Three-Dimensional Numerical Simulation On Thermal Discharge Of Coastal Power Plant

With the progress of economy in our country, the demand for electric power is extremely increasing in our daily life. Thus, a multitude of power plants, such as thermal or nuclear power plant, have been built in coastal regions, and the way of cooling water always is to outfall the thermal water to the surface of ocean. But the heat exchanges between natural water and cooling water always caused water temperature rise in some degree in power plants area, and bring a certain extent influence to ecological environment. Likewise, in order to ensure the normal running of power plants, cool water has to be obtained by thermal power plant. Therefore, it is necessary to analyze the area and amplitude of water temperature-rise caused by thermal discharge, make correct environment assessment invoked by the cooling water, and provide scientific references for the design of water intake and outfall.The main method to study thermal discharge is combination of physical models and numerical simulation method. Currently, Two-dimensional numerical simulation always used to predict water temperature rise in large areas, and the results of which mainly supply service to environment assessment and offer hydrodynamic condition for physical model test. But Two-dimensional numerical simulation does not accurately reflect three-dimensional features of temperature-rise distribution in project area. Thus, physical model test, which consume a huge of manpower, material and financial resources, was adopted to simulate water temperature-rise in the near.field of engineering to reflect three-dimensional feature of thermal discharge.In this thesis, three-dimension mathematical model has been used to simulate the regulation of current and water temperature transportation in order to overcome the shortcomings of two-dimensional numerical simulation and physical model test. By this means, more accurately prediction of thermal discharge can be realized.The main context and results may be summarized as follows:(1) On the basis of collating and analyzing relevant literature, in-depth understanding of research methods and research status in recent years, find the research value and method of this paper.(2) By carefully studying on ECOMSED program, take advantage of three-dimension nonlinear hydrodynamic module and heat flux module to simulate thermal discharge.(3) Based on the careful analysis of hydrological data about Luoyuan bay, utilizing ECOMSED model’s three-dimension nonlinear hydrodynamic module and heat flux module to simulate the current and temperature field in the project area. (4)A simulation of spring tide, middle tide and neap tide current filed nearby the power plant was carried out, and the results of velocity distribution at different depth were compared with the hydrological data of prototype observation.(5)ECOMSED model was applied to simulate the water temperature-rise under the operation condition of power plant, and the simulation results were compared with the data of prototype observation.(6) Three-dimensional numerical simulation of thermal discharge about Kemen power plant has been carried out. The calculation results were present as follows:the maximum temperature-rise envelope, the average temperature-rise counter map, the process line of intake water temperature-rise, and vertical distribution in typical points of spring tide and neap tide.(7)Comparison of numerical simulation results and practical measured values, it can be find that ECOMSED model could properly reflect the three-dimensional feature of current and temperature distribution, and be used to simulate water temperature’s variation in cooling water projects in future.