Dual-objective optimization of the thermodynamic efficiency and the volume of the nuclear power plant

Searching higher thermodynamic efficiency of the nuclear power plant is a continuous quest in the field of nuclear engineering. Both increasing the thermodynamic efficiency, and decreasing the volume of the nuclear power plant can not only improve the economy, but also reduce the difficulty of manufacture and installation of large components. It has been considered important to apply optimal algorithm to study the dual-objective optimization design of the nuclear power plant, aimed at optimizing the thermodynamic efficiency and the volume of the nuclear power plant, by finding the design parameters' optimal combination for the nuclear power plant. A combined evaluation-optimization model was developed and the dual-objective optimization design of the nuclear power plant was studied to optimize the thermodynamic efficiency and the volume of the nuclear power plant, while satisfying the given structural, performance and security constraints. An optimizer module based on the genetic algorithms has been coupled with a dual-objective evaluation model of the nuclear power plant, including both a thermodynamic efficiency calculation model and a volume evaluation model, written in C sharp According to equivalent heat drop theory, a matrix method of calculating the mass flow of each extraction steam was given. Then, the thermodynamic efficiency of the nuclear power plant can be computed. The volume estimation model includes the self-developed mathematical models of the feedwater heaters, the moisture separator reheater, the reactor coolant pump. Other mathematical models of major units which have been developed by the team are also included, i. e., the reactor core, the steam generator, the pressurizer, the reactor coolant pipeline, the reactor pressure vessel, the condenser and the turbine. The coupling relationship between the units was considered in the dual-objective evaluation model. In the dual-objective optimized results, while satisfying the given structural, performance and security constraints, the thermodynamic efficiency of the nuclear power plant increases almost 1.5% and the volume of the nuclear power plant decreases almost 10.3%. The results show that there is a great deal of potential in decreasing the volume of the nuclear power plant, while satisfying the given constraints. Meanwhile, the thermodynamic efficiency of the nuclear power plant is also improved in the optimized results. The corresponding optimized results and the analysis on the optimized thermodynamic efficiency and the optimized volume of the nuclear power plant can provide reference for the research on the miniaturization design of the nuclear power plant. (authors)