Assessment on the Overflow Risk of the Large-Scale Oil-filled Electric Equipment under the Joint Action of Multiple Fire Extinguishing Systems

The assessment on the overflow risk of the large-scale oil-filled electric equipment under the joint action of multiple fire protection systems were explored experimental in the present study. Eight combine forms of the water spray system, the fire water monitor, the fire-extinguishing water tanker, the foam spray system, the low-expansion foam monitor and the fire-extinguishing foam tanker were investigated. The results show that the liquid height increased faster when the AFFF foam was adopted, and the ratio between the flow rates of the water and the AFFF foam concentrate was a key parameter to the overflow risk. According to the experimental results, all the eight conditions had no overflow risk. However, the following two conditions should be considered: the liquid height was just below the level of pebble bed when the flow rates of water and 3% AFFF foam concentrate were 2.11 and 0.043 L/s, respectively. When the ratio between the flow rats of water and AFFF foam concentrate reached to 32:1, the liquid height increased continually with time.