Computational Fluid Dynamics Simulations of Hydrogen Jet Fires inside a Tunnel

Abstract

Compared with the hydrogen jet fire from a pressure vessel in an open space, the hydrogen jet fire inside a tunnel has a different kind of risk because of the semi-enclosed space. In this study, computational fluid dynamics (CFD) simulations of the hydrogen jet fire from a hydrogen transport vehicle inside a tunnel were carried out. Several different factors, such as hydrogen leakage rate, leakage area, longitudinal ventilation, transverse ventilation and the volume of the tunnel, were considered to analyze the influence on the temperature and diffusion of hydrogen inside the tunnel during the jet fire. The results show that compared with an open space, the hazards of the hydrogen jet fire inside a tunnel lie in not only high temperature but also the accumulation of hydrogen, which may pose a secondary disaster inside the tunnel. In order to control the hazard and avoid a secondary disaster after the hydrogen jet fire happened, enough longitudinal and transverse ventilation is necessary inside the tunnel. Keywords—computational fluid dynamics simulations; hydrogen jet fire; tunnel fire; dangerous chemical transport