Abstract: In order to solve the technical problem that UHV converter transformer fires are difficult to fight, a method for extinguishing the full liquid level oil spill fire through compressed air foam monitor system is proposed in this paper. 1∶1 full-size UHV converter transformer solid fire model is adopted. Unfavorable fire-extinguishing conditions such as high-temperature hot oil and full-liquid-surface oil spill fires are set, and the effectiveness of the compressed air foam monitor system in fighting full-liquid-surface oil spill fires is studied. The test shows that under the flow rate of 48 L/s foam solution, the fire is extinguished in 210 s, and the high temperature transformer oil is reduced to below 100 oC after supplying foam for 6 minutes. During the fire extinguishing, the left accident oil pool takes longer to extinguish the fire, attribute to higher temperature and longer pre-combustion time, whereas the compressed air foam monitor system can quickly cool down the temperature of the tank wall, prevent the oil spill from vaporizing, and effectively extinguish the oil spill fire.

Key words: compressed air foam, fire monitor, fire extinguishing system, UHV converter transformer, high-temperature oils, spill fire