In recent years, the adoption of liquid hydrogen (LH2) in industrial and transport applications is becoming increasingly widespread. The high volumetric energy density of LH2 compared to gaseous or compressed hydrogen allows for efficient storage of the fuel. In particular, LH2 is gaining success in the maritime sector because it allows to reduce carbon emissions with respect to fossil fuels and increase the quantity of hydrogen stocked on board. However, the implementation of such emerging technology is still an open issue in terms of safety. Actually, LH2 shares many of the characteristics of liquified natural gas (LNG), both with respect to chemical and physical properties, and to loss of containment scenarios. Therefore, as there is historical evidence of localized explosions (e.g., rapid phase transition (RPT)) in the case of LNG spills on water, the occurrence of severe consequences when LH2 is released onto water must be investigated. In this respect, several large-scale experiments have been performed to analyse the potential consequences of accidental releases of LH2 in or over water. Specifically, more than 80 single spill events have been carried out at release rates of approximately 0.25 kg/s, 0.50 kg/s, and 0.80 kg/s either above or below the water surface with different orientations. The results showed that the RPT phenomenon was not observed. However, the ignition of the released gas cloud with a blast wave overpressure and heat radiation to the surrounding environment was detected. The unexpected ignition of the flammable cloud is not a well-understood event. Few theories have been proposed to explain the reason behind this phenomenon, but, to date, uncertainty is still present. Based on these considerations, in the present paper, the data collected from the experimental campaign have been considered to investigate the relevance of the outcomes in view of their possible use in real applications. A comparison between the experimental set-up and operating conditions with specific industrial applications has been carried out in order to identify potential lessons learned. Overall, the present study will help laying the foundations for a safe implementation of LH2 infrastructure in the foreseeable future.
Tamburini, F., Ustolin, F., Salzano, E., Cozzani, V., Paltrinieri, N. (2023). Lessons Learned from Experimental Tests concerning Liquid Hydrogen Releases.
Lessons Learned from Experimental Tests concerning Liquid Hydrogen Releases
Tamburini F.
;Salzano E.;Cozzani V.;
2023
Abstract
In recent years, the adoption of liquid hydrogen (LH2) in industrial and transport applications is becoming increasingly widespread. The high volumetric energy density of LH2 compared to gaseous or compressed hydrogen allows for efficient storage of the fuel. In particular, LH2 is gaining success in the maritime sector because it allows to reduce carbon emissions with respect to fossil fuels and increase the quantity of hydrogen stocked on board. However, the implementation of such emerging technology is still an open issue in terms of safety. Actually, LH2 shares many of the characteristics of liquified natural gas (LNG), both with respect to chemical and physical properties, and to loss of containment scenarios. Therefore, as there is historical evidence of localized explosions (e.g., rapid phase transition (RPT)) in the case of LNG spills on water, the occurrence of severe consequences when LH2 is released onto water must be investigated. In this respect, several large-scale experiments have been performed to analyse the potential consequences of accidental releases of LH2 in or over water. Specifically, more than 80 single spill events have been carried out at release rates of approximately 0.25 kg/s, 0.50 kg/s, and 0.80 kg/s either above or below the water surface with different orientations. The results showed that the RPT phenomenon was not observed. However, the ignition of the released gas cloud with a blast wave overpressure and heat radiation to the surrounding environment was detected. The unexpected ignition of the flammable cloud is not a well-understood event. Few theories have been proposed to explain the reason behind this phenomenon, but, to date, uncertainty is still present. Based on these considerations, in the present paper, the data collected from the experimental campaign have been considered to investigate the relevance of the outcomes in view of their possible use in real applications. A comparison between the experimental set-up and operating conditions with specific industrial applications has been carried out in order to identify potential lessons learned. Overall, the present study will help laying the foundations for a safe implementation of LH2 infrastructure in the foreseeable future.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
