This paper focuses on quantifying experimentally the evolution of conduction, convection and radiation heat feedback mechanisms and corresponding mass burning rates of ethanol pool fires (8, 10, 12, and 15 cm diameter) under external heat fluxes ranging from 0 to 4.0 kW/m2. The results show that the conduction heat feedback fraction is nearly independent of external heat flux, but decreases with pool diameter. Meanwhile, the contribution fractions of convection and radiation heat feedback mechanisms display a competitive relationship where the radiation heat feedback fraction increases with external heat flux while the convection heat feedback fraction changes in the opposite direction. The transitional external heat fluxes of the control regime are 3.3, 3.3, 2.8, and 1.3 kW/m2 for 8, 10, 12, and 15 cm pool fires, respectively. The increment of the corresponding mass burning rate gradually declines in the convection-controlled regime, while is nearly constant in the radiation-controlled regime. The flame heat transfer blockage fraction b is introduced to express the variation of mass burning rate in the radiationcontrolled regime based on a simple linear correlation. The heat blockage effect appears to be more significant for larger pool diameters given that the values of b are 0.008, 0.021, 0.056, and 0.128 for incremental pool diameters. Calculated mass burning rates based on the stagnant layer theory are in good agreement with the measured ones.
International Seminar on Fire and Explosion Hazards (9; 2019; Saint Petersburg, Russia). Proceedings of the Ninth International Seminar on Fire and Explosion Hazards [Электронный ресурс]. Vol. 1: 21-26 April 2019, Saint Petersburg, Russia / Peter the Great St. Petersburg Polytechnic University, Autonomous Non-Profit Organization "Fire and Explosion Safety", Gefest Holding Ltd ; [edited by A. Snegirev [et al.]. — Электрон. текстовые дан. (1 файл : 118 Мб). — Saint Petersburg, 2019. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/k19-45.pdf>. — <URL:http://doi.org/10.18720/SPBPU/2/k19-45>.
Access count: 186
Last 30 days: 6
Detailed usage statistics