A study on effective mitigation system for accidental toxic gas releases

In this study, ANSYS FLUENT, a computational fluid dynamics (CFD) program, is used to assess the efficiency of installing a physical barrier as a mitigation action against HF and chlorine leaks from industrial facilities. In a typical industrial facility, a barrier is usually set to separate the workplace from the outside environment, but it is not sufficient to prevent the release of hazardous substances outside the facility. Therefore, we analyzed the efficiency of various heights of physical barriers (3 m, 6 m, and 9 m) for mitigating toxic gas releases using simulation. The results of this study were compared to the experimental data obtained by Goldfish in 1986 to verify the results of HF. These results were also compared to the data obtained by Jack Rabbit in 2010 to verify the results of chlorine. The mitigation effectiveness factors of HF and chlorine were derived, and the results indicated that the increase in the barrier height decreases the concentrations of these gases in the surrounding area. In addition, it was proven that the proposed mitigation system can reduce the possibility of an offsite exposure to toxic gases in case of a release and enhance the effectiveness of the emergency plans.