Citation

Hua JS, Fan WC, Liao GX. Fire Safety J. 1998; 30(3): 269-291.

Copyright

(Copyright © 1998, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

An experimental simulation was conducted to investigate the mechanisms of boilover phenomena in liquid pool fires with water sublayers. Observations of fire behavior and instrumentation of the local temperature history in oil/water layers revealed that a typical boilover process can be divided into three phases, i.e. a quasi-steady period, premonitory period and boilover period. Our attention was mainly focused on the premonitory phenomena of boilover, which is generally considered as one of the most important factors leading to the occurrence of boilover. Experimental examinations demonstrated that boilover only happens after the fuel/water interfacial temperature has reached the boiling point of water, and that it was the violent seething of water at the interface which brought about boilover. The emission of micro-explosion noise, one of the most prominent premonitory phenomena of boilover was examined in detail and found to be a result of the water boiling. The investigation on the premonitory micro-explosion noise of boilover illustrated that it is a possible means for early and remote detection of the occurrence of boilover in liquid pool fires. However, in a real fire situation, the micro-explosion is always contaminated by the environmental noise. Hence, pattern recognition techniques should be used to differentiate the micro-explosion noise from the unwanted background noise, and a predictive model should be used to evaluate the status of oil burning and predict the occurrence of boilover. A set of noise features and a practical model have been presented for these purposes.