Modelling an integrated impact of fire, explosion and combustion products during transitional events caused by an accidental release of LNG

In a complex processing facility, there is likelihood of occurrence of cascading scenarios, i.e. hydrocarbon release, fire, explosion and dispersion of combustion products. The consequence of such scenarios, when combined, can be more severe than their individual impact. Hence, actual impact can be only representedby integration of above mentioned events. A novel methodology is proposed to model an evolving accident scenario during an incidental release of LNG in a complex processing facility. The methodology is applied to a case study considering transitional scenarios namely spill, pool formation and evaporation of LNG, dispersion of natural gas, and the consequent fire, explosion and dispersion of combustion products using Computational Fluid Dynamics (CFD). Probit functions are employed to analyze individual impacts and a ranking method is used to combine various impacts to identify risk during the transitional events.The results confirmed that in a large and complex facility, an LNG fire can transit to a vapor cloud explosion ifthe necessary conditions are met, i.e.the flammable range, ignition source with enough energy and congestion/confinement level. Therefore, the integrated consequences are more severe than those associated with the individual ones, and need to be properly assessed. This study would provide an insight for an effective analysis of potential consequences of an LNG spill in any LNG processing facility and it can be useful for the safety measured design of process facilities

Gas dispersion risk analysis of safety gap effect on the innovating FLNG vessel with a cylindrical platform

© 2016 Elsevier Ltd. While the effect of the safety gap on explosions is well known, little has been carried out to evaluate the effect of the safety gap on dispersion of gas releases, this paper evaluates the effect of safety gap on gas dispersion for a cylindrical Floating Liquefied Natural Gas (FLNG) vessel. The realistic ship-shaped and circular FLNG platforms are established and used for the detailed CFD based analysis; rather than the structural and hydrodynamics advantages of mobility, stability and cost efficiency etc., this study aims to investigate the safety of gas dispersion on the cylindrical FLNG and compare the safety gap effects on different configurations. A series of different safety gap configurations are evaluated for gas dispersion occurring in near field for the traditional FLNG while both near field and far field gas dispersion simulations are conducted on the cylindrical one. The overall results indicate that the safety gap is effective in reducing the gas cloud size in both FLNG configurations, however, when it comes to the gas dispersion in the far field against the leakage point, the safety gap increases the gas cloud size in the cylindrical FLNG vessel on the contrary