Burning process and fire characteristics of transformer oil: A study focusing on the effects of oil type

The burning process and fire characteristics of typical transformer oils were investigated experimentally with a focus on the effects of transformer oil type. The experiments were conducted by using a cone calorimeter, and the conditions with five external radiative heat fluxes (ERHFs) were adopted. The results indicated that both the ERHF and oil type influenced the burning process and fire characteristics of transformer oil. The fire hazards of 10#, 25# and 45# transformer oils all increased with increasing ERHF. The flame became violent and spread to the outside of the fuel tray in the mid-late stage of burning duration when the ERHF was larger than 20 kW m(-2). The mass loss rate, heat release rate (HRR) and CO and smoke production rates of the 10# and 25# transformer oils were similar, and the fire hazard of the 45# transformer oil, as indicated by the above parameters, was larger than those of the 10# and 25# transformer oils. The correlations used to predict the ignition time and peak HRR of the 10#, 25# and 45# transformer oils under different ERHFs were presented based on correlation analysis of the ERHF and cone calorimeter test data.