Thermal-hydraulics
in
super-conducting cables and magnets
Introduction ·
Thermal-hydraulics constitutes an important subject in the
field of applied superconductivity and cryogenics, and a strongly
inter-disciplinary topic of current research, with particular reference to
fusion magnets applications (e.g., the International Thermonuclear
Experimental Reactor --ITER). ·
The tasks to be solved by the modeler concern the
refrigeration of super-conductors and include the study of the evolution of
thermal-hydraulic transients in complex systems with nonlinearly coupled
solids and fluids. The solution of these issues is essential for the proper
design and operation of very expensive components. ·
Timescales to be considered range from the very short,
stability timescale, to intermediate, quench timescales, to long-timescale
phenomena, e.g. the cool-down of an entire magnet. |
Typical ITER cable-in-conduit conductor |
|
The ITER Central Solenoid Model Coil Testing Group
on April 19th, 2000, just after the successful completion of the DC
charging tests at JAEA Naka, Japan. Participants to the 12th ITER Toroidal Field Model Coil Test and Analysis Meeting (Cadarache, France, October 2000). |
Major
achievements ·
Development of a 1-D 2-fluid model (ŕMITHRANDIR code) for the analysis of
thermal-hydraulic transients in a single dual-channel cable-in-conduit
conductor cooled by helium I or II, its validation against data from QUELL,
FSJS, and other experiments, and its application to the ITER design ·
Development and validation of quasi 3-D models for coupled
conductors within a coil (ŕ M&M code) and for localized phenomena on the conductor cross
section (ŕ M3 code). ·
Application of the codes to the analysis of different
transients (e.g., current sharing temperature measurement and DC performance
assessment, AC losses measurement, stability and quench tests, hydraulic
characterization), after participation to all the experimental campaigns on
the ITER Model and Insert Coils. ·
Development and validation of the Cryogenic Circuit,
Conductor and Coil -- 4C
code against data from different magnet systems,
spanning from fast discharge to week-long cool-down. The extensive
application of the code to the ITER magnet system is presently ongoing. ·
Development of the thermal-hydraulic module of the THELMA code, for the integrated
thermal-hydraulic electromagnetic simulation of ITER cable-in-conduit
conductors. Validation and application of the resulting tool to the analysis
of transients where the effects of current unbalance/redistribution are
relevant ·
CFD analysis of basic transverse transport phenomena in
ITER CICC (using the FLUENT code)
as well as of heat exchangers for the high temperature superconducting
current leads (using the STAR CCM+
code) |
|
Past and
present collaborations ·
In Italy: ENEA
Frascati, Politecnico di Milano, Universita’ degli Studi di Bologna,
Universita’ degli Studi di Udine. ·
Abroad: CEA
Cadarache (France), CRPP Villigen (Switzerland), F4E Barcelona (Spain), ITER
IO Cadarache (France), USIPO Oak Ridge (USA), JAEA Naka (Japan), KIT Karlsruhe (Germany), NFRI Daejeon
(Korea), PSFC – MIT Cambridge (USA). |
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