| Nuclear power units have the characteristics of clean,emission free,stable performance and low operating cost,which play an important role in China’s energy structure.During the commissioning of the service water system(sea water circulating cooling)of Haiyang nuclear power plant,it was found that there was a large gap between the actual maximum flow and the design flow of the system.Taking the service water system as the research object,this paper analyzes the flow characteristics of the system by means of experimental research,theoretical calculation and numerical simulation,and provides a feasible reconstruction scheme.The main research contents are as follows:1.Carry out experimental research on service water system,explore the flow characteristics of pipeline system under different working conditions,obtain the resistance characteristic curve of system and pipe network,analyze and get three main reasons for low system flow:low pump power,large flow resistance of equipment,and large local resistance of pipeline.2.The theoretical calculation and experimental research of the circulating water pump are carried out,the actual performance curve of the pump is determined,and the transformation scheme of the pump impeller is provided,which is conducive to improving the efficiency of the pump.3.Analyze the flow resistance characteristics of the pipe network equipment,and find that the flow resistance of the system automatic backwash filter is too large.Explore the feasibility of reducing the flow resistance from the direction of expanding the inner diameter of the pipeline,and provide two reconstruction schemes to reduce the flow resistance.4.The numerical modeling analysis of the bulge structure in the pipeline is carried out,and the local flow resistance characteristics caused by the hot melt bulge are obtained,which provides a feasible reconstruction scheme.5.From the aspects of reconstruction efficiency,construction period and economy,this paper compares three schemes of reducing flow resistance and increasing flow and selects the best scheme combination. |
