2021年12月，化学工程领域二区期刊《Chemical Engineering Science》刊登了课题组张鑫博士的最新成果：Simplified model for the calculation of the particle-capture process in air filter media（https://doi.org/10.1016/j.ces.2021.117358）。

原文连接：https://www.sciencedirect.com/science/article/pii/S0009250921009234?via%3Dihub

第一作者：张鑫，环境科学与工程学院，博士；

通讯作者：刘俊杰教授，博导。

研究亮点：

1.首次采用几何学和拓扑学的方法来研究单纤维的颗粒沉积过程；

2.提出了一种过滤介质全生命周期性能的简化计算方法；

3.提出了影响纤维表面颗粒沉积形态的关键影响因素。

1. Describe single-fiber particle-capture process by geometric and topological methods.

2. Propose a simplified calculation method of filter media life cycle performance.

3. Propose influencing factors of particle accumulation morphology.

摘要：

纤维过滤材料广泛应用于个体防护和空气净化，比如疫情期间常用的口罩和办公室、住宅、汽车和飞机座舱等封闭空间的空调系统，我们依赖纤维过滤材料来保证舱室内的环境健康和舒适。过滤材料在捕集颗粒过程中的性能变化，尤其是阻力的变化，对空调系统的能耗和洁净空气的输送量息息相关。由于颗粒物的动态捕集过程很复杂，很难通过计算机模拟的方法快速获得。在这项研究中，我们通过几何学和拓扑学的方法提取纤维表面沉积的颗粒物的特征（考虑拦截效应、惯性效应和扩散效应的三种捕集机理），并由此建立起简化的单纤维颗粒沉积模型。通过CFD模拟，我们计算了不同颗粒捕集阶段的纤维阻力。并和文献中采用CFD方法（3D非简化模型）、LB-DEM方法的结果进行了对比，证明该简化模型可以实现颗粒捕集过程的阻力计算。由于该简化模型不需要对每个颗粒物进行受力分析，大大节省了计算资源。我们同时发现对于扩散捕集的颗粒物，其在纤维表面的沉积密度对其阻力有较大影响，采用2D纤维模型不能很好地反映其捕集颗粒后的阻力变化。而对于主要依靠拦截作用捕集的颗粒，需要同时考虑惯性作用，这两种作用的比值是影响阻力的关键因素。

It is difficult to quickly calculate the performance of the air filter media, especially regarding the dynamic particle-capture process. In this study, the geometric and topological features of the existing particle-deposition morphologies based on three different particle-capture mechanisms (diffusion, inertia, interception) were extracted, and a single-fiber particle-deposition model was established. Through a computational fluid dynamics (CFD) simulation, the resistances in different particle-capture stages were calculated, and it was proved that the model can realize rapid calculation of the dynamic particle-capture process. Since no force analysis of particles is required, calculation resources were greatly conserved. Based on this, the study found that for diffusion, the packing density (Sp) of the deposited particles has a large impact on the resistance, subsequently leading to underestimation of the resistance by the two-dimensional (2D) model. Interception needs to be considered with inertia, and the ratio of the two (I/R) is the key factor that affects the resistance.

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