铀尾矿库滩面植被分布对尾矿砂大气迁移影响的数值模拟  

Simulation for the impact of vegetation distribution on the migration of the tailing sands on the uranium tailings impoundment beach

作　　者：张欣[1] 彭小勇[1] 黄帅[1] 

机构地区：[1]南华大学城市建设学院,湖南衡阳421001

出　　处：《安全与环境学报》2013年第6期269-273,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(11075072)

摘　　要：应用CFD数值方法和多孔介质模型研究了平地型铀尾矿库中坝体滩面植被分布对尾矿砂大气迁移的影响。对尾矿库滩面不同结构形式植被的防护效果进行对比分析,寻求一种较为有效的植被分布方式,以解决尾矿库运行期间干滩扬尘造成的严重辐射性污染问题。分析了在铀尾矿库滩面4种植被分布形式下10μm细尾矿砂大气扩散的质量浓度分布和沉降规律。结果表明:当尾矿库放置方向垂直于常年主导风向(来流方向)时,下风向覆盖1/4植被时其周围区域尾矿砂颗粒质量浓度最大,尾矿库下风向一定区域后质量浓度变为最小,其防护效果最好,上风向覆盖1/4植被时次之,上下风向均覆盖1/8植被时防护效果最差;尾矿库放置方向平行于来流方向时的抑尘效果较垂直放置的抑尘效果好。Via the CFD numerical method and porous media model, the paper intends to bring forward the results of its numerical simula tion to the influence of the vegetation distribution on the migration of the tailing sands, which come to pass on the beach of the dam in ura nium impoundment tailings. The contrastive analysis on the dustcon trolling effect of different vegetation distributions on the beach surface may contribute to disclosure of the facts that wellconserved vegetation helps to suppress the effect on reducing the sanddust pollution. Moreover, it has also proved that a more effective vegetation distribu tion is favorable for dust suppression during the operational period of uranium impoundment tailings, caused main]y by the windtaken small particles in the bare tailing sand form in the air on the dry beach surface in addition to the serious radioactive pollutants. Further analysis has made us clear that there were four different kinds of veg etation distributions that tend to reduce the impact of the migration of the small dust particles＇ migration with the radioactive pollutants in a size about 10 /lm. The simulation results we have gained also show that, when the uranium impoundment railings migrate in a perpendic ular direction to the perennial dominant direction （windward）, as compared with the other three cases, under the condition that there was only 1/4 of the vegetation coverage in the downwind area of the impoundment tailings, the largest particle concentrations tend to come about around the vegetation area, whereas the smallest concentration would come up around in a certain distance away from the tailing area in the downwind area. Therefore, the best dust suppression effect can be expected to come about in all such conditions. And, then, in the upwind area with 1/4 vegetation coverage would follow. However, the worst effect took place on the condition with 1/8 vegetation cover age, both in upwind and downwind directions. Thus, the dust sup pression effect in the railings impoundment areas pa

关 键 词：环境工程学 铀尾矿库 植被分布 数值模拟 抑尘 

分 类 号：TL752.2[核科学技术—辐射防护及环境保护]