Enhancement of flow boiling heat transfer characteristics on diamond/Cu heterogeneous surface

Abstract

Surface treatment is an effective method of enhancing the heat transfer performance of flow boiling. Nonetheless, the majority of existing studies on surface treatment primarily concentrated on homogeneous materials and their associated zone design. Diamond/Cu, as a particle‐reinforced composite, exhibits heterogeneous surface properties and surface microstructures that play distinct roles in the heat transfer. To elucidate the synergistic effect of heterogeneous material surfaces and microstructures, pure copper surface (PC), untreated diamond/Cu surface (DC), and surface‐treated diamond/Cu surface (SDC) were prepared for this experiment. These surfaces demonstrate various combinations of diamond, copper, and their corresponding surface microstructures. DC, characterized by heterogeneous wetting properties, demonstrates a heat transfer coefficient that is 9%–24% higher than that of PC. No trend of decreased heat transfer capacity is observed in DC. The surface treatment of SDC results in the formation of a superhydrophilic CuO nanosheet structure, significantly enhancing both surface roughness and energy. SDC develops microcracks on the surface of diamond. The increased roughness provides numerous nucleation area for the hydrophobic diamond, enhancing the overall wettability of the surface when combined with the superhydrophilic CuO region. SDC demonstrates the advantage of enhanced flow boiling on the surface of heterogeneous materials. At the identical heat flux, SDC exhibits a reduction of 5 °C–10 °C in wall superheat and an increase of 38%–47% in heat transfer coefficient.This article is protected by copyright. All rights reserved.