Simulation of Benzene Leakage and Dispersion in the Laboratory via Computational Fluid Dynamics

This study investigates the internal conditions of laboratory and effectiveness of ventilation system with evaporation of benzene from a hypothetical accident by using a computational fluid dynamic program. There are five inlets which moist air enter and exits through four vent hoods connecting with the exhaust fan was placed on the ceiling. The species model and the realizable k-e turbulence model with standard wall function are used to investigate the effects of turbulence. The benzene leakage source in laboratory was modelled as vapour phase with natural evaporation rate and the ventilation system was set up with different modes such as 1,000 m3/h, 2,000 m3/h, 3,000 m3/h, and 4,000 m3/h. The objective of this research is to investigate chemical leakage and dispersion in indoor environments and consider the performance of ventilation system of different exhaust fan modes and various layout designs (single-inlet or multi-inlets). Based on the analysis of air flow patterns and the distribution of pollutant concentrations, the performance of the ventilation system is evaluated and appropriate solutions are proposed to manage the problem. The results show that in both cases of opening all doors and opening only doors, the ventilation rate of 3,000 m3/h is considered to be the most effective in terms of pollutant removal because the benzene concentration meets the safety standard (< 10 ppm), namely 4.6 ppm in the multi-inlets and 2.8 ppm in the single-inlet.