Modelling absorption and dilution of unconfined releases of hazardous gases by water curtains or monitors

摘要

OSHA Process Safety Management guidelines suggest that a facility operator investigate and document a plan for installing systems to detect, contain, or mitigate accidental releases if such systems are not already in place. In addition, proposed EPA 112(r) regulations would require such analysis. This paper illustrates how mathematical modeling can aid such an evaluation and describes some recent enhancements of the HGSPRAY model: (1) adding algorithms for modeling NH(sub 3) and LNG mitigation; (2) modeling spraying of releases with fire water monitors encircling the point of release; (3) combining wind tunnel modeling with mathematical modeling; and (4) linking HGSPRAY and BEGADAS. Case cases are presented as examples of how HGSPRAY can aid the design of water spray systems for initiation of toxic gases (e.g., BF, NH,) or dilution/dispersion of flammable vapors (e.g., LNG).