Determining VCE Damage Zones Using the GAME Relations and Explosion Regions

Predicting potential consequences of Vapor Cloud Explosions (VCE’s) has always been an important issue in safety assessments, because of the devastating damage that this phenomenon can create on (petro chemical) production sites. Although the TNO Multi Energy Model has been recognized as one of the best methods to predict blast overpressures of vapor cloud explosions, its application has been complicated by the required expert knowledge to choose a blast strength category and percentage of confinement of the flammable cloud. In the GAME project (Guidance on Application of Multi Energy, a contract research project for HSE), TNO already developed a quantifiable method to derive the source strength of vapor cloud explosions, based on well-defined congestion area properties. Recently, this method has been extended and combined with dispersion models to derive a practical cloud coverage fraction, which is used to find the other important influencing parameter: the explosive mass of the cloud involved in the VCE. This so-called “explosion regions” method can be used to determine the potential damage zones on a realistic site, with various potential sources of releases and multiple congestion areas or “receptors”. The paper will give a full description of the calculation procedure used and will provide examples of its potential usage.