Study On Numerical Simulation Of Concentrated Brine Discharged From Desalination Plant

In order to forecast the environmental influence of concentrated brine discharged from desalination plant, one important method is adopted numerical simulation to study the transport of concentrated brine. In the paper, the 3-D multi-mathematical model COHERENS is adopted to simulate the transport and diffusion of concentrated brine into coastal waters. It can provide some guidance to arrangement for desalination plants and power plants projects reasonably, and is useful for designing discharged conditions.The 3-D equations inσcoordinate system are derived from the basic control equations, also gives the methods of solution and procedures. The model is applied to simulate the current of the Bohai Sea, and provide open boundary conditions for the calculation of nesting areas. The advection experiment in the square flume verifies the computing power and reliability of the model in water quality simulation. Adopt the 3-D model to simulate the concentrated brine discharged into ideal flume, the transport and diffusion of temperature, salinity and heavy metals with time is obtained. The results show that the temperature, salinity and concentration of heavy metals present periodic characteristic subjected to the actions of tidal flow, the cycle are roughly the same as the tidal period. And the trend of changes over time in various factors is approximation, the significant different diffusion is not appear.The concentrated brine discharged model is used in the Laizhou Bay, design three experiments on different combinations of temperature and salinity, the transport and diffusion of temperature, salinity and heavy metals with time is obtained. Analyze the influence of different combinations of temperature and salinity of brine discharge on the proliferation status. The results show that the higher temperature is propitious to the spreading of the brine under the same conditions, and increased the salinity is not conducive to the spread of brine, but the too high temperature is bound to increase the thermal pollution areas.Using Matlab draw the flow field and concentration field distribution maps of three factors in horizontal and vertical directions in various time. And compare the regional area of the corresponding concentration of growth. The results show that the distribution patterns of temperature and salinity are closer, in contrast the distribution pattern of heavy metals is quite different.