Wind Tunnel Experiment And Numerical Simulation Of The Influence Of Smoke Tower And Smoke Exhaust On Close Environment

With wind tunnel tests and numerical simulation, this article mainly studied the effect of the flue gas discharge by natural draft cooling tower on nearby atmosphere environment. And based on it, the regularities of the impact, the different factors on the cooling tower downwind cavity area and the pollutant ground concentration, are discussed in-depth. Also, these methods, as to predict the effect of the flue gas discharge by natural draft cooling tower on nearby atmosphere environment, are analyzed about their advantages and disadvantages. The conclusion has certain reference values to predict its effect.Firstly, the environmental wind tunnel is used to test the simulation on the cooling tower smoke exhaust. The general boundary of downwind cavity area is distinguished by measuring the distribution of turbulence intensity,as no smoke is discharged. And the impact by wind speed on transmission and diffusion of flue gas pollutants is estimated by the measuring of the different ground NO2 concentration distribution with different wind speed.Secondly, to numerical simulate the cooling tower smoke emissions,the computed fluid dynamical software( Fluent software) is used. Give priority to with numerical simulation, aiming at cooling tower edge downwind 2 kilometers in close range, cavity area's range is calculated by two-dimensional model, under different environmental wind speed and different cooling tower exhaust velocity. Then, with these results, their effects on boundary of cavity area are analyzed. And with 3D model, the cavity area and the ground concentration of pollutants are exactly calculated again, so as to estimate how cavity area and environmental wind affect the ground concentration of pollutants. Combined with two-dimensional model before,the regularity of cavity area affecting the pollutants' downwash is clear.Later, with German Austal2000 standard model, the pollutant concentration close to the ground is simulated and calculated again. Through this method, the rule of the flu gas pollutant ground concentration changed by environmental wind speed is analyzed, which is limited within 2000m at close range. It shows that the German Austal2000 standard model is unreliable, when this method is used to predict the effect of the flue gas discharge by natural draft cooling tower on nearby atmosphere environment in our country.Finally, physical wind tunnel experiments, numerical wind tunnel simulation, as well as Germany Austal2000 model calculation are synthesized. These predictions about the effect of the flue gas on nearby atmosphere environment with three methods are compared and the differences are analyzed. Then summarize these methods'strengths and weaknesses for predicting the environmental impact of close range by cooling tower flue gas exhaust, as well as draw the conclusion.