Hydrogen Tank Research Articles

Optimized Design of a H2-Powered Moped for Urban Mobility

Micro-mobility plays an increasingly important role in the current energy transition thanks to its low energy consumption and reduced contribution to urban congestion. In this scenario, fuel cell hybrid electric vehicles have several advantages over state-of-the-art battery electric vehicles, such as increased driving ranges and reduced recharge times. In this paper, we study the conversion of a commercial electric moped (Askoll eS3®) into a fuel cell hybrid electric vehicle by finding the optimal design of the components through an optimization methodology based on backward dynamic programming. This optimal design and operation strategy can also be implemented with a rules-based approach. The results show that a system composed of a 1 kW proton exchange membrane fuel cell, a 2000 Sl metal hydride hydrogen tank, and a 240 Wh buffer battery can cover the same driving range as the batteries in an electric moped (119 km). Such a hybrid system occupies considerably less volume (almost 40 L) and has a negligibly higher mass. The free volume can be used to extend the driving range up to almost three times the nominal value. Moreover, by using a high-pressure composite tank, it is possible to increase the mass energy density of the onboard energy storage (although compression can require up to 10% of the hydrogen’s chemical energy). The fuel cell hybrid electric vehicle can be recharged with green hydrogen that is locally produced. In detail, we analyze a residential scenario and a shared mobility scenario in the small Italian city of Viterbo.

Generalized thermodynamic modeling of hydrogen storage tanks for truck application

Hydrogen-driven heavy-duty trucks are a promising technology for reducing CO2 emissions in the transportation sector. Thus, storing hydrogen efficiently onboard is vital. The three available or currently developed physical hydrogen storage technologies (compressed gaseous, subcooled liquid, and cryo-compressed hydrogen) are promising solutions. For a profound thermodynamic comparison of these storage systems, a universally applicable model is required. Thus, this article introduces a generalized thermodynamic model and conducts thermodynamic comparisons in terms of typical drive cycle scenarios. Therefore, a model introduced by Hamacher et al. [1] for cryo-compressed hydrogen tanks is generalized by means of an explicit model formulation using the property cv2P from REFPROP [2], which is understood as a generic specific isochoric two-phase heat capacity. Due to an implemented decision logic, minor changes to the equation system are automatically made whenever the operation mode or phase of the tank changes. The resulting model can simulate all three storage tank systems in all operating scenarios and conditions in the single- and two-phase region. Additionally, the explicit model formulation provides deeper insights into the thermodynamic processes in the tank. The model is applied to the three physical hydrogen storage technologies to compare drive cycles, heat requirement, dormancy behavior, and optimal usable density. The highest driving ranges were achieved with cryo-compressed hydrogen, however, it also comes with higher heating requirements compared to subcooled liquid hydrogen.

Hydrogen fuel cell aircraft for the Nordic market

A model for a fuel cell propelled 50 PAX hydrogen aircraft is developed. In terms of year 2045 Nordic air travel demand this aircraft is expected to cover 97% of travel distances and 58% of daily passenger volume. Using an ATR 42 as a baseline, cryogenic tanks and fuel cell stacks are sized and propulsion system masses updated. Fuselage and wing resizing are required, which increases mass and wetted area. Sizing methods for the multi-stack fuel cell and the cryogenic tanks are implemented. The dynamic aircraft model is updated with models for hydrogen consumption and tank pressure control. For the Multi-layer insulation (MLI) tank a trade study is performed. A ventilation pressure of 1.76 bar and 15 MLI layers are found to be optimal for the design mission. A return-without-refuel mission is explored, where for a 10-hour ground hold 38.4% of the design range is retained out of the theoretically achievable 50%.

Computational design of vapor-cooled shield structure for liquid hydrogen storage tank

Computational design of vapor-cooled shield structure for liquid hydrogen storage tank

Structural sizing of a hydrogen tank for a commercial aircraft

To respond to the current climate crisis, hydrogen-powered aircraft are seen as a promising solution in the aviation sector to cut down CO 2 emissions. Hydrogen-fueled aircraft present however huge challenges, especially due to the complex storage of hydrogen. To achieve a reasonable fuel energy density for medium- to long-range missions, hydrogen must indeed be stored in liquid form in big and heavy pressurized tanks. Tank design must so be included in conceptual design, which now has an important impact on the aircraft. This study proposes a structural sizing methodology for a liquid hydrogen tank for a commercial aircraft. A parametric model of a cylindrical cryogenic tank placed at the back of the cabin in a conventional aircraft is created and sized to withstand pressure, bending, torsion and shear loads. The process integrates sizing standards for pressurized structures of the current CS-25 regulation in its methodology and remains general enough to consider both integral and non-integral tanks of any dimensions or materials. Initial analyses show a clear dependency of the tank’s performance as well as the optimal stiffening structure configuration on the design pressure.

Non-Destructive Testing of Laser Welded Hydrogen Storage Tank Liner Using Optical Coherence Tomography

The Type 4 hydrogen storage tank has an internal liner made of polymer material. Instead of the joining of two cylinder-shaped liners through butt-joint thermal fusion bonding, a faster joining can be achieved through lap-joint laser welding. Non-destructive testing is required to inspect the quality of laser-welded areas and to detect pore defects. In this study, the interface of a laser-welded region is investigated using optical coherence tomography to detect internal pore defects, where the maximum thickness of the liner is found to be approximately 3 mm. Optical coherence tomography images with defects are then used for supervised YOLOv2 deep learning. Real-time detection of internal defects is successfully performed on laser-welded liner samples.

Investigation of a tri-renewable energy system coupled with battery and hydrogen storages for a sustainable city

A novel integrated energy system, where tri-renewable energy sources are coupled with a battery and hydrogen storage system, is proposed. The objective of this paper is then to investigate and evaluate the overall system thermodynamically for potential applications. Solar, biomass and wind energy sources are considered in the system development, and the potential needs of the community including electricity, heat, and hot water are fulfilled. A fraction of the renewable solar energy is stored in the form of hydrogen to operate the system during the off-peak time. The stored hydrogen is then employed to operate a proton exchange membrane (PEM) fuel cell, and electrical energy is produced for the charging station. Several sensitivity analyses are performed to demonstrate the effectiveness and feasibility of the H2 storage system. The share of H2 power to power (P2P) solution increases from 18.5 % at a photovoltaic (PV) area of 250 m2 to 45.4 % at a PV area of 500 m2. During the charging mode, around 25.5 MWh of excess solar energy is generated from the PV field. The deployment of 500 m2 can generate 769 kg of hydrogen that is stored in the hydrogen storage tank, and it can generate 18.4 MWh of energy from the PEM fuel cell. The calculated hydrogen storage results demonstrate a competitive round-trip efficiency of around 45.5 %.

Combining fuzzy MCDM with Kano model and FMEA: a novel 3-phase MCDM method for reliable assessment

In the circular economy era, this study addresses sustainable business management for high-investment and long-life cycle projects, where accurate and reliable assessments are crucial to ensuring successful outcomes. The objective is to elevate the reliability of assessments by introducing a novel decision-making method that, for the first time, integrates time-based satisfaction and risk factors simultaneously. We propose a 3-phase multi-criteria decision-making (MCDM) method, which combines fuzzy MCDM comprising fuzzy analytic hierarchy process and fuzzy technique for order preference by similarity to ideal situation (TOPSIS), Kano model, and failure mode and effects analysis (FMEA) techniques, to handle reliable assessments effectively. Our method is distinct in its incorporation of time-based satisfaction weights derived from Kano model, emphasising decision-makers’ criteria preferences in short, medium, and long terms. Furthermore, we introduce risk-discounted weights by using FMEA to tune criteria scores. The method is validated via a numerical example case, assessing and selecting the most appropriate hydrogen storage method for lightweight vehicles. The results suggest that cryo-compressed hydrogen tank with 250–350 bar and at cryogenic temperature is the most suitable storage method. Health & safety with a weight of 0.5318 emerges as the most important main criterion, and permeation & leakage with a weight of 0.4008 is the most important sub-criterion. To bridge the gap between theoretical research and practical application, we transform the new method into a user-friendly web application with graphical user interface (GUI). End-users can conduct reliable assessments and foster sustainable business management through informed decision-making.

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.

Surface Polishing of an Inconel 625 Bar by a Super-Fast MAF Process for a Solenoid Valve Stem Used in a Hydrogen Tank

This study explores a super-fast magnetic abrasive finishing (MAF) process for polishing the surface of an Inconel 625 bar workpiece for a hydrogen solenoid valve stem. The Inconel 625 bar was chosen to replace the existing STS 316 bar material, previously used for a hydrogen solenoid valve stem. The cylindrical surface of Inconel 625 bars was polished by a super-fast MAF process with high rotational speeds of 1000, 5000, 15,000, and 25,000 RPM and a super-strong magnetic field of 550 mT. The polishing characteristics of this process were evaluated according to the type of abrasives, rotational speeds of the workpiece and processing time. As a result, a super-smooth Inconel 625 bar was successfully achieved, with a surface roughness (Ra) reduced from 0.31 μm to 0.02 μm under the optimal conditions (15,000 RPM, CNT particles (0.04 μm), PCD diamond abrasive (1 μm), Fe (#200), 0.5 g of light oil, and 16 min of processing time). Also, the Ansys analysis results showed suitable strain, equivalent stress, and safety factor of the Inconel 625 bar. This confirmed that, after a super-fast MAF process, an Inconel 625 bar is feasible for application in Hydrogen (H2) tanks instead of a conventional STS 316 bar.

Research on hydrogen leakage and diffusion mechanism in hydrogenation station

As a clean, efficient and sustainable energy carrier, hydrogen energy has been accepted as one of the main directions of future energy development. In this paper, a hydrogenation station providing compressed hydrogen outside was adopted as the research object. Based on finite element method and virtual nozzle model, the influence of leakage of main equipment in hydrogenation station on the distribution of combustible hydrogen was investigated, including hydrogen storage tank group, tube trailer, compressor chamber and hydrogenator. The results showed that the shape and volume of the combustible hydrogen cloud generated by the leak were influenced by obstacles, hydrogen storage pressure, and wind velocity. The disturbance of external wind and the decrease in hydrogen storage pressure will have a positive impact on the reduction of leaked volume. The diffusion of combustible hydrogen clouds can be exacerbated by complex structure of obstacles, while partition wall in the adopted hydrogenation station model can limit the combustible hydrogen cloud in the process area. These conclusions can provide guidance and reference for the risk prevention measures of hydrogenation station.

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.

Liquid Hydrogen Storage Tank Loading Generation for Civil Aircraft Damage Tolerance Analysis

The study presented is a preliminary approach and a proposal to the derivation of a loading spectrum for fatigue and damage tolerance analysis for civil aviation Liquid Hydrogen storage tanks. It is anticipated for the first generation of LH2 storage tanks for aviation to utilize metallic lightweight materials. Existing solutions are either too structurally heavy or with a short life span, both constraints making them unsuitable for aircraft vehicles were less mass and longevity is of paramount importance. The objective of the work was to provide suggestions for the generation of representative loading spectra for storage tank fatigue and damage tolerance preliminary design analysis and sizing.

Influence of Porous Inserts and Compact Resonators on Onset of Taconis Oscillations

Abstract Taconis oscillations represent excitation of acoustic modes due to large thermal gradients inside narrow tubes penetrating cryogenic vessels from a warm ambient environment. These oscillations are usually harmful, as they may drastically increase heat leakage into cryogenic vessels and result in strong vibrations of measuring instruments. Placing a porous material inside a tube with a goal to increase acoustic damping or attaching a small resonator to the main tube are some of the possible ways to suppress or mitigate Taconis effects. However, when the porous inserts are positioned in locations with large temperature gradients or the resonator parameters are selected incorrectly, these components may augment thermal-to-acoustic energy conversion and enhance Taconis oscillations. A low-amplitude thermoacoustic model has been extended and applied in this study to determine the effects of the insert location and pore radius, as well as the resonator dimensions, on the onset of Taconis phenomena in a hydrogen-filled tube of relevance to lines used in cryogenic hydrogen storage tanks. The presented findings can assist cryogenic specialists interested in suppressing or exciting Taconis oscillations.

Integration of cascaded coordinated rolling horizon control for output power smoothing in islanded wind–solar microgrid with multiple hydrogen storage tanks

This paper presents a strategy based on the hierarchical rolling horizon control, also called model predictive control (MPC), for efficiently managing a hydrogen-energy storage system (HESS) within an islanded wind–solar microgrid. An electrolyzer uses electricity generated from renewable sources to produce clean hydrogen, which is then re-electrified by a fuel cell as needed to meet the microgrid’s loads. The main contribution lies in the incorporation of multiple hydrogen storage tanks in the HESS, distinguishing it from existing literature, which typically focuses on a single tank. The incorporation of multiple tanks in the HESS enables the storage of large volumes of hydrogen for long-term use, allowing the microgrid to operate autonomously without interaction with the utility grid. In order to ensure optimal performance, the selection of the most suitable device for operation at each time-step is crucial. The proposed control strategy takes into account the economic and operational costs, degradation aspects, and physical constraints of the HESS, while simultaneously ensuring the tracking of reference demands and with the highest priority smoothing out the variations of renewable energy sources. Numerical simulations and a lab-scale microgrid setup demonstrate that the controller effectively manages the HESS thus satisfying economic constraints and optimizing device costs, even when deviations occur between the predicted and real-time scenarios. Furthermore, the inclusion of multiple hydrogen tanks allows the microgrid to both mitigate fluctuations in renewable power sources and effectively meet load demand.

Blended Wing Body Configuration for Hydrogen-Powered Aviation

Hydrogen aircraft have the potential to achieve more significant climate impact reductions at a lower cost than aircraft powered by biofuels or other drop-in sustainable aviation fuels. Nevertheless, even as a liquid, hydrogen requires four times more volume than kerosene to store the same energy. Companies and researchers have suggested that the blended wing body configuration is well-suited to hydrogen because it can efficiently store large fuel tanks. However, nobody has quantified this claim, at least publicly. We address this gap by comparing optimized kerosene and hydrogen versions of blended wing body and tube and wing aircraft. Our models predict that, with ambitious hydrogen tank technology assumptions, a hydrogen blended wing body has a 3.8% energy penalty compared to a kerosene blended wing body. In contrast, the energy penalty for a tube and wing is 5.1%. These results suggest that the blended wing body configuration is slightly better suited to hydrogen than a tube and wing. However, the conclusion breaks down under less optimistic scenarios where lightweight conformal liquid hydrogen tanks are unavailable. Nonetheless, the energy penalties of switching the two configurations to hydrogen have a similar order of magnitude. Any kerosene blended wing body fuel burn benefit over a tube and wing also applies to hydrogen versions. As a result, kerosene blended wing body technology developments, such as maturing the structural design of the noncircular pressurized passenger cabin, remain valuable for future hydrogen-powered aircraft.

Numerical study on thermodynamic characteristics of large-scale liquid hydrogen tank with baffles under sloshing conditions

The control of the evaporation rate is essential to the long-distance transportation of liquid hydrogen (LH2). This paper conducts a numerical investigation of the thermodynamic characteristics in tanks with baffles under LH2 sloshing conditions by establishing a computational fluid dynamics (CFD) model. The pressurization rate and vapor-liquid interface sloshing behavior predicted by the numerical model is validated against experimental data. The effects of baffles, amplitude, frequency, and storage pressure on thermodynamic characteristics such as temperature, pressurization rate, and evaporation rate of the LH2 tank under sinusoidal sloshing are analyzed in detail. The simulation results suggest that adding baffles can effectively suppress the pressure fluctuation of LH2 under sloshing conditions, but baffles as a "thermal bridge" accelerate the pressurization rate in the tank. Adding baffles during smooth transportation accelerates the pressurization rate. The baffles gradually demonstrate the effect of suppressing the pressurization rate as the acceleration amplitude increases. Assuming that the LH2 evaporation rate is stable for a certain value, the daily evaporation rates in the LH2 tank account for 2.59 % and 5.13 % when the maximum acceleration is 5.92 m/s2 and 9.87 m/s2, respectively, which contradicts the long-term storage goal of LH2. The slower the sloshing frequency, the higher the maximum liquid phase level in the tank, and the faster the evaporation rate. The sloshing frequency has little effect on the LH2 pressurization and evaporation rates compared to the amplitude. The growth of pressure decreases from 139.9 Pa to 85.62 Pa for a period of 15 s when the storage pressure in the tank increases from 0.1 MPa to 0.6 MPa. This study provides guidlines for the in-depth investigation of the thermodynamic behavior in LH2 tanks during transportation.

Key technology and application of AB2 hydrogen storage alloy in fuel cell hydrogen supply system

At present, there is limited research on the application of fuel cell power generation system technology using solid hydrogen storage materials, especially in hydrogen-assisted two-wheelers. Considering the disadvantages of low hydrogen storage capacity and poor kinetics of hydrogen storage materials, our primary focus is to achieve smooth hydrogen ab-/desorption over a wide temperature range to meet the requirements of fuel cells and their integrated power generation systems. In this paper, the Ti0.9Zr0.1Mn1.45V0.4Fe0.15 hydrogen storage alloy was successfully prepared by arc melting. The maximum hydrogen storage capacity reaches 1.89 ​wt% at 318 ​K. The alloy has the capability to absorb 90% of hydrogen storage capacity within 50 ​s at 7 ​MPa and release 90% of hydrogen within 220 ​s. Comsol Multiphysics 6.0 software was used to simulate the hydrogen ab-/desorption processes of the tank. The flow rate of cooling water during hydrogen absorption varied in a gradient of (0.02 ​+ ​x) m s−1 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1, 0.12). Cooling water flow rate is positively correlated with the hydrogen absorption rate but negatively correlated with the cost. When the cooling rate is 0.06 m s−1, both simulation and experimentation have shown that the hydrogen storage tank is capable of steady hydrogen desorption for over 6 h at a flow rate of 2 L min−1. Based on the above conclusions, we have successfully developed a hydrogen-assisted two-wheeler with a range of 80 km and achieved regional demonstration operations in Changzhou and Shaoguan. This paper highlights the achievements of our team in the technological development of fuel cell power generation systems using solid hydrogen storage materials as hydrogen storage carriers and their application in two-wheelers in recent years.

Enhancing Residential Sustainability: Multi-objective optimization of hydrogen-based multi-energy system

To enhance residential sustainability by providing decarbonized and locally produced energy to a residential district, the relevance of a grid-connected multi-energy system, including PV panels, a battery, an electrolyzer, a hydrogen tank, and a fuel cell, is studied. A model is developed that creates high-resolution, continuous yearly profiles. The model is then utilized in a metaheuristic multi-objective optimization based on total cost and life cycle greenhouse gas emissions to highlight sizing trends. In the results, the most cost-efficient solutions rely mostly on PV power with minimal battery storage capacity, whereas hydrogen systems are necessary to achieve the best emission reductions. The analysis does not identify a promising prospect for seasonal energy storage with the current tank and battery lifetime emissions. Producing more than 65 % of the energy demand locally is not deemed beneficial.

Determination of possible industrial accident effects on a hydrogen storage tank in a fuel cell production facility

Determination of possible industrial accident effects on a hydrogen storage tank in a fuel cell production facility