Hazards Associated with the Delayed Ignition of Hydrogen Releases

Whenever hydrogen is present within a system, there is a potential for a hydrogen release. If a release occurs without immediate ignition, a flammable cloud will often develop. These releases present a major safety hazard, as the delayed ignition of a premixed hydrogen-air cloud has the potential to generate significant overpressures. These events are challenging to mitigate, as there are different types of delayed ignition hazards, depending on the nature of the release and its surroundings, each of which can require different mitigation strategies. This presentation outlines the types of delayed ignition hazards a hydrogen release presents, the key parameters that affect their severity, and the most effective strategies to mitigate these events. In addition, current known limitations and gaps in existing codes and standards will be discussed.