Predictive 1-D thermal-hydraulic analysis of the prototype HTS current leads for the ITER correction coils. (December 2016)

• Record Type: Journal Article
• Authors: Heller, R.; Bauer, P.; Savoldi, L.; Zanino, R.; Zappatore, A.
• Is Part Of: Cryogenics. Volume 80:Part 3(2016)
• Page Start: 325
• Page End: 332
• Publication Date: 2016-12
• Subjects: ITER -- High temperature superconductors -- Current leads -- Meander-flow type heat exchanger -- Numerical modeling; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2016.05.002
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: 1-D code CURLEAD now equipped with correlations for friction and HTC from CFD. CURLEAD simulations performed without knowledge of ITER CC CLs test results. CURLEAD shows very good predictive capability of steady state HTS CL performance. Qualitative agreement CURLEAD-experiment in pulsed scenario. Abstract: We present an analysis of the prototype high-temperature superconducting (HTS) current leads (CLs) for the ITER correction coils, which will operate at 10 kA. A copper heat exchanger (HX) of the meander-flow type is included in the CL design and covers the temperature range between room temperature and 65 K, whereas the HTS module, where Bi-2223 stacked tapes are positioned on the outer surface of a stainless steel hollow cylindrical support, covers the temperature range between 65 K and 4.5 K. The HX is cooled by gaseous helium entering at 50 K, whereas the HTS module is cooled by conduction from the cold end of the CL. We use the CURLEAD code, developed some years ago and now supplemented by a new set of correlations for the helium friction factor and heat transfer coefficient in the HX, recently derived using Computational Fluid Dynamics. Our analysis is aimed first of all at a "blind" design-like prediction of the CL performance, for both steady state and pulsed operation. In particular, the helium mass flow rate needed to guarantee the target temperature at the HX–HTS interface, the temperature profile, and the pressure drop across the HX will be computed. The predictive capabilities of the CURLEAD model are then assessed by comparison of the simulation results with experimental data obtained in the test of the prototype correction coil CLs at ASIPP, whose results were considered only after the simulations were performed .