Experimental Study on Spreading and Burning Characteristics of Continuous Spill Fire under Low Pressure

To investigate the influence of low ambient pressure on spill fire, the methanol spill fire experiments on fireproof glass with discharge rates ranging from 60 to 180 mL/min were conducted in a low-pressure chamber. The spread radius, burning rate, and heat transfer process between liquid layer and glass of spill fire were analyzed in-depth under low ambient pressure of 60 kPa and atmospheric pressure of 101 kPa. The results showed the entire spread process of spill fire and found that the spreading radius under atmospheric pressure was slightly smaller than that under low-pressure environment. The burning rate of spill fire under atmospheric pressure is lower than low pressure which the relation between pressure and burning rate can be expressed as m proportional to p(0.3)(2) . With respect to the heat transfer process, the heat loss including radiation penetration and heat convection under 60 kPa was lower than under 101 kPa, and the heat convection loss was dominant under two pressures. Finally, a semi-theoretical model was developed to estimate the burning rate in the quasi-steady stage by considering the spreading radius and heat transfer process. The model was validated with the experimental data and showed reasonable accuracy.