Numerical investigation on the effects of smoke barriers on hydrogen dispersion in a full-scale underground garage

Safety issues such as unintentional hydrogen releases in confined spaces limit the widespread promotion of hydrogen terminal applications, especially hydrogen fuel cell vehicles (HFCVs). This paper aims to perform a systematical numerical investigation of hydrogen leakage and dispersion in a full-scale underground garage, and the effects of smoke barriers are also considered. Four sets of smoke barriers with different heights, 0.1–0.7 m with 0.2 m increment, are installed below the ceiling, and three different partition types are set. The results show that smoke barriers can reduce flammable areas but increase local hydrogen concentrations. As the height of the smoke barrier increases, its obstruction to hydrogen dispersion on the ceiling is enhanced, making it easier for hydrogen to accumulate in the area and increasing the hydrogen cloud thickness. The hydrogen concentration in the horizontal direction showed a stair-like stratification phenomenon and decreased with increasing horizontal distance from the leak point. When the height of the smoke barrier is below 0.7 m, a larger partition area is safer. This study can provide new insights into the accidental hydrogen leakage and dispersion issues in confined spaces, in particular the effects of smoke barriers, and lay a theoretical foundation for the safety design of enclosed garages for HFCVs.