Optimization Design And Reliability Analysis Of LBE-cooled Fast Reactor Main Coolant Pump

With the development goal of the Generation IV nuclear reactor set by the International Forum on Nuclear Energy in 2002,fast neutron reactor has become the preferred reactor type of advanced nuclear energy system in the world,representing the development direction of the Generation IV nuclear energy system.The lead-cooled fast reactor(LFR)uses lead or LBE as coolant,and the natural characteristics of lead alloy and the structural design of LFR are combined.The reactor system is the simplest and the number of equipment is the smallest,which constitutes the inherent safety characteristics of LFR.At present,all countries in the world are actively promoting the research and development of LFR.The main work of this paper is to design and study the main coolant pump of the Generation IV lead-bismuth cooled fast reactor based on the parameter requirements of the main coolant pump of the domestic CLEAR-I lead-bismuth cooled fast reactor.1.Since LFR is still in the research and development stage of conceptual design and test reactor,the public information about LFR is mainly summary literature,and the commercial technology literature is almost blank,while the research literature about LFR main coolant pump is less and less.There is no mature design scheme for LFR main coolant pump.The first and second chapter of this paper mainly study the structural characteristics of the LFR reactor and the potential design scheme of primary loop cooling cycle system.Firstly,the natural characteristics of Pb/LBE and the technical problems it may encounter as coolant are studied.Then,the structural characteristics of various LFR reactor types,the arrangement of reactor components and the detailed design scheme of primary loop cooling cycle system are studied in turn,and the basic design requirements of LFR reactor type for the main coolant pump are obtained.Finally,the potential design schemes of symmetrical double outlet volute pump and space guide vane pump are determined as the research object of this paper.2.According to the design requirements of LFR fast reactor,the hydraulic characteristics of two types of main coolant pumps under normal and accident operating conditions are compared and analyzed in all aspects.After synthesizing the possible working conditions of the main coolant pump,it is found that the hydraulic performance of the double outlet volute type main coolant pump is slightly better in the normal pump working conditions,but the space guide vane type main coolant pump has obvious advantages in dealing with the accident conditions.Finally,the space guide vane structure is determined as the design scheme of the LFR main coolant pump.3.In order to improve the hydraulic performance of the main coolant pump and the ability to deal with accident conditions,the multidisciplinary optimization technology is applied to the design of the main coolant pump in the third chapter of this paper.The multi-objective optimization method for parametric design of main coolant pump is proposed.Firstly,the geometric structure of impeller and guide vane is parameterized,and 13 geometric parameters of meridian and radial surface of main coolant pump are taken as design variables.First,the geometry of the impeller and guide vanes is parameterized.Then,the 13 geometric parameters of the meridional plane and the radial plane of the main coolant pump are used as design variables,and the idling performance and hydraulic performance of the main coolant pump are taken as response objectives.Integrating CFturbo,PumpLinx,Matlab and Flowmaster software on the ISIGHT platform,all design processes are organized into one unified and organic framework.Each software can run automatically,and the design process can be automatically restarted to achieve full automation of the entire design process.4.In order to solve the problem that the sample points are discontinuous in the process of sampling optimization and can not find the optimal solution of the whole computational space,based on the optimal Latin hypercube experimental design,the whole constraint space is filled effectively to construct the response network of the constraint space,and then the continuous approximate mathematical model is constructed with the sample points as the training set.Response surface methodology(RSM)and BP neural network are selected to construct the mathematical relationship between input variables and response targets.Then,iterative optimization is completed in constraint space based on muti-objective particle swarm and NSGA-II algorithm.Finally,an excellent hydraulic model with high head,high efficiency,excellent inertia performance and reliable structure is obtained.Then the iterative optimization is completed in the constraint space based on muti-objective particle swarm and NSGA-II algorithm.Finally,excellent hydraulic models with high efficiency,excellent inertia performance and reliable structure are obtained.5.The safe starting characteristics of the main coolant pump are explored based on the bidirectional fluid-solid coupling technology.Firstly,based on the principle of moment balance and energy conservation,the instantaneous speed mathematical model of the main coolant pump during start-up is obtained.Then,the transient load characteristics of the rotor structure under different starting conditions are analyzed,including the variation of the head and the water resistance moment during the starting process,the variation of the transient radial load and axial load of the rotor component,the law of the pressure load distribution of the impeller blade changes with time,the stress distribution of the impeller and the dynamic stress change with time.6.The high temperature test bench with pump operating temperature higher than 300 °C was designed,and the detailed test design scheme was given.The problems of pressure measurement and flow measurement under high temperature conditions were solved,and the high-temperature hydraulic performance test of the main coolant pump was completed.The problems of pressure measurement and flow measurement under high temperature conditions were solved,and the high temperature hydraulic performance test of the main coolant pump was carried out.