Thermal desorption gas chromatography analysis test system

Abstract

The invention provides a thermal desorption gas chromatography analysis test system, and relates to the technical field of hydrogen diffusion characteristic research of materials in a high-pressure hydrogen environment, and the thermal desorption gas chromatography analysis test system comprises a high-pressure permeation device and a thermal desorption diffusion device; the high-pressure permeation device comprises a hydrogen permeation upper end cover, a hydrogen permeation lower end cover and a sealing ring; a hydrogen permeation cavity is formed in the hydrogen permeation lower end cover, a hydrogen inlet channel is formed in the hydrogen permeation lower end cover, and the hydrogen permeation lower end cover is in threaded connection with the hydrogen permeation upper end cover; the sealing ring is arranged in an annular sealing groove between the hydrogen permeation upper end cover and the hydrogen permeation lower end cover; the thermal desorption diffusion device is used for the thermal desorption hydrogen release process of the sample; the hydrogen permeation upper end cover and the hydrogen permeation lower end cover are connected through the threads, so that a sample is convenient to disassemble, assemble, take and place, and meanwhile, the sealing performance of the hydrogen permeation cavity is improved; besides, by arranging an annular sealing groove and a sealing ring, the sealing performance of the high-pressure permeation device is further improved, and the problem of lack of equipment for testing the diffusion performance of hydrogen in the non-metallic material under the 100 MPa high-pressure environment is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of research on hydrogen diffusion characteristics of materials in a high-pressure hydrogen environment, and particularly to a thermal desorption gas chromatography analysis and testing system. Background Art

[0002] In the infrastructure field, high-pressure cylinders are currently recognized as the most effective means of hydrogen storage and are widely used. However, due to the extremely small molecular size of high-pressure hydrogen, it has strong permeability and can penetrate almost all materials. When hydrogen invades the interior of a metal, it will chemically react with the metal to form metal hydrides, which will have a negative impact on the mechanical properties of the metal and may even cause its damage or failure due to incorrect selection or design. When hydrogen penetrates into organic polymer materials such as rubber and plastics, it exists in the form of a diatomic gas and does not form any chemical bonds. However, this form of existence will have a potential impact on the morphological structure of the material. Especially in the case of rapid decompression, this phenomenon is called "rapid decompression failure", which may cause mechanical damage. Specifically, high-pressure hydrogen diffuses in the polymer, occupying the free space inside it and the previously existing cavities or voids. When the hydrogen pressure rapidly decreases, the hydrogen trapped in the cavities cannot escape from the free space or cavities inside the material in time, resulting in the material foaming or cracking, and thus permanent damage. In the hydrogen energy infrastructure, this phenomenon is particularly obvious in the damage to polymer components, such as the inner liner of type-IV hydrogen storage cylinders inside hydrogen fuel vehicles.

[0003] To gain a deeper understanding of this failure mode, more in-depth research is needed to develop a more reliable and robust polymer material system. In addition, measuring the transport properties of hydrogen in polymer materials, such as the diffusion coefficient, is crucial for this research. To more accurately evaluate this performance, developing a thermal desorption gas chromatography analysis and testing device for non-metallic materials to conduct hydrogen diffusion performance testing and evaluation of plastic inner liner materials has become a key technology for gas cylinder research and development. Summary of the Invention

[0004] The purpose of the present invention is to provide a thermal desorption gas chromatography analysis and testing system to solve the problems existing in the above-mentioned prior art. By setting a threaded connection hydrogen permeation upper end cover and a hydrogen permeation lower end cover, it is not only convenient for disassembly, installation, and sample taking and placing, but also improves the sealing performance of the hydrogen permeation cavity. In addition, by setting an annular sealing groove and a sealing ring, the present invention can further improve the sealing performance of the high-pressure permeation device, solving the problem of the lack of testing equipment for hydrogen diffusion performance in non-metallic materials under a 100 MPa high-pressure environment.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] A thermal desorption gas chromatography analysis and testing system includes a high-pressure permeation device and a thermal desorption and diffusion device; the high-pressure permeation device includes a hydrogen permeation upper end cap, a hydrogen permeation lower end cap and a sealing ring; the top of the hydrogen permeation lower end cap is provided with a hydrogen permeation cavity for placing a sample, the hydrogen permeation lower end cap is provided with a hydrogen intake channel communicated with the hydrogen permeation cavity, and the hydrogen permeation lower end cap is threadedly connected with the hydrogen permeation upper end cap; the sealing ring is arranged between the hydrogen permeation upper end cap and the hydrogen permeation lower end cap; the thermal desorption and diffusion device is used for the thermal desorption and hydrogen release process of the sample.

[0007] As an embodiment, the upper surface of the hydrogen permeation lower end cap is provided with an annular sealing groove located outside the hydrogen permeation cavity, the sealing ring is located in the annular sealing groove, and the hydrogen permeation upper end cap presses the sealing ring.

[0008] As an embodiment, the axial cross-sectional shape of the annular sealing groove is trapezoidal, and the upper top dimension of the trapezoidal shape is larger than the lower bottom dimension.

[0009] As an embodiment, the roughness of the inner upper surface of the hydrogen permeation upper end cap is not greater than 0.1 μm; the thread shear strength of the hydrogen permeation upper end cap and the hydrogen permeation lower end cap is not less than 400 MPa.

[0010] As an embodiment, the hydrogen intake channel is located at the bottom of the hydrogen permeation lower end cap, and the hydrogen intake channel is communicated with a high-pressure hydrogen pipeline through threads; a bracket is further connected to the hydrogen permeation lower end cap, and the brackets are distributed outside the hydrogen intake channel.

[0011] As an embodiment, the top of the hydrogen permeation upper end cap has a first screwing head in the shape of a hexagonal prism.

[0012] As an embodiment, the thermal desorption and diffusion device includes a thermal desorption upper end cap and a thermal desorption lower end cap. The thermal desorption upper end cap is provided with an exhaust channel for connecting a hydrogen collection and analysis mechanism; a thermal desorption cavity and an inert gas intake channel communicated with the thermal desorption cavity are arranged in the thermal desorption lower end cap. The inert gas intake channel is used for connecting an inert gas source, and the inert gas serves as a carrier gas for diffusing hydrogen; the thermal desorption lower end cap is threadedly and sealingly connected with the thermal desorption upper end cap.

[0013] As an embodiment, the bottom of the thermal desorption upper end cap is provided with a conical cavity with a gradually increasing diameter from top to bottom. The top of the conical cavity is coaxially communicated with the exhaust channel, the bottom of the conical cavity is coaxially communicated with the thermal desorption cavity, and the bottom diameter of the conical cavity is equal to the diameter of the thermal desorption cavity.

[0014] As an embodiment, external thread structures are provided at both the inert gas intake channel and the exhaust channel.

[0015] As an embodiment, the top end of the thermal desorption upper end cap has a second screwing head in the shape of a hexagonal prism.

[0016] The present invention has the following technical effects compared with the prior art:

[0017] 1. In the high-pressure permeation device of the present invention, by providing a threaded connection for the hydrogen permeation upper end cap and the hydrogen permeation lower end cap, it is not only convenient for disassembly and assembly and taking and placing samples, but also conducive to improving the sealing performance of the hydrogen permeation cavity; in addition, by providing an annular sealing groove and a sealing ring, the sealing performance of the high-pressure permeation device can be further improved.

[0018] 2. The high-pressure permeation device of the present invention solves the problem of the lack of testing equipment for the diffusion performance of hydrogen in non-metallic materials in a 100 MPa high-pressure environment, and promotes the development of research on the hydrogen permeation and diffusion performance of domestic plastic inner liner high-pressure hydrogen storage cylinder materials in a high-pressure hydrogen environment; in addition, the high-pressure permeation device can operate stably for a long time in a high-pressure environment, accurately control the voltage stabilization within 2%, demonstrating its excellent performance and reliability.

[0019] 3. The thermal desorption gas chromatography analysis and testing system of the present invention has excellent sealing performance, ensuring that hydrogen does not leak in the ultra-high-pressure environment and the atmospheric pressure environment of the high-pressure hydrogen permeation device and the thermal desorption diffusion device respectively, which is conducive to improving the accuracy of the thermal desorption analysis method, obtaining the hydrogen diffusion coefficient of the plastic inner liner material, and thus providing solid technical support for the development and selection of the inner liner material of the plastic inner liner high-pressure hydrogen storage cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is an exploded structural schematic diagram of the high-pressure permeation device in an embodiment of the present invention;

[0022] Figure 2 It is a longitudinal sectional view of the high-pressure permeation device in an embodiment of the present invention;

[0023] Figure 3 It is a structural schematic diagram of the hydrogen permeation lower end cap of the high-pressure permeation device in an embodiment of the present invention;

[0024] Figure 4 It is an assembled structural schematic diagram of the thermal desorption diffusion device in an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the explosion structure of the thermal desorption diffusion device in an embodiment of the present invention;

[0026] Figure 6 Longitudinal sectional view of the thermal desorption diffusion device in an embodiment of the present invention.

[0027] Description of the reference numerals in the drawings:

[0028] 1. Hydrogen permeation upper end cover; 11. First screwing head;

[0029] 2. Hydrogen permeation lower end cover; 21. Hydrogen permeation cavity; 22. Annular sealing groove; 23. Hydrogen intake channel;

[0030] 3. Sealing ring;

[0031] 4. Bracket; 41. Stud; 42. Nut;

[0032] 5. Thermal desorption upper end cover; 51. Exhaust channel; 52. Conical cavity; 53. Second screwing head;

[0033] 6. Thermal desorption lower end cover; 61. Inert gas intake channel; 62. Thermal desorption cavity;

[0034] 7. Specimen. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] The purpose of the present invention is to provide a thermal desorption gas chromatography analysis and testing system to solve the problems existing in the prior art. By setting the hydrogen permeation upper end cover and the hydrogen permeation lower end cover to be threadedly connected, it is not only convenient for disassembly and assembly and taking and placing specimens, but also improves the sealing performance of the hydrogen permeation cavity; in addition, by setting an annular sealing groove and a sealing ring, the present invention can further improve the sealing performance of the high-pressure permeation device, and solves the problem of the lack of testing equipment for the diffusion performance of hydrogen in non-metallic materials under a 100 MPa high-pressure environment.

[0037] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0038] As Figures 1 to 6As shown in the figure, this embodiment provides a thermal desorption gas chromatography analysis and testing system, including a high-pressure permeation device and a thermal desorption diffusion device; the high-pressure permeation device includes a hydrogen permeation upper end cover 1, a hydrogen permeation lower end cover 2, and a sealing ring 3. The top of the hydrogen permeation lower end cover 2 is provided with a hydrogen permeation cavity 21 for placing a sample 7. In this embodiment, the sample 7 can be selected as the plastic inner liner material of a high-pressure hydrogen storage cylinder. The longitudinal section of the hydrogen permeation cavity 21 can be T-shaped. The hydrogen permeation lower end cover 2 is provided with a hydrogen intake channel 23 communicating with the hydrogen permeation cavity 21. The hydrogen intake channel 23 can be arranged at the bottom of the hydrogen permeation lower end cover 2, and the channel where the hydrogen intake channel 23 communicates with the hydrogen permeation cavity 21 is coaxial with the hydrogen permeation cavity 21. The hydrogen permeation lower end cover 2 is threadedly connected to the hydrogen permeation upper end cover 1; the sealing ring 3 is arranged in the annular sealing groove 22 between the hydrogen permeation upper end cover 1 and the hydrogen permeation lower end cover 2 to ensure the sealing performance. The thermal desorption diffusion device is used for the thermal desorption and hydrogen release process of the sample 7.

[0039] In this embodiment, the high-pressure permeation device is provided with a threaded connection between the hydrogen permeation upper end cover 1 and the hydrogen permeation lower end cover 2, which is not only convenient for disassembly and assembly and taking and placing the sample 7, but also improves the sealing performance of the hydrogen permeation cavity 21; in addition, in this embodiment, by providing a sealing groove and a sealing ring 3, the sealing performance of the high-pressure permeation device can be further improved.

[0040] In this embodiment, the upper surface of the hydrogen permeation lower end cover 2 is provided with an annular sealing groove 22 located outside the hydrogen permeation cavity 21. The sealing ring 3 is located in the annular sealing groove 22, and the hydrogen permeation upper end cover 1 presses the sealing ring 3. In this embodiment, the axial cross-sectional shape of the annular sealing groove 22 is trapezoidal, and the upper top size of the trapezoidal shape is larger than the lower bottom size. The cross-sectional diameter of the sealing ring 3 is larger than the lower bottom size of the trapezoidal shape and smaller than the upper top size of the trapezoidal shape.

[0041] In this embodiment, the roughness of the inner upper surface of the hydrogen permeation upper end cover 1 is not greater than 0.1 μm to ensure the sealing performance of the hydrogen permeation chamber.

[0042] In this embodiment, the shear strength of the threads between the hydrogen permeation upper end cover 1 and the hydrogen permeation lower end cover 2 is not less than 400 MPa (able to withstand a shear strength of not less than 400 MPa), so that the connection strength between the hydrogen permeation upper end cover 1 and the hydrogen permeation lower end cover 2 is high, ensuring that the threads will not be deformed during the test and also avoiding leakage caused by the high-pressure damage of the threaded connection structure.

[0043] In this embodiment, the hydrogen intake channel 23 is located at the bottom of the hydrogen permeation lower end cover 2, and the hydrogen intake channel 23 is connected to the high-pressure hydrogen pipeline through threads. The hydrogen permeation lower end cover 2 is also connected with a bracket 4. The brackets 4 are distributed around the hydrogen intake channel 23 to provide sufficient working space and testing space for the connection of the high-pressure hydrogen pipeline. Specifically, the bracket 4 is a column, and the top of the column is provided with a stud 41. The hydrogen permeation lower end cover 2 is provided with a through hole, and the stud 41 passes through the through hole and is fixed by a nut 42.

[0044] In this embodiment, the top of the hydrogen permeation upper end cap 1 has a first screwing head 11 in the shape of a hexagonal prism, which facilitates screwing the hydrogen permeation upper end cap 1.

[0045] In this embodiment, the hydrogen permeation upper end cap 1, the hydrogen permeation lower end cap 2, and the bracket 4 are all made of austenitic stainless steel material, and the sealing ring 3 is made of fluororubber material.

[0046] The high-pressure permeation device in this embodiment solves the problem of the lack of testing equipment for the diffusion performance of hydrogen in non-metallic materials under a high-pressure environment of 100 MPa, and promotes the development of research on the hydrogen permeation and diffusion performance of domestic plastic-lined high-pressure hydrogen storage cylinder materials in a high-pressure hydrogen environment; in addition, the high-pressure permeation device can operate stably for a long time under a high-pressure environment, and accurately control the pressure stability within 2%, demonstrating its excellent performance and reliability.

[0047] In this embodiment, the thermal desorption diffusion device includes a thermal desorption upper end cap 5 and a thermal desorption lower end cap 6. An exhaust channel 51 for connecting a hydrogen collection and analysis mechanism is provided on the thermal desorption upper end cap 5; a thermal desorption cavity 62 and an inert gas inlet channel 61 communicating with the thermal desorption cavity 62 are provided in the thermal desorption lower end cap 6, and the inert gas inlet channel 61 is used to connect an inert gas source; the thermal desorption lower end cap 6 is threadedly connected to the thermal desorption upper end cap 5, and the seal is achieved by threads to prevent hydrogen leakage when the sample 7 is thermally desorbed. During operation, an inert gas is introduced into the thermal desorption cavity 62 to mix the hydrogen desorbed from the sample 7, and the mixed gas enters the hydrogen collection and analysis mechanism through the exhaust channel 51 to analyze the hydrogen concentration in the mixed gas.

[0048] In this embodiment, a conical cavity 52 with a gradually increasing diameter from top to bottom is provided at the bottom of the thermal desorption upper end cap 5. The top of the conical cavity 52 is coaxially connected to the exhaust channel 51, and the bottom of the conical cavity 52 is coaxially connected to the thermal desorption cavity 62, and the bottom diameter of the conical cavity 52 is equal to the diameter of the thermal desorption cavity 62. The conical cavity 52 is provided to facilitate the collection of hydrogen.

[0049] In this embodiment, external thread structures are provided at both the inert gas inlet channel 61 and the exhaust channel 51 to facilitate the connection of the inert gas source and the hydrogen collection and analysis mechanism.

[0050] In this embodiment, the top of the thermal desorption upper end cap 5 has a second screwing head 53 in the shape of a hexagonal prism, which facilitates screwing the thermal desorption upper end cap 5.

[0051] The thermal desorption gas chromatography analysis and testing system in this embodiment has excellent sealing performance, ensuring that hydrogen does not leak in the ultra-high pressure hydrogen permeation device and the thermal desorption diffusion device under ultra-high pressure environment and atmospheric pressure environment respectively, which is beneficial to improving the accuracy of the thermal desorption analysis method and obtaining the hydrogen diffusion coefficient of the plastic liner material, so as to provide solid technical support for the development and selection of the liner material of the plastic liner high-pressure hydrogen storage cylinder.

[0052] Adaptations made according to actual needs are within the protection scope of the present invention.

[0053] Specific examples are used in the present invention to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, there will be changes in the specific implementation manner and application scope according to the idea of the present invention. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A thermal desorption gas chromatography analysis and testing system, characterized in that, It includes a high-pressure permeation device and a thermal desorption diffusion device; the high-pressure permeation device includes: A hydrogen permeation upper end cover; A hydrogen permeation lower end cover, on the top of the hydrogen permeation lower end cover, there is a hydrogen permeation cavity for placing a specimen, on the hydrogen permeation lower end cover, there is a hydrogen intake channel communicating with the hydrogen permeation cavity, and the hydrogen permeation lower end cover is threadedly connected to the hydrogen permeation upper end cover; And a sealing ring, the sealing ring is arranged in the annular sealing groove between the hydrogen permeation upper end cover and the hydrogen permeation lower end cover; The thermal desorption diffusion device is used for the thermal desorption hydrogen release process of the specimen.

2. The thermal desorption gas chromatography analysis and testing system according to claim 1, wherein On the upper surface of the hydrogen permeation lower end cover, there is the annular sealing groove located outside the hydrogen permeation cavity, the sealing ring is located in the annular sealing groove, and the hydrogen permeation upper end cover presses the sealing ring.

3. The thermal desorption gas chromatography analysis and testing system according to claim 2, characterized in that, The axial cross-sectional shape of the annular sealing groove is trapezoidal, and the upper top size of the trapezoidal shape is larger than the lower bottom size.

4. The thermal desorption gas chromatography analysis and testing system according to claim 1, wherein The roughness of the inner upper surface of the hydrogen permeation upper end cover is not greater than 0.1μm; the shear strength of the thread between the hydrogen permeation upper end cover and the hydrogen permeation lower end cover is not less than 400MPa.

5. The thermal desorption gas chromatography analysis and testing system according to claim 1, characterized in that The hydrogen intake channel is located at the bottom of the hydrogen permeation lower end cover, and the hydrogen intake channel is connected to the high-pressure hydrogen pipeline through threads; on the hydrogen permeation lower end cover, there is also a bracket connected, and the brackets are distributed around the hydrogen intake channel.

6. The thermal desorption gas chromatography analysis and testing system according to claim 1, wherein The top of the hydrogen permeation upper end cover has a hexagonal prism-shaped first screwing head.

7. The thermal desorption gas chromatography analysis and testing system according to any one of claims 1 to 6, characterized in that, The thermal desorption diffusion device includes: A thermal desorption upper end cover, on the thermal desorption upper end cover, there is an exhaust channel for connecting a hydrogen collection and analysis mechanism; And a thermal desorption lower end cover, in the thermal desorption lower end cover, there is a thermal desorption cavity and an inert gas intake channel communicating with the thermal desorption cavity, the inert gas intake channel is used for connecting an inert gas source, and the inert gas is used as a carrier gas for diffusing hydrogen; the thermal desorption lower end cover is threadedly and hermetically connected to the thermal desorption upper end cover.

8. The thermal desorption gas chromatography analysis and testing system according to claim 7, characterized in that At the bottom of the thermal desorption upper end cover, there is a conical cavity with a diameter gradually increasing from top to bottom. The top of the conical cavity is coaxially connected to the exhaust channel, the bottom of the conical cavity is coaxially connected to the thermal desorption cavity, and the bottom diameter of the conical cavity is equal to the diameter of the thermal desorption cavity.

9. The thermal desorption gas chromatography analysis and testing system according to claim 7, characterized in that, External thread structures are provided at both the inert gas intake channel and the exhaust channel.

10. The thermal desorption gas chromatography analysis and testing system according to claim 7, characterized in that The top of the thermal desorption upper end cover has a hexagonal prism-shaped second screwing head.

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