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Applicability of Correlations Between the Species Formation and the Global Equivalence Ratio in a 1/2-Scaled ISO Compartment With Nongaseous Fuel.


pdf icon Applicability of Correlations Between the Species Formation and the Global Equivalence Ratio in a 1/2-Scaled ISO Compartment With Nongaseous Fuel. (890 K)
Wieczorek, C. J.; Vandsburger, U.; Lattimer, B.; McKay, C.

Fire Safety Science. Proceedings. Sixth (6th) International Symposium. International Association for Fire Safety Science (IAFSS). July 5-9, 1999, Poitiers, France, Intl. Assoc. for Fire Safety Science, Boston, MA, Curtat, M., Editor(s), 965-976 pp, 2000.

Sponsor:

National Institute of Standards and Technology, Gaithersburg, MD

Keywords:

fire research; fire safety; fire science; compartments; experiments; compartment fires; global equivalence ratio

Abstract:

Lifestyle developments on the global scale which manifest themselves in increased travel, increased elderly populations in assisted care facilities, and urbanization require increased attention to fire safety in dense occupation environments. Statistics spanning decades have shown that the key factor in fire fatalities is CO inhalation, termed loosely "smoke inhalation," not only in the fire enclosure but in areas remote from the flames. The current study was geared at developing correlations to relate the levels of CO, CO2, and UHC produced and the amount of O2 depleted during compartment fires to the burning compartment global equivalence ratio (GER). This is a first step in a study, which will include a study of fire products transported to adjacent enclosures, and the development of engineering correlations. Tests were conducted in a 1/2-inch scale ISO compartment with fully scaled door openings, using n-hexane pool fires within the center of the compartment. Two fire scenarios were simulated, a fully and partially opened door, by varying the door width. The results, in form of concentrations of the fire products as a function of equivalence ratio (corrected for various transport times) were compared with previous hood and special configuration compartment studies. The present work indicated that the residence time of the gases within the compartment has an effect on both the carbon monoxide levels and the carbon dioxide levels. The narrow door configuration yields the lowest CO levels and the highest CO2 levels. This is expected since the residence time of the gases within the narrow door (19.5 sec) is more than twice that of the baseline door (9.3 sec), therefore the there is more time for the CO to oxidize to CO2. The unburned hydrocarbon levels are not effected by the residence times in this study since UHC's have a higher reaction rate than CO under the present fire condition. Therefore, the levels of UHC's will be dependent only on the availability of free oxygen.