual pipeline.

[0012] (3) By setting up three test modes, namely Mode A, Mode B and Mode C, and comparing the results of Mode C with those of Mode A and Mode B, it is possible to quantitatively evaluate whether there is a synergistic enhancement effect or a mutual inhibition effect between the two hydrogen sources, namely electrochemical corrosion hydrogen evolution and hydrogen permeation and gas phase hydrogen dissociation and hydrogen permeation. This provides an effective means for a deeper understanding of the hydrogen permeation mechanism under actual working conditions of hydrogen-blended natural gas pipelines.

[0013] (4) The test device has a compact structure and flexible operation. It can independently control and adjust parameters such as gas phase hydrogen partial pressure, gas pressure, temperature, corrosive medium composition and pH value, and cathode potential. It is suitable for hydrogen permeation testing under different hydrogen doping ratios, different delivery pressures, and different corrosive environments, and has a wide range of working conditions adaptability.

[0014] (5) The test method is simple and reliable, and the data processing scheme is complete. The contribution ratio of the two hydrogen sources to the total hydrogen permeation flux can be calculated by area normalization, which provides a quantitative basis for the selection of materials, corrosion protection design and operation safety assessment of hydrogen-blended natural gas pipelines. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is a schematic diagram of the overall structure of the hydrogen permeation testing device for a hydrogen-blended natural gas pipeline in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the dual-hydrogen-source hydrogen permeation module in Embodiment 1 of the present invention; The markings in the attached diagram are as follows: 101-Gas phase hydrogen permeation chamber; 102-Electrochemical hydrogen permeation chamber; 103-First auxiliary electrode; 104-First reference electrode; 105-Sealing ring; 201-Hydrogen electrolysis cell; 202-Alkaline electrolyte solution; 203-Second auxiliary electrode; 204-Second reference electrode; 3-Test sample; 4-Sample clamping module; 501-Hydrogen gas source; 502-Methane gas source; 503-Impurity gas source; 504-Mass flow controller; 505-Gas mixing tank; 506-Humidity regulator; 601-Corrosive medium storage tank; 602-Peristaltic pump; 7-Electrochemical workstation; 8-Potentialometer; 9-Temperature and pressure control module. Detailed Implementation

[0017] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Specific conditions not specified in the embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Components whose manufacturers are not specified are all commercially available conventional products.

[0018] Existing hydrogen permeation testing equipment cannot simultaneously simulate the coupling effect of the two hydrogen sources mentioned above in the same device, resulting in a large deviation between the test results and the actual service conditions of hydrogen-blended natural gas pipelines. This makes it difficult to accurately evaluate the hydrogen permeation behavior and hydrogen embrittlement sensitivity of pipeline materials under actual dual hydrogen source conditions.

[0019] On the one hand, the present invention provides a hydrogen permeation testing device coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, including a dual hydrogen source hydrogen permeation module, a hydrogen measurement module, and a sample clamping module located between the two. The sample clamping module seals and fixes the sample to be tested between the dual hydrogen source hydrogen permeation module and the hydrogen measurement module, so that the first surface of the sample to be tested is exposed to the dual hydrogen source hydrogen permeation module and the second surface is exposed to the hydrogen measurement module. The dual-hydrogen source hydrogen permeation module includes a gas-phase hydrogen permeation unit and an electrochemical hydrogen permeation unit. The gas-phase hydrogen permeation unit is used to provide a gas-phase hydrogen molecule dissociation and hydrogen permeation environment to the first surface of the test sample, and the electrochemical hydrogen permeation unit is used to provide an electrochemical corrosion cathode hydrogen evolution environment to the first surface of the test sample.

[0020] This device is suitable for hydrogen-blended natural gas pipelines and can simultaneously simulate hydrogen permeation tests from two sources: cathodic hydrogen evolution due to corrosion of the pipeline inner wall and gas-phase hydrogen dissociation and adsorption. It can accurately evaluate the hydrogen permeation behavior and hydrogen embrittlement sensitivity of pipeline materials under actual dual hydrogen source conditions.

[0021] Furthermore, the test sample is a metal sample, and the second surface is plated with a nickel layer or a palladium layer. The nickel or palladium layer pre-plated on the second surface can enhance the hydrogen atom oxidation signal.

[0022] Furthermore, the gas phase hydrogen permeation unit includes a gas supply unit, a gas component control unit, and a gas phase hydrogen permeation chamber connected in sequence; The gas supply unit is connected to a hydrogen-containing mixed gas source, which includes hydrogen, methane, carbon dioxide, hydrogen sulfide, oxygen, nitrogen, etc. The gas phase hydrogen permeation chamber is equipped with an inlet pipe and an outlet pipe. The gas component control unit is connected to the inlet and outlet pipes of the gas phase hydrogen permeation cavity to form a closed-loop or semi-closed-loop gas circulation loop. The gas-phase hydrogen permeation chamber is connected to the first surface of the sample to be tested.

[0023] Specifically, the gas supply unit is used to provide a hydrogen-containing mixed gas (simulating hydrogen-blended natural gas), including a hydrogen gas source, a methane gas source, and impurity gas sources (such as carbon dioxide, hydrogen sulfide, oxygen, nitrogen, etc.) as needed. Each gas source is connected to the gas mixing tank through a mass flow controller.

[0024] The gas composition control unit includes a gas mixing tank, a humidity regulator (used to simulate the condensate film environment on the inner wall of the pipe), and a gas preheater.

[0025] The gas-phase hydrogen permeation chamber faces the first surface of the sample to be tested, allowing the hydrogen-containing gas mixture to directly contact the first surface. Hydrogen molecules in the gas phase undergo dissociation and adsorption on the sample surface, and the resulting hydrogen atoms permeate into the sample. The gas-phase hydrogen permeation chamber is equipped with pressure and temperature sensors. An inlet solenoid valve is installed on the inlet pipe, and an exhaust solenoid valve and a back pressure regulating valve are installed on the outlet pipe to precisely control the gas pressure within the chamber.

[0026] Furthermore, the electrochemical hydrogen permeation unit includes a corrosive medium supply unit and an electrochemical hydrogen permeation chamber. The electrochemical hydrogen permeation chamber is provided with an inlet and an outlet. The corrosive medium supply unit is connected to the inlet and outlet of the electrochemical hydrogen permeation chamber to form a circulating or static mode. The corrosive medium supply unit is connected to a corrosive medium source, which includes an acidic solution containing carbon dioxide or hydrogen sulfide or other corrosive solutions. Specifically, the corrosive medium supply unit includes a corrosive medium storage tank and a peristaltic pump, which are used to supply an electrolyte solution containing corrosive components (simulating the corrosive environment in the condensate film or accumulated liquid on the inner wall of the pipeline, such as an acidic solution containing carbon dioxide or hydrogen sulfide, etc.) to the electrochemical hydrogen permeation chamber, and control the pH value of the solution through a pH adjustment device.

[0027] The opening of the electrochemical hydrogen permeation chamber is sealed to the first surface by a sealing ring, so that the electrolyte solution comes into contact with a local area of ​​the first surface of the sample. An electrochemical corrosion reaction occurs in this area, and hydrogen atoms evolved from the cathode directly permeate into the interior of the sample.

[0028] The electrochemical hydrogen permeation chamber is equipped with auxiliary electrodes (such as platinum electrodes or graphite electrodes) and reference electrodes (such as saturated calomel electrodes or Ag / AgCl electrodes), which are connected to the electrochemical workstation. The rate of the cathodic hydrogen evolution reaction is controlled by applying a cathode potential or controlling the corrosion potential. The electrochemical hydrogen permeation chamber has an inlet and an outlet, which are connected to the corrosion medium supply unit, respectively, enabling the operation of the corrosion medium in either circulating or static mode.

[0029] The electrochemical hydrogen permeation chamber is disposed within the gas phase hydrogen permeation chamber of the gas phase hydrogen permeation unit, and the electrochemical hydrogen permeation chamber is connected to a local area of ​​the first surface of the sample to be tested.

[0030] Specifically, the volume of the gas-phase hydrogen permeation chamber is generally larger than that of the electrochemical hydrogen permeation chamber, ensuring that the gas-phase hydrogen permeation chamber has a sufficiently large volume to guarantee the stability of the gas environment. Simultaneously, the electrochemical hydrogen permeation chamber only contacts a localized area of ​​the first surface of the sample, simulating a localized corrosion environment of the pipe wall. Preferably, the contact area between the electrochemical hydrogen permeation chamber and the first surface of the sample, and the total contact area between the gas-phase hydrogen permeation chamber and the first surface of the sample, form a geometrical ratio, facilitating subsequent calculations of the permeation flux contributions from the two hydrogen sources through area normalization.

[0031] Furthermore, the gas-phase hydrogen permeation unit and the electrochemical hydrogen permeation unit operate independently or simultaneously. The hydrogen measurement module includes a hydrogen measurement electrolytic cell and a three-electrode electrochemical measurement unit connected in sequence. The hydrogen electrolytic cell is equipped with an alkaline electrolyte solution. The hydrogen electrolysis cell is sealed to the second surface of the sample to be tested; The three-electrode electrochemical measurement unit uses the second surface of the sample to be tested as the working electrode.

[0032] Specifically, the hydrogen electrolysis cell is sealed to the second surface of the sample and contains an alkaline electrolyte solution (such as 0.1~1 mol / L NaOH solution). This allows hydrogen atoms escaping from the second surface of the sample to be oxidized to H+ under an applied constant anodic potential. + This generates hydrogen permeation current.

[0033] A three-electrode electrochemical measurement system includes a working electrode (the second surface of the sample), an auxiliary electrode (such as a platinum wire), and a reference electrode (such as a Hg / HgO electrode), which is connected to an electrochemical workstation or a potentiostat.

[0034] Furthermore, it also includes a temperature and pressure control module, a data acquisition module, and an external load module; The temperature and pressure control module includes a heating device and a temperature and pressure control device. The temperature and pressure control module is connected to the dual-hydrogen source hydrogen permeation module and the hydrogen measurement module, respectively. The temperature and pressure control module is used to maintain the dual-hydrogen source hydrogen permeation module and the hydrogen measurement module at a set temperature (-50℃~200℃) and to control the gas pressure inside the gas phase hydrogen permeation chamber (0.1MPa~20MPa).

[0035] The data acquisition module includes an electrochemical workstation, a potentiostat, a pressure sensor, a temperature sensor, and a mass flow controller; the data acquisition module is connected to the temperature and pressure control module, the dual hydrogen source hydrogen permeation module, and the hydrogen measurement module, respectively; the data acquisition module is used to record the hydrogen permeation current-time curve, gas pressure, temperature, and flow rate data of each gas component in real time.

[0036] The external load module is connected to the test sample and is used to apply tensile or bending stress to the test sample to simulate the stress conditions of the pipe under service conditions. The external load module can be a constant displacement loading tension ring or a mechanical loading device, applied to both ends of the test sample.

[0037] On the other hand, the present invention provides a hydrogen permeation testing method coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, employing a hydrogen permeation testing device coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, comprising the following steps: (1) The sample to be tested is sealed and installed in the clamping module, with the first surface facing the dual hydrogen source hydrogen permeation module and the second surface facing the hydrogen measurement module; (2) Inject alkaline electrolyte into the hydrogen measurement module and construct a three-electrode system, and apply a constant anodic potential to the second surface of the sample to be tested for polarization; (3) Adjust the operation mode of the dual hydrogen source hydrogen permeation module and record the hydrogen permeation current-time curve through the data acquisition module; (4) Based on the obtained hydrogen permeation current-time curve, calculate the steady-state hydrogen permeation current density and perform coupling effect analysis; (5) Adjust the hydrogen permeation parameters, repeat steps (3) and (4), and establish hydrogen permeation behavior spectra of the test sample under different hydrogen permeation parameters.

[0038] Furthermore, the dual-hydrogen-source hydrogen permeation module operates in any of the following modes: Single electrochemical hydrogen permeation mode: Corrosive medium is injected into the electrochemical hydrogen permeation chamber and a cathode potential or natural corrosion potential is applied, while inert gas is introduced into the gas phase hydrogen permeation chamber to maintain pressure balance. Single gas phase hydrogen permeation mode: The gas phase hydrogen permeation chamber is filled with a hydrogen-containing mixed gas, while the electrochemical hydrogen permeation chamber is left empty; Dual-source coupled hydrogen permeation mode: A hydrogen-containing mixed gas is introduced into the gas phase hydrogen permeation chamber, while a corrosive medium is introduced into the electrochemical hydrogen permeation chamber and a potential is applied.

[0039] Furthermore, the coupling effect analysis is as follows: obtaining the steady-state hydrogen permeation current density of single electrochemical corrosion hydrogen permeation. J corr Steady-state hydrogen permeation current density of single-phase gaseous hydrogen dissociation and hydrogen permeation J gas Total steady-state hydrogen permeation current density under dual hydrogen source coupling conditions J total ; Compare J total and J corr + J gas Relationship: If Jtotal > J corr + J gas When this occurs, it indicates the presence of a positive coupling enhancement effect; if J total < J corr + J gas When the value is 0, it indicates the presence of an inhibitory effect.

[0040] Furthermore, the second surface of the test sample is plated with a nickel plating layer or a palladium plating layer, and the plating layer thickness is 0.1~2 μm; A constant anode potential is applied, which is +150 mV to +300 mV relative to the reference electrode; The hydrogen permeation parameters include temperature, gas composition, gas pressure, pH value of the corrosive medium, and cathode potential.

[0041] The following is a further explanation with reference to specific embodiments: Example 1 A hydrogen permeation testing device coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode, such as... Figure 1 As shown, it includes a dual-hydrogen-source hydrogen permeation module, a hydrogen measurement module, a test sample 3, a sample clamping module 4, a gas-phase hydrogen permeation unit, an electrochemical hydrogen permeation unit, an electrochemical workstation 7, a potentiostat 8, a temperature and pressure control module 9, a data acquisition module, an external load module, and related pipelines and valves.

[0042] Specifically, a test sample 3 is provided between the dual-hydrogen source hydrogen permeation module and the hydrogen measurement module, and both sides of the test sample 3 are fixed to the hydrogen measurement module by the sample clamping module 4, sealing the two sides of the test sample 3 to the dual-hydrogen source hydrogen permeation module and the hydrogen measurement module. For example, the test sample 3 is a sheet-like metal sample, with its first surface facing the dual-hydrogen source hydrogen permeation module and its second surface facing the hydrogen measurement module; the second surface of the sheet-like metal sample is pre-plated with a nickel or palladium layer to enhance the hydrogen atom oxidation signal.

[0043] The gas-phase hydrogen permeation unit and the electrochemical hydrogen permeation unit can operate independently or simultaneously. The gas-phase hydrogen permeation unit includes a high-pressure gas supply unit, a gas component control unit, and a gas-phase hydrogen permeation chamber 101. The high-pressure gas supply unit provides a hydrogen-containing mixed gas (simulating hydrogen-blended natural gas), including a hydrogen source 501, a methane source 502, and an impurity gas source 503 configured as needed. The impurity gas sources include carbon dioxide, hydrogen sulfide, oxygen, nitrogen, etc. Each gas source is connected to a gas mixing tank 505 via a mass flow controller 504. The gas component control unit includes a gas mixing tank 505, a humidity regulator 506, and a gas preheater; the gas component control unit simulates the condensate film environment on the inner wall of the pipeline.

[0044] The gas-phase hydrogen permeation chamber is connected to the gas component control unit via inlet and outlet pipes, forming a closed-loop or semi-closed-loop gas circulation circuit. The gas-phase hydrogen permeation chamber faces the first surface of the test sample 3, allowing the hydrogen-containing gas mixture to directly contact the first surface. Hydrogen molecules in the gas phase undergo dissociation and adsorption on the surface of the first surface of the test sample 3, and the resulting hydrogen atoms permeate into the sample. The gas-phase hydrogen permeation chamber is equipped with pressure and temperature sensors. An inlet solenoid valve is installed on the inlet pipe, and an exhaust solenoid valve and a back pressure regulating valve are installed on the outlet pipe for precise control of the gas pressure within the chamber.

[0045] The electrochemical hydrogen permeation unit includes a corrosion medium supply unit and an electrochemical hydrogen permeation chamber 102. The corrosion medium supply unit includes a corrosion medium storage tank 601 and a peristaltic pump 602, used to supply an electrolyte solution containing corrosive components (simulating the corrosive environment of condensate film or accumulated liquid on the inner wall of a pipe, such as an acidic solution containing carbon dioxide or hydrogen sulfide) to the electrochemical hydrogen permeation chamber, and controlling the pH value of the solution through a pH adjustment device. The electrochemical hydrogen permeation chamber 102 is located inside the gas-phase hydrogen permeation chamber 101, opposite a local area of ​​the first surface of the test sample 3. The opening end of the electrochemical hydrogen permeation chamber is sealed to the first surface by a sealing ring 105, allowing the electrolyte solution to contact the local area of ​​the first surface of the test sample 3, where an electrochemical corrosion reaction occurs, and hydrogen atoms evolved from the cathode directly permeate into the sample.

[0046] The electrochemical hydrogen permeation chamber is equipped with a first auxiliary electrode 103 and a first reference electrode 104, both of which are connected to the electrochemical workstation 7. The rate of the cathodic hydrogen evolution reaction is controlled by applying a cathode potential or controlling the corrosion potential. For example, the first auxiliary electrode 103 can be a platinum electrode or a graphite electrode, and the first reference electrode 104 can be a saturated calomel electrode or an Ag / AgCl electrode. The rate of the cathodic hydrogen evolution reaction is controlled by applying a cathode potential or controlling the corrosion potential. The electrochemical hydrogen permeation chamber has an inlet and an outlet, which are respectively connected to the corrosion medium supply unit, enabling either cyclic or static operation of the corrosion medium.

[0047] like Figure 2As shown, the volume of the gas-phase hydrogen permeation chamber 101 is generally larger than that of the electrochemical hydrogen permeation chamber 102, ensuring that the gas-phase hydrogen permeation chamber 101 has a sufficiently large volume to guarantee the stability of the gas environment. Meanwhile, the electrochemical hydrogen permeation chamber 102 only contacts a localized area of ​​the first surface of the sample, simulating a localized corrosion environment of the pipe wall. The contact area between the electrochemical hydrogen permeation chamber 102 and the first surface of the sample, and the total contact area between the gas-phase hydrogen permeation chamber 101 and the first surface of the sample, form a geometrical ratio, facilitating subsequent calculation of the permeation flux contribution of the two hydrogen sources through area normalization. The hydrogen measurement module includes a hydrogen measurement electrolytic cell 201 and a three-electrode electrochemical measurement system. The hydrogen measurement electrolytic cell is sealed to the second surface of the test sample 3 and contains an alkaline electrolyte solution 202. For example, the alkaline electrolyte solution 202 can be a 0.1~1 mol / L NaOH solution, which oxidizes hydrogen atoms escaping from the second surface of the test sample 3 to H under an applied constant anodic potential. + This generates a hydrogen permeation current. The three-electrode electrochemical measurement system includes a working electrode (the second surface of the sample), a second auxiliary electrode 203 (such as a platinum wire), and a second reference electrode 204 (such as a Hg / HgO electrode), which are connected to an electrochemical workstation 7 or a potentiostat 8.

[0048] The temperature and pressure control module includes a temperature control system and a pressure control system. The temperature control system includes a heating mantle or constant temperature chamber and a temperature controller, used to maintain the dual-hydrogen source hydrogen permeation module and the hydrogen measurement module at the set temperature (-50℃~200℃). The pressure control system is connected to the gas phase hydrogen permeation chamber and is used to control the gas pressure inside the gas phase hydrogen permeation chamber (0.1 MPa~20 MPa).

[0049] The data acquisition module is electrically connected to the pressure sensor and temperature sensor in the electrochemical workstation 7 or potentiostat 8, the temperature and pressure control module 9, and the mass flow controller in the gas phase hydrogen permeation unit, and is used to record the hydrogen permeation current-time curve, gas pressure, temperature, and flow data of each gas component in real time.

[0050] The external load module is used to apply tensile or bending stress to the test specimen 3 to simulate the stress conditions of the pipe under service conditions. The external load module can be a constant displacement loading tension ring or a mechanical loading device, which is applied to both ends of the specimen.

[0051] Example 2 A hydrogen permeation testing method for hydrogen-blended natural gas pipelines using dual hydrogen sources, based on the aforementioned hydrogen permeation testing device coupling gaseous hydrogen with hydrogen evolution at a corrosion cathode, includes the following steps: Step 1: Sample Preparation: Cut sheet-like samples from the pipe material to be tested, and perform mechanical grinding and polishing sequentially. Electroless nickel plating or electrochemical nickel plating (or palladium plating) is applied to the second surface of the sample, with the plating thickness controlled between 0.1 and 2 μm to ensure high sensitivity of the hydrogen atom oxidation reaction on the second surface. The first surface of the sample remains in its original ground state. The sample is then installed in the sample clamping module, ensuring that both sides of the sample are sealed to the dual-hydrogen source hydrogen permeation module and the hydrogen measurement module, respectively.

[0052] Step 2: Assembly and Sealing Inspection of the Apparatus: Assemble the gas-phase hydrogen permeation chamber and the electrochemical hydrogen permeation chamber in sequence, check each sealing surface, and perform a gas tightness test. Inject an alkaline electrolyte solution into the hydrogen electrolysis cell, install the three-electrode system, and connect it to the electrochemical workstation. Apply a constant anodic potential (+150 mV to +300 mV relative to the reference electrode, such as +200 mV vs. Hg / HgO to oxidize hydrogen atoms) to the second surface of the sample, and continue polarization until the background current density drops to a stable level (usually below 0.1 μA / cm²), then begin the hydrogen permeation test.

[0053] Step 3: Dual Hydrogen Source Test Mode Operation: The dual hydrogen source hydrogen permeation module can be operated in any of the following modes: Mode A (Electrochemical Hydrogen Permeation Standalone Mode): Only the electrochemical hydrogen permeation unit is activated. Corrosive media is injected into the electrochemical hydrogen permeation chamber through the corrosion medium supply unit, applying a set cathode potential or controlling the natural corrosion potential. Simultaneously, the gas-phase hydrogen permeation unit is not filled with hydrogen-containing gas (an inert gas such as N2 can be used to maintain pressure balance). The data acquisition module records the hydrogen permeation current-time curve in this mode.

[0054] Mode B (Gas-phase hydrogen permeation standalone mode): Only the gas-phase hydrogen permeation unit is activated. A hydrogen-containing mixed gas (simulating hydrogen-blended natural gas, hydrogen volume percentage 1%~100%) with a set composition and pressure is introduced into the gas-phase hydrogen permeation chamber. Simultaneously, the electrochemical hydrogen permeation unit is not operating, and the electrochemical hydrogen permeation chamber is in an unused state. The data acquisition module records the hydrogen permeation current-time curve in this mode.

[0055] Mode C (Dual Hydrogen Source Simultaneous Operation Mode): The gas-phase hydrogen permeation unit and the electrochemical hydrogen permeation unit are simultaneously activated, each operating according to set parameters. The proportions of each component and the total flow rate in the hydrogen-containing gas mixture are set via a mass flow controller. The gas is heated to the set temperature and the humidity is adjusted via a gas preheater and humidity regulator. A corrosive medium is supplied to the electrochemical hydrogen permeation chamber via a corrosion medium supply unit. The corrosion potential is controlled by the electrochemical workstation, or a cathode potential is applied to adjust the cathode hydrogen evolution rate. The data acquisition module records the hydrogen permeation current-time curve in this mode.

[0056] Step 4: Calculation and Analysis of Hydrogen Permeation Parameters. The data processing steps are as follows: The steady-state hydrogen permeation current density for single electrochemical corrosion hydrogen permeation was obtained based on the results of Mode A. J corr ; The steady-state hydrogen permeation current density for single-phase hydrogen dissociation and permeation was obtained based on the results of Mode B. J gas ; The total steady-state hydrogen permeation current density under dual hydrogen source coupling conditions was obtained based on the results of Mode C. J total ; Compare J total and J corr + J gas To determine the relationship between the two hydrogen sources and whether there is a synergistic or inhibitory effect: when J total > J corr + J gas When, it indicates the existence of a positive coupling enhancement effect; when J total < J corr + J gas When this occurs, it indicates the presence of an inhibitory effect; The effective hydrogen diffusion coefficient, subsurface hydrogen concentration, and hydrogen permeation flux were calculated using Fick's diffusion law based on the hydrogen permeation current density and the known sample thickness. By conducting tests under different hydrogen partial pressure conditions (such as 1%~100% hydrogen gas integral number) using Mode B, the relationship between gas phase hydrogen permeation current density and hydrogen partial pressure was established to determine whether the permeation process is controlled by surface dissociation or bulk diffusion.

[0057] Step 5: Repeat the test: Change the hydrogen permeation parameters (temperature, gas composition, gas pressure, pH value of the corrosive medium, and cathode potential, etc.) and repeat the above test to obtain the hydrogen permeation behavior of hydrogen-blended natural gas pipeline materials under dual hydrogen source conditions under different operating conditions.

[0058] Example 3 The following describes the specific implementation process using X80 pipeline steel for a hydrogen-blended natural gas pipeline as an example: Sample preparation: A sheet sample with dimensions of 30 mm × 30 mm × 1 mm was cut from the X80 pipeline steel pipe. The second surface was polished with sandpaper ranging from 400# to 2000#, and then mechanically polished with 1 μm diamond polishing paste. Immediately after polishing, electrochemical nickel plating was performed in a Watt's nickel plating solution. The solution composition was 250 g / L NiSO4·6H2O + 45 g / L NiCl2·6H2O + 35 g / L H3BO3, the current density was 2 mA / cm², and the plating time was 3 minutes, resulting in a nickel plating layer approximately 0.5 μm thick. The first surface of the sample was polished with 600# sandpaper until uniform to simulate the actual roughness of the pipeline inner wall. The sample was ultrasonically cleaned with anhydrous ethanol, dried, and stored for later use.

[0059] Test parameter settings: The gas composition of the gas phase hydrogen permeation unit was set to a natural gas-blended environment with a hydrogen component of 10% (simulating a typical hydrogen blending ratio), a methane volume fraction of 89%, and a carbon dioxide volume fraction of 1% (simulating acidic impurities). The total pressure was 4 MPa, and the temperature was set to 55℃. The gas flow rate was set to 200 mL / min (under standard conditions), and the humidity was controlled at 80% relative humidity using a humidity regulator (simulating the condensation environment on the inner wall of the pipeline). The corrosion medium for the electrochemical hydrogen permeation unit was a 3.5 wt.% NaCl solution containing saturated carbon dioxide, with a pH value of approximately 4.0 (adjusted by introducing carbon dioxide), simulating the acidic condensate corrosion environment on the inner wall of the pipeline. The NaOH solution concentration for the hydrogen measurement module was 0.1 mol / L, and a constant anolyte potential of +200 mV vs. Hg / HgO was applied.

[0060] The specific testing steps are as follows: (1) Install the prepared sample into the sample clamping module 4 and ensure a seal.

[0061] (2) Inject 0.1 mol / L NaOH solution into the hydrogen electrolysis cell 201 to completely immerse the second surface of the sample. Install the auxiliary electrode and the reference electrode, connect the potentiostat 8, and apply an anodic potential of +200 mV (vs. Hg / HgO) to the second surface of the sample.

[0062] (3) Continue polarization until the background current density drops below 0.05 μA / cm², indicating that the oxidizable impurities on the second surface of the sample have been basically removed.

[0063] (4) Mode A Test (Electrochemical Hydrogen Permeation Only): A 3.5 wt.% NaCl solution containing saturated carbon dioxide was introduced into the electrochemical hydrogen permeation chamber 102, and high-purity nitrogen gas (to replace the hydrogen-containing gas and eliminate the influence of gaseous hydrogen) was introduced into the gas phase hydrogen permeation chamber 101 to a equilibrium pressure of 4 MPa. The hydrogen permeation current density-time curve under electrochemical corrosion hydrogen permeation conditions was recorded, and the test was continued until the current density reached a stable value. J corr .

[0064] (5) After the background current level is restored, perform Mode B testing (gas-phase hydrogen permeation only): Empty the corrosive medium from the electrochemical hydrogen permeation chamber 102, and introduce a hydrogen-containing mixed gas (10% hydrogen + 89% methane + 1% carbon dioxide) into the gas-phase hydrogen permeation chamber 101. The total pressure is 4 MPa, and the temperature is 55℃. Record the hydrogen permeation current density-time curve under gas-phase hydrogen permeation conditions, and continue testing until the current density reaches a stable value. J gas .

[0065] (6) After the current level returns to the background level, perform the Mode C test (dual hydrogen sources operating simultaneously): simultaneously turn on the gas phase hydrogen permeation unit 5 and the electrochemical hydrogen permeation unit 6, with parameters consistent with those of Mode A and Mode B, respectively. Record the hydrogen permeation current density-time curve under dual hydrogen source coupling conditions, and continue testing until the current density reaches a stable value. J total .

[0066] (7) Analyze the steady-state hydrogen permeation current density under the three modes based on the test results, calculate the effective hydrogen diffusion coefficient and the subsurface hydrogen concentration of the sample, and compare them. J total and J corr + J gas The magnitude of the hydrogen source coupling effect was determined by analyzing its relationship with the hydrogen source to assess its type (synergistic enhancement or inhibition) and extent. Further changes in parameters such as hydrogen partial pressure, temperature, and total gas pressure were made, and the above tests were repeated to systematically evaluate the hydrogen permeation behavior of X80 pipeline steel under different hydrogen doping conditions.

[0067] The testing apparatus and method provided by this invention can accurately reproduce the hydrogen permeation process of hydrogen-blended natural gas pipelines under actual service conditions in the laboratory. The test results can provide important data support for material selection, hydrogen blending ratio optimization, corrosion protection measures formulation, and pipeline service safety assessment for hydrogen-blended natural gas pipelines. Furthermore, by adjusting the gas composition, corrosive medium composition, and temperature and pressure parameters, this apparatus is also applicable to hydrogen permeation performance testing of pipelines in hydrogen-related environments such as pure hydrogen pipelines and acidic oil and gas pipelines containing hydrogen sulfide / carbon dioxide, demonstrating broad engineering application prospects.

[0068] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydrogen permeation testing device coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode, characterized in that, It includes a dual-hydrogen-source hydrogen permeation module, a hydrogen measurement module, and a sample clamping module located between the two. The sample clamping module seals and fixes the sample to be tested between the dual hydrogen source hydrogen permeation module and the hydrogen measurement module, so that the first surface of the sample to be tested is exposed to the dual hydrogen source hydrogen permeation module and the second surface is exposed to the hydrogen measurement module. The dual-hydrogen source hydrogen permeation module includes a gas phase hydrogen permeation unit and an electrochemical hydrogen permeation unit. The gas phase hydrogen permeation unit is used to provide a gas phase hydrogen molecule dissociation hydrogen permeation environment to the first surface of the test sample, and the electrochemical hydrogen permeation unit is used to provide an electrochemical corrosion cathode hydrogen evolution environment to the first surface of the test sample. The gas-phase hydrogen permeation unit and the electrochemical hydrogen permeation unit operate independently or simultaneously.

2. The hydrogen permeation testing apparatus for coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode as described in claim 1, characterized in that, The test sample is a metal sample, and the second surface of the test sample is plated with a nickel layer or a palladium layer.

3. The hydrogen permeation testing apparatus for coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode as described in claim 1, characterized in that, The gas phase hydrogen permeation unit includes a gas supply unit, a gas component control unit, and a gas phase hydrogen permeation chamber connected in sequence. The gas supply unit is connected to a hydrogen-containing mixed gas source, which includes one or more of hydrogen, methane, carbon dioxide, hydrogen sulfide, oxygen, and nitrogen. The gas phase hydrogen permeation chamber is equipped with an inlet pipe and an outlet pipe. The gas component control unit is connected to the inlet and outlet pipes of the gas phase hydrogen permeation cavity to form a closed-loop or semi-closed-loop gas circulation loop. The gas-phase hydrogen permeation chamber is connected to the first surface of the sample to be tested.

4. The hydrogen permeation testing apparatus for coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode as described in claim 1, characterized in that, The electrochemical hydrogen permeation unit includes a corrosive medium supply unit and an electrochemical hydrogen permeation chamber. The electrochemical hydrogen permeation chamber is provided with an inlet and an outlet. The corrosive medium supply unit is connected to the inlet and outlet of the electrochemical hydrogen permeation chamber to form a circulating or static mode. The corrosive medium supply unit is connected to a corrosive medium source, which includes an acidic solution containing carbon dioxide or hydrogen sulfide. The electrochemical hydrogen permeation chamber is disposed within the gas phase hydrogen permeation chamber of the gas phase hydrogen permeation unit, and the electrochemical hydrogen permeation chamber is connected to a local area of ​​the first surface of the sample to be tested.

5. The hydrogen permeation testing apparatus for coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode as described in claim 1, characterized in that, The hydrogen measurement module includes a hydrogen measurement electrolytic cell and a three-electrode electrochemical measurement unit connected in sequence. The hydrogen electrolytic cell is equipped with an alkaline electrolyte solution. The hydrogen electrolysis cell is sealed to the second surface of the sample to be tested; The three-electrode electrochemical measurement unit uses the second surface of the sample to be tested as the working electrode.

6. The hydrogen permeation testing apparatus for coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode as described in claim 1, characterized in that, It also includes a temperature and pressure control module, a data acquisition module, and an external load module; The temperature and pressure control module includes a heating device and a temperature and pressure control device, and the temperature and pressure control module is connected to the dual hydrogen source hydrogen permeation module and the hydrogen measurement module, respectively. The data acquisition module includes an electrochemical workstation, a potentiostat, a pressure sensor, a temperature sensor, and a mass flow controller; the data acquisition module is connected to the temperature and pressure control module, the dual hydrogen source hydrogen permeation module, and the hydrogen measurement module, respectively. The external load module is connected to the test sample.

7. A hydrogen permeation test method coupling gaseous hydrogen with hydrogen evolution at a corrosive cathode, characterized in that, The hydrogen permeation testing apparatus using the coupling of gaseous hydrogen and hydrogen evolution at a corrosive cathode as described in any one of claims 1 to 6 includes the following steps: (1) The sample to be tested is sealed and installed in the clamping module, with the first surface facing the dual hydrogen source hydrogen permeation module and the second surface facing the hydrogen measurement module; (2) Inject alkaline electrolyte into the hydrogen measurement module and construct a three-electrode system, and apply a constant anodic potential to the second surface of the sample to be tested for polarization; (3) Adjust the operation mode of the dual hydrogen source hydrogen permeation module and record the hydrogen permeation current-time curve through the data acquisition module; (4) Based on the obtained hydrogen permeation current-time curve, calculate the steady-state hydrogen permeation current density and perform coupling effect analysis; (5) Adjust the hydrogen permeation parameters, repeat steps (3) and (4), and establish hydrogen permeation behavior spectra of the test sample under different hydrogen permeation parameters.

8. The hydrogen permeation test method coupled with gaseous hydrogen and hydrogen evolution at a corrosive cathode as described in claim 7, characterized in that, The dual-hydrogen-source hydrogen permeation module operates in any of the following modes: Single electrochemical hydrogen permeation mode: Corrosive medium is injected into the electrochemical hydrogen permeation chamber and a cathode potential or natural corrosion potential is applied, while inert gas is introduced into the gas phase hydrogen permeation chamber to maintain pressure balance. Single gas phase hydrogen permeation mode: The gas phase hydrogen permeation chamber is filled with a hydrogen-containing mixed gas, while the electrochemical hydrogen permeation chamber is left empty; Dual-source coupled hydrogen permeation mode: A hydrogen-containing mixed gas is introduced into the gas phase hydrogen permeation chamber, while a corrosive medium is introduced into the electrochemical hydrogen permeation chamber and a potential is applied.

9. The hydrogen permeation test method coupled with hydrogen evolution from a corrosive cathode as described in claim 7, characterized in that, The coupling effect analysis is as follows: The steady-state hydrogen permeation current density of single electrochemical corrosion hydrogen permeation is obtained. J corr Steady-state hydrogen permeation current density of single-phase gaseous hydrogen dissociation and hydrogen permeation J gas Total steady-state hydrogen permeation current density under dual hydrogen source coupling conditions J total ; Compare J total and J corr + J gas Relationship: If J total > J corr + J gas When this occurs, it indicates the presence of a positive coupling enhancement effect; like J total < J corr + J gas When the value is 0, it indicates the presence of an inhibitory effect.

10. The hydrogen permeation test method coupled with hydrogen evolution from a corrosive cathode as described in claim 7, characterized in that, The second surface of the test sample is plated with a nickel plating or a palladium plating, and the plating thickness is 0.1~2μm; A constant anode potential is applied, which is +150 mV to +300 mV relative to the reference electrode; The hydrogen permeation parameters include temperature, gas composition, gas pressure, pH value of the corrosive medium, and cathode potential.

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