Analysis And Simulation Of Outflow Water Quality In Deep Source Water Reservoir

Reservoir experiences serious eutrophication and high-turbidity water problem when flood inflows, and with the implement of sanitary standard for drinking water, it is urgent need to enhance and predict raw water quality. It is full of important practical value for water treatment plant operation scheduling and automatic control process, reduction of water plant cost, and it has important theoretical significance for reservoir water source protection and restoration.(1) According to the ideas material balance principle of the inflow within the boundaries, builds one dimensional vertical water quality model, develops a one-dimensional selective outflow water quality prediction software. Use the indexes which monitored from2011to2012in nine kinds of working condition to simulate outflow quality. The relative error of dissolved oxygen, electrical conductivity, pH total nitrogen and hardness between simulate results and the measured index of each water quality are within10%; The relative error of redox potential, the chlorophyll concentration and turbidity, CODMn relative to confluence pool measurement indicators are greater than10%.(2) Combine CFD simulation results of the flow field before intake in reservoir with the reservoir vertical water quality, builds outflow water quality model. The simulation results show that dissolved oxygen, electrical conductivity and pH simulation results are most consistent with the measured index in confluence pool, the relative error are within10%; The average relative error of temperature is less than10%, the average relative error of chlorophyll is less than15%, the average relative error turbidity is less than30%. Compared with the former prediction, based on CFD fl field simulation of selective withdrawal outflow water quality model is more accurate (3) Application outflow water quality model based on CFD selective withdrawal for flow field simulation, validate the effect of setting baffle to reinforce selective withdrawal outflow water quality.The simulation results show that:the outflow temperature, PH, conductivity, chlorophyll, turbidity, and dissolved oxygen of no baffle is between setting up baffle, each index is biggest on lower baffle and turbidity is not included,turbidity outflow biggest index is on upper baffle. So setting baffle on the up and down side before the intake can improve outflow quality of water intake through rotating baffle.(4) Application of density underflow model and selective withdrawal outflow water quality model, according to the reservoir biggest operation working conditions, carries out scenario analysis on August27,2011under different working conditions of the floods:The model results show that:direct at water quality distribution of the case at the same inflow temperature and flow, the most profound effect on the outflow quality is under inflow temperature13.5℃, the outflow turbidity is up to greater than1000NTU and outflow temperature is less than15.5℃. Inflow temperature determines the location that inflow flood sneak into the reservoir, the closer the inflow water temperature and orifice water temperature, the higher the outflow water turbidity with the increasing of inflow turbidity under the same. conditions.