Design Optimization Of Nuclear Island Cold Chain System In Nuclear Power Plants

The nuclear island cold chain system is an important system that ensures the normal operation and safety of nuclear power plants.It is composed of the seawater system(essential service water system),equipment cooling water system,and numerous sub-systems.If there is a lack of overall consideration in the design,the cooling system could become bulky and inefficient.By applying optimization design methods to explore the relationship between design parameters and system performance goals while ensuring the safe operation of the system,it is possible to find ways to reduce system weight,volume,and costs,which can provide theoretical references and bases for optimizing the nuclear island cold chain system.Therefore,based on the above research background,this article establishes a mathematical model for the overall nuclear island cold chain system,develops corresponding design evaluation programs,and uses suitable optimization algorithms to conduct optimization design research on the nuclear island cold chain system of nuclear power plants.This study first developed a design model,verification model,and evaluation model program for the equipment within the nuclear island cold chain system using the C# language.Additionally,a valve design selection program was developed to address the issue of inconvenient flow regulation using orifice plates in the existing system.The reliability of the established programs was also validated.Furthermore,based on the model programs of each piece of equipment and their operating conditions,an overall mathematical model program for the nuclear island cold chain system was established.Next,commonly used optimization algorithms in nuclear power plants were analyzed,and the new hybrid genetic algorithm was selected for the optimization design research of the nuclear island cold chain system based on its characteristics of multi-variable,non-linear,and multi-peak optimization problems.The applicability of the selected algorithm was also validated.Typical equipment within the nuclear island cold chain system was then subjected to single-objective and multi-objective optimization design research.The plate heat exchanger in the spent fuel pool cooling system was chosen as the typical equipment.Based on the established model and the selected optimization algorithm,the investment cost,cold side resistance,and hot side resistance of the system heat exchanger were selected as the optimization objectives for single-objective and multi-objective optimization design research.Lastly,single-objective and multi-objective optimization design research was conducted on the overall nuclear island cold chain system.Based on the established mathematical model and selected optimization algorithm program,the investment cost,weight,volume,and pump power of the entire system were selected as the optimization objectives for single-objective and multi-objective optimization design research.The optimal design direction for the nuclear island cold chain system was identified,and optimal parameter settings for the system were proposed.The optimal design results of the whole nuclear island cold chain system show that: In the summary of optimization schemes obtained,the minimum investment cost can reach 95% of the mother model,the minimum weight can reach 82% of the mother model,the minimum volume can reach 87% of the mother model,the minimum pump power can reach 63% of the mother model,and there are four objectives are better than the mother value of the design scheme,nuclear island cold chain system has a certain optimization space.