Test method for balancing pressure and reducing friction in high-pressure hydrogen environment box

Abstract

The invention discloses a high-pressure hydrogen environment box and a test method for balancing pressure and reducing friction. The environment box comprises a test box body and a gas chamber, a sealing cavity is formed in the test box body; the air chamber is arranged on the test box body in a penetrating mode to form an upper air chamber and a lower air chamber, the upper air chamber and the lower air chamber are communicated with the internal sealing cavity, an upper piston rod is fixedly installed in the upper air chamber, and a lower piston rod is arranged in the lower air chamber in a sliding mode. The upper piston rod and the lower piston rod are respectively sealed with the upper air chamber and the lower air chamber through sealing structures, and the upper piston rod and the lower piston rod are used for mounting a test piece and an extensometer; the invention aims to solve the problems that when a high-pressure hydrogen environment fatigue device in the prior art carries out a fatigue test, an environment box and a piston rod are sealed only by using a sealing ring, so that air leakage is easily caused, and if multiple sealing rings are used, internal and external pressure difference is caused, so that friction force is increased, and test data are influenced.

Description

Technical Field

[0001] The present invention relates to the technical field of high-pressure hydrogen environment fatigue testing, and in particular to a test method for a high-pressure hydrogen environment box and balanced pressure to reduce friction. Background Art

[0002] The green hydrogen energy industry is booming, and the closely related hydrogen embrittlement problem needs to be overcome urgently. Hydrogen embrittlement refers to the phenomenon that hydrogen enters metal materials and interacts with the material's microstructure, causing serious degradation of the material's mechanical properties and causing brittle fracture during service. It has the characteristics of multi-scale, interdisciplinary, and wide coverage, and is a complex materials science problem. Relevant engineering scenarios include the damage of hydrogen pipelines and metal hydrogen storage tanks. Among the four major links of hydrogen energy production, storage, transportation, and use, storage and transportation are the bridge connecting the hydrogen production end and the application end, and are the key to the development of the hydrogen energy industry chain. The construction of pure hydrogen pipelines and the blending of hydrogen into natural gas pipelines are currently the safest methods of transporting hydrogen in my country, but hydrogen will accelerate crack growth. The problems of hydrogen embrittlement and hydrogen-assisted cracking cannot be ignored.

[0003] Currently, the maximum pressure for pure hydrogen pipelines is 6.3 MPa, while for hydrogen-blended pipelines, the maximum pressure reaches 12 MPa. Adding an environmental chamber to an existing fatigue testing machine can simulate actual operating conditions, but this inevitably raises the issue of sealing the extensometer and the upper and lower piston rods. Using only a sealing ring between the environmental chamber and the piston rod is prone to leakage. Using multiple sealing rings can lead to internal and external pressure differentials, increasing friction and affecting test data. Summary of the Invention

[0004] The present invention provides a test method for a high-pressure hydrogen environment box and balanced pressure to reduce friction. The purpose is to solve the problem in the prior art that when performing fatigue tests on high-pressure hydrogen environment fatigue devices and when performing gas environment mechanical tests, high pressure will cause the sealing ring to expand, generating huge friction with the upper and lower pull rods, thereby affecting the test data.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A high-pressure hydrogen environment chamber, comprising a test chamber body and an air chamber; the test chamber body has a sealed cavity therein; the air chamber is arranged through the test chamber body to form an upper air chamber and a lower air chamber, the upper air chamber and the lower air chamber being in communication with the sealed cavity therein; an upper piston rod is fixedly mounted within the upper air chamber, and a lower piston rod is slidably mounted within the lower air chamber; the upper piston rod and the lower piston rod respectively form a seal with the upper air chamber and the lower air chamber via a sealing structure; the upper piston rod and the lower piston rod are used to mount a test piece and an extensometer; The sealing structure includes a first sealing combination, a second sealing combination, and a third sealing combination provided on the air chamber and the upper piston rod and the lower piston rod. The first sealing combination, the second sealing combination, and the third sealing combination are used to seal the air chamber.

[0006] Furthermore, the test box body includes a kettle body and a kettle cover, the kettle body and the kettle cover are detachably sealed, and the air chamber is arranged through the kettle body.

[0007] Furthermore, the ends of the upper piston rod and the lower piston rod are both detachably provided with a clamp, the clamp is used to install the test piece, and the extensometer is used to be installed on the clamp.

[0008] Furthermore, an adapter is provided at the bottom of the kettle body, and the extensometer is used to be connected to a power source outside the kettle body through the adapter.

[0009] Furthermore, the kettle body is provided with an air inlet and an exhaust port. The air inlet is used to fill the sealed cavity with test gas, and the exhaust port is used to exhaust the test gas and perform vacuum treatment on the sealed cavity.

[0010] Furthermore, two retaining rings are provided on the upper piston rod and the lower piston rod, and a first sealing groove is provided on the retaining ring. The two retaining rings are connected to the lower piston rod to form a second sealing groove. The first sealing groove and the second sealing groove are both used to install a third sealing combination. The upper piston rod and the lower piston rod have the same structure.

[0011] Furthermore, a plurality of third sealing grooves are provided on the inner wall of the air chamber, and the interior of the third sealing grooves is used for installing the first sealing assembly and the second sealing assembly.

[0012] Furthermore, a safety valve is provided on the kettle body.

[0013] Furthermore, a guide belt is provided at the end of the air chamber, and the guide belt is used to install the first sealing assembly and the second sealing assembly in the third sealing groove.

[0014] The present invention also discloses a test method for balancing pressure and reducing friction, the specific steps of which are as follows: S1: Preparation and inspection of device components; S101: Make sure all components inside the test chamber are complete and intact; S2: assembly of specimen and fixture; S201: Connect the upper fixture to the upper piston rod through threads, and connect the lower fixture to the lower piston rod through threads, ensuring that the connection is firm and the coaxiality meets the requirements; S202: Place the test piece between the upper fixture and the lower fixture, and install the test piece on the upper fixture and the lower fixture to complete the sample fixation, ensure that the sample is installed stably, and the crack position matches the test requirements; S3: Static sealing structure construction; S301: Align the kettle cover with the installation position of the kettle body, insert ten evenly distributed stud bolts, put on hexagonal nuts, and pre-tighten the nuts to make the kettle cover fit the kettle body in preparation for subsequent sealing; S4: Dynamic sealing structure assembly S401: placing a first sealing assembly and a second sealing assembly in the first sealing groove and the second sealing groove at the front and rear ends of the upper piston rod and the lower piston rod, the gas chamber, and the kettle body respectively; S402: Installing a third sealing assembly in the third sealing grooves on the upper piston rod and the lower piston rod; S403: Apply lubricating oil to the first sealing groove, the second sealing groove, and the third sealing groove; S5: Confirmation and pre-commissioning of air pressure balance system; S501: Check the connection pipes and valves between the gas chamber and the kettle body to ensure there are no leaks or blockages; check the connection pipes between the gas chamber and the kettle body to ensure there are no leaks or blockages; simulate pre-pressurization to verify that the pressure transmission path between the gas chamber and the kettle body is smooth and the pressure balance function can be achieved normally. After the test, exhaust the gas and close the air inlet and exhaust ports; S6: The kettle cover is sealed and tightened; S601: Use a torque wrench to tighten the hexagonal nuts on the kettle cover in a uniform and symmetrical order, controlling the tightening torque to ensure the tightness of the static sealing structure. After completion, mark the nut position for subsequent inspection. S7: vacuuming the sealed chamber and detecting oxygen content; S701: Maintain the vacuum state inside the sealed chamber for 5-10 minutes to stabilize the environment inside the box; S702: Use a vacuum gauge to take readings, convert the readings into oxygen concentration in the sealed chamber, and determine whether it meets the test requirements. If not, continue vacuuming or check for leaks until the oxygen content reaches the standard, then stop vacuuming the sealed chamber. S8: Gas replacement and test gas filling; S801: Open the air inlet, flush in high-purity nitrogen, close the air inlet, and open the exhaust port again. Repeat this three times, then fill in the test gas. After reaching the test pressure, close the air inlet and exhaust ports to ensure the pressure in the environmental chamber and the purity of the test gas. S9: test operation and data collection; S901: drives the lower piston rod to move continuously in the air chamber; S902: Continuously record the readings on the extensometer; S10: End of test and reset of device; S1001: After the test reaches the set termination condition, the test equipment is turned off and data collection is stopped; the exhaust port is slowly vented to release the test gas in the environmental chamber, and the exhaust port is closed after the pressure in the chamber drops to normal pressure; S1002: Remove the hexagonal nuts and stud bolts from the kettle cover, open the kettle cover, take out the test piece and fixture, and clean the inside of the kettle body; check the condition of wearing parts such as the sealing ring and guide belt, and replace them in time if damaged. Return the device components to their original positions and prepare for the next test.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention mainly includes a test chamber body and an air chamber; in actual use, the staff installs the first sealing assembly and the second sealing assembly in the air chamber, and then installs the third sealing assembly on the upper piston rod and the lower piston rod, and then installs the upper piston rod and the lower piston rod in the air chamber and fixes the upper piston rod, and then installs the test piece between the upper piston rod and the lower piston rod, and then performs a vacuum operation in the sealed chamber to form a vacuum environment inside the sealed chamber, and then fills the sealed chamber with high-purity nitrogen, repeats the vacuuming and filling with high-purity nitrogen several times, so that the sealed chamber is filled with air, high-purity nitrogen and high-purity hydrogen, and then controls the lower piston rod to slide inside the air chamber, and the lower piston rod is pressed against the bottom of the sealed chamber. When the test piece is pushed, the test piece is pressurized and the readings of the extensometer are continuously recorded, thereby simulating the stress state of the test piece material under actual working conditions. The advantage of this setting is that, through the setting of the upper and lower air chambers with the same structure and the first, second and third sealing combinations, when conducting gas environment mechanics tests, the sealing ring will not expand due to high pressure, so that the material's hydrogen embrittlement resistance can be tested under high-pressure hydrogen corrosion conditions. Such a setting can reduce the friction between the lower piston rod and the air chamber, thereby making the test data more accurate. The structure of the test device is simple and reasonable, and it is ensured that the influence of the test results caused by the deformation of the sealing ring itself can be eliminated, thereby improving the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a side view of the present invention.

[0019] Figure 3 This is a structural diagram of embodiment 2 of the present invention.

[0020] In the figure, 101-sealed chamber, 102-upper air chamber, 103-lower air chamber, 104-upper piston rod, 105-lower piston rod, 106-extensometer, 107-first sealing combination, 108-second sealing combination, 109-third sealing combination, 110-kettle body, 111-kettle cover, 112-fixture, 113-test piece, 114-adapter, 115-air inlet, 116-exhaust port, 117-retaining ring, 118-first sealing groove, 119-second sealing groove, 120-third sealing groove, 121-safety valve, 122-guide belt. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the embodiments. The embodiments described are only some embodiments of the present invention and are not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] See also Figure 1-3 As shown, this embodiment discloses a high-pressure hydrogen environment box, including a test box body and an air chamber; the test box body has a sealed cavity 101 inside; the air chamber is arranged on the test box body to form an upper air chamber 102 and a lower air chamber 103, the upper air chamber 102 and the lower air chamber 103 are connected to the sealed cavity 101 inside, an upper piston rod 104 is fixedly installed inside the upper air chamber 102, and a lower piston rod 105 is slidably arranged inside the lower air chamber 103, the upper piston rod 104 and the lower piston rod 105 are respectively sealed with the upper air chamber 102 and the lower air chamber 103 through a sealing structure, and the upper piston rod 104 and the lower piston rod 105 are used to install a test piece 113 and an extensometer 106; The sealing structure includes a first sealing assembly 107 and a second sealing assembly 108 arranged on the air chamber, and a third sealing assembly 109 arranged on the upper piston rod 104 and the lower piston rod 105. The first sealing assembly 107, the second sealing assembly 108 and the third sealing assembly 109 are used to seal the air chamber.

[0023] The present invention mainly includes a test chamber body and an air chamber; in actual use, the staff installs the first sealing assembly 107 and the second sealing assembly 108 in the air chamber, and then installs the third sealing assembly 109 on the upper piston rod 104 and the lower piston rod 105, and then installs the upper piston rod 104 and the lower piston rod 105 in the air chamber and fixes the upper piston rod 104, and then installs the test piece 113 between the upper piston rod 104 and the lower piston rod 105, and then performs a vacuum operation in the sealed chamber 101 to form a vacuum environment inside the sealed chamber 101, and then fills the sealed chamber 101 with high-purity nitrogen, repeats the vacuuming and filling with high-purity nitrogen several times, so that the sealed chamber 101 is filled with air, high-purity nitrogen and high-purity hydrogen, and then controls the lower piston rod 10 5 slides inside the air cavity, and when pushed by the lower piston rod 105, the test piece 113 is pressurized, and the readings of the extensometer 106 are continuously recorded, thereby simulating the stress state of the test piece 113 material under actual working conditions. The advantage of this arrangement is that, through the arrangement of the upper and lower air chambers with identical structures and the first, second, and third sealing combinations, when conducting a gas environment mechanical test, the sealing ring will not expand due to high pressure, so that the material's hydrogen embrittlement resistance performance can be tested under high-pressure hydrogen corrosion conditions. This arrangement can reduce the friction between the lower piston rod 105 and the air chamber, thereby making the test data more accurate. The test device has a simple and reasonable structure and can ensure that the influence of the sealing ring's own deformation on the test results can be eliminated, thereby improving the accuracy of the test.

[0024] In some embodiments, the test chamber body includes a kettle body 110 and a kettle cover 111 . The kettle body 110 and the kettle cover 111 are detachably sealed and connected to each other, and an air chamber is provided through the kettle body 110 .

[0025] In actual use, an O-shaped groove is provided on the upper end surface of the kettle body 110, and an O-shaped sealing gasket is provided inside the O-shaped groove. When closing the kettle cover 111, the kettle cover 111 is aligned with the installation position of the kettle body 110, and ten evenly distributed stud bolts are inserted, and hexagonal nuts are put on. The nuts are pre-tightened to make the kettle cover 111 fit the kettle body 110. The O-shaped sealing gasket inside the O-shaped groove seals the kettle body 110 and the kettle cover 111, thereby improving the sealing performance inside the sealed cavity 101.

[0026] As an optional embodiment, in this embodiment, the first sealing combination 107, the second sealing combination 108 and the third sealing combination 109 all include several PTFE / NBR composite sealing rings. The several PTFE / NBR composite sealing rings in the first sealing combination 107 are arranged on the inner wall of the air chamber close to the outer wall of the kettle body 110, the several PTFE / NBR composite sealing rings in the second sealing combination 108 are arranged on the inner wall of the air chamber close to the inner wall of the kettle body 110, and the several PTFE / NBR composite sealing rings in the third sealing combination 109 are arranged on the upper piston rod 104 and the lower piston rod 105. When the lower piston rod 105 slides in the air chamber, the several PTFE / NBR composite sealing rings can balance the pressure so that the air pressure between the upper air chamber 102 and the lower air chamber 103 is the same.

[0027] In some embodiments, the ends of the upper piston rod 104 and the lower piston rod 105 are detachably provided with a clamp 112 . The clamp 112 is used to install the test piece 113 , and the extensometer 106 is used to be installed on the clamp 112 .

[0028] In actual use, the ends of the upper piston rod 104 and the lower piston rod 105 are threadedly connected to the clamp 112 installed above them, so as to facilitate the disassembly and assembly of the clamp 112.

[0029] In some embodiments, an adapter 114 is provided at the bottom of the kettle body 110, and the extensometer 106 is used to connect to the power supply outside the kettle body 110 through the adapter 114; the purpose of this setting is to facilitate the connection of the extensometer 106 with the external power supply while ensuring the sealing of the inside of the sealed cavity 101.

[0030] In some embodiments, the kettle body 110 is provided with an air inlet 115 and an exhaust port 116 . The air inlet 115 is used to fill the sealed cavity 101 with test gas, and the exhaust port 116 is used to exhaust the test gas and vacuum the sealed cavity 101 .

[0031] During actual use, both the air inlet 115 and the exhaust port 116 are provided with valves, and the staff can control the air inlet 115 to intake air or control the exhaust port 116 to exhaust air through the valves.

[0032] In some embodiments, two retaining rings 117 are provided on the upper piston rod 104 and the lower piston rod 105, and a first sealing groove 118 is provided on the retaining ring 117. After the two retaining rings 117 are connected to the lower piston rod 105, a second sealing groove 119 is formed. The first sealing groove 118 and the second sealing groove 119 are both used to install the third sealing assembly 109. The upper piston rod 104 and the lower piston rod 105 have the same structure.

[0033] During actual use, the plurality of PTFE / NBR composite sealing rings in the third sealing assembly 109 are installed in the first sealing groove 118 and the second sealing groove 119 respectively.

[0034] In some embodiments, a plurality of third sealing grooves 120 are provided on the inner wall of the air chamber, and the interior of the third sealing grooves 120 is used to install the first sealing assembly 107 and the second sealing assembly 108 .

[0035] During actual use, a number of third sealing grooves 120 are provided on the inner wall of the air chamber close to the outer wall and two positions of the inner wall of the kettle body 110. The third sealing grooves 120 are used to install a number of PTFE / NBR composite sealing rings, and triple sealing is achieved through the PTFE / NBR composite sealing rings on the upper piston rod 104 and the lower piston rod 105. Therefore, under the premise that the upper air chamber 102 and the lower air chamber 103 have the same structure, the pressure inside the air chamber and the sealed cavity 101 is balanced, which is more conducive to testing.

[0036] In some embodiments, a safety valve 121 is provided on the kettle body 110 .

[0037] In actual use, the purpose of setting the safety valve 121 is to prevent the air pressure inside the sealed chamber 101 from being too high. When the air pressure in the sealed chamber 101 is too high, the pressure can be released through the safety valve 121, so that the air pressure in the sealed chamber 101 is in a safe state.

[0038] In some embodiments, a guide strip 122 is provided at the end of the air chamber. The guide strip 122 is used to install the first sealing assembly 107 and the second sealing assembly 108 in the third sealing groove 120 .

[0039] As an optional implementation, in this embodiment, the guide belt 122 is a PTFE guide belt 122; providing the guide belt 122 can effectively prevent wear between the environmental box and the piston rod. The PTFE guide belt 122 has a low deformation rate and high anti-extrusion ability, ensuring low friction and high sealing performance.

[0040] As an optional implementation, in this embodiment, the test piece 113 is specifically a fatigue CT specimen with a horizontal crack; At the same time, in some different embodiments, the present invention also discloses a test method for balancing pressure and reducing friction, the specific steps of which are as follows: S1: Preparation and inspection of device components; S101: Make sure all components inside the test chamber are complete and intact; S2: Assembling the specimen and the fixture 112; S201: Connect the upper fixture 112 to the upper piston rod 104 through threads, and connect the lower fixture 112 to the lower piston rod 105 through threads, ensuring that the connection is firm and the coaxiality meets the requirements; S202: placing the fatigue CT specimen with a horizontal crack between the upper fixture 112 and the lower fixture 112, and installing the fatigue CT specimen with a horizontal crack on the upper fixture 112 and the lower fixture 112 to complete the specimen fixation, ensuring that the specimen is stably installed and the crack position matches the test requirements; S3: Static sealing structure construction; S301: Align the kettle cover 111 with the installation position of the kettle body 110, insert ten evenly distributed stud bolts, put on hexagonal nuts, and pre-tighten the nuts to make the kettle cover 111 fit the kettle body 110 in preparation for subsequent sealing; S4: Dynamic sealing structure assembly S401: Place the first sealing assembly 107 and the second sealing assembly 108 in the first sealing groove 118 and the second sealing groove 119 at the front and rear ends of the intersection of the upper piston rod 104 and the lower piston rod 105 with the air chamber and the kettle body 110; S402: Install a third sealing assembly 109 in the third sealing groove 120 on the upper piston rod 104 and the lower piston rod 105; S403: Apply lubricating oil to the first sealing groove 118, the second sealing groove 119, and the third sealing groove 120; S5: Confirmation and pre-commissioning of air pressure balance system; S501: Check the connection pipes and valves between the gas chamber and the kettle body 110 to ensure there are no leaks or blockages; check the connection pipes between the gas chamber and the kettle body 110 to ensure there are no leaks or blockages; simulate pre-pressurization to verify that the pressure transmission path between the gas chamber and the kettle body 110 is smooth and the pressure balance function can be achieved normally. After the test, exhaust the gas and close the air inlet 115 and the exhaust port 116; S6: The kettle cover 111 is sealed and tightened; S601: Use a torque wrench to tighten the hexagonal nuts on the kettle cover 111 in a uniform and symmetrical order, controlling the tightening torque to be consistent to ensure the tightness of the static sealing structure. After completion, mark the nut position for subsequent inspection. S7: vacuuming the sealed chamber 101 and detecting the oxygen content; S701: Maintain the vacuum state inside the sealed chamber 101 for 5-10 minutes to stabilize the environment inside the chamber; S702: Use a vacuum gauge to take a reading, convert the reading into the oxygen concentration in the sealed chamber 101, and determine whether it meets the test requirements. If not, continue vacuuming or check for leaks until the oxygen content meets the standard, and then stop vacuuming the sealed chamber 101. S8: Gas replacement and test gas filling; S801: Open the air inlet 115 and flush high-purity nitrogen gas into the chamber. Close the air inlet 115 and open the exhaust port 116 again. Repeat this three times and then fill the chamber with test gas. After reaching the test pressure, close the air inlet 115 and exhaust port 116 to ensure the pressure inside the chamber and the purity of the test gas. S9: test operation and data collection; S901: driving the lower piston rod 105 to continuously move in the air chamber; S902: The extensometer 106 measures the change in the crack size of the specimen through the signal transmission resistance and records the fatigue crack growth process; S10: End of test and reset of device; S1001: After the test reaches the set termination condition, the test equipment is turned off and data collection is stopped; the exhaust port 116 is slowly exhausted to release the test gas in the environmental chamber, and the exhaust port 116 is closed after the pressure in the chamber drops to normal pressure; S1002: Remove the hexagonal nuts and stud bolts from the kettle cover 111, open the kettle cover 111, take out the test piece 113 and the fixture 112, and clean the interior of the kettle body 110; check the status of wearing parts such as the sealing ring and the guide belt 122, and replace them in time if damaged. Return the device components to their original positions and prepare for the next test.

[0041] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "two ends", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one such feature.

[0043] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-pressure hydrogen environment box, characterized in that: include: A test box body, wherein the test box body has a sealed cavity inside; An air chamber is formed by penetrating the test chamber body to form an upper air chamber and a lower air chamber. The upper air chamber and the lower air chamber are connected to the internal sealed cavity. An upper piston rod is fixedly installed inside the upper air chamber, and a lower piston rod is slidably arranged inside the lower air chamber. The upper piston rod and the lower piston rod form a seal with the upper air chamber and the lower air chamber respectively through a sealing structure. The upper piston rod and the lower piston rod are used to install a test piece and an extensometer; The sealing structure includes a first sealing combination, a second sealing combination, and a third sealing combination provided on the air chamber and the upper piston rod and the lower piston rod. The first sealing combination, the second sealing combination, and the third sealing combination are used to seal the air chamber.

2. The high-pressure hydrogen environment box according to claim 1, characterized in that: The test box body comprises a kettle body and a kettle cover, the kettle body and the kettle cover are detachably sealed, and the air chamber is arranged through the kettle body.

3. The high-pressure hydrogen environment box according to claim 1, characterized in that: The ends of the upper piston rod and the lower piston rod are both detachably provided with a clamp, the clamp is used to install the test piece, and the extensometer is used to be installed on the clamp.

4. The high-pressure hydrogen environment box according to claim 2, characterized in that: An adapter is provided at the bottom of the kettle body, and the extensometer is used to be connected to a power source outside the kettle body through the adapter.

5. The high-pressure hydrogen environment box according to claim 2, characterized in that: The kettle body is provided with an air inlet and an exhaust port. The air inlet is used to fill the sealed cavity with test gas, and the exhaust port is used to exhaust the test gas and perform vacuum treatment on the sealed cavity.

6. The high-pressure hydrogen environment box according to claim 1, characterized in that: Two retaining rings are provided on the upper piston rod and the lower piston rod, and a first sealing groove is provided on the retaining ring. The two retaining rings are connected to the lower piston rod to form a second sealing groove. The first sealing groove and the second sealing groove are both used to install a third sealing combination. The upper piston rod and the lower piston rod have the same structure.

7. The high-pressure hydrogen environment box according to claim 2, characterized in that: A plurality of third sealing grooves are provided on the inner wall of the air chamber, and the interior of the third sealing grooves is used for installing the first sealing assembly and the second sealing assembly.

8. The high-pressure hydrogen environment box according to claim 2, characterized in that: A safety valve is provided on the kettle body.

9. The high-pressure hydrogen environment box according to claim 7, characterized in that: A guide belt is provided at the end of the air chamber, and the guide belt is used to install the first sealing assembly and the second sealing assembly in the third sealing groove.

10. A test method for balancing pressure and reducing friction, comprising using a high-pressure hydrogen environment box as claimed in claims 1 to 9, characterized in that: The specific steps are as follows: S1: Preparation and inspection of device components; S101: Make sure all components inside the test chamber are complete and intact; S2: assembly of specimen and fixture; S201: Connect the upper fixture to the upper piston rod through threads, and connect the lower fixture to the lower piston rod through threads, ensuring that the connection is firm and the coaxiality meets the requirements; S202: Place the test piece between the upper fixture and the lower fixture, and install the test piece on the upper fixture and the lower fixture to complete the sample fixation, ensure that the sample is installed stably, and the crack position matches the test requirements; S3: Static sealing structure construction; S301: Align the kettle cover with the installation position of the kettle body, insert ten evenly distributed stud bolts, put on hexagonal nuts, and pre-tighten the nuts to make the kettle cover fit the kettle body in preparation for subsequent sealing; S4: Dynamic sealing structure assembly S401: placing a first sealing assembly and a second sealing assembly in the first sealing groove and the second sealing groove at the front and rear ends of the upper piston rod and the lower piston rod, the gas chamber, and the kettle body respectively; S402: Installing a third sealing assembly in the third sealing grooves on the upper piston rod and the lower piston rod; S403: Apply lubricating oil to the first sealing groove, the second sealing groove, and the third sealing groove; S5: Confirmation and pre-commissioning of air pressure balance system; S501: Check the connection pipes and valves between the gas chamber and the kettle body to ensure there are no leaks or blockages; Check the connection pipes between the gas chamber and the kettle body to ensure there are no leaks or blockages; Simulate pre-pressurization to verify that the pressure conduction path between the gas chamber and the kettle body is smooth and the pressure balance function can be achieved normally. After the test, exhaust the gas and close the air inlet and exhaust ports; S6: The kettle cover is sealed and tightened; S601: Use a torque wrench to tighten the hexagonal nuts on the kettle cover in a uniform and symmetrical order, controlling the tightening torque to ensure the tightness of the static sealing structure. After completion, mark the nut position for subsequent inspection. S7: vacuuming the sealed chamber and detecting oxygen content; S701: Maintain the vacuum state inside the sealed chamber for 5-10 minutes to stabilize the environment inside the box; S702: Use a vacuum gauge to take readings, convert the readings into oxygen concentration in the sealed chamber, and determine whether it meets the test requirements. If not, continue vacuuming or check for leaks until the oxygen content reaches the standard, then stop vacuuming the sealed chamber. S8: Gas replacement and test gas filling; S801: Open the air inlet, flush in high-purity nitrogen, close the air inlet, and open the exhaust port again. Repeat this three times, then fill in the test gas. After reaching the test pressure, close the air inlet and exhaust ports to ensure the pressure in the environmental chamber and the purity of the test gas. S9: test operation and data collection; S901: drives the lower piston rod to move continuously in the air chamber; S902: Continuously record the readings on the extensometer; S10: End of test and reset of device; S1001: After the test reaches the set termination condition, the test equipment is turned off and data collection stops; Slowly exhaust the exhaust port to release the test gas in the environmental chamber, and close the exhaust port after the pressure in the chamber drops to normal pressure; S1002: Remove the hexagonal nuts and stud bolts from the kettle cover, open the kettle cover, take out the test piece and fixture, and clean the inside of the kettle body; check the condition of wearing parts such as the sealing ring and guide belt, and replace them in time if damaged. Return the device components to their original positions and prepare for the next test.

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