Heat Transfer Performance of a Water Impinging Jet Flow in a Metal Particle Bed

Abstract

This study evaluates convective and boiling heat transfer characteristics of a water impinging jet flow in porous media in order to remove the heat flux of 10 MW/m2 imposed to fusion divertors. The metal porous media with complicated microchannels have large heat transfer surface due to fin effect and superior mixing effect of fluid, which enhances not only the convective heat transfer but also the boiling heat transfer by improving the evaporation rate of the cooling liquid. In a proposed heat removal device called EVAPORON-3-Type3, the cooling water is supplied as an impinging jet flow into the porous medium, which is a two-layered copper particle bed, and the generated vapor is discharged through high porosity gaps on the heat transfer surface. As a result, the convective heat transfer coefficient is improved by 1.6 times compared with that of an impinging jet flow without the copper particle bed. In the boiling heat transfer regime, the critical heat flux is increased by 1.5 times and the heat flux of 8.4 MW/m2 is achieved under low velocity and highly subcooled conditions though it’s not maximum.