Abstract: To study the effectiveness of large transformer extinguishing system in State Grid sites, the large transformer fire extinguishing test platform has been built and 220 kV transformer fire model was employed to compare the fire extinguishment capability of compressed air foam extinguishing system and foam spray system. The test results showed that: under the same fire conditions, the compressed air foam extinguishing system of 6 L/(min·m2) foam application rate at 0.7 MPa can put out fire within 34 s. The foam spray system of 8 L/(min·m2) foam application rate at 0.7 MPa could put out fire in 39 s, only remaining high level oil pan slash fire. The tests showed that the fire extinguishment capability of compressed air foam extinguishing system was better than that of foam spray system. The experiment provided technical parameters and experimental basis for fire protection design of large transformer.

Key words: large transformer, transformer fire, compressed air foam extinguishing system, foam spray system, effectiveness of fire suppression