Cryogenic storage system behaviour under fire : A study of the insulation impact
- The transition from fossil fuels to low-emission alternatives is essential to mitigate carbon emissions in energy-intensive sectors. Liquid hydrogen (LH2) is a promising energy carrier due to its high gravimetric energy density, but its storage requires advanced insulation to minimize heat ingress and prevent excessive boil-off losses. Multilayer insulation (MLI), perlite, and microspheres are commonly used under vacuum conditions, yet their performance under fire exposure remains a critical concern. This study investigates the thermal degradation of insulation materials and its impact on heat transfer in an event with extreme thermal load conditions using the Cryogenic High-Temperature Thermal Vacuum Chamber (CHTTVC). The heat flow dynamics are analyzed, and an equivalent heat transfer coefficient is proposed to quantify the impact of insulation deterioration as the outer wall temperature increases. Additionally, a novel liquid-vapor interface monitoring method is introduced toThe transition from fossil fuels to low-emission alternatives is essential to mitigate carbon emissions in energy-intensive sectors. Liquid hydrogen (LH2) is a promising energy carrier due to its high gravimetric energy density, but its storage requires advanced insulation to minimize heat ingress and prevent excessive boil-off losses. Multilayer insulation (MLI), perlite, and microspheres are commonly used under vacuum conditions, yet their performance under fire exposure remains a critical concern. This study investigates the thermal degradation of insulation materials and its impact on heat transfer in an event with extreme thermal load conditions using the Cryogenic High-Temperature Thermal Vacuum Chamber (CHTTVC). The heat flow dynamics are analyzed, and an equivalent heat transfer coefficient is proposed to quantify the impact of insulation deterioration as the outer wall temperature increases. Additionally, a novel liquid-vapor interface monitoring method is introduced to improve real-time detection of phase changes within the tank. The results highlight that insulation failure substantially increases the heat flow, which, if not mitigated, can lead to boiling liquid expanding vapor explosions (BLEVE), jet fires, or catastrophic tank failure. The findings provide valuable insights into optimizing LH2 storage safety and improving emergency response strategies for cryogenic tanks exposed to extreme thermal conditions.…

