Numerical investigation on the effects of dike around liquid hydrogen source on vapor cloud dispersion

Safety is one of the most important concerns in handling liquid hydrogen. Mixture model and Realizable k-epsilon model are adopted to simulate the spills of liquid hydrogen in the present work. Effects of a dike around the liquid hydrogen source on vapor cloud dispersion are numerically investigated. The dike increases the hydrogen concentration near the source, and promotes the upward movement of flammable cloud thanks to the enhanced mixing with air, reducing the cloud detachment distance. The time needed for the hydrogen vapor cloud to be diluted out of hazards is largely influenced by dike size, and introducing the dike does not necessarily increase the overall hazard duration. Increasing the height to length ratio of the dike makes the near-source region exposed to high hydrogen concentration for longer hazard duration, while detachment distance reduces with the increment in dike height. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.