Experimental investigation of hydrogen release and ignition from fuel cell powered forklifts in enclosed spaces

Due to rapid growth in the use of hydrogen powered fuel cell forklifts within warehouse enclosures, Sandia National Laboratories has worked to develop scientific methods that support the creation of new hydrogen safety codes and standards for indoor refueling operations. Based on industry stakeholder input, conducted experiments were devised to assess the utility of modeling approaches used to analyze potential consequences from ignited hydrogen leaks in facilities certified according to existing code language. Release dispersion and combustion characteristics were measured within a scaled test facility located at SRI International's Corral Hollow Test Site. Moreover, the impact of mitigation measures such as active/passive ventilation and pressure relief panels was investigated. Since it is impractical to experimentally evaluate all possible facility configurations and accident scenarios, careful characterization of the experimental boundary conditions has been performed so that collected datasets can be used to validate computational modeling approaches.

► Benchmark library for accident scenarios during H2 indoor refueling was created.
► For tank blowdown warehouse H2 rapidly leans out once release finishes.
► Large plume ignition overpressures were observed in well-sealed warehouse scenarios.
► Passive venting reduced plume ignition overpressure; forced venting had no impact.
► Blowout panels are effective overpressure mitigation devices.