Speaker
Silvia Garitta
(Dipartimento di Energia)
Description
In the framework of the work package "Divertor" of the EUROfusion action, a research campaign has been jointly carried out for the subproject "Cassette design and integration" by ENEA and University of Palermo to investigate the thermal-hydraulic performance of the DEMO divertor cassette cooling system. A comparative evaluation study has been performed considering three different options of cooling circuit layout for the divertor Plasma Facing Components (PFCs). The potential improvement in the thermal-hydraulic performance of the cooling system to be achieved by modifying the coolant circuit layouts has been also assessed and discussed in terms of optimization strategy.
The research activity has been carried out following a theoretical-computational approach based on the finite volume method and adopting a qualified Computational Fuid-Dynamic (CFD) code.
CFD analyses have been carried out for the PFCs cooling circuit lay-out options under nominal steady state conditions and their thermal-hydraulic performances have been assessed in terms of overall coolant thermal rise, coolant total pressure drop, flow velocity and CHF margin distributions along the vertical target Plasma Facing Unit (PFU) channels, to check whether they comply with the corresponding limits.
Results obtained have clearly predicted very modest coolant thermal rises (lower than 10 °C) for all the PFCs cooling options investigated as well as a sufficient margin against CHF onset (higher than 1.4) along all their PFU channels. Conversely, estimated total pressure drops have resulted higher than the limit of 1.4 MPa for all the PFCs cooling options investigated, especially in case of option 2.
Therefore, an optimisation study has been carried out to minimize the cooling options total pressure drop by properly changing their geometric configuration. In particular, the potential effect of increasing PFC inlet/outlet manifold diameter has been investigated with encouraging results for all the three options. Results obtained are reported and critically discussed.
Co-authors
Eugenio Vallone
(Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici, University of Palermo, Palermo, Italy)
Giuseppe Mazzone
(ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (RM), Italy)
Jeong-Ha You
(Max Planck Institute of Plasma Physics (E2M), Boltzmann Str.2, 85748 Garching, Germany)
Pietro Alessandro Di Maio
(Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici, University of Palermo, Palermo, Italy)
Silvia Garitta
(Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici, University of Palermo, Palermo, Italy)