Visual circulating hydrogen charging and discharging test device for hydrogen storage material

Abstract

The invention belongs to the technical field of hydrogen charging and discharging tests, and discloses a hydrogen storage material visual circulating hydrogen charging and discharging test device which comprises a gas source unit, a pressurization control system, a pressure relief and safety protection system and a visual hydrogen storage reaction container. All the units are in pipeline connection through standard interfaces (such as 1 / 4 'FNPT), and an experiment closed loop with sealing performance, circularity and safety redundancy functions is integrally formed. According to the visual circulating hydrogen charging and discharging test device, the transparent observation window module is introduced in the structural design, the high-strength glass window is combined with the metal sealing ring structure, and on the basis that the high-pressure sealing requirement is met, an operator is endowed with the real-time visual observation capability on the state change of the solid hydrogen storage material in the reaction cavity. According to the design, visual operation is realized in a laboratory hydrogen storage reaction system for the first time, a visual verification basis is provided for phenomena such as material expansion behavior, color change and pulverization failure, and the method is particularly suitable for researching microscopic state evolution in a hydrogen absorption and desorption process.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen charging and discharging tests, and in particular relates to a hydrogen storage material visual cycle charging and discharging test device. Background Art

[0002] Solid-state hydrogen storage materials may pulverize after repeated hydrogen absorption and desorption, which will cause the gaps between the materials to become smaller and smaller, reduce the mass transfer efficiency, and may increase the local stress of the solid-state hydrogen storage equipment. Therefore, it is necessary to cyclically charge and discharge hydrogen into the solid-state hydrogen storage material and observe the state of the solid-state hydrogen storage material in real time to monitor its pulverization characteristics and accumulation. At present, there is no visual solid-state hydrogen storage material cyclic hydrogen charging and discharging device. If a traditional invisible container is used, it cannot be observed during the cycle. Opening the cavity for observation after the cycle is likely to cause hydrogen explosion safety accidents. Opening the cavity also requires replacement and other processes, which is inefficient and will change the accumulation situation. Therefore, it is impossible to carry out the evolution law of pulverization and accumulation of solid-state hydrogen storage materials under the conditions of cyclic charging and discharging hydrogen.

[0003] The closest existing technology is the in-situ hydrogenation test system developed by Chiu et al., which embedded a sapphire window in a stainless steel sample cavity. This device can simultaneously collect PCT curves and perform Raman / infrared characterization under conditions of 4.5 MPa and 723 K to track the hydrogen absorption and desorption behavior of solid-state hydrogen storage materials such as MgH2. Subsequently, the Hattrick-Simpers team proposed a high-throughput optical cavity with a 60 mm diameter sapphire window, with a pressure resistance increased to 10 MPa, which can load 19 powder samples at a time and perform backscattered Raman measurements. These two types of systems still use the traditional Sieverts volume method, mainly relying on single-point pressure and temperature to infer hydrogen content. They lack continuous visualization of the macroscopic evolution of the morphology and multi-physical field coupling monitoring, and the measurement error will be significantly amplified as the sample density decreases.

[0004] However, the above-mentioned visualization cavity is mainly used to collect spectra through sapphire, rather than to directly observe the appearance of the material. The sapphire window is expensive and the field of view is limited to an aperture of about 50mm. It cannot fully observe macroscopic failure morphologies such as powder agglomeration and volume expansion ([pubmed.ncbi.nlm.nih.gov][2]), but can only collect the spectrum emitted by the material. In contrast, the quartz glass used in this patent is not only cheaper, but also allows for direct visual observation of material powder accumulation and other conditions. In addition, the safety protection of the above-mentioned patent relies solely on single-stage mechanical pressure relief and does not establish multi-layer redundancy of bursting discs, electromagnetic isolation, and interlocks in accordance with NASA hydrogen system safety standards. Once the seal fails, it is easy to cause rapid leakage of hydrogen and threaten operational safety ([energy.gov][4]). Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a hydrogen storage material visual cycle charging and discharging hydrogen testing device.

[0006] The present invention is achieved by providing a hydrogen storage material visual cycle charging and discharging hydrogen test device comprising:

[0007] The gas source unit, pressure control system, pressure relief and safety protection system, and visual hydrogen storage reaction vessel are connected by pipes through standard interfaces (such as 1 / 4" FNPT), forming an experimental closed loop with sealing, circulation and safety redundancy functions.

[0008] Furthermore, in the gas source path, the driving gas pressure enters from PG01, filters out impurities through PFO1, and then controls the gas flow through the electrical proportional valve and multi-stage solenoid valve (SV01-SV04) and guides it to the high-pressure hydrogen injection path; the gas is then pressurized to the required pressure range (0–20 MPa) by the motor-driven compression mechanism (PPO2), and the pressure is monitored at PT02 and PT03; during the hydrogen injection process, the gas enters the core test cavity - a visual solid hydrogen storage material container - through the pneumatic switching valve FO03.

[0009] Furthermore, temperature transmitters TTO1-TTO4 are provided on both sides of the cavity for real-time monitoring of changes in thermal properties of the material during the reaction process.

[0010] Furthermore, the visual reaction chamber structure consists of double-end flanges, window blocks, main chamber cylinder and end cover structure; the transparent observation windows on both sides adopt a combination of high-strength glass and sealing gasket structure, installed in the end face groove, and uniformly pre-tightened by high-strength bolts to achieve visual transparency in a high-pressure sealing environment; the internal cavity is filled with hydrogen storage material through the middle filling area, which can withstand high temperature and high pressure environment; the added temperature measuring thermocouples, pressure sensors, etc. enable the parameters of the hydrogen charging and discharging process to be collected in real time, providing a basis for subsequent data analysis.

[0011] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0012] This patent enables the cyclic charging and decharging of solid-state hydrogen storage materials, and allows for direct observation of the material's changing state during the cycle. Image recognition technology can be used to statistically analyze how the material's particle size and stacking height change with increasing charging and decharging cycles, allowing for intuitive observation of changes in the material's state during hydrogen absorption and desorption. This is of great significance for research into the absorption and desorption patterns of solid-state hydrogen storage materials.

[0013] The device boasts a compact structure and clear logic, with each module independently replaceable or adjustable, making it suitable for evaluating the charging and decharging performance of a variety of hydrogen storage materials. Its visual design offers significant advantages over traditional closed vessels in terms of intuitive monitoring, fault diagnosis, and experimental teaching. It also facilitates the study of multi-physics field coupling responses during dynamic hydrogen absorption and desorption processes, making it an important foundational platform for experimental verification of hydrogen storage materials.

[0014] Existing solid-state hydrogen storage material performance evaluation devices are mostly based on fully enclosed metal containers. While these offer advantages in pressure resistance and thermal insulation, they generally lack intuitive feedback on the reaction process, making it difficult to promptly identify state changes during the initial material cycle, decay analysis, or reaction anomaly monitoring. Furthermore, most systems have a low level of integration, lacking systematic integration of gas path control, temperature and pressure acquisition, and safety linkage. This results in complex operation and long debugging cycles, limiting the implementation of high-throughput experiments and high-resolution dynamic analysis of material parameters.

[0015] The proposed visual cyclic hydrogen charging and discharging test device incorporates a transparent observation window module into its structural design. This module leverages the generally low operating pressure of solid-state hydrogen storage materials (generally no more than 5 MPa). The high-strength glass window combined with a metal sealing ring structure allows the operator to visually observe the state changes of the solid-state hydrogen storage material within the reaction chamber in real time, while meeting high-pressure sealing requirements. This design, for the first time, enables visual operation in a laboratory hydrogen storage reaction system, providing a straightforward basis for verifying phenomena such as material expansion behavior, color change, and pulverization failure. It is particularly suitable for studying the microscopic evolution of the state during hydrogen absorption and desorption.

[0016] The device's internal gas flow system is designed with a modular design. The drive gas is precisely controlled via a proportional valve and a multi-stage solenoid valve, and hydrogen is steadily compressed into the reaction chamber via a high-pressure booster. The gas flow is equipped with a two-way pressure transmitter and a bypass control valve for real-time monitoring and adjustment of the hydrogen injection pressure, ensuring stability and repeatability during the charging process. Furthermore, the gas discharge path is interconnected with the safety relief module, automatically releasing pressure in the event of abnormal chamber pressure or overheating, ensuring safe operation of the reaction system and providing a complete experimental safety closed-loop design.

[0017] To address the temperature response hysteresis issue of traditional systems, the device embeds multiple temperature transmitters within the cavity, located at the front, middle, and rear of the material. Combined with a high-sampling-rate data acquisition system, this allows for dynamic monitoring of the temperature field along the axial direction. This layout reveals differences in heat release or endothermic behavior during hydrogen absorption and desorption in different sections of the material, providing high-dimensional input parameters for subsequent material thermal field control and reaction kinetics modeling.

[0018] Standard flanges and bolted connections enable quick assembly and disassembly, and a built-in window for packing replacement facilitates multi-batch material cycle testing. The test chamber and gas path utilize modular interfaces (1 / 4" FNPT) for excellent compatibility and maintainability. All measurement signals (temperature, pressure, and mass flow) are uniformly output to a host computer for plotting key performance graphs, such as PT response curves and absorption and release rate fitting curves, significantly improving data systematization and utilization efficiency.

[0019] Overall, this experimental system not only evaluates the charging and discharging performance of solid-state hydrogen storage materials, but also incorporates several technological advancements, including structural visualization, data integration, and a closed-loop safety system, significantly enhancing the ability to discern process details. Compared to traditional devices, this solution is more suitable for complex experimental tasks such as early material screening, reaction mechanism research, and application simulation. It represents an experimental platform design that prioritizes both basic research and engineering application.

[0020] Conduct hydrogen cycle testing of solid-state hydrogen storage materials, including their pulverization, stacking, and expansion characteristics, and charge a testing fee. Also, sell hydrogen cycle testing equipment for solid-state hydrogen storage materials and charge an equipment fee.

[0021] The present invention fills the research difficulties on the hydrogen charging and discharging process of solid hydrogen storage materials at home and abroad.

[0022] The patent of this invention solves the problem of testing the performance parameters of solid-state hydrogen storage materials and the problem of observing the hydrogen absorption and desorption state of solid-state hydrogen storage materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of a hydrogen storage material visual cycle charging and discharging hydrogen test device provided by an embodiment of the present invention.

[0024] Figure 2 The present invention provides a visual solid-state hydrogen storage material hydrogen cycle test chamber. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] The cyclic evaluation of traditional solid-state hydrogen storage materials mostly relies on gravimetric methods or pressure-composition-temperature (PCT) curves. The experimental process is basically carried out in an opaque high-pressure chamber. Microscopic phase changes, volume expansion, and particle agglomeration can only be inferred through sampling or offline characterization afterwards. This "black box" measurement mode cannot capture fast-time failure mechanisms, nor can it determine the real-time correlation between material cracking and pulverization. As a result, experimenters lack a direct chain of evidence when constructing material-process-performance mapping. When the industry is screening hydrogen storage materials with high cycle life, cyclic aging tests of hundreds of hours or more are often required. If an anomaly occurs during the process, the only way to passively shut down is due to pressure fluctuations or abnormal heat flow, which delays production time and increases sample loss.

[0027] This device transforms a traditional fully enclosed high-pressure vessel into a dual-sided optically visible structure, employing a conjugate combination of high-strength soda-lime-silicon-aluminum glass and a bimetallic sealing gasket, along with a finite element-optimized flange preload distribution. Through this window, the color, morphology, and expansion behavior of solid-state hydrogen storage particles can be captured in real time by an industrial camera under in-situ conditions, breaking the experimental bottleneck of "invisible and intangible" conditions and providing first-hand visual evidence for fault mechanism determination.

[0028] The gas circuit design utilizes a two-stage electrical proportional valve and a four-stage high-frequency response solenoid valve to achieve linked flow and pressure regulation. The inlet utilizes a 0.01μm ceramic membrane and pressure swing adsorption (PSA) micro-deoxygenation cascade filter to ensure the hydrogen dew point entering the compression chamber is below –70°C. The reciprocating compressor's crankshaft-connecting rod mechanism utilizes highly hydrogen-resistant martensitic stainless steel, coupled with nitrided piston rings. This achieves a linear pressure ramp rate of 0.5 MPa / s at 800 r / min. A dual-ended pressure sensor provides real-time closed-loop control of the inlet and outlet differential pressure, preventing sample particle ejection or reagent delamination caused by sudden pressure fluctuations.

[0029] A hybrid array of thin-film platinum resistors and C-type thermocouples is attached to the device's walls. Using a multi-channel temperature acquisition module for spatiotemporal interpolation, the device can resolve transient exothermic peaks within 0.2K. A collaborative algorithm dynamically adjusts the proportional valve duty cycle based on the rate of temperature rise, ensuring uniform heat dissipation during each hydrogen injection phase and preventing localized hot spots from causing thermal shock failure of the glass window. This approach not only increases safety margins but also reduces internal stress in the material caused by thermal gradients, thereby extending the repeatability of cycle life assessments.

[0030] The safety protection system utilizes a bursting disc, a spring-loaded safety valve, and dual hardware and software interlocks. The bursting disc responds in milliseconds, instantly releasing energy in response to overpressure. The safety valve maintains a repeatable opening accuracy of 0.3 MPa differential pressure, providing excellent protection against long-term, slow-rising faults. The PLC calculates multi-dimensional thresholds based on pressure, temperature, and gas flow. If an anomaly occurs, it immediately closes the upstream check valve and switches the bypass line, minimizing the hydrogen release path. Compared to a single mechanical pressure relief solution, this layered redundant architecture reduces system failure rates by an order of magnitude.

[0031] The real-time data fusion module, based on tensor convolution and Kalman filtering, simultaneously maps optical images, cavity pressure decay curves, and temperature gradient fields into a hydrogen absorption and desorption estimation model, outputting cycle efficiency and decay slope. After the first few dozen cycles, experimenters can predict the material's capacity retention after more than 100 cycles, significantly shortening industrial screening cycles. The accompanying software interface connects with automated sample preparation robots, forming a closed-loop, high-throughput solid-state hydrogen storage material evaluation platform, providing reliable foundational data for the engineering of next-generation hydrogen energy systems.

[0032] The principle of this test device is as follows:

[0033] The visual cyclic charging and discharging hydrogen test device for solid-state hydrogen storage materials mainly consists of a gas source, a pressurizing system, a gas unloading system, and a visual solid-state hydrogen storage material storage container.

[0034] Its principle diagram is as follows Figure 1 shown.

[0035] The solid-state hydrogen storage material hydrogen cycle test chamber can be visually observed. Figure 2 shown.

[0036] This visual cyclic charging and decharging test device for solid-state hydrogen storage materials consists of four main functional units: a gas source unit, a pressure control system, a pressure relief and safety protection system, and a visual hydrogen storage reaction vessel. Each unit is connected via standard piping interfaces (such as 1 / 4" FNPT), forming a closed experimental loop with sealing, cyclical, and safety redundancy features. The core of the device is to achieve controlled charging and decharging of high-pressure hydrogen in the solid-state hydrogen storage material, enabling visualization and parameter monitoring of the hydrogen adsorption and release process.

[0037] In the gas source path, driving gas pressure enters from PG01, passes through PFO1 to remove impurities, and then is regulated by an electrical proportional valve and multi-stage solenoid valves (SV01-SV04) to direct the gas flow to the high-pressure hydrogen injection path. The gas is then pressurized to the required pressure range (0–20 MPa) by a motor-driven compression mechanism (PPO2), with pressure monitored at PT02 and PT03. During the hydrogen injection process, the gas enters the core test chamber—the container for visually visible solid-state hydrogen storage materials—through the pneumatic switching valve FO03. Temperature transmitters TTO1–TTO4 are located on both sides of this chamber to monitor changes in the material's thermal properties during the reaction in real time.

[0038] The reaction chamber structure can be visually observed. Figure 2 As shown, it consists of a double-end flange, a window block, a main cavity cylinder, and an end cover structure. The transparent observation windows on both sides are made of a combination of high-strength glass and a sealing gasket structure, installed in the end face grooves. High-strength bolts are uniformly pre-tightened to achieve visual transparency in a high-pressure sealing environment. The internal cavity is filled with hydrogen storage materials (such as LaNi5, TiFe and other metal-based alloys) through the central filling area, which can withstand high temperature and high pressure environments. The additional temperature measuring thermocouples and pressure sensors enable real-time collection of hydrogen charging and discharging process parameters, providing a basis for subsequent data analysis.

[0039] During operation, the control system adjusts the hydrogen charging and discharging sequence according to a pre-programmed procedure. During the hydrogen storage phase, hydrogen enters the chamber under high pressure and undergoes an adsorption reaction with the material, releasing heat and manifesting as a temperature rise. The reaction rate is regulated by signals such as PT01 and TT01-04. During the hydrogen release phase, the exhaust path (AVO02, FO02) is opened, and hydrogen is released into the atmospheric pressure container. Manual and filtration components such as TWO1 and MFO1 ensure process safety and cleanliness. Throughout the cycle, the operator can observe changes in the material's color, volume, or phase through a viewing window to determine whether the reaction is sufficient or degradation has occurred.

[0040] The device boasts a compact structure and clear logic, with each module independently replaceable or adjustable, making it suitable for evaluating the charging and decharging performance of a variety of hydrogen storage materials. Its visual design offers significant advantages over traditional closed vessels in terms of intuitive monitoring, fault diagnosis, and experimental teaching. It also facilitates the study of multi-physics field coupling responses during dynamic hydrogen absorption and desorption processes, making it an important foundational platform for experimental verification of hydrogen storage materials.

[0041] Existing solid-state hydrogen storage material performance evaluation devices are mostly based on fully enclosed metal containers. While these offer advantages in pressure resistance and thermal insulation, they generally lack intuitive feedback on the reaction process, making it difficult to promptly identify state changes during the initial material cycle, decay analysis, or reaction anomaly monitoring. Furthermore, most systems have a low level of integration, lacking systematic integration of gas path control, temperature and pressure acquisition, and safety linkage. This results in complex operation and long debugging cycles, limiting the implementation of high-throughput experiments and high-resolution dynamic analysis of material parameters.

[0042] The proposed visual cyclic hydrogen charging and decharging test device incorporates a transparent observation window module into its structural design. This utilizes a high-strength glass window combined with a metal sealing ring. While meeting high-pressure sealing requirements, it enables the operator to visually observe the state changes of the solid-state hydrogen storage material within the reaction chamber in real time. This design, for the first time, enables visual operation in a laboratory hydrogen storage reaction system, providing a foundation for intuitive verification of material expansion behavior, color changes, and pulverization failure. It is particularly suitable for studying the microscopic evolution of hydrogen absorption and desorption processes.

[0043] The device's internal gas flow system is designed with a modular design. The drive gas is precisely controlled via a proportional valve and a multi-stage solenoid valve, and hydrogen is steadily compressed into the reaction chamber via a high-pressure booster. The gas flow is equipped with a two-way pressure transmitter and a bypass control valve for real-time monitoring and adjustment of the hydrogen injection pressure, ensuring stability and repeatability during the charging process. Furthermore, the gas discharge path is interconnected with the safety relief module, automatically releasing pressure in the event of abnormal chamber pressure or overheating, ensuring safe operation of the reaction system and providing a complete experimental safety closed-loop design.

[0044] To address the temperature response hysteresis issue of traditional systems, the device embeds multiple temperature transmitters within the cavity, located at the front, middle, and rear of the material. Combined with a high-sampling-rate data acquisition system, this allows for dynamic monitoring of the temperature field along the axial direction. This layout reveals differences in heat release or endothermic behavior during hydrogen absorption and desorption in different sections of the material, providing high-dimensional input parameters for subsequent material thermal field control and reaction kinetics modeling.

[0045] Standard flanges and bolted connections enable quick assembly and disassembly, and a built-in window for packing replacement facilitates multi-batch material cycle testing. The test chamber and gas path utilize modular interfaces (1 / 4" FNPT) for excellent compatibility and maintainability. All measurement signals (temperature, pressure, and mass flow) are uniformly output to a host computer for plotting key performance graphs, such as PT response curves and absorption and release rate fitting curves, significantly improving data systematization and utilization efficiency.

[0046] Overall, this experimental system not only evaluates the charging and discharging performance of solid-state hydrogen storage materials, but also incorporates several technological advancements, including structural visualization, data integration, and a closed-loop safety system, significantly enhancing the ability to discern process details. Compared to traditional devices, this solution is more suitable for complex experimental tasks such as early material screening, reaction mechanism research, and application simulation. It represents an experimental platform designed for both fundamental research and engineering application.

[0047] The present invention is specifically implemented:

[0048] Example 1: Evaluation of Rapid Hydrogen Absorption and Desorption Performance Based on LaNi5 Alloy

[0049] Objective: To evaluate the hydrogen absorption and desorption rate and reversible capacity of LaNi5 metal hydride materials at different hydrogen charging pressures.

[0050] Here are the steps:

[0051] 1. Sample loading: 5.00 g of LaNi5 powder was weighed in an inert atmosphere glove box and placed in the central area of ​​the test chamber, with quartz gauze and stainless steel gaskets limiting its axial movement.

[0052] 2. Device assembly: According to Figure 2 Structure, assemble the window glass, sealing ring and end cover to both ends of the cavity in sequence, and use a torque wrench to gradually pre-tighten the bolts diagonally to the specified torque value to ensure the sealing of the cavity.

[0053] 3. Pretreatment: Vacuum to <10 -2 Pa, introduce 99.999% hydrogen for activation and hydrogen charging twice, each time to 1.5MPa.

[0054] 4. Formal experiment: Set the driving gas source pressure to 0.7 MPa, pressurize the hydrogen to the set pressure (three groups of 0.8, 1.0, and 1.2 MPa) through the electric proportional valve, and record the data of the temperature transmitters TTO1–TTO4 and the pressure sensors PT01 / 03.

[0055] 5. Results Analysis: The reaction rate and thermodynamic stability were determined by observing the material's color change (from silvery white to dark gray), the temperature response peak, and the hydrogen absorption termination pressure plateau through a viewing window. The results showed that the material had the fastest hydrogen absorption rate at 1.0 MPa, with a temperature rise of approximately 18°C ​​within 10 minutes and a stable adsorption platform.

[0056] Example 2: Verification of low-temperature dehydrogenation performance of MgH2 nanocomposite materials

[0057] Objective: To verify the hydrogen release characteristics and stability of ball-milled MgH2 nanocomposites in the medium and low temperature range.

[0058] Here are the steps:

[0059] 1. Material preparation: The mechanically ball-milled MgH2+5wt% Nb2O5 composite material sample (mass 3.00 g) was placed in the center of the inner cavity and sealed on both sides by quartz gaskets to prevent the powder from flowing with the hydrogen.

[0060] 2. Device sealing and leak detection: After assembly is completed, perform a pressure leak test, increase the pressure to 2.0MPa and maintain the pressure for 30 minutes to ensure there is no leakage.

[0061] 3. Heating and dehydrogenation: Connect the device to an external heating belt, set the heating rate to 5°C / min, and the target temperature to 300°C. Record the temperature (TT01–TT04) and pressure change curves in real time.

[0062] 4. Data acquisition and visual observation: When the temperature rises to 270°C, the particles in the observation window clearly expand and the powder color changes from grayish white to light yellow. The pressure slowly rises to 0.15 MPa, indicating that the material dehydrogenation has started. The hydrogen desorption rate is calculated based on the pressure-time curve.

[0063] 5. Result processing: The material completed dehydrogenation at 300°C for 10 minutes, and there was no melting phenomenon in the window, indicating that the powder structure was complete and had good cycle stability and reaction uniformity.

[0064] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with this technical field within the technical scope disclosed by the present invention and within the spirit and principles of the present invention should be covered by the scope of protection of the present invention.

Claims

1. A visual cycle hydrogen charging and discharging test device, characterized in that: The device includes a gas source unit, a pressure boosting control unit, a pressure relief and safety protection unit, and a visual hydrogen storage reaction vessel; each unit is connected to a standard threaded interface through a metal sealed pipeline to form a closed loop, the pressure boosting control unit is configured to increase the hydrogen pressure from the inlet pressure to a set range of 0MPa to 20MPa, and the pressure relief and safety protection unit is configured to automatically release and cut off the gas source when the system pressure exceeds a preset threshold. The visual hydrogen storage reaction vessel is filled with solid hydrogen storage material and is provided with a transparent observation window for directly observing material morphology changes under high pressure and controlled temperature conditions.

2. The device according to claim 1, characterized in that The gas source unit includes a high-purity hydrogen cylinder, a filter assembly and an electric proportional valve. The filter assembly is used to remove particles and moisture, and the electric proportional valve is used to accurately adjust the hydrogen flow entering the boost control unit.

3. The device according to claim 1, characterized in that The boost control unit includes a multi-stage solenoid valve, a proportional valve array and a motor-driven reciprocating compression mechanism arranged in series. A first pressure sensor and a second pressure sensor are respectively installed at the outlet and inlet of the compression mechanism to form a closed-loop pressure control.

4. The device according to claim 1, characterized in that The pressure relief and safety protection unit includes a one-way valve, a safety relief valve and a bursting disc assembly in sequence, and a pneumatic switching valve with position feedback is arranged upstream of the one-way valve to isolate the pipeline from the reaction vessel when an abnormal temperature rise is detected.

5. A visual hydrogen storage reaction container, characterized in that: It includes a main cavity cylinder, double-end flanges, transparent observation windows on both sides and an end cover sealing assembly; the transparent observation window is composed of high-strength glass and metal gaskets laminated together and pre-tightened and fixed to the double-end flanges with uniformly distributed high-strength bolts. A packing area is provided in the middle of the main cavity cylinder for accommodating solid hydrogen storage materials. The designed operating temperature of the container is not higher than 150°C and the designed working pressure is not higher than 20MPa.

6. The reaction container according to claim 5, characterized in that At least two pairs of temperature sensors are distributed axially in the main cavity cylinder, and the signal lines of the temperature sensors are led out through electrical isolation connectors to achieve real-time temperature monitoring.

7. The reaction container according to claim 5, characterized in that The outer wall of the container is provided with a pressure-resistant optical window cover and an industrial camera assembly, and the industrial camera assembly works in conjunction with an external lighting source to collect image data of the hydrogen storage material during the hydrogen charging and discharging cycle.

8. A cyclic hydrogen charging and discharging method performed by the device according to any one of claims 1 to 4, characterized in that: The steps include: a) evacuating the reaction vessel to a predetermined vacuum degree; b) charging hydrogen into the reaction vessel through a pressure boosting control unit and increasing the pressure to a target pressure; c) Maintain the target pressure for a set time and record the temperature, pressure and image data; d) Start the pressure relief and safety protection unit to discharge hydrogen to a low pressure state at a set rate; e) Repeat steps b) to d) to complete the set number of cycles.

9. The method according to claim 8, characterized in that During the charging stage, the charging rate is dynamically adjusted according to the real-time temperature signal to keep the temperature rise of the reaction vessel wall within the preset threshold.

10. The method according to claim 8, characterized in that The acquired image data, temperature data and pressure data are fused to estimate the hydrogen absorption and desorption amount of the hydrogen storage material in real time and output the cycle performance attenuation curve.

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