TY - JOUR A1 - Schiaroli, Alice A1 - Mata, Christian A1 - Scarponi, Giordano Emrys A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Ustolin, Federico A1 - Cozzani, Valerio T1 - Digital image processing for the advanced characterization and simulation of experimental fire tests N2 - The fire engulfment of storage tanks of hazardous materials is among the most critical scenarios in hazard assessment of industrial value chains. Laboratory and full-scale experimental trials are used to test the tank performance and integrity in such scenarios. However, strong uncertainties usually affect the actual fire load experienced by the tank, in particular when large-scale experiments are carried out in open test fields. Such uncertainties arise from several factors difficult to control during experimental tests, such as the atmospheric conditions as there is the influence of wind drifts influencing the actual fire engulfment, the flame temperature and the flame dynamic distribution around the target. Consequently, verifying the concordance of an experimental test with standard test criteria and defining accurate boundary conditions in correlated model simulations is challenging. In this study, the development of a novel method for the analysis of fire conditions based on image processing is presented. The approach allows identifying the flame coverage on the target surface during the test and provides an accurate map of the flame distribution on the equipment over time. The approach is tested using experimental data from a full-scale fire test campaign carried out on liquid hydrogen cryogenic tanks. The results prove to be accurate in replicating the experimental temperatures measured on the outer tank shell during the test. The proposed methodology can be used to better understand the results of experimental fire tests and to characterize realistic fire scenarios, also supporting the definition of fire test requirements. Moreover, the approach produces results that can be implemented as advanced space-time-varying boundary conditions in simulation models, improving their accuracy in reproducing real cases. KW - Fire test KW - Digital image processing KW - Flame coverage KW - Storage tank KW - Boundary conditions KW - Fire engulfment PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636956 DO - https://doi.org/10.1016/j.psep.2025.107571 SN - 0957-5820 VL - 201 IS - B SP - 1 EP - 15 PB - Elsevier Ltd. AN - OPUS4-63695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Schalau, Bernd A1 - Kant, Hanjo A1 - Schulze, Marcel A1 - Orchini, Alessandro T1 - Large-scale investigations of the thermal radiation of hydrogen jet flames N2 - For industrial applications dealing with hydrogen, the definition of safety distances and the assessment of possible hazards emanating from releases is mandatory. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the momentum driven release of hydrogen from a leakage with subsequent ignition. In this scenario, the emitted heat radiation from the resulting jet flame to the surroundings has to be determined to define adequate safety distances. For hydrocarbon flames, different jet flame models are available to assess the hazards resulting from an ignited jet release. Since hydrogen flames differ from hydrocarbon flames in their combustion behavior, it has to be checked if these models are also applicable for hydrogen. To evaluate the accuracy of these models for hydrogen jet flames, tests with a horizontal outlet at large-scale are carried out at the BAM Test Site for Technical Safety (BAM-TTS). Herein, the flame geometry and the heat radiation at defined locations in the surroundings are recorded for varying release parameters such as release pressure (currently up to max. 250 bar), mass flow (up to max. 0.175 kg/s) at an outlet diameter of 30 mm (with an upstream nozzle of 7.7 mm). The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. For a better comparability with the steady state jet flame models, the experiments presented here are focused on ensuring a constant mass flow over the release duration (currently 120 s) to obtain a stationary jet flame. In addition, stationary outflow tests with hydrocarbons (methane) were also carried out, which are intended to serve as reference tests for checking flame models based on hydrocarbon data. The comparison of the flame geometry shows that hydrogen jet flames with the same outlet mass flow have a greater flame length (average deviation of 15 %) but a smaller flame diameter than methane jet flames (average deviation of 17 %). Conclusions regarding thermal radiation show that the proportion of total combustion energy emitted as thermal radiation is lower for hydrogen (x_rad= 0.04–0.09) than for methane (x_rad = 0.06–0.1). A comparison of the surface emissive power (SEP) of the jet flame shows a SEP range of 7 kW/m2-15 kW/m2 for hydrogen and 3 kW/m2 - 9,5 kW/m2 for methane. KW - Hydrogen KW - Release KW - Thermal radiation KW - Jet flame KW - Radiant heat fraction PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-622891 DO - https://doi.org/10.1016/j.jlp.2024.105491 SN - 1873-3352 VL - 94 SP - 1 EP - 6 PB - Elsevier B.V. AN - OPUS4-62289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Orchini, A. ED - Fabiano, Bruno ED - Cozzani, Valerio T1 - Heat Radiation Emanating from Hydrogen and Methane Jet Fires N2 - Modelling the heat radiation emanating from jet flames for initial hazard assessment purposes is generally done using simple, steady-state, approaches that give a quick estimation useful for impact analysis. Although nowadays CFD can be used to simulate this phenomenon in detail, it is still very demanding in computational power and time, and generally not all required boundary conditions to achieve a reliable result are known. Therefore, even today simpler empirical approaches are still widely used for consequence analysis. Hydrogen is becoming increasingly important as renewable energy carrier resulting in an increasing demand of “hydrogen-approved” models. Since the aforenamed models were mainly developed based on data from hydrocarbon jet flame experiments, it has to be verified if they also apply to hydrogen jet flames. To this purpose, real-scale tests are carried out at the BAM Test Site Technical Safety (BAM-TTS) with the aim to assess the flame geometry and the emitted thermal radiation of hydrogen and methane jet flames. In particular, the focus is laid on the measurement and modelling of the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. The experimental setup used here allows for the generation of a steady-state outflow and thus a direct comparability with existing (steady-state) models. From these data, an assessment of the applicability of jet flame models to hydrogen jet flames is carried out accounting for their accuracy in predicting heat radiation and possible needs of further development. T2 - 18th EFCE International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bologna, Italy DA - 08.06.2025 KW - Jet Fire KW - Hydrogen KW - Methane KW - Heat radiation PY - 2025 DO - https://doi.org/10.3303/CET25116065 SN - 2283-9216 VL - 116 SP - 385 EP - 390 PB - AIDIC Servizi S.r.l. CY - Italy AN - OPUS4-63698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kluge, Martin A1 - Habib, Abdel Karim ED - Fabiano, Bruno ED - Cozzani, Valerio T1 - Cryogenic LH2 Storage Vessels in a Fire N2 - To investigate the hazards emanating from cryogenic LH2 storage Vessels in a fire, experiments have been performed at the Test Site Technical Safety of the Bundesanstalt für Materialforschung und –prüfung (BAM), Germany. Three double-walled vacuum insulated vessels of 1 m3 volume, filled to approximately 35-40 Vol.% with LH2 were put in a fire. The cylindrical Vessels differed in orientation (horizontal or vertical) and the insulationmaterial used (perlite or multi-layer insulation (MLI)). The fire load was provided by a propane fed burner-system positioned under the storage vessel and designed to give a homogeneous fire load. During the tests the conditions in the vessel (temperatures and pressure) as well as external effects (heat radiation, blast waves, flame ball development and fragmentation) were measured. Two of these vessels, a horizontal and a vertical vessel both insulated with perlite withstood the fire loading for 1 hour 20 minutes and 4 hours respectively without catastrophic failure, but partly showing leakages. The horizontal vessel insulated with MLI failed by bursting after 1 hour and 6 minutes resulting in a fireball, fragments, and blast wave. The test results as well as the detailed examination of the non-destroyed vessels rose some interesting questions which type of insulation might be better to protect a vessel not only during its normal operation but also under fire loading against a heat flux from the surroundings, as well as to the suitability of cryogenic (safety) equipment under fire loading. T2 - 18th EFCE International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bologna, Italy DA - 08.06.2025 KW - LH2 KW - Cryogenic tank KW - Fire engulfment KW - BLEVE PY - 2025 DO - https://doi.org/10.3303/CET25116130 SN - 2283-9216 VL - 116 SP - 775 EP - 780 PB - AIDIC Servizi S.r.l. CY - Italy AN - OPUS4-63697 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin T1 - Cryogenic LH2 storage vessels in a fire N2 - To investigate the hazards emanating from cryogenic LH2 storage Vessels in a fire, experiments have been performed at the Test Site Technical Safety of the Bundesanstalt für Materialforschung und –prüfung (BAM) in Horstwalde, Germany. Three double-walled vacuum insulated vessels of 1 m3 volume, filled to approximately 35-40 Vol.% with LH2 were put in a fire. The cylindrical Vessels differed in orientation (horizontal or vertical) and the insulation material used (perlite or multi-layer insulation (MLI)). The fire load was provided by a propane fed burner-system positioned under the storage vessel and designed to give a homogeneous fire load. During the tests the conditions in the vessel (temperatures and pressure) as well as external effects (heat radiation, blast waves, flame ball development and fragmentation) were measured. The tests showed that the k-type thermocouples used are not suitable for measuring very low temperatures as for example the temperature of the hydrogen liquid phase when using the standard tabled values and conversion functions. An assessment of the measured temperatures could only be done by an own “recalibration” of the thermocouples for the very low temperature range. Bolometers were used to measure the heat radiation generated by a possible fireball/BLEVE. To measure blast generated by the vessel burst/BLEVEs blast pencils were positioned at up to three locations. Further several cameras were used to monitor the events: normal cameras, infrared (IR)-cameras, high-speed cameras also on board of a drone. Two of these vessels, a horizontal and a vertical vessel both insulated with perlite withstood the fire loading for 1 hour 20 minutes and 4 hours respectively without catastrophic failure, but partly showing leakages. The horizontal vessel insulated with MLI failed by bursting after 1 hour and 6 minutes resulting in a fireball, fragments, and blast wave. The test results as well as the detailed examination of the non destroyed vessels rose some interesting questions which type of insulation is better to protect a vessel not only during its normal operation but also under fire loading against a heat flux from the surroundings, as well as to the suitability of cryogenic (safety) equipment under fire loading. T2 - 18th EFCE International Symposium on Loss Prevention and Safety Promotion in the Process Industries CY - Bologna, Italy DA - 08.06.2025 KW - BLEVE KW - LH2 KW - Consequences KW - Cryogenic storage KW - Fire engulfment PY - 2025 AN - OPUS4-63700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bradley, Ian A1 - Kluge, Martin A1 - Habib, Abdel Karim A1 - Scarponi, Giordano Emerys T1 - Experimental Study on Thermal Exposure of Pipes to Steady Hydrogen Jet Fire Impingement N2 - Jet fires resulting from the accidental release of pressurized hydrogen represent a critical issue, especially due to their potential to trigger a domino effect. The lack of studies on the characterisation of the conditions experienced by, and response of, structures and process equipment directly engulfed in a hydrogen jet fire is of concern to industry. This work presents a characterisation study of a hydrogen jet fire with respect to the conditions experienced by an engulfed object. The total heat flux, along with its radiative component, was measured for hydrogen mass flow rates ranging from 0.05 to 0.2 kg/s. Heat fluxes exceeding 700 kW/m2 were measured at a location that coincided with the point of jet impact. The maximum radiative fraction measured was 20 % at the back of the tube where the specimen could receive radiation from the majority of the flame plume. It is concluded that conditions within hydrogen jet fires are notably more severe than those in hydrocarbon jet fires (for which a heat flux of 350 kW/m2 is considered high). This suggests that PFP systems should not be automatically assumed to provide protection against hydrogen jet fires without further research or actual test evidence of performance. KW - Hydrogen KW - Jet Fire KW - Fire Protection KW - Pfp PY - 2025 DO - https://doi.org/10.1016/j.psep.2025.108017 SN - 0957-5820 VL - 204 SP - 1 EP - 15 PB - Elsevier Ltd. AN - OPUS4-64479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Schalau, Bernd A1 - Kant, Hanjo A1 - Schulze, Marcel A1 - Orchini, Alessandro T1 - Experimental Investigation of Large-Scale Hydrogen Diffusion Jet Flames N2 - Hydrogen is a promising alternative to natural gas in industrial energy applications to limit global warming. However, wide application of hydrogen requires specific safety considerations taking into account that hydrogen is stored and transported under much higher pressure than natural gas. Thus, one scenario to be considered for hazard assessment is a sudden release of hydrogen from a leakage or safety valve and its subsequent ignition. For hydrocarbon flames, various jet flame models are available. However, hydrogen flames significantly differ from hydrocarbon flames in their combustion behavior, so that the applicability of these models to hydrogen has to be investigated. For that purpose, reals scale tests were carried out at the BAM Test Site Technical Safety. In these tests, the flame geometry and the thermal heat radiation were investigated for a release angle of 90°, for different release pressures (up to 220 bar) and mass flows (up to 0.175 kg/s). Most existing data on thermal radiation are based on unsteady flow conditions and/or still air, whereas the experiments carried out here ensure a constant mass flow under realistic free-field conditions (with wind influence). This allows a better comparability with the stationary jet flame models and assessment of wind influence on model predictions. A number of parameters such as the surface emissive power and the radiant heat fraction were determined. A detailed comparison of the obtained experimental results with literature radiation models was performed. Based on the investigations, empirical equations for modelling jet flames could be derived. T2 - Proceedings of ASME Turbo Expo 2025 Turbomachinery Technical Conference and Exposition CY - Memphis, Tennessee, USA DA - 16.06.2025 KW - Hydrogen release KW - Radiant heat fraction KW - Thermal radiation KW - Jet flame PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643401 DO - https://doi.org/10.1115/1.4070012 SN - 0742-4795 VL - 148 IS - 5 SP - 51008-1 EP - 51008-8 PB - ASME International AN - OPUS4-64340 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Schalau, Bernd A1 - Schulze, Marcel A1 - Kant, Hanjo A1 - Orchini, Alessandro ED - Ruggiero, Eric J. T1 - Experimental investigation of large-scale hydrogen diffusion jet flames N2 - Hydrogen is a promising alternative to natural gas in industrial energy applications which would serve the goal of limiting global warming. However, wide application of hydrogen requires specific safety considerations taking into account that hydrogen is stored and transported under much higher pressure than natural gas. Thus, one scenario to be considered for hazard assessment is a sudden release of hydrogen from a leakage or safety valve and its subsequent ignition. For hydrocarbon flames, various jet flame models are available. However, hydrogen flames significantly differ from hydrocarbon flames in their combustion behavior, so that the applicability of these models to hydrogen has to be investigated. For that purpose, reals scale tests were carried out at the BAM Test Site Technical Safety. In addition, hydrocarbon jet flames (methane) were investigated. In these tests, the flame geometry and the thermal heat radiation were investigated for a release angle of 90°, for different release pressures (up to 220 bar) and mass flows (up to 0.175 kg/s). While existing heat radiation data from the literature are mostly based on unsteady outflow conditions and/or releases in still air, the experiments presented here are focused on ensuring a constant mass flow over the release duration under realistic free field conditions (with wind influence). This allows a better comparability with the stationary jet flame models and assessment of wind influence on model predictions. A number of parameters such as the surface emissive power of the jet flame and the radiant heat fraction were determined. A detailed comparison of the obtained experimental results with literature radiation models was performed. Good agreement between experimental and literature data was found for hydrogen whereas significant differences were identified for methane. Based on the investigations, empirical equations for modelling jet flames could be derived. T2 - American Society of Mechanical Engineers - Turbomachinery Technical Conference & Exposition GT2025 CY - Memphis, TN, USA DA - 16.06.2025 KW - Hydrogen release KW - Jet flame KW - Radiant heat fraction KW - Thermal radiation PY - 2025 SN - 978-0-7918-8877-3 DO - https://doi.org/10.1115/GT2025-FM2 SP - 1 EP - 11 PB - The American Society of Mechanical Engineers CY - Livingston AN - OPUS4-64098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -