Investigation of temperature distribution and heat transportation involving flame spread over liquid fuel in a tube

Flame spread over liquid fuel possibly occurs in a long and narrow confined space, i.e., tunnel, pipeline or corridor. The spread of liquid fire in a tube belongs to the ventilation-controlled combustion. The 100 cm-long cylindrical quartz glass tube was built to examine flame spreading behavior on butanol surface in the tube. The inner diameters of the tube were 10 and 20 cm, respectively. The sealing ratio and sealing end position were controlled by the height and position of glass sheets at both ends. Three blocking methods were conducted: ignition-end blocking, non-ignition-end blocking and two-ends blocking. The effects of sealing ratio and sealing end position on flame spreading characteristics such as gas-liquid temperature distribution, oxygen concentration, preheating time and heat transportation of surface flow were revealed. The flame separation behavior was observed due to the insufficient oxygen supply. The non-ignition end blocking could effectively reduce the surface flow velocity and restrain the flame spread. The gas- and liquid-phase transfer involving surface flow of flame spread were revealed. For ignition-end blocking at D = 200 mm, when the blocking ratio increases from 10 % to 40 %, the radiant heat flow from front flame to surface flow area decreases by 17.6 %. © 2024 Elsevier Masson SAS