Experimental and numerical study of ammonia leakage and dispersion in a food factory

With the widespread use of ammonia in the industrial fields, more and more accidents are caused by ammonia leakage and dispersion. To study the dispersion law of ammonia in a food factory, small scale wind tunnel experiments were designed. Different initial conditions such as release flow rate, wind speed, release height and the heights of concentration sensors were considered. Ammonia concentration was measured near release source, obstacles and far from release source, respectively. The law of ammonia dispersion is determined by its physical properties, release source conditions and atmospheric environment. Ammonia concentrated in the axial direction and showed an upward movement near the source as ammonia's density is lower than the air. We obtained the law of ammonia dispersion in a food factory through experiments indicating that the concentration of each measuring point is proportional to the flow rate. With the increase of wind speed, the concentration of ammonia at different points first increased and then decreased. The results showed that the effect of ammonia dispersion was more obvious under the influence of the wind field. The maximum concentration can be reached under the wind speed range of 0.8-1.2  m/s. Changing the height of source and measuring point will make a great difference in the concentration of the measuring point. In the simulation work, RNG k-ε model represents better agreement with the experimental data. Ammonia movement has a strong concentration gradient and the horizontal wind field streamlined ammonia movement.