| Abstract |
The deployment of hydrogen fuel cell buses has significantly contributed to the development of zero-carbon smart cities. However, hydrogen leakage incidents pose a significant threat to the safety and operational reliability of smart cities’ infrastructures. Numerous experimental and numerical studies have explored hydrogen leakage incidents. In contrast, certain aspects of the design parameters for ventilation systems in hydrogen fuel cell buses have not been sufficiently addressed in existing research. These design parameters play a critical role in the diffusion of hydrogen leakage and the potential consequences. This study analyzes the influence of various vent grid numbers (n) and leak orifice diameter (d1) on hydrogen diffusion patterns and emission efficiency. The following conclusion can be drawn: First, when hydrogen leaked from a 35 MPa storage cylinder, under the combined effects of the hydrogen storage compartment's structure and leakage point locations, two distinct gas exchange modes manifest at the vents: a) full inhale and full emission at the vents; b) air inhale in the upper part and emission in the lower part of the vents. Second, as the number of vent grids increases, the gas flow field inside the hydrogen storage compartment becomes more complex. The hydrogen emission efficiency (η) of the vent initially rises and then decreases. Third, hydrogen emission efficiency (η) models depend on the diameter of orifice (d1) and the number of vent grids (n) are established, providing valuable guidance for the design of vent parameters in hydrogen fuel cell buses. © 2025 Elsevier Ltd |
