Numerical investigation of hydrogen detonation suppression with inert particle in pipelines

Abstract To numerically study the propagation process of detonation of H 2 O 2 N 2 mixture and explosion suppression process with inert particle explosion, this paper developed theoretical models for detonation of one-dimensional combustible system and explosion suppression with inert particle based on two-fluid model by considering elementary chemical reactions, shock wave as well as momentum and energy transport effects between gas and particle phases. Meanwhile, Riemann invariant was derived on the basis of the one-dimensional problem. Gas and particle phase equations were solved using TVD and MacCormack schemes, respectively, Stiffness of equations was addressed by time-splitting scheme. Runge-Kutta method was employed to solve chemical reaction. Based on these equations, numerical method was constructed to analyze detonation of H 2 O 2 N 2 mixture and explosion suppression process. The results showed that under certain initial conditions, high-temperature fireball induced shock wave formed and subsequently developed into detonation. After loading suitable concentration of inert particle into a certain explosion suppression area, combustion flame decelerated due to the transfer of momentum and energy between gas and particle phases, and distance between shock wave and flame increased gradually to lose energy support. Meanwhile, inert particles also absorbed shock wave energy. The two effects proceeded simultaneously and mutually fed back to rapidly attenuate shock waves, thereby successfully suppressing explosion. The inert particle density, concentration and diameter were critical important to explosion suppressant. Besides the product, reactant and some mainly radical components affected the detonation velocity. Especially, OH radicals were present almost only in the combustion reaction zone, indicating their significant impact on the chemical reaction rates.