Full-Scale Fire Suppression Experiment of a Water-Based Extinguishing System for Electric Vehicle Fire Response

The distribution of electric vehicles (EVs) in South Korea continues to expand owing to government policies aimed at reducing greenhouse-gas emissions and fostering future industries. As of July 2024, 621,000 EVs were registered, with 1.32 fire incidents reported per 10,000 vehicles in 2023. A two-stage experiment was conducted to verify the fire suppression and control performance of the sprinkler and undercarriage sprinkling systems, which are the basic fire safety facilities for responding to EV fires. The experiment also targeted EVs with different battery types and included a lower two-line sprinkling system, which was not used in previous experiments. In the first stage, a domestic EV equipped with pouch-type batteries was tested using the upper sprinkler and lower two-line sprinkling system. In the second stage, a foreign EV equipped with cylindrical batteries was tested using the upper sprinkler and lower one-line sprinkling system. The results showed that in the first and second stages, the battery loss rates were approximately 30%, and 100%, respectively. Although various experimental conditions affected the thermal runaway duration, loss rate, and fire spread to adjacent vehicles, cooling the battery pack using both the upper and lower water-based extinguishing systems delayed thermal runaway and effectively prevented the spread of fire. Notably, the lower sprinkling system showed differences in thermal runaway duration and fire-suppression performance depending on the battery cell type.