Maximizing the retention time of inert gases used in fixed gaseous extinguishing systems

The problem of fire safety rooms protected by fixed gaseous extinguishing system is discussed. The structure and parameters of Fixed Extinguishing System-gaseous (FES-gaseous) has been characterized and the characteristics of extinguishing gases applicable in these systems have been described. On the basis of literature including the analysis of known models of determining the retention time the factor defining the length of the retention time have been determined. The density of extinguishing gas has been indicated as the value of a large potential for extending the retention time. It was found that when the difference between the density of gas inside the protected space and the ambient air tends towards zero then the maximum values in the retention time are achieved. Based on the research it was found that the selection of the composition of the extinguishing gas maximizes the retention time. Extinguishing gases with densities close to air density provide the retention times at least several times longer than extinguishing gases currently use in the fire protection. Performed experiments may allow preparation and validation of numerical method for evaluation of retention time in complex geometries.