Optimization Simulation And Study Of Hydraulic Characteristics On Sewage Sea Diffuser

In recent years, with the development of the economy and the speeding up of urbanization, the wastewater emission is growwing rapidly. On account of the water environment capacity of the land is limited, the surge of effluent discharge has formed a serious challenge to urban water pollution problem. With the deepening understanding of the Marine environment, people found that the ocean has a strong self-purification ability and environment capacity itself. Therefore, sewage discharging into the sea has been becoming one of the effective ways to solve the problem of water pollution in coastal city. The diffuser is an important part in the seaward sewage discharge engineering, the rationality of its structure plays an inportant role to the drainage capacity of diffuser and the degree of impact on the marine environment.Because of the diffuser hydraulic calcuglation process is rather complicated, now combined with a certain seaward sewage discharge engeering, bulid a one-dimensional hydrodynamic model to simulate the diffuser. And then design a hydraulic model test to study the hydraulic characteristics of the diffuser.First, through consulted related literature and refer to the relevant engineering design experience, it introduces the basic theory of the diffuser simply and understand the basic form of diffuser, basic design principles and the calculation method of the basic structural parameters.Secondly, it introduces the flow and transport process of general control equations, and then bulids the one-dimensional unsteady flow pressure pipe network, deduced the solution of the the network control equation and the processing methods of the boundary conditions in detail. Now select a certain pressure pipeline as an example to verify the ability to simulate the pressure pipeline of the modle. The verification results shows that the model can simulate pressure water flow in a pipe network constantly.Thirdly, this paper set up the one-dimensional numerical model to optimize and simulate the sewage sea diffuser, and then determine the diffuser nozzle diameter and spread tube diameter changes eventually. Furthermore, it also verify the drainage capacity of the pipeline under the free head and the final results show that the diffuser have enouth head to meet the requirements of the drainage engineering biggest polluter. Furthermore, this paper designs a hydraulic model test according to the similarity theory, and analysis the characteristics of the diffuser out flow under different working condition combined with the numerical simulation. Then it judges the rationality of the diffuser on accunt of the study the flow law of diffuser.Finally, it studied the seawater intrusion of the diffuser, then calculated the critical invasion flow and critical flushing flow of the sea water. At last, it put forward a series of seawater intrusion prevention measures.