29th Symposium on Fusion Technology (SOFT 2016)

P2.164 Liquid metal heat and mass transfer coefficients in vertical ducts with flow channel inserts

6 Sep 2016, 14:20

1h 40m

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

Board: 164

Poster H. Fuel Cycle and Breeding Blankets P2 Poster session

Speaker

Daniel Suarez (Department of Physics)

Description

The conceptual design of the European Dual Coolant Lead Lithium (DCLL) breeding blanket is currently being developed in the frame of EUROfusion Project. To this aim, it is of utmost interest to estimate critical flow parameters such as: (1) pressure drop and heat transfer coefficient at both helium and lithium sides, and (2) tritium permeation ratio. Pressure drop in purely hydrodynamic flows (such as in the case of helium cooling channels) has been extensively studied, and the same occurs with purely hydrodynamic heat transfer coefficients. However, in the lead lithium side, magnetohydrodynamic (MHD) effects considerably modify the flow and, thus, new correlations for pressure drop and heat transfer coefficient must be obtained. There is a large background on the estimation of MHD pressure drop, mainly focused on fully developed isothermal flows. However, there is scarce information related with heat transfer coefficient under MHD flow conditions. Here, the front poloidal duct of the DCLL breeding blanket with flow channel inserts (FCI) and helium cooling channels at the first wall is studied assuming fully developed flow. A radially varying volumetric heating is considered. A parametric study is performed for Hartmann, Reynolds and Grashof numbers as well as for FCI electrical conductivity. It is not the aim of the present study to develop new correlations, but to provide the order of magnitude of both the pressure drop and the heat transfer coefficients for lead lithium under relevant DCLL flow conditions. As a second step, and considering tritium transport as a passive scalar, i.e. without disturbing lead lithium flow, tritium mass transfer coefficient is calculated in order to study the effect of the studied flow conditions on the tritium permeation ratio.