单纤维捕集过程中亚微米颗粒的布朗团聚

张俪安; 刁永发; 楚明浩; 王如歌; 沈恒根

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中国环境科学 ›› 2021, Vol. 41 ›› Issue (4) : 1548-1554.

大气污染与控制

单纤维捕集过程中亚微米颗粒的布朗团聚

张俪安, 刁永发, 楚明浩, 王如歌, 沈恒根

作者信息 +

Brownian aggregation in the process of submicron particles captured by single fiber

ZHANG Li-an, DIAO Yong-fa, CHU Ming-hao, WANG Ru-ge, SHEN Heng-gen

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摘要

针对亚微米颗粒（0.1~0.5μm）在单纤维捕集过程中的布朗团聚规律，基于计算流体动力学-颗粒群平衡模型（CFD-PBM）对粉尘颗粒在单纤维捕集过程中的布朗团聚行为进行了数值模拟研究，采用分区法对颗粒群平衡方程（PBE）进行求解，综合考虑了停留时间、入口粉尘粒径、气流温度、Pe数对布朗团聚的影响，并将数值模拟与实验结果进行对比.结果表明，布朗团聚核UDF符合数值模拟计算要求.粉尘颗粒的布朗团聚贯穿整个过程，团聚有效时间t=L/v（速度方向模型尺寸长度/入口流速）；粉尘颗粒越小，布朗团聚越强，Bin-7与Bin-0区间的数量浓度差距越小，粒径与布朗团聚强度呈负相关；气流温度是通过改变气流动力黏度以及聚并系数来影响布朗团聚，与布朗团聚强度呈正相关，当T=300K，d_p≥0.5μm时，颗粒的布朗团聚效应可以忽略；Pe数通过扩散系数的变化影响布朗团聚，与布朗团聚强度呈负相关.

Abstract

In view of the Brownian aggregation law in the process of submicron particles (0.1~0.5μm) captured by single fiber, the Brownian aggregation behavior in the process of the dust particles captured by single fiber was numerically studied based on computational fluid dynamics-population balance model (CFD-PBM), and the partition method was used to solve population balance equation (PBE). The effects of residence time, inlet particle diameter, airflow temperature, and Pe number on the Brownian aggregation were considered comprehensively, and the numerical simulation and experimental results were compared. The results showed that the Brownian aggregation kernel met the requirements of numerical simulation calculation. The Brownian aggregation of dust particles run through the entire process, aggregation effective time t=L/v (dimension length along with flow field direction/face velocity). The smaller the dust particles, the stronger the intensity of the Brownian motion, the smaller the number density gap between Bin-7 and Bin-0, and the particle diameter was negatively correlated with the Brownian aggregation intensity. Brownian aggregation was affected by airflow temperature by changing flow field dynamic viscosity and aggregation coefficient, which was positively correlated with the Brownian aggregation intensity, when T=300K, d_p ≥ 0.5μm, the Brownian aggregation effect of particles can be ignored; Brownian aggregation was influenced by the change of Pe number through the change of diffusion coefficient, which was negatively correlated with the Brownian aggregation intensity.

导出引用

张俪安, 刁永发, 楚明浩, 王如歌, 沈恒根. 单纤维捕集过程中亚微米颗粒的布朗团聚[J]. 中国环境科学. 2021, 41(4): 1548-1554

ZHANG Li-an, DIAO Yong-fa, CHU Ming-hao, WANG Ru-ge, SHEN Heng-gen. Brownian aggregation in the process of submicron particles captured by single fiber[J]. China Environmental Science. 2021, 41(4): 1548-1554

中图分类号： X513

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