PNNL’s Hydrogen Safety ProgramWhy Hydrogen Fuel?Hydrogen – A Clean, Flexible Energy CarrierWhy Fuel Cells? H2@scale: Enabling Affordable, Reliable, Clean, and Secure Energy Across SectorsUpward trend with global fuel cell shipments 2018 U.S. Snapshot More details in Slides

Introduce the Hydrogen Safety Panel (HSP)Introduce key hydrogen safety resources that are availableOpen discussion on your hydrogen safety issues and needsExplore how the HSP can help the safe rollout of hydrogen and fuel cell technologiesIdentify projects that could utilize the HSP for impactful safety reviews

The ignition of a hydrogen-air mixture that has engulfed a typical set of ambient vaporizers (i.e., an array of finned tubes) may result in a deflagration-to-detonation transition (DDT). Simplified curve-based vapor cloud explosion (VCE) blast load prediction methods, such as the Baker-Strehlow-Tang (BST) method, would predict a DDT given that typical ambient vaporizerswould be rated as medium or high congestion and hydrogen is a high reactivity fuel (i.e., high laminar burning velocity).

VIII.6  Hydrogen Safety Panel, Safety Knowledge Tools and First Responder Training Resources

Ammonia and hydrogen represent opposite ends of the spectrum with regard to the potential blast loading resulting from an accidental vapor cloud explosion (VCE), although many in industry have expressed doubts as to whether either of these fuels actually pose a VCE hazard. Ammonia is some-times discounted as a VCE hazard due to the perceived difficulty in igniting an ammonia-air mixture and/or because of its low laminar burning velocity. Hydrogen is sometimes discounted as a VCE hazard due to the ease with which a hydrogen-air mixture can be ignited and/or because of its buoy-ancy.

VIII.6  Hydrogen Safety Panel, Safety Knowledge Tools and First Responder Training Resources

In collaboration with Parker Hannifin Corporation, the Fire Safety Branch of the FAA conducted testing to evaluate the effects of three potential failure conditions of hydrogen proton exchange (or polymer electrolyte) membrane fuel cell stacks supplied by Nuvera Fuel Cells. The three conditions examined were a loss of coolant to the stack, short circuit, and a crossflow condition.

VIII.6  Hydrogen Safety Panel, Safety Knowledge Tools and First Responder Training Resources

Fuel Cell Basics and ApplicationsProperties of HydrogenPrimary Codes and StandardsFundamental Safety ConsiderationsHydrogen Safety ResourcesFirst Responder Training ResourcesConcluding Thoughts

The purpose of this guide is to provide basic background information on hydrogen technologies.It is not intended to be a comprehensive collection of hydrogen technologies safety information.