Experimental Investigation of the Spread and Burning Behaviors of Diesel Spill Fires on a Water Surface

Large quantities of water are often used to extinguish fires when accidental fuel leakage occurs during storage and transportation. This may lead to spill fires on water. Boilover and splash of heavy oil spill fires in particular can pose a serious thermal threat to surrounding facilities and personnel. In this work, a series of diesel spill fire experiments were conducted on the surface of water. The results showed that, for the non-ignition cases, the fuel spread velocity was fast at first, then maintained a long period of steady spread, which can be successfully predicted by a developed spread model. During the ignition process, the burning of diesel fuel is divided into four phases. Following a brief quasi-steady burning phase, we observed an expansion of the burning area during the intermittent boilover phase, which was primarily driven by boilover. During the quasi-steady burning phase, the burning rate was lower than that of pool fires, which is attributed to the heat loss between the diesel and water layers. This heat loss also results in a lower flame height than the pool fire, and a dimensionless equation was proposed to eliminate discrepancies. During the intermittent boilover phase, the increase in the burning area was used to characterize the boilover intensity, which was found to be negatively correlated with the number of boilovers. Furthermore, the emergence of the boilover also caused flame radiation to rise rapidly; it was about 19% to 30% higher than that in the quasi-steady burning phase.