Fire Dynamics and Evacuation Simulation of a Lithium Battery-Powered New Energy Sightseeing Vessel

This study investigates fire dynamics and passenger evacuation for a lithium-battery-powered sightseeing vessel using Pyrosim 2024 and Pathfinder 2019. Fire scenarios with varying ignition locations (lower battery compartment, first-deck cabin, second-deck cabin), heat release rates (4000 kW and 500 kW), and exit conditions were simulated to evaluate temperature, CO concentration, visibility, and smoke propagation. Evacuation simulations examined the effects of occupant load (100 vs. 185 persons), spatial distribution, and age composition on total evacuation time. Results demonstrate that ignition location governs fire development: lower-deck battery fires pose the highest risk, with smoke engulfing the entire vessel within 200 s and all compartments exceeding tenability limits within 180 s—55% faster than upper-deck fires. Reducing fire power from 4000 kW to 500 kW delays critical threshold attainment by only 22% (sensitivity coefficient = 0.032), confirming that fire location dominates over fire intensity in enclosed ship compartments. Exit blockage accelerates environmental deterioration in the fire-origin cabin by 56% but shows limited effect on remote compartments. Evacuation time increases by 56% when passenger load rises from 100 to 185, and uneven passenger distribution causes delays equivalent to adding 60–70 additional occupants. In contrast, age composition exerts only a marginal effect. The forward deck consistently remains the safest area across all scenarios. These quantitative findings provide prioritized engineering guidelines: lower-deck battery compartment fire protection, occupant density control, and uniform passenger distribution are the most critical factors for enhancing fire safety in battery-powered passenger vessels.