The Dynamic Simulation Of Quality In Water Supply Network

Nowadays, more and more problems of water quality have happened in water supply networks in our country, furthermore, the criterion of water quality in network becomes stricter than before. We can get the state of chlorine of all nodes at every time step by modeling chlorine's decay in network dynamically. And it will be the theoretical foundation of administration of network.At first, a model of residual chlorine decay in network is discussed. The model discusses the consumption of chlorine reacting with chemicals and microbes in bulk water, with biofilms on the pipe wall, in the corrosion process, besides, the mass transport of chlorine from bulk water to pipe wall is considered too. The model of residual chlorine decay is modeled as a simply first-order decay reaction.Then, approaches of modeling water quality in network are introduced. These are Eulerian Finite-Difference Method, Eulerian Discrete Volume Method, Lagrangian Time-Driven Method, Lagrangian Event-Driven Method. TDM is used in this model. This method divides the water in pipes into a series of nonoverlapping segments. At the end of every time step, the water quality in these segments is updated. Then the method tracks the concentration and size of these segments that fill each line of the network. So water quality in network is modeled dynamically.At last, we use the software MATLAB, which is used in the field of science and technology, and the database software ACCESS to design the program. At the foundation of modeling of hydraulic in the network, the residual chlorine decay in 24 hours in a city is modeled dynamically. Then the maps of residual chlorine line and residual chlorine area will be produced, which provide the scientific foundation for operation, management, monitoring, finding ways in improving water quality of network.