TY - CONF A1 - Hajhariri, Aliasghar T1 - Enhancing efficiency and safety of LH2 storage for a cleaner future N2 - As the world moves toward decarbonization and a green energy transition, hydrogen is increasingly recognized as a key energy carrier. However, its characteristics include a low volumetric energy density, necessitating storage in a high-density form to enable efficient energy transfer. Liquefied hydrogen (LH₂) offers a solution by providing high gravimetric energy storage within a confined volume. However, cryogenic hydrogen presents significant technical and safety challenges that must be addressed. This presentation explores the safety aspects that impact the integrity of storage systems and provides practical data analysis alongside experimental results, contributing to a broader understanding of liquid hydrogen storage and transportation. T2 - Online Colloquium H2Safety@BAM CY - Berlin, Germany DA - 19.02.2025 KW - Multi-Layer Insulation KW - Cryogenic KW - Liquid Hydrogen KW - Heat transfer PY - 2025 AN - OPUS4-62611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hajhariri, Aliasghar T1 - Steps towards a safe integration of LH2 into energy systems N2 - Liquid hydrogen (LH₂) is a promising energy carrier for decarbonizing heavy-duty transport and future energy systems. However, its cryogenic storage poses significant challenges, particularly regarding safety and insu-lation efficiency. In mobile applications, multilayer insulation (MLI) under vacuum conditions is widely used due to its lightweight and high thermal resistance. Yet, under accidental scenarios such as fire exposure, MLI can degrade rapidly—leading to increased heat ingress and potential hazards like BLEVE or jet fires. To enable the safe integration of LH₂ into transport infrastructure and, eventually, broader energy supply chains, critical safety concerns must be addressed to gain public and industrial acceptance. This study inves-tigates the thermal degradation behavior of MLI under extreme conditions and introduces a model to quan-tify its impact on heat transfer. The results demonstrate that insulation integrity plays a pivotal role in sys-tem safety, and tailored mitigation strategies can be developed accordingly. These findings contribute essen-tial knowledge toward safer LH₂ storage and support the broader adoption of hydrogen as a sustainable energy vector. T2 - DKV-Tagung 2025 CY - Magdeburg, Germany DA - 19.11.2025 KW - Hydrogen Storages KW - Liquid Hydrogen KW - Safety KW - Energy efficiency KW - Process development PY - 2025 AN - OPUS4-64853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hajhariri, Aliasghar T1 - Safer Insulation For LH2 (How to do a Business Development) N2 - To expand the hydrogen supply value chain, the transportation of this highly energy-dense material in its liquid phase presents significant challenges. However, developing an efficient and cost-effective insulation solution can substantially improve the economic feasibility of large-scale hydrogen transport. Such improvements not only enhance the profitability of storing and delivering high energy content within a limited volume, but also strengthen the overall value of the supply chain. Ultimately, this will support more efficient integration of hydrogen into the energy system and improve its economic viability. T2 - Workshop of Entrepreneurship HWR University CY - Berlin, Germany DA - 18.10.2025 KW - Super-Insulation KW - Liquid Hydrogen KW - Safety KW - Supply Chain PY - 2025 AN - OPUS4-64498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hajhariri, Aliasghar T1 - Experimental and Numerical Investigation on Multi-layer Insulation Thermal Deterioration N2 - To reduce carbon dioxide emissions, energy carries such as hydrogen consider to be a solution. Consumption of hydrogen as a fuel meets several restrictions such as its low volumetric energy density in gas phase. To tackle this problem, storage as well as transportation in liquid phase is recommended. To be able to handle this component in liquid phase, an efficient thermal insulation e.g., MLI insulation is required. Some studies have been revealed vulnerability of this type of insulation against high heat flux, for instance a fire accident. Some investigations have been depicted the importance of consideration of the MLI thermal degradation in terms of its reflective layer. However, limited number of studies have been focused on the thermal degradation of spacer material and its effect on the overall heat flux. In this study, through systematic experimental measurements, the effect of thermal loads on glass fleece, glass paper as well as polyester spacers are investigated. The results are reported in various temperature and heat flux profiles. Interpreting the temperature profiles revealed as the number of spacers in the medium increases, the peak temperature detectable by the temperature sensor on the measurement plate decreases. Moreover, the contribution of each individual spacer in all cases regarding the experimental temperature range is assessed to be around 8%. This value may increase to around 50% for glass paper and polyester spacers, and to around 25% for glass fleece spacers as the number of spacer layers increases up to six layers. To utilize the outcomes of the experiment later and integrate the results into numerical and CFD simulations, a model is proposed for the mentioned experimental temperature range up to 300°C to predict a heat flux attenuation factor. The model proposes a fitting factor that can reproduce the least square fitted line to the experimental data. T2 - 15th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions Naples (ISHPMIE) CY - Naples, Italy DA - 10.06.2024 KW - Multi-Layer Insulation KW - Cryogenic KW - Liquid Hydrogen KW - Heat Transfer KW - Hydrogen Storage PY - 2024 AN - OPUS4-60457 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eberwein, Robert A1 - Hajhariri, Aliasghar A1 - Davide, Camplese A1 - Giordano, Emrys Scarponi A1 - Valerio, Cozzani A1 - Frank, Otremba T1 - Experimental investigation on the behavior of thermal super insulation materials for cryogenic storage tanks in fire incidents N2 - The number of vehicles using or transporting cryogenic fuels such as Liquefied Hydrogen (LH2) or Liquefied Natural Gas (LNG) increases fast in the land transportation sector. Does this also entail new risks? The storage of cryogenic fuels requires tanks with Thermal Super Insulations (TSI) to keep the fluid cold and limit the formation of boil-off gas. TSI has proven itself in some applications since the middle of the 20th century, but in the land transport sector they are still quite new, where accidents involving fires, collisions, and their combination are to be expected. This work focuses on investigating the behavior of different types of TSI while exposed to a heat source representing a fire. To this aim, a High-Temperature Thermal Vacuum Chamber (HTTVC) was applied, which allows the thermal loading of a thermal insulation material in a vacuum and measuring the heat flow transported through the TSI in parallel. In this study, the results of 6 samples are presented regarding 3 types of MLI, rock wool, perlites, and microspheres. The thermal exposure caused different effects on the samples. In practice, this can be connected to the rapid release of flammable gases as well as to a Boiling Liquid Expanding Vapour Explosion (BLEVE). These results are relevant for reducing the risks to people and infrastructures in the progressive establishment of tanks for cryogenic fluids in our industry and society. The data presented in the study can be used to improve the design of tanks and TSIs, the assessment of accident scenarios, and the development of measures for first responders. KW - Liquefied hydrogen KW - Liquefied natural gas KW - Tanks KW - Fire KW - Insulation KW - MLI KW - Perlite KW - Rock wool KW - Microspheres PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599947 DO - https://doi.org/10.1016/j.psep.2024.04.131 SN - 0957-5820 VL - 187 SP - 240 EP - 248 PB - Elsevier AN - OPUS4-59994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberwein, Robert A1 - Hajhariri, Aliasghar A1 - Camplese, D. A1 - Scarponi, G. E. A1 - Cozzani, V. A1 - Otremba, Frank T1 - Insulation Materials Used in Tanks for the Storage of Cryogenic Fluids in Fire Scenarios N2 - The importance of tanks for storing cryogenic fluids in the energy industry is increasing because of ongoing political conflicts and the implementation of more environmentally friendly energy sources. Key representatives for the application of cryogenic tanks are natural gas in the form of Liquefied Natural Gas (LNG) and hydrogen, e. g. in the form of Liquefied Hydrogen (LH2), for which significantly higher transport capacities can be achieved with the same transport volume using cryogenic storages than with storages based solely on overpressure. What applies to all cryogenic transported fluids in common is their condition that must be maintained. Hence heat flows into the preserved fluid must be minimized. Thermal super Insulations (TSI) based on e. g. multilayer insulations (MLI), perlites, and vacuum are utilized for this purpose and have already proven themselves in similar applications. However, for the use of tanks for cryogenic fluids in the transport sector, there is insufficient knowledge regarding the course and consequences of incidents, which is due to the still short period of use and the few documented incidents, hence few investigations carried out in this field. Typical scenarios in the transport sector represent car accidents with collisions, fires, and their combination, which are associated with extraordinary loads on the tank. The focus of this study is to investigate the behavior of TSI as a result of their thermal exposure to a heat source representing a fire. It is worth mentioning that this could lead to an increase of the heat flux into a tank by several orders of magnitude, and to permanent damage of the TSI, ultimately rapid release of flammable gas as well as a Boiling Liquide Expanding Vapour Explosion (BLEVE). For this purpose, a high temperature thermal vacuum chamber (HTTVC) has been developed that allows thermal loading of MLI or perlites in a vacuum and simultaneous measurement of heat flow through this TSI. The HTTVC is designed to represent realistic insulation conditions and to withstand thermal loads from typical design fires. The HTTVC was applied to investigate TSI based on MLI and vacuum. It is shown that the thermal stress caused permanent damage to the TSI, with shrinkage, phase change, pyrolysis, and condensation being significant damage mechanisms. The results are relevant for the evaluation of accident scenarios and can thus contribute to the improvement of TSI and the development of emergency measures for the protection of persons and infrastructures. T2 - ASME 2023 Pressure Vessels & Piping Conference (PVP2023) CY - Atlanta, Georgia, USA DA - 16.07.2023 KW - LH2 KW - LNG KW - Fire KW - MLI KW - Safety PY - 2023 AN - OPUS4-57974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hajhariri, Aliasghar T1 - Behavior of a LH2 storage tank under fire N2 - As the world moves towards green energy production, effective storage and transportation solutions become essential. To support this transition, energy carriers with minimal or zero environmental impact are required. Liquified hydrogen represents a promising candidate due to its emissions-neutral properties. However, its highly flammable nature necessitates adherence to strict safety codes and standards. Storing hydrogen often requires advanced super-insulation materials. To enhance the safety of cryogenic hydrogen storage tanks under extreme conditions, such as those encountered during fire accidents, it is crucial to understand the thermal behaviour of the tank. Predicting pressurization and potential failure in advance demands a robust and comprehensive model. However, still such models suffer lack of detailed heat transfer models which account for various sub-processes during an accident scenario. Hence, this study introduces a comprehensive model for the pressurization of cryogenic tanks equipped with multi-layer insulation (MLI) systemsin the event of fire, which comprises several sub-models. These sub-models account for heat transfer phenomena through the thermal insulation at nominal conditions and its thermal degradation during fire exposure, the fluid, the internal pressurization, and the performance of the pressure relief valve. This study provides valuable insights into the safety and the behaviour of hydrogen storage tanks under thermal loads. T2 - 18th EFCE International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bologna, Italy DA - 08.06.2024 KW - Hydrogenstorage KW - Cryogenic Storage KW - Safety KW - Heat Transfer KW - MLI PY - 2025 AN - OPUS4-63479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. A1 - Hajhariri, Aliasghar A1 - Sklorz, Christian A1 - Kriegsmann, Andreas A1 - Müller, Karsten T1 - A modular concept for protection against debris flight - Design, properties and usage N2 - With advances in technological development, stationary and mobile storage units for compressed hydrogen are becoming larger and larger. Their number is also increasing. At the same time, their design has evolved from steel and aluminium to pressure vessels made of composite materials. For safety reasons the design approval of those composite cylinders requires fire engulfment tests, which are mainly organised as open-air tests always needs dedicated protection measures. Under some conditions those protections measures even reduce the effort for organisational safety measures if e.g. the emission of splinters can get totally prevented. Another aspect is the improved reproducibility of fire tests by reducing the influence of wind. Between 2017 and 2019, BAM developed a stackable protective frame made of steel to safely capture splinters for the safe execution of high-energy impact tests. However, this frame was not flexible enough for the follow-up project, which led to a completely new protection concept for (potentially) destructive tests on gas-filled pressure vessels. This concept is based on very robust building blocks made from welded steel. Despite their considerable weight of around 500 kg p.p., they can be combined and stacked very easily like ‘Lego bricks’. The presentation will show the flexibility of the concept, some results of tests on the robustness against pressure waves and the effectiveness in wind attenuation. Finally, the interaction with a new, also modular burner concept for localised fires and full engulfment fires will be presented. T2 - 11th International conference on hydrogen safety (ICHS 2025) CY - Seoul, Republic of Korea DA - 22.09.2025 KW - Splinter protection KW - Pressure vessel testing KW - Fire engulfment KW - Destructive tests KW - Rupture KW - Gaseous tests KW - Pressure wave KW - Test equipment KW - Precaution measures PY - 2025 SN - 979-1-2243-0274-2 VL - 2025 SP - 1428 EP - 1439 AN - OPUS4-65100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hajhariri, Aliasghar A1 - Eberwein, Robert A1 - Perrone, Luca Pakj A1 - Cozzani, Valerio A1 - Otremba, Frank A1 - Seidlitz, Holger T1 - Study the impact of spacer at thermal degradation process of MLI-based insulation in fire condition N2 - To reduce CO2 emissions, energy carriers such as hydrogen are considered to be a solution. Consumption of hydrogen as a fuel meets several limitations such as its low volumetric energy density in gas phase. To tackle this problem, storage as well as transportation in liquified phase is recommended. To be able to handle this component in liquid phase, an efficient thermal insulation e.g., MLI insulation is required. Different studies have been addressed the vulnerability of such insulation against high thermal loads e.g., in an accident engaging fire. Some of research works have highlighted the importance of considering the MLI thermal degradation focusing on its reflective layer. However, limited number of studies addressed the thermal degradation of spacer material and its effect on the overall heat flux. In this study, through systematic experimental measurements, the effect of thermal loads on glass fleece, glass paper as well as polyester spacers are investigated. The results are reported in various temperature and heat flux profiles. Interpreting the temperature profiles revealed that, as the number of spacers in the medium increases, the peak temperature detectable by the temperature sensor on the measurement plate decreases. Each individual spacer contributes to mitigating the radiative energy received by the measurement plate. Stacks of 20–50 spacers (this is the number of layers in commercial MLI systems applied for liquid hydrogen applications) can potentially reduce the thermal radiation by 1–2 orders of magnitude. An empirical correlation to predict a heat flux attenuation factor is proposed, which is useful for further numerical and analytical studies in the temperature range from ambient to 300 ◦C. KW - Cryogenic KW - Liquid Hydrogen KW - Multi-Layer Insultation KW - Heat Transfer KW - Hydrogen Storage Safety PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614919 DO - https://doi.org/10.1016/j.jlp.2024.105461 SN - 0950-4230 VL - 92 SP - 1 EP - 7 PB - Elsevier Ltd. AN - OPUS4-61491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Camplese, Davide A1 - Scarponi, Giordano Emrys A1 - Eberwein, Robert A1 - Hajhariri, Aliasghar A1 - Otremba, Frank A1 - Cozzani, Valerio T1 - Modelling Fire Response of Cryogenic Liquid Hydrogen Tanks Equipped with Multilayer Insulation (MLI) Systems N2 - In the context of the growing global interest in hydrogen-based green energy, cryogenic tanks equipped with multi-layer insulation (MLI) are emerging as a leading solution for storing hydrogen in vehicles. The integrity of these systems might be threatened during fire exposure. This can trigger the degradation of the MLI materials and induce rapid pressurization of the tank with a high risk of catastrophic failure. In this work, a novel lumped model to simulate the thermal response of MLI-equipped cryogenic liquid hydrogen tanks is presented. The model integrates the accurate database “Coolprop” for hydrogen thermodynamic properties and sub-models for detailed simulation of MLI degradation, providing a realistic simulation of the experimental data obtained under normal operating conditions. The application of the model to several case studies considering different numbers of MLI layers and tank geometries demonstrates that aluminum-based MLI offers scarce protection in case of exposure to a hydrocarbon poolfire. T2 - CISAP 11 CY - Neapel, Italy DA - 15.09.2024 KW - LH2 KW - LNG KW - Cryogenic storage tank KW - Insulation KW - MLI PY - 2024 DO - https://doi.org/10.3303/CET24111076 SN - 2283-9216 VL - 111 SP - 451 EP - 456 PB - AIDIC The Italian Association of Chemical Engineering AN - OPUS4-61384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -