A Study of Boilover in Liquid Pool Fires Supported on Water. Part II: Effects of In-depth Radiation Absorption

Experimental study of liquid fuel boilover behavior in normal and low pressures

“…Nomenclature: Alt, altitude in the experimental location (m); P, pressure in the experimental location (kPa); W, weight (g); MLR, mass loss rate (g/s); _ m ′ , mass loss rate (g/s); _ m ′′ , mass loss rate per square meter (g/m 2 s); _ m ′ b , mass loss rate during the boilover period mass loss rate (g/s); _ m ′ s , mass loss rate during the quasi-steady period (g/s); λ, thermal conductivity (kW/m · K); T f , flame temperature near the burner surface (K); T s , fuel surface temperature (K); D, diameter of fuel pan (m); h, convection coefficient (kW/m 2 · K); σ, Stephen Boltzmann constant; κ, effective absorption coefficient (m −1 ); T B , boiling point (K); T C , boilover critical temperature at the water-fuel interface (K); q ′′ s;c , nucleate boiling critical heat flux (W/m 2 ); t p , the time when boilover premonitory period starts (s); t b , the time when boilover occurs (s); ΔT excess , superheat temperature difference (K); χ, η, θ, percentage constant; C 1 , C 2 , A, B, k, constant; ΔH c , heat of combustion (kJ/mol); t, burning time (s); c p , specific heat capacity J/(kgK); T 0 , initial temperature of the water-fuel interface (K); h fg , evaporation latent heat (KJ/kg); R, thermodynamic constants; d, thickness of the waterfuel interface (m); ρ inter , density of the water-fuel interface (g/m 3 ); m inter , mass of the water-fuel interface (g); Rad, radiation (W/m 2 ); S, sound pressure level (dB); I Rad , intensity of the boilover based on radiation; I S , intensity of the boilover based on sound pressure level; I m , intensity of the boilover based on mass loss rate; P, pressure in the experimental location (kPa); T C , boilover critical temperature (K) Subscripts: N, normal pressure; L, low pressure Hua et al's 7 experimental examinations demonstrated that boilover only happens after the fuel-water interface temperature has reached the boiling point of water, and it can be the criterion of boilover premonitory period. Inamura et al 8 and Garo and Vantelon 9 found an important feature, which has been proved by many studies; the fuelwater interface temperature must be around 120°C, when a boilover occurs. Ferrero et al 10 carried out a series of large-scale pool fire experiments to improve knowledge of the thin-layer boilover phenomenon.…”

“…Hua et al's experimental examinations demonstrated that boilover only happens after the fuel‐water interface temperature has reached the boiling point of water, and it can be the criterion of boilover premonitory period. Inamura et al and Garo and Vantelon found an important feature, which has been proved by many studies; the fuel‐water interface temperature must be around 120°C, when a boilover occurs. Ferrero et al carried out a series of large‐scale pool fire experiments to improve knowledge of the thin‐layer boilover phenomenon.…”

Accidental burning of a fuel layer on a waterbed: a scale analysis of the models predicting the pre-boilover time and tests to published data

“…The attenuation factor (µy 0 ) exp −(µy 0 )y * may be evaluates as follows [18]: (i) the Bouguer number (µy 0 ) calculated for some fuels (data of [6,7,17,22,[28][29][30] are treated) varies approximately from 0.5 to 5; (ii) the term exp −(µy 0 )y * → 1 at the fuel surface (see Table 5). Therefore, (µy 0 ) exp −(µy 0 )y * ≡ O(1), so the main effect comes from the magnitude of N 0 .…”

Effects of Thin-Layer Boilover on Hydrocarbon Pool Fires

“…This time variation depends on each situation, varying approximately between 115 s for A lower than 1.5mm/m-2 and 80s for those cases in which A was greater than 1.5 mm/m-2. Inamura, Saito, and Tagavi (1992) proposed a model to predict the time to boilover onset, and published several experimental data. Their model could not be applied to the results of this study because of the lack of several data required to apply it (temperature of fuel at the free surface).…”

“…Although there are some papers dealing with large pool-fires (for example, the research developed by Koseki, Kokkala, and Mulholland, 1991, or more recently, the paper by Broeckmann and Schecker, 1995) they are mainly focused on both the boilover mechanism and hot zone formation in deep fuel layers, and large fires involving a Downloaded by [Universite Laval] at 00:05 27 December 2014 thin-layer boilover process are still lacking and very scarce. Other authors (Inamura, Saito, and Tagavi, 1992) present one-dimensional models to predict the time required for the water sublayer to start to boil; however, these studies are often quite different and a comparative analysis cannot be made. 111 this paper a set of large scale pool-fires of different diameters are described.…”