A study on relationship between burning rate and flame height of internal fire whirls in a vertical shaft model

The fire whirl generated by burning a pool fire in a vertical shaft with a single corner gap of appropriate width was studied using a high-speed camera. A 7-cm diameter pool propanol fire with heat release rate 1.6 kW in free space was burnt inside a 145-cm tall vertical shaft model with gap widths lying between 2 cm and 16 cm. The flame height was between 0.25 m and 0.85 m for different gap widths. Photographs taken using a high-speed camera at critical times of swirling motion development were used to compare with those taken using a normal camera. From the experimental observations on flame swirling by a high-speed camera, stages for generating the fire whirl were identified much more accurately. Two flame vortex tubes moving over the horizontal burning surface of the liquid pool were observed. Based on these observations a set of more detailed schematic diagrams on the swirling motion was constructed. From the observed flame heights under different gap widths and using three assumptions on the variation of air entrainment velocity with height, an empirical expression relating the burning rate with flame height and the corner gap width was derived from the observation with high-speed camera. The correlation expression of the burning rate of the pool fire obtained would be useful in fire safety design in vertical shafts of tall buildings.

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Dependence of flame height of internal fire whirl in a vertical shaft on fuel burning rate in pool fire

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2017.04.108 ◽

2017 ◽

Vol 121 ◽

pp. 712-720 ◽

Cited By ~ 4

Author(s):

W.K. Chow ◽

J.F. Dang ◽

Y. Gao ◽

C.L. Chow

Keyword(s):

Burning Rate ◽

Pool Fire ◽

Flame Height ◽

Vertical Shaft ◽

Fuel Burning ◽

Fire Whirl

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Effects of pool size and spacing on burning rate and flame height of two square heptane pool fires

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2019.01.111 ◽

2019 ◽

Vol 369 ◽

pp. 116-124 ◽

Cited By ~ 10

Author(s):

Huaxian Wan ◽

Zihe Gao ◽

Jie Ji ◽

Yongming Zhang ◽

Kaiyuan Li ◽

...

Keyword(s):

Burning Rate ◽

Pool Size ◽

Flame Height ◽

Pool Fires

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Numerical Simulation of Fire in a Gasoline Storage Tank in Reduced-Scale

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.372.11 ◽

2017 ◽

Vol 372 ◽

pp. 11-20

Author(s):

Renan Spilka Miranda ◽

Maria Luiza Sperb Indrusiak ◽

Felipe Roman Centeno

Keyword(s):

Numerical Simulations ◽

Burning Rate ◽

Real Data ◽

Type A ◽

Anhydrous Ethanol ◽

Flame Height ◽

Small Scale ◽

Mass Burning Rate ◽

Fuel Mass ◽

Type C

With the increasing demand for energy and fuels in Brazil, the storage of liquid fuels in multiple tanks is becoming much more usual, posing challenges from the point of view of fire safety. To study this type of phenomenon and to evaluate its possible causes, detecting failures such as ones in design and erection of storage systems or in detection and protection equipment, numerical simulations are performed based on real data. This work presents numerical simulations of a small-scale tank for gasoline storage, based on an experimental study reported in literature. The present research shows results related to temperature in the region adjacent to the tank on fire, fuel mass burning rate, heat release rate and average flame height. Comparisons are made between numerical and experimental results, as well as with available literature results for similar conditions. In addition to gasoline type C (which has anhydrous ethanol in its composition), also gasoline type A (anhydrous ethanol free) is considered. The results obtained for simulations with gasoline type A presented better agreement with literature data than those for gasoline type C, the differences being due to the variable composition of the type C fuel. For example, the reported fuel mass burning rate for gasoline in literature is 0.045 kg/(m2∙s), while the present simulations provided values of 0.038 kg/(m2∙s) for type C and 0.047 kg/(m2∙s) for type A.

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A study of correlation between flame height and gap width of an internal fire whirl in a vertical shaft with a single corner gap

Indoor and Built Environment ◽

10.1177/1420326x17729742 ◽

2017 ◽

Vol 28 (1) ◽

pp. 34-45 ◽

Cited By ~ 1

Author(s):

G. W. Zou ◽

H. Y. Hung ◽

W. K. Chow

Keyword(s):

Experimental Data ◽

Fire Safety ◽

Air Entrainment ◽

Pool Fire ◽

Flame Height ◽

Vertical Shaft ◽

Entrainment Velocity ◽

Fire Safety Design ◽

Fire Whirl ◽

Gap Width

An internal fire whirl can be generated by a pool fire burning in a vertical shaft with a single corner gap of appropriate width. In an internal fire whirl, the flame height is an important characteristic in terms of fire safety. In this paper, a correlation expression of flame height with the width of a single corner gap was studied using reported experimental data in a 9-m tall vertical shaft model. A pool of gasoline fuel was burnt inside the shaft model to study the characteristics of flame swirling. An internal fire whirl was generated for gap widths lying between 0.11 m and 0.66 m, when the pool fire was 0.46 m diameter. The flame height was between 2.5 m and 3.2 m. From the experimental observations on flame swirling for different gap widths, coupled with three assumptions on variation of air entrainment velocity with height, an expression relating the flame height and the corner gap width was derived for the internal fire whirl using a set of compiled experimental data. The correlation expression obtained would be useful for fire safety design in vertical shafts.

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