Safety and Structural Integrity Assessment of the Battery Room in a 40-Passenger, 350 kW Hydrogen-Propelled Vessel

This study investigates the gas safety hazards and blast-induced structural response associated with lithium-ion battery thermal runaway in a 40-passenger, 350 kW hydrogen-propelled vessel. Thermal-runaway experiments identified methane, carbon monoxide, and BTEXS-series volatile organic compounds in the released gases. Methane and carbon monoxide were selected as representative combustible components for explosion-pressure tests, which produced a maximum explosion pressure of 2.739 MPa at a mixed-gas concentration of 29.76 vol.%. This pressure was converted into an equivalent TNT mass and applied as a blast load to a nonlinear finite-element model of the battery-room transverse bulkhead, with the structural response evaluated as a function of battery-rack-to-bulkhead separation distance. For the 2000 mm high bulkhead, the allowable displacement criterion of H/40, corresponding to 50 mm, was exceeded at separation distances of 1.1 m or less but satisfied at 1.2 m or greater. These results demonstrate that thermal-runaway off-gas constitutes a vessel-level gas and explosion hazard with direct implications for structural safety, providing a quantitative basis for battery-rack separation distance and informing the integration of gas detection, ventilation, pressure relief, and bulkhead reinforcement in hydrogen-propelled vessel design.