Repair method for preventing solid hydrogen storage material from absorbing hydrogen due to air suck-back

Abstract

The invention provides a method for repairing a solid hydrogen storage material which does not absorb hydrogen due to air suck-back. An isolation layer is formed outside the solid hydrogen storage material through air suck-back, so that hydrogen is prevented from entering the material. The repairing method adopts a physical or chemical method to break the isolating layer, and comprises the following steps: step 1, preventing air from being sucked back into the solid hydrogen storage container; 2, removing residual air in the solid hydrogen storage container; step 3, adopting a heating and quenching mode to enable the isolating layer to generate cracks; and step 4, expanding the crack by adopting a pressure difference increasing mode, and finally causing the separation layer to be fractured. The repairing method provided by the invention has remarkable beneficial effects in the aspects of recovering the hydrogen storage performance, prolonging the service life, improving the operation feasibility, protecting the material performance and the like, and has important significance in promoting the development and application of a solid hydrogen storage technology.

Description

Technical Field

[0001] This invention relates to a method for repairing solid hydrogen storage materials, specifically a method for repairing solid hydrogen storage materials that fail to absorb hydrogen due to backflow of air, belonging to the field of solid hydrogen storage technology. Background Technology

[0002] With the increasing global demand for clean energy, hydrogen energy, as an efficient and clean energy carrier, has attracted widespread attention. Solid-state hydrogen storage technology has become a research hotspot in the field of hydrogen storage due to its advantages such as high hydrogen storage density and good safety.

[0003] In practice, it has been found that after repeated charging and discharging of hydrogen, the hydrogen absorption capacity of solid-state hydrogen storage materials decreases significantly, or even stops absorbing hydrogen altogether. Currently, there are relatively few solutions to this problem. Some traditional methods may simply involve replacing the solid-state hydrogen storage material, but this method is costly and wastes resources.

[0004] Therefore, developing an efficient and reliable method for repairing solid hydrogen storage materials is of great significance for improving the practicality and economy of solid hydrogen storage technology. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to repair non-hydrogen-absorbing solid hydrogen storage materials so that they can regain good hydrogen absorption capacity.

[0006] To address the aforementioned technical problems, this invention provides a method for repairing solid hydrogen storage materials. The solid hydrogen storage material has an outer insulating layer. The repair method involves using physical or chemical methods to rupture the insulating layer, allowing hydrogen to enter the interior of the solid hydrogen storage material through the rupture.

[0007] In some embodiments, the solid hydrogen storage material is stored inside a solid hydrogen storage container, and the isolation layer is formed by the reaction of air drawn back into the solid hydrogen storage container with the solid hydrogen storage material.

[0008] In some embodiments, the repair method for solid hydrogen storage materials includes the following main steps: Step 1: Prevent air from being drawn back into the solid hydrogen storage container; Step 2: Remove residual air from the solid hydrogen storage container; Step 3: Use a heating and rapid cooling method to cause cracks in the isolation layer; Step 4: Increase the pressure difference to expand the crack, causing the isolation layer to rupture.

[0009] In some embodiments, step 1 includes the following specific operational steps: checking the solid hydrogen storage container and the pipeline connected to the solid hydrogen storage container, determining the cause of air backflow and eliminating the cause, and preventing air from backflowing into the solid hydrogen storage container.

[0010] In some embodiments, step 2 includes the following specific steps: evacuating and purging the solid hydrogen storage container to ensure that all residual air inside the container is removed.

[0011] In some embodiments, step 3 includes the following sub-steps: Step 3.1: Heat the solid hydrogen storage material to near its maximum design temperature; Step 3.2: Use a rapid cooling method to cool the solid hydrogen storage material to near room temperature, causing cracks in the isolation layer due to rapid thermal expansion and contraction.

[0012] In some embodiments, a cooling system is used in step 3.2 to accelerate the cooling of the solid hydrogen storage material.

[0013] In some embodiments, step 3 further includes the following sub-steps: Step 3.3: Charge the solid hydrogen storage material with hydrogen. If the solid hydrogen storage material does not absorb hydrogen, repeat steps 3.1 and 3.2 until the solid hydrogen storage material begins to absorb hydrogen.

[0014] In some embodiments, step 4 includes the following sub-steps: Step 4.1: Heat the solid hydrogen storage material to the hydrogen absorption temperature to fully absorb hydrogen; Step 4.2: Heat the solid hydrogen storage material to the hydrogen release temperature, release hydrogen and pressurize it to above 0.5 MPa, then open the valve of the solid hydrogen storage container to release pressure to atmospheric pressure; Step 4.3: Close the valve and repeat steps 4.1 and 4.2 above until the pressure can no longer rise above 0.5MPa.

[0015] In some embodiments, step 4 further includes the following sub-steps: Step 4.4: Charge the solid hydrogen storage material with hydrogen. If the hydrogen charging flow rate does not reach the normal hydrogen charging flow rate, repeat steps 4.1 to 4.3 until the hydrogen charging flow rate is normal.

[0016] The beneficial effects of this invention are as follows: The repair method described above effectively removes the external isolation layer of solid hydrogen storage materials, restoring their hydrogen absorption capacity and improving their service life and storage efficiency. This repair method provided by the present invention has significant beneficial effects in restoring hydrogen storage performance, extending service life, improving operational feasibility, and protecting material properties, and is of great significance for promoting the development and application of solid hydrogen storage technology. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an isolation layer formed in a solid hydrogen storage container due to backflow of air.

[0018] The meanings of the markings in the above attached diagrams are as follows: 1 Solid hydrogen storage container 2. Isolation layer 3 Solid-state hydrogen storage materials 4. Air inlet and outlet Figure 1 This is for illustrative purposes only and does not represent that the shape or structure of solid hydrogen storage containers, solid hydrogen storage materials, or isolation layers must be identical to those of other materials. Figure 1 Totally consistent. Detailed Implementation

[0019] This invention analyzes the reasons why solid hydrogen storage materials fail to absorb hydrogen due to backflow of air, and studies methods to restore the hydrogen filling and discharging performance of solid hydrogen storage containers.

[0020] After repeated hydrogen charging and discharging, the hydrogen absorption capacity of solid-state hydrogen storage materials decreases significantly, or even stops. The applicant's research team discovered the reason for this: after charging or discharging, some solid-state hydrogen storage materials are not yet fully saturated. During the cooling process of the solid-state hydrogen storage material, the pressure inside the container may drop to negative pressure. If the valve of the solid-state hydrogen storage container leaks or is misoperated, air may be drawn back into the container and react with the solid-state hydrogen storage material near the inner surface, forming a solid compound. This solid compound completely coats the surface of the hydrogen storage material, forming a structure like... Figure 1 This shows a dense isolation layer.

[0021] When hydrogen is refilled next time, this insulating layer prevents hydrogen from diffusing further into the solid hydrogen storage material, thus preventing contact between hydrogen and the solid hydrogen storage material. This leads to a significant decrease in the hydrogen absorption capacity of the solid hydrogen storage container, or even a complete loss of hydrogen absorption. If the hydrogen absorption problem is not resolved, the solid hydrogen storage container may become unusable. However, in reality, only the surface layer of the solid hydrogen storage material deteriorates; most of the other solid hydrogen storage material has not lost its hydrogen storage capacity. If the entire solid hydrogen storage container and material were to become unusable, it would result in a serious waste.

[0022] Understanding the formation mechanism of the isolation layer helps in developing targeted repair strategies. A dense isolation layer is the root cause of the hydrogen absorption failure in solid-state hydrogen storage containers; therefore, the key to restoring the hydrogen storage capacity of solid-state hydrogen storage containers is to destroy the isolation layer. The repair method provided by this invention targets solid-state hydrogen storage materials with an externally formed dense isolation layer. By employing physical or chemical methods to rupture the isolation layer, hydrogen can enter the interior of the solid-state hydrogen storage material through the rupture and react for absorption, thus restoring the hydrogen storage capacity of the solid-state hydrogen storage material.

[0023] The present invention provides a method for repairing the failure of solid hydrogen storage materials to absorb hydrogen due to backflow of air. The specific solution adopts the following steps.

[0024] Step 1: Prevent air from being drawn back into the solid hydrogen storage container.

[0025] A comprehensive and detailed inspection of the solid hydrogen storage container and its connecting pipelines should be conducted using specialized testing tools (e.g., a gas leak detector). The cause of air backflow should be determined, and appropriate measures should be taken to prevent air from being drawn back into the container. This step is crucial to preventing further deterioration of the isolation layer; only by eliminating the root cause of air backflow can the effectiveness of subsequent repair work be guaranteed.

[0026] This step focuses on inspecting the pipeline connections, checking for aging or damaged seals, and replacing any seals found to be faulty. Check the valves to ensure they are properly closed and leak-free. For example, if a minor leak is found at a pipeline connection, it can be sealed with sealant to prevent air from being drawn back into the solid hydrogen storage container.

[0027] Step 2: Remove the air that has been drawn back into the solid hydrogen storage container and remains there.

[0028] Vacuum pumps and other equipment are used to perform a vacuum purging operation on the solid hydrogen storage container. By continuously purging the vacuum, all residual air inside the solid hydrogen storage container is ensured to be removed, creating a relatively pure environment for the subsequent remediation process and preventing residual air from interfering with the remediation process.

[0029] Connect the vacuum pump to the solid hydrogen storage container, start the vacuum pump, and set an appropriate vacuum level and evacuation time. Generally, the vacuum level can be set to 0.05 Pa, and the evacuation time should last for at least 30 minutes to ensure that all residual air inside the solid hydrogen storage container is removed. During the evacuation process, the vacuum level inside the solid hydrogen storage container can be monitored in real time using a vacuum gauge. Once the vacuum level reaches the set value and remains stable, the vacuum replacement operation is considered complete.

[0030] After identifying and repairing the cause of the air backflow, attempt to perform hydrogen charging. Heat the solid hydrogen storage material to the charging temperature and charge it with hydrogen. If the flow rate is low but the material can still absorb hydrogen, continue charging until the material stops absorbing hydrogen. If it stops absorbing hydrogen, continue with the subsequent repair steps.

[0031] Step 3: Induce cracks in the isolation layer. This step further includes the following sub-steps.

[0032] Step 3.1: Place the solid hydrogen storage container in a heating device, or use the container's own heating mechanism. Set a heating program to slowly raise the temperature to near the maximum design temperature of the solid hydrogen storage material. The heating process requires strict temperature control; it must approach the maximum design temperature to induce thermal expansion and contraction in the material, but not exceed this temperature to avoid damaging the performance of the solid hydrogen storage material. For example, if the maximum design temperature of the solid hydrogen storage material is 320℃, it can be heated to approximately 310℃. The heating rate can be controlled at 5–10℃ / min. During the heating process, the temperature of the solid hydrogen storage material should be monitored in real time using a temperature sensor to ensure a stable and accurate heating process.

[0033] Step 3.2: Use a rapid cooling method (e.g., air cooling or water cooling) to quickly cool the hot solid hydrogen storage material to near room temperature. If air cooling is used, a high-powered fan can be used to blow air onto the solid hydrogen storage container, with the airflow speed set to 5–10 m / s. If water cooling is used, the container can be immersed in flowing cold water to ensure that the solid hydrogen storage material can be quickly cooled to near room temperature, such as around 25°C.

[0034] If there is no cooling system, the solid hydrogen storage container should be allowed to cool naturally as quickly as possible.

[0035] Step 3.3: Connect the hydrogen supply system and perform hydrogen charging on the solid hydrogen storage material. Monitor the hydrogen charging flow rate using a flow meter and observe whether the solid hydrogen storage material absorbs hydrogen.

[0036] If the solid hydrogen storage material still does not absorb hydrogen, it indicates that the cracks in the isolation layer are insufficient to allow hydrogen to enter. Steps 3.1 (heating) and 3.2 (rapid cooling) need to be repeated. After each cycle, a hydrogen filling test should be performed until the solid hydrogen storage material can absorb hydrogen, indicating that the isolation layer has developed enough cracks to provide a channel for hydrogen entry. Then, the solid hydrogen storage container is filled with hydrogen.

[0037] Therefore, the purpose of step 3 above is to first raise the temperature of the solid hydrogen storage material and then rapidly cool it. During cooling, the temperature of the outer insulating layer drops quickly, while the temperature of the internal solid hydrogen storage material drops slowly. This temperature difference causes the expansion rates of the solid hydrogen storage material and the insulating layer to differ. During the rapid thermal expansion and contraction process, the insulating layer may develop cracks due to stress changes.

[0038] Step 4: Expand the crack to further fracture the isolation layer. This step further includes the following sub-steps.

[0039] Step 4.1: Place the solid hydrogen storage material with cracked isolation layer back into the heating device and heat it to the hydrogen absorption temperature of the solid hydrogen storage material, such as 280℃. Maintain this temperature for 10 minutes to allow the solid hydrogen storage material to fully absorb hydrogen. During the hydrogen absorption process, a certain pressure will be generated inside the solid hydrogen storage material. Carefully observe the pressure changes inside the solid hydrogen storage container; this can be monitored in real time using a pressure sensor. Appropriate pressure can promote further crack propagation.

[0040] Step 4.2: Next, heat the solid hydrogen storage material to the hydrogen release temperature to perform the hydrogen release operation. After hydrogen absorption is complete, heat the solid hydrogen storage material to the hydrogen release temperature, for example, 300°C, and begin hydrogen release. Keep the hydrogen release valve closed, allowing the solid hydrogen storage container to pressurize to above 0.5 MPa, for example, to 0.6 MPa. Then quickly open the valve to release the pressure to atmospheric pressure. Record the pressure change data during each pressurization and depressurization process. During this process, the drastic pressure changes will cause existing cracks on the isolation layer to further expand.

[0041] Step 4.3: Close the valve of the solid hydrogen storage container and repeat steps 4.1 and 4.2 above. After each operation, perform a hydrogen charging test on the solid hydrogen storage material and monitor the hydrogen charging flow rate using a flow meter. Through repeated hydrogen absorption, hydrogen release, and pressure buildup and depressurization operations, continuously expand the crack until the pressure buildup can no longer rise above 0.5 MPa. At this point, it indicates that the isolation layer has been fully ruptured, and hydrogen can smoothly enter and exit the interior of the solid hydrogen storage material.

[0042] Step 4.4: Recharge the solid hydrogen storage material with hydrogen. If the hydrogen charging flow rate does not reach the normal hydrogen charging flow rate, it means that the degree of rupture of the isolation layer is still insufficient. Steps 4.1 to 4.3 need to be repeated until the hydrogen charging flow rate is normal. At this point, the solid hydrogen storage material is fully repaired and its normal hydrogen storage performance is restored.

[0043] The purpose of step 4 above is to first increase the pressure inside the solid hydrogen storage container to 0.5 MPa, at which point the pressure inside and outside the isolation layer is also 0.5 MPa. At the instant the valve is rapidly opened, a relatively large pressure difference is created inside and outside the isolation layer. This pressure difference causes the isolation layer to rupture further. Once ruptured, the isolation layer completely fails to isolate hydrogen from the solid hydrogen storage material, and the hydrogen storage performance of the solid hydrogen storage container returns to normal.

[0044] The detailed embodiments described above clearly demonstrate the actual operation process of the solid hydrogen storage material repair method of the present invention, providing specific guidance for the application of this method. This repair method has the following beneficial effects.

[0045] Restoring hydrogen storage performance: The repair method of the present invention can effectively break the isolation layer on the outside of the solid hydrogen storage material, allowing hydrogen to smoothly enter the interior of the solid hydrogen storage material for reaction and absorption, thereby restoring the hydrogen storage capacity of the solid hydrogen storage material, improving its hydrogen storage efficiency in practical applications, and meeting the performance requirements of solid hydrogen storage materials in energy storage and transportation fields.

[0046] Extended service life: Compared to directly replacing solid hydrogen storage materials, this repair method significantly extends the service life of solid hydrogen storage materials by removing the isolation layer, reducing usage costs and improving resource utilization.

[0047] High operational feasibility: The steps and techniques used in the entire repair method, such as heating, cooling, vacuuming, hydrogen filling and releasing, are all based on existing mature technologies and equipment. The operation is relatively simple and easy to implement in actual production and application. It does not require complex processes and expensive equipment investment, and has high feasibility and economy.

[0048] Protecting material performance: During the repair process, by precisely controlling parameters such as temperature and pressure, the solid hydrogen storage material itself is protected to the greatest extent while removing the isolation layer. This avoids additional damage to the solid hydrogen storage material caused by improper repair operations and ensures that the repaired solid hydrogen storage material can work stably and reliably.

[0049] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method of rejuvenating a solid hydrogen storage material, characterized by, The solid-state hydrogen storage material has an isolation layer outside, the repairing method comprises the following steps of: breaking the isolation layer by physical or chemical method, and then hydrogen can enter the inside of the solid-state hydrogen storage material from the broken part.

2. The method of claim 1, wherein the solid-state hydrogen storage material is a metal hydride. The solid-state hydrogen storage material is stored in a solid-state hydrogen storage container, and the isolation layer is formed by reaction of air sucked into the solid-state hydrogen storage container with the solid-state hydrogen storage material.

3. The method of claim 2, wherein the solid-state hydrogen storage material is a metal hydride. The method comprises the following main steps: Step 1, preventing air from being sucked into the solid-state hydrogen storage container; Step 2, removing residual air in the solid-state hydrogen storage container; Step 3, causing the isolation layer to crack by using a heating and quenching method; Step 4, causing the isolation layer to break by using a pressure difference increasing method.

4. The method of claim 3, wherein the solid-state hydrogen storage material is a metal hydride. The step 1 comprises the following specific operation steps: checking the solid-state hydrogen storage container and pipelines connected with the solid-state hydrogen storage container, judging the cause of air sucking and removing the cause, and preventing air from being sucked into the solid-state hydrogen storage container.

5. The method of claim 3, wherein the solid-state hydrogen storage material is a metal hydride. The step 2 comprises the following specific operation steps: vacuumizing and replacing the solid-state hydrogen storage container to ensure that all residual air in the container is removed.

6. The method of claim 3, wherein the solid-state hydrogen storage material is a metal hydride. The step 3 comprises the following sub-steps: Step 3.1, heating the solid-state hydrogen storage material to a temperature close to the highest design temperature thereof; Step 3.2, cooling the solid-state hydrogen storage material to a temperature close to normal temperature by using a rapid cooling method, and causing the isolation layer to crack due to rapid thermal expansion and cold contraction.

7. The method of claim 6, wherein the solid-state hydrogen storage material is a metal hydride. The cooling system is used to accelerate cooling of the solid-state hydrogen storage material in the step 3.

2.

8. The method of claim 6, wherein the solid-state hydrogen storage material is a metal hydride. The step 3 further comprises the following sub-steps: Step 3.3, hydrogen charging is performed on the solid-state hydrogen storage material, if the solid-state hydrogen storage material does not absorb hydrogen, steps 3.1 and 3.2 are repeated until the solid-state hydrogen storage material starts to absorb hydrogen.

9. The method of claim 3, wherein the solid-state hydrogen storage material is a metal hydride. The step 4 comprises the following sub-steps: Step 4.1, heating the solid-state hydrogen storage material to a hydrogen absorption temperature to sufficiently absorb hydrogen; Step 4.2, heating the solid-state hydrogen storage material to a hydrogen release temperature to release hydrogen, and pressurizing to more than 0.5 MPa, and then opening a valve of the solid-state hydrogen storage container to release pressure to normal pressure; Step 4.3, closing the valve, and repeating steps 4.1 and 4.2 until the pressure cannot be increased to more than 0.5 MPa.

10. The method of claim 9, wherein the solid-state hydrogen storage material is a metal hydride. The step 4 further comprises the following sub-steps: Step 4.4, hydrogen charging is performed on the solid-state hydrogen storage material, if the hydrogen charging flow rate does not reach a normal hydrogen charging flow rate, steps 4.1 to 4.3 are repeated until the hydrogen charging flow rate is normal.

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