Storage and Discharge Characteristics of Halon Alternatives.
Storage and Discharge Characteristics of Halon
Yang, J. C.; Cleary, T. G.; Vazquez, I.; Boyer, C. I.;
King, M. D.; Breuel, B. D.; Grosshandler, W. L.; Huber,
M. L.; Weber, L.
Alliance for Responsible Atmospheric Policy; U.S.
Environmental Protection Agency; Environment Canada;
United Nations Environment Programme; U.S. Department of
Agriculture. Stratospheric Ozone Protection for the
90's. 1995 International CFC and Halon Alternatives
Conference and Exhibition. Proceedings. October 21-23,
1995, Washington, DC, 594-603 pp, 1995.
Sponsor:Federal Aviation Administration, Washington, DC
halon alternatives; aircraft fires; dry bays; discharge;
halons; pipes; sprays; thermophysical properties
Three important issues regarding the use of halon
alternatives for in-flight fire protection applications
were studied as part of the current halon alternative
research program at the National Institute of Standards
and Technology (NIST): (1) the conditions inside the
vessel at different ambient temperatures before
discharge, (2) the discharge of the contents into a
confined space, and (3) the distribution of the
agent/nitrogen mixture in piping systems. The first
issue addresses the resultant pressure inside the vessel
before discharge. Such information dictates the vessel
structural integrity and subsequent discharge behavior
of the agent/nitrogen mixture. The second deals
specifically with military aircraft dry bay fire
protection, and the third concerns general (commercial
and military) aircraft engine nacelle fire protection
applications. To establish the internal vessel
conditions, the effects of fill density, initial
nitrogen pressure, and ambient temperature were studied.
For the discharge of agent/nitrogen mixture into a
confined space, the effects of vessel geometry, initial
nitrogen pressure, fill density, initial vessel
temperature, discharge mechanism, discharge orientation,
and orifice size were examined. For the distribution of
agent/nitrogen mixture in piping systems, the effects of
initial nitrogen pressure, fill density, initial bottle
temperature, and piping geometries (sudden pipe
expansion and contraction, different piping diameters,
tees, and elbows) on the two-phase flow behavior were
explored. Experimental results and model predictions
will be presented and discussed for each issue.