Design Optimizaiton Of Parameters For Nuclear Power Plant

Because of its good endurance, high propulsive power, large energy density and free ofoxygen, etc., nuclear power is widely used in ship and aerospace industry. In order to protectthe environment from radioactivity, there are many auxiliary systems in primary loop ofnuclear power plant; steam turbine unit has heavy weight, big volume and low thermalefficiency due to the saturated steam used in secondary loop. In general, the performance ofnuclear power plant is bad in terms of compactness and economics. Therefore, it is significantboth theoretically and practically to reduce the weight, volume and to increase effectiveefficiency of nuclear power plant through optimization technology. In this thesis, themathematic model of main equipments were established for typical nuclear power plantsystem, intelligent optimization algorithm was developed, and optimization case study wascarried out for the purpose of reducing nuclear power plant weight, volume and increasingeffective efficiency of nuclear power plant. The main contents are as follows:1、The physical and mathematical models were set up for steam generator, pressurizer,main steam turbine and main condenser, as well as the mathematical model for thermalequilibrium of nuclear power plant. Corresponding codes were developed with C#language.Given some known parameters, the verification of the codes was performed throughcomparision between the evaluating design and the prototype.2、In the light of multivariables, many constraints and nonlinearity for the optimizationof nuclear power plant, a novel hybrid particle swarm optimization (NHPSO) algorithm wasdeveloped by incorporating the complex shape method with strong ability in local search,genetic algorithm and particle swarm optimization algorithm with good ability in globalsearch. Furthermore, the feasibility-based rule was introduced into NHPSO for the constraintshandling and sorting of the group. The crossover operator was modified and the escape abilitywas improved from local optimal point for complex shape algorithm. The NHPSO algorithmwas tested with8unconstrained test functions,13constrained test functions and3engineeringoptimization problems which are widely benchmarked in the world.3、Case studies were carried out for such single equipment optimization as steamgenerator, pressurizer, main steam turbine and main condenser. In steam generator optimizing design,7optimization variables were selected as follows: operating pressure in primary loop,saturated steam pressure in secondary loop and tube outer diameter in steam generator, etc..Weight optimization, volume optimization and multi-object optimization were performed withNHPSO algorithm. Besides, the coupled optimization of steam generator and reactor core wascarried out by adding some reactor core constraints. For the other three equipments, weightoptimization, volume optimization and multi-object optimization design schemes were alsoachieved after sensitivity analysis and the selection of their respective optimization variables.4、For a certain nuclear power plant prototype, condenser pressure, steam dryness of bothhigh pressure turbine exhaust and low pressure turbine exhaust were selected as theoptimization variables. The reactor power and total steam generated in steam generator wereconstrained within certain ranges. The efficiency was optimized with NHPSO algorithm andthe efficiency was improved by about3.16%.5、In this thesis, proper simplification was made for the nuclear power plant. Theevaluation codes of nuclear power plant were developed by the combination of the codesprovided by other members of the group for the reactor core and reactor pressure vessel. Afterthe key coupling factors were investigated for the whole system, operating pressure inprimary loop, coolant temperature at both core inlet and outlet, saturated steam pressure insecondary loop, and condenser pressure were selected as optimization variables. The weightand volume optimization of nuclear power plant was carried out, and the optimization resultswere analyzed.6、The nuclear power plant optimization design system software has been developed. Thesoftware can serve for such work as follows: nuclear power equipment evaluation,optimization algorithm testing, single nuclear power equipment optimization and system-leveloptimization. In the software, the latest.NET4.0parallel computing technology was adopted,which can accelerate the calculation. The software also preserved interface for the follow-updevice modules. Furthermore, the software has good inheritance, friendly interface and simpleoperation. The software can be applied to the demonstration computation of the existingsystem, and the preliminary design of the new nuclear power plant.The mathematic model setups, evaluating codes development, optimization algorithmimprovement, optimization model consummation, optimization case study, optimizationresults analysis and optimization software development have been accomplished in this theis. To sum up, a relatively complete framework of design optimization of parameters for nuclearpower plant is formulated. All of these are beneficial attempt to the application ofoptimization technology in nulear power plant design and good foundations to furtherresearch on the theories and application of optimization technology.