Conclusion
In view of the environmental friendliness, low boiling point and low
toxicity of CF3I, it could be a potential Halon
substitute for fire-extinguishing agent in aircraft. In this paper, DFT
calculations were performed to theoretically investigate the thermal
decomposition and fire-extinguishing mechanism of CF3I,
which suggest that CF3I and its decomposition products
can further react with active OH· and H· radicals existed in flame
through various pathways. Remarkably, through DFT calculation and
reaction kinetics analysis, the fire-extinguishing radicals
CF3· and I· are more easily generated during the
interaction between CF3I and flame, which can react with
the active OH· and H· radicals to achieve the purpose of rapidly
extinguishing fire.
To explore its actual fire-extinguishing effect, we also measured the
FEC of CF3I on methane-air flame. The experimentally
measured FEC of CF3I on methane-air flame is 3.42vol%,
which is lower than those of three HFCs and HFO-1336mzz(E), and is
comparable to that of Halon 1301. Due to the pronounced
fire-extinguishing performance, environmental friendliness, and
promising thermal stability and storability, the CF3I
agent is a recommendable candidate for Halon, which is worthy of further
evaluation and confirmation of its practical applications in fire
suppression process.