Experimental Study on Transformer Oil Pan Fire Suppression by ABC Fire Extinguisher Powder

An oil pan fire experiment was carried out to investigate the fire extinguishing efficiencies in controlling transformer oil fires for four types of ABC fire extinguisher powder. The experiment was performed according to GB 4066-2017. Mineral transformer oil #25 was used as the fuel and was heated to 80 °C in advance to account for the working temperature. Two types of sprayers, i.e., A tapered holed powder sprayer (THPS) and a cylindrical holed powder sprayer (CHPS) were installed in the experiment to study the effect of different powder sprayers. The fire extinguishing time, fire temperature and pressure varied with the powder spraying time and were recorded. It is found that both the super fine powder and 75% ammonium phosphate powder can suppress transformer oil fires effectively. The extinguishing efficiency of the latter depends on the spraying time, and the fire cannot be extinguished if the spraying time is too short. A gas leakage model can describe the pressure varying with powder spraying time.