Abstract
Ignition conditions and risks of ignition on a permissible value of hydrogen concentration in purge gas prescribed by HFCV-GTR were reevaluated. Experiments were conducted to investigate burning behavior and thermal influence of continuous evacuation of hydrogen under continuous purge of air / hydrogen premixed gas, which is close to an actual purge condition of FCV, and thermal evacuation of hydrogen. As a result of the reevaluation, it was shown from the viewpoint of safety that the permissible value of hydrogen concentration in purge gas prescribed by the current HFCV GTR is appropriate.
