29th Symposium on Fusion Technology (SOFT 2016)

P1.088 Towards a multi-physic platform for fusion magnet design – Application to DEMO TF coil

5 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 88

Poster E. Magnets and Power Supplies P1 Poster session

Speaker

Quentin Le Coz (IRFM)

Description

In the framework of the EUROfusion DEMO project, studies are conducted in several European institutions for designing the tokamak magnet systems. In order to generate the high magnetic fields required for the plasma confinement and control, the reactor should be equipped with superconducting magnets, the reference design being based on Cable-In-Conduit Conductors cooled at cryogenic temperatures by forced circulation of supercritical helium. In order to propose a TF Winding Pack (WP) design compatible with DEMO requirements, CEA has developed several tools addressing the different areas related to magnet dimensioning. An accurate calculation of magnetic field along the conductor is provided by the TRAPS code, and conductor design is performed using an integrated macroscopic home design code based on simplified models accounting for superconducting properties, mechanics and thermal. This multi-physic tool gives a realistic but not assessed design. Indeed it is based on an assumed operating temperature that must be validated with an elaborated code, since it is linked with temperature margin design criterion (1.5 K). A dedicated modelling tool was developed by coupling the THEA code for 1D thermo-hydraulics in cables and the Cast3M code for 2D transverse thermal diffusion in a limited number of coil cross sections enhancing the accuracy of the outputs as being a quasi-3D approach. This tool allows a better assessment of the flux exchange between WP and casing, and the modeling of inter-turn / inter-pancake thermal coupling. The coupling methodology is described, as well as its validation on an academic case (simulation of a heat exchanger) and its application to CEA proposal for DEMO TF coil. A calculation was performed on the TF coil (CEA configuration) in a burn (steady state) scenario, also considering cooling channels in the casing, and finally showing a safe temperature margin i.e. compliant with 1.5 K criterion.