Ignition of 4.8-12 Vol% Hydrogen Air Mixtures by Platinum-Coated Ceramic Particles

The accumulation of hydrogen during a hypothetical accident poses a danger to nuclear power plants based on light-water reactors (LWR). Currently, flameless hydrogen oxidation systems - or recombiners - are widely used to neutralize this danger at nuclear power plants. However, when heated to a high temperature during the oxidation of hydrogen, catalytic recombiner elements can become the sources of flame, which complicates the course of emergency. The article presents an experimental study connected with the ignition of 4.8-12 vol% hydrogen air mixtures caused by the particles of platinum-covered ceramics. As well as confirming the possibility that catalytic recombiner particles may initiate ignition, the performed study determines the temperature and concentration limits of this phenomenon. Based on the data obtained in the course of the experiment, the delay time of the mixture ignition was estimated.