The Design And Integration Technology Research Of CFETR Central Solenoid Superconducting Model Coil

China fusion engineering reactor experiment(CFETR)is to design and build an engineering experiment fusion reactor before the construction of fusion demonstration reactor,base on multiple tokamak design,construction,and operation experience in China and on the basis of absorbing ITER technology,and it will provide the technical foundation for the construction of fusion demonstration reactor and the ultimate commercial fusion reactor.The central solenoid(CS)coil is one of the important parts of the tokamak device.The main function is to induce the plasma current and to form the plasma with the PF coil.CFETR central solenoid coil has a peak field of 12T with the operating current of 47.65 kA,so Nb3Sn superconducting conductor must be used.At present,China has very little experience in the development of large superconducting magnets with Nb3Sn superconducting conductor,which is very unfavorable to the construction of our fusion engineering experimental reactor(CFETR).The design and manufacture of CFETR center solenoid(CS)model coil with the Nb3Sn superconducting conductor has a great significance for exploring the engineering design,mastering the manufacturing process and winding method of large superconducting magnets.In this paper,the engineering structure design,optimization design and finite element analysis of CS model coil are carried out by using many scientific theories such as mechanical design,computer-aided engineering,mechanics,optimization design and finite element simulation.Based on the theories of electromagnetics,heat transfer and optimal design of mechanical structure,the large-scale central solenoid(CS)model coil with Nb3Sn superconducting conductor was designed for the first time in China,and a reasonable structure was provided for the manufacture of the final CS model coil.According to the physical design objective and electromagnetic design result of CFETR CS model coil,the detailed structure design of coil winding is performed.In order to satisfy the design objective and reduce the cost of coil manufacturing,the coil was designed as a mixed magnet coil,Nb3Sn conductor is used in the high field area on the inside and NbTi conductor is used in the low field area on the outside.CS model coil consist of 5 coils,Nb3Sn inner coil and outer coil,Upper NbTi coil,middle NbTi coil and lower NbTi coil.The distribution of coil leads,feedthrough and joints are designed,there are 6 joints between each coils and 4 current inlet and outlet joints,with a total of 10 joints.Based on the AN SYS optimization design module,the preload beam of the preload structure is optimized,and the optimal dimension of the preload beam is M140mm.Multiple physical field coupling analysis method of superconducting magnet complex 3D model is established based on ANSYS,and this method has been applied for stress analysis and strength evaluation of CS model coil preload structure,leads,feedthrough,reinforcing plate for leads,and support of leads and feedthroughs under three kinds of conditions.The design of the structure are all meet the design requirements.In addition,the layout design of cooling He pipes and its support of CS model coil are carried out.The detailed CS model coil assembly and integration procedure is developed,and some solutions are given for the key technical difficulties.The problem of insufficient lifting capacity of CS model coil test hall is solved,and the problem of small clearance for coil assembly and position,and joint docking in the assembly process are solved,and some difficult problems such as the loading of large preload fore in a small space for the preload strucrue are also solved.