Доступ предоставлен для: Guest
International Symposium on Heat and Mass Transfer in Refrigeration and Cryogenics
September, 1-5, 1986, Dubrovnik, Yugoslavia

DOI: 10.1615/ICHMT.1986.IntSympHMTinRefCryo


ISBN Print: 978-3-54017-957-3

Thermal Stability of a Superconductor Cooled by a Turbulent Flow of Supercritical Helium

pages 641-653
DOI: 10.1615/ICHMT.1986.IntSympHMTinRefCryo.450
Get accessGet access

Краткое описание

The thermal stability of large superconductors as used in magnets for fusion research depends strongly on dynamic effects on the heat transport to the cooling medium. For large magnets in general supercritical helium is used for cooling. It flows through long narrow channels adjacent to the superconductor material. If a thermal transient occurs locally in the cable the heat transport through the copper/superconductor matrix itself and the transport to the turbulent helium flow should stabilize the conductor to prevent a large local energy release.
The stability of superconducting magnets has extensively been studied by Stekly [1] , Maddock [2] , Keilin [3] , Iwasa [4] and Cornelissen and Hoogendoorn [5] using static criteria. The latter authors also studied dynamic criteria [6] and in a further paper [7] considered the propagation velocity of a thermal disturbance during a transient.
The use of static criteria is insufficient. A full study of thermal stability requires a dynamic simulation in which both transient heat conduction in the copper /superconductor matrix and transient thermal and flow effects in the helium are considered. In this paper we will shortly discuss the full model and then give particular attention to the transient effects in the helium flow. The model has been applied to study the stability of a specific conductor as used in the superconductor test facility SULTAN. In cooperation with several European countries a high current superconductor is tested in a high magnetic field. The conductor is cooled by a turbulent flow of supercritical helium.

Портал Begell Электронная Бибилиотека e-Книги Журналы Справочники и Сборники статей Коллекции Цены и условия подписки Begell House Контакты Language English 中文 Русский Português German French Spain