Abstract: To explore the endothermic and cooling efficiencies of different gaseous fire extinguishing agents during the release process, a 1 m×1 m×1 m fire extinguishing test platform was set up to conduct gaseous fire extinguishing agent spraying tests. The endothermic capacities of typical gaseous fire extinguishing agents (Halon 1301, HFC-227ea, perfluorohexanone and 2-BTP) on the gas storage cylinders, nozzles and protected objects throughout the release process were analyzed, as well as the impact of the initial temperature of the protected objects on the cooling efficiencies of the new clean gaseous fire extinguishing agents (perfluorohexanone and 2-BTP). Test results shows that Halon 1301 and HFC-227ea vaporized during the transmission process, therefore poor cooling performance was observed. Whereas for 2-BTP and perfluorohexanone, no phase change in the pipeline results in quick vaporization and heat absorption when the agent droplets reaching the surface of the target. Hence, the two agents exhibit high cooling effectiveness than others. Overall, the cooling efficiency ranking for the four agents is 2-BTP＞perfluorohexanone＞HFC-227ea＞Halon 1301. Compared with perfluorohexanone, 2-BTP not only allowed the largest temperature reduction on the target but also led to a slow temperature recovery after the agent was discharged. This is because 2-BTP absorbs the largest amount of heat when using the same amount of agents. Therefore, the choice of fire suppression agents and corresponding system design is critical to improve cooling efficiency and fire suppression performance.

Key words: 2-BTP, perfluorohexanone, gaseous fire suppression agent, cooling performance