Experimental and numerical study of the fire behavior of a tank with oil leaking and burning

Leaking-burning coupling fires caused by oil leakage from tanks cause significant damage to occupants and the equipment. A series of experiments was conducted to investigate the fire behavior of a tank with oil leaking and burning. The tank released n-heptane into the tray below, forming a fire that heated the tank. The tray size and leak diameter varied. Spill fires, steady pool fires, boiling pool fires, and jet fires were observed. The results show that within a specific leak diameter range (2.5–3.5 mm), the maximum pressure increased with decreasing leak diameter. The fuel vapor spread along the bottom of the tank, causing the expansion of the flame. Consequently, the pool fire size was larger than the actual tray size, thereby making the maximum pressure and thermal radiation almost independent of tray size. When the leaking oil began to boil and burn, the pressure increased rapidly and the emitted radiative heat flux was the largest; therefore, fire posed the most serious threat. A computational fluid dynamics (CFD) modeling approach was employed to predict the time when the temperature of the leaking oil reached its boiling point. The predicted results were validated against the experimental ones, which provided useful support for emergency response plans.