Method and device for measuring hydrogen permeation rule of nonmetal along thickness direction

Abstract

The invention relates to the technical field of gas permeability testing, in particular to a method and device for measuring the hydrogen permeation rule of nonmetal in the thickness direction, and the device comprises a first supporting seat, a hydrogen filling tank, a sample, a hydrogen measuring hose, a hydrogen concentration detector, a second supporting seat, a hydrogen filling hole, a pressure relief hole, a detection hole, an exhaust window and a sealing O-shaped ring; hydrogen is charged through a hydrogen charging hole in one side of the hydrogen charging tank, the hydrogen permeates in the thickness direction of the sample according to the concentration gradient, and the hydrogen permeates into a detection hole and then enters a hydrogen concentration detector through a hydrogen measuring hose; the device can be used for measuring the hydrogen permeation rule of nonmetal in the thickness direction, and provides experimental support for related hydrogen permeation simulation, so that a basis is provided for research, development and selection of nonmetal materials of a hydrogen conveying system.

Description

Technical Field

[0001] The invention relates to a method and a device for measuring the hydrogen permeation law of a non-metal, and in particular to a method and a device for measuring the hydrogen permeation law of a non-metal along the thickness direction. Background Art

[0002] Hydrogen energy is one of the important development directions of new energy, an important way to reduce carbon emissions, and an important energy carrier for my country to achieve the goal of "carbon peak and carbon neutrality". In hydrogen energy storage and transportation technology, the use of existing natural gas pipelines in the form of hydrogen-blended natural gas can effectively reduce transportation costs. However, due to the gas permeability of non-metallic materials, hydrogen molecules will penetrate into non-metallic pipes in hydrogen environments, and their performance will be degraded by the influence of gas permeation coupling, posing risks to engineering applications. Therefore, the ability to measure the laws of non-metallic hydrogen permeation is of great significance to the research and development of non-metallic pipeline materials and the implementation of protection work.

[0003] In the study of hydrogen permeation laws in non-metals, finite element numerical simulation analysis technology is used to reveal the permeation path and concentration distribution law of hydrogen molecules inside non-metals. However, existing experimental methods and detection technologies cannot effectively and real-time detect the permeation path and concentration distribution law of hydrogen molecules along the thickness direction in non-metallic materials. The existing hydrogen permeation experiment can only measure the hydrogen concentration distribution on the surface of the sample.

[0004] In view of the above problems, the present invention aims to propose a method and device for measuring the hydrogen permeation law of non-metal along the thickness direction, to provide experimental support for related hydrogen permeation simulation and thus to provide a basis for the research and development and selection of non-metallic materials for hydrogen transport systems. Summary of the invention

[0005] In order to solve the problem that the permeation path and concentration distribution law of hydrogen molecules inside non-metal cannot be measured in the prior art, the present invention further provides a method and device for measuring the hydrogen permeation law of non-metal along the thickness direction.

[0006] The technical solution adopted by the present invention to solve the above problems is: it includes a first support base, a hydrogen filling tank, a sample, a hydrogen measuring hose, a hydrogen concentration detector, and a second support base; detection holes of the same depth are equidistantly distributed on the sample along the thickness direction, and the detection holes are staggered along the thickness direction, thereby reducing the change in the hydrogen permeation behavior of the material caused by the opening of the holes; the hydrogen concentration detector is connected to the sample through the hydrogen measuring hose, the hydrogen measuring hose and the detection hole are sealed by gas sealant, and a hydrogen detection tape is wrapped at the connection between the hydrogen measuring hose and the detection hole to avoid hydrogen concentration measurement errors caused by hydrogen leakage.

[0007] A hydrogen filling tank is welded on the first support seat, and the hydrogen filling tank is filled with an arc column. The arc chord is located below the intersection of the inner diameter of the hydrogen filling tank and the edge detection hole, which can ensure that the penetration area and path of each detection hole are consistent, and can also reduce the volume of the hydrogen filling tank. A small amount of hydrogen can reach a predetermined pressure; hydrogen filling holes and pressure relief holes are respectively provided on both sides of the hydrogen filling tank, and both the hydrogen filling holes and the pressure relief holes are tapered threaded holes. The hydrogen filling hole is connected to a straight-through air valve, and the pressure relief hole is connected to a three-way air valve with a pressure gauge; a sealing groove is also provided on the hydrogen filling tank for placing a sealing O-ring, and the connection between the sample and the hydrogen filling tank is sealed by a sealing O-ring.

[0008] The second support seat is provided with a circular exhaust window which is consistent with the inner diameter of the hydrogen filling tank, and the hydrogen that permeates the sample is discharged through the exhaust window, thereby avoiding the reverse penetration of high-concentration hydrogen formed by aggregation; the sample is located between the first support seat and the second support seat, and the first support seat and the second support seat are respectively provided with four corresponding threaded holes, and are connected by bolts, and strain gauges are affixed to the bolts, and the strain gauges are connected to the strain measuring instrument, and the force applied to the sealing O-ring is evenly distributed by controlling the force on the bolts, thereby achieving better sealing.

[0009] After assembling the device in the above manner, open the valves on the hydrogen filling hole and the pressure relief hole to introduce hydrogen and exhaust the air in the hydrogen filling tank to avoid the problem of inconsistent diffusion area and initial diffusion concentration caused by stratification of mixed gas. After exhausting, close the valve on the pressure relief hole and fill the hydrogen filling tank with hydrogen of a predetermined pressure. After the hydrogen penetrates into the detection hole, it enters the hydrogen concentration detector through the hydrogen measuring hose. By measuring the hydrogen concentration along the thickness direction at different times, the penetration path and concentration distribution law of hydrogen in the non-metallic material can be obtained. By measuring the change law of hydrogen concentration with time at the same thickness, the permeability coefficient, diffusion coefficient and solubility coefficient of hydrogen in the non-metallic material can also be calculated.

[0010] The beneficial effects of the present invention are:

[0011] 1. The present invention measures the hydrogen permeation law of non-metal along the thickness direction, realizes the non-metal hydrogen permeation test, and then analyzes the diffusion process of hydrogen molecules inside the non-metal and the distribution law of hydrogen concentration, providing experimental support for related hydrogen permeation simulation.

[0012] 2. The present invention measures the variation pattern of hydrogen concentration at the same thickness of non-metallic samples over time, calculates the permeability coefficient, diffusion coefficient and solubility coefficient of hydrogen in non-metallic materials, and provides a basis for the research, development and selection of non-metallic materials for hydrogen transport systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0014] Figure 1 This is a schematic diagram of the overall structure of a method and device for measuring hydrogen permeation law of a non-metal along the thickness direction in an embodiment of the present invention;

[0015] Figure 2 It is an exploded schematic diagram of the overall structure of a method and device for measuring hydrogen permeation law of non-metal along the thickness direction in an embodiment of the present invention;

[0016] Figure 3 The three-view diagram of a specimen and a schematic diagram of the specimen structure of a method and apparatus for measuring hydrogen permeation law of a non-metal along the thickness direction in an embodiment of the present invention;

[0017] Figure 4 This is a schematic diagram of the structure of a first support base of a method and device for measuring hydrogen permeation law of a non-metal along the thickness direction in an embodiment of the present invention;

[0018] Figure 5 This is a schematic diagram of the assembly of a first support base and a test piece of a method and device for measuring hydrogen permeation law of a non-metal along the thickness direction in an embodiment of the present invention;

[0019] Figure 6 Schematic diagram of the second support structure of a method and device for measuring hydrogen permeation law of non-metal along thickness direction in an embodiment of the present invention.

[0020] Figure numerals: It includes a first support base 1, a hydrogen filling tank 2, a sample 3, a hydrogen measuring hose 4, a hydrogen concentration detector 5, a second support base 6, a hydrogen filling hole 7, a pressure relief hole 8, a detection hole 9, an exhaust window 10, and a sealing O-ring 11. DETAILED DESCRIPTION

[0021] Next, the technical solution of the present invention will be described in detail and comprehensively based on the accompanying drawings provided by the embodiments of the present invention. It should be noted that the embodiments described herein are only a part of the many embodiments of the present invention, not the whole picture.

[0022] When describing the present invention, directional terms such as "center", "above", "below", "left", "right", "vertical", "horizontal", etc., which are defined with reference to the directions or positions shown in the drawings, are intended to help readers better understand the present invention and simplify the description, but do not mean that the devices or components mentioned must be constructed and operated in a specific direction. Therefore, these terms should not be regarded as limiting the scope of implementation of the present invention.

[0023] Specific implementation method 1: Combination Figure 1-Figure 6The present embodiment is described as a method and device for measuring hydrogen permeation law of non-metal along the thickness direction. A hydrogen filling tank 2 is welded on the first support seat 1, and a hydrogen filling hole 7 and a pressure relief hole 8 are respectively opened on both sides of the hydrogen filling tank 2; detection holes 9 are evenly distributed along the thickness direction on the sample 3; and a circular exhaust window 10 consistent with the inner diameter of the hydrogen filling tank 2 is opened on the second support seat 6.

[0024] Specific implementation method 2: Combination Figure 1 , Figure 3 The present embodiment is described, and the present embodiment describes a method and device for measuring the hydrogen permeation law of non-metal along the thickness direction. Adjacent detection holes 9 along the thickness direction and perpendicular to the thickness direction on the sample 3 are equidistantly staggered, and the distances are L and x respectively, so as to reduce the change of the hydrogen permeation behavior of the material caused by the opening; the hydrogen concentration detector 5 is connected to the sample 3 through the hydrogen measuring hose 4, and the hydrogen measuring hose 4 and the detection hole 9 are sealed by gas sealant, and a hydrogen detection tape is wrapped at the connection between the hydrogen measuring hose 4 and the detection hole 9 to avoid the hydrogen concentration measurement error caused by hydrogen leakage.

[0025] Specific implementation method three: Combination Figure 4 , Figure 5 This embodiment is described. This embodiment describes a method and device for measuring the hydrogen permeation law of non-metal along the thickness direction. A hydrogen filling tank 2 is welded on the first support seat 1. The hydrogen filling tank 2 is filled with an arc column. The arc chord is located below the intersection of the inner diameter of the hydrogen filling tank 2 and the edge detection hole 9. This can ensure that the permeation area of ​​each detection hole 9 is consistent with the path, and the volume of the hydrogen filling tank can be reduced. A small amount of hydrogen can reach a predetermined pressure; hydrogen filling holes 7 and pressure relief holes 8 are respectively opened on both sides of the hydrogen filling tank 2. The hydrogen filling holes 7 and the pressure relief holes 8 are both tapered threaded holes. The hydrogen filling hole 7 is connected to a straight-through air valve, and the pressure relief hole 8 is connected to a three-way air valve with a pressure gauge.

[0026] Specific implementation method four: Combination Figure 2 , Figure 4 , Figure 6 The present embodiment is described, and the present embodiment describes a method and device for measuring the hydrogen permeation law of non-metal along the thickness direction. A sealing groove is also provided on the hydrogen filling tank 2 for placing a sealing O-ring 11, and the connection between the sample 3 and the hydrogen filling tank 2 is sealed by the sealing O-ring 11; the sample 3 is located between the first support seat 1 and the second support seat 6, and the first support seat 1 and the second support seat 6 are each provided with four corresponding threaded holes, and are connected by bolts, and strain gauges are attached to the bolts, and the strain gauges are connected to the strain measuring instrument, and the force applied to the sealing O-ring 11 is evenly distributed by controlling the force on the bolts, so as to better seal.

[0027] Specific implementation method five: Combination Figure 6The present embodiment is described as a method and device for measuring hydrogen permeation law of non-metal along the thickness direction. A circular exhaust window 10 consistent with the inner diameter of the hydrogen filling tank 2 is provided on the second support seat 6, and the hydrogen permeated through the sample 3 is discharged through the exhaust window 10, thereby avoiding reverse permeation due to high concentration of hydrogen formed by aggregation.

[0028] The working principle is that the present invention measures the hydrogen concentration along the thickness direction at different times to obtain the permeation path and concentration distribution law of hydrogen in non-metallic materials to support related simulation research.

[0029] The present invention calculates the permeability coefficient, diffusion coefficient and solubility coefficient of non-metallic materials by measuring the change law of hydrogen concentration at the same thickness over time. The permeation behavior of gas molecules in non-metallic materials can be simply described as gas molecules being adsorbed or dissolved on the high-pressure side wall, permeating inside the non-metal according to the concentration gradient, and desorbing or evaporating on the other side wall. That is, the permeation process is decomposed into the dissolution process of gas molecules at the gas-solid interface and the diffusion process of hydrogen molecules inside the non-metallic material. The relationship between the three is expressed as:

[0030] P=DS (1)

[0031] Where: P is the permeability coefficient, which refers to the volume of gas that passes through a material of unit thickness per unit time and per unit area under unit pressure difference, and the unit is (m 3 ·m) / (m 2 ·s·Pa);

[0032] D is the diffusion coefficient, which represents the dynamic characteristics between gas molecules and materials, and the unit is m 2 / s;

[0033] S is the solubility coefficient, which represents the thermodynamic properties between gas molecules and materials, and the unit is m 3 / (m 3 ·Pa).

[0034] The hydrogen permeability coefficient is calculated by formula (2):

[0035]

[0036] Where: c is the measured gas mass concentration, in g / m 3 ;

[0037] V is the volume of the detection pore, in m 3 ;

[0038] ρ is the gas density, in g / m 3 ;

[0039] T0 and T are the temperature under standard conditions and the experimental temperature, respectively, in K;

[0040] d represents the material thickness, in m;

[0041] A is the permeable area, in m 2 ;

[0042] t is the experimental time, in seconds;

[0043] P1-P2 is the pressure difference between the two sides of the sample, in Pa.

[0044] The diffusion coefficient was calculated by the permeation lag time method:

[0045]

[0046] Where: t represents the penetration lag time, which is related to the material thickness and the unit is s.

[0047] Then the solubility coefficient of the material is calculated according to formula (1).

[0048] The test steps are as follows: Figure 1 After assembly, open the valves on the hydrogen filling hole 7 and the pressure relief hole 8 to pass hydrogen for 10 minutes to exhaust the air in the hydrogen filling tank 2 to avoid the problem of inconsistent diffusion area and initial diffusion concentration caused by mixed gas stratification. After exhausting, close the valve on the pressure relief hole 8 and fill the hydrogen filling tank 2 with hydrogen greater than 1atm. After the hydrogen penetrates into the detection hole 9, it enters the hydrogen concentration detector 5 through the hydrogen measuring hose 4. By measuring the hydrogen concentration along the thickness direction at different times, the permeation path and concentration distribution law of hydrogen in non-metallic materials can be obtained. By measuring the change law of hydrogen concentration over time at the same thickness, the permeability coefficient, diffusion coefficient and solubility coefficient of non-metallic materials can be calculated. Provide experimental support for related hydrogen permeation simulations and provide a basis for the research and development and selection of non-metallic materials for hydrogen delivery systems.

Claims

1. A method and device for measuring hydrogen permeation law of non-metal along thickness direction, characterized in that: The invention comprises a first support base (1), a hydrogen filling tank (2), a sample (3), a hydrogen measuring hose (4), a hydrogen concentration detector (5), and a second support base (6); the first support base (1) is welded with a hydrogen filling tank (2), and two sides of the hydrogen filling tank (2) are respectively provided with a hydrogen filling hole (7) and a pressure relief hole (8); the sample (3) is provided with detection holes (9) equidistantly distributed along the thickness direction; and the second support base (6) is provided with a circular exhaust window (10) having the same inner diameter as the hydrogen filling tank (2).

2. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claim 1, characterized in that: The test sample (3) is provided with detection holes (9) of the same depth which are evenly spaced along the thickness direction, and the detection holes (9) are staggered along the thickness direction.

3. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claims 1 and 2, characterized in that: The hydrogen concentration detector (5) is connected to the sample (3) through a hydrogen measuring hose (4), the hydrogen measuring hose (4) and the detection hole (9) are sealed by a gas sealant, and a hydrogen detection tape is wrapped around the connection between the hydrogen measuring hose (4) and the detection hole (9).

4. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claim 1, characterized in that: A hydrogen filling tank (2) is welded on the first support seat (1), and the hydrogen filling tank (2) is filled with an arc column, and the arc chord line is located below the intersection of the inner diameter of the hydrogen filling tank (2) and the edge detection hole (9).

5. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claims 1 and 4, characterized in that: A hydrogen filling hole (7) and a pressure relief hole (8) are respectively provided on both sides of the hydrogen filling tank (2). Both the hydrogen filling hole (7) and the pressure relief hole (8) are tapered threaded holes. The hydrogen filling hole (7) is connected to a straight-through air valve, and the pressure relief hole (8) is connected to a three-way air valve with a pressure gauge.

6. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claims 1 and 4, characterized in that: The hydrogen filling tank (2) is also provided with a sealing groove for accommodating a sealing O-ring (11), and the connection between the sample (3) and the hydrogen filling tank (2) is sealed by the sealing O-ring (11).

7. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claim 1, characterized in that: The sample (3) is located between the first support seat (1) and the second support seat (6). The first support seat (1) and the second support seat (6) are each provided with four corresponding threaded holes and are connected by bolts. The bolts are each provided with strain gauges, and the strain gauges are connected to the strain measuring instrument.

8. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claim 1, characterized in that: The second support seat (6) is provided with a circular exhaust window (10) having the same inner diameter as the hydrogen filling tank (2), and the hydrogen that permeates the sample (3) is discharged through the exhaust window (10).

9. A method and device for measuring hydrogen permeation law of non-metal along thickness direction according to claims 1-8, characterized in that: The test steps are as follows: after assembling the device, open the valves on the hydrogen filling hole (7) and the pressure relief hole (8) to pass hydrogen for 10 minutes, exhaust the air in the hydrogen filling tank (2), close the valve on the pressure relief hole (8) after exhausting, fill the hydrogen filling tank (2) with hydrogen at a predetermined pressure greater than 1atm, and detect the hydrogen concentration by a hydrogen concentration detector (5); by measuring the hydrogen concentration along the thickness direction at different times, the permeation path and concentration distribution law of hydrogen in the non-metallic material are obtained; by measuring the change law of hydrogen concentration at the same thickness with time, the permeability coefficient, diffusion coefficient and solubility coefficient of the non-metallic material are calculated, and the relationship between the three is expressed as follows: P=DS (1) Where: P is the permeability coefficient, unit is (m 3 ·m) / (m 2 ·s·Pa); D is the diffusion coefficient, in m 2 / s; S is the solubility coefficient, in m 3 / (m 3 ·Pa); The calculation formula of permeability coefficient P is: Where: c is the measured gas mass concentration, in g / m 3 ; V is the volume of the detection pore, in m 3 ; ρ is the gas density, in g / m 3 ; T0 and T are the temperature under standard conditions and the experimental temperature, respectively, in K; d represents the material thickness, in m; A is the permeable area, in m 2 ; t is the experimental time, in seconds; P1-P2 is the pressure difference between the two sides of the sample, in Pa; The diffusion coefficient was calculated by the permeation lag time method, and then the solubility coefficient of the material was calculated according to formula (1).

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