Mathematical modelling of BLEVE accidents

A BLEVE (Boiling-Liquid Expanding-Vapour Explosion) represents one of the most dangerous accidents which can occur during the handling or storage of a low-boiling liquid. It consists in the explosive expansion of the liquid when suddenly exposed to a non-equilibrium thermo-dynamic condition. In most of the cases this means that the liquid is at a temperature higher than the boiling temperature at a newly established pressure. The expansion of the vapour produced by the evaporation can be so fast that a pressure wave is generated, possibly leading to damages to people, structures and facilities. Many studies have been conducted to estimate the consequences of such an event (Prugh, 1988; Crowl and Louvar, 1990; CCPS 1994, 2000; Lees 2005) while less effort has been devoted to studying the dynamics of the accident before the occurrence of the explosion. Works by previous authors (Reid, 1979; Birk and Cunningham, 1994; Birk, 1995; Birk and Cunningham, 1996), describe the different phenomena involved in the process, but a comprehensive model of the accident and, above all, a simple tool describing the evolution of the physical processes simultaneously occurring during the accident, are still missing. In the present paper the results of a mathematical description of the phenomenon are presented and compared with experimental data reported in the literature