Assessing Halon Alternatives for Aircraft Engine Nacelle Fire Suppression.
Assessing Halon Alternatives for Aircraft Engine Nacelle
Fire Suppression.
(772 K)
Grosshandler, W. L.; Presser, C.; Lowe, D. L.; Rinkinen,
W. J.
Journal of Heat Transfer, Vol. 117, 489-494, May 1995.
Keywords:
halons; halon alternatives; halon 1301; aircraft
engines; nacelle fires; fire suppression; methodology;
nitrogen; jet engines; thermodynamic properties
Abstract:
A coaxial turbulent spray burner was built to evaluate
the relative effectiveness of different chemicals for
suppressing fires in a jet engine nacelle. The fire
suppressant of current choice, halon 1301 (CF3Br), must
be replaced because of its detrimental effect on the
ozone layer. The alternatives being considered lack the
chemical activity of CF3Br, so that the ability of the
agents to mix into the flame convectively and to absorb
heat is critical to their success. An agent delivery
system was designed to inject the desired amount of
material into the air upstream of a fuel nozzle and to
control the agent injection rate through variation of
the storage pressure and the duration of time that a
solenoid valve remains open. The influence of air
velocity, fuel flow, and injection period on the amount
of nitrogen required to extinguish a jet fuel spray
flame is discussed. The effectiveness of eleven
different fluorocarbons, hydrofluorocarbons, and
hydrochlorofluorocarbons is compared to that of halon
1301. The alternatives required 1.7 to 2.3 times the
amount (on a mass basis) of CF3Br to extinguish the
spray flame, with HCFC-22 being the most efficient and
FC-31-10 the least.
