Hydrogen Behavior: Unintended Releases
Sandia National Laboratories has been working with stakeholders and original equipment manufacturers (OEMs) to develop scientific data for use in creating risk-informed hydrogen codes and standards for the safe operation of indoor hydrogen fuel-cell forklifts. An important issue is the possibility of an incident inside a warehouse or other enclosed space, where an unintended release of hydrogen from the forklift vehicle could occur. For such scenarios, a combined experimental and modeling program has been used to study the release and dispersion of gaseous hydrogen from the vehicle and to analyze the behavior of the ignitable hydrogen cloud inside the warehouse enclosure. We have studied the overpressure arising as a result of ignition and subsequent deflagration of the hydrogen cloud within the warehouse for different ignition delay times and ignition locations. Our work has considered both ventilated and unventilated warehouses. Our experimental results and validated models guide new codes and standards development for the safe operation of indoor hydrogen forklift vehicles.