Coupling Analysis Of Electromagnetic Structure Of Tokamak Vacuum Vessel Under Complex Electromagnetic Field

The vacuum vessel is the core component of the fusion reactor,providing restraint barriers for the reactor,resisting accidents that may occur,ensuring a high vacuum environment,and providing support to internal components.During the discharge experiment,the vacuum vessel will face various electromagnetic loads.Plasma rupture,vertical displacement events and thermal quenching are three typical operating conditions.It is very important to find a reliable vacuum vessel electromagnetic structure coupling analysis method.During plasma rupture(MD),the EAST plasma current center position remains constant relative to the vacuum vessel,and the plasma current decays exponentially with a 1 MA initial current with a time constant of 3 ms.The violent current changes cause the vacuum vessel to have a strong eddy current effect and to withstand large electromagnetic loads.Based on the ANSYS finite element analysis software,this paper verifies the coupling analysis methods of various electromagnetic structures based on the electromagnetic load of the vacuum vessel under plasma rupture conditions.According to the results of the coupling analysis,the structure of the EAST vacuum vessel is optimized.The main work of this paper is:1)This paper conducts a detailed survey of the current state of energy development in the world and the significance of developing controlled nuclear fusion for future humans.The main design parameters of the vacuum vessels of the main tokamak devices at home and abroad are summarized.2)Summarize the relevant theoretical knowledge of the electromagnetic-structure coupling analysis of the-vacuum vessel,including the required finite element basic knowledge,the basic theory of electromagnetics and structural mechanics,and the load transfer method of coupled analysis.The formula for electromagnetic analysis and structural analysis of the vacuum vessel is deduced in detail.3)Perform a confirmatory analysis experiment on a variety of electromagnetic structure coupling analysis methods by establishing a Benchmark model that simulates the loading situation of the vacuum vessel in the MD event.Using copper plate instead of vacuum vessel model,and using excitation 1=800[EXP(-500*T)-EXP(-6000*T)](A)to simulate plasma current decay function.Electromagnetic-structural coupling analysis was performed on the Benchmark model using Direct-Coupled method,MFS Single Code method and Maxwell coupling method.The electromagnetic force,eddy current and magnetic field distribution of the copper plate are calculated by comparing the coupling methods,and the structural displacement curve is compared with the experimentally measured displacement results.Verify the accuracy of these electromagnetic structure analysis methods,and conclude that the analysis results using Maxwell coupling method are the best.4)Maxwell coupling analysis method is used to couple the EAST vacuum vessel during MD operation,obtain the electromagnetic load data on each PS segment of the vacuum vessel,and optimize the structure of the vacuum vessel rib based on the calculated data;The vacuum vessel model of different thickness ribs is used to analyze the electromagnetic structure coupling.The influence of the thickness of the ribs on the electromagnetic load of the vacuum vessel is studied,which provides a reference for the structural optimization of the vacuum vessel.