The transformer oil within the piping of ultra-high voltage converter transformers is prone to evaporation, forming a flammable oil–gas mixture. In the presence of an ignition source, an explosion of transformer oil can cause severe damage to the power equipment. Currently, experimental studies on the dynamic evolution of transformer oil explosions are lacking. The effects of transformer oil volume and distance on the overpressure evolution and fireball behavior of transformer oil explosions are investigated, as well as the blast resistance performance of the clamped steel plate. Experimental results show that as the distance between the pressure measurement point and the explosion center increases, the peak overpressure gradually decreases. When the transformer oil volume increases from 8 to 16 l, the fireball behavior induced by the explosive charge remains similar, but the peak overpressure decreases. The explosion of 16 l of transformer oil produces the largest fireball radius and maximum area among all tested oil volumes. Due to the limitations of the explosive charge and oil volume, the peak overpressure reached ∼43.67 kPa, which did not cause noticeable damage to the clamped steel plate.
Huang et al. (2026) studied this question.