Calculating the Explosion Energy of a BLEVE Using Exergy Analysis

Following the work of Crowl on calculating the energy of explosions using exergy (thermodynamic availability), we examine the explosion energy of boiling liquid, expanding vapor explosions (BLEVEs). A number of investigators have proposed schemes for calculating the maximum work that a BLEVE can perform on its surroundings. Their proposed evaluation schemes yield varying results because they depend significantly on the precise specification of the thermodynamic path taken by the vaporizing, expanding mass. We demonstrate how to evaluate the maximum theoretical work associated with a BLEVE as a function of the fluid's thermodynamic properties and its equation of state. We consider two specific forms of BLEVE: nonreactive and reactive (combusting) fluids. Finally, we give numerical examples to compare the availability of a BLEVE with some of the proposed schemes suggested by others. The advantage of using exergy analysis to evaluate the maximum work of a BLEVE is the rigorous and unambiguous definition for exergy.