Effect of obstacle location on hydrogen dispersion in a hydrogen fuel cell bus with natural and mechanical ventilation

Hydrogen leakage in hydrogen fuel cell buses can cause danger to the public. Cuboid space finite element models are established to study the effect of obstacle positions on the hydrogen dispersion behaviour under no ventilation, natural ventilation and mechanical ventilation by monitoring the hydrogen concentration along the line and on the iso-surface. The effect of the obstacle on the hydrogen dispersion behaviour is enhanced with the reduction of the distance from the obstacle to the leakage location. In the space with no ventilation, the effect of the obstacle on hydrogen dispersion varies with the dispersion phase. In the naturally ventilated space, the concentration of hydrogen on the side with an obstacle is higher than that on the side without any obstacles; thus, the presence of the obstacle is not conducive to hydrogen exiting the compartment. In the mechanically ventilated space, the effect of the obstacle on hydrogen dispersion is more pronounced. Specifically, the hydrogen concentration on the side with no obstacles is 2–3 times that on the side with an obstacle, so the obstacle is conducive to hydrogen exiting. The obstacle is recommended to be in the focus of the related hydrogen leakage behaviour study.