Experimental study on the characteristics of natural ester oil pool fire in transformer room

In order to assess the fire hazard of two new transformers natural ester insulating and cooling oils, an experiment was conducted to examine the combustion characteristics of pool fires using rapeseed oil and soybean oil in transformer room. The results show that, compared with rapeseed oil, soybean oil is more likely to ignite under the same conditions. The vigorous combustion stage of a soybean oil pool fire lasts 30% longer than that of rapeseed oil. Additionally, the flame height and flame area of a soybean oil pool fire are larger, resulting in a more intense burning. The average temperature at the fire plume centerline of the soybean oil pool fire was approximately 50 °C higher than that of the rapeseed oil fire plume. The maximum thermal radiation intensity of the soybean oil pool fire was 14.7 kW/m² , which was similar to the rapeseed oil pool fire's intensity of 15.3 kW/m² . However, the duration of the thermal radiation phase with high intensity of the soybean oil pool fire was 27.3% longer than that of the rapeseed oil pool fire. Overall, the fire hazard of indoor combustion is greater for transformer soybean oil than for transformer rapeseed oil.