Influence of excess fuel from timber lined compartments. (28th February 2020)

• Record Type: Journal Article
• Authors: Bartlett, Alastair; Law, Angus
• Is Part Of: Construction & building materials. Volume 235(2020)
• Publication Date: 2020-02-28
• Subjects: Timber -- Fire -- External flaming -- Fire spread -- Global Equivalence Ratio -- Excess fuel factor; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2019.117355
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Timber lined compartments have the potential for greater external flaming due to additional fuel loading. The Global Equivalence Ratio is discussed as a means to quantify the fuel exiting the compartment. Recent compartment fire experiments with exposed timber are analysed, and the Global Equivalence Ratios compared. Global Equivalence Ratio is found to increase as a function of the area of exposed timber. Abstract: External fire spread is a key risk faced by engineers in the design of buildings. This can be quantified by heat flux to an exposed surface, which is dependent on the conditions in the external fire plume. Introducing additional fuel in the form of exposed timber surfaces is shown to increase the energy released by external flaming, as defined by an excess fuel factor or Global Equivalence Ratio (GER). This paper presents a review of three recent experimental series exploring the effects of exposed timber on compartment fire dynamics, and uses experimental data to calculate the GER for each experiment. When combustion efficiency was assumed equal to one, Global Equivalence Ratios were found to range from 0.58 to 3.00; these corresponded to a compartment with a single exposed timber surface and a compartment with three exposed timber surfaces. A "burning factor" has been introduced to as a possible method to relate GER to the properties of the compartment. It is found that a relatively good correlation (R 2 > 0.9) is achieved between burning factor and GER when only the compartment surfaces are burning, but that the correlation does not hold when other fuel load is also burning within the compartment.