Evaluation of the ventilation safety requirements for the fuel gas supply system room of a gas-fueled vessel: Simulated leaks of methane and propane

This study conducted the ventilation and gas dispersion analysis using fire dynamics simulator (FDS) for fuel gas supply system (FGSS) room of a 50000 dead weight tonnage (DWT) gas-fueled vessel sailing at a constant velocity, under the assumption that methane and propane gases leak in the fuel preparation room containing the FGSS. To assess the transient flammable extents for representative risk scenarios, four gaseous leak scenarios with the same mass flux were selected as follows: Propane at-30 degrees C and at 20 degrees C, and methane at-150 degrees C and at 20 degrees C. The same ventilation capacity was applied in each of these scenarios, with different inlet/outlet configurations. As a result, all cases satisfied the international code requirements for the hazardous areas of ventilation inlet/outlet and the gas detector locations. However, only the ventilation capacity requirement was insufficient to ensure optimum ventilation performance of the FGSS room. Therefore, a safety design procedure considering ventilation efficiency was required to determine the most appropriate number and location of ventilation inlets/outlets in the FGSS room beyond the international code.