Multifunctional detection device and method for hydrogen absorption and desorption process of metal hydride

Abstract

The invention provides a multifunctional detection device and method for a hydrogen absorption and desorption process of a metal hydride, the multifunctional detection device is used for hydrogen absorption and desorption performance test, internal expansion stress test and external strain test, the multifunctional detection device comprises a stress sensor arranged in a hydrogen storage tank, and the sensing end of the stress sensor is flush with the inner surface of the hydrogen storage tank; the strain gauge is arranged on the periphery of the straight cylinder body between the upper and lower flanges of the hydrogen storage tank; the mass flow meter is arranged in the hydrogen absorption and desorption pipeline; the electric signal acquisition card is electrically connected with the stress sensor and the mass flow meter; the strain gauge is electrically connected with the strain gauges; the device has the following beneficial effects: the device can simultaneously monitor the real stress change process in the tank and the strain change process outside the tank in the hydrogen absorption process and the hydrogen desorption process of the metal hydride in the hydrogen storage tank and test the hydrogen absorption and desorption performance; and an accurate and efficient evaluation method is provided for manufacturing, filling and using safety of the metal hydride hydrogen storage tank.

Description

Technical Field

[0001] The present invention relates to the technical field of safety evaluation of metal hydride hydrogen storage tanks, and in particular to a multifunctional detection device and method for the hydrogen absorption and desorption process of metal hydrides. Background Art

[0002] Solid-state hydrogen storage of metal hydrides has a high volumetric hydrogen storage density and is a hydrogen storage method with great development potential. However, metal hydrides will undergo pulverization and agglomeration during the process of hydrogen absorption / desorption. The metal hydride is accompanied by a significant volume expansion (15-25%) during the hydrogen absorption process. In the limited device space, the limited expansion rate will be converted into stress on the inner wall of the container. When the expansion stress exceeds the maximum value that the device can withstand, the device will deform or even explode. The volume expansion strain caused by agglomeration seriously affects the safe use of the container. Therefore, it is very necessary to study the size and development law of the volume expansion strain caused by metal hydrides to the container during the process of hydrogen absorption / desorption, and provide an accurate and efficient evaluation method for the production, filling and use safety of metal hydride hydrogen storage tanks. Summary of the invention

[0003] In view of the shortcomings of the prior art described above, an object of the present invention is to provide a multifunctional detection device and method for the hydrogen absorption and desorption process of metal hydrides, so as to solve the problem that the prior art cannot perform real-time detection of metal hydrides in the hydrogen absorption and desorption process, and cannot provide an accurate and efficient evaluation method for the manufacture, filling and use safety of metal hydride hydrogen storage tanks.

[0004] To achieve the above objectives and other related objectives, the present invention provides the following technical solutions:

[0005] A multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides comprises a hydrogen storage tank, wherein the hydrogen storage tank comprises a straight cylindrical tank body, an upper flange and a lower flange which are respectively mounted on the top and bottom ends of the straight cylindrical tank body and are integrally formed with the straight cylindrical tank body, an upper flange cover is mounted on the upper flange by fastening bolts, and a lower flange cover is also mounted on the lower flange by fastening bolts, a pressure sensor is threadedly connected at the center position of the top end of the upper flange cover, the sensing end of the pressure sensor passes through the top end of the upper flange cover and is flush with the bottom end of the upper flange cover, and a plurality of strain gauges distributed in the circumferential direction and located at the axial center position of the straight cylindrical tank body are provided on the circumferential surface of the straight cylindrical tank body.

[0006] In one embodiment of the present invention, sealing gaskets are provided between the upper flange cover and the upper flange and between the lower flange cover and the lower flange, a through hole connected to the straight cylindrical tank body is provided at the center position of the bottom end of the lower flange cover, and a filter element is provided at the top end of the lower flange cover to prevent hydrogen storage alloy powder from entering the pipeline through the through hole.

[0007] In one embodiment of the present invention, the pressure sensor is electrically connected to an electrical signal acquisition card via a wire, the electrical signal acquisition card is electrically connected to a computer via a wire, the electrical signal acquisition card is also electrically connected to a mass flow meter and a digital pressure gauge via a wire, the strain gauge is electrically connected to a strain gauge via a wire, and the strain gauge is also electrically connected to a computer via a wire.

[0008] In one embodiment of the present invention, it also includes a first pipeline, a second pipeline and a third pipeline connected to each other, and the first pipeline is provided with a sixth valve, a fifth valve and a seventh valve in sequence for controlling the on-off of the first pipeline, one end of the sixth valve is connected to the seventh valve through the fifth valve, the other end of the sixth valve is connected to the through hole on the lower flange cover, and the other end of the seventh valve is connected to the equipment to be filled with hydrogen.

[0009] In one embodiment of the present invention, a third valve and a first valve for controlling the on-off of the second pipeline are sequentially provided on the second pipeline, one end of the third valve is connected to the first valve, the other end of the third valve is respectively connected to the fifth valve and the sixth valve through a digital pressure gauge, and the other end of the first valve is connected to a high-pressure gaseous hydrogen storage tank.

[0010] In one embodiment of the present invention, a pressure reducing valve and a second valve, a fourth valve and an eighth valve for controlling the on and off of the third pipeline are sequentially provided on the third pipeline, one end of the pressure reducing valve is connected to the first valve and the third valve respectively, the other end of the pressure reducing valve is connected to the mass flow meter through the second valve, the mass flow meter is connected to a vacuum pump through the fourth valve and the eighth valve, and one end of the fourth valve and the eighth valve are also connected to the fifth valve and the seventh valve respectively.

[0011] A multifunctional detection method for the hydrogen absorption and desorption process of metal hydrides, based on the multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides, comprises: using hydrogen storage alloy powder in a hydrogen storage tank to absorb hydrogen and detect the hydrogen absorption process and using the hydrogen storage alloy powder in the hydrogen storage tank to desorb hydrogen and detect the desorption process; wherein, using the hydrogen storage alloy powder in the hydrogen storage tank to absorb hydrogen and detect the hydrogen absorption process comprises: firstly opening a first valve, a third valve and a sixth valve, and then continuously introducing high-purity hydrogen into the hydrogen storage tank at a constant hydrogen absorption pressure of 2MPa, so that the hydrogen storage alloy powder gradually begins to absorb hydrogen until the hydrogen absorption is completed; and simultaneously, during the hydrogen absorption process, a pressure sensor and a strain gauge perform real-time detection on the expansion stress of the hydrogen storage alloy powder in the hydrogen storage tank and the strain of the outer wall of the hydrogen storage tank until the hydrogen absorption is completed.

[0012] In one embodiment of the present invention, the use of hydrogen storage alloy powder in a hydrogen storage tank to release hydrogen and detect the hydrogen release process includes: starting a test program of a mass flow meter, first zeroing the mass flow meter, then adjusting the pressure of the pressure reducing valve to 0.8 MPa, and then opening the sixth valve, the third valve, the seventh valve, the fourth valve, and the second valve in sequence, and then starting hydrogen release; until the mass flow meter reading drops to 0 and remains unchanged for 10 minutes, the hydrogen release process is completed; at the same time, during the hydrogen release process, the pressure sensor and the strain gauge perform real-time detection of the expansion stress of the hydrogen storage alloy powder in the hydrogen storage tank and the strain of the outer wall of the hydrogen storage tank until the hydrogen release is completed.

[0013] In one embodiment of the present invention, before using the hydrogen storage alloy powder in the hydrogen storage tank to absorb and release hydrogen, it also includes: placing the hydrogen storage tank to be tested with the strain gauge pasted in a constant temperature water bath; then connecting the pressure sensor leads, the mass flow meter leads and the digital pressure gauge leads to the electrical signal acquisition card; then connecting the strain gauge leads to the strain gauge, turning on the strain gauge, and opening the pressure test program and strain test program installed on the computer, and clearing the strain data in the test program.

[0014] In one embodiment of the present invention, after the hydrogen storage alloy powder in the hydrogen storage tank is used to absorb and desorb hydrogen, it also includes: obtaining and recording the expansion stress value inside the hydrogen storage tank and the strain value of the outer wall of the hydrogen storage tank detected in real time by the pressure sensor and the strain gauge during the hydrogen absorption and desorption process, and then drawing a curve of the change of the expansion stress inside the hydrogen storage tank and the external strain of the hydrogen storage tank with the hydrogen absorption / desorption time, as well as a curve of the change of the hydrogen desorption amount with time based on the recorded data.

[0015] As described above, a multifunctional detection device and method for the hydrogen absorption and desorption process of a metal hydride of the present invention has the following beneficial effects: the pressure sensor in the present invention can detect the expansion stress of the hydrogen storage alloy powder in the hydrogen storage tank in the hydrogen absorption and desorption process in real time, and the strain gauge and strain meter can detect the strain of the outer wall of the hydrogen storage tank in the hydrogen absorption and desorption process in real time; therefore, the present invention can monitor the pressure field, gas flow rate, hydrogen absorption and desorption performance, expansion stress change in the tank and strain change of the outer wall of the tank during the hydrogen absorption and desorption process of the hydrogen storage tank, and has a variety of hydrogen absorption / desorption modes (constant current / constant pressure), accurate testing, simple operation, so that the various filling amounts of different hydrogen storage alloy powders can be targeted to perform anisotropic performance tests of the hydrogen absorption and desorption process, with high testing efficiency, and can realize the real-time and accurate monitoring of the stress and strain of the metal hydride hydrogen storage tank during the hydrogen absorption / desorption process, providing an accurate and efficient evaluation method for the production, filling and use safety of the metal hydride hydrogen storage tank, providing data support for the improvement of the metal hydride hydrogen storage system, and also providing reference significance for the future storage and transportation of hydrogen in a more effective way. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an overall structural diagram of a multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides disclosed in an embodiment of the present invention;

[0017] Figure 2 It is a front cross-sectional schematic diagram of a hydrogen storage tank in a multifunctional detection device for a metal hydride hydrogen absorption and desorption process disclosed in an embodiment of the present invention;

[0018] Figure 3 It is a front view schematic diagram of a pressure sensor in a multifunctional detection device for a metal hydride hydrogen absorption and desorption process disclosed in an embodiment of the present invention;

[0019] Figure 4 It is an overall flow chart of the multifunctional detection method of the metal hydride hydrogen absorption and desorption process disclosed in the embodiment of the present invention;

[0020] Figure 5 A curve diagram showing changes in internal expansion stress and internal gas pressure with hydrogen absorption / desorption time in a multifunctional detection method for a metal hydride hydrogen absorption / desorption process disclosed in an embodiment of the present invention;

[0021] Figure 6 It is a curve diagram showing the change of the outer wall circumferential strain and axial strain with the hydrogen absorption / desorption time in the multifunctional detection method for the hydrogen absorption and desorption process of metal hydrides disclosed in the embodiment of the present invention;

[0022] Figure 7 It is a curve diagram showing the variation of the hydrogen release amount and hydrogen release flow rate with the hydrogen release time in the constant current hydrogen release process in the multifunctional detection method for the metal hydride hydrogen absorption and desorption process disclosed in the embodiment of the present invention.

[0023] Component number description

[0024] 1. Hydrogen storage tank; 101. Straight tank body; 102. Upper flange; 103. Lower flange; 2. Hydrogen storage alloy powder; 3. Upper flange cover; 4. Lower flange cover; 5. Fastening bolts; 6. Sealing gasket; 7. Pressure sensor; 8. Strain gauge; 9. Through hole; 10. Filter element; 11. Thread; 12. Sensing end; 13. Electrical signal acquisition card; 14. Strain gauge; 15. Computer; 16. Mass flow meter; 17. Digital pressure gauge; 18. First pipeline; 19. Second pipeline; 20. Third pipeline; 21. Sixth valve; 22. Fifth valve; 23. Seventh valve; 24. Third valve; 25. First valve; 26. High-pressure gaseous hydrogen storage tank; 27. Pressure reducing valve; 28. Second valve; 29. ​​Fourth valve; 30. Eighth valve; 31. Vacuum pump. DETAILED DESCRIPTION

[0025] The following specific embodiments illustrate the implementation of the present invention, and those familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0026] The first embodiment of the present invention relates to a multifunctional detection device for the process of hydrogen absorption and desorption of metal hydrides, see Figures 1 to 3 The device is a metal hydride hydrogen absorption and desorption test device, and has the functions of detecting the internal expansion stress and the outer wall strain of the hydrogen storage tank 1, comprising a hydrogen storage tank 1, the hydrogen storage tank 1 comprising a straight cylinder tank body 101, an upper flange 102 and a lower flange 103 respectively mounted at the top and bottom ends of the straight cylinder tank body 101 and integrally formed with the straight cylinder tank body 101, an upper flange cover 3 is mounted on the upper flange 102 by fastening bolts 5, a lower flange cover 4 is also mounted on the lower flange 103 by fastening bolts 5, and sealing gaskets 6 are arranged between the upper flange cover 3 and the upper flange 102 and between the lower flange cover 4 and the lower flange 103;

[0027] Among them, the internal volume of the hydrogen storage tank 1 is 82.41ML, the filling rate of the AB2 type hydrogen storage alloy powder 2 is 50%, the hydrogen storage capacity is about 50L, the rated working pressure of the hydrogen storage tank 1 is 15MPa, and the material of the hydrogen storage tank 1 is 304 stainless steel. The test environment is a 25°C water environment and is placed vertically; the straight cylindrical tank body 101 of the hydrogen storage tank 1 is 45mm long, 65mm high, 40mm in inner diameter, and 48mm in outer diameter; the thickness of the upper and lower flange covers is 15mm, and the upper flange cover 3 and the lower flange cover 4 are each sealed with 8 M8 fastening bolts 5, the length of the fastening bolts 5 is 50mm, and the pitch is 0.8mm; a sealing gasket 6 made of O-type rubber material with a diameter of 55mm and a wire diameter of 4.5mm is also installed between the upper and lower flanges to achieve a better sealing effect.

[0028] A pressure sensor 7 is threadedly connected at the center position of the top of the upper flange cover 3. The sensing end 12 of the pressure sensor 7 passes through the top of the upper flange cover 3 and is flush with the bottom of the upper flange cover 3. The pressure sensor 7 is electrically connected to an electric signal acquisition card 13 through a wire. The electric signal acquisition card 13 is electrically connected to a computer 15 through a wire. The electric signal acquisition card 13 is also electrically connected to a mass flow meter 16 and a digital pressure gauge 17 through a wire. A plurality of strain gauges 8 distributed along the circumferential direction and located at the axial center position of the straight cylinder tank body 101 are provided on the circumferential surface of the straight cylinder tank body 101. The strain gauge 8 is electrically connected to a strain gauge 14 through a wire. The strain gauge 14 is also electrically connected to the computer 15 through a wire. A through hole 9 connected to the straight cylinder tank body 101 is provided at the center position of the bottom end of the lower flange cover 4. A filter element 10 for preventing the hydrogen storage alloy powder 2 from entering the pipeline through the through hole 9 is provided at the top of the lower flange cover 4.

[0029] In addition, a circle of M20×1.5 threaded holes is reserved on the upper flange cover 3 for installing the pressure sensor 7. The pressure sensor 7 is provided with an M18×1.5 thread 11. The sensing end 12 is a circular sensor sensing surface with a diameter of 16 mm. The thread 11 is connected to the threaded hole on the upper flange cover 3; the sensing end 12 of the pressure sensor 7 is flush with the inner wall of the upper flange cover 3; the strain gauge 14 is a stress strain tester; and in order to prevent the hydrogen storage alloy powder 2 from entering the hydrogen pipeline during vacuuming or hydrogen absorption and desorption, a stainless steel filter element 10 is installed at the hydrogen inlet at the through hole 9 of the hydrogen storage tank 1, and the pore size of the filter element 10 is 1-3 microns.

[0030] The utility model also includes a first pipeline 18, a second pipeline 19 and a third pipeline 20 which are connected to each other. A sixth valve 21, a fifth valve 22 and a seventh valve 23 for controlling the on-off of the first pipeline 18 are sequentially arranged on the first pipeline 18. One end of the sixth valve 21 is connected to the seventh valve 23 through the fifth valve 22, the other end of the sixth valve 21 is connected to the through hole 9 on the lower flange cover 4, and the other end of the seventh valve 23 is connected to the equipment to be filled with hydrogen; a third valve 24 and a first valve 25 for controlling the on-off of the second pipeline 19 are sequentially arranged on the second pipeline 19, one end of the third valve 24 is connected to the first valve 25, and the other end of the third valve 24 is connected to the first valve 25 through a digital pressure sensor. The force meter 17 is connected to the fifth valve 22 and the sixth valve 21 respectively, and the other end of the first valve 25 is connected to the high-pressure gaseous hydrogen storage tank 26; the third pipeline 20 is provided with a pressure reducing valve 27 and a second valve 28, a fourth valve 29 and an eighth valve 30 for controlling the on and off of the third pipeline 20 in sequence, one end of the pressure reducing valve 27 is connected to the first valve 25 and the third valve 24 respectively, the other end of the pressure reducing valve 27 is connected to the mass flow meter 16 through the second valve 28, the mass flow meter 16 is connected to the vacuum pump 31 through the fourth valve 29 and the eighth valve 30, and one end of the fourth valve 29 and the eighth valve 30 are also connected to the fifth valve 22 and the seventh valve 21 respectively.

[0031] The second embodiment of the present invention relates to a multifunctional detection method for the process of hydrogen absorption and desorption of metal hydride, wherein the expansion stress caused by the expansion of hydrogen storage alloy powder 2 during the process of hydrogen absorption and desorption of metal hydride is defined as: s =P t -P o , where P s is the expansion stress caused by the expansion of hydrogen storage alloy powder due to hydrogen absorption, P t is the stress value actually measured by the pressure sensor 7, P o is the hydrogen absorption pressure; the hoop stress of hydrogen storage tank 1 is defined as: Among them, σ θ is the hoop stress, P is the internal pressure, d i is the inner diameter of the tank, t is the wall thickness; the tank wall strain is defined as: Among them, ∈ is strain, σ θ is the hoop stress, E is Young's modulus, and the process is as follows Figure 4 As shown, the details are as follows:

[0032] S1, determining the installation position of the pressure sensor 7.

[0033] Specifically, the pressure sensor 7 is sealed at the top center of the upper flange cover 3 through an M20 thread 11, and the sensing end 12 is a circle with a diameter of 16 mm and a measuring range of 0-15 MPa. In order to make the detected stress more intuitively reflect the actual stress conditions inside the hydrogen storage tank 1, the sensing end 12 of the pressure sensor 7 does not penetrate into the interior of the hydrogen storage tank 1, but is just level with the top of the internal space of the hydrogen storage tank 1, so that the cylindrical space inside the hydrogen storage tank 1 remains intact. In addition, when the hydrogen storage alloy powder 2 absorbs hydrogen and expands in volume, due to the limited expansion space, the volume that should have expanded larger is converted into a certain amount of stress, which squeezes the inner wall of the hydrogen storage tank 1 and the sensing end 12 of the pressure sensor 7. Through this process, the pressure is converted by the pressure sensor 7 into an electrical signal and transmitted to the host computer 15.

[0034] S2, determining the sticking point of the strain gauge 8, and sticking the strain gauge 8.

[0035] Specifically, for the longitudinally placed hydrogen storage tank 1, a strain gauge 8 pasting point is selected at the center position along the axial center position of the straight cylinder section surface between the two flanges of the hydrogen storage tank 1, and the strain gauge 8 needs to be pasted in at least two directions, the circumferential direction and the axial direction, of the straight cylinder tank body 101; after the pasting point of the strain gauge 8 is selected, 800-grit sandpaper is used to grind the pasting point area, and the grinding direction is along the same direction as the axial direction of the straight cylinder tank body 101. After the grinding is completed, CC-33A strain gauge 8 bonding glue is used to bond the uniaxial strain gauge 8 along the axial direction of the hydrogen storage tank 1 and perpendicular to the axial direction of the hydrogen storage tank 1, that is, the tank body cylinder. The circumference of the body 101 is pasted at the center of the pasting point of the strain gauge 8; to ensure the accuracy of the test, the strain gauge 8 is pasted in no less than two groups, and after applying the CC-33A strain gauge 8 adhesive glue, it is left to stand in dry air for 24 hours to allow the glue to completely solidify; after the strain gauge 8 is pasted, a layer of 704 waterproof glue is applied on the outside of the strain gauge 8 to completely cover the strain gauge 8. The thickness of the waterproof glue is about 2-3mm. After applying the waterproof glue, it is left to stand in dry air for 24 hours to allow the waterproof glue to completely solidify, and the waterproof glue is applied to the surface of the strain gauge 8 to prevent water from penetrating and causing the strain gauge 8 to become damp and fail.

[0036] S3, leak detection is performed on the hydrogen storage tank 1, and the hydrogen storage tank 1 and the pipeline are evacuated.

[0037] Specifically, the hydrogen storage alloy powder 2 is added into the hydrogen storage tank 1, the hydrogen storage tank 1 is sealed by tightening the bolts 5, and the joints are checked for leaks by soapy water. If bubbles appear where the soapy water is applied, it indicates a leak and needs to be reinstalled. The leak is checked again until no leak occurs. After checking for leaks, the hydrogen storage tank 1 and the pipeline are evacuated by a vacuum pump 31 to remove air and impurities in the hydrogen storage tank 1 and the pipeline to speed up the hydrogen absorption process.

[0038] S4, carry out preparation work before hydrogen absorption.

[0039] Specifically, the pasted hydrogen storage tank 1 to be tested is placed in a constant temperature water bath at 25°C, which is similar to the application environment of the hydrogen storage tank 1; the leads of the pressure sensor 7, the leads of the mass flow meter 16 and the leads of the digital pressure gauge 17 are connected to the electrical signal acquisition card 13, and the pressure value and the flow value are converted into electrical signals through this process and transmitted to the host computer 15; then the leads of the strain gauge 8 are connected to the strain gauge 14, the strain gauge 14 is turned on, the strain test program is opened, and the strain data in the test program is cleared; wherein, the pressure signal is transmitted to the host computer software in the form of an electrical signal through the pressure sensor 7, which can intuitively reflect the change of expansion stress over time; the signal of the outer wall strain gauge 8 is transmitted to the host computer software in the form of an electrical signal through the strain gauge 14, which can intuitively reflect the change of the outer wall strain over time.

[0040] S5, using the hydrogen storage alloy powder 2 in the hydrogen storage tank 1 to absorb hydrogen.

[0041] Specifically, the purpose of alloy activation is to remove the oxide layer on the surface of the hydrogen storage alloy powder 2 so that the hydrogen storage alloy powder 2 can achieve the maximum hydrogen absorption capacity; first, the first valve 25, the third valve 24 and the sixth valve 21 are opened, and high-purity hydrogen is continuously introduced into the hydrogen storage tank 1 under a constant hydrogen absorption pressure of 2MPa, so that the hydrogen storage alloy powder 2 gradually begins to absorb hydrogen until the maximum hydrogen absorption capacity is reached, and the activation is completed, which also means that the hydrogen absorption is completed. The sign of the completion of hydrogen absorption in this test is that the expansion stress detection device detects that the alloy expansion stress in the reactor is no longer If the pressure drops below 0.1°, the hydrogen absorption stage is considered to be over; during the hydrogen absorption process, the expansion stress and outer wall strain of the hydrogen storage alloy powder 2 in the hydrogen storage tank 1 are detected in real time through the pressure sensor 7 and the strain gauge 14 until the hydrogen absorption is completed. The pressure is transmitted to the host computer software in the form of an electrical signal through the pressure sensor 7, which can intuitively reflect the change of the expansion stress over time; the outer wall strain signal is transmitted to the host computer software in the form of an electrical signal through the strain gauge 14, which can intuitively reflect the change of the outer wall strain over time; the mass flow meter 16 detects the real-time flow rate and total flow rate during the hydrogen release process.

[0042] S6, using the hydrogen storage alloy powder 2 in the hydrogen storage tank 1 to release hydrogen.

[0043] Specifically, the test program of the mass flow meter 16 is opened, the mass flow meter 16 is firstly zeroed, the pressure of the pressure reducing valve 24 is adjusted to 0.8MPa (because the pressure difference before and after the mass flow meter 16 cannot exceed 1MPa, otherwise the mass flow meter 16 will be damaged), the sixth valve 21, the third valve 24, the seventh valve 23, the fourth valve 29 and the second valve 28 are opened in sequence, and then the hydrogen release begins, until the indication of the mass flow meter 16 drops to 0 and remains unchanged within 10min, then the hydrogen release process ends; wherein, the flow collected by the mass flow meter 16 is transmitted to the upper computer software in the form of transmitting electrical signals through the electrical signal acquisition card 13, and in the hydrogen absorption and desorption process, the mass flow meter 16 can control the constant current hydrogen absorption of the hydrogen storage tank 1 during the hydrogen absorption process, and the mass flow meter 16 can control the constant current hydrogen release of the hydrogen storage tank 1 during the hydrogen release process, and the hydrogen absorption process can realize constant pressure hydrogen absorption through the pressure reducing valve 24 without passing through the mass flow meter 16; the hydrogen absorption and desorption amount can be recorded in real time and there are multiple hydrogen absorption and desorption modes to choose from.

[0044] S7, processes the recorded data and draws a curve based on the recorded data.

[0045] Specifically, according to the measured changes in the internal expansion stress value and the outer wall strain value during the hydrogen storage alloy powder 2 absorbing and desorbing hydrogen over time, and the changes in the real-time flow rate and the amount of hydrogen released over time, a curve is drawn, as shown in FIG. Figure 5 , Figure 6 , Figure 7 According to the recorded data, the curves of the internal expansion stress and external strain of the metal hydride hydrogen storage tank 1 changing with the hydrogen absorption / desorption time, and the curve of the hydrogen desorption amount changing with time are drawn.

[0046] More specifically, Figure 5 The curves of internal expansion stress and internal gas pressure changing with hydrogen absorption / desorption time;

[0047] Figure 5 -a is a curve showing the change of internal expansion stress and internal gas pressure with hydrogen absorption time; it can be seen from the figure that in the hydrogen absorption stage, at the initial stage of hydrogen absorption, the hydrogen storage alloy powder 2 absorbs hydrogen and expands, which will first occupy the remaining free space in the hydrogen storage tank 1, and the value of the pressure sensor 7 is the air pressure value of 2.0MPa, and there is no expansion stress on the pressure sensor 7; as the amount of hydrogen absorption continues to increase, the hydrogen storage alloy powder 2 further expands, the internal free space is filled, and obvious expansion stress is generated on the inner wall of the hydrogen storage tank 1, and as the hydrogen absorption process continues, the expansion stress will continue to increase, and when the hydrogen storage alloy powder 2 is saturated with hydrogen, the expansion stress will reach a stable value, and during this process, the internal gas pressure is maintained at a stable value of 2.0MPa;

[0048] Figure 5-b is the curve of the internal expansion stress and the internal gas pressure changing with the hydrogen decomposition time; it can be seen from the figure that in the hydrogen decomposition stage, the internal expansion stress will suddenly drop when the hydrogen decomposition process begins, which means that the elemental hydrogen in the hydrogen storage tank 1 and a part of the hydrogen absorbed by the hydrogen storage alloy powder 2 are quickly released, and the hydrogen storage alloy powder 2 also shrinks rapidly due to the hydrogen decomposition, and the expansion stress decreases rapidly. When the hydrogen is released to a certain level, the expansion stress will disappear, and the internal hydrogen pressure will also drop to close to one atmosphere.

[0049] Figure 6 The curves of the outer wall circumferential strain and axial strain changing with hydrogen absorption / desorption time;

[0050] Figure 6 -a is the curve of the change of the annular strain and axial strain of the outer wall with the hydrogen absorption time; it can be seen from the figure that before the reaction starts, the axial and radial strain values ​​are both 0; when 2.0MPa constant pressure hydrogen is introduced into the hydrogen storage tank 1, the strain value at each position suddenly rises. At the same time, the hydrogen is continuously and rapidly absorbed by the hydrogen storage alloy powder 2 and causes its volume expansion. This process releases a large amount of heat, causing the system temperature to rise sharply. Under the combined effect of the volume expansion of the hydrogen storage alloy powder 2, the hydrogen pressure and the reaction heat, the axial and radial strains quickly rise to the maximum value. As the hydrogen absorption process continues, the reaction rate gradually decreases, and the reaction heat gradually weakens. When the hydrogen absorption rate slowly decreases until the end of hydrogen absorption, the system temperature slowly returns to room temperature. It can be seen from the figure that the axial and radial shear strain values ​​also decrease and eventually stabilize.

[0051] Figure 6 -b is the curve of the change of the annular strain and axial strain of the outer wall with the dehydrogenation time; it can be seen from the figure that when the dehydrogenation step starts, the dehydrogenation flow rate is set to 2L / min, and the hydrogen absorbed by the alloy powder is gradually released. This process absorbs a large amount of heat and gradually reduces the system temperature. Due to the gradual decrease in the system temperature, the strain values ​​at various positions also gradually decrease. As the dehydrogenation process continues, the dehydrogenation rate and thermal effect also gradually decrease. At the end of the dehydrogenation, the system temperature slowly returns to room temperature, and the strain value also increases and returns to the initial value of 0.

[0052] Figure 7 This is a curve of the change of hydrogen release amount and hydrogen release flow rate with hydrogen release time in the constant current hydrogen release process; it can be seen from the figure that when the hydrogen release step starts, the hydrogen release flow rate is set to 2L / min. After the flow rate is maintained at 2L / min for a period of time, when the hydrogen release amount is not enough to maintain the set value, the flow rate will drop rapidly, and then slowly drop until it drops to 0. The total amount of hydrogen released gradually increases with the hydrogen release time until the hydrogen release ends.

[0053] In summary, the tested AB2 type hydrogen storage alloy powder 2 can maintain 13.8 minutes when releasing hydrogen at 2L / min when the filling volume is 50% and the hydrogen is saturated, and it takes 77.8 minutes to release all the hydrogen; the design working pressure of the hydrogen storage tank 1 is 15MPa, and the maximum strain that the tank wall can withstand is 375μ∈. The maximum expansion stress generated by the hydrogen storage alloy powder 2 on the inner wall of the hydrogen storage tank 1 after hydrogen absorption and expansion is 5.10MPa, the maximum external axial strain value is 47μ∈, and the maximum radial strain value is 201μ∈. Therefore, the internal expansion stress value and outer wall strain value generated by the metal hydride in the process of hydrogen absorption and desorption meet the design safety requirements.

[0054] In summary, the pressure sensor 7 in the present invention can sense the expansion stress of the hydrogen storage alloy powder 2 in the hydrogen storage tank 1 during the hydrogen absorption and desorption process, and the strain gauge 8 and the strain gauge 14 can detect the strain of the outer wall of the hydrogen storage tank 1 during the hydrogen absorption and desorption process in real time; therefore, the present invention can monitor the pressure field, gas flow rate, hydrogen absorption and desorption performance, changes in the expansion stress in the tank and changes in the strain of the outer wall of the tank during the hydrogen absorption and desorption process of the hydrogen storage tank 1, and has a variety of hydrogen absorption / desorption modes (constant current / constant pressure), accurate testing, and simple operation, so that the various filling amounts of different hydrogen storage alloy powders 2 can be targeted to perform anisotropic performance tests during the hydrogen absorption and desorption process, with high testing efficiency, and can realize real-time and accurate monitoring of the stress and strain of the metal hydride hydrogen storage tank 1 during the hydrogen absorption / desorption process, providing an accurate and efficient evaluation method for the production, filling and use safety of the metal hydride hydrogen storage tank 1, providing data support for the improvement of the metal hydride hydrogen storage system, and also providing reference significance for the future storage and transportation of hydrogen in a more effective way.

[0055] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. All equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides, characterized in that: The hydrogen storage tank (1) comprises a straight-cylindrical tank body (101), an upper flange (102) and a lower flange (103) respectively mounted on the top and bottom ends of the straight-cylindrical tank body (101) and integrally formed with the straight-cylindrical tank body (101); an upper flange cover (3) is mounted on the upper flange (102) via fastening bolts (5); a lower flange cover (4) is also mounted on the lower flange (103) via fastening bolts (5); a pressure sensor (7) is threadedly connected at the center position of the top end of the upper flange cover (3); a sensing end (12) of the pressure sensor (7) passes through the top end of the upper flange cover (3) and is flush with the bottom end of the upper flange cover (3); and a plurality of strain gauges (8) distributed in the circumferential direction and located at the axial center position of the straight-cylindrical tank body (101) are provided on the circumferential surface of the straight-cylindrical tank body (101).

2. A multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides according to claim 1, characterized in that: A sealing gasket (6) is provided between the upper flange cover (3) and the upper flange (102) and between the lower flange cover (4) and the lower flange (103); a through hole (9) connected to the straight cylinder tank body (101) is provided at the center of the bottom end of the lower flange cover (4); and a filter element (10) is provided at the top end of the lower flange cover (4) for preventing hydrogen storage alloy powder (2) from entering the pipeline through the through hole (9).

3. The multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides according to claim 1, characterized in that: The pressure sensor (7) is electrically connected to an electric signal acquisition card (13) via a wire, the electric signal acquisition card (13) is electrically connected to a computer (15) via a wire, the electric signal acquisition card (13) is also electrically connected to a mass flow meter (16) and a digital pressure gauge (17) via a wire, the strain gauge (8) is electrically connected to a strain gauge (14) via a wire, and the strain gauge (14) is also electrically connected to the computer (15) via a wire.

4. The multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides according to claim 1, characterized in that: The invention also comprises a first pipeline (18), a second pipeline (19) and a third pipeline (20) which are connected to each other. A sixth valve (21), a fifth valve (22) and a seventh valve (23) are provided on the first pipeline (18) in sequence for controlling the on and off of the first pipeline (18). One end of the sixth valve (21) is connected to the seventh valve (23) through the fifth valve (22), the other end of the sixth valve (21) is connected to the through hole (9) on the lower flange cover (4), and the other end of the seventh valve (23) is connected to the equipment to be filled with hydrogen.

5. The multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides according to claim 4, characterized in that: The second pipeline (19) is provided with a third valve (24) and a first valve (25) for controlling the on and off of the second pipeline (19) in sequence; one end of the third valve (24) is connected to the first valve (25); the other end of the third valve (24) is connected to the fifth valve (22) and the sixth valve (21) respectively through the digital pressure gauge (17); the other end of the first valve (25) is connected to a high-pressure gaseous hydrogen storage tank (26).

6. The multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides according to claim 5, characterized in that: The third pipeline (20) is provided with a pressure reducing valve (27) and a second valve (28), a fourth valve (29) and an eighth valve (30) for controlling the on and off of the third pipeline (20) in sequence. One end of the pressure reducing valve (27) is connected to the first valve (25) and the third valve (24) respectively. The other end of the pressure reducing valve (27) is connected to the mass flow meter (16) through the second valve (28). The mass flow meter (16) is connected to a vacuum pump (31) through the fourth valve (29) and the eighth valve (30). One end of the fourth valve (29) and the eighth valve (30) are also connected to the fifth valve (22) and the seventh valve (23) respectively.

7. A multifunctional detection method for the hydrogen absorption and desorption process of metal hydrides, characterized in that: The method is based on the multifunctional detection device for the hydrogen absorption and desorption process of metal hydrides according to any one of claims 1 to 6, comprising: using the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) to absorb hydrogen and detect the hydrogen absorption process and using the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) to desorb hydrogen and detect the desorption process; Wherein, the method of using the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) to absorb hydrogen and detecting the hydrogen absorption process comprises: First, the first valve (25), the third valve (24) and the sixth valve (21) are opened, and then high-purity hydrogen is continuously introduced into the hydrogen storage tank (1) at a constant hydrogen absorption pressure of 2 MPa, so that the hydrogen storage alloy powder (2) gradually begins to absorb hydrogen until the hydrogen absorption is completed; at the same time, during the hydrogen absorption process, the pressure sensor (7) and the strain gauge (14) perform real-time detection of the expansion stress of the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) and the strain of the outer wall of the hydrogen storage tank (1) until the hydrogen absorption is completed.

8. The multifunctional detection method for the hydrogen absorption and desorption process of metal hydrides according to claim 7, characterized in that: The method of using the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) to release hydrogen and detecting the hydrogen release process comprises: The test procedure of the mass flow meter (16) is started. The mass flow meter (16) is firstly adjusted to zero. Then the pressure of the pressure reducing valve (27) is adjusted to 0.8 MPa. Then the sixth valve (21), the third valve (24), the seventh valve (23), the fourth valve (29) and the second valve (28) are opened in sequence. Then the hydrogen release begins. When the reading of the mass flow meter (16) drops to 0 and remains unchanged for 10 minutes, the hydrogen release process is completed. Meanwhile, during the hydrogen release process, the pressure sensor (7) and the strain gauge (14) detect the expansion stress of the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) and the strain of the outer wall of the hydrogen storage tank (1) in real time until the hydrogen release is completed.

9. A multifunctional detection method for the hydrogen absorption and desorption process of metal hydrides according to claim 8, characterized in that: Before using the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) to absorb and release hydrogen, the method further comprises: The hydrogen storage tank (1) to be tested with the strain gauge (8) attached is placed in a constant temperature water bath; then the leads of the pressure sensor (7), the mass flow meter (16) and the digital pressure gauge (17) are connected to the electrical signal acquisition card (13); then the leads of the strain gauge (8) are connected to the strain gauge (14), the strain gauge (14) is turned on, and the pressure test program and strain test program installed on the computer (15) are opened, and the strain data in the test program is cleared.

10. A multifunctional detection method for the hydrogen absorption and desorption process of metal hydrides according to claim 8, characterized in that: After the hydrogen storage alloy powder (2) in the hydrogen storage tank (1) is used to absorb and release hydrogen, the method further comprises: The expansion stress value inside the hydrogen storage tank (1) and the strain value of the outer wall of the hydrogen storage tank (1) detected in real time by the pressure sensor (7) and the strain gauge (14) during the hydrogen absorption and desorption process are obtained and recorded, and then, based on the recorded data, a curve of the change of the expansion stress inside the hydrogen storage tank (1) and the strain outside the hydrogen storage tank (1) with the hydrogen absorption / desorption time, as well as a curve of the change of the hydrogen desorption amount with time are drawn.

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