Simplified kinetics for simulation of detonation waves in realistic accident scenarios.

摘要

Hydrogen detonations are potentially a serious safety risk if hydrogen distribution installations are to become wide spread. Additionally, fundamental understanding of the circumstances that lead to detonation is lacking. Hydrogen is known to have three explosion limits, and its kinetics are characterized by chain-branching. A three-step chemical kinetics scheme is analyzed that includes initiation, chain-branching and termination. It can be used to study detonations, their stability and the deflagration to detonation transition. The analysis considers a steady one-dimensional ZND wave model; it is based upon the assumption that initiation is slow. Analytical results show that the one-dimensional structure results in a less complete burn than the cellular structure that normally occurs as obtained in numerical simulations. Additionally, numerical simulations are performed for realistic accident scenarios following a hydrogen leak in an enclosure using one-step chemistry. Results show that even a small amount can lead to high impulse values on the enclosure walls.