核反应堆用除雾器过滤效率的数学模型

Mathematics Model of Filtration Efficiency of Moisture Separator for Nuclear Reactors

通过数值模拟方法计算了除雾器对于5～10μm水滴的过滤效率。针对玻璃纤维的结构特点以及除雾器过滤水滴的实际情况,将混合丝网的网孔分为标准型、毛刺型和中间型;对于金属丝和标准型网孔的竖直丝,使用描述绕圆柱体气流流动的桑原(Kuwabara)流场模型,其余情况的网丝,使用描述绕平板气流流动的平板流场模型。通过计算粒子在流场中的运动轨迹,获得整体除雾器对水滴的过滤效率。将数值模拟结果与实验测量结果进行了分析对比,两者的吻合程度在合理的范围之内。

In order to study the filtration mechanism of the moisture separator for water droplet of 5-10μm, this paper set up a physical model. For the mixed meshes, they can be classified into three types： standard meshes, bur meshes and middle meshes. For all fibers of the wire meshes and vertical fibers of standard mixed meshes, a Kuwabara flow field is used to track the particle to get the inertial impaction efficiency and then calculate the total filtration efficiency of the meshes. For other fibers, besides the Kuwabara flow field, an around-flat flow field is added to calculate the efficienw. Lastly, the total efficiency of the moisture separator according to the equation of the filtration efficiency for the filters in series is compared with the experimental data. The result shows that, under the standard condition, the calculation value is consistent with the experimental efficiency data.