Evaluation of the blast-wave overpressure and fragments initial velocity for a BLEVE event via empirical correlations derived by a simplified model of released energy

When a pressure vessel filled with a liquid is involved in a fire, a variety of effects are to be expected. If the vessel is filled with LPG, a boiling liquid expanding vapour explosion (BLEVE) is one of the possible effects, although it does not always happen. Actually BLEVE is a complex phenomenon resulting from many factors which are hard to summarize into mathematical formulations or models. Nevertheless it could be useful in order to assess the consequences of a BLEVE, to have access to simplified models lying on physical basis. In this paper empirical correlations for blast-wave overpressure and fragments initial velocity are presented. The basic hypothesis that BLEVE is a phenomenon driven by the excess heat stored in the liquid (overheated liquid) is assumed and some thermodynamic approximations are introduced. Despite these approximations and the empirical formulation simplicity, the results accuracy is good.