Simulation for scale-up of a confined jet mixer for continuous hydrothermal flow synthesis of nanomaterials
Simulation for scale-up of a confined jet mixer for continuous hydrothermal flow synthesis of nanomaterials
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DOI：
10.1016/j.supflu.2014.12.016
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发表时间：
2015-03-01
影响因子：
3.9
通讯作者：
Wang, Xue Z.
中科院分区：
文献类型：
--
作者：
Ma, Cai Y.;Liu, Jing J.;Wang, Xue Z.
研究了用于连续热液流合成纳米材料的密闭射流混合器的反应器性能，并将其从实验室规模扩大到中试规模。应用计算流体动力学（CFD）模型模拟了不同体积放大比（最高26倍）下反应器内热液流体的流动、混合和换热行为。利用ANSYS Fluent软件获得了流动和传热变量的分布，并通过求解物种方程模拟了示踪剂浓度分布。将不同体积放大比下的预测温度分布与现有实验数据进行了比较，得到了较好的一致性。研究了不同放大比下超临界水射流与前驱体流的混合，确定了放大比对水动力和热力学特性的影响。研究结果表明，在中试工厂规模下观察到的混合程度稍弱，但在实验室和中试工厂规模下，动量主导的湍流和相同数量级的混合水平可以导致在所研究的体积放大比和操作条件下生产出类似质量的纳米颗粒，这得到了文献实验观察的支持。(C) 2015 Elsevier B.V.版权所有
Reactor performance of confined jet mixers for continuous hydrothermal flow synthesis of nanomaterials is investigated for the purpose of scale-up from laboratory scale to pilot-plant scale. Computational fluid dynamics (CFD) models were applied to simulate hydrothermal fluid flow, mixing and heat transfer behaviours in the reactors at different volumetric scale-up ratios (up to 26 times). The distributions of flow and heat transfer variables were obtained using ANSYS Fluent with the tracer concentration profiles being simulated via solving the species equations. The predicted temperature distributions under various volumetric scale-up ratios were compared with the available experimental data, and good agreements reached. The mixing between supercritical water jet and precursor stream with different scale-up ratios was examined in detail to identify the effect of scale-up ratios on hydrodynamic and thermodynamic features. The findings indicate that slightly weaker mixing was observed at the pilot plant scales, but the momentum dominated turbulent flow in the reactors and the same order of magnitude of mixing levels at both laboratory and pilot plant size scales could lead to similar quality nanoparticles to be manufactured under the investigated volumetric scale-up ratios and operating conditions, which is supported by experimental observation from literature. (C) 2015 Elsevier B.V. All rights reserved.