Simulating the Opening of Fusible-Link-Actuated Fire Vents.
Simulating the Opening of Fusible-Link-Actuated Fire
Vents.
(3378 K)
Cooper, L. Y.
NISTIR 6227; 58 p. September 1998.
Fire Safety Journal, Vol. 34, No. 3, 219-255, April
2000.
Available from:
National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
Telephone:
1-800-553-6847 or 703-605-6000;
Fax: 703-605-6900.
Website: http://www.ntis.gov
Order number: PB98-177850
Keywords:
vents; building fires; compartment fires; computer
models; fire models; mathematical models; plunge tests
Abstract:
Model equations, suitable for general use in compartment
fire models, are developed to simulate the thermal
response to arbitrary fire environments of fusible-link
activated automatic fire vents. The method of analysis,
which focused on a prototype three-element link-mount
design, can be extended to arbitrary multiple-element
link mounts. Also, the equations for the prototype
three-element link mount are shown to include, and be
directly applicable to the problem of simulating the
response of single-element simply-supported links. A
method was developed to determine the values of the set
of parameters that characterize a particular multiple
link-mount design. This involves: 1) the measured
time-dependent thermal response of the link-mount design
to exposure in a plunge test, the type of test used to
characterize the thermal response of sprinkler links;
and 2) an analytical means of determining values of the
design parameters that yield an optimum fit between a
solution to the model equations and the temperature
data. The method takes account of the pre-fusing
solder-melting phase of fusible-link response. The
latter was shown to be very important for the link
design used in this study. The method was carried out
successfully for four plunge tests involving three
link-mount systems and one or two system/flow
orientations. In each case, the model equations, with
the determined values of the system parameters and model
equations were used successfully to simulate
previously-reported time of link fusing and vent
activation in a real fire environment.
