Experimental Study on the Enhancement of Heat Transfer Performance in Sintered‐Core Heat Pipes Using CuO Nanofluid

ABSTRACT This study presents the design and construction of an experimental system for evaluating the thermal performance of heat pipes, using sintered‐wick heat pipes charged with CuO nanofluids. The device used in this study is a sintered‐wick heat pipe, in which the liquid return is driven by capillary forces within the porous wick structure. The effects of nanoparticle concentration and fill ratio on heat pipe performance were systematically investigated. A comparative analysis was performed between CuO nanofluid heat pipes and conventional deionised water heat pipes, focusing on thermal resistance, single heat pipe heat transport capacity and thermal start‐up performance. The results demonstrate that the effective thermal conductivity of a single heat pipe increases with increasing nanoparticle concentration, with an optimal liquid fill ratio of 40%–50% for heat pipes charged with 1.5 wt.% CuO nanofluid. Furthermore, under identical heating power, CuO nanofluid heat pipes exhibit a significantly faster thermal response time, with start‐up time reduced by approximately 1–2 s compared with those of conventional heat pipes.