Improved Gaussian Plume Model And Its Application In Hazardous Chemical Spill Simulation

In recent years, China’s chemical industry have faced more severe test than the otherprofessions because of the double pressure of environmental protection and a new roundadjustment of industrial structure. Chemical industrial park as a new development model ofchemical industry has developed rapidly in our country. The chemical industrial park’s quickdevelopment has brought out many security and environment problem. Moreover production inthe chemical industry was more riskier compared to other professions, and the toxic gas leakageaccidents were always sudden and uncontrollability. The characteristics of hazardous chemicaland chemical accidents was introduced, while the statistics of chemical accidents were presented.The diffusion model can be used to describe the diffusion behavior of the gas leakage inatmosphere, the theory of leakage source and gas diffusion model were briefly introduced. Forvarious kinds of models, several kinds of gas diffusion model which were matured developed orresearch focus were chose for presentation in this paper, such as Sutton model, Gaussian model,Pasquill-Gifford model and some representative heavy gas diffusion model. By comparison, Gaussiandiffusion model with simple mathematics expressions, intuitionistic senses, direct physicalsignificance and high applicability was studied in this paper, especially the Gaussian plumemodel used for describing the pollutant concentration from continuous steady state emissionsource.Gaussian plume model with some foundation hypothesis conditions should be modified inpractice for higher accuracy and less errors in condition of dealing with complex problem.Combined with the real situation of Qingyuan overseas Chinese industry park, the model wasmodified in some aspects, such as source strength, wind velocity and effective height, andachieved the objective of higher accurater analysis.In this paper the method of integrating GIS with diffusion model was used to simulate thethree-dimensional diffusion process and predict the impact scope of the accident. WithVisualC++6.0as the development platform, the integration of Gaussian plume model and GISwas achieved. The system for the three-dimensional simulation and visualization of incidentconsequence, which could well predict the emission concentration distribution and make thecoverage, extent of injury and development tendency open-and-shut, was exploited successfully. The system was applied for an example with controlled condition to analyze theconcentration distribution after the incident took place. The system is not just convenient fordrawing up critical situation pre-arranged planning, but could offer timely assistant decision foremergency command.