Development of a High-Efficiency Conduction Cooling Technology for SMES Coils

• Published in: IEEE transactions on applied superconductivity Vol. 23; no. 3; p. 5602804
• Main Authors: Nagaya, S., Hirano, N., Naruse, M., Watanabe, T., Tamada, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Circulation; Coils; Conduction cooling; COOLING; Cooling systems; COPPER OXIDE; Direct energy conversion and energy accumulation; ELECTRIC COILS; Electric wire; Electrical engineering. Electrical power engineering; Electrical power engineering; Electromagnets; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Energy accumulation; Exact sciences and technology; Heat; Heating; high voltage; Insulation; INSULATION (ELECTRICAL); pancake coil; Power electronics, power supplies; SMES (superconducting magnet energy storage system); Studies; SUPERCONDUCTIVITY; SUPERCONDUCTORS; Temperature distribution; Temperature measurement; Various equipment and components; WIRE; YBCO superconductors; YTTRIUM OXIDE; Thermal management (packaging); High density; pancake coil; Heat flow; Conduction cooling; Electrical insulation; High temperature; Coatings; Heat flux; High temperature superconductor; Superconducting magnet energy storage; Electrical characteristic; Cooling; Energy density; Power electronics; Superconducting wires; Superconducting coils; Coated material; High power; High voltage; High energy; High efficiency; Cooling system; Large scale; Critical temperature; Comparative study; SMES (superconducting magnet energy storage system); Energy storage
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2012.2235751

YBCO(YBa 2 Cu 3 O 7 ) wires have superior characteristics such as high energy densities, thus allowing the fabrication of large-scale, high power-output superconducting equipment applications. A high voltage is desired to achieve a large power output from a superconducting coil, and is realized by improving the insulating properties of the coil with the introduction of solid insulation. However, because high temperature superconducting wires have high critical temperatures and thermal tolerance compared to metal-based superconducting wires, the benefits offered allow the insulated superconducting coil to be directly cryocooled. In a helium circulation cryocooling system, the aluminum-fabricated transmission heat shields are coated around the surface of the coils to cryocool equally, and are embedded into the transmission heat shields with the conducting pipe allowing helium gas to circulate. We manufactured a conduction cooled model coil of 600 mm class diameter, and have verified the ability to realize a cooling of more than 3 W/m 2 for coil surface heat flux at an operating temperature of 20 K using the demonstration cooling system. In addition, we have also evaluated the electric insulation performance, which is in contradiction to the cooling performance. The conduction-cooled YBCO coil withstood up to DC 13 kV voltages at 20 K.