Research on coverage optimization and verification of oil depot fire and gas system detectors based on Effigy software

To address monitoring blind zones in oil depot Fire & Gas System (FGS) detector layouts, this study proposes a performance-based optimization methodology compliant with ISA 84.00.07 standards. Targeting a refined oil depot, we constructed a 3D risk model using Effigy software integrated with DNV Safeti gas dispersion data to quantitatively evaluate detector coverage and optimize layout. Results demonstrate: Initial gas detector coverage was merely 57.4%. Through deployment of 5 additional gas detectors and 3 flame detectors, overall coverage increased to 95.8%, reducing residual risk to 4.3×10^-4/year. This methodology provides technical support for high-reliability FGS design.