Abstract:

The fire characteristics and fire hazard of typical transformer oils were measured by a cone calorimeter and cone calorimeter-Fourier transform infrared spectrometer under three different external radiative heat fluxes. The difference of combustion process and fire hazard of KI25X and KI50X transformer oils with different freezing point were studied. The results show that both the external radiative heat fluxes and the type of transformer oils affect the fire characteristics and fire hazard. With the increase of the external heating radiation flux, the ignition time of the two transformer oils were shortened, and the HRR, smoke generation rate and the peak concentration of the main toxic component CO in the flue gas increased accordingly.When the external radiative heat flux was increased to 35 kW/m², compared with KI25X, the fire spread speed of KI50X transformer oil was faster and its toxic gas concentration released was higher. So its thermal and smoke risk was higher than KI25X at this time.

Key words: transformer oil, cone calorimeter, fire characteristics, smoke hazard