Research On Thermal Hydraulic Performance Of The First Wall And Pebbles Bed In Blanket Of Nuclear Fusion Reactor

For ITER, the heat transfer parameters of test blanket module are very important. Scientists of every country are setting about the numerical simulation of it. Many simulation results have been generated report and applied to manufacture the products. There’s also doubt about whether the results can be trusted. The investigations of this paper are based on this point.In this paper, a test rig has been built, based on the inner pipe model, for the first wall(FW). Design data acquisition system, heating system and gas flow control system. Finished comprehensive experiments with different Re number, volumetric section and heat flow rate. Create 3D model, with the 25 mm pipeline, to compare different results of empirical data and simulation. In order to find out the heat transfer rules in the blanket, a testing device has been built to measure the equivalent temperature conductivity of granule beds. A Li2TiO3 pebble bed is made up of granules in the diameter vary from 1-1.5 mm, is placed in a 20 mm width column space. Explore the convective thermal conduction, under different conditions of temperature, filling rate and gas.The result indicated that heat flux has little impact on convective heat transfer effective. But high levels of heat flux would have a more precisely measuring result, especially under a large Reynolds number. Pipes with different volumetric sections provide various heat transfer performance. Pipeline with 25×25mm cross section works best, which was particularly apparent after the Re higher than 70000. The result also shows that airfoil tube, in the pipe bend, would strengthen local and overall heat transfer ability. There is a little increase for flow resistance of pipeline, compared to the general bend. Both pipe surface temperature and inner pressure drop, in the experiment and simulation, have the same trend. The results error is less than 9%, which proved the availability of the simulation method. Pebble beds’ experiment goes under vary fill rate, and mean temperature. The 88% fill rate result shows that the equivalent temperature conductivity is in basically proportional to mean temperature. While the heat conduction close to barrier face is changed little, and its average is 254W/m2 K. Different filling rate would change the equivalent temperature conductivity(ETC) obviously, which indicated that pebbles beds filling with vibration is the most effective way to increase the heat conduction performance. Influence can filling-gas exert over ETC, mainly based on the thermal conductivity itself.