Evaluation of Hydrocarbon Gas Dispersion and Explosion in a Gas Processing Plant

Gas leakage is one of hazard sources in a gas processing plant, where the released gas may form vapor cloud, which is dispersed or accumulated. At certain concentration, the vapor cloud may induce fire and explosion, which could harm people, equipment and environment. The effects of the incidents can be estimated to determine the consequences and to improve the plant design. Due to several complexities including congestion of plant equipment, 3D CFD model was developed to represent real configuration. In this study, the as-built 3D plant geometry and FLACS software were utilized to run the CFD model simulation to evaluate the quantity and placement of the existing gas detectors. The recommendation given according to evaluation results was to install two additional gas detectors. Thereby, in the case of gas leak, the gas detection system may alarm personnel and preventive action may be taken into consideration. The effects of explosion result from the selected scenario were predicted to not be able to cause steel frame distortion or eardrum rupture. These demonstrated that the evaluation of release consequence using 3D CFD model gave more advantage than 2D method by representing accurately physical characteristic of gas dispersion and explosion, which could eventually improve the plant safety strategy.