Experimental device for measuring high-pressure hydrogen permeation behavior in gaseous or gas-liquid mixed state and test method thereof

Abstract

The present application relates to a kind of experimental apparatus and its test method for measuring gaseous or gas-liquid mixed state high-pressure hydrogen permeation behavior, wherein the experimental apparatus for measuring gaseous or gas-liquid mixed state high-pressure hydrogen permeation behavior includes autoclave, collet joint, pressure reducing valve, exhaust valve, high-pressure hydrogen cylinder, autoclave and electrolytic cell connecting device, electrolytic cell, experimental electrode, electrochemical workstation and strain gauge tester;Two threaded through holes are arranged in the middle position of the cover of the autoclave on the upper side, and the two threaded through holes are respectively connected with collet joint, collet joint connects conduit, two conduits are respectively connected with pressure reducing valve and exhaust valve, and the pressure reducing valve is connected with high-pressure cylinder by another conduit;Round channel is arranged in the middle of autoclave body, and the present application can change gas component, gas partial pressure, gas-liquid mixing and the like conditions, to provide corresponding experimental technical support for the selection of natural gas hydrogen blending pipeline pipe material, process design and safety management.

Description

TECHNICAL FIELD

[0001] The present application belongs to the experimental device for testing hydrogen permeation behavior, and particularly relates to an experimental device and a test method for measuring high-pressure hydrogen permeation behavior in gaseous or gas-liquid mixed state. BACKGROUND

[0002] At present, many countries in the world are developing hydrogen storage and utilization technologies. Among the existing hydrogen energy storage and transportation technologies, the use of existing natural gas pipeline network to transport hydrogen in the form of hydrogen-doped natural gas is the most economical. In the key technology of hydrogen pipeline transportation, pipeline material evaluation is the research basis and is the key to compatibility evaluation of hydrogen-doped natural gas transportation. The pipeline steel may be deteriorated or even failed in the hydrogen environment. Hydrogen molecules in the pipeline collide with the surface of the steel and are adsorbed on the surface of the steel. Then, the hydrogen molecules penetrate into the steel in the form of atoms, causing hydrogen embrittlement, hydrogen-induced cracking, hydrogen blistering and other hydrogen damage phenomena of the pipeline steel, resulting in pipeline cracking and thus gas leakage or even explosion, affecting the safety along the pipeline and property safety. Therefore, the performance of the gas pipeline and the supporting materials under high-pressure hydrogen mixed gas is an important factor for determining the hydrogen-doped natural gas transportation.

[0003] At present, most of the researches on the hydrogen embrittlement problem of pipeline steel are carried out in a liquid hydrogen charging environment. Since the mechanism of hydrogen entering the steel in the liquid hydrogen charging environment and in the high-pressure hydrogen environment is not the same, the research in the liquid hydrogen charging environment cannot truly reflect the hydrogen permeation behavior occurring under actual working conditions. SUMMARY

[0004] In view of the above shortcomings of the prior art, the purpose of the present application is to provide an experimental device for measuring high-pressure hydrogen permeation behavior in gaseous or gas-liquid mixed state and a test method thereof. The experimental device for measuring high-pressure hydrogen permeation behavior in gaseous or gas-liquid mixed state can provide corresponding experimental technical support for the selection of pipeline materials, process design and safety management of hydrogen-doped natural gas transportation pipelines.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] The experimental device for measuring high-pressure hydrogen permeation behavior in gaseous or gas-liquid mixed state according to the present application is characterized by comprising a high-pressure autoclave, a collet joint, a pressure reducing valve, an exhaust valve, a high-pressure hydrogen cylinder, a connecting device of the high-pressure autoclave and an electrolytic cell, an electrolytic cell, an experimental electrode, an electrochemical workstation and a strain gauge tester.

[0007] Two threaded through holes are arranged in the middle position of the autoclave cover on the upper side of the autoclave, the two threaded through holes are respectively connected with a sleeve joint, the sleeve joint is connected with a conduit, the two conduits are respectively connected with a pressure reducing valve and an exhaust valve, the pressure reducing valve is connected with a high-pressure gas cylinder through another conduit; A circular channel is arranged in the middle of the autoclave body, the outlet end of the circular channel is connected with a connecting device with a central channel, the connecting device is divided into two detachable parts, the first part of the connecting device is connected with the circular channel of the autoclave, the second part of the connecting device is connected with the electrolytic cell, the first part of the connecting device has a first recess, the second part of the connecting device has a first boss matched with the first recess, a first gasket is placed on the bottom of the first recess and a test sample, one side of the test sample has an electroplated layer, a strain gauge is connected on the electroplated layer, the strain gauge is electrically connected with a strain gauge tester outside the connecting device body, wherein the side of the test sample with the electroplated layer faces the electrolytic cell.

[0008] A second recess is arranged on the second part of the connecting device, a second boss matched with the second recess is arranged on the electrolytic cell, and a second gasket is arranged in the second recess to block the communication between the electrolytic cell and the central channel.

[0009] A solution and an experimental electrode are arranged in the electrolytic cell, and the extending end of the experimental electrode is electrically connected with an electrochemical workstation.

[0010] Further, the above-mentioned circular channel has an internal thread, and the protruding column of the first part of the connecting device has an external thread threadedly connected with the internal thread of the circular channel.

[0011] Further, the first part and the second part of the connecting device are fixedly connected through bolts.

[0012] Further, the first gasket and the second gasket are made of polytetrafluoroethylene material.

[0013] Further, the autoclave and the autoclave cover are made of stainless steel material, the autoclave cover is connected with the autoclave through embedding connection, the inner diameter of the autoclave is one hundred millimeters, and the internal space height is two hundred millimeters.

[0014] Further, the sleeve joint and the autoclave cover are connected through threads, and the sealing is increased by thread glue.

[0015] Further, the experimental electrode is a platinum electrode and a saturated calomel electrode.

[0016] The test method for measuring the permeation behavior of gaseous or gas-liquid mixed state high-pressure hydrogen is characterized in that:

[0017] The method steps are as follows:

[0018] Step one: simulate different working conditions, and use different hydrogen concentrations;

[0019] Step two: after polishing both sides of the sample, use the electrochemical workstation to measure the hydrogen side of the sample and perform nickel plating treatment, and after completing the nickel plating, paste the strain gauge on the nickel plated surface;

[0020] Step three: place the first gasket at the bottom of the first sink of the connecting device, then place the sample with the strain gauge pasted on the first gasket near the autoclave, with the side of the sample without nickel plating facing the autoclave, fix the first and second parts of the connecting device with bolts and nuts to achieve the purpose of fixing the first gasket and the sample, after installation, purge the autoclave with 1 MPa nitrogen gas for 3 times to exhaust the air in the autoclave, and finally test the airtightness of the autoclave with nitrogen gas;

[0021] Step four: connect the strain gauge to the strain gauge tester through the wire, add 0.5 mol / L H2SO4 solution or pure hydrogen gas to the autoclave according to the experimental requirements, the hydrogen pressure is 1 MPa, 3 MPa, 5 MPa, 7 MPa and 10 MPa respectively, and the stress value on the nickel plated surface of the sample is measured by the strain gauge tester;

[0022] Step five: after completing the stress measurement experiment, open the exhaust valve, treat the tail gas, and replace the sample used in the previous experiment with a sample that has completed nickel plating treatment but has not pasted a strain gauge, after installation, purge the autoclave with 1 MPa nitrogen gas for 3 times to exhaust the air in the autoclave, and finally test the airtightness of the autoclave with nitrogen gas;

[0023] Step six: after completing the airtightness test, connect the electrolytic cell to the connecting device, place the second gasket in the second sink to prevent solution from leaking, add 0.1 mol / L NaOH solution to the electrolytic cell, and place the platinum electrode and saturated calomel electrode into the solution as auxiliary electrodes, the platinum electrode as a reference electrode and the sample as a working electrode are respectively connected to the electrochemical workstation, and the electrochemical workstation is turned on to start anodic polarization to reduce the background current;

[0024] Step seven: after the background current is reduced to meet the experimental requirements and is stable, add 0.5 mol / L H2SO4 solution and nitrogen or pure hydrogen to the autoclave according to the experimental requirements, and the pressure of nitrogen and hydrogen is 1 MPa, 3 MPa, 5 MPa, 7 MPa and 10 MPa respectively;

[0025] Step eight: after the hydrogen permeation current measurement experiment is completed, open the exhaust valve, treat the tail gas, remove the electrolytic cell to treat the waste liquid, and take out the sample.

[0026] The application is an experimental device which can simulate hydrogen permeation behavior of pipeline steel under different hydrogen mixing conditions by changing gas component, gas partial pressure, gas-liquid mixing and the like, simulate hydrogen permeation behavior of pipeline steel under different hydrogen mixing conditions, measure stress distribution of the material through a strain gauge system, analyze the influence of different hydrogen mixing conditions on hydrogen permeation behavior of the material through electrochemical experimental results, and thus provide corresponding experimental technical support for material selection, process design and safety management of hydrogen mixed natural gas transmission pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a schematic diagram of the experimental device of the application;

[0028] Figure 2 schematic diagram of the autoclave during stress testing;

[0029] Figure 3 partial enlarged view of the connecting device during stress testing;

[0030] Figure 4 schematic diagram of the autoclave during hydrogen permeation testing;

[0031] Figure 5 partial enlarged view of the connecting device during hydrogen permeation testing;

[0032] Figure 6 schematic diagram of the strain gauge sticking;

[0033] The marks in the figure are as follows: 1, high-pressure gas cylinder; 2, pressure reducing valve; 3, exhaust valve; 4, collet joint; 5, autoclave; 6, connecting device; 7, electrolytic cell; 8, platinum electrode; 9, saturated mercury electrode; 10, electrochemical workstation; 11, O-ring; 12, first gasket; 13, strain gauge; 14, sample; 15, second gasket;

[0034] 601, first part; 602, second part; 603, first sink groove; 604, first boss; 605, second sink groove; 606, second boss; 501, internal thread. DETAILED DESCRIPTION

[0035] The application will be further described below in combination with the drawings and examples.

[0036] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0037] The experimental device for measuring the high-pressure hydrogen permeation behavior of gaseous or gas-liquid mixed state includes a high-pressure kettle 5, a sleeve joint 4, a pressure reducing valve 2, an exhaust valve 3, a high-pressure hydrogen cylinder 1, a connecting device 6 of the high-pressure kettle and an electrolytic cell, an electrolytic cell 7, an experimental electrode, an electrochemical workstation 10 and a strain gauge tester (not shown in the figure).

[0038] Two threaded holes are arranged in the middle of the kettle cover on the upper side of the high-pressure kettle 5, and the sleeve joint 4 is connected to the threaded holes, and the sleeve joint is connected to the kettle cover through threads and is sealed by thread glue; the sleeve joint is connected to the pipes, and the two pipes are connected to the pressure reducing valve 2 and the exhaust valve 3 respectively, and the pressure reducing valve 2 is connected to the high-pressure cylinder 1 through another pipe; a circular channel is arranged in the middle of the kettle body of the high-pressure kettle 5, and the outlet end of the circular channel is connected to the connecting device 6 with a central channel, and the connecting device 6 is divided into two detachable parts, which are the first part 601 and the second part 602 of the connecting device, and the first part 601 and the second part 602 are fixed by bolt locking.

[0039] The first part 601 of the connecting device is connected to the circular channel of the high-pressure kettle (the circular channel has an internal thread 501, the convex column of the first part of the connecting device has an external thread for thread connection with the internal thread of the circular channel, an O-ring 11 is arranged on the convex column of the first part of the connecting device, the second part 602 of the connecting device is connected to the electrolytic cell 7, the first part of the connecting device has a first recess 603, the second part of the connecting device has a first boss 604 matched with the first recess, the first gasket 12 and the sample 14 are placed on the bottom of the first recess, one side of the sample has an electroplated layer, and the strain gauge 13 is connected to the electroplated layer, and the strain gauge is electrically connected to the strain gauge tester outside the connecting device body, wherein the side of the sample with the electroplated layer faces the electrolytic cell.

[0040] A second recess 605 is arranged on the second part of the connecting device, and a second boss 606 matched with the second recess is arranged on the electrolytic cell, and a second gasket 15 is arranged in the second recess to block the communication between the electrolytic cell and the central channel.

[0041] The electrolytic cell is provided with a solution, a platinum electrode and a saturated calomel electrode, and the extension end of the experimental electrode is electrically connected to the electrochemical workstation.

[0042] Specifically, the first gasket and the second gasket are made of polytetrafluoroethylene material, the high-pressure kettle and the kettle cover of the high-pressure kettle are made of stainless steel material, the kettle cover of the high-pressure kettle is connected to the high-pressure kettle in an embedded connection mode, the inner diameter of the high-pressure kettle is one hundred millimeters, and the internal space height is two hundred millimeters.

[0043] The test method for measuring the high-pressure hydrogen permeation behavior of gaseous or gas-liquid mixed state,

[0044] The method steps are as follows:

[0045] Step one: simulate different working conditions, adopt different hydrogen concentration;

[0046] Step two: polish both sides of the sample, then use the electrochemical workstation to measure the hydrogen side of the sample and perform nickel plating treatment, after which the strain gauge is pasted on the nickel-plated surface;

[0047] Step three: place the first gasket at the bottom of the first sink of the connecting device, then place the sample with the strain gauge pasted on it on the first gasket near the autoclave, with the side without nickel plating facing the autoclave, fix the first and second parts of the connecting device with bolts and nuts to achieve the purpose of fixing the first gasket and the sample, after installation, blow the autoclave with 1 MPa nitrogen for 3 times to exhaust the air in the autoclave, and finally test the airtightness of the autoclave with nitrogen;

[0048] Step four: connect the strain gauge to the strain gauge tester through the wire, add 0.5 mol / L H2SO4 solution or pure hydrogen into the autoclave according to the experimental requirements, the hydrogen pressure is 1 MPa, 3 MPa, 5 MPa, 7 MPa, and 10 MPa respectively, and the stress value on the nickel-plated surface of the sample is measured by the strain gauge tester;

[0049] Step five: after completing the stress measurement experiment, open the exhaust valve, treat the tail gas, and replace the sample used in the previous experiment with a sample that has completed nickel plating treatment but has not pasted a strain gauge, after installation, blow the autoclave with 1 MPa nitrogen for 3 times to exhaust the air in the autoclave, and finally test the airtightness of the autoclave with nitrogen;

[0050] Step six: after completing the airtightness test, connect the electrolytic cell to the connecting device, place the second gasket in the second sink to prevent solution from leaking, add 0.1 mol / L NaOH solution to the electrolytic cell, and place the platinum electrode and saturated calomel electrode into the solution as auxiliary and reference electrodes respectively, and connect the sample as the working electrode to the electrochemical workstation, turn on the electrochemical workstation to start anodic polarization and reduce the background current;

[0051] Step seven: after the background current is reduced to meet the experimental requirements and is stable, add 0.5 mol / L H2SO4 solution and nitrogen or pure hydrogen to the autoclave according to the experimental requirements, the pressure of nitrogen and hydrogen is 1 MPa, 3 MPa, 5 MPa, 7 MPa, and 10 MPa respectively;

[0052] Step eight: after the hydrogen permeation current measurement experiment is completed, open the exhaust valve, treat the tail gas, remove the electrolytic cell to treat the waste liquid, and take out the sample.

[0053] The application is an experimental device which can simulate hydrogen permeation behavior of pipeline steel under different hydrogen mixing conditions by changing gas component, gas partial pressure, gas-liquid mixing and the like, simulate hydrogen permeation behavior of pipeline steel under different hydrogen mixing conditions, measure stress distribution of the material through a strain gauge system, analyze influence of different hydrogen mixing conditions on hydrogen permeation behavior of the material through electrochemical experimental results, and thus provide corresponding experimental technical support for material selection, process design and safety management of a hydrogen mixed natural gas conveying pipeline.

[0054] The above specific embodiments further explain the inventive purpose, technical scheme and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture, characterized in that: Includes a high-pressure autoclave (5), a compression fitting (4), a pressure reducing valve (2), an exhaust valve (3), a high-pressure hydrogen cylinder (1), a connection device between the high-pressure autoclave and the electrolytic cell (6), an electrolytic cell (7), experimental electrodes, an electrochemical workstation (10), and a strain gauge tester; Two threaded through holes are provided in the middle of the lid on the upper side of the high pressure vessel (5). The two threaded through holes are respectively connected to ferrule connectors (4). The ferrule connectors are connected to conduits. The two conduits are respectively connected to pressure reducing valve (2) and exhaust valve (3). The pressure reducing valve (2) is connected to the high pressure hydrogen cylinder (1) through another conduit. A circular channel is provided in the middle of the body of the high pressure vessel (5). The outlet end of the circular channel is connected to a connecting device (6) with a central channel. The connecting device (6) is divided into two detachable parts. The first part (60) of the connecting device is... 1) Connected to the circular channel of the high pressure vessel, the second part (602) of the connecting device is connected to the electrolytic cell (7), the first part of the connecting device has a first settling tank (603), the second part of the connecting device has a first boss (604) that matches the first settling tank, the bottom of the first settling tank is placed with a first gasket (12) and a sample (14), one side of the sample has an electroplated layer, and a strain gauge (13) is connected on the electroplated layer. The strain gauge is electrically connected to a strain gauge tester located outside the connecting device, wherein the side of the sample with the electroplated layer faces the electrolytic cell. The second part of the connecting device is provided with a second sink (605), the electrolytic cell is provided with a second boss (606) that matches the second sink, and a second gasket (15) is provided in the second sink to block the connection between the electrolytic cell and the central channel. The electrolytic cell contains a solution and experimental electrodes, and the protruding ends of the experimental electrodes are electrically connected to the electrochemical workstation.

2. The experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture according to claim 1, characterized in that: The circular channel has an internal thread (501), and the protrusion of the first part of the connecting device has an external thread that is threadedly connected to the internal thread of the circular channel. An O-ring (11) is provided on the protrusion of the first part of the connecting device.

3. The experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture according to claim 1, characterized in that: The first part (601) and the second part (602) of the connecting device are locked together by bolts.

4. The experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture according to claim 1, characterized in that: The first and second washers are made of polytetrafluoroethylene.

5. The experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture according to claim 1, characterized in that: The pressure vessel and its lid are made of stainless steel. The pressure vessel lid is connected to the pressure vessel by an embedded connection. The pressure vessel has an inner diameter of 100 mm and an internal height of 200 mm.

6. The experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture according to claim 1, characterized in that: The ferrule is connected to the autoclave lid by threads, and the seal is enhanced by thread sealant.

7. The experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture according to claim 1, characterized in that: The experimental electrodes were a platinum electrode and a saturated calomel electrode.

8. A test method for an experimental apparatus for measuring the high-pressure hydrogen permeation behavior in a gaseous or gas-liquid mixture as described in any one of claims 1-7, characterized in that: The steps are as follows: Step 1: Simulate different operating conditions using different hydrogen concentrations; Step 2: After polishing both sides of the sample, use an electrochemical workstation to plate the hydrogen measuring surface of the sample with nickel. After the nickel plating is completed, attach the strain gauge to the nickel-plated surface. Step 3: Place the first washer at the bottom of the first settling tank of the connecting device, and then place the sample with the strain gauge attached on the side of the first washer close to the autoclave, with the side of the sample without nickel plating facing the autoclave. Fix the first part and the second part of the connecting device with bolts and nuts to fix the first washer and the sample. After installation, purge the autoclave three times with 1MPa nitrogen to remove the air inside the autoclave. Finally, use nitrogen to test the airtightness of the autoclave. Step 4: Connect the strain gauge to the strain gauge tester via wires. Add 0.5 mol / L H2SO4 solution or pure hydrogen gas to the autoclave according to the experimental requirements. The hydrogen gas pressures are 1 MPa, 3 MPa, 5 MPa, 7 MPa, and 10 MPa, respectively. Use the strain gauge tester to measure the stress value on the nickel-plated surface of the sample. Step 5: After completing the stress measurement experiment, open the exhaust valve to treat the exhaust gas, and then replace the previously used sample with a sample that has been nickel-plated but has not had strain gauges attached. After installation, purge the autoclave three times with 1MPa nitrogen to remove the air inside the autoclave. Finally, use nitrogen to test the airtightness of the autoclave. Step 6: After completing the airtightness test, connect the electrolytic cell to the connecting device, place the second gasket in the second settling tank to prevent solution leakage, add 0.1 mol / L NaOH solution to the electrolytic cell, place the platinum electrode and saturated calomel electrode in the solution, connect the platinum electrode as the auxiliary electrode, the saturated calomel electrode as the reference electrode and the sample as the working electrode to the electrochemical workstation respectively, turn on the electrochemical workstation to start anodic polarization and reduce the background current; Step 7: After the background current drops to meet the experimental requirements and stabilizes, add 0.5 mol / L H2SO4 solution and nitrogen or pure hydrogen to the autoclave according to the experimental requirements. The pressures of nitrogen and hydrogen are 1 MPa, 3 MPa, 5 MPa, 7 MPa and 10 MPa, respectively. Step 8: After the hydrogen permeation current measurement experiment is completed, open the exhaust valve, treat the exhaust gas, remove the waste liquid from the electrolytic cell, and take out the sample.

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