Heat transfer analysis of thermoelectric driven swirling flow

Nuclear fusion;liquid metal;lithium;thermoelectric;Magnetohydrodynamics (MHD);plasma facing component;divertor

Xu, Wenyu ; Ruzic ; David N.

关键词: Nuclear fusion;    liquid metal;    lithium;    thermoelectric;    Magnetohydrodynamics (MHD);    plasma facing component;    divertor;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/42189/Wenyu_Xu.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

As fusion experimental devices progress it has become a challenging problem to remove the intensive heat from the divertor region. The solid plasma facing materials (PFM) suffer from the sputtering and thermal stress. An alternative way is to utilize liquid metal especially the liquid lithium as the divertor material. An experiment on CDX-U found that a shallow pool of liquid lithium could bear 60MW/m2 heat flux without significant evaporation. A swirling flow pattern was observed during the experiment which was firstly believed to be Marangoni effect. To reveal the truth of this flow the Solid/Liquid Lithium Divertor Experiment (SLiDE) was constructed at University of Illinois, Center for Plasma-Material Interactions. SLiDE has similar experimental conditions as CDX-U and in recent experiments thermoelectric magnetohydrodynamics (TEMHD) was proved to be the dominant driven force of this kind of swirling flow. Its fluid properties were fully investigated later and a group of equations have been developed to describe the velocity field.Following the previous work this thesis focuses on the heat transfer analysis of the TEMHD driven swirling flow. An infrared (IR) camera system was installed and calibrated to monitor the surface temperature change under different experimental conditions especially the highly focused heat flux. In addition the 3D dimensionless heat transfer equation is analyzed and simplified for experiment related parameters. A relevant 3D convection heat transfer model was built to calculate the detailed temperature distribution and the results were compared to the IR camera results. Good agreement was achieved under some conditions while some difference generated when the height of the liquid lithium was changed. The changing velocity field in the boundary layer was raised as a possible reason.