Hydrogen coupon and use method thereof

Abstract

The invention provides a hydrogen hanging piece and a use method thereof. The hydrogen hanging piece comprises a TDS hanging piece and a slow stretching hanging piece, the TDS hanging piece and the slow stretching hanging piece are connected together through a connecting section; the size of the TDS hanging piece meets the testing requirement of TDS equipment, and the width of the connecting section is 1-2 mm. The hydrogen coupon is formed by combining the TDS coupon and the slow-stretching coupon, the connecting section of the hydrogen coupon is connected through the connecting section with the width not exceeding 2 mm, after soaking in liquid nitrogen, the material becomes brittle, the connecting section can be easily damaged, then the hydrogen coupon is divided into the independent TDS coupon and slow-stretching coupon, the size of the TDS coupon meets the testing requirement of TDS equipment, and the TDS coupon and the slow-stretching coupon can be separated from each other. Therefore, the separated TDS hanging piece and slow stretching hanging piece can be respectively subjected to TDS test and slow stretching test.

Description

Technical Field

[0001] The invention belongs to the field of hydrogen transportation and relates to a hydrogen hanging sheet and a use method thereof. Background Art

[0002] With the continuous maturity and improvement of hydrogen energy development and utilization technology, large-scale centralized hydrogen production and long-distance hydrogen transmission are the future trend. Pipeline transportation is the most economical way. Establishing a pure hydrogen high-pressure transportation pipeline network is the ultimate goal of building a hydrogen energy society. Affected by differences in gas properties, pipeline material characteristics, hydrogen blending ratio and external environment, hydrogen is prone to hydrogen embrittlement, penetration and leakage after entering the pipeline. Studies have shown that factors such as hydrogen pressure, purity, ambient temperature, pipeline strength level, deformation rate, microstructure, etc. will affect the degree of damage to the pipeline caused by hydrogen. Hydrogen embrittlement is the reduction of ductility of metal materials after absorbing hydrogen atoms. Hydrogen atoms are very small and can penetrate into solid metals. Once absorbed by metals, hydrogen will reduce the stress required for crack initiation and expansion in metals, resulting in embrittlement.

[0003] Therefore, it is necessary to provide a method for monitoring the safety of hydrogen transmission pipelines. Summary of the invention

[0004] In order to solve the above problems of the prior art, the present invention provides a hydrogen coupon and a method for using the same. The hydrogen coupon can be used to test hydrogen penetration and hydrogen-induced damage at the same time.

[0005] The present invention is achieved through the following technical solutions:

[0006] A hydrogen hanging sheet comprises a TDS hanging sheet and a slow stretch hanging sheet; the TDS hanging sheet and the slow stretch hanging sheet are connected together through a connecting section; the size of the TDS hanging sheet meets the test requirements of TDS equipment, and the width of the connecting section is 1-2mm.

[0007] Preferably, the size of the TDS coupon is in the range of 5-10 mm*10-20 mm.

[0008] Preferably, the thickness of the hydrogen hanging sheet is 1-3 mm.

[0009] Preferably, the slow-stretch hanging piece comprises a parallel section and clamping ends connected to both ends of the parallel section.

[0010] Furthermore, the TDS hanging sheet is connected to a clamping end of the slow-stretch hanging sheet through a connecting section.

[0011] Furthermore, the parallel section has a length of 20-60 mm and a width of 3-5 mm.

[0012] Furthermore, the length of the clamping end is 15-20 mm.

[0013] Preferably, the hydrogen hanging sheet is formed by machining.

[0014] Preferably, the material of the hydrogen hanging sheet is the same as that of the hydrogen transmission pipeline.

[0015] The method for using the hydrogen hanging sheet comprises:

[0016] Place the hydrogen coupon inside the hydrogen transmission pipeline;

[0017] The hydrogen coupon is taken out from the inside of the hydrogen transmission pipeline, placed in liquid nitrogen, the connecting section is broken, the TDS coupon is separated from the slow tensile coupon, the TDS coupon and the slow tensile coupon are taken out of the liquid nitrogen and subjected to TDS test and slow tensile test respectively.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The hydrogen hanging sheet of the present invention is a combination of a TDS hanging sheet and a slow stretch hanging sheet, and the connecting section is connected by a connecting section with a width of no more than 2 mm. After being soaked in liquid nitrogen, the material becomes brittle, and the connecting section can be easily destroyed, and then it is divided into an independent TDS hanging sheet and a slow stretch hanging sheet. The size of the TDS hanging sheet meets the test requirements of the TDS equipment, so the separated TDS hanging sheet and the slow stretch hanging sheet can be subjected to TDS test and slow stretch test respectively. The TDS test is used to detect the residence of hydrogen molecules in the hydrogen hanging sheet in the hydrogen transmission pipeline, and the slow stretch is used to detect whether the hanging sheet is damaged by hydrogen, resulting in a decrease in mechanical properties, so the present invention can simultaneously detect the penetration of hydrogen molecules in the material and the cracking of hydrogen-induced damage.

[0020] After being taken out from the hydrogen pipeline, the hydrogen coupon of the present invention is stored in a liquid nitrogen environment until it is sent to a laboratory for testing. The liquid nitrogen environment can slow down the activity of hydrogen, so that the hydrogen maintains its state inside the hydrogen pipeline; the liquid nitrogen lowers the temperature and makes the connecting section brittle, so that it can be easily divided into two independent coupons for testing respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the hydrogen hanging sheet of the present invention;

[0022] Figure 2 The test results of Example 1 are as follows;

[0023] Figure 3 The test results of Example 2 are as follows;

[0024] Figure 4 This is the test result of Example 3. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0026] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0027] In order to ensure the safety of hydrogen pipelines, the purpose of the present invention is to provide a hydrogen hanger, that is, a hanger placed inside the hydrogen pipeline, which is used to monitor the safety of the pipeline and whether it is damaged by hydrogen to reflect the health of the pipeline. The means of detecting whether the hydrogen hanger is damaged include TDS detection, slow rate stretching detection, four-point bending detection, etc. Among them, TDS is used to detect the residence of hydrogen molecules in the hydrogen pipeline of the hydrogen hanger, and slow rate stretching and four-point bending are used to detect whether the hanger is damaged by hydrogen, resulting in a decrease in mechanical properties.

[0028] In order to better monitor the reaction between hydrogen molecules and hydrogen coupons in the hydrogen pipeline, the best method is to take out the hydrogen coupons and test them immediately. However, due to the limitation of TDS equipment, the weight of the coupons for TDS testing is required to be less than 10g, and small-sized, low-weight coupons cannot be placed alone inside the hydrogen pipeline due to size limitations; large-sized coupons that can be placed inside the hydrogen pipeline cannot be machined to obtain small-sized coupons that can be used for TDS testing, because the heat release during the machining process will cause the hydrogen atoms originally inside the metal to overflow, thus losing the meaning of the test.

[0029] To this end, the present invention combines a small-sized coupon and a large-sized coupon to form a hydrogen coupon. The small-sized coupon can be used for TDS testing, and the large-sized coupon can be used for slow tensile testing.

[0030] refer to Figure 1The hydrogen hanging sheet of the present invention comprises a TDS hanging sheet 1 and a slow stretch hanging sheet 2; the TDS hanging sheet 1 and the slow stretch hanging sheet 2 are connected together by a connecting section 3, the size range of the TDS hanging sheet 1 is 5-10mm*10-20mm, and the mass of the TDS hanging sheet 1 is less than 10g.

[0031] There is no particular limitation on the length of the connecting section 3 connecting the slow-stretching hanging sheet 2 and the TDS hanging sheet 1. In a specific embodiment of the present invention, the width of the connecting section 3 is 1-2 mm.

[0032] In a specific embodiment of the present invention, the thickness of the integral hydrogen hanging sheet is 1-3 mm.

[0033] The important feature of the present invention is that the TDS hanging sheet and the slow stretch hanging sheet are combined, and the connecting section is connected by a connecting section with a width not exceeding 2 mm and a thickness not exceeding 3 mm. After being soaked in liquid nitrogen, the material becomes brittle and the connecting section can be easily broken and then divided into an independent TDS hanging sheet and a slow stretch hanging sheet. The TDS hanging sheet and the slow stretch hanging sheet can be used for TDS test and slow stretch test respectively.

[0034] The slow-stretch hanging plate 2 includes a parallel section 4 and a clamping end 5 connected to both ends of the parallel section, wherein the length of the parallel section 4 is 20-60 mm and the width is 3-5 mm; the length of the clamping end 5 of the slow-stretch hanging plate 2 is 15-20 mm. The TDS hanging plate 1 is connected to a clamping end 5 of the slow-stretch hanging plate 2 through a connecting section 3.

[0035] The hydrogen hanging sheet is made by mechanical processing, and the material used is the same as that of the hydrogen transmission pipeline, such as X40 or X52 steel grade material.

[0036] The method for using the hydrogen hanging sheet of the present invention comprises:

[0037] Place the hydrogen coupon inside the hydrogen transmission pipeline;

[0038] The hydrogen coupon is taken out from the inside of the hydrogen transmission pipeline and stored in liquid nitrogen. The connecting section is broken, and the TDS coupon is separated from the slow tensile coupon. After being transferred to the test site, the TDS coupon and the slow tensile coupon are taken out of the liquid nitrogen before the test to carry out the TDS test and the slow tensile test respectively.

[0039] Given the uniqueness of hydrogen, its molecules are small and can easily enter the interior of metal materials, and are also easy to overflow. The TDS test is to detect the extent to which hydrogen molecules enter the interior of the metal, so the hydrogen molecules are required to be inside the metal material. Due to the distance between the pipeline site and the laboratory, the TDS sample taken out cannot be guaranteed to be tested immediately, and if the hydrogen coupon is exposed to the air during the removal process, it will cause hydrogen overflow. Therefore, the hydrogen coupon in the present invention needs to be stored in a liquid nitrogen environment after being taken out from the hydrogen pipeline until it is sent to the laboratory for testing. The advantages of this method are: the activity of hydrogen can be slowed down in a liquid nitrogen environment, so that hydrogen maintains its state inside the hydrogen pipeline; liquid nitrogen lowers the temperature, which can make the connecting section brittle, and can easily be divided into two independent coupons for separate testing.

[0040] Implementation Case 1:

[0041] The material of the hydrogen pipeline is X52, and the hydrogen hanger is also made of X52 material. Its dimensions are as follows: the parallel section length of the above slow-stretch hanger is 25mm, the width is 4mm, and the clamping end length is 16mm. The size range of the TDS hanger is 5mm*11mm. The width of the connecting section is 1.4mm, and the thickness of the overall hydrogen hanger is 2.4mm.

[0042] The hydrogen coupon was placed in the hydrogen pipeline, taken out after 3 months, stored in liquid nitrogen, and transferred to the laboratory. The connection end was broken, and the slow stretch coupon was separated from the TDS coupon. The TDS coupon separated from the slow stretch coupon was tested for TDS. The results are as follows: Figure 2 shown.

[0043] Implementation Case 2:

[0044] The material of the hydrogen pipeline is X52, and the hydrogen hanger is also made of X52 material. Its dimensions are as follows: the parallel section length of the above slow-stretch hanger is 25mm, the width is 4mm, and the clamping end length is 16mm. The size range of the TDS hanger is 6mm*12mm. The width of the connecting section is 1.5mm, and the thickness of the overall hydrogen hanger is 2.5mm.

[0045] The hydrogen coupon was placed in the hydrogen pipeline, taken out after 4 months, stored in liquid nitrogen, and transferred to the laboratory. The connection end was broken, and the slow stretch coupon was separated from the TDS coupon. The TDS coupon separated from the slow stretch coupon was tested for TDS. The results are as follows: Figure 3 shown.

[0046] Implementation Case 3:

[0047] The material of the hydrogen pipeline is X52, and the hydrogen hanger is also made of X52 material. Its dimensions are as follows: the parallel section length of the above slow-stretch hanger is 20mm, the width is 4mm, and the clamping end length is 16mm. The size range of the TDS hanger is 3mm*10mm. The width of the connecting section is 1.0mm, and the thickness of the overall hydrogen hanger is 2.0mm.

[0048] The hydrogen coupon was placed in the hydrogen pipeline, taken out after half a year, stored in liquid nitrogen, and transferred to the laboratory. The connection end was broken, and the slow tensile coupon was separated from the TDS coupon. The slow tensile coupon separated from the TDS coupon was subjected to a slow tensile test. The results are as follows: Figure 4 shown.

[0049] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A hydrogen hanging sheet, characterized in that: The invention comprises a TDS hanging sheet (1) and a slow stretch hanging sheet (2); the TDS hanging sheet (1) and the slow stretch hanging sheet (2) are connected together via a connecting section (3); the size of the TDS hanging sheet (1) meets the test requirements of the TDS equipment, and the width of the connecting section (3) is 1-2 mm.

2. The hydrogen coupon according to claim 1, characterized in that: The size of the TDS hanging sheet (1) is in the range of 5-10 mm*10-20 mm.

3. The hydrogen coupon according to claim 1, characterized in that: The thickness of the hydrogen coupon is 1-3 mm.

4. The hydrogen coupon according to claim 1, characterized in that: The slow-stretch hanging piece (2) comprises a parallel section (4) and clamping ends (5) connected to both ends of the parallel section.

5. The hydrogen coupon according to claim 4, characterized in that: The TDS hanging sheet (1) is connected to a clamping end (5) of the slow-stretch hanging sheet (2) via a connecting section (3).

6. The hydrogen coupon according to claim 4, characterized in that: The parallel section (4) has a length of 20-60 mm and a width of 3-5 mm.

7. The hydrogen coupon according to claim 4, characterized in that: The length of the clamping end (5) is 15-20 mm.

8. The hydrogen coupon according to claim 1, characterized in that: The hydrogen hanging sheet is formed by mechanical processing.

9. The hydrogen coupon according to claim 1, characterized in that: The material of the hydrogen hanging sheet is the same as that of the hydrogen transmission pipeline.

10. The method for using the hydrogen coupon according to any one of claims 1 to 9, characterized in that: include: (1) Place the hydrogen coupon inside the hydrogen pipeline; (2) Take out the hydrogen coupon from the inside of the hydrogen pipeline, put it in liquid nitrogen, break the connecting section, separate the TDS coupon from the slow tensile coupon, take out the TDS coupon and the slow tensile coupon from the liquid nitrogen and perform TDS test and slow tensile test respectively.

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