Experimental study of a bilayer ceramic wick for the evaporator of a two-phase heat transfer device

Abstract

In order to enhance the thermal performance of two-phase fluid loop devices, the purpose of this study is to investigate the benefit of using a bilayer wick in a capillary evaporator.In a homogenous wick, the porous structure characteristics present an intrinsic competition between increasing the capillary forces and reducing the pressure drop.Our investigation focuses on studying heat and mass transfer in uniform and bilayer ceramic wicks with the same porosity. The findings highlight the interest of a bilayer ceramic wick with a pore diameter gradient. This configuration exhibits heightened capillary pumping without compromising liquid pressure drop, leading to improved thermal performance in the evaporator.Our results demonstrate that opting for a bilayer ceramic with a pore diameter gradient can save up to 25 °C at the casing temperature and reach up to 1430 W/m²K−1 as heat transfer coefficient for a 70 W heat load value.