An evaluation of the inlet flow reduction for a cable in conduit conductor by rapid heating

摘要

The flow reduction of forced flow superconductingcoil with a cable in conduit (CIC) conductor has been studied forAC losses due to pulsed operation. In this paper, the flowreduction by rapid heating is described for forced flowsuperconducting coil with a CIC conductor.The phenomenon of flow reduction of the forced flow coil hasbeen applied for coil quench detection and has been developed byJapan Atomic Energy Research Institute (JAERI). It is named the"fluid method" and essential technology for quench detection oflarge-scale forced flow superconducting coil as fusion magnetsand superconducting magnetic energy storage (SMES) coil. In thefluid method, the inlet flow reduction is caused by Joule heatingon the normal zone of superconducting coil. The fluid method hasno electric noise in its detection. This is an advantage for pulsedoperation in comparison with other electrical quench detection systems.On the other hand, there are no quantitative considerationsbetween the inlet flow reduction and Joule heating of the coilinside in previous studies. The flow reduction for the quenchdetection has been determined by the operation experience offorced flow superconducting coil. The purpose of this paper s anestimation of the relation between the inlet flow reduction andJoule heating at coil quench.First, the inlet flow reduction was obtained by experiment inwhich the sample has an inductive heater for the quench emulation.Second, the evaluation model was proposed and its model showedgood agreement between the inlet flow reduction and heatgeneration of the oil inside by rapid heating as coil quench. 2000Elsevier Science Ltd. All rights reserved.