Binary CF3Br- and CHF3-inert flame suppressants: Effect of temperature on the flame inhibition effectiveness of CF3Br and CHF3

A numerical investigation with detailed chemistry and transport was conduct ed on the inhibition effectiveness of binary halogenated suppressant and in ert gas mixtures. Computational results demonstrate that while positive syn ergism persists between CF3Br and inert gases, little or negative synergism exists between CHF3 and inert gases. These synergistic effects are attribu ted to the sensitivity of flame inhibition effectiveness of the chemical su ppressant, in that while the inhibition effectiveness of CF3Br is enhanced at lower flame temperatures, it remains relatively unchanged with CHF3 over the examined temperature range. The temperature sensitivity of CF3Br inhib ition effectiveness is a result of enhanced catalytic inhibition cycles as the flame temperature decreases. It is also demonstrated that water vapor t ends to diminish the flame inhibition effectiveness of CHF3. (C) 1999 by Th e Combustion Institute.