Experimental And Simulated Tracer Gas Leak Weight Plateaus City Proliferation

The development of industry not only brought huge economic benefits, but also brought great disaster to human beings and the environment. Now, the research of dense gas dispersion has becomes more and more important. Many researches and great attention has been paid to it. But, the wind tunnel experiment and simulation of dense gas leakage are not too much in plateau mountainous city at complex terrain. Because of the special terrain and meteorological conditions, the dense gas dispersion has special pattern. Therefore, the gas dispersion experiment and simulation to the concentration is necessary, and it will brings important significance to environment protection.In this paper, Gejiu, a mountainous city in the plateau, was researched based on a model of downtown and suburb area with a proportion of1:1000.Onsite data of wind profile was used to regulate the wind profile of wind tunnel, and to identify the characteristics of wind profile in Gejiu city. Velocity distributor, rough components and wind poles situated in the wind tunnel can be regulated to simulate the wind field mentioned above. The exponent of wind profile is0.59in neutral conditions. Determination spots were located to identify the variation of wind velocity in different terrain. Experiment shows that due to the complex terrain and crowded buildings in Gejiu, the wind velocity at the same height and the exponent of wind profile at the different site were different. Characteristic of wind of the central axis was used to evaluate the influence of mountain-crossing wind and terrain lock on the wind field.The rapid analysis method of CFC12with gas chromatograph is developed to determine the concentration of dense gas. By CFC12as the tracer material and the experiment shows that the result of peak height is better than that of the peak area. Different test points are selected and in the leeward (That is different underlying surface), besides, tacking samples and analysis the samples in these points. The result shows that there is a dangerous wind speed no matter how the underlying surface is. The concentration of dense gas reaches the maximum in the dangerous wind speed. The analysis result shows that the viscous coefficient also reaches the maximum as long as the wind speed reaches the dangerous wind speed. The value of dangerous wind speed calculated by fitting of polynomial is close to the experimental result.In this paper, AERMOD is adopted to simulate the dense gas concentration. At the same time, making the pretreatment module of terrain by meshing the topographic map and extracting the three-dimensional data of the test points, in combination with the meteorological preprocessor module to analysis the effect of different wind speed and different terrain conditions to the dense gas concentration. The result shows that the predicted results are close to the results of experiment.