氯接触池中溶质输移与消毒过程的数值模拟

Numerical modeling of disinfection processes in chlorine contact tanks

为使饮用水处理中氯接触池达到较高的掺混和消毒效率 ,提出一种数学模拟方法。采用二维水流动量方程和连续方程、自由氯的反应过程一阶动力学方程和细菌数量衰减过程的 Chick- Watson公式等组成的模型 ,计算了氯接触池中溶质输移与消毒过程。对 3种涡粘性湍流模型与 3种差分格式的不同组合下计算所得到的多组模拟结果进行了分析 ,并与试验数据进行了比较。研究表明 :通过数值方法对池内的水流紊动结构及自由氯输运、反应和细菌生灭等过程进行计算模拟 ,与仅依据不同设计方案所得滞留曲线进行评价的做法相比 ,更有利于比较内部细节的设计 。

The hydraulic efficiency of potable water disinfection in chlorine contact tanks is related to basic fluid dynamics processes, such as turbulent flow, solute transport, chemical reactions and biological decay. Both the turbulent flow and the transport processes within the tanks must be accurately simulated to estimate the mixing and disinfection efficiency of the chlorine solute for the design of treatment facilities. The key part of a numerical simulation is the accuracy of the advection and shear stress computations. This paper compares various combinations of turbulence models and difference schemes as they predict the solute transport patterns and the flow-through curves (FTC) in a realistic tank configuration with physical model measurements. The simulation techniques provide more detailed information on the hydrodynamic and solute transport characteristics in the tank, than that found using only the FTC method.