Experimental Study of the Effects of Fuel Type, Fuel Distribution and Vent Size on Full-Scale Underventilated Compartment Fires in an ISO 9705 Room.
Experimental Study of the Effects of Fuel Type, Fuel
Distribution and Vent Size on Full-Scale Underventilated
Compartment Fires in an ISO 9705 Room.
(9188 K)
Lock, A.; Bundy, M.; Johnsson, E. L.; Hamins, A.; Ko, G.
H.; Hwang, C.; Fuss, P.; Harris, R. H., Jr.
NIST Technical Note 1603; NIST TN 1603; 167 p. October
2008.
Keywords:
compartment fires; fuels; room fires; fuel distribution;
vents; experiments; ventilation; doorways; burners; heat
release rate; gas chromatography; gas samples; storage;
soot; thermocouples; heat flux; data processing;
uncertainty; temperature; mixture fracture; carbon
balance method; hydrocarbon fuels; combustion
efficiency; liquid fuels; solid fuels; fire models;
field models
Abstract:
This report describes new full-scale compartment fire
experiments, which include local measurements of
temperature, heat flux and species composition, and
global measurements of heat release rate and mass
burning rate. The measurements are unique to the
compartment fire literature. By design, the experiments
provided a comprehensive and quantitative assessment of
major and minor carbonaceous gaseous species and soot at
two locations in the upper layer of fire in a full scale
ISO 9705 room. Fire protection engineers, fire
researchers, regulatory authorities, fire service and
law enforcement personnel use fire models (such as the
NIST Fire Dynamics Simulator, FDS for design and
analysis of fire safety features in buildings and for
post-fire reconstruction and forensic applications. Fire
field models have historically showed limited ability to
accurately and reliably predict the thermal conditions
and chemical species in underventilated compartment
fires. Formal validation efforts have shown that for
well ventilated compartment fires, with the exception
perhaps of soot, field models do quite well in
predicting temperature and species when experimental
uncertainty is accounted for. Inaccurate predictions of
incomplete burning and soot levels impact calculations
of radiative heat transfer, burning rates, and estimates
of human tenability. High-quality (relatively low,
quantified uncertainty) measurements of fire gas
species, temperature and soot from the interior of
underventilated compartment fires are needed to guide
the development and validation of improved fire field
models. The experimental results provided in this
report are the continuation of a long-term National
Institute of Standards and Technology (NIST) project to
generate the data necessary to test our understanding of
fire phenomena in enclosures and to guide the
development and validation of field models by providing
high quality experimental data. The experimental plan
was designed in cooperation with developers of the NIST
FDS model to assure that the measurements would be of
maximum value. Advanced development of FDS and other
field models is extremely important, since it will lead
to improved accuracy in the prediction of
underventilated burning, typical of fire conditions that
occur in structures. Improving models for
under-ventilated burning will foster improved prediction
of important life safety and fire dynamic phenomena,
including fire spread, backdraft, flashover, and egress
involving the presence of toxic gas and smoke), which
are critically important for application of fire models
for fire safety.
