Experimental investigation of the flowing lithium limiter. Part 1. The spreading characteristics of lithium on solid substrate without an external magnetic field

Abstract

In the present study, the Magneto-Thermo-Hydrodynamic-Lithium (MaTH-Li) loop is established to carry out fundamental studies on the liquid metal (LM) components. In the first step of our experiments on lithium LM components, the LM limiter is designed according to suggestions from Hu et al. (Nucl. Fusion, 2016, 56, 046,011) to check the spreading characteristics of lithium flow on a plate with an area of 300×298 mm2. By changing the flow rate of lithium at a fixed tilt angle of 60◦, the spreading characteristics of lithium flow on the limiter are captured by a camera. Our experimental results reveal that the liquid lithium can cover nearly the whole surface of the limiter, with a coverage ratio of 97.32%, which is the highest one reported. Moreover, the free surface lithium flow can keep for a range of flow rates which proves robust to the present LM limiter. However, due to the oxidation of lithium on the surface of the limiter after 20 days, the coverage ratio of flowing lithium on the limiter surface reduces to 84%, which is similar to the results of FLiLi in the EAST device. The lithium splashing with an average lithium droplet size of 0.175 mm appears in some typical flow conditions without the influence of an external magnetic field, which needs further improvements in the design of the LM limiter.