Low-temperature high-pressure hydrogen environment mechanical test bed

Abstract

The invention relates to the technical field of test devices, and provides a low-temperature high-pressure hydrogen environment mechanical test bench, which comprises a hydrogen environment device, a refrigeration device and a test device, and is characterized in that the hydrogen environment device comprises a hydrogen environment box and a hydrogen supply mechanism, and the hydrogen supply mechanism supplies hydrogen to the hydrogen environment box; the refrigerating device refrigerates the hydrogen environment box; the testing device comprises a testing clamp, a transmission rod and a driving mechanism, the transmission rod is arranged in the hydrogen environment box in a reciprocating sliding mode, the first end of the transmission rod extends into the hydrogen environment box, the second end of the transmission rod extends out of the hydrogen environment box, the testing clamp comprises a first clamping part and a second clamping part, and the first clamping part is fixed relative to the hydrogen environment box; the second clamping part is connected with the first end of the transmission rod. The driving mechanism drives the transmission rod to slide back and forth. Therefore, a low-temperature and high-pressure hydrogen environment can be provided in combination with the refrigeration device and the hydrogen supply mechanism, the to-be-tested material is mounted on the test fixture, and tension or pressure can be applied to the to-be-tested material by utilizing the driving mechanism, so that the mechanical property test of the to-be-tested material can be completed.

Description

Technical Field

[0001] The present invention relates to the technical field of testing devices, and in particular to a mechanical test bench for a cryogenic high-pressure hydrogen environment. Background Art

[0002] With the development of the hydrogen energy industry, on the premise of safety and controllability, the hydrogen energy industry actively promotes technological material process innovation and conducts exploration and practice of various storage and transportation methods. Among various storage and transportation methods, the cryogenic high-pressure storage and transportation method has attracted more and more attention due to its high hydrogen storage density.

[0003] In the cryogenic high-pressure storage and transportation method, the materials of hydrogen storage and transportation equipment are exposed to the harsh environment of cryogenic, high-pressure, and hydrogen-containing for a long time, and hydrogen-induced cracking or hydrogen corrosion may occur. This will cause irreversible damage to the hydrogen storage and transportation equipment, thereby affecting the operation of the entire hydrogen storage and transportation system. Therefore, it is very necessary to detect the mechanical properties of the materials of hydrogen storage and transportation equipment in a cryogenic high-pressure hydrogen environment.

[0004] Therefore, how to solve the problem of mechanical property testing of the materials of hydrogen storage and transportation equipment in a cryogenic high-pressure hydrogen environment has become an important technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] The present invention provides a mechanical test bench for a cryogenic high-pressure hydrogen environment, which is used to test the mechanical properties of the materials of hydrogen storage and transportation equipment in a cryogenic high-pressure hydrogen environment.

[0006] The present invention provides a mechanical test bench for a cryogenic high-pressure hydrogen environment, including: A hydrogen environment device, including a hydrogen environment box and a hydrogen supply mechanism. The interior of the hydrogen environment box has a sealed cavity, and the hydrogen supply mechanism is connected to the hydrogen environment box. The hydrogen supply mechanism is adapted to supply hydrogen to the hydrogen environment box; A refrigeration device, adapted to refrigerate the hydrogen environment box; A testing device, including a test fixture, a transmission rod, and a driving mechanism. The transmission rod is adapted to be reciprocally slidably disposed along its own axis in the hydrogen environment box. The first end of the transmission rod extends into the interior of the hydrogen environment box, and the second end of the transmission rod extends outside the hydrogen environment box. The test fixture is located inside the hydrogen environment box. The test fixture includes a first clamping portion and a second clamping portion that are cooperatively configured to clamp a material to be tested. The first clamping portion is relatively fixed to the hydrogen environment box, the second clamping portion is connected to the first end of the transmission rod, and the driving mechanism is in transmission connection with the second end of the transmission rod. The driving mechanism is adapted to drive the transmission rod to reciprocally slide relative to the hydrogen environment box.

[0007] According to a mechanical test bench for a cryogenic high-pressure hydrogen environment provided by the present invention, the test fixture further includes: A sleeve is sleeved outside the transmission rod. The transmission rod is in sliding fit with the sleeve. The second end of the sleeve is fixedly connected to the top end of the hydrogen environment chamber. A fixture seat body includes a first support and a second support that are relatively fixed and spaced apart along the axial direction of the transmission rod. The first clamping portion is fixedly connected to the first support. The second support is fixedly connected to the first end of the sleeve. The transmission rod penetrates through the second support, and the first end of the transmission rod is located between the first support and the second support.

[0008] A low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention further includes: A heat insulation cover is sleeved outside the cold head of the refrigeration device. At least part of the hydrogen environment chamber is located inside the heat insulation cover. The heat insulation cover is adapted to reduce the heat transfer between the cold head of the refrigeration device and the external environment and reduce the heat transfer between the hydrogen environment chamber and the external environment.

[0009] For a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the hydrogen environment chamber includes: A box body has an open top and is located inside the heat insulation cover. A cover body is arranged above the box body. The first end of the cover body extends into the heat insulation cover. The first end of the cover body is detachably connected to the box body. The second end of the cover body extends outside the heat insulation cover. The cover body is in sealing fit with the heat insulation cover, and a heat leakage prevention component is arranged inside the cover body.

[0010] For a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the cover body is a cylindrical structure with at least an open bottom end. The heat leakage prevention component includes: A first cold screen is arranged inside the cover body. There are multiple first cold screens. The plane where the first cold screens are located is perpendicular to the axis of the transmission rod. The multiple first cold screens are spaced apart along the axis of the transmission rod. The first cold screen is in a ring structure. The inner edge of the first cold screen is in contact with the outer side wall of the sleeve, and the outer edge of the first cold screen is in contact with the inner side wall of the cover body. A connecting rod. Each first cold screen is connected to the connecting rod. One end of the connecting rod is fixedly connected to the top end of the cover body.

[0011] For a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the cover body includes: A cylinder body has open ends at both ends. Flanges are arranged at both ends of the cylinder body. The flange at one end of the cylinder body is used for detachable connection with the box body. A transition flange plate is used for detachable connection with the flange at the other end of the cylinder body.

[0012] According to a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, an air inlet hole is provided on the cover body, the air inlet hole is connected to the hydrogen supply mechanism, and each of the first cold shields is provided with a ventilation hole.

[0013] According to a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the heat insulation cover includes: A second cold shield, the box body is located inside the second cold shield, the cover body penetrates through the top wall of the second cold shield, and the cold head of the refrigeration device penetrates through the bottom wall of the second cold shield; A vacuum cover, which is sleeved outside the second cold shield, the cover body penetrates through the top wall of the vacuum cover, and the refrigeration device penetrates through the bottom wall of the vacuum cover.

[0014] According to a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the second cold shield includes: A first main body part, which is in a cylindrical structure with an open top; A first sealing cover part, which is sleeved outside the cover body, and the first sealing cover part is suitable for sealing the open top of the first main body part; The vacuum cover includes: A second main body part, which is in a cylindrical structure with an open top; A second sealing cover part, which is sleeved outside the cover body, the second sealing cover part is in sealing cooperation with the cover body, the second sealing cover part is located on the side of the first sealing cover part away from the test fixture, the second sealing cover part is suitable for sealing the open top of the second main body part, and the second sealing cover part is detachably connected to the second main body part.

[0015] According to a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the first sealing cover part can reciprocally slide relative to the cover body along the axis direction of the transmission rod, and the heat insulation cover further includes: A spring pressing mechanism, which is arranged between the first sealing cover part and the second sealing cover part, and the spring pressing mechanism is suitable for making the first sealing cover part have a tendency to move away from the second sealing cover part.

[0016] According to a low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention, the refrigeration device includes: A refrigerator, which has a primary cold head and a secondary cold head, and the temperature of the secondary cold head is lower than the temperature of the primary cold head; A first mechanical thermal switch, which is suitable for controlling the thermal contact or thermal separation between the primary cold head and the hydrogen environment chamber; A second mechanical thermal switch, which is suitable for controlling the thermal contact or thermal separation between the secondary cold head and the hydrogen environment chamber.

[0017] The low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention includes a hydrogen environment device, a refrigeration device, and a testing device. The hydrogen environment device includes a hydrogen environment chamber and a hydrogen supply mechanism. The interior of the hydrogen environment chamber has a sealed cavity for providing a test environment for the material to be tested. The hydrogen supply mechanism is connected to the hydrogen environment chamber and is used to supply hydrogen to the hydrogen environment chamber. By controlling the hydrogen supply amount, the pressure inside the hydrogen environment chamber can be controlled. The refrigeration device is used to refrigerate the hydrogen environment chamber to reduce its temperature. Combining the hydrogen environment device and the refrigeration device can provide a low-temperature and high-pressure hydrogen environment for the material to be tested. The testing device includes a test fixture, a transmission rod, and a driving mechanism. The transmission rod is arranged in the hydrogen environment chamber and can reciprocally slide along its own axis direction. The first end of the transmission rod extends into the interior of the hydrogen environment chamber, and the second end of the transmission rod extends outside the hydrogen environment chamber. The test fixture is located inside the hydrogen environment chamber and includes a first clamping portion and a second clamping portion. The first clamping portion and the second clamping portion cooperate to clamp the material to be tested. The first clamping portion is relatively fixed to the hydrogen environment chamber, the second clamping portion is connected to the first end of the transmission rod, and the driving mechanism is drivingly connected to the second end of the transmission rod. The driving mechanism is used to drive the transmission rod to reciprocally slide relative to the hydrogen environment chamber. When the driving mechanism drives the transmission rod to slide relative to the hydrogen environment chamber, the transmission rod can drive the second clamping portion to approach or move away from the first clamping portion, thereby generating pressure or tension on the material to be tested. With such a setting, the material to be tested is installed on the test fixture, and the refrigeration device and the hydrogen supply mechanism are used to provide a low-temperature and high-pressure hydrogen environment for the material to be tested inside the hydrogen environment chamber. The driving mechanism can be used to make the test fixture apply tension or pressure to the material to be tested, thereby completing the mechanical property test of the material to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0019] Figure 1 is a cross-sectional view of the low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention Figure 1 .

[0020] Figure 2 is a cross-sectional view of the low-temperature and high-pressure hydrogen environment mechanical test bench provided by the present invention Figure 2 .

[0021] Figure 3 is a schematic structural diagram of the test fixture and the first cold screen provided by the present invention.

[0022] Reference Signs: 1. Transmission rod; 2. First clamping part; 3. Second clamping part; 4. Sleeve; 5. First support; 6. Second support; 7. Box body; 8. Cylinder body; 9. First cold shield; 10. Connecting rod; 11. Air inlet hole; 12. First main body part; 13. First cover part; 14. Second main body part; 15. Second cover part; 16. Spring pressing mechanism; 17. Refrigerator; 18. First-stage cold head; 19. Second-stage cold head; 20. First mechanical thermal switch; 21. Second mechanical thermal switch; 22. Support rod; 23. Connecting flange; 24. Adjusting rod; 25. Material to be tested; 26. Transition flange plate. Detailed implementation manners

[0023] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0024] The following Figures 1 to 3 describes the low-temperature and high-pressure hydrogen environment mechanical test bench of the present invention.

[0025] As Figures 1 to 3 shown, the low-temperature and high-pressure hydrogen environment mechanical test bench provided by the embodiment of the present invention includes a hydrogen environment device, a refrigeration device and a testing device.

[0026] Specifically, the hydrogen environment device includes a hydrogen environment box and a hydrogen supply mechanism. The interior of the hydrogen environment box has a sealed cavity for providing a test environment for the material 25 to be tested.

[0027] The hydrogen supply mechanism is connected to the hydrogen environment box. The hydrogen supply mechanism is used to supply hydrogen to the hydrogen environment box. By controlling the hydrogen supply amount, the pressure inside the hydrogen environment box can be controlled. The hydrogen supply mechanism includes a hydrogen cylinder. A pressure sensor is arranged inside the hydrogen environment box for detecting the pressure inside the hydrogen environment box.

[0028] It should be noted that the hydrogen environment box, as a high-pressure container under the action of internal high-pressure hydrogen, needs to meet the mechanical strength requirements.

[0029] The refrigeration device is used to refrigerate the hydrogen environment box to lower the temperature of the hydrogen environment box.

[0030] Combining the hydrogen environment device and the refrigeration device, a low-temperature and high-pressure hydrogen environment can be provided for the material 25 to be tested.

[0031] The test device includes a test fixture, a transmission rod 1, and a driving mechanism. The transmission rod 1 is disposed in the hydrogen environment chamber, and the transmission rod 1 can reciprocally slide along its own axis direction. The first end of the transmission rod 1 extends into the interior of the hydrogen environment chamber, and the second end of the transmission rod 1 extends outside the hydrogen environment chamber.

[0032] The test fixture is located inside the hydrogen environment chamber. The test fixture includes a first clamping portion 2 and a second clamping portion 3. The first clamping portion 2 and the second clamping portion 3 are cooperatively configured to clamp the material under test 25. The first clamping portion 2 is relatively fixed to the hydrogen environment chamber, the second clamping portion 3 is connected to the first end of the transmission rod 1, and the driving mechanism is in transmission connection with the second end of the transmission rod 1. The driving mechanism is configured to drive the transmission rod 1 to reciprocally slide relative to the hydrogen environment chamber.

[0033] When the driving mechanism drives the transmission rod 1 to slide relative to the hydrogen environment chamber, the transmission rod 1 can drive the second clamping portion 3 to approach or move away from the first clamping portion 2, thereby generating pressure or tension on the material under test 25.

[0034] With such a setting, the material under test 25 is installed on the test fixture, and a low-temperature, high-pressure hydrogen environment is provided for the material under test 25 in the hydrogen environment chamber by using a refrigeration device and a hydrogen supply mechanism. The driving mechanism can be used to apply tension or pressure to the material under test 25 by the test fixture, thereby completing the mechanical property test of the material under test 25.

[0035] It should be noted that for the structural principle of the driving mechanism, as long as the driving mechanism can drive the transmission rod 1 to reciprocally slide relative to the hydrogen environment chamber along the axis direction of the transmission rod 1, the specific structural form of the driving mechanism is not limited.

[0036] In an embodiment of the present invention, the test fixture further includes a sleeve 4 and a fixture seat body.

[0037] The sleeve 4 is sleeved outside the transmission rod 1. The second end of the sleeve 4 is fixedly connected to the top end of the hydrogen environment chamber. The transmission rod 1 is in sliding fit with the sleeve 4 so that the transmission rod 1 can slide relative to the hydrogen environment chamber.

[0038] It should be noted that in order to avoid hydrogen leakage, while enabling the transmission rod 1 and the sleeve 4 to slide relative to each other, it is necessary to ensure the sealing performance between the sleeve 4 and the transmission rod 1. The thickness of the sleeve 4 can be obtained by calculation according to the maximum load applied by the driving mechanism to meet the need for stable loading during the actual test of the low-temperature high-pressure hydrogen environment mechanical test bench.

[0039] The fixture seat body includes a first support 5 and a second support 6. The first support 5 and the second support 6 are relatively fixed, and the first support 5 and the second support 6 are spaced apart along the axis direction of the transmission rod 1. The space between the first support 5 and the second support 6 is used to install the first clamping portion 2 and the second clamping portion 3.

[0040] The second support 6 is fixedly connected to the first end of the sleeve 4. The transmission rod 1 passes through the second support 6, and the first end of the transmission rod 1 is located between the first support 5 and the second support 6. The first clamping portion 2 is fixedly connected to the first support 5, and the second clamping portion 3 is fixedly connected to the first end of the transmission rod 1.

[0041] Specifically, the first clamping portion 2 is threadedly connected to the first support 5, the second clamping portion 3 is threadedly connected to the first end of the transmission rod 1, and the second support 6 is threadedly connected to the first end of the sleeve 4.

[0042] For the relative fixation of the first support 5 and the second support 6, it can be realized by using the connecting support rods 22. A plurality of support rods 22 are arranged between the first support 5 and the second support 6, and the respective support rods 22 are spaced apart along the circumferential direction of the transmission shaft. Both ends of each support rod 22 are threadedly connected to the first support 5 and the second support 6 respectively.

[0043] The structures of the above-mentioned first clamping portion 2 and second clamping portion 3 can be designed according to the shape of the material 25 to be measured, as long as it is ensured that the first clamping portion 2 and the second clamping portion 3 can clamp the material 25 to be measured. In some embodiments, both ends of the material 25 to be measured are cylindrical. At this time, connection holes can be provided on the first clamping portion 2 and the second clamping portion 3, so that both ends of the material 25 to be measured are threadedly connected to the first clamping portion 2 and the second clamping portion 3.

[0044] In the embodiment of the present invention, the low-temperature high-pressure hydrogen environment mechanical test bench further includes a heat insulation cover.

[0045] For the cold head of the refrigeration device, it is required to be entirely located inside the heat insulation cover.

[0046] For the hydrogen environment chamber, at least a part of the hydrogen environment chamber is located inside the heat insulation cover. Specifically, the hydrogen environment chamber can be entirely located inside the heat insulation cover, or only a part of the hydrogen environment chamber can be located inside the heat insulation cover.

[0047] The heat insulation cover can reduce the heat transfer between the cold head of the refrigeration device and the external environment and reduce the heat transfer between the hydrogen environment chamber and the external environment, reducing heat leakage.

[0048] In this embodiment, the hydrogen environment chamber includes a box body 7 and a cover body.

[0049] The top end of the box body 7 is open, and the box body 7 is located inside the heat insulation cover. The cover body is arranged above the box body 7, and the transmission rod 1 passes through the cover body. The first end of the cover body extends into the heat insulation cover, and the first end of the cover body is detachably connected to the box body 7.

[0050] The second end of the cover body extends to the outside of the heat insulation cover. The cover body penetrates the top end of the heat insulation cover, and the cover body is in sealing cooperation with the heat insulation cover to maintain a vacuum environment, thereby reducing heat leakage.

[0051] A heat leakage prevention component is arranged inside the cover body, which can reduce the loss of cold quantity from the first end to the second end of the cover body and reduce heat leakage.

[0052] Flange structures are arranged at the top end of the box body 7 and the first end of the cover body, and the box body 7 and the cover body can be fixedly connected together by bolts. The material of the bolts can be selected as a material suitable for working in a low-temperature environment, which can be but is not limited to 316L stainless steel. To ensure the sealing performance of the connection position between the box body 7 and the cover body, a sealing structure can be arranged between the box body 7 and the cover body.

[0053] In this embodiment, the cover body is a cylindrical structure with at least an open bottom end, and there is a certain accommodation space inside the cover body.

[0054] The heat leakage prevention component includes a first cold screen 9 and a connecting rod 10.

[0055] The first cold screen 9 is arranged inside the cover body, and the plane where the first cold screen 9 is located is perpendicular to the axis of the transmission rod 1. There are multiple first cold screens 9, and the multiple first cold screens 9 are spaced apart along the axis direction of the transmission rod 1. Each first cold screen 9 is connected to the connecting rod 10, and one end of the connecting rod 10 is fixedly connected to the top end of the cover body, thereby connecting each first cold screen 9 to the cover body.

[0056] The first cold screen 9 is in a ring structure, the inner edge of the first cold screen 9 fits with the outer side wall of the sleeve 4, and the outer edge of the first cold screen 9 fits with the inner side wall of the cover body. The multiple first cold screens 9 can divide the internal space of the cover body into multiple spaces, and the first cold screen 9 can reduce the heat transfer between adjacent two spaces, thereby reducing the radiation loss of the cold quantity inside the box body 7 to the outside.

[0057] In this embodiment, an air inlet hole 11 is arranged on the cover body, and the air inlet hole 11 is connected to a hydrogen supply mechanism. Each first cold screen 9 is provided with a ventilation hole, and the hydrogen output by the hydrogen supply mechanism enters the second end of the cover body through the air inlet hole 11 and sequentially flows into the box body 7 through the ventilation holes on each first cold screen 9.

[0058] It should be noted that when arranging the ventilation holes on the first cold screen 9, it is necessary to ensure both the flow of hydrogen and its ability to block heat radiation. An air outlet hole is also arranged on the cover body for discharging and relieving pressure of the gas inside the hydrogen supply environment box.

[0059] In some embodiments, the cover body includes a cylinder 8 and a transition flange 26. Both ends of the cylinder 8 are open, and flanges are provided at both ends of the cylinder 8. The flange at one end of the cylinder 8 is used to connect to the box body 7, and the flange at the other end of the cylinder 8 is used to connect to the transition flange 26. The connection between the cylinder 8 and the transition flange 26 can be achieved by high-strength bolts, and the material of the high-strength bolts can be 35 chromium molybdenum steel (symbol: 35CrMo). To ensure the sealing between the cylinder 8 and the transition flange 26, a sealing structure can be provided between the transition flange 26 and the cylinder 8. The transmission rod 1 penetrates through the transition flange 26, and the transmission rod 1 is in sliding and sealing fit with the transition flange 26. The above intake hole 11 is provided on the transition flange 26, and the second end of the sleeve 4, the end of the connecting rod 10, and the hydrogen supply mechanism are all connected to the transition flange 26.

[0060] In the embodiments of the present invention, the heat shield includes a second cold screen and a vacuum cover. The box body 7 is located inside the second cold screen. The cover body penetrates through the top wall of the second cold screen, and the cold head of the refrigeration device penetrates through the bottom wall of the second cold screen.

[0061] The vacuum cover covers the outside of the second cold screen. The cover body penetrates through the top wall of the vacuum cover, and the refrigeration device penetrates through the bottom wall of the vacuum cover.

[0062] The vacuum cover can provide a vacuum environment for the hydrogen environment chamber and the second cold screen, reducing heat conduction and heat convection. The second cold screen is used to isolate the heat transfer between the hydrogen environment chamber and the vacuum cover, which can reduce radiative heat transfer. Combining the second cold screen and the vacuum cover can greatly reduce the heat leakage problem.

[0063] The vacuum cover can be made of stainless steel, and the second cold screen is made of copper. Multiple layers of insulating materials can also be wrapped outside the second cold screen to minimize the radiative heat leakage from the outside of the second cold screen to the inside as much as possible.

[0064] The low-temperature high-pressure hydrogen environment mechanical test bench in this embodiment further includes a vacuum pumping device and a nitrogen filling device. The vacuum pumping device can be used to evacuate the vacuum cover, the second cold screen, and the hydrogen environment chamber. When evacuating the hydrogen environment chamber, the nitrogen filling device can also be used to perform a nitrogen replacement operation on the hydrogen environment chamber to reduce the impurity gases in the hydrogen environment chamber. Specifically, the vacuum pumping device and the nitrogen filling device can be connected to the transition flange 26 of the hydrogen environment chamber.

[0065] In the embodiments of the present invention, the second cold screen includes a first main body portion 12 and a first cover portion 13.

[0066] The first main body portion 12 has a cylindrical structure with an open top end. The first cover portion 13 is sleeved outside the cover body of the hydrogen environment chamber. The first cover portion 13 can cover the open top end of the first main body portion 12.

[0067] The vacuum cover includes a second main body portion 14 and a second cover portion 15.

[0068] The second main body portion 14 is in the form of a cylindrical structure with an open top. The second cover portion 15 is sleeved outside the cover body of the hydrogen environment chamber, and the second cover portion 15 is in sealing cooperation with the cover body. The second cover portion 15 is located on the side of the first cover portion 13 away from the test fixture. The second cover portion 15 can cover the open top of the second main body portion 14, and the second cover portion 15 is detachably connected to the second main body portion 14. Specifically, the second cover portion 15 and the second main body portion 14 can be connected by bolts.

[0069] With such a setting, both the first cover portion 13 and the second cover portion 15 are arranged on the cover body of the hydrogen environment chamber, and both the first cover portion 13 and the second cover portion 15 can move along with the cover body of the hydrogen environment chamber. By making the distance between the first cover portion 13 and the second cover portion 15 match the distance between the open end of the first main body portion 12 and the open end of the second main body portion 14, while the second cover portion 15 covers the second main body portion 14, the first cover portion 13 also covers the first main body portion 12. The second cover portion 15 is detachably connected to the second main body portion 14. By removing the bolts connecting the second cover portion 15 and the second main body portion 14, the first cover portion 13 and the second cover portion 15 can move simultaneously along with the cover body of the hydrogen environment chamber to separately disengage from the first main body portion 12 and the second main body portion 14.

[0070] In a further embodiment, the first cover portion 13 is arranged in a structural form that can reciprocally slide along the axial direction of the transmission rod 1 relative to the cover body. At this time, the heat insulation cover further includes a spring pressing mechanism 16. The spring pressing mechanism 16 is arranged between the first cover portion 13 and the second cover portion 15, and the spring pressing mechanism 16 is used to make the first cover portion 13 tend to move away from the second cover portion 15.

[0071] After the second cover portion 15 is connected and cooperated with the second main body portion 14, under the action of the spring pressing mechanism 16, the first cover portion 13 tends to move away from the second cover portion 15, that is, the first cover portion 13 tends to approach the first main body portion 12, so that the first cover portion 13 is pressed against the first main body portion 12, which is beneficial to ensuring the thermal contact between the first cover portion 13 and the first main body portion 12.

[0072] It should be noted that both the first main body portion 12 and the second main body portion 14 can be arranged in a structural form in which a cylindrical structure with open ends at both ends is detachably connected to a bottom sealing plate. One end of the cylindrical structure and the bottom sealing plate are detachably connected by bolts. For the second main body portion 14, a sealing ring can be arranged between the cylindrical structure and the bottom sealing plate to ensure the sealing performance.

[0073] For the sealed fit between the second cover part 15 and the cover body, a connecting flange 23 can be provided on the cover body, and the connecting flange 23 is integrally formed with the cover body. The second cover part 15 has a through hole adapted to the connecting flange 23. The connecting flange 23 can be embedded in the through hole of the second cover part 15 and connected by bolts. A sealing ring is provided between the connecting flange 23 and the second cover part 15 to ensure the sealing performance between the second cover part 15 and the connecting flange 23.

[0074] A spring pressing mechanism 16 is arranged between the connecting flange 23 and the first cover part 13. The spring pressing mechanism 16 includes a plurality of spring components. The two ends of the spring components are respectively connected to the connecting flange 23 and the first cover part 13, and the plurality of spring components are distributed at intervals along the circumferential direction of the cover body. The spring component includes a compression spring.

[0075] A plurality of adjusting rods 24 are also arranged between the connecting flange 23 and the first cover part 13. The plurality of adjusting rods 24 are distributed at intervals along the circumferential direction of the cover body. One end of the adjusting rod 24 is connected to the connecting flange 23, and the other end of the adjusting rod 24 passes through the first cover part 13 and is threadedly connected to a nut. By screwing the nut, the distance between the connecting flange 23 and the first cover part 13 can be adjusted, and the adjusting rod 24 can guide the sliding of the first cover part 13 to ensure the stability of the first cover part 13. The nut can also prevent the first cover part 13 from slipping off the adjusting rod 24.

[0076] In the embodiment of the present invention, the refrigeration device includes a refrigerator 17, a first mechanical thermal switch 20 and a second mechanical thermal switch 21.

[0077] The refrigerator 17 has a first-stage cold head 18 and a second-stage cold head 19, and the temperature of the second-stage cold head 19 is lower than that of the first-stage cold head 18. The refrigerator 17 can be a GM refrigerator, which does not require cryogenic refrigerants, reducing the maintenance cost, and improving the long-term stability and service life of the system.

[0078] The GM refrigerator can achieve low temperature through multi-stage refrigeration. Generally, the first-stage cold head 18 can cool from room temperature to about 40K, and the second-stage cold head 19 is responsible for further cooling, from about 40K to the final target temperature, such as the critical temperature of high-pressure hydrogen.

[0079] The first-stage cold head 18 is connected to the second cold screen to provide cold for the second cold screen. The first-stage cold head 18 can also provide cold for the hydrogen environmental chamber. The first mechanical thermal switch 20 is used to control the thermal contact or thermal separation between the first-stage cold head 18 and the hydrogen environmental chamber, so as to control the cold supply of the first-stage cold head 18 to the hydrogen environmental chamber.

[0080] The secondary cold head 19 is used to provide cooling capacity to the hydrogen environmental chamber, and the second mechanical thermal switch 21 is used to control the thermal contact or thermal separation between the secondary cold head 19 and the hydrogen environmental chamber, thereby controlling the cooling capacity supply of the secondary cold head 19 to the hydrogen environmental chamber. Both the primary cold head 18 and the secondary cold head 19 can provide cooling capacity to the hydrogen environmental chamber, which can improve the refrigeration efficiency of the hydrogen environmental chamber and shorten the cooling time of the hydrogen environmental chamber.

[0081] The first mechanical thermal switch 20 and the second mechanical thermal switch 21 have the same structure, both including a control rod, a heat-conducting flange, and a heat-conducting member. The control rod is inserted into the vacuum cover and the second cold screen in a liftable manner, and the heat-conducting flange is arranged at the upper end of the control rod. The lifting of the control rod can make the heat-conducting flange contact or disengage from the hydrogen environmental chamber.

[0082] For the first mechanical thermal switch 20, the heat-conducting member is arranged between the heat-conducting flange and the primary cold head 18 of the refrigerator 17, and can transfer the cooling capacity of the primary cold head 18 to the heat-conducting flange, and then transfer the cooling capacity to the hydrogen environmental chamber when the heat-conducting flange contacts the hydrogen environmental chamber.

[0083] For the second mechanical thermal switch 21, the heat-conducting member is arranged between the heat-conducting flange and the secondary cold head 19 of the refrigerator 17, and can transfer the cooling capacity of the secondary cold head 19 to the heat-conducting flange, and then transfer the cooling capacity to the hydrogen environmental chamber when the heat-conducting flange contacts the hydrogen environmental chamber.

[0084] During the specific use process, according to the real-time temperature of the hydrogen environmental chamber, controlling the actions of the first mechanical thermal switch 20 and the second mechanical thermal switch 21 can control the temperature of the hydrogen environmental chamber within the target range.

[0085] When testing the mechanical properties of the material to be tested 25 using the low-temperature and high-pressure hydrogen environmental mechanical test bench provided by the embodiment of the present invention, disconnect the transition flange 26 from the cylinder body 8, apply a force to the transition flange 26 away from the cylinder body 8 to take out the transmission rod 1, the sleeve 4, the first cold screen 9, the connecting rod 10, and the test fixture from the box body 7 and the cylinder body 8. Select the first clamping part 2 and the second clamping part 3 with corresponding structural shapes according to the material to be tested 25, install the first clamping part 2 on the first support 5, install the second clamping part 3 on the transmission rod 1, and then install the material to be tested 25 on the first clamping part 2 and the second clamping part 3. Then place the transmission rod 1, the sleeve 4, the first cold screen 9, the connecting rod 10, and the test fixture into the box body 7 and the cylinder body 8, and connect the transition flange 26 with the cylinder body 8 together.

[0086] After ensuring excellent sealing of the low-temperature high-pressure hydrogen environmental mechanical test bench, use a vacuum pumping device to evacuate the vacuum chamber, the second cold shield, and the hydrogen environmental chamber, and perform nitrogen replacement and purification operations on the hydrogen environmental chamber through a nitrogen filling device. Start the refrigerator 17 so that the first-stage cold head 18 of the refrigerator 17 cools the second cold shield. At the same time, through the first mechanical thermal switch 20 and the second mechanical thermal switch 21, the first-stage cold head 18 and the second-stage cold head 19 of the refrigerator 17 cool the hydrogen environmental chamber simultaneously until the temperature inside the hydrogen environmental chamber stabilizes at a preset temperature.

[0087] Open the valve of the hydrogen cylinder so that high-pressure hydrogen enters the hydrogen environmental chamber through the gas pipeline. When the pressure detected by the pressure sensor inside the hydrogen environmental chamber reaches the specified value, close the pipeline valve to keep the pressure inside the hydrogen environmental chamber stable. Finally, open the pressure relief switch of the pipeline system to discharge the pressure in the pipeline.

[0088] Drive the transmission rod 1 to slide relative to the hydrogen environmental chamber through the drive mechanism under the set pressure, so as to apply continuous or intermittent tensile force to the material to be tested and conduct corresponding mechanical tests. The mechanical tests include but are not limited to slow tensile tests and fracture toughness tests.

[0089] After the test, drain the hydrogen inside the hydrogen environmental chamber and analyze the test results.

[0090] When it is necessary to replace the sealing material between the box body 7 and the cylinder body 8, the bolts at the connection position between the second cover part 15 and the second main body part 14 can be removed, and the hydrogen environmental chamber, the transmission rod 1, the first cover part 13, and the second cover part 15 can be taken out from the second main body part 14. Then, remove the bolts at the connection position between the cylinder body 8 and the box body 7 of the hydrogen environmental chamber. After replacing the sealing material, connect the box body 7 and the cylinder body 8 with bolts again. Check the sealing performance of the hydrogen environmental chamber. After confirming that the sealing of the hydrogen environmental chamber is qualified, place the hydrogen environmental chamber, the transmission rod 1, the first cover part 13, and the second cover part 15 on the second main body part 14. When the second cover part 15 contacts the second main body part 14, use bolts to tightly connect the second cover part 15 and the second main body part 14 together. At this time, the first cover part 13 also automatically makes thermal contact with the first main body part 12 under the action of the spring pressing mechanism 16.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-temperature and high-pressure hydrogen environment mechanical test bench, characterized in that, Comprising: A hydrogen environment device, including a hydrogen environment chamber and a hydrogen supply mechanism. The interior of the hydrogen environment chamber has a sealed cavity, and the hydrogen supply mechanism is connected to the hydrogen environment chamber. The hydrogen supply mechanism is adapted to supply hydrogen to the hydrogen environment chamber; A refrigeration device, adapted to refrigerate the hydrogen environment chamber; A testing device, including a test fixture, a transmission rod (1) and a driving mechanism. The transmission rod (1) is adapted to be reciprocally slidably arranged along its own axis direction in the hydrogen environment chamber. The first end of the transmission rod (1) extends into the interior of the hydrogen environment chamber, and the second end of the transmission rod (1) extends outside the hydrogen environment chamber. The test fixture is located inside the hydrogen environment chamber. The test fixture includes a first clamping portion (2) and a second clamping portion (3) that are cooperatively configured to clamp a material to be tested (25). The first clamping portion (2) is relatively fixed to the hydrogen environment chamber, and the second clamping portion (3) is connected to the first end of the transmission rod (1). The driving mechanism is in transmission connection with the second end of the transmission rod (1), and the driving mechanism is adapted to drive the transmission rod (1) to reciprocally slide relative to the hydrogen environment chamber.

2. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 1, characterized in that, The test fixture further includes: A sleeve (4), sleeved outside the transmission rod (1). The transmission rod (1) is in sliding fit with the sleeve (4), and the second end of the sleeve (4) is fixedly connected to the top end of the hydrogen environment chamber; A fixture seat body, including a first support (5) and a second support (6) that are relatively fixed and spaced apart along the axis direction of the transmission rod (1). The first clamping portion (2) is fixedly connected to the first support (5), and the second support (6) is fixedly connected to the first end of the sleeve (4). The transmission rod (1) penetrates through the second support (6), and the first end of the transmission rod (1) is located between the first support (5) and the second support (6).

3. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 2, wherein, Further comprising: A heat insulation cover, covering the outside of the cold head of the refrigeration device. At least part of the hydrogen environment chamber is located inside the heat insulation cover. The heat insulation cover is adapted to reduce the heat transfer between the cold head of the refrigeration device and the external environment and reduce the heat transfer between the hydrogen environment chamber and the external environment.

4. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 3, wherein The hydrogen environment chamber includes: A box body (7), with an open top. The box body (7) is located inside the heat insulation cover; A cover body, arranged above the box body (7). The first end of the cover body extends into the heat insulation cover. The first end of the cover body is detachably connected to the box body (7). The second end of the cover body extends outside the heat insulation cover. The cover body is in sealed cooperation with the heat insulation cover, and an anti-leakage heat component is arranged inside the cover body.

5. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 4, characterized in that, The cover body is a cylindrical structure with at least an open bottom. The anti-leakage heat component includes: The first cold screen (9) is arranged inside the cover body. There are multiple first cold screens (9). The plane where the first cold screen (9) is located is perpendicular to the axis of the transmission rod (1). The multiple first cold screens (9) are spaced apart along the axis direction of the transmission rod (1). The first cold screen (9) is in an annular structure. The inner edge of the first cold screen (9) fits against the outer side wall of the sleeve (4), and the outer edge of the first cold screen (9) fits against the inner side wall of the cover body; The connecting rod (10). Each of the first cold screens (9) is connected to the connecting rod (10). One end of the connecting rod (10) is fixedly connected to the top end of the cover body.

6. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 4, characterized in that The cover body includes: The cylinder body (8) with both ends open. There are flanges at both ends of the cylinder body (8). The flange at one end of the cylinder body (8) is used for detachable connection with the box body (7); The transition flange plate (26) is used for detachable connection with the flange at the other end of the cylinder body (8).

7. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 5, characterized in that, An air inlet hole (11) is arranged on the cover body. The air inlet hole (11) is connected to the hydrogen supply mechanism. Each of the first cold screens (9) is provided with a ventilation hole.

8. The cryogenic high-pressure hydrogen environment mechanical test bench according to claim 4, characterized in that The heat insulation cover includes: The second cold screen. The box body (7) is located inside the second cold screen. The cover body penetrates through the top wall of the second cold screen, and the cold head of the refrigeration device penetrates through the bottom wall of the second cold screen; The vacuum cover covers the outside of the second cold screen. The cover body penetrates through the top wall of the vacuum cover, and the refrigeration device penetrates through the bottom wall of the vacuum cover; The second cold screen includes: The first main body part (12) is in a cylindrical structure with an open top end; The first sealing cover part (13) is sleeved outside the cover body. The first sealing cover part (13) is suitable for sealing the open top end of the first main body part (12); The vacuum cover includes: The second main body part (14) is in a cylindrical structure with an open top end; The second sealing cover part (15) is sleeved outside the cover body. The second sealing cover part (15) is in sealing cooperation with the cover body. The second sealing cover part (15) is located on the side of the first sealing cover part (13) away from the test fixture. The second sealing cover part (15) is suitable for sealing the open top end of the second main body part (14). The second sealing cover part (15) is detachably connected to the second main body part (14).

9. The low-temperature and high-pressure hydrogen environment mechanical test bench according to claim 8, characterized in that, The first sealing cover part (13) can reciprocally slide relative to the cover body along the axis direction of the transmission rod (1). The heat insulation cover further includes: The spring pressing mechanism (16) is arranged between the first sealing cover part (13) and the second sealing cover part (15). The spring pressing mechanism (16) is suitable for making the first sealing cover part (13) have a tendency to move away from the second sealing cover part (15).

10. The low-temperature and high-pressure hydrogen environment mechanical test bench according to any one of claims 1-9, characterized in that, The refrigeration device includes: The refrigerator (17) has a primary cold head (18) and a secondary cold head (19). The temperature of the secondary cold head (19) is lower than the temperature of the primary cold head (18); The first mechanical thermal switch (20) is suitable for controlling the thermal contact or thermal separation between the primary cold head (18) and the hydrogen environment chamber; A second mechanical thermal switch (21) is adapted to control thermal contact or thermal separation between the secondary cold head (19) and the hydrogen environmental chamber.

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