Effect of the position and the area of the vent on the hydrogen dispersion in a naturally ventilated cubiod space with one vent on the side wall

Abstract

The design of ventilation system has implications for the safety of life and property, and the development of regulations and standards in the space with the hydrogen storage equipment. The impact of both the position and the area of a single vent on the dispersion of hydrogen in a cuboid space (with dimensions L x W x H = 2.90 × 0.74 × 1.22 m) is investigated with Computational Fluid Dynamics (CFD) in this study. Nine positions of the vent were compared for the leakage taking place at the floor to understand the gas dispersion. It was shown a cloud of 1% mole fraction has been formed near the ceiling of the space in less than 40 s for different positions of the vent, which can activate hydrogen sensors. The models show that the hydrogen is removed more effectively when the vent is closer to the leakage position in the horizontal direction. The study demonstrates that the vent height of 1.00 m is safer for the particular scenario considered. The area of the vent has little effect on the hydrogen concentration for all vent positions when the area of the vent is less than 0.045 m 2 and the height of the vent is less than 0.61 m. • The coupling effects of the height and the area of the vent on hydrogen diffusion were analyzed. • The average concentration of the local area of the cross-section for different vent positions was compared. • The flow for various vent positions in the horizontal direction was investigated.