Dispersion of hydrogen leaking from a hydrogen fuel cell vehicle

Hydrogen will be an important energy carrier in future energy supplies. Since hydrogen is portable and has a reasonable energy density, hydrogen will be especially important for transportation. However, a vital issue for hydrogen fuel cell vehicles (HFCV) is the safety concerns when hydrogen is leaking from a damaged vehicle after an accident. This paper describes simulations of the use of a portable blower to disperse hydrogen around a leaking vehicle when the blower is in front of the vehicle so that first responders can safely approach the vehicle. The simulations compare well with previous experimental results for a blower in front of the vehicle. The calculations predict the hydrogen concentration distributions around a vehicle for various scenarios to find the most effective solution to provide safe hydrogen levels around the vehicle. The models show that a ground effect blower with the diffuser flush to the floor more effectively removes most of the hydrogen to create a safety envelope around the vehicle. The results also show that the first responders should not approach the vehicle from the side opposite the blower where the hydrogen concentrations would still be close to the lower flammability limit even with a blower.