Author(s)

YANLIN JIN, BEOM-SEON JANG

Abstract

Explosion risk analysis (ERA), one of the dedicated safety studies in offshore risk assessment, aims at evaluating the design accidental loads (DALs) for offshore topside structures and facilities. This study is an effort to propose a new type of flammable gas cloud frequency distribution appeared ERAs for offshore topside process. Flammable gas cloud distribution is a kind of intermediate result which is used for investigating a number of appropriate explosion scenarios by incorporating the results of frequency analysis, gas dispersion and ignition probability modelling. It is well known that the consequences of explosion accidents may vary strongly depending on variables such as the locations of ignition sources, gas cloud positions, sizes, and shapes, etc. This study is devoted to presenting an appropriate way to quantify the gas cloud position by using the results of dispersion simulations and reflect them into the proposed distribution to break through what were only addressed qualitatively by engineering judgement before. Using the proposed distribution, frequency of explosions is distributed over the gas cloud size and the position, and one can therefore expect a number of more realistic explosion scenarios which may improve the accuracy of DALs to a certain extent.

Keywords

explosion, risk, ERA, DAL, gas cloud distribution