多级液体分布器流动特性分析

Analysis of flow characteristics of multistage liquid distributor

新型污水处理工艺的处理效率受到反应池流场扰动影响较大,引起流场扰动的主要因素是液体分布器出流均匀性和出孔湍流强度。目前,关于分布器均匀布水的研究较少,尚未揭示淹没流的孔口阻力特性与沿程阻力特性协同机制。本文提出一种孔径梯度变化的多级液体分布器结构,应用于某示范工程中,建立了基于物质传输模型的淹没流液体分布装置有限元分析方法,将数值模拟结果与试验结果进行对比。结果表明:试验得到2个测试平面内氯离子质量浓度最大偏差为1.97%,有限元模拟得到多级液体分布器的克里斯琴森均匀系数为89.1%。在进水过程中,试验和有限元模拟所得新进水质量分数的变化趋势一致,结果吻合较好,证明了新型污水反应器结构的合理性,且满足工程应用要求。

The treatment efficiency of the new wastewater treatment process is greatly affected by flow field perturbation in reaction pools,primarily caused by the outflow uniformity and the turbulence intensity at the outlet pores in liquid distributors.At present,research on the uniform water distribution by distributors is sparse,and the synergistic mechanism between the orifice resistance characteristics and the along-stream resistance characteristics in submerged flow has not yet been revealed.In this paper,a multi-stage liquid distributor structure with a gradient change in aperture diameter was proposed and applied in a demonstration project.A finite element analysis method for the submerged flow liquid distribution device,based on the species transport model,was established.Numerical simulation results were compared with the test results.It showed that the maximum average deviation of the chloride ion concentration in the two test planes was 1.97%,and the finite element simulation yielded a Christiansen s uniformity coefficient of 89.1%for the multi-stage liquid distributor.During the influent process,both the test and finite element simulation showed consistent trends in the change of the new influent quality fraction and the results were aligning well with each other.This proved that the new wastewater reactor structure was feasible enough to meet the requirements for engineering applications.