Simulation of detonation after an accidental hydrogen release in enclosed environments

An accidental hydrogen release in equipment enclosures may result in the presence of a detonable mixture in a confined environment. To assess the value of CFD techniques as a tool for damage assessment, numerical simulation of detonation was performed for two realistic scenarios. The first scenario starts with a pipe failure in an electrolyzer, resulting in a leak of 42 g of hydrogen. The second scenario deals with a failure in a reformer where 84 g of hydrogen is released. Dispersion patterns were first obtained from separate numerical simulation and detonative ignition was simulated by adding energy to a narrow region. Impulse values reached 600 Ns/m2 in the electrolyzer scenario while they reached 1100 Ns/m2 in the reformer. For all cases studied, the consequences are more serious in the reformer than the electrolyzer.