Influence of active mitigation barriers with fans on dense gas dispersion

The situation in the global energy market has recently led to a sharp increase in the number of regasification terminals to import natural gas in liquefied form (LNG). Because of the hazard of these systems and the risk of fire and explosion due to possible accidental breakages, in recent years the technical community has been trying to define solutions for the mitigation of the consequences of major accidents. In previous works, methodologies for the design of containment wall of possible explosive cloud and curtains of vapor/air have been defined. The aim of this study is the suggestion of an active barrier and the definition of a methodology that allows to determine the airflow rate, generated by fans, required to dilute an LNG flammable cloud down to LFL. Results showed that with the proposed methodology the designed active barrier is able to stop the cloud at its location, minimizing the consequences of the release and improving the performance of a passive barrier. • CFD is used to model the dispersion after an accidental release of LNG. • CFD is used to analyze the performance of active mitigation barriers obtained with fans. • LNG is considered a particular and important case of heavy gases. • A simple methodology for the design of active barriers is proposed.