Research And Optimization Design Of Turbo-generator For Small Lead-bismuth Fast Reactor

With the determination of China’s dual carbon target,nuclear power will gradually replace coal power as a new base charge power source,and develop in collaboration with other clean energy sources to effectively promote the realization of the dual carbon target.Lead-based fast reactor as the fourth generation reactor,has higher safety and economy,and has a broader space for development.At present,China’s first zero-power lead-based fast reactor has achieved its first criticality.In order to achieve the construction target of small lead-based demonstration reactor in 2025,the research on small lead-based fast reactor generator set is more and more urgent.Lead-based fast reactor put forward new design requirements for turbo-generators,this paper mainly studies turbo-generators suitable for small lead-based fast reactor.According to the characteristics of lead-based fast reactor,the electromagnetic design,performance optimization and verification analysis of turbo-generators are completed.In this paper,the research direction and application scenario of lead-based fast reactor are analyzed.According to the working characteristics and performance requirements of lead-based fast reactor,a turbo-generator design scheme suitable for small lead-based fast reactor is proposed.The basic structure and electromagnetic calculation method of small lead-based fast reactor turbo-generator are summarized and analyzed,and the main performance parameters and losses of the turbo-generator are calculated and the relevant theory is analyzed.Secondly,the rated parameters and design requirements of the generator are determined.According to the calculation method and electromagnetic design process,the structural parameters of the generator are calculated.Furthermore,magnetic circuit calculation method and finite element method were used to check and improve the electromagnetic parameters of the generator during operation,and the efficiency,short-circuit ratio,magnetic density distribution,induced electromotive force waveform and other parameters were obtained by simulation calculation.The influence of main steam parameter fluctuation on generator performance is analyzed by simulation.Thirdly,the optimization parameters of six generators were analyzed and determined,and the neural network replacement model was established based on the sampling data.The multi-objective genetic algorithm was used to optimize the generator efficiency and power density globally,and the finite element method was used to verify the correctness of the solution results.Finally,the temperature rise of the generator is simulated and verified.The simulation results show that the temperature distribution of the generator air cooling is reasonable and the temperature rise meets the design requirements.According to the characteristics of high power density of lead and lead-based fast reactor turbo-generator and the characteristics of self-circulation of coolant,the stator winding cooling system designed has simple structure and high operation efficiency.In extreme cases,it can protect the insulation of the motor,greatly reduce the stator winding temperature,and further reduce the copper loss of the armature.