基于改进絮体检测与跟踪的微涡流絮凝工艺复杂流态可视化与过程模型研究

There are lots of problems in micro-vortex flocculation process of water treatment. For example, the method of identification, detection and tracking of flocculation is complex and poor effectively, real flow cannot be reflected truly because of only considering liquid phase and ignoring solid phase, and micro-vortex flocculation inherent law is unclear. Aiming to the above problems, the project group intend to use Canny and Watershed Algorithm to proceed edge detection so as to gain accurately floc characteristic parameters including quantity and fractal dimension. And multi-target tracking is achieved by Fruit Fly Optimization Algorithm based on BP Nerve Network to obtain floc moving velocity quickly and accurately. Flow Visualization is acquired by numerical simulation and flocculation tracking to reveal distribution of flow field under solid-liquid two-phase complex flow, which could optimize hydraulic condition and obtain some key parameters e.g., flow velocity, tubulence kinetic energy, dissipated energy and vortex scale. The micro-vortex flocculation process model among the floc relative scale, characteristic parameters and effluent turbidity is established to further reveal the inherent law of flocculation. The research results have important theoretical value and practical significance to optimize the management of vortex flocculation treatment, improve water quality and ensure the safety of drinking water.

在水处理微涡流絮凝工艺研究中，絮体的识别、检测与跟踪方法运算复杂、效果欠佳，仅关注液相（水）而忽略固相（絮体）的单相流流场分布，存在无法准确反映其真实流态、内在规律不明等问题，拟采用 Canny及分水岭等算法进行边缘检测，准确获取絮体数量、分形维数等特征参数；采用基于BP神经网络的果蝇优化算法实现多目标跟踪，以快速准确得到絮体运动速度；通过絮体跟踪与数值模拟相结合，实现流场可视化，揭示微涡流絮凝工艺固液两相复杂流态下的流场分布规律，优化水力条件；获取流场流速、湍动能、能耗散和涡旋尺度等关键信息，建立融合絮体相对尺度、特征参数和出水浊度之间的微涡流絮凝工艺过程模型，进一步揭示絮凝内在规律。项目研究成果对优化微涡流絮凝工艺运行管理、节省絮凝剂投加量、提高出水水质、保障居民的饮用水安全具有重要的理论价值与实用价值。

针对水处理微涡流絮凝工艺中絮体的识别、检测与跟踪方法运算复杂，流场分布无法准确反映其真实流态、内在规律不明等问题，本项目主要研究内容及成果如下。.（1）提出了一种基于BP神经网络的果蝇优化算法，获取了更快速准确检测出絮体数量、分形维数、絮体强度、密实度、絮体粒度等性能参数以及絮体运动速度等的改进絮体检测与跟踪方法，实现了絮体多目标跟踪，提高了寻优速度及检测精度。.（2）研制了水处理吸附和催化功能性材料，并应用于微涡流絮凝预处理和后处理；利用CFD数值模拟软件对絮凝过程的固-液两相复杂流态进行数值模拟研究，得出速度和能量矢量图及云图，对湍动能、能耗散等影响进行分析，实现了微涡流絮凝工艺固-液两相复杂流态可视化流场及絮体可视化运动轨迹可视化，进一步揭示了固-液两相复杂流态下的絮凝流场分布规律，优化了微涡流反应器及微涡流絮凝池池型结构。.（3）将絮体检测与跟踪算法获取的各项絮体特征参数，与数值模拟获得的流场信息相结合，建立了多源数据融合的絮凝过程模型，揭示了微涡流絮凝工艺的内在规律，优化了微涡流絮凝工艺运行管理，节省了絮凝剂投药量。.研究结果对揭示微涡流絮凝工艺的内在规律、优化微涡流反应器及微涡流絮凝池池型结构设计、指导微涡流絮凝工艺运行管理、提高水处理絮凝效果、保障居民的饮用水安全具有重要意义。