滨海核电厂址污染物扩散数值风洞模拟研究

Numerical wind tunnel simulation of pollutant diffusion in coastal nuclear power plant

为评估核电厂对周围环境的影响,集成CFD-数值风洞软件,采用Autocad进行前处理建模,采用Paraview软件进行后处理分析,以研究污染物在大气中的迁移扩散过程。利用2003年于俄克拉荷马州俄克拉荷马市进行的城市联合实地研究(IOP9)的观测数据对该数值风洞软件进行评估,比较了数值风洞与IOP9现场试验污染物释放点下风向轴线污染物体积分数和风场结果。比对结果显示,风场各性能统计指标F_(AC5)=F_(AC2)=1,F_(B)=-0.23,M_(G)=0.75,E_(NMS)=0.07,S_(AA)=11.9;污染物体积分数统计指标F_(AC5)=1,模拟结果与观测数据较吻合。以某滨海核电厂为对象,研究核电厂污染物在大气中扩散对周围环境的影响。数值模拟结果显示,垂直于来流风向污染物体积分数总体呈高斯分布,受地形影响在山脊等位置处体积分数会陡然下降。将数值模拟的体积分数和风洞试验结果进行比较,结果显示在各垂直剖面监测点的吻合因子为10,各水平剖面监测点的吻合因子为3.5。数值风洞模拟结果有一定的参考价值,与现场试验和风洞试验结合可为核电厂污染物扩散模拟研究提供便利。

To assess the impact of nuclear power plants on the surrounding environment,a CFD numerical wind tunnel software is integrated,AutoCAD is used for pre⁃processing modeling,and Paraview software is used for post⁃processing analysis to study the migration and diffusion of pollutants in the atmosphere.The numerical wind tunnel software was evaluated using the IOP9 observation data from the 2003 joint field study in Oklahoma City.The results of the numerical wind tunnel and the IOP9 field experiment on the volume fraction of the downwind axis at the pollutant release source point and the wind field at the monitoring point were compared.The wind field comparison results show that the performance statistical index values were F_(AC5)=F_(AC2)=1,F_(B)=-0.23,M_(G)=0.75,E_(NMS)=0.07,and S_(AA)=11.9;The volume fraction comparison results show that F_(AC5)=1.These statistical indicators are close to perfect values,which shows that the simulation results are in good agreement with the observed data.Taking a coastal nuclear power plant site as an object,the impact of pollutant diffusion in the atmosphere of nuclear power plants on the surrounding environment is studied.The results of numerical simulation show that the pollutant volume fraction perpendicular to the incoming wind direction is generally Gaussian distribution,and the volume fraction will drop sharply at the ridge and other locations affected by the terrain.Finally,the volume fraction of numerical simulation was compared with the results of wind tunnel experiments.The results show that the coincidence factor of comparison results at each vertical profile monitoring point was 10,and the coincidence factor of comparison results at each horizontal profile monitoring point was 3.5.The numerical simulation results are in good agreement with the wind tunnel test results.The numerical wind tunnel simulation results have a certain reference value and can be a convenient tool for pollutant diffusion simulation research in nuclear power plants when combined with field experiments and wind tunnel experiments.