栅条絮凝池内部流场及颗粒运动状态模拟分析

伏雨; 龙云; 肖波; 程怀玉; 龙新平

doi:10.13205/j.hjgc.202104005

栅条絮凝池内部流场及颗粒运动状态模拟分析

doi: 10.13205/j.hjgc.202104005

伏雨^1,2,
龙云^1,2,
肖波³,
程怀玉^1,2,
龙新平^1,2, ,

1. 水射流理论与新技术湖北省重点实验室, 武汉 430072;
2. 武汉大学动力与机械学院, 武汉 430072;
3. 上海巴安水务股份有限公司, 上海 201715

基金项目:

国家自然科学基金（51679169）。

详细信息

作者简介:
伏雨(1995-),女,硕士研究生,主要从事流动模拟研究。fuyuwhu@whu.edu.cn

通讯作者:
龙新平(1967-),教授,博士生导师,主要从事多流向流动模拟、喷射技术研究。xplong@whu.edu.cn

计量
- 文章访问数: 438
- HTML全文浏览量: 56
- PDF下载量: 25
- 被引次数: 0
出版历程
- 收稿日期: 2020-05-28
- 网络出版日期: 2021-07-21

NUMERICAL SIMULATION AND ANALYSIS OF FLOW FIELD AND PARTICLE MOTION IN GRID FLOCCULATION TANK

FU Yu^1,2,
LONG Yun^1,2,
XIAO Bo³,
CHENG Huai-yu^1,2,
LONG Xin-ping^{1,2
, ,}

1. Key Laboratory of Hubei Province for Waterjet Theory and New Technology, Wuhan 430072, China;
2. School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China;
3. SafBon Water Service Inc, Shanghai 201715, China

摘要

摘要: 利用数值模拟方法对栅条絮凝池前段内部流场进行模拟分析，以涡旋速度梯度和湍动能作为综合评价指标，对其结构设计的合理性进行了验证。在流场中加入了11组不同粒径和有效密度的絮凝颗粒，每组在流场入口处随机释放98560个粒子，利用DPM模型对粒子运动轨迹进行追踪统计。结果表明：随着絮凝颗粒的增大，其有效密度呈相应下降趋势。絮凝颗粒直径为1~1000 μm，沉积率<10%，且在各竖井内沉积均匀，能够很好地满足絮凝要求。当颗粒粒径为1000~5000 μm时，沉积率呈急剧上升趋势，但在各竖井内沉积较为均匀。当颗粒粒径进一步增大至10000 μm时，大量粒子在第1段竖井内沉积，不利于排泥的均匀性。综合考虑沉积率和排泥均匀性，实际工程中应尽量避免出现1000 μm以上的大粒径絮凝体。
- 栅条絮凝池 /
- 数值模拟 /
- 絮凝颗粒 /
- DPM模型 /
- 沉积率
Abstract: Numerical simulation method was used to analyze the characteristics of the internal flow in the front section of the grid flocculation tank. With the vortex velocity gradient and turbulent kinetic energy as the evaluation index of flocculation, the paper verified the rationality of the structural design. In addition, 11 groups of particles with different sizes and effective densities were added to the flow field. Each group randomly released 98560 particles at the entrance of the flow field and their motion was tracked by the DPM model. It was noted that as the particle size increased, the effective density decreased accordingly. The research found that when the particle diameter changed from 1 μm to 1000 μm, the deposition rate was kept less than 10% and the deposition was uniform in each shaft, which could meet the flocculation requirements. When the particle diameter was 1000~5000 μm, the deposition rate increased sharply, but the deposition was uniformed in each shaft. However, when the particle diameter increased to 10000 μm, a large number of particles were deposited in the first shaft, which was not conducive to the uniformity of sludge discharge. So taking deposition rate and the uniformity of sludge discharge into consideration, such large size particles of more than 1000 μm should be avoided in actual engineering practice.
- grid flocculation /
- numerical simulation /
- particle motion /
- DPM model /
- deposition rate

HTML全文

参考文献(24)

[1]	王光. 絮凝、沉降技术在循环水处理过程中的运行总结[J]. 聚氯乙烯, 2017, 45(11):44-47.
[2]	朱昭福. 微絮凝直接过滤工艺在自来水厂扩建工程中的应用[J]. 工程建设与设计, 2020, 11(6):237-241.
[3]	FAN W B, LI W G, GONG X J, et al. Evaluation of the effect of a hydraulic impeller in a flocculation basin on hydrodynamic behavior using computational fluid dynamics[J]. Desalination and Water Treatment, 2014, 54(4/5):1361-1374.
[4]	宋峻林, 唐荣联, 王洪. 絮凝过程CFD数值模拟研究[J]. 现代化工, 2018, 38(8):231-235.
[5]	易中慎. 基于CFD的网格絮凝池参数优化设计研究[J]. 内蒙古科技与经济, 2016, 7(353):117-119.
[6]	陈玉, 王军, 张培璇. 穿孔旋流絮凝池加网格板的数值模拟[J]. 中国给水排水, 2019, 35(1):48-51.
[7]	胡远来, 陆先镭,贺卫宁,等. 排泥管对网格絮凝池流态的影响[J]. 中国给水排水, 2017, 33(23):51-54.
[8]	季小磊. 基于FLUENT对微涡絮凝澄清池的数值模拟及试验研究[D]. 兰州:兰州交通大学, 2019.
[9]	刘存, 王庆涛, 陈翔宇,等. 网格絮凝池结构参数对流场影响的数值模拟[J].水资源与水工程学报, 2018, 29(4):162-167.
[10]	姚萌, 冉治霖, 相会强,等. 搅拌桨叶类型对絮凝池内流场特性的仿真模拟[J]. 环境工程, 2019, 37(增刊1):66-71.
[11]	KHELIFA A, HILL P S. Models for effective density and settling velocity of flocs[J]. Journal of Hydraulic Research, 2010, 44(3):390-401.
[12]	DIERCKS A R, ASPER V L. In situ settling speeds of marine snow aggregates below the mixed layer:Black Sea and Gulf of Mexico[J]. Deep Sea Research Part I Oceanographic Research Papers, 1997, 44(3):390-398.
[13]	FOX J M, HILL P S, MILLIGAN T G, et al. Floc fraction in the waters of the Po River prodelta[J]. Continental Shelf Research, 2003, 24(15):15-17.
[14]	KUPRENAS R, DUC T, KYLE S. A shear-limited flocculation model for dynamically predicting average floc size[J]. Journal of Geophysical Research Oceans, 2018, 12(3):102-154.
[15]	LI Z L, LU P L, ZHANG D J, et al. Simulation of Floc size distribution in flocculation of activated sludge using population balance model with modified expressions for the aggregation and breakage[J]. Mathematical Problems in Engineering, 2019(6):1-10.
[16]	NASSER M S. Characterization of floc size and effective floc density of industrial papermaking suspensions[J]. Separation & Purification Technology, 2014, 12(2):495-505.
[17]	李振亮, 张代钧, 卢培利, 等. 活性污泥絮体粒径分布与分形维数的影响因素[J]. 环境科学, 2013, 34(10):3975-3980.
[18]	黄忠钊, 谭立新. 基于群体平衡模型的污泥絮凝-沉降三维模拟[J]. 西安理工大学学报, 2013, 29(4):469-474.
[19]	仲崇军. 基于CFD的水处理网格絮凝池优化设计研究[D]. 武汉:华中科技大学, 2009.
[20]	XIANG P, WAN Y H, WANG X, et al. Numerical simulation and experimental study of electrocoagulation grid flocculation tank[J]. Water Science & Technology, 2018, 78(4):786-794.
[21]	MARCHISIO D L, VIGIL R D, FOX R O. Implementation of the quadrature method of moments in CFD codes for aggregation-breakage problems[J]. Chemical Engineering Science, 2003, 58(15):3337-3351.
[22]	SAMARAS K, ZOUBOULIS A, KARAPANTSIOS T, et al. A CFD-based simulation study of a large scale flocculation tank for potable water treatment[J]. Chemical Engineering Journal, 2010, 162(1):208-216.
[23]	邹秋兰. 栅条絮凝池栅条间距对絮凝水力条件的影响研究[J]. 工程与建设, 2016, 30(3):333-335.
[24]	MCCAVE I N. Size spectra and aggregation of suspended particles in the deep ocean[J]. Deep Sea Research, 1984, 31(4):329-352.