Mechanical Characteristics Analysis of Stacked Magnet of Rare Earth Barium Copper Oxide Closed-Loop Superconducting Gourd-Shaped Loop

doi:10.12096/j.2096-4528.pgt.24126

Abstract

Abstract:

Objectives High-field superconducting magnets have great application value in many fields. Due to the immature welding technology, the second-generation high-temperature superconducting magnets cannot achieve persistent current mode operation. A rare earth barium copper oxide (REBCO) closed-loop superconducting gourd-shaped loop stacked magnet can achieve unimpeded closed-loop operation. It has been verified that it has the functions of flux density amplification and flux accumulation, and has the potential to achieve high magnetic field output. Therefore, it is crucial to study whether this magnet can maintain stability under high current and high magnetic field conditions. Methods A three-dimensional finite element model of this REBCO closed-loop superconducting gourd-shaped loop stacked magnet was established to analyze its electromagnetic response and stress-strain distribution under the field cold excitation method. Results The electromagnetic force per unit volume of the stacked magnet decreases gradually from the inner diameter to the outer diameter of the circular loop, with higher values at both ends and lower values in the middle, it presented a “U” shaped distribution. Additionally, the areas with significant stress are located at the connecting bridge and the junction between the loop and the bridge, making these regions prone to deformation and potential quench risks. Conclusions The analysis of the distribution characteristics of stress and strain of the magnet has a reference significance for improving the geometric shape of the gourd-shaped double-hole closed-loop superconducting sheet and the structure of the stacked magnet, and is of great significance to the safe operation of the magnet.

Key words: nuclear fusion, high temperature superconducting magnet, superconducting energy storage, rare earth barium copper oxide (REBCO), stacked magnets

CLC Number:

TK 01

Ting WANG, Yinshun WANG, Lining GUO, Yuyan BIAN, Zhanying LIAN, Leyi LI, Chengpeng MAO. Mechanical Characteristics Analysis of Stacked Magnet of Rare Earth Barium Copper Oxide Closed-Loop Superconducting Gourd-Shaped Loop[J]. Power Generation Technology, 2024, 45(6): 1039-1047.

Figures/Tables 13

Fig.1 Schematic view of REBCO superconducting gourd-shaped loop

Tab. 1 Main parameters of REBCO closed-loop superconducting gourd-shaped loop stack magnet

参数	数值
大圆内半径r₁/mm	6
大圆外半径r₂/mm	9
小圆内半径r₃/mm	3
小圆外半径r₄/mm	6
狭缝宽w₁/mm	0.1
连接桥宽w₂/mm	4
连接桥长l/mm	3
环片厚度d/mm	0.1
磁体层数	10

Fig. 2 Schematic diagram of REBCO closed-loop superconducting gourd-shaped loop stack magnets

Fig. 3 Schematic diagram of mesh division of REBCO closed-loop superconducting gourd-shaped loop stack magnet

Fig. 4 Excitation current timing diagram under field cooling method

Fig. 5 Schematic diagram of magnetic flux amplification of REBCO closed-loop superconducting gourd-shaped loop stack magnet under field cooling method

Fig. 6 Current density distribution cloud diagram of gourd-shaped stacked magnets after excitation

Fig. 7 Magnetic field distribution cloud diagram of gourd-shaped stacked magnets after excitation

Fig. 8 Schematic diagram of solving unit volume electromagnetic force in cylindrical coordinates

Fig. 9 Cloud diagram of the unit volume electromagnetic force distribution along the radial direction of the gourd-shaped stacked magnet after excitation

Fig. 10 The maximum unit volume electromagnetic force of each layer

Fig. 11 Normal stress and shear stress distribution cloud diagram of gourd-shaped stacked magnets

Fig. 12 Displacement variation diagram of gourd-shaped stacked magnets

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