Simulation Of Hydraulic And Water Quality For Reclaimed Water Supply Network And Economic Analysis

One of the effective way to solve water shortage and water environmentpollution is recycling wastewater, pipe network of which become an important part ofreclaimed water project. It is an important issue of the reclaimed water supply systemmodernization management about application of computer information technologyand adoption of the numerical simulation method to analyze the feasibility of thenetwork operation economy. This paper gives an example of pipe network used todelivery recycle water in a certain area of Tianjin. Based on the example, model willbe built to forecast hydraulic power and water quality change rule in time and spaceaccording to the reclaimed water pipe net dynamic simulation theory, method as wellas the basic information of the reclaimed water project bus, then to inspect theefficiency of pipe network design and operation, and to guide the design and operationof pump station finally to provide the basis for scientific management of reclaimedwater project bus. The main content and conclusions are as following：(1) A micro-hydraulic model is built to calculate pipe network’s hydraulicoperating parameters. The calculated results show that construction capacity ofreclaimed water pipe network is larger and the scale is small at present stage, leadingto the pipe’s flow rate and small pressure-drop, therefore, on the one hand, therecycled water’s factory pressure should be reduced to save energy, on the other hand,the scale of water should be expanded, making the pipe’s flow rate close to theeconomic flow rate as much as possible.(2) Lagrangian time-based approach is adopted to establish dynamic water qualitymodel and then calculate the running condition of four water quality indexrs such asthe residual chlorine, water age, COD and turbidity. In order to ensure the safety ofwater quality, water using should be given better distribution to reduce the water’sresidence time in the pipe network. The results illustrate that users should stop usingreclaimed water if their water age is over60h, and then plant’s chlorine dosage andthe proximal users’ chlorine will be reduced.(3) Cost-price model is used to research the economics of reclaimed water’s busoperators and the cost of investment and operating is analyzed combining TheManagement Measures of Hydraulic Engineering’s Water Price. On the base of that, the profit-loss model about reclaimed water’s bus is built to analyzed economic profitand loss situation about the status quo and planning pipeline network. For reclaimedwater project which is invested and constructed by part, it should be calculated asgains or losses on operations and economic balance of water using in stages so as tomeasure the operations feasibility of market economy in every investment stages. Andguide wastewater’s reuse and distribution economically.