CIESC Journal ›› 2014, Vol. 65 ›› Issue (S1): 377-385.DOI: 10.3969/j.issn.0438-1157.2014.z1.061

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Impact of multiphase and turbulence models on hydrodynamics simulation of commercial flat-sheet MBR

YU Dawei1, WEI Yuansong1, ZHENG Xiang2, FAN Yaobo1, WEI Ding3   

  1. 1. Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China;
    2. School of Environment and Natural Resources, Renmin University of China, Beijing 100872, China;
    3. Technische Universit't Dresden, Freistaat Sachsen Dresden 01069
  • Received:2013-06-01 Revised:2013-12-16 Online:2014-05-30 Published:2014-05-30
  • Supported by:

    supported by the National Natural Science Foundation of China(51278483).

多相流和湍流模型对平板膜生物反应器模拟的影响

郁达伟1, 魏源送1, 郑祥2, 樊耀波1, Wei Ding3   

  1. 1. 中国科学院生态环境研究中心, 北京 100085;
    2. 中国人民大学环境学院, 北京 100872;
    3. Technische Universit't Dresden, Freistaat Sachsen Dresden 01069
  • 通讯作者: 魏源送
  • 基金资助:

    国家水体污染控制与治理科技重大专项(2012ZX07202-002);国家自然科学基金项目(51278483);环境模拟与污染控制国家重点联合实验室(环境水质学实验室)平台启动课题“计算流体力学(CFD)及其在膜生物反应器技术创新中的应用研究”。

Abstract: Phase distribution and velocity field sketch out hydrodynamics characteristics of flat-sheet MBR (membrane bioreactor), which could be analyzed by multiphase and turbulence models efficiently. Aiming at structure optimization, fouling mitigation and energy reduction for MBR, flat-sheet membranes of three major domestic and abroad companies, including Kubota, Toray and SINAP, were chosen to investigate spatial structure of commercial submerged flat-sheet MBR, and to compare effects of different multiphase and turbulence models on phase distribution, velocity field and computational expense. Results showed that the spatial structure of all three flat-sheet membrane was usually designed according to company's manuals, resulting that ratios of length/width and height/diameter were in the range of 1.37±0.63 and 0.97±0.23, respectively. Multiphase model plays key roles rather than turbulence models in phase distribution and velocity field simulation, and the combination of VOF (volume of fluid) and standard k-ε is more accurate and faster for simulating velocity field of submerged flat-sheet MBR. Multiphase model is the key factor of affecting computational costs. On 6 cores platform, VOF consumes 4.5-2.2 times more CPU time than mixture, and realizable k-ε consumes almost the same time as standard k-ε.

Key words: flat-sheet membrane bioreactors, computational fluid dynamics, multiphase flow, turbulence model, experimental validation

摘要: 相分布和速度场是浸没式MBR的流体力学特征的核心,这些特征能够通过CFD的多相流模型和湍流模型低成本、高精度地分析。因此,针对浸没式MBR优化结构、缓解膜污染和降低能耗的需求,以MBR流场的快速准确模拟为目标,以国内外3家主要商用浸没式平板MBR为对象,比较了不同多相流、湍流模型对浸没式平板MBR流场、相分布和计算成本的影响,并进行了模拟验证。结果表明,3家国内外浸没式平板MBR的空间构型多根据厂家推荐值设计,其长宽比为1.37±0.63,高径比为0.97±0.23。商用平板MBR的模拟与验证结果表明:①多相流模型对相分布、流场和速度分布的影响比湍流模型更显著,且VOF模型与standard k-ε的模型组合可更为快速准确地模拟浸没式平板MBR的流场特征;②多相流模型选择是计算成本至关重要的影响因素。6核计算时,VOF模型的CPU 时间为mixture模型的5.5~3.2倍,realizable k-ε的CPU 时间为standard k-ε的1.0~1.1倍。

关键词: 平板膜生物反应器, 计算流体力学, 多相流, 湍流模型, 实验验证

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