Towards an Exergy-Based Explosion Energy Model for Boiling-Liquid Expanding-Vapor Explosions
A boiling liquid, expanding vapor explosion (BLEVE) occurs when a pressure vessel containing a superheated liquid undergoes a catastrophic failure, resulting in a violent vaporization of the liquid. The exposure of a pressure vessel to a fire is a classic scenario that can result in a BLEVE. The thermomechanical exergy of a pressure vessel’s contents provides — by definition — an upper bound on the work that can be performed by the system during the explosion. By fixing the values of ambient pressure and temperature (i.e., the dead state), exergy can be interpreted as another thermodynamic property. This rigorous and unambiguous definition makes it ideal to estimate the maximum energy of explosions. The numerical value of exergy depends on the definition of the dead state. In this paper we examine the effect of different definitions for the dead state on the explosion energy value. We consider two applications of this method: the contribution of the vapor head-space to the explosive energy as a function of the fractional liquid fill of the vessel, and the effect of the vessel burst pressure.