Experimental Validation and Effectiveness Analysis of N 2 , EG, and NaCl in Extinguishing Pool-Style Combustion of Sodium Metal

To systematically analyze the effectiveness of sodium-nonreactive fire extinguishing agents in suppressing pool fires of molten sodium, this study examines the energy variations induced by N2, EG, NaCl, and EG-NaCl in the reaction zone of pool fires based on the energy conservation theory. Results indicate that N2 primarily suppresses fires by reducing oxygen concentration to diminish oxidation heat release, coupled with its cooling effect. EG forms a porous carbon layer on the sodium pool surface to isolate external high-temperature heat flow and reduce the fuel evaporation rate, achieving fire extinction. NaCl combines isolation and cooling functions, but its molten layer fails to stably cover the sodium pool due to higher density than liquid sodium, resulting in limited isolation efficacy. The EG-NaCl composite powder effectively addresses EG’s lack of heat absorption capability and NaCl’s poor isolation performance. Experimental results validate the above analyses.