Abstract:

In order to solve the problem of insufficient research on the non-uniform mixed explosion characteristics of hydrogen leakage in the tunnel, the numerical simulation software Fluent was used to establish a tunnel model with the length, width and height of 60, 6.46 and 5.5 m, respectively. The non-uniform mixed explosion characteristics of hydrogen at the ignition time of 75 and 100 s and at ignition positions above and behind the vehicle were studied. The results show that the hydrogen leakage volume fraction field is not uniformly distributed in the tunnel scenario. After the explosion, the pressure wave reflects from the tunnel wall and propagates to the exit at both ends of the tunnel. In the process, the intensity of the pressure wave decreases continuously. The propagation characteristics of the blast wave formed by different ignition positions are obviously different. The influence of the explosion location on explosion overpressure is greater than hydrogen volume fraction. At the same time, the overpressure of ignition behind the vehicle is generally greater than that of ignition above the vehicle. The peak pressure at the position 2 m behind the vehicle can reach about 100 kPa. The rear ignition position within 2 m will cause serious injury or even death to the human body, and personnel within 4 m of the rear ignition position will suffer different degrees of injury.

Key words: tunnels, hydrogen vehicles, hydrogen leakage, non-uniform mixing, explosion characteristic