基于栅条式微涡絮凝的隧道废水处理技术数值模拟  

Numerical simulation study of tunnel wastewater treatment technology based on grating-type micro-vortex flocculation

作　　者：张东海 ZHANG Dong-hai(China Railway First Survey and Design Institute Group Co.Ltd.,Xi’an 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,陕西西安710043

出　　处：《兰州理工大学学报》2024年第1期68-75,共8页Journal of Lanzhou University of Technology

基　　金：中铁第一勘察设计院集团有限公司项目(院科**20-26)的资助。

摘　　要：为探究微涡混凝技术在隧道废水处理工艺上的可行性,通过数值模拟手段对不同特征的栅条式微涡发生器所产生的混凝流场特性进行了研究,并采用最优组合形式对浊度为1300 NTU模拟隧道废水进行了水力絮凝验证实验.结果表明:栅条的粗细主要影响流场内流体湍动能及湍耗散的在初始混凝阶段的消耗程度,边长为5 mm的方形栅条更容易维持整个流场内混凝过程中所需的动能;栅条布置间距会改变栅条对流体的阻滞作用,布置间距为11mm时,流体能在反应中后段提供更高的湍动能及湍耗散用于絮凝反应;栅条的长度主要影响流场在轴向方向的能量演变情况,400、600、800 mm的栅条会延长流体在流场内的能量分配距离,使反应器中后段的絮体也能够有足够用于聚集的能量.采用最优组合形式的栅条对浊度为1300 NTU模拟隧道废水进行了水力絮凝验证实验,废水最终出水浊度可稳定在50 NTU以下.To explore the feasibility of micro-vortex coagulation technology in tunnel wastewater treatment process,a numerical simulation is conducted to investigate the the characteristics of the coagulation flow field produced by the grid micro vortex generator with different characteristics.Furthermore,a hydraulic flocculation validation experiment is conducted using the optimal combination of grating-types for simulated tunnel wastewater with turbidity of 1300 NUT.The results show that the thickness of the grid bars primarily affects the turbulent kinetic energy of the fluid in the flow field and the consumption degree of turbulent dissipation in the initial coagulation stage.The square grid bars with a side length of 5 mm are better suited to maintain the kinetic energy required in the whole coagulation process in the flow field.The spacing of the grid bars alter their blocking effect of the grid bars on the fluid.When the spacing is 11 mm,the fluid can provide higher turbulent kinetic energy and turbulent dissipation for flocculation reaction.The length of grid bars mainly affects the energy evolution of the flow field in the axial direction.The grid bars of 400 mm,600 mm and 800 mm extend the energy distribution distance of the fluid in the flow field,providing sufficient energy for aggregation of the flocs in the rear section of the reactor.The hydraulic flocculation verification experiment of simulated tunnel wastewater with turbidity of 1300 NTU was carried out using the optimal combination of grid bars,resulting in a stable effluent turbidity of the wastewater of less than 50 NTU.

关 键 词：涡旋絮凝技术 数值计算 栅条式微涡发生器 湍动能 湍耗散 

分 类 号：X703[环境科学与工程—环境工程]