Experimental study on combustion characteristics of continuous oil spill fire on porous bed

As a traditional fossil fuel, petroleum fuel is prone to spill fires during storage, transportation, and use, which poses a significant threat to the secure utilization of energy. This research aims to investigate the effect of porous media on the combustion characteristics of spill fire. Quartz sand (diameter is 1.5 mm) is selected as a porous material, and continuous oil spill fire experiments under different oil discharge rates (25-100 mL & BULL;min(-1)) are carried out on both smooth substrate and porous bed. The spread process, burning rate, flame height and spread speed are measured and analyzed. The results show that no burning layer shrinkage occurs during the spread process. There is a significant increase in the stable burning length and in the time required to reach the quasi-steady burning phase. The burning rate of spill fire on a porous bed is negatively correlated with the thickness of the sand layer and positively correlated with the oil discharge rate, but it is still lower than the burning rate of pool fire under the same equivalent diameter. Transformer oil spill fire propagation speed is divided into three stages: acceleration-uniform-deceleration. When the oil discharge rate is 50 mL & BULL;min(-1), the uniform propagation speed of flame is 0.55, 0.11 and 0.03 cm & BULL;s(-1) respectively. Flame height is positively correlated with oil discharge rate and negatively correlated with sand thickness. Furthermore, a dimensionless coefficient, d*, is introduced to modify the flame height and burning rate models, and the correctness of the modified model is verified by experimental data. This study is informative for the safe use of liquid fuels.