A reduced-order model of concentration polarization in reverse osmosis systems with feed spacers
A reduced-order model of concentration polarization in reverse osmosis systems with feed spacers
复制标题
具有进料间隔件的反渗透系统中浓差极化的降阶模型
DOI：
10.1016/j.memsci.2023.121508
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发表时间：
2023
影响因子：
9.5
通讯作者：
Molins, Sergi
中科院分区：
文献类型：
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作者：
Johnston, Jacob;Dischinger, Sarah M.;Nassr, Mostafa;Lee, Ji Yeon;Bigdelou, Pedram;Freeman, Benny D.;Gleason, Kristofer L.;Martinand, Denis;Miller, Daniel J.;Molins, Sergi
反渗透系统中的进料间隔器产生复杂的流体流动，这将计算流体动力学（CFD）模拟限制在小的长度和时间尺度。这限制了我们模拟矿物结垢和其他膜污染现象的能力，这些现象发生在更长的长度和时间尺度上。因此，出于动机，我们开发了一个简化的模型，取代了CFD模拟的速度场的分析模型，模仿间隔。这集中在模拟对流扩散方程的溶质运移剩余的数值努力。我们激励和验证模型的CFD模拟和实验室规模的实验中的间隔丝在三个不同的安排，包括情况下的非定常涡流脱落。我们表明，该模型产生了大约10,000倍的加速相比，CFD，准确地再现CFD预测的不仅是平均和最大浓度，而且局部浓度分布沿着膜。我们还展示了用于模拟进料通道的模型，其长宽比为200。该模型提供了一个简单的试验台，探索性研究的多物种运输，降水和膜污染的现象，模拟间隔往往是禁止的。
Feed spacers in reverse osmosis systems generate complex fluid flows that limit computational fluid dynamics (CFD) simulations to small length and time scales. That limits our ability to simulate mineral scaling and other membrane fouling phenomena, which occur over longer length and time scales. Thus motivated, we develop a reduced model that replaces the CFD simulation of the velocity field with an analytical model that mimics spacers. This focuses the remaining numerical effort on simulating the advection–diffusion equation governing solute transport. We motivate and validate the model with CFD simulations and bench-scale experiments of spacer filaments in three different arrangements, including cases of unsteady vortex shedding. We show that the model produces a roughly 10,000-fold speedup compared to CFD, and accurately reproduces CFD predictions of not only the average and maximum concentrations, but also the local concentration distribution along the membrane. We also demonstrate the model for simulating a feed channel with a length-to-height ratio of 200. The model provides a simple testbed for exploratory studies of multispecies transport, precipitation, and membrane fouling phenomena for which simulating spacers is often prohibitive.