Characteristics And Prevention And Control Measures Of Boilover Fire On Small-scale Oil Tank

Boilover fire is the most dangerous type in several kinds of oil tank fires. When boilover occurs, the burning oil droplets are boilovered and splashed out of the tank. The duops and the strong radition of flame pose a seriously threat to the rescue people, facilites around and the environment. The theory of boilover has not been understood due to its complexity. Hence, conducting research on boilover fire mutation process and fire charcaterics, analyzing the oil tnak fire damage and discussing the prevention and control measures have a significant meaning to understand the boilover theory, along with the fire rescue.The main contents and conclusions are listed below:(1) The experiemental device of studying the small-scale oil tank boilover characteristics was set up. Experimental skeme with tanks in different diameters and heights was designed in different fill rate and oil-water ratio. The oil properties were tested. Both the experimental parameters and procedures were established.(2) The boilover process of oil tank was experimentally studied firstly. It was indicated that three stages were divided in the entire process:quisi-steady combustion stage, boilover premonitory stage and boilover stage. The flame characteristics differ in different stage listed above.(3) Visualization experiments of oil tank boilover were conducted. The results indicate that the formation of boilover results from the reciprocity of bubbles and oil vacuoles generated by absorbing energy released from combustion reaction.(4) The cover radius and splash radius were defined respectively to evaluate the effect of boilover to the ambient. The results show that, the cover radius is about 1.5D-2.5D for tank with diameter of 100mm and 1.5D-2D for tank with diameter of 200mm.(5) A heat transfer model of tank boilover was established. The boilover starting time was sovled based on the model. The comparison of model results and experimental results indicates that they agree well.(6) The calculating method of boilover starting time was discussed. It is found that the boilover starting time is linearly proportional to the parameter Ho/D0.5. The correlation between boilover starting time and Ho/D0’5 was given.(7) Both the positive and negative measures of boilover fire were discussed. The results show that the aluminum silicate wool can suppress the occurrence of the boilover fire efficiently, being as a positive measure. However, the thickness of alumimum silicate wool and the time when aluminum silicate wool was put have a significant effect on suppression. Two negative measures of using boilover starting time and boilover radius as parameters were raised.