Jet Flame Risk Analysis for Safe Response to Hydrogen Vehicle Accidents

With an increase in the use of eco-friendly vehicles such as hybrid, electric, and hydrogen vehicles in response to the global climate crisis, accidents related to these vehicles have also increased. Numerical analysis was performed to optimize the safety of first responders responding to hydrogen vehicle accidents wherein hydrogen jet flames occur. The influence range of the jet flame generated through a 1.8-mm-diameter nozzle was analyzed based on five discharge angles (90, 75, 60, 45, and 30◦ ) between the road surface and the downward vertical. As the discharge angle decreases toward the road surface, the risk area that could cause damage moves from the center of the vehicle to the rear; at a discharge angle of 90◦ , the range above 9.5 kW/m2 was 1.59 m and 4.09 m to the front and rear of the vehicle, respectively. However, at a discharge angle of 30◦ , it was not generated at the front but was 10.39 m to the rear. In response to a hydrogen vehicle accident, first responders should perform rescue activities approaching from a diagonal direction to the vehicle front to minimize injury risk. This study can be used in future hydrogen vehicle design to develop the response strategy of the first responders.