论文和技术资料

Almost all industrial processes produce exhaust and use chemicals potentially harmful to humans. This is even more applicable for chemical industries whose primary raw materials and products may be detrimental to people’s health. As a result, people working or living nearby chemical industrial clusters remain in a heightened state of risk for prolong exposure and accidental catastrophic chemical leakage events. Sudden accidental release of chemicals needs to be considered for industrial design and planning. Such events pose serious risk to the workers and the community living close to the industrial areas. Exposure to toxic chemicals can cause severe health outcomes and, on some cases, even death. It can also cause damage to surrounding wildlife, vegetation, natural water sources, the soil and the local ecosystem. The stakes are quite high when it comes to planning and response to such emergency scenarios. Mathematical simulation can be a very effective tool to make plans for accidental situations. Modeling sudden catastrophic chemical releases can provide insight into dispersion trends depending on various chemical properties, ambient conditions and terrain characteristics. Proper precautions and emergency responses can be effectively planned and implemented based on the comprehensive understanding gained from such simulations.

A finite element model of an industrial chemical storage unit releasing its content on the surrounding environment was developed. It was developed using COMSOL Multiphysics. The developed models were executed on both workstation and supercomputer depending on the domain size and the simulation time. Compared to the entire geometry of the model, small element size was used to obtain a high-resolution model which provided detailed and accurate simulation of a real world catastrophic chemical release. The diffusion and convection of the released chemical are the prevailing driving mechanism of transport. The dispersion trend was estimated by using Fick’s 2nd law of diffusion integrated with convection by velocity field of ambient air. A turbulent flow model was employed to simulate the wind velocity field, with altitudinal wind speed variation systematically incorporated into the analysis. Physical, thermodynamic and transport properties of the chemical were used to estimate the phase and leakage flow properties. The effects of varying terrain conditions on the dispersion of the chemical were observed, such as plain terrain and terrain with varying number of obstacles. Velocity field for different wind speeds have been calculated by using compressible form of the Navier-Stokes and continuity equations. Varying wind speeds’ effect on the dispersion trends were observed over time. The influence of velocity field on the local concentration buildup of the released species was interpreted based on the fluid mechanics principles and phenomena.