Can a Liquid Hydrogen Storage Tank BLEVE?

A BLEVE (boiling-liquid expanding-vapor explosion) occurs when a tank containing liquefied gas ruptures, resulting in the instantaneous release of the vapor, boiling liquid, missiles (tank fragments), and blast wave¹. The most common type of the BLEVE is caused when the external wall of the tank is exposed to a fire¹. The continuous heat transfer from the fire to the tank wall increases the temperature and pressure inside the tank, until the tank fails. This sudden failure of the tank results in an explosive vaporization of its contents.

In passenger cars the LH₂ is stored as a cryogenic liquid at -240^o C and at moderate pressures (20 to 30 bars)². It is believed that the LH₂ will not BLEVE, since it is stored at such a low temperature³. However, LNG, which is also stored as a cryogenic liquid presents a potential for BLEVE⁴. Consequently, in this study we have theoretically investigated if the LH₂ storage tanks will BLEVE.

A theoretical model considering transient mass and energy transfer is developed and solved numerically⁵. It is assumed that the LH₂ tank is engulfed in a fire and the fire is caused due to spilled gasoline or hydrogen. Different tank materials and insulations are tested. The transient model has a capability to predict the time required for the LH₂ tank to BLEVE. This prediction will be useful for the fire fighters and emergency responders when dealing with LH₂ tank engulfed in a fire. Finally the consequences due to the BLEVE of LH₂ tank are also studied.

References

1. Abbasi, T. and S. A. Abbasi (2007). "The boiling liquid expanding vapour explosion (BLEVE): Mechanism, consequence assessment, management." Journal of Hazardous Materials 141(3): 489-519.
2. Rigas, F. and S. Sklavounos (2005). "Evaluation of hazards associated with hydrogen storage facilities." International Journal of Hydrogen Energy 30(13-14): 1501-1510.
3. C. J. H. van den Bosch, R. A. P. M. W. (2005). Methods for the calculation of physical effects - due to the releases of hazardous materials (liquids and gases) - 'Yellow Book'. The Hague, Committee for the Prevention of Disasters.
4. Pitblado, R. (2007). "Potential for BLEVE associated with marine LNG vessel fires." Journal of Hazardous Materials 140(3): 527-534.
5. Runnels, D. S. R. (2008). AFFTAC: Analysis of Fire Effects on Tank Cars.