Hydrogen permeation experimental device and experimental method for metal pipe in actual service hydrogen environment

Abstract

The invention relates to experimental equipment and an experimental method, in particular to a hydrogen permeation experimental device and experimental method for a metal pipe in an actual service hydrogen environment, and the hydrogen permeation experimental device comprises a liquid phase space, a gas phase space, a metal pipe sample, electrochemical workstation detection equipment and corrosion monitoring equipment, the hydrogen pipeline is connected with a hydrogen gas source, gas in the hydrogen pipeline is in a flowing state, one end of the pipeline connector is connected to the side wall of the hydrogen pipeline, the other end of the pipeline connector is connected with the bottom of the liquid phase space, and the metal pipe sample is clamped between the pipeline connector and the bottom of the liquid phase space. A reference electrode and an auxiliary anode are arranged in the liquid phase space, and the reference electrode, the auxiliary anode and the metal pipe sample form a three-electrode body. According to the invention, the hydrogen permeation rule of the pipeline steel under the actual working condition can be more accurately simulated, and the accuracy of the test result is higher.

Description

Technical Field

[0001] The invention relates to an experimental device, in particular to a hydrogen permeation experimental device and an experimental method for a metal pipe in an actual service hydrogen environment. Background Art

[0002] Hydrogen energy storage and transportation has attracted much attention as a key link in the hydrogen energy application chain. Mixing hydrogen into natural gas pipelines and using existing long-distance pipelines and urban gas pipeline systems for long-distance transportation, terminal supply or dynamic storage is an important technical approach to solve the distributed development of hydrogen energy and low-cost storage and transportation. With the large-scale application of pipeline hydrogen transportation, the risk of hydrogen damage to pipes in service environments has gradually attracted attention. In recent years, domestic and foreign scholars have carried out a lot of research on the laws of hydrogen damage to pipeline steel.

[0003] At present, most gas-phase hydrogen permeation devices are small-scale devices operated in laboratories. They simulate the hydrogen permeation law in the gas-phase environment to a certain extent, but there are still certain differences between the state of pipeline steel in the actual service environment, which affects the results of the hydrogen permeation test. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a hydrogen permeation experimental device and an experimental method for metal pipes in an actual service hydrogen environment, which can more accurately simulate the hydrogen permeation law of pipeline steel under actual working conditions and have higher accuracy of test results.

[0005] In order to solve the above technical problems, this application provides the following technical solutions:

[0006] The present invention discloses a hydrogen permeation experimental device for metal pipes in an actual service hydrogen environment, comprising a liquid phase space, a gas phase space, a metal pipe sample, an electrochemical workstation detection device and a corrosion monitoring device, wherein the liquid phase space is located above the gas phase space, the liquid phase space is a closed cavity, the liquid phase space is filled with a hydrogen permeation liquid, the gas phase space comprises a hydrogen pipeline and a pipeline connector, the hydrogen pipeline is a service pipeline of a test platform, the hydrogen pipeline is connected to a hydrogen gas source, the gas in the hydrogen pipeline is in a flowing state, one end of the pipeline connector is connected to a side wall of the hydrogen pipeline, the other end of the pipeline connector is connected to the bottom of the liquid phase space, the metal pipe sample is clamped between the pipeline connector and the gas source, and the gas source is connected to the gas source. Between the bottom of the liquid phase space, one side of the metal pipe sample is in contact with the hydrogen in the gas phase space, and the other side of the metal pipe sample is in contact with the hydrogen permeation liquid in the liquid phase space. A reference electrode and an auxiliary anode are arranged in the liquid phase space. One end of the reference electrode and the auxiliary anode are connected to the hydrogen permeation liquid, and the other ends of the reference electrode, the auxiliary anode and the metal pipe sample are all connected to an electrochemical workstation detection device. The reference electrode, the auxiliary anode and the metal pipe sample constitute a three-electrode body. The corrosion monitoring device is connected to the side wall of the hydrogen pipeline, and is used for real-time online monitoring of the corrosion rate of the flowing gas in the hydrogen pipeline.

[0007] Compared with the prior art, the hydrogen permeation test device for metal pipes in actual service hydrogen environment of the present invention has at least the following beneficial effects:

[0008] The invention discloses a hydrogen permeation experimental device for metal pipes in an actual service hydrogen environment. The device comprises a gas phase space and a liquid phase space. The gas phase space comprises a hydrogen pipeline and a pipeline connector. The hydrogen pipeline is a service pipeline of a test platform. The hydrogen pipeline is connected to a hydrogen gas source. The gas in the hydrogen pipeline is in a flowing state. The gas state in the hydrogen pipeline is the same as the gas flow state in the hydrogen pipeline in an actual service environment. The gas in the hydrogen pipeline has the same impurity content as the gas in the actual service environment. Therefore, the hydrogen permeation law of pipeline steel in actual working conditions can be simulated more accurately, and the accuracy of the test results can be improved. The corrosion monitoring equipment can realize real-time online monitoring of the corrosion rate of pipeline flowing gas with an accuracy of up to 0.01 μm / a. At the same time, the pipeline connector is connected to the side wall of the hydrogen pipeline, and the metal pipe sample is clamped between the pipeline connector and the liquid phase space. Therefore, the metal pipe sample is on the side of the flowing hydrogen-containing gas, which is the same as the position of the pipeline steel in actual working conditions, and the accuracy of the test results is further improved.

[0009] The hydrogen permeation test device for metal pipes in actual service hydrogen environment of the present invention will be further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic cross-sectional structure diagram of a hydrogen permeation test device for metal pipes in an actual service hydrogen environment of the present invention;

[0011] Figure 2 It is a schematic diagram of the three-dimensional structure of the hydrogen permeation experimental device for metal pipes in the actual service hydrogen environment of the present invention;

[0012] Figure 3 It is a cross-sectional view of a tubular body in a hydrogen permeation test device for a metal pipe in an actual service hydrogen environment of the present invention;

[0013] Figure 4 It is a schematic diagram of the three-dimensional structure of the tubular body in the hydrogen permeation experimental device of the metal pipe in the actual service hydrogen environment of the present invention. DETAILED DESCRIPTION

[0014] like Figure 1 , Figure 2As shown, the present invention provides a hydrogen permeation experimental device and experimental method for metal pipes in actual service hydrogen environment, including a liquid phase space, a gas phase space, a metal pipe sample 21, an electrochemical workstation detection device, and a corrosion monitoring device 71. The liquid phase space is located above the gas phase space, and the liquid phase space is a closed cavity. The liquid phase space is filled with a hydrogen permeation liquid. The hydrogen permeation liquid adopts 0.1 mol / L NaOH solution or other alkaline solution, the gas phase space includes a hydrogen pipeline 11 and a pipeline connector 12, the hydrogen pipeline 11 is a service pipeline of the test platform, the hydrogen pipeline 11 is connected to a hydrogen gas source, the gas in the hydrogen pipeline 11 is in a flowing state, the gas flow state in the hydrogen pipeline 11 is the same as the gas flow state in the hydrogen pipeline under the actual service environment, the gas in the hydrogen pipeline 11 has the same impurity content as the gas under the actual service environment, one end of the pipeline connector 12 is connected to the side wall of the hydrogen pipeline 11, and the other end of the pipeline connector 12 is connected to the bottom of the liquid phase space, the metal pipe sample 21 is clamped between the pipeline connector 12 and the bottom of the liquid phase space, the metal pipe sample 21 is in the shape of a thin plate, one side of the metal pipe sample 21 is a working surface, and the other side is a test surface, the metal pipe The working surface of the sample 21 contacts the hydrogen in the gas phase space, and the test surface of the metal pipe sample 21 contacts the hydrogen permeation liquid in the liquid phase space to form a hydrogen measuring electrolytic cell. A reference electrode 41 and an auxiliary anode 42 are provided in the liquid phase space. One end of the reference electrode 41 and the auxiliary anode 42 are connected to the hydrogen permeation liquid, and the other end of the reference electrode 41, the other end of the auxiliary anode 42, and the other end of the metal pipe sample 21 are all connected to the electrochemical workstation detection equipment. In this embodiment, the electrochemical workstation detection equipment adopts a portable constant potential current tester detection equipment. The reference electrode 41, the auxiliary anode 42, and the metal pipe sample 21 constitute a three-electrode body. The corrosion monitoring equipment 71 is connected to the side wall of the hydrogen pipeline 11. The corrosion monitoring equipment 71 is used to monitor the corrosion rate of the flowing gas in the hydrogen pipeline 11 in real time online. The three electrodes are connected to the portable constant potential current tester detection equipment to remotely monitor the current change law in real time. The test accuracy can reach 10nA, which meets the requirements of hydrogen permeation test in the gas phase environment. Specifically, flanges are provided at both ends of the hydrogen pipeline 11, and the flanges at the ends of the hydrogen pipeline 11 are connected to the field platform through flanges 61 and 62, and the flanges are connected by bolts 63. A high-pressure sealing gasket 64 is provided on the flanges at the ends of the hydrogen pipeline 11; the flanges 61 and 62 are installed with blind plates to meet laboratory testing, and can be disassembled to meet field service experimental platform testing. The hydrogen pipeline 11 is made of 316L stainless steel, and the reference electrode 41 is immersed in the salt bridge, which acts as a passage, and the reference electrode 41, the auxiliary anode 42, and the metal pipe sample 21 form a three-electrode system. The metal pipe sample can be various steel pipes in field service. The portable constant potential current tester detection equipment is the abbreviation of the electrochemical measurement system, which is an electronic instrument that controls the potential difference between the working electrode and the reference electrode.Among them, the working electrode and the reference electrode are both components of the electrochemical electrolytic cell. The automatic monitoring portable constant potential current tester detection equipment controls the potential difference between the working electrode and the reference electrode by injecting potential into the auxiliary electrode or the counter electrode. The present invention provides a hydrogen permeation experimental device for metal pipes in an actual service hydrogen environment. Since it includes a gas phase space and a liquid phase space, the gas phase space includes a hydrogen pipeline 11 and a pipeline connector 12. The hydrogen pipeline 11 is a service pipeline of the test platform. The hydrogen pipeline 11 is connected to a hydrogen gas source. The gas in the hydrogen pipeline 11 is in a flowing state. The gas state in the hydrogen pipeline 11 is the same as the gas flow state in the hydrogen pipeline under the actual service environment. The gas in the hydrogen pipeline 11 has the same impurity content as the gas in the actual service environment. Therefore It can more accurately simulate the hydrogen permeation law of pipeline steel under actual working conditions and improve the accuracy of test results. The corrosion monitoring equipment can realize real-time online monitoring of the corrosion rate of pipeline flowing gas with an accuracy of up to 0.01μm / a. At the same time, the pipeline connector 12 is connected to the side wall of the hydrogen pipeline 11, and the metal pipe sample 21 is clamped between the pipeline connector 12 and the liquid phase space. Therefore, the metal pipe sample 21 is on the side of the flowing hydrogen-containing gas, which is the same as the position of the pipeline steel under actual working conditions, further improving the accuracy of the test results.

[0015] Alternatively, if Figure 3 , Figure 4 As shown, the liquid phase space includes a tubular body 31 with an open bottom, a receiving groove 311 is provided on one end surface of the tubular body 31 close to the pipe connector 12, and an annular boss 121 is provided on one end surface of the pipe connector 12 close to the liquid phase space, the annular boss 121 is accommodated in the receiving groove 311, and the metal pipe sample 21 is clamped between the receiving groove 311 and the annular boss 121. The shape and size of the receiving groove 311 match the shape and size of the metal pipe sample 21, and the metal pipe sample 21 is clamped between the receiving groove 311 and the annular boss 121 to ensure the sealing and insulation of the experiment, and to prevent the hydrogen permeation liquid in the liquid phase space from infiltrating into the gas phase space and affecting the test results.

[0016] Optionally, a first sealing device 51 and a second sealing device 52 are also included. The first sealing device 51 is arranged between the receiving groove 311 and the metal pipe sample 21, and the second sealing device 52 is arranged between the annular boss 121 and the metal pipe sample 21. Specifically, the first sealing device 51 and the second sealing device 52 both use sealing rings, and the material is PEEK material, which can withstand pressure and temperature and is not easy to deform, to ensure that the metal pipe sample 21 is insulated from the gas phase space and the liquid phase space, and can ensure sealing at a high pressure of 10MPa. Since the gas state in the hydrogen pipeline 11 is the same as the gas flow state in the hydrogen pipeline under the actual service environment, the hydrogen pipeline 11 is in a high pressure state, and an absolutely closed space is formed by the first sealing device and the second sealing device, which can prevent gas leakage under high pressure.

[0017] Optionally, it also includes a support plate and a support pressure plate, both of which are porous plates, and the support pressure plate and the support plate are respectively arranged on the upper and lower sides of the metal pipe sample 21, and the support pressure plate, the metal pipe sample 21, and the support plate are clamped from top to bottom between the accommodating groove 311 and the annular boss 121 to prevent the metal pipe sample 21 from being deformed due to hydrogen filling in the hydrogen pipeline 12.

[0018] Optionally, a penetration hole 312 is further provided on an end surface of the tubular body 31 close to the pipeline connector 12 . The aperture of the penetration hole 312 is smaller than the inner diameter of the tubular body 31 , and the penetration hole 312 is communicated with the containing groove 311 .

[0019] Optionally, the liquid phase space further includes a first connecting flange 32, and a second connecting flange 313 is provided on the end surface of the tubular body 31 away from the pipeline connector 12. The first connecting flange 32 and the second connecting flange 313 are connected to each other by a plurality of bolts to form a closed cavity.

[0020] Optionally, a third connecting flange 314 is provided at one end of the tubular body 31 close to the pipe connector 12, and a fourth connecting flange 122 is provided at one end of the pipe connector 12 connected to the tubular body 31, and the tubular body 31 and the pipe connector 12 are connected via the third connecting flange 314 and the fourth connecting flange 122.

[0021] Optionally, an exhaust pipe 111 is provided on the hydrogen pipeline 11, and an outlet valve 112 and a safety valve are provided on the exhaust pipe 111. A pressure transmitter and a pressure gauge recorder are also provided on the hydrogen pipeline 11. Different pressure environments are obtained in the gas phase space through the pressure transmitter, so that hydrogen permeation curves under different pressure environments are obtained through samples.

[0022] The experimental method for conducting a hydrogen permeation experiment using a hydrogen permeation experimental device for a metal pipe in a field actual service hydrogen environment of the present invention comprises the following steps:

[0023] First, N2 is introduced into the hydrogen pipeline 11 and released through the outlet valve 112 on the exhaust pipe 111. This is repeated several times. Then, a vacuum device is used to remove impurity gases in the gas phase space. A 0.1 mol / L NaOH solution is injected into the liquid phase space. The tubular body 31 is connected to the pipeline connector 12. The metal pipe sample 21 is clamped between the receiving groove 311 and the annular boss 121.

[0024] Then, the electrochemical workstation was set to a constant potential, and the test surface of the metal pipe sample 21 was kept at +300 mV. SCEThe electrochemical workstation software program connected to the metal pipe sample 21 shows the curve of the anode current changing with time. When the background current density is lower than 100 nA cm -2 After that, hydrogen is injected into the gas phase space on one side of the working surface of the metal pipe sample 21, and a constant hydrogen pressure of different pressure values ​​is applied to the hydrogen pipeline 11 through the pressure transmitter on the hydrogen pipeline 11. The time when the hydrogen pressure is applied is recorded and continued until the predetermined time. After the experiment, the background current and the time before the cathode current is applied are removed to obtain the hydrogen permeation curve. During the experiment, the portable constant potential current tester detection equipment is always used to continuously record the curve of the current change over time. After the experiment, the background current and the time before the cathode current are applied are removed to obtain the hydrogen permeation curve of the metal pipe sample 21.

[0025] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A hydrogen permeation test device for metal pipes in actual service hydrogen environment, characterized in that: The invention comprises a liquid phase space, a gas phase space, a metal pipe sample (21), an electrochemical workstation detection device, and a corrosion monitoring device (71). The liquid phase space is located above the gas phase space. The liquid phase space is a closed cavity. The liquid phase space is filled with hydrogen permeation liquid. The gas phase space comprises a hydrogen pipeline (11) and a pipeline connector (12). The hydrogen pipeline (11) is a service pipeline of the test platform. The hydrogen pipeline (11) is connected to a hydrogen gas source. The gas in the hydrogen pipeline (11) is in a flowing state. One end of the pipeline connector (12) is connected to the side wall of the hydrogen pipeline (11), and the other end of the pipeline connector (12) is connected to the bottom of the liquid phase space. The metal pipe sample (21) is clamped between the pipeline connector (12) and the bottom of the liquid phase space. The metal pipe sample (21) is 1) One side of the metal pipe sample (21) is in contact with the hydrogen in the gas phase space, and the other side of the metal pipe sample (21) is in contact with the hydrogen permeation liquid in the liquid phase space. A reference electrode (41) and an auxiliary anode (42) are arranged in the liquid phase space. One end of the reference electrode (41) and the auxiliary anode (42) are connected to the hydrogen permeation liquid, and the other end of the reference electrode (41), the other end of the auxiliary anode (42), and the other end of the metal pipe sample (21) are all connected to an electrochemical workstation detection device. The reference electrode (41), the auxiliary anode (42), and the metal pipe sample (21) constitute a three-electrode body. The corrosion monitoring device (71) is connected to the side wall of the hydrogen pipeline (11). The corrosion monitoring device (71) is used to monitor the corrosion rate of the flowing gas in the hydrogen pipeline (11) in real time online.

2. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 1, characterized in that: The liquid phase space comprises a tubular body (31) with an open bottom, a receiving groove (311) is arranged on an end surface of the tubular body (31) close to the pipe connector (12), the receiving groove (311) matches the metal pipe sample (21), and an annular boss (121) is arranged on an end surface of the pipe connector (12) close to the liquid phase space, the annular boss (121) is accommodated in the receiving groove (311), and the metal pipe sample (21) is clamped between the receiving groove (311) and the annular boss (121).

3. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 2, characterized in that: It also includes a first sealing device (51) and a second sealing device (52), wherein the first sealing device (51) is arranged between the receiving groove (311) and the metal pipe sample (21), and the second sealing device (52) is arranged between the annular boss (121) and the metal pipe sample (21), and the first sealing device (51) and the second sealing device (52) are made of PEEK material.

4. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 1, characterized in that: It also includes a support plate and a support pressure plate, wherein the support pressure plate and the support plate are both porous plates, and the support pressure plate and the support plate are respectively arranged on both sides of the metal pipe sample (21).

5. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 3, characterized in that: A penetration hole (312) is also provided on an end surface of the tubular body (31) close to the pipeline connector (12); the diameter of the penetration hole (312) is smaller than the inner diameter of the tubular body (31); and the penetration hole (312) is connected to the containing groove (311).

6. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 5, characterized in that: The liquid phase space further comprises a first connecting flange (32), and a second connecting flange (313) is arranged on an end surface of the tubular body (31) away from the pipeline connector (12), and the first connecting flange (32) and the second connecting flange (313) are connected to each other to form the closed cavity.

7. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 6, characterized in that: A third connecting flange (314) is provided at one end of the tubular body (31) close to the pipeline connector (12), and a fourth connecting flange (122) is provided at one end of the pipeline connector (12) connected to the tubular body (31); the tubular body (31) and the pipeline connector (12) are connected via the third connecting flange (314) and the fourth connecting flange (122).

8. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 1, characterized in that: The hydrogen pipeline (11) is provided with an exhaust pipe (111), and the exhaust pipe (111) is provided with an outlet valve (112) and a safety valve.

9. The hydrogen permeation test device for metal pipes in actual service hydrogen environment according to claim 8, characterized in that: The hydrogen pipeline (11) is also provided with a pressure transmitter and a pressure gauge recorder.

10. The method for conducting an experiment on the hydrogen permeation test device for metal pipes in an actual service hydrogen environment according to any one of claims 1 to 9, characterized in that: The steps include: Then, a constant potential is set by the electrochemical workstation, and the test surface of the metal pipe sample (21) is kept at +300 mV. SCE The electrochemical workstation connected to the metal pipe sample (21) shows a curve of the anode current changing with time. When the background current density is lower than 100 nA·cm -2 Then, hydrogen is injected into the gas phase space on one side of the working surface of the metal pipe sample (21), and a constant hydrogen pressure of different pressure values ​​is applied to the hydrogen pipeline (11). The time when the hydrogen pressure starts to be applied is recorded and continued until a predetermined time. After the experiment is completed, the background current and the time before the cathode current is applied are removed to obtain the hydrogen permeation curve.

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