Abstract: The fire suppression effectiveness of compressed air foam for bushing turret spill fire of transformer was studied through reduced - scale fire extinguishing experiments. The suitable fire extinguishing application method and application parameters were analyzed and proposed. The results showed that compressed air foam could effectively extinguish the bushing turret spill fire of transformer, and had a good ability of fire extinguishing and antireigniting.Under the condition that the foam solution supply intensity was 11.4 L/(min · m 2 ), the fire extinguishing time is 3.9 min. By supplying foam for 10 min, the transformer oil temperature could be reduced to below the ignition point, and re - ignition would not occur.Increasing the supply strength of foam solution can increase the speed of fire extinguishing and cooling. In actual engineering, it’s recommended to use a compressed air foam sprinkler system and a highly stable compressed air foam. The compressed air foam release device and the pipe network should adopt anti - explosion measures.

Key words: oil - immersed transformer, bushing turret, spill fire; compressed air foam, sprinkler fire extinguishing system