微涡旋絮凝及其澄清数值模拟、机理研究与参数优化

The vortex clarification technology which is developping by East China Jiaotong University has been of great benefits to "kiloton million people" - - - - - a project of water supply for villages and towns (rural drinking water safety project) in Jiangxi. However, in the application of the project，the design and selection of operating parameters of reactor tend to be blind and arbitray..For better use of the technology, the research project will use Fluent to simulate the flow of vortex scale、vortex distribution and flow filled state in the reactor. Also it tests the flocs zeta potential and shape change and then make a contrast between the vortex scale, energy distribution and grid flocculation test, which should be done with the help of fractal theory and from the point of view of dynamics revealing vortex flocculation mechanism. Through Fluent 's simulating the fluid state and the test of turbidity , floc grain diameter and other parameters of water quality, research has be done on the effect of the vortex current time of reactor, parameters of inclined tube structure, and other parameters such as hydraulic load of surface、 mud index, reflux ratio and etc. in normal temperature and turbidity , low temperature and turbidity, water quality of micro-polluted source on the flocculation and clarification. The research applies compound target algorithm and studoes in depth the vortex clarification mechanism. It aims to establish more sophisticated mathematical models and more advanced mathematical algorithm theoretically, optimize the reactor under the its working conditions of design and operation parameters, develop water vortex clarification techniques of efficiency, low cost and suitable for our countryside at the present which has independent intellectual property rights. And the research provides technical support to solve the problems of high energy consumption and low efficiency that the clarifier tank encountered in application.

华东交大正在研制的涡旋澄清技术在江西推行的"千吨万人"乡镇供水计划中显示出良好的经济、社会效益。然而在工程应用中，反应器在设计、运行参数的选取上还存在着较大的盲目性及随意性。.为深入研究及利用该技术，课题将对水流在反应器中的涡旋尺度、涡旋分布及流场状态进行数值模拟分析；检测絮体ζ电位及其形状变化，在涡旋尺度、能耗分配上与网格絮凝作对比；结合分形理论，从水动力学上揭示微涡旋絮凝机理。通过流态数值模拟，测试浊度、絮体粒径等参数，研究反应器的涡流时间、斜管结构参数、表面水力负荷、回流比等参数对絮凝及澄清效果的影响，结合涡旋絮凝理论、浅池理论、泥渣悬浮层理论等，运用多目标算法，从系统及整体上研究涡旋澄清机理。通过机理研究、数值模拟分析及试验测试，优化反应器在常温常浊、低温低浊、微污染进水水质时的设计及运行参数，研制具有自主知识产权的经济高效低耗且适合现阶段我国（特别是江西）农村供水的涡旋澄清技术。

在上一个结题基金项目（50868005）中，课题组成功开发出HJTM1、HJTM2及HJTM3型涡流反应器。本项目则从理论及试验上进一步研究了该技术，对水流在反应器中的涡旋尺度、涡旋分布及流场状态进行了数值模拟分析；通过检测絮体ζ电位及其形状变化，在涡旋尺度、能耗分配上与网格絮凝作对比，得出微涡旋絮凝更接近絮体碰撞半径，絮凝效果更好的结论。通过流态数值模拟，测试浊度、絮体粒径等参数，研究了反应器的涡流时间、斜管结构参数、表面水力负荷、污泥回流比等参数对絮凝及澄清效果的影响。通过机理研究、数值模拟分析及试验测试，在涡旋网格絮凝的微涡流混凝技术及浅池理论基础上，研发了具有自主知识产权的经济高效低耗且适合现阶段江西农村供水的涡旋澄清技术。该技术主要基于微涡流絮凝反应、斜板/管沉淀分离和污泥浓缩理论。技术的核心是在絮凝区设置了2-3个涡流反应室，各涡流反应室内放置了根据原水水质而设计的不同规格的涡流网格絮凝反应器；各反应室涡流反应时间、涡流区设置高度以及涡旋网格絮凝反应器的组合搭配顺序根据处理原水水质而设计；在分离室内设置用于提高沉淀效果的由若干倾斜设置的斜管或斜板，沉淀区的表面负荷可按7~15m3/m2•h设计。然后通过试验进一步优化了涡旋高效澄清反应器在不同进水水质时的设计及运行参数，为下一步工程运用及推广提供了科学依据及数据支持。该技术目前已应用于江西省内外多个工程项目中，不仅出水水质达标，而且投资小，运行成本低，显示出良好的经济、社会效益及应用前景。