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Abstract

The application discloses a hydrogenated magnesium composite hydrogen storage briquette permeability test system and method, and relates to the technical field of hydrogen storage materials, in particular to a hydrogenated magnesium composite hydrogen storage briquette permeability test system and method. The system comprises a test device, a vacuum pump and a differential pressure transmitter connected to the test device through pipelines; a hydrogen delivery device connected with a flow controller through a pressure reducing valve, and the flow controller is connected with the test device; wherein, when the briquette permeability is tested, the hydrogen delivery device is used to deliver hydrogen into the test device, the differential pressure transmitter is used to monitor the differential pressure between the two ends of the test device, and the briquette size is used to calculate the briquette permeability. The system can accurately control the test environment, ensure the stability of hydrogen flow, pressure and other parameters during the test, simultaneously, can monitor the differential pressure between the two ends of the test device in real time, and can accurately calculate the permeability of the briquette by combining the size information of the briquette, improve the accuracy and reliability of the test, adapt to different test requirements, and solve the technical defects that the existing technology cannot test the axial and radial permeabilities of the composite hydrogen storage briquette respectively.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen storage permeability testing of magnesium hydride composite hydrogen storage briquettes, and particularly relates to a hydrogen storage permeability testing system and method for magnesium hydride composite hydrogen storage briquettes. BACKGROUND

[0002] Magnesium-based solid-state hydrogen storage technology has the advantages of high hydrogen storage density (7.6wt%), safety, low cost (abundant in raw materials in the earth's crust), and cycle stability, and is one of the important directions for large-scale hydrogen storage technology development at the present stage. However, due to the limitation of reaction thermodynamic characteristics, the high reaction kinetics of magnesium hydride can only fully play a role in application when the heat released or absorbed during the hydrogen absorption or release process is fast enough; if the heat is not released or absorbed in time, the hydrogen absorption or release process of magnesium hydride will stop. Therefore, magnesium hydride hydrogen storage material must have good heat transfer performance during use to continuously and quickly release or absorb hydrogen.

[0003] The magnesium hydride composite hydrogen storage briquette is a cold-pressed product of magnesium hydride powder and high-thermal-conductivity materials (expanded graphite, etc.) in a mold, is an effective device for strengthening bed layer heat transfer, and can uniformly distribute the magnesium hydride powder in the bed layer to prevent stress concentration on the tank body caused by the expansion of the hydrogen storage material during hydrogen absorption due to the agglomeration of the powder.

[0004] At present, the hydrogen storage permeability testing equipment for magnesium hydride composite hydrogen storage briquettes on the market cannot test the axial and radial permeabilities of the composite hydrogen storage briquettes respectively during the permeability testing process of the magnesium hydride composite hydrogen storage briquettes, which results in that the mass transfer performance of the briquette cannot be comprehensively mastered and the hydrogen storage operation cannot be effectively performed. SUMMARY

[0005] The purpose of the present application is to provide a hydrogen storage permeability testing system and method for magnesium hydride composite hydrogen storage briquettes to solve the technical defects that the prior art cannot test the axial and radial permeabilities of the composite hydrogen storage briquettes respectively, which results in that the mass transfer performance of the briquette cannot be comprehensively mastered and the hydrogen storage operation cannot be effectively performed.

[0006] In order to achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0007] In a first aspect, a hydrogen storage permeability testing system for magnesium hydride composite hydrogen storage briquettes is provided, comprising:

[0008] A testing device, to which a vacuum pump and a differential pressure transmitter are connected through pipelines;

[0009] A hydrogen gas delivery device, to which a flow controller is connected through a pressure reducing valve, and the flow controller is connected with the testing device;

[0010] Wherein, when the briquette permeability test is carried out, the hydrogen gas is delivered into the test device through the hydrogen gas delivery device, and the pressure difference between the two ends of the test device is monitored by the pressure difference transmitter, and the briquette permeability is calculated in combination with the briquette size.

[0011] Further, the test device comprises an upper shell and a lower shell, and the upper shell and the lower shell are connected by bolts;

[0012] The upper shell and the lower shell are communicated, and a sample groove is arranged in one end of the upper shell and the lower shell, and the briquette is arranged in the sample groove.

[0013] Further, the end of the lower shell away from the upper shell is the gas inlet end, and the end of the upper shell away from the lower shell is the gas outlet end.

[0014] Further, the cross section of the sample groove is rectangular.

[0015] Further, the briquette is of a rectangular structure.

[0016] Further, the length of the briquette is greater than the length of the test channel formed between the upper shell and the lower shell.

[0017] Further, the upper shell and the lower shell are of the same structure.

[0018] Further, the hydrogen gas delivery device is a hydrogen gas cylinder.

[0019] Further, the briquette is a cube.

[0020] In the second aspect, a hydrogen storage briquette permeability test method of magnesium hydride composite is provided, and the method is carried out by using the test system as described above, and the method comprises the following steps.

[0021] The displacement gas is input into the pipeline, and the pipeline is repeatedly vacuumized and aerated, so that the hydrogen content in the pipeline reaches a preset value;

[0022] The different hydrogen flow rates into the test device are set by the flow controller, and the pressure difference between the two ends of the test device is obtained by the pressure difference transmitter;

[0023] The briquette permeability is calculated based on the pressure difference and in combination with the sample size.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1、The system can accurately control the test environment by integrating vacuum pumps, differential pressure transmitters, and flow controllers, ensuring the stability of hydrogen flow, pressure, and other parameters during the test process; at the same time, the differential pressure transmitter can monitor the pressure difference between the two ends of the test device in real time, and combined with the size information of the pressure block, the permeability of the pressure block can be accurately calculated, improving the accuracy and reliability of the test; finally, the hydrogen delivery device is connected with the flow controller through the pressure reducing valve, which can easily adjust the input amount and speed of hydrogen, adapt to different test requirements, and solve the technical defects that the existing technology cannot test the axial and radial permeability of the composite hydrogen storage pressure block, which cannot fully grasp the mass transfer performance of the pressure block and cannot effectively perform the hydrogen storage operation.

[0026] 2、The split type test device makes it easier to install, disassemble and replace the pressure block, not only improving the test efficiency, but also reducing the operation difficulty and maintenance cost. At the same time, the smooth flow of hydrogen in the test process is ensured between the upper and lower shells connected to each other, avoiding test errors caused by structural problems. Secondly, the sample tank ensures that the pressure block can be tightly fitted in the tank, reducing the possibility of hydrogen leakage, thereby improving the accuracy of the test.

[0027] 3、Hydrogen enters the test device from the gas inlet end, penetrates through the pressure block, and is discharged from the gas outlet end, making the test process more efficient, because hydrogen can quickly flow through the pressure block and complete the test, while also reducing the residence time of hydrogen in the test device, reducing potential hydrogen leakage and safety hazards.

[0028] 4、The rectangular cross-section helps to form a more uniform gas flow distribution in the sample tank. Compared with circular or other irregular shapes, the rectangular cross-section reduces the accumulation and vortex of gas flow in the corners and edges, thereby improving the accuracy and reliability of the test.

[0029] 5、The rectangular pressure block can more effectively utilize space, achieve full contact with hydrogen, and reduce space waste.

[0030] 6、When the length of the pressure block exceeds the test channel, its two ends can form a tighter contact with the edges of the upper and lower shells, which helps to reduce hydrogen leakage during the test process, thereby improving the sealing and accuracy of the test.

[0031] 7、The upper and lower shells with the same structure have higher interchangeability, which can easily replace damaged or worn parts during maintenance, replacement or upgrading of the test device, without worrying about compatibility issues. This interchangeability improves the reliability and usability of the test device.

[0032] 8. Hydrogen cylinders, as hydrogen delivery devices, have the ability to efficiently store and transport hydrogen. Due to special internal treatment, they can withstand high hydrogen pressure, thus achieving effective hydrogen storage. When needed, the hydrogen cylinders can quickly release hydrogen. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the testing device structure in the magnesium hydride composite hydrogen storage block permeability testing system provided by the present invention;

[0035] Figure 2 A schematic diagram of the permeability testing system for magnesium hydride composite hydrogen storage blocks provided by the present invention;

[0036] Figure 3 Flowchart of the permeability testing method for magnesium hydride composite hydrogen storage blocks provided by the present invention;

[0037] In the diagram: 1. Upper shell; 2. Lower shell; 3. Bolt; 4. Sample chamber; 5. Pressure block. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, or the orientation or position relationship when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0042] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] Magnesium-based solid-state hydrogen storage technology has the advantages of high hydrogen storage density (7.6wt%), safety, low cost (abundant in raw materials in the earth's crust), and cycle stability, and is one of the important directions for the development of large-scale hydrogen storage technology at the present stage. However, due to the limitation of reaction thermodynamic properties, the high reaction kinetics of magnesium hydride can only fully play a role in application when the heat released or absorbed during the hydrogen absorption or release process is fast enough; if the heat is not released or absorbed in time, the hydrogen absorption or release process of magnesium hydride will stop. Therefore, magnesium hydride hydrogen storage material must have good heat transfer performance during use in order to continuously and quickly release or absorb hydrogen.

[0045] The magnesium hydride composite hydrogen storage briquette is a kind of effective enhanced bed heat transfer device, which is formed by cold pressing magnesium hydride powder and high thermal conductivity material (expanded graphite, etc.) in a mold, and can make the magnesium hydride powder uniformly distributed in the bed layer, preventing the agglomeration of the powder from causing stress concentration on the tank body due to the hydrogen absorption expansion of the hydrogen storage material.

[0046] At present, the hydrogen storage magnesium composite briquette permeability test equipment on the market cannot test the axial and radial permeability of the hydrogen storage magnesium composite briquette respectively during the permeability test of the hydrogen storage magnesium composite briquette, which cannot comprehensively grasp the mass transfer performance of the briquette and cannot effectively carry out hydrogen storage operation. In order to solve the above technical defects of the prior art, the inventors provide a hydrogen storage magnesium composite briquette permeability test system and method.

[0047] The application will be further described in detail below with reference to the drawings:

[0048] In the first aspect, as shown in Figure 1 and Figure 2 , the application provides a hydrogen storage magnesium composite briquette permeability test system, which comprises a test device, pipes connected to two ends of the test device, valves and differential pressure transmitters installed on the pipes, two ends of the differential pressure transmitters connected to two ends of the test device, one end of the pipe connected to a vacuum pump, the other end of the pipe connected to a pressure reducing valve, a hydrogen gas conveying device connected to the pressure reducing valve, the hydrogen gas conveying device preferably being a hydrogen cylinder, the hydrogen cylinder being connected to the test device through a flow controller, the hydrogen cylinder serving as the hydrogen gas conveying device and having the ability of efficiently storing and conveying hydrogen, and the hydrogen cylinder being able to withstand high hydrogen pressure due to special treatment of the inside of the hydrogen cylinder, thereby achieving effective storage of hydrogen. When needed, the hydrogen cylinder can rapidly release hydrogen. The hydrogen gas conveying device is connected to the test device through the flow controller, wherein, during the permeability test of the briquette 5, the hydrogen gas conveying device conveys hydrogen into the test device through a gas displacement device, and the differential pressure transmitters monitor the pressure difference between the two ends of the test device, and the size of the briquette 5 is combined to calculate the permeability of the briquette 5. During the permeability test of the briquette 5, the system can accurately control the test environment by integrating the vacuum pump, the differential pressure transmitters and the flow controller, so as to ensure the stability of the hydrogen flow, pressure and other parameters during the test; at the same time, the differential pressure transmitters can monitor the pressure difference between the two ends of the test device in real time, and the size information of the briquette 5 can be combined to accurately calculate the permeability of the briquette 5, thereby improving the accuracy and reliability of the test; finally, the gas displacement device is connected to the flow controller through the pressure reducing valve, which can conveniently adjust the input amount and speed of the hydrogen, adapt to different test requirements, and solve the technical defects of the prior art that the axial and radial permeability of the hydrogen storage magnesium composite briquette cannot be tested respectively during the permeability test of the hydrogen storage magnesium composite briquette, which cannot comprehensively grasp the mass transfer performance of the briquette and cannot effectively carry out hydrogen storage operation.

[0049] As Figure 1As shown, the test device includes an upper housing 1 and a lower housing 2, the upper housing 1 and the lower housing 2 are structurally identical, the structurally identical upper housing 1 and the lower housing 2 have higher interchangeability, when the test device is repaired, replaced or upgraded, the damaged or worn parts can be easily replaced without worrying about compatibility problems. This interchangeability improves the reliability and usability of the test device. The upper housing 1 and the lower housing 2 are connected by bolts 3. By using a split test device, it is easier to install, remove and replace the pressure block 5 during the permeation test, which not only improves the test efficiency, but also reduces the operation difficulty and maintenance cost. The upper housing 1 and the lower housing 2 are connected, and a sample groove 4 is formed in one end of the upper housing 1 and the lower housing 2. The cross section of the sample groove 4 is rectangular, and the pressure block 5 is built in the sample groove 4. The smooth flow of hydrogen during the test is ensured between the upper housing 1 and the lower housing 2, which avoids test errors caused by structural problems; the rectangular cross section of the sample groove 4 helps to form more uniform airflow distribution in the sample groove 4. Compared with circular or other irregular shapes, the rectangular cross section reduces the accumulation and vortex of airflow in the corners and edges, thereby improving the accuracy and reliability of the test. As Figure 1 As shown, the end of the lower housing 2 away from the upper housing 1 is the gas inlet end, and the end of the upper housing 1 away from the lower housing 2 is the gas outlet end. Hydrogen enters the test device from the gas inlet end, and after the permeation of the pressure block 5, it is discharged from the gas outlet end, making the test process more efficient, because hydrogen can quickly flow through the pressure block and complete the test, while also reducing the residence time of hydrogen in the test device, reducing potential hydrogen leakage and safety hazards. The pressure block 5 is rectangular in structure, specifically a cube structure. The rectangular pressure block 5 can more effectively utilize space, achieve full contact with hydrogen, and reduce space waste.

[0050] As Figure 1 shown, the length of the pressure block 5 is greater than the length of the test channel formed between the upper housing 1 and the lower housing 2. When the length of the pressure block 5 exceeds the test channel, its two ends can form a tighter contact with the edges of the upper housing 1 and the lower housing 2, which helps to reduce hydrogen leakage during the test, thereby improving the sealing and accuracy of the test. In addition, since the two ends of the pressure block 5 exceed the test channel, it is easier to observe the changes of the pressure block 5 during the test. At the same time, due to the close contact between the pressure block 5 and the upper housing 1, it is easier to record and compare test data, providing strong support for subsequent research and improvement.

[0051] In a second aspect, the embodiment provides a method for testing the permeability of a magnesium hydride composite hydrogen storage pressure block, which is carried out by using the test system as described above, as Figure 3 shown, comprising:

[0052] S101, input replacement gas into the pipeline, and repeatedly vacuumize and aerate to make the hydrogen content in the pipeline reach a preset value; for example, as shown in Figure 2 , the gas in the pipeline is first replaced, the air in the system pipeline is evacuated before the gas in the system is replaced, and inert gases such as helium, nitrogen or argon are delivered into the system pipeline as intermediate replacement gas for gas replacement operation; secondly, the content of the original gas in the system pipeline is reduced by a vacuum pump to improve the gas replacement efficiency; then, as shown in Figure 2 , close the V12 valve, open the remaining V1, V2, V3, V4, V5, V6, V7, V8, V9, V10 and V11 stop valves of the system, and then use the vacuum pump to reduce the pressure in the system pipeline to 0.1 pa; then close the V11 stop valve, open the pressure reducing valve 1 to fill inert gas into the system pipeline, and the filling pressure is adjusted to 2Mpa; after the filling is completed, close the pressure reducing valve 1, and then repeatedly vacuumize and aerate to reduce the air volume fraction to 0.05%; finally, the hydrogen content in the pipeline reaches a preset value, which is 95.5%.

[0053] S102, set different hydrogen flow rates into the test device through the flow controller, and use the differential pressure transmitter to obtain the pressure difference between the two ends of the test device; for example, as shown in Figure 2 , open the V2, V9, V10 and V12 valves, and the gas replacement device adjusts the pressure; specifically, the gas replacement device is a hydrogen cylinder, and the pressure is adjusted to 0.1~2MPa by using the pressure reducing valve 2; different hydrogen flow rates are set by the flow controller, and the differential pressure transmitter p4 is monitored to obtain the pressure difference between the two ends of the test device; in this scheme, the valve V12 is a back pressure valve, which can test the permeability of the briquette under different pressures.

[0054] S103, calculate the permeability of the briquette based on the pressure difference and the size of the sample; for example, based on the pressure difference between the two ends of the test device obtained in the above steps, the size of the briquette 5 is combined to calculate the permeability of the briquette 5; since the hydrogen pressure gradient of the magnesium hydride bed layer is not obvious, the flow belongs to the laminar flow section, which is suitable for Darcy's law, so the permeability can be obtained by the following formula .

[0055]

[0056] In the formula, , the permeability is m 2 ; the volume flow rate is m 3 / s; the dynamic viscosity coefficient is Pa∙s; , the side length of the cubic briquette sample is m; , the pressure difference measured by the differential pressure transmitter is Pa.

[0057] The permeability test method can be used to test the permeability of the magnesium hydride composite hydrogen storage briquette, can accurately control the test environment, ensure the stability of hydrogen flow, pressure and other parameters in the test process, can monitor the pressure difference between the two ends of the test device in real time through the pressure difference transmitter, and can accurately calculate the permeability of the briquette by combining the size information of the briquette, improve the accuracy and reliability of the test, finally, the hydrogen delivery device is connected with the flow controller through the pressure reducing valve, the input amount and speed of hydrogen can be adjusted conveniently, different test requirements can be adapted, and the technical defects that the existing technology cannot test the axial and radial permeabilities of the composite hydrogen storage briquette respectively during the permeability test of the magnesium hydride composite hydrogen storage briquette are solved, which cannot fully grasp the mass transfer performance of the briquette and cannot effectively perform the hydrogen storage operation.

[0058] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit the scope of protection, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: after reading the present application, those skilled in the art can still make various changes, modifications or equivalent replacements to the specific embodiments of the present application, but these changes, modifications or equivalent replacements are all within the scope of protection of the claims of the present application.

Claims

1. A permeability testing system for magnesium hydride composite hydrogen storage briquettes, characterized in that, The application relates to a testing system and a testing method for briquette permeability. The testing device is connected with a vacuum pump and a differential pressure transmitter through pipelines; The hydrogen delivery device is connected with a flow controller through a pressure reducing valve, and the flow controller is connected with the testing device; When the briquette permeability is tested, hydrogen is delivered into the testing device through the hydrogen delivery device, the differential pressure between the two ends of the testing device is monitored by the differential pressure transmitter, and the briquette permeability is calculated by combining the briquette size; The testing device comprises an upper shell (1) and a lower shell (2), and the upper shell (1) and the lower shell (2) are connected through bolts (3); The upper shell (1) and the lower shell (2) are connected and communicate with each other, a sample groove (4) is arranged in one end of the upper shell (1) and the lower shell (2), and a briquette (5) is arranged in the sample groove (4).

2. The hydrogen storage test system of claim 1, wherein, The end, away from the upper shell (1), of the lower shell (2) is an air inlet end, and the end, away from the lower shell (2), of the upper shell (1) is an air outlet end.

3. The hydrogen storage test system of claim 1, wherein, The sample groove (4) has a rectangular cross section.

4. The hydrogen storage test system of claim 1, wherein, The briquette (5) has a rectangular structure.

5. The hydrogen storage test system of claim 1, wherein, The length of the briquette (5) is greater than the length of the testing channel formed between the upper shell (1) and the lower shell (2).

6. The hydrogen storage test system of claim 1, wherein, The upper shell (1) and the lower shell (2) have the same structure.

7. The hydrogen storage test system of claim 1, wherein, The hydrogen delivery device is a hydrogen cylinder.

8. The hydrogen storage system of claim 1, wherein, The valve V12 is a back pressure valve, and the briquette permeability under different pressures can be tested.

9. A method for testing permeability of a hydrogen storage compact of magnesium hydride composite, characterized by, The method is performed by using the testing system according to any one of claims 1-8, and the method comprises the following steps: A displacement gas is input into the pipeline, and vacuumizing and air charging are repeated to make the hydrogen content in the pipeline reach a preset value; Different hydrogen flow rates are set by the flow controller to enter the testing device, and the differential pressure between the two ends of the testing device is obtained by the differential pressure transmitter; The briquette permeability is calculated based on the differential pressure and the sample size.

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