In this study

an ammonia refrigeration room was selected as a typical scenario. Computational fluid dynamics (CFD) was applied to study the rules of the ammonia-leakage diffusion. The ammonia-leakage diffusion in a refrigeration room with up-down ventilation and without ventilation was numerically simulated using the Fluent CFD software package. The ammonia concentrations in the longitudinal profile and the cross-section of the refrigeration room were analyzed at different times after the ammonia leakage. The numerical simulation results show that the ammonia concentration increases with height in the refrigeration room

and a lower fresh-air inlet can quickly decrease the ammonia concentration. Based on the above results

it is proposed that an ammonia-gas alarm should be installed near the ceiling to detect the leakage

and an emergency exhaust inlet should be installed near the floor to decrease the ammonia concentration.