A Study on a Modified Model for the Hold Time of a Clean Extinguishing Agent

Featured Application: The approach proposed in this paper can be applied to the fire safety field using total flooding Clean Extinguishing Agents. Accurate prediction of the hold time of a CEA can achieve reliable fire control and extinguishment, as well as prevent overdesign of the CEA system. When estimating the theoretical hold time of a Clean Extinguishing Agent (CEA), the hold time is predicted using a leakage exponent and leakage characteristics that are measured through an Enclosure Integrity Test (EIT). In particular, the leakage exponent n is conventionally applied as 0.5, but recently, a variable exponent has been applied through measurement (approximately 0.48 to 0.85). When variable n is applied, the hold time varies greatly depending on the size of n. Therefore, in this study, a modified theoretical model for the hold time of a CEA is proposed to improve the accuracy of the hold time depending on the leakage exponent n. The modified theoretical model applies a different analysis of the inflow and outflow volumetric flow, and the results enable a more accurate hold time prediction. The modified theoretical equation shows an improvement of up to 8.6% for outflow volumetric flow Vo and a maximum improvement of approximately 10.7% for hold time th.