多纤维捕集过程中细颗粒湍流团聚模拟研究

基于随机多层纤维过滤介质算法建立了平板式三维拟态化结构.利用计算流体力学-颗粒群平衡模型（CFD-PBM）对多纤维捕集过程中细颗粒湍流团聚进行数值模拟研究，并采用分区法求解颗粒群平衡方程（PBE）.通过控制变量法分析表明：多纤维捕集过程中存在着明显的颗粒团聚行为.粉尘颗粒的团聚程度随停留时间增加而增强，当t ≥ l/v（速度方向模型尺寸长度/入口风速），团聚逐渐趋于稳定；当v_max·t ≤ l，入口风速越大，颗粒团聚程度和团聚速率越大，最终的团聚程度取决于入口风速和停留时间；颗粒粒径越大，粉尘颗粒的团聚程度和团聚速率越小.出口颗粒平均粒径与初始粒径相比增长倍数越小.粉尘颗粒体积分数越大，颗粒团聚程度以及团聚速率越大.当v=0.1m/s，d_p=1.0μm，VF >0.003636，Bin-7~Bin-0区间数量浓度对数分布呈线性比例关系.

Study on turbulent aggregation characteristics in the process of fine-particle captured by multi-fiber

This paper established the flat 3-D mimic structure that was based on the random multi-fiber filter media algorithm. The computational fluid dynamics-population balance model (CFD-PBM) was used to simulate the turbulent aggregation of fine particles during the multi-fiber capture. The partition method was used to solve the population balance equation (PBE). The analysis by the controlled variable method shows that there was apparent particle aggregation behavior in the multi-fiber capturing process. The particle aggregation degree increased with the increasing residence time and gradually stabilizes while t ≥ l/v (dimensional length along with the flow field direction/inlet velocity). When v_max·t ≤ l, the larger the velocity inlet, the larger the particle aggregation degree and the aggregation rate, but the final aggregation degree depends on the velocity inlet and residence time; the larger the particle diameter, the smaller the particle aggregation degree and the aggregation rate. Also, the smaller the ratio of the average particle diameter of the outlet compared with the initial particle diameter. The larger the volume fraction of dust particles, the larger the particle aggregation degree and the aggregation rate. When v=0.1m/s, d_p=1.0μm, VF >0.003636, the number concentration logarithmic distribution between Bin-7~Bin-0 shows a linear proportional relationship.