| The goal of International Thermonuclear Experimental Reactor（ITER）is to developa controllable Tokamak device, which is self-sustaining combustion, for scientificexploring and studying fusion energy peacefully and safely through internationalcooperation. As an important part of ITER Feeder System, Cryostat Feed-Through（CFT）is one of the key parts of fusion device. So, it is necessary to study CFT and itskey parts.In this paper, the research status of CFT and major domestic and foreign tokamakthermal shields is extensively investigated. Design criteria and material selectionprinciples for CFT are established referring to the overall design of ITER-relateddocuments. According to CFT thermal shield characteristics of complex structure andmulti-field effect, thermal, electromagnetic and coupling analysis and experimentalresearches are carried out. The main research work and achievements accomplished areas follows:（1）Regarding to the design of CFT thermal shield, a design method consideringmulti-field coupling analysis, manufacturing and experiment is established bycomprehensively using of electromagnetic theory, thermodynamics, coupled analysistheory, finite element theory, computer-aided engineering, mechanical design and otherdisciplines of knowledge. Furthermore, the thermal analysis of Thermal shield isverified through thermal experiment.（2）The parameters of CFT thermal shield are designed and analyzed in detail bycomprehensively using of formula calculation and finite element simulation, andestablished ultimately through comparative analysis of each design scheme. In addtion,welding types are filtered and the welding program of cooling pipes is determined bywelding experiments.（3）For the electromagnetic analysis of CFT thermal shield, a combined analysismethod of analytical method and FEM is proposed and the electromagnetic analysisdata of magnetic field and eddy current distribution are obtained. The feasibility ofcalculation method and the correctness of calculated results are validated by comparingthe calculated results of two methods.（4）With regard to the thermal analysis of CFT thermal shield, heat source and heattransfer mode of CFT thermal shield are expounded in detail. Then, heat flux density of radiation and heat transfer coefficient of convection are calculated. Finally, theelectromagnetic-thermal partial coupling analysis of CFT thermal shield is finished bycrediting the joule heat from electromagnetic analysis as heat source in thermal analysis.（5）By introducing multi-field coupling analysis theory into the analysis of CFTthermal shield, a multi-field coupling analysis method for CFT thermal shield isdeveloped. On the basis of electromagnetic and electromagnetic partial couplinganalysis, the analysis of electromagnetic-thermal-structural global coupling for CFTthermal shield is completed by putting electromagnetic force and temperature loads intostructural analysis.（6）The multi-layer insulation of thermal shield has been studied deeply and the heatloss of heat radiant, heat conduction and heat convection is analyzed and calculated.Detailed comparative experiments of thermal shield for sliver plating process andsilvered surface emissivity at low temperature are conducted, which can providedetailed and reliable experimental data and referential program for thermal shieldsurface treatment of future tokamak device. |
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