Designing and Simulating an additive manufacturable liquid metal heat pipe for future fusion application

Abstract

The feasibility of a radiatively cooled 3D-printable liquid metal heat pipe (HP) design is assessed. Using the design flexibility offered by 3D-printing, the design of the wick and geometry of the HP were optimised to meet the requirement of 20 $\mathrm{MW}/m^2$ heat load for a HP placed in a 1.5 T magnetic field. COMSOL was used to assess the operational limits of the HP, the thermal stresses in the wall, the thermally radiated power, and various materials for the HP. The main parameters are the diameter and spacing of the screen wires and the emissivity, 200 $\mu m$, 200 $\mu m$ and 0.86 respectively. Molybdenum was chosen as the wall material and lithium as the working fluid. The design was made in Siemens NX and then exported to COMSOL. From simulations it was concluded that a molybdenum HP with the final design was capable of handling a steady state heat load of 20 $\mathrm{MW}/m^2$.