TY - JOUR A1 - Mazzola, T. A1 - Hanna, S. A1 - Chang, J. A1 - Bradley, S. A1 - Meris, R. A1 - Simpson, S. A1 - Miner, S. A1 - Gant, S. A1 - Weil, J. A1 - Harper, M. A1 - Nikmo, J. A1 - Kukkonen, J. A1 - Lacome, J.-M. A1 - Nibart, M. A1 - Björnham, O. A1 - Khajehnajafi, S. A1 - Habib, Abdel Karim A1 - Armand, P. A1 - Bauer, T. A1 - Fabbri, L. A1 - Spicer, T. A1 - Ek, N. T1 - Results of comparisons of the predictions of 17 dense gas dispersion models with observations from the Jack Rabbit II chlorine field experiment N2 - The Jack Rabbit II (JR II) chlorine field trials in 2015 and 2016 involved nine 5–20 ton releases of pressurized liquefied chlorine from a tank mounted 1 m above a broad flat desert sand surface. A model comparison study was initiated, where 17 widely-used dense-gas dispersion models were run by scientists in seven countries. Predictions were submitted following specified formats, using specified emissions and meteorology inputs. To compare with the model predictions, sets of observations were defined for the arc-maximum 1–3 s averaged concentrations (arc max C) and for cloud widths and heights (to 20 ppm and 200 ppm contours) at distances from 0.2 to 11.0 km from the release. The initial focus is on the three field trials (1, 6, and 7) that have the highest observed concentrations and that have detailed emissions information. It is found that these models are able to satisfactorily simulate (generally within a factor of two) the observed arc max C's and their variation with downwind distance at this flat desert site. At each downwind distance, the scatter in the arc max C predictions covers about 1 ½ orders of magnitude, but the observed arc max C is within the range of the predictions. The median of the cloud width predictions is about 50% larger than the observed value for the three trials. The median of the cloud height predictions is within about 10% of the observed value. For both cloud width and/or height, there are a few models with large (factor of 3 or higher) overpredictions. Of the 17 models, when compared to observations, there is a core group of 5 or 6 with consistently (across all three trials and all distances) less mean error and scatter in their predictions of arc max C and cloud width and height. However, as a group, the 17 models are performing adequately (using the “factor of two” rule of thumb). An important caveat is that, at the JR II desert site, chlorine deposition is minimal. At a site with vegetation and/or organic-rich soil, the effects of removal of chlorine by deposition are expected to be significant. KW - Jack rabbit II KW - Chlorine KW - Field experiment KW - Dense gas dispersion KW - Model evaluation PY - 2021 DO - https://doi.org/10.1016/j.atmosenv.2020.117887 VL - 244 SP - 1 EP - 14 PB - Elsevier B.V. AN - OPUS4-60740 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 - Kant, Hanjo A1 - Schulze, Marcel A1 - Orchini, Alessandro T1 - Sicherheitstechnische Untersuchungen von Wasserstoff Freistrahlflammen bei Hochdruck im Realmaßstab N2 - Wasserstoff als Energieträger gewinnt zunehmend an Bedeutung. Die Untersuchung von Störfallauswirkungen mit Wasserstoff rückt somit stärker in den Fokus. Da Wasserstoff meist unter Druck gelagert und transportiert wird, ist ein zu betrachtendes Szenario die Freisetzung aus einer Leckage mit anschließender Zündung. Die daraus resultierende Freistrahlflamme (Jet Flame) muss hinsichtlich der in die Umgebung emittierten Wärmestrahlung charakterisiert werden. In der Literatur existieren bereits verschiedene Modelle, welche jedoch vermehrt auf Daten aus Kohlenwasserstoffflammen mit geringem Impuls basieren. Zur Überprüfung dieser Modelle wird im Zuge des BAM internen H2 Jet Flame Projektes die sicherheitstechnische Untersuchung von impulsbehafteten Wasserstoff Freistrahlflammen vorgenommen. Hierfür finden Versuche im Realmaßstab auf dem Testgelände Technische Sicherheit der BAM (BAM-TTS) statt. Gegenstand der Untersuchungen ist die Beurteilung der Auswirkungen von realistischen Freisetzungsszenarien hinsichtlich der Flammengeometrie und der freigesetzten Wärmestrahlung. Dabei werden Parameter wie Freisetzungswinkel, Leckagedurchmesser (z.Zt. 1 mm bis 10 mm), Druck (z.Zt. bis max. 250 bar) und Massenstrom (bis max. 0,5 kg/s) variiert. Zusätzlich können auch Einflüsse wie Art der Zündung, Zündort sowie Zündung mit zeitlichem Verzug untersucht werden. Gewonnene Erkenntnisse werden mit den Ergebnissen bereits vorhandener Modelle verglichen und diese im Bedarfsfall weiterentwickelt. Insbesondere wird der Fokus auf die Modellierung der freigesetzten Wärmestrahlung von Wasserstoffflammen gelegt. Herausforderung dabei stellt die IR-Vermessung und Modellierung von Sichtmodellen der Flammen dar. Die Visualisierung der Flammengeometrie wird mit Hilfe mehrerer Infrarot Kamerasystemen (aus mindestens zwei Blickwinkeln) vorgenommen. Bisherige Messungen, die in der Literatur zu finden sind, basieren meist auf instationären Auströmbedingungen. Der hier verwendete Versuchsaufbau ermöglicht ein stationäres Ausströmen für mehrere Minuten und somit eine direkte Vergleichbarkeit mit den existierenden (stationären) Modellen. Weiterhin ist der Versuchsstand umrüstbar für Vergleichsmessungen mit Kohlenwasserstoffen (Methan etc.) sowie Mischungen aus Wasserstoff und Kohlenwasserstoffen. T2 - Magdeburg-Köthener Brandschutz- und Sicherheitstagung 2024 CY - Magdeburg, Germany DA - 14.03.2024 KW - Wärmestrahlung KW - Wassersoff KW - Freistrahlflamme PY - 2024 SN - 978-3-948749-42-2 SP - 137 EP - 146 CY - Magdeburg AN - OPUS4-59912 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schalau, Bernd A1 - Habib, Abdel Karim T1 - Lachenverdunstung bei höheren Dampfdrücken N2 - Bei vielen Störfallauswirkungsbetrachtungen, insbesondere im Rahmen des Leitfadens KAS-18, ist die Betrachtung einer Lachenverdunstung bzw. –verdampfung erforderlich. Für die Berechnung des Verdunstungsmassenstroms werden üblicherweise empirische Modelle eingesetzt. Ein grundsätzlicher Unterschiedzwischen den Modellen ist die Berücksichtigung des Dampfdrucks der freigesetzten Flüssigkeit. In einigenModellen wird eine lineare, in anderen eine logarithmische Abhängigkeit angenommen. Dies führt bei Stoffen mit einer Siedetemperatur, die nur geringfügig über der Umgebungstemperatur liegt, oder bei der Freisetzung von heißen Flüssigkeiten zu gravierenden Unterschieden in den berechneten Massenströmen. Ein weiteres Problem ergibt sich bei der Betrachtung einer Lachenverdunstung in einem Lager. Da der mit den empirischen Modellen berechnete Verdunstungsmassenstrom proportional zur Strömungsgeschwindigkeit ist, und in einem Lager diese als gering angenommen werden kann, stellt sich die Frage, ob die Modelle für dieses Szenario anwendbar sind. Durch eigene experimentelle Untersuchungen im Freifeld, in einem Lagerraum und in einer Lagerhalle wurde eine Grundlage für die Beantwortung dieser Fragen geschaffen. PY - 2015 SN - 2191-0073 VL - 5 IS - 9 SP - 22 EP - 27 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-34312 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim T1 - Untersuchung der Freistzung von Flüssigwasserstoff auf und unter Wasser N2 - In einer Reihe von Experimenten wurden die möglichen Folgen der Freisetzung von verflüssigtem Wasserstoff (LH2) auf, bzw. unter Wasser untersucht. Die Experimente zielten darauf ab, eine unbeabsichtigte Freisetzung von LH2 (z.B. durch Schlauchabriss) insbesondere bei der Betankung eines Schiffes zu simulieren. Für verflüssigtes Erdgas (LNG) wurden dabei sog. RPT’s (rapid phase transition) nachgewiesen, bei denen die spontane Verdampfung relevante Druckwellen erzeugt. Es kann nicht ausgeschlossen werden, dass RPTs auch im Falle von LH2 möglich sind. Die Versuche wurden auf dem Testareal Wasserstoffsicherheit auf dem Testgelände Technische Sicherheit der Bundesanstalt für Materialforschung und -prüfung (BAM-TTS) in Horstwalde, im Rahmen einer Forschungskooperation zwischen der BAM und Gexcon im Rahmen des SH2IFT-Programms durchgeführt. Die LH2-Freisetzungen erfolgten direkt aus einem LH2-Tanklastwagen über eine lange, flexible, vakuumisolierte Transferleitung. Während die Freisetzung oberhalb und unterhalb der Wasseroberfläche jeweils vertikal orientiert war, wurde bei der Unterwasserfreisetzung zusätzlich eine horizontale Ausströmung, parallel zur Wasseroberfläche realisiert. Zur Bestimmung des Massenstromes, wurde ein Wägesystem unter dem Tankwagen eingesetzt. Spezielle Drucksensoren wurden verwendet, um die durch die Freisetzungsvorgänge erzeugten Stoßwellen sowohl im Wasser als auch in der Luft zu messen. Die Gaskonzentrationen über dem Wasserbecken wurden an verschiedenen Positionen gemessen. Hochgeschwindigkeits-, Infrarot- (IR) und normale Kameras wurden eingesetzt, um die Phänomenologie der Freisetzung aufzuzeichnen und das Verhalten der Gaswolke im Zeitverlauf zu verfolgen. Neben den fest installierten Systemen an Land, kamen auch Unterwasserkameras sowie eine Drohne mit Normal- und IR-Kameras zum Einsatz. Zwei Wetterstationen wurden zur Messung von Windgeschwindigkeit, Windrichtung, Temperatur und Luftfeuchtigkeit während aller durchgeführten Tests eingesetzt. Des Weiteren kamen Bolometer zur Wärmestrahlungsmessung zum Einsatz. Zwar führten die Freisetzung zu einer hochturbulenten LH2/Wasser Mischzone, jedoch zu keinen nennenswerten Überdrücken durch RPT. Im Gegensatz dazu wurde unerwartet, aber reproduzierbar, eine Zündung der Gaswolke in freier Luft in einiger Entfernung von den Instrumenten und dem Ort der Freisetzung beobachtet. Die daraus resultierenden Gaswolkenexplosionen führten zu relevanten Überdrücken und zur Wärmeabstrahlung in die Umgebung. T2 - Magdeburg-Köthener Brandschutz- und Sicherheitstagung 2024 CY - Magdeburg, Germany DA - 14.03.2024 KW - LH2 KW - Flüssigwasserstoff KW - Gaswolkenexplosion KW - Freisetzung KW - RPT PY - 2024 AN - OPUS4-59716 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tamburini, Federica A1 - Kluge, Martin A1 - Habib, Abdel Karim A1 - Ustolin, Federico A1 - Cozzani, Valerio A1 - Paltrinieri, Nicola T1 - Exploring experimental tests concerning liquid hydrogen releases N2 - In recent years, the adoption of liquid hydrogen (LH2) has increased significantly in industrial and transport applications, driven by its low carbon footprint, thereby aiding the fight against global warming. Additionally, its high volumetric energy density, compared to gaseous or compressed hydrogen, enhances hydrogen storage capabilities. However, safety remains a major concern due to its physical-chemical properties and inherent hazardous characteristics, especially in the event of spillage scenarios. Therefore, to better understand the consequences of LH2 releases onto or into water, large-scale experimental tests were conducted by Bundesanstalt für Materialforschung und -prüfung (BAM) within the Safe Hydrogen Fuel Handling and Use for Efficient Implementation (SH2IFT) project at the Test Site Technical Safety of BAM, comprising 75 single spill events at varied release rates and orientations. While the rapid phase transition (RPT) phenomenon was not observed, selfignition of the hydrogen-air cloud occurred, accompanied by blast wave overpressure and heat radiation, without a discernible ignition source. These findings emphasize the need for further investigation into LH2 safety. Leveraging experimental data for real-world applications provides insights into safe LH2 infrastructure implementation, laying foundational knowledge for addressing safety challenges and advancing LH2 technology. KW - Liquid Hydrogen KW - Rapid phase transition KW - Ignition KW - Safety PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618644 DO - https://doi.org/10.1016/j.psep.2024.11.014 SN - 0957-5820 VL - 192 SP - 1330 EP - 1343 PB - Elsevier CY - Amsterdam AN - OPUS4-61864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mazzola, T. A1 - Hanna, S. A1 - Chang, J. A1 - Bradley, S. A1 - Meris, R. A1 - Simpson, S. A1 - Miner, S. A1 - Gant, S. A1 - Weil, J. A1 - Harper, M. A1 - Nikmo, J. A1 - Kukkonen, J. A1 - Lacome, J.-M. A1 - Nibart, M. A1 - Björnham, O. A1 - Khajehnajafi, S. A1 - Habib, Abdel Karim A1 - Armand, P. A1 - Bauer, T. A1 - Fabbri, L. A1 - Spicer, T. A1 - Ek, N. T1 - Results of comparisons of the predictions of 17 dense gas dispersion models with observations from the Jack Rabbit II chlorine field experiment N2 - The Jack Rabbit II (JR II) chlorine field trials in 2015 and 2016 involved nine 5–20 ton releases of pressurized liquefied chlorine from a tank mounted 1 m above a broad flat desert sand surface. A model comparison study was initiated, where 17 widely-used dense-gas dispersion models were run by scientists in seven countries. Predictions were submitted following specified formats, using specified emissions and meteorology inputs. To compare with the model predictions, sets of observations were defined for the arc-maximum 1–3 s averaged concentrations (arc max C) and for cloud widths and heights (to 20 ppm and 200 ppm contours) at distances from 0.2 to 11.0 km from the release. The initial focus is on the three field trials (1, 6, and 7) that have the highest observed concentrations and that have detailed emissions information. It is found that these models are able to satisfactorily simulate (generally within a factor of two) the observed arc max C’s and their variation with downwind distance at this flat desert site. At each downwind distance, the scatter in the arc max C predictions covers about 1 ½ orders of magnitude, but the observed arc max C is within the range of the predictions. The median of the cloud width predictions is about 50% larger than the observed value for the three trials. The median of the cloud height predictions is within about 10% of the observed value. For both cloud width and/or height, there are a few models with large (factor of 3 or higher) overpredictions. Of the 17 models, when compared to observations, there is a core group of 5 or 6 with consistently (across all three trials and all distances) less mean error and scatter in their predictions of arc max C and cloud width and height. However, as a group, the 17 models are performing adequately (using the “factor of two” rule of thumb). An important caveat is that, at the JR II desert site, chlorine deposition is minimal. At a site with vegetation and/or organic-rich soil, the effects of removal of chlorine by deposition are expected to be significant. KW - Jack rabbit II chlorine field experiment KW - Dense gas dispersion KW - Model evaluation PY - 2021 DO - https://doi.org/10.1016/j.atmosenv.2020.117887 VL - 244 SP - 117887 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-51845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Habib, Abdel Karim T1 - Consequences of exposing cryogenic storage vessels containing liquid hydrogen to a fire load N2 - Within a research cooperation between BAM and Gexcon as part of the SH2IFT program, large scale experiments have been performed at the Test Site Technical Safety of the Bundesanstalt für Materialforschung und –prüfung (BAM) to determine the hazards emerging from a vacuum insulated cryogenic storage vessel containing liquified hydrogen (LH2) is caught in a fire engulfing it. T2 - ELVHYS, 2nd Safety Workshop CY - Online meeting DA - 29.11.2023 KW - BLEVE KW - Cryoegenic storage vessel KW - Liquified hydrogen PY - 2023 AN - OPUS4-59021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - van Wingerden, Kees ED - Beyer, Michael ED - Lucassen, Arnas T1 - Experimental investigation into the consequences of release of liquified hydrogen onto and under water N2 - Large-scale experiments have been performed to investigate the possible consequences of realistic amounts of liquified hydrogen (LH2) encountering water. The experiments aimed at simulating an accidental release of LH2 during especially the fuelling of a ship. For liquified natural gas (LNG) it has been demonstrated that when spilled onto water the evaporation rate can be that high that physical explosions occur which are referred as rapid phase transitions (RPTs). It cannot be excluded that RPTs are also possible in the case of LH2. The tests were performed in a 10 m x 10 m x 1.5 m basin filled with water, at the Test Site Technical Safety of the Bundesanstalt für Materialforschung und –prüfung (BAM) in Horstwalde, Germany within a research cooperation between BAM and Gexcon as part of the SH2IFT program. LH2 releases were established releasing directly from a trailer carrying LH2 through a long flexible double vacuum insulated transfer line. The releases occurred from a height of 50 cm above and 30 cm under the water surface both pointing downwards and 30 cm under the water surface pointing along the water surface too. The release rate was determined based on the weight loss rate of the road tanker which was placed onto load cells. Special blast pressure sensors were used to measure the shock waves generated by the release processes both in the water and in the air. At several locations the gas concentration was measured. Heat radiation was measured at 3 distances from the point of release. High speed, Infrared (IR) and normal cameras were used to record events and to follow the gas cloud behaviour in time. This includes cameras mounted on a UAV and underwater cameras. Two weather stations were used to measure wind speed, wind direction, temperature and humidity during all tests performed. All investigated release configurations resulted in a very chaotic LH2-water mixing zone, causing considerable evaporation but only minor over pressures. The main phenomenon observed was an ignition of the released gas cloud, resulting in significant blast wave overpressures and heat radiation to the surroundings. The location of the ignition occurred in free air at some distance from the instrumentation and release location. T2 - 14th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions (ISHPMIE 2022) CY - Braunschweig, Germany DA - 11.07.2022 KW - LH2 KW - RPT KW - Release KW - Gas cloud explosion KW - Heat radiation PY - 2022 SP - 182 EP - 196 AN - OPUS4-59441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schalau, Bernd A1 - Bernardy, Christopher A1 - Habib, Abdel Karim T1 - Modellierung von Wasserstoff - Freistrahlflammen N2 - Bei der Freisetzung von Wasserstoff aus Ausbläsern kann nicht ausgeschlossen werden, dass es zu einer Selbstentzündung und der Bildung einer Freistrahlflamme kommt. Als Auswirkungen für die Umgebung sind der Explosionsüberdruck bei der Zündung und die Wärmestrahlung im Rahmen einer Gefährdungsbeurteilung zu betrachten. In der Literatur sind verschiedene Ansätze für die Modellierung einer Wasserstoff-Freistrahlflamme zu finden, wobei viele sich mit der Berechnung der Flammenlänge befassen. Experimentelle Freifeld-Untersuchungen unter Windeinfluss und entsprechende Modellierungen der Wärmestrahlung in der Umgebung einer Wasserstoff-Freistrahlflamme liegen nur wenig vor. In der Bundesanstalt für Materialforschung und -prüfung BAM sind solche Experimente durchgeführt worden und die daraus abgeleitete Modellierung wird im Folgenden vorgestellt. KW - Freistrahlflamme KW - Auswirkungsbetrachtung PY - 2025 SN - 2191-007 VL - 15 IS - 05-06 SP - 16 EP - 24 CY - Düsseldorf AN - OPUS4-63709 LA - deu 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 - Habib, Abdel Karim T1 - Heat radiation emanating from hydrogen and methane jet fires N2 - Modelling the heat radiation emanating from jet flames for hazard assessment purposes, is generally done using simple, steady-state approaches that give a quick result and estimation of the consequences to account for. Although nowadays computational fluid dynamics 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 the simpler approaches as for example the Model of Chamberlain or Johnson (mainly developed for hydrocarbon flames) 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 jet flame models were mainly developed based on data from hydrocarbon jet flame experiments, it is to be verified, that 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. Parameters such as leakage diameter (ranging from 1 mm to 10 mm), pressure (up to max. 250 bar), release orientation (vertical or horizontal) and mass flow (up to max. 0.5 kg/s) are varied. In particular, the focus is laid on the measurement and modelling of the thermal radiation. 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. The experimental setup used here allows for the generation of a steady-state outflow for several minutes 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 not only accounting for their accuracy in predicting the heat radiation but also with regard to possible needs of further development of the models. 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 AN - OPUS4-63696 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 - Gant, Simon A1 - Chang, Joseph A1 - Hetherington, Rory A1 - Hanna, Steven A1 - Tickle, Gemma A1 - Spicer, Tom A1 - McMasters, Sun A1 - Fox, Shannon A1 - Meris, Ron A1 - Bradley, Scott A1 - Miner, Sean A1 - King, Matthew A1 - Simpson, Steven A1 - Mazzola, Thomas A1 - McGillivray, Alison A1 - Tucker, Harvey A1 - Björnham, Oscar A1 - Carissimo, Bertrand A1 - Fabbri, Luciano A1 - Wood, Maureen A1 - Habib, Abdel Karim A1 - Harper, Mike A1 - Hart, Frank A1 - Vik, Thomas A1 - Helgeland, Anders A1 - Howard, Joel A1 - Mauri, Lorenzo A1 - Mackie, Shona A1 - Mack, Andreas A1 - Lacome, Jean-Marc A1 - Puttick, Stephen A1 - Ibrahim, Adeel A1 - Miller, Derek A1 - Dharmavaram, Seshu A1 - Shen, Amy A1 - Cunningham, Alyssa A1 - Beverly, Desiree A1 - O’Neal, Daniel M. A1 - Verdier, Laurent A1 - Burkhart, Stéphane A1 - Dixon, Chris A1 - Nilsen, Sandra A1 - Bradley, Robert A1 - Skarsvåg, Hans L. A1 - Fyhn, Eirik H. A1 - Aasen, Ailo T1 - Pressure-Liquefied Ammonia Jet Dispersion: Multi-Model Intercomparison Using Desert Tortoise and FLADIS Field Data N2 - This paper presents the findings of an international model inter-comparison exercise that was undertaken in the period 2021-2024 to assess the performance of atmospheric dispersion models for simulating releases of pressure-liquefied ammonia. The exercise used data from ammonia field trials dating from the 1980s and 1990s: the Desert Tortoise and the FLADIS trials. Concentration data from two arcs of sensors in the Desert Tortoise trials and three arcs of sensors in the FLADIS trials were used. Twenty-one independent modelling teams from North America and Europe participated in the exercise and provided in total twenty-seven sets of results from a range of different models, including empirically-based nomograms, integral, Gaussian puff, Lagrangian particle, and Computational Fluid Dynamics (CFD) models. The work is novel in presenting the results from such a large cohort of models, examining specifically the dispersion behaviour of ammonia. This is particularly relevant at the current time, given the growing international interest in using ammonia as a clean energy vector and shipping fuel. The study found that the agreement between model predictions and measurements (as determined by performance measures such as geometric mean bias and geometric variance) varied between different models. At any downwind distance, the range in predicted plume arc-max concentrations spanned a range of up to one or two orders of magnitude about the measurements. Several modelling teams used the same models and, in most cases, their predictions differed. Given appropriate inputs, most models generally predicted concentrations that agreed with the data within commonly-used model acceptance criteria. There was no single class of model that provided superior predictions to others; predictions from several empirically-based nomograms, integral, Gaussian puff, Lagrangian particle, and CFD models were all in close agreement with the data (as defined by the model acceptance criteria). The findings of the exercise are being used to help plan a programme of future ammonia experiments in the USA, called the Jack Rabbit III trials. The results are also useful for assessing the performance of models that may be applied to assess risks at ammonia facilities, and for emergency planning and response. KW - Ammonia KW - Atmospheric dispersion KW - Validation KW - Jack rabbit PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646069 DO - https://doi.org/10.1016/j.aeaoa.2025.100389 SN - 2590-1621 VL - 28 SP - 1 EP - 76 PB - Elsevier Ltd. AN - OPUS4-64606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -