Study On Optimization Of Water Distribution System Of Super Large Cooling Towers In Nuclear Power Plant

Along with the development of nuclear power in China,inland nuclear power plants will become one of the important developing trends in future.For the 1000 MW nuclear power plant,ultra-large cooling tower will probably be applied.The uniformity of water distribution plays an important role for the cooling effect of cooling tower.Uniformity of water distribution will directly affect the coefficient of fill utilization and the outlet temperature of cooling tower.At present,domestic and foreign study of water distribution calculation and optimization mainly focus on the uniformity and thermolysis effect of cooling tower.But the method to achieve a lower uniformity coefficient through efficiently adjusting for the water distribution piping has not been developed.Therefore,according to the characteristics of the super-large cooling tower in the nuclear power plant,based on hydraulic calculation of the water distribution system,considering the reflective and rotating nozzle types,with design methods of the whole tower uniformed water distribution,uniformed water distribution of each partition as well as single and double shaft and other typical arrangements of super-large cooling tower,appropriate intelligent optimization algorithms was chosen to study optimization method with pipes of different diameters arranged and selected automatically in order to quickly and accurately obtain more uniformed water distribution optimization designs,which is of great value optimal and significance to improve the thermal efficiency of super-large cooling tower,the overall design of the cold-end system,and the selection of equipment in the cold-end system.Hydraulic calculation methods and related mathematical models of water distribution systems for super-large cooling towers in nuclear power plant were reorganized and improved,based on the theoretical analysis and mathematical derivation.Research and analysis were made on hydraulic resistance characteristics of water distribution pipe.A simplified calculation method of water distribution system was developed.Aimed on the uniformed water distribution of the whole tower and uniformed water distribution of each partition of the tower,the ideal flow coefficient characteristics of distribution pipes were analyzed.And optimization methods and mathematical models were proposed and established for water distribution system design based on genetic algorithms.Finally,the calculation and comparison were made to verify the correctness and validity of developed models with the project example.