High-pressure Hydrogen Storage Tank Research Articles

Deep learning-driven predictive tools for damage prediction and optimization in composite hydrogen storage tanks

This research presents a comprehensive framework for predicting the damage in lightweight composite high-pressure hydrogen storage tanks and optimizes their design to prevent failure. By integrating advanced analytical methods, numerical analysis, and deep learning techniques, we introduced a novel approach to enhance design optimization and damage prediction. The framework employs the 3D elasticity anisotropy theory to predict mechanical performance, incorporating failure criteria for accurate damage analysis. A parametric study was conducted to examine the effects of thickness, pressure, and diameter on the behavior of the tank. The analytical results were compared against finite element analysis using the WoundSim software, underscoring the significance of the modeling assumptions. Furthermore, we developed a new framework that combines deep neural networks with differential evolution optimization (DNN-DEO) to predict stress and damage in composite pressure vessels while identifying the optimal design parameters (pressure, radius, and thickness) to minimize failure risks and maintain high performance. A graphical user interface (GUI) was also designed to automate calculations and predictions, providing an intuitive tool for users. This integrated approach offers a powerful solution for optimizing the design and operation of lightweight composite hydrogen storage tanks, ensuring the reliability and efficiency of hydrogen storage systems.

Hydrogen storage and refueling options: A performance evaluation

This study focuses on the comparative modeling and refueling simulations of hydrogen refueling stations for hydrogen-powered vehicles and high-pressure hydrogen storage options in tanks. The study further aims to simulate these under actual conditions in Ontario, Canada for better assessment which can be treated as a case study as well. The specific tests explore the modeling of hydrogen flow between the recharging station to the car's tank, as well as the optimization of transient variations in temperature, pressure and mass flow rate of hydrogen throughout the process of refueling a fuel cell electric vehicle. The H2FILLS program is utilized to assist for the simulation studies. The primary objective is to replicate various practical weather conditions, tank pressures, flow rates, and refueling periods for different categories of high-pressure hydrogen storage tanks and analyze their storage efficiency. The three different commercially available high-pressure type-IV hydrogen storage tanks were considered in the study as tank-I, tank-II and tank-III with working pressures of 500 bar, 700 bar, 700 bar, and hydrogen storage capacity of 9.5 kg, 4.6 kg, and 5 kg, respectively. Seven different ambient temperatures were selected to mimic seasonal effects. When the power output is constant, with temperature increases, flow rate decreases, and therefore time required to refuel also increases. There is a linear relationship between the final mass flow rate and the ambient temperature, where the mass flow rate drops by approximately 1.8 kg/h for every 10 °C rise in temperature. The variation in ultimate mass flow rate between the highest and lowest ambient temperatures is roughly 5.4 kg/h. Based on the refueling time and docking, undocking, downtime it’s been found that approximately five minutes is wasted between each vehicle. This can help reduce average of 230.02 kt, 231.70 kt, and 235.06 kt CO2 emission per year for vehicle-III, vehicle-II, and vehicle-I, respectively. Lastly, yearly CO2 reduction forecast shows that it may reach 0.9 Mt, 1.6 Mt, 2.7Mt, 3.76 Mt, and 4.73 Mt in the year 2030, 2035, 2040, 2045, and 2050, respectively corresponding to the Global Net-Zero scenario.

Molecular investigation on physical and tensile properties of polyethylene (PE) under high-pressure hydrogen environments

Polymer liners are key components of high-pressure hydrogen storage tanks, and understanding their behaviour under such environments is crucial for safety. This study employs molecular dynamics (MD) simulation to investigate the physical and tensile properties of amorphous polyethylene (PE) under the effects of hydrogen content, pressure, temperature. It is found that hydrogen molecules decrease glass transition temperature by approximately 3%, while pressure have no noticeable impact. Meanwhile, hydrogen molecules enhance diffusivity, while pressure suppresses diffusivity and exhibits a more pronounced impact, resulting in an overall decrease of 44% in diffusivity under high-pressure hydrogen. Tensile stress also increases the diffusivity by 17%. Hydrogen molecules weaken the non-bonded molecular interactions of PE, which reduces the percentage of trans conformation and orientation parameters. Meanwhile, hydrogen also suppresses the internal energy change of PE induced by tensile deformation. Therefore, hydrogen molecules lead to a decrease in tensile properties. Comparatively, pressure causes PE to produce more trans conformations under tension, which improves orientation, entanglement parameters, and the internal energy change of PE, and finally enhances the tensile properties of PE. The effect of pressure surpasses that of hydrogen, which results in an approximately 40% increase in tensile properties under high-pressure hydrogen. This study provides molecular-level insights into the individual and coupled effects of hydrogen and pressure, forming a foundation for predicting polymer behaviour under high-pressure hydrogen conditions.

Effects of hydrogen cycling on the performance of 70 MPa high-pressure hydrogen storage tank liners formed by different processes

Current research on the compatibility between plastic liners utilized in Type IV high-pressure hydrogen storage containers and hydrogen remains insufficiently comprehensive. Therefore, further exploration into how the high-pressure hydrogen storage process influences the crystalline phase transition of polymers is essential to improve the applicability and safety of plastic lining materials. This study primarily investigated the preparation of polyamide 1012 (PA1012) and polyamide 11 (PA11) through rotational molding and injection molding, denoted as Roto-PA1012/Roto-PA11 and In-PA1012/In-PA11, respectively. Considering the operational parameters of the 70 MPa Type IV hydrogen storage tank, we conducted hydrogen cycling experiment using the long carbon chain polyamide (LCPA) liner materials and comprehensively analyzed the morphology, crystal structure, grain size, mechanical properties and hydrogen barrier properties of polyamide materials before and after hydrogen cycling. The results showed that after hydrogen cycling, no significant changes were observed in Roto-PA1012/Roto-PA11, while In-PA1012/In-PA11 demonstrated severe foaming. Rotational molding of LCPA maintained stable mechanical and hydrogen barrier properties throughout the hydrogen cycle, which can be attributed to the favorable thermodynamic stability of the α' form achieved during rotational molding, leading to uniform and stable crystal sizes. In conclusion, this study provides a theoretical foundation for future investigations into the molding process and material selection of high-barrier polymer liners, as well as the actual production and utilization of Type IV hydrogen storage tanks.

Release of high-pressure hydrogen from type III tank in a fire scenario: Analysis and prediction of jet flame length and thermal response characteristics

In this paper, the thermal response and jet flame behaviour of a typical type III high-pressure hydrogen storage tank with nominal working pressure (NWP) and volume of 70 MPa and 48 L were analysed at fire scenarios. The tank was discharged at a critical internal pressure 77.4 MPa, which was ca. 110 % of NWP. The pressure drop rates of type III tanks were greater than 1 MPa/s during the initial 15 s after venting. The length and width of jet flame were 4.93 and 1.65 m at the critical moment, which fluctuated downward over time. A thermokinetic model was employed to predict the variation of hydrogen gas state parameters and the maximum length of jet flame. The calculation results indicated that the maximum flame length of hydrogen released from a valve of 2 mm was around 2–6.5 m under a pressure range of 10–80 MPa. The error between the predicted results and the experimental values was less than 5 %. It was found that the flame length was enlarged by an increase of aperture. The length of flame increased by 6 m after the aperture changed from 2 to 5.08 mm at the equivalent pressure.

Techno-economic feasibility of integrating hybrid battery-hydrogen energy storage system into an academic building

Green hydrogen production and storage are vital in mitigating carbon emissions and sustainable transition. However, the high investment cost and management requirements are the bottleneck of utilizing hybrid hydrogen-based systems in microgrids. Given the necessity of cost-effective and optimal design of these systems, the present study examines techno-economic feasibility of integrating hybrid hydrogen-based systems into an outdoor test facility. With this perspective, several solar-driven hybrid scenarios are introduced at two energy storage levels, namely the battery and hydrogen energy storage systems, including the high-pressure gaseous hydrogen and metal hydride storage tanks. Dynamic simulations are carried out to address subtle interactions in components of the hybrid system by establishing a TRNSYS model coupled to a Fortran code simulating the metal hydride storage system. The OpenStudio-EnergyPlus plugin is used to simulate the building load, validate against experimental data, according to the measured data and monitored operating conditions. Aimed at enabling efficient integration of energy storage systems, a techno-enviro-economic optimization algorithm is developed to simultaneously minimize the levelized cost of the electricity and maximize the CO2 mitigation in each proposed hybrid scenario. The results indicate that integrating the gaseous hydrogen and metal hydride storages into the photovoltaic-alone scenario enhances 22.6% and 14.4% of the annual renewable factor. Accordingly, the inclusion of battery system to these hybrid scenarios gives a 30.4% and 20.3 % boost to the renewable factor value, respectively. Although the inclusion of battery energy storage into the hybrid systems increases the renewable factor, the results imply that it reduces the hydrogen production rate via electrolysis. The optimized values of the levelized cost of electricity and CO2 emission for different scenarios vary in the range of 0.376–0.789 $/kWh and 6.57–9.75 ton, respectively. The multi-criteria optimizations improve the levelized cost of electricity and CO2 emission by up to 46.2% and 11.3%, with respect to their preliminary design.

Research on active and passive schemes for safety improvement of nuclear energy hydrogen production system

Nuclear hydrogen production has the advantages of large-scale and low carbon emissions, and is expected to play an active role in the energy transition process. However, the storage and transportation of hydrogen pose potential risks of leakage and diffusion when connected to high-pressure hydrogen storage tanks and pipelines. To address this concern, this study focused on designing three distinct safety improvement schemes tailored for potential hydrogen leakage accidents. These schemes encompassed a passively distributed arrangement of obstacles (Scheme 1), a passively centralized arrangement of obstacles (Scheme 2), and an active fan array blowing (Scheme 3). Numerical simulation methods were applied on extensive spatial scales for relevant calculations. The results revealed that all three schemes effectively reduced the diffusion distance of combustible hydrogen. Specifically, at lower ambient wind speeds, Scheme 1, Scheme 2, and Scheme 3 achieved the shortest diffusion distances of 123 m, 56 m, and 46 m, respectively. Meanwhile, at higher ambient wind speeds, the corresponding distances were 282 m, 100 m, and 79 m. These results collectively offer valuable insights to mitigate the risk of leakage accidents in nuclear hydrogen production systems.

An Integrated Risk Assessment Methodology of In-Service Hydrogen Storage Tanks Based on Connection Coefficient Algorithms and Quintuple Subtraction Set Pair Potential

At present, there have been a number of hydrogen storage tank explosions in hydrogen filling stations, causing casualties and property losses, and having a bad social impact. This has made people realize that the risk assessment and preventive maintenance of hydrogen storage tanks are crucial. Therefore, this paper innovatively proposes a comprehensive risk assessment model based on connection coefficient algorithms and quintuple subtractive set pair potential. First of all, the constructed index system contains five aspects of corrosion factors, material factors, environmental factors, institutional factors and human factors. Secondly, a combined weighting analysis method based on FAHP and CRITIC is proposed to determine the weight of each indicator. The basic indicators influencing hydrogen storage tanks are analyzed via the quintuple subtraction set pair potential and full partial connection coefficient. Finally, the risk level and development trend of hydrogen storage tanks in hydrogen filling stations are determined by a combination of the three-category connection coefficient algorithms and the risk level eigenvalue method. The results of our case analysis show that the proposed risk assessment model can identify the main weak indicators affecting the safety of hydrogen storage tanks, including installation quality, misoperation and material quality. At the same time, it is found that the risk of high-pressure hydrogen storage tanks is at the basic safety level, and the development trend of safety conditions holds a critical value. The evaluation results can help establish targeted countermeasures for the prevention and maintenance of hydrogen storage tanks.

Modeling and Simulation of a Renewable Energy PV/PEM with Green Hydrogen Storage

The introduction of green hydrogen-based energy storage in association with renewable energy constitutes a promising and sustainable solution to the increase in energy demand while reducing greenhouse gas emissions. However, these hybrid systems face technical, economic, and logistic challenges that require a new transport and distribution architecture. The technical-economic study of these expensive installations requires good modeling and optimal sizing of the system components. This study presents a global model for hydrogen production and storage stations using photovoltaics (PV) and integrating Proton Exchange Membrane Fuel Cell (PEMFC) modules for electric vehicles. The simulations and sizing were based on the implementation of an effective mathematical model capable of accurately simulating the real dynamic behavior of the installation, the electrical and energy yields, the power consumed and produced, and finally the mass of hydrogen stored and/or consumed by the fuel cell. In this model, the hybrid system integrates PV solar panels with a maximum power of 1.2 MW, followed by a 1.0 MW Proton Exchange Membrane (PEM) electrolyzer, a high-pressure hydrogen storage tank, and a PEMFC to convert hydrogen into electricity. The simulation results showed that the energy generated by the PV panels can produce around 200 kg/day of green hydrogen by electrolysis, which makes it possible to power 100 electric cars per day with a range of 250 km for each.

Numerical investigation on the influence of geometrical parameters on the temperature distribution in marine hydrogen storage tanks during filling

This paper established a two-dimensional axisymmetric model with a marine high-pressure hydrogen storage tank as the research object. Using numerical simulation, the effects of different aspect ratios, inlet diameters, and inlet pipe lengths on the temperature rise of the hydrogen storage tank during the filling process were studied. As the L/D ratio of the hydrogen storage tank increases, the momentum of the hydrogen gas reaching the bottom of the tank gradually decreases, making it easier to form localized high-temperature regions. For a hydrogen storage tank with an L/D of 6.0, the difference between the maximum and average temperature at the end of filling was 155.85 K. In contrast, the temperature difference of the tank with an L/D of 3.6 was only 32.81 K. In addition, the inlet pipe delivers the hydrogen deep into the tank and reduces the obstructing effect of the existing hydrogen in the tank on the newly filled hydrogen. For smaller L/D hydrogen storage tanks, the inlet pipe may backfire and create a high-temperature zone at the shoulder of the tank. In contrast, for larger L/D hydrogen storage tanks, a suitable length of inlet pipe can deliver the hydrogen deep into the tank. This will enhance the gas flow inside the tank, facilitating heat exchange and avoiding the formation of localized high-temperature areas at the bottom of the tank. However, excessively long inlet pipes can also lead to high-temperature areas on the shoulders. At a specific charge mass flow rate, the lower the inlet diameter, the higher the hydrogen flow rate. The larger flow rate helped promote uniform hydrogen mixing in the tank and made it challenging to form localized high-temperature regions.

Computational study of a high-pressure hydrogen storage tank explosion at different heights from the ground

A computational study was carried out to investigate the explosion of a 35-MPa, 72.4-L high-pressure hydrogen storage tank at different heights from the ground. The numerical simulations were carried out using OpenFOAM computational fluid dynamics code. The numerical simulation incorporates a k−ω shear stress transport turbulence model and an eddy dissipation concept combustion model with a one-step finite rate reaction. The prediction performance of the numerical approach was validated based on experimental results obtained from previous studies. The hydrogen tank explosion was investigated at different heights (h; 0.0, 0.2, 0.5, 0.8, and 1.0 m) from the ground and at h = 0.2 m from the ground with θ = 65°). The numerical predictions showed that tank height and position significantly affect the blast overpressure strength and propagation. The reflected pressure magnitude increased as the tank height decreased with respect to ground level. At farther distances, the explosion scenario of h = 0.2 m and θ = 65° showed stronger maximum overpressure and impulse hazards than the other height settings. The difference in maximum overpressure magnitude between the different explosion scenarios was insignificant at 4 m from the tank. Hydrogen gas auto-ignites closer to the ground, due to the compression effect attributed to the Mach stem phenomenon. Our results showed that blast effects in the radial direction are more hazardous than those in the axial direction.

Explosion of high pressure hydrogen tank in fire: Mechanism, criterion, and consequence assessment

This study published experimental data on the catastrophic rupture consequences of high-pressure hydrogen storage tanks in fire environments. It made up for the lack of actual explosion data for verification of the traditional theoretical prediction models and numerical simulations. To reveal the mechanism of high-pressure tank explosion and corresponding characteristics of hydrogen explosion, the fireball parameters, fragment characteristics, and blast wave attenuation patterns resulting from tank rupture were analyzed. The results indicated that the hazard of hydrogen storage tank explosion was coupled with the combined contribution of physical and chemical explosion energies. The failure pressure of a 6.8 L – 30 MPa tank under fire conditions decreased by 60.3 % compared to that at room temperature. Following tank explosion, the duration of hydrogen-air deflagration was only about 2 s, and the maximum diameter of the fireball was nearly 4.48 m. A portion of the mechanical energy generated by tank explosion was converted into the kinetic energy of projectile fragments, with the farthest discovered fragment distance reaching 46.0 m. Additionally, the measured peak overpressure decreased from 875.33 kPa to 7.52 kPa at distances ranging from 2 m to 15 m from the explosion source. To evaluate blast wave overpressure in high-pressure hydrogen tanks for engineering applications, a standardized and generalized procedure was innovatively proposed, and its effectiveness was validated by experimental data. Furthermore, the hazardous distances defined by the peak overpressure were utilized to delineate risk zones. The distances of 61.6 m and 17.3 m from the explosion source were identified as zones without injury to human and without damage to structures, respectively. The proposed methodology and the results of the experiments were of practical importance for ensuring the safety of high-pressure hydrogen storage systems in various applications.

A contribution to structural reliability analysis of composite high-pressure hydrogen storage tanks

Although composite high-pressure tanks are a subject of growing interest, especially for hydrogen storage applications, a detailed structural reliability analysis still needs to be improved. This work aims to provide a probabilistic investigation of the mechanical response of composite high-pressure hydrogen storage tanks using the Monte Carlo Simulation method. A performance function based on the circumferential model of composite pressure cylinders is employed with five random design variables. According to the results, the internal pressure and the helical layer thickness are the foremost parameters significantly impacting the structural reliability of the tank, whereas, the helical layer thickness and winding angles have a minor influence. In addition, high coefficients of variation values cause the contraction of the safety margin potentially leading to the failure of the composite hydrogen high-pressure tank. The obtained results were validated with experimental tests available in the literature

Numerical simulation of hydrogen explosion characteristics and disaster effects of hydrogen fueling station

As the foundation for the growth of the hydrogen energy industry and hydrogen energy automobile, hydrogen fueling stations have emerged as the top priority for industrial development in the context of green transformation. However, the high risk of hydrogen and the increasing hydrogen storage pressure in the station make it easy to cause catastrophic explosion mishaps once hydrogen leaks. Therefore, based on the actual layout of construction and facilities dimensions of the Beijing Yongfeng hydrogen fueling station, we studied the propagation law of the hydrogen explosion shock wave in the station under various conditions and analyzed the structural dynamic response process of surrounding structures under the action of the explosion shock wave. Finally, we visualized and quantitatively evaluated the consequences of a hydrogen explosion in the station by establishing a risk matrix and an accident consequence level matrix.The results show that a hydrogen explosion's consequence severity is influenced by the ambient temperature, ignition source form, and the instantaneous concentration of the hydrogen cloud at the ignition. Following a hydrogen explosion at a high-pressure hydrogen storage tank, the explosion-proof wall failed and collapsed under the shock wave action, but the high-pressure hydrogen storage tank and the hydrogen long tube trailer storage tank did not fail and rupture. Additionally, the probability of hydrogen leakage and explosion accidents at the high-pressure storage tank of the Yongfeng hydrogen fueling station is level 3. The high-risk area of the station for personnel injury accounts for 1/5 of the station area; the medium-risk area accounts for 4/25, and the rest is a low-risk area. Moreover, the high-risk area of the station for construction damage accounts for 1/25 of the station area; the medium-risk area accounts for 4/25, and the rest is a low-risk area.

Ultimate pressure-bearing capacity of Type III onboard high-pressure hydrogen storage tanks under typical accident scenarios

Sufficient pressure-bearing performance was the basis for ensuring the safety of hydrogen storage tanks in service for the entire life cycle. The aim of this study was to analyze the ultimate pressure-bearing capacity of tanks under possible working conditions, such as room temperature, fire, and after flame exposure. The results show that the actual burst pressure of a Type III tank of 48 L and 70 MPa at room temperature was 209.80 MPa, which had sufficient explosion-proof behavior. Compared with the room temperature, the critical failure pressure of the tank under fire conditions dropped sharply by ca. 63.1 %, which readily induced pressure-bearing failure. However, after cooling to room temperature, the residual burst pressure of the tank thermally damaged by fire was only roughly 14.5 % lower than the ultimate pressure-bearing pressure at room temperature, and still maintained a certain strength. The grey correlation analysis model of influencing factors on the ultimate pressure-bearing performance of tanks in normal temperature and fire environments was established for the first time. This paper reports quantitatively that, in addition to the nominal working pressure, the design wall thickness of the tank at room temperature has the most prominent effect on the pressure-bearing performance. While the initial filling pressure and flame exposure time in fire environments were considered to be the key factors affecting the pressure bearing performance.

Modeling and Simulation of Hydrogen Energy Storage System for Power-to-gas and Gas-to-power Systems

By collecting and organizing historical data and typical model characteristics, hydrogen energy storage system (HESS)-based power-to-gas (P2G) and gas-to-power systems are developed using Simulink. The energy transfer mechanisms and numerical modeling methods of the proposed systems are studied in detail. The proposed integrated HESS model covers the following system components: alkaline electrolyzer (AE), high-pressure hydrogen storage tank with compressor (CM & H2 tank), and proton-exchange membrane fuel cell (PEMFC) stack. The unit models in the HESS are established based on typical U-I curves and equivalent circuit models, which are used to analyze the operating characteristics and charging/discharging behaviors of a typical AE, an ideal CM & H2 tank, and a PEMFC stack. The validities of these models are simulated and verified in the MicroGrid system, which is equipped with a wind power generation system, a photovoltaic power generation system, and an auxiliary battery energy storage system (BESS) unit. Simulation results in MATLAB/Simulink show that electrolyzer stack, fuel cell stack and system integration model can operate in different cases. By testing the simulation results of the HESS under different working conditions, the hydrogen production flow, stack voltage, state of charge (SOC) of the BESS, state of hydrogen pressure (SOHP) of the HESS, and HESS energy flow paths are analyzed. The simulation results are consistent with expectations, showing that the integrated HESS model can effectively absorb wind and photovoltaic power. As the wind and photovoltaic power generations increase, the HESS current increases, thereby increasing the amount of hydrogen production to absorb the surplus power. The results show that the HESS responds faster than the traditional BESS in the microgrid, providing a solid theoretical foundation for later wind-photovoltaic-HESS-BESS integration.

Rethinking “BLEVE explosion” after liquid hydrogen storage tank rupture in a fire

The underlying physical mechanisms leading to the generation of blast waves after liquid hydrogen (LH2) storage tank rupture in a fire are not yet fully understood. This makes it difficult to develop predictive models and validate them against a very limited number of experiments. This study aims at the development of a CFD model able to predict maximum pressure in the blast wave after the LH2 storage tank rupture in a fire. The performed critical review of previous works and the thorough numerical analysis of BMW experiments (LH2 storage pressure in the range 2.0–11.3 bar abs) allowed us to conclude that the maximum pressure in the blast wave is generated by gaseous phase starting shock enhanced by combustion reaction of hydrogen at the contact surface with heated by the shock air. The boiling liquid expanding vapour explosion (BLEVE) pressure peak follows the gaseous phase blast and is smaller in amplitude. The CFD model validated recently against high-pressure hydrogen storage tank rupture in fire experiments is essentially updated in this study to account for cryogenic conditions of LH2 storage. The simulation results provided insight into the blast wave and combustion dynamics, demonstrating that combustion at the contact surface contributes significantly to the generated blast wave, increasing the overpressure at 3 m from the tank up to 5 times. The developed CFD model can be used as a contemporary tool for hydrogen safety engineering, e.g. for assessment of hazard distances from LH2 storage.

Influence of obstacle morphology on safety of nuclear hydrogen production system

The safety of the nuclear hydrogen production system is a key issue that cannot be ignored in the future commercialization. The reasonable arrangement of obstacles can effectively improve the safety of the system under accident conditions. In this paper, based on the high-pressure hydrogen storage tank model of a nuclear hydrogenation plant, two mechanisms by which obstacles can effectively improve safety are analyzed. In order to determine the obstacle design scheme with outstanding effect, the response surface methodology is used to study the influence of the structural parameters and spatial position parameters of obstacles of different shapes, and the comprehensive performance of different obstacles is compared by the TNO multi-energy method. The results show that the semi-cylindrical surface can control the separation distance within 141 m at a lower processing cost, which has good engineering utilization value. This study can provide a valuable reference for the design of nuclear hydrogen production systems.

Study on hazards from high-pressure on-board type III hydrogen tank in fire scenario: Consequences and response behaviours

Exploration of thermal performances of composite high-pressure hydrogen storage tank under fire exposure were critical issues to reduce the risk of tank rupture. Three bonfire tests of type III tanks of 210 L-35 MPa with full compressed hydrogen were exposed to a pool fire to study the response behaviours in fire scenarios. Detailed data on the tank wall temperature and inner pressure were presented in this work. Prototype bonfire tests for the type III tank indicated the failure pressure limits amounted to 41.1–41.8 MPa (average 41.4 MPa). Two consequences (rupture and hydrogen blowdown) will be caused when the inner pressure beyond this limits in fire scenario. The loading-bearing capacity of the tank reduced nearly 3 times under the prescribed fire condition when compared to its average burst pressure of 123.5 MPa conducted from the hydraulic burst test. Results also shown that fire resistance rating (FRR, time to rupture) of the three tanks were 784, 666, and 596, respectively. The FRR got shorter when the tank was exposed in the engulfing fire in advance at hydrogen blowdown case.

The design and optimization of a cryogenic compressed hydrogen refueling process

Cryo-compressed hydrogen storage has excellent volume and mass hydrogen storage density, which is the most likely way to meet the storage requirements proposed by United States Department of Energy（DOE）. This paper contributes to propose and analyze a new cryogenic compressed hydrogen refueling station. The new type of low temperature and high-pressure hydrogenation station system can effectively reduce the problems such as too high liquefaction work when using liquid hydrogen as the gas source, the need to heat and regenerate to release hydrogen, and the damage of thermal stress on the storage tank during the filling process, so as to reduce the release of hydrogen and ensure the non-destructive filling of hydrogen. This paper focuses on the study of precooling process in filling. By establishing a heat transfer model, the dynamic trend of tank temperature with time in the precooling process of low-temperature and high-pressure hydrogen storage tank under constant pressure is studied. Two analysis methods are used to provide theoretical basis for the selection of inlet diameter of hydrogen storage tank. Through comparative analysis of the advantages and disadvantages of the two analysis methods, it is concluded that the analysis method of constant mass flow is more suitable for the selection in practical applications. According to it, the recommended diameter of the storage tank at the initial temperature of 300 K, 200 K and 100 K is selected, which are all 15 mm. It is further proved that the calculation method can meet the different storage tank states of hydrogen fuel cell vehicles when selecting the pipe diameter.