A computational fluid dynamics evaluation of unconfined hydrogen explosions in high pressure applications

The results conclude that high-pressure hydrogen has the potential to build up a large vapor cloud and may explode even without confinement when the leak source is close to the ground. The highest overpressure produced in the simulation was 0.71 barg, which resulted from igniting a hydrogen gas cloud from a 207 bar hydrogen source leaking at 1 m height. The high overpressure suggests that hazard studies for hydrogen leaks near the ground should not assume a free flow jet release. This study also gives a recommended distance from a high-pressure hydrogen processing unit to nearby occupied buildings to use in conjunction with industrial spacing tables for fire hazards.