Numerical Simulation Study on the Dynamic Diffusion Characteristics of Ammonia Leakage in Ship Engine Room

This study established a numerical model for ammonia leakage and diffusion in confined ship engine room spaces and validated its effectiveness through existing experiments. The research revealed the evolution patterns of ammonia cloud dispersion under various working conditions. Multi-parameter coupling analysis demonstrated that the combined effect of leakage source location and obstacle distribution alters the spatial configuration of gas clouds. When leakage jets directly impact obstacles, the resulting vortex structures maximize the coverage area of high-concentration ammonia near the ground. Ventilation system efficiency shows a significant negative correlation with hazardous zone volume. The hazardous zone volume was reduced by 50% when employing a bottom dual-side air intake combined with a top symmetric exhaust scheme, compared to the bottom single-side intake with an opposite-side top exhaust configuration. By enhancing the synergistic effect between longitudinal convection and top suction, harmful gas accumulation in lower spaces was effectively controlled. These findings not only provide a theoretical basis for ventilation system design in ammonia-fueled ships but also offer practical applications for risk prevention and control of maritime ammonia leakage.