Numerical Simulation of Thermal Properties of a Cryocooler-Cooled Bi2223 Superconducting Pulsed Coil in AC Operation

Author

Miyazaki, H. ; Chigusa, S. ; Tanaka, I. ; Iwakuma, M. ; Funaki, K. ; Hayashi, H. ; Tomioka, A.

Author_Institution

Graduate Sch. of Inf. Sci & Electr. Eng.., Kyushu Univ.

Volume

16

Issue

2

fYear

2006

fDate

6/1/2006 12:00:00 AM

Firstpage

1749

Lastpage

1752

Abstract

We fabricated a cryocooler-cooled Bi2223 superconducting pulsed coil and experimentally studied the thermal runaway in dc or ac operation. We carried out numerical simulation of thermal properties of the coil in order to explain the thermal runaway of the coil. Firstly, we analyzed the total heat generation of flux-flow losses and ac losses inside the winding from the experimental results of the external field losses and the E-J characteristics for the Bi2223 strands. Secondly, we numerically simulated the thermal properties by using a 2-dimensional heat conduction equation with axial symmetry. The numerical simulation shows the relation between the initiation of thermal runaway and the temperature distribution with highly concentrated heat source in the winding. We have a semi-quantitative agreement between the numerical results and the experimental ones for the condition of the thermal runaway

Keywords

bismuth compounds; calcium compounds; heat conduction; heat losses; high-temperature superconductors; lead compounds; strontium compounds; superconducting coils; 2-dimensional heat conduction equation; Bi_2-xPb_xSr₂Ca₂Cu ₃O₁₀; ac losses; axial symmetry; cryocooler-cooled superconducting pulsed coil; flux-flow losses; numerical simulation; temperature distribution; thermal properties; total heat generation; Conductors; Cooling; Current measurement; Numerical simulation; Superconducting coils; Superconducting filaments and wires; Temperature distribution; Thermal conductivity; Thermal factors; Thermal stability; AC loss; cryocooler-cooled Bi2223 coil; thermal properties; thermal runaway;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2006.873266

Filename

1643200