Hydrogen Deflagrations at Large Scale

摘要

Unconfined deflagrations of large volumes of hydrogen mixed with air have been studied inan open space to provide fundamental data needed for safety evaluations and validation ofcomputer models. The tests were performed in a 37 m 3 prismatic tent and in a 300 m 3 hemispherical tent that were filled with quiescent, homogenous mixtures ranging from 15%to 57% hydrogen by volume. To prevent confinement of the mass flow the mixtures werecontained by very thin plastic membranes that were cut just prior to igniting the mixture with a spark at the bottom center. As a reference some tests used a small amount of explosive todetonate a stoichiometric mixture to obtain the maximum energy release rate. Additional testsevaluated the effect on the blast wave behind a protective wall. The information collectedincludes flame front propagation monitored with ionization probes and fast thermocouples,the pressure-time histories of the resulting blast, and radiated heat obtained from thermal fluxsensors. The data show the effects of the ignition source, varying the hydrogen concentration,differences in the initial mixture volume (37 m 3 or 300 m 3), or a presence of a protective blastwall. The inclusion of obstacles at large scale within the combusting mixture and the rapidrelease of large quantities of hydrogen into the atmosphere will be studied.