Influence of Thermophysical Wall Properties During Pool Boiling on Large Diamond and SiC Heaters

Abstract

The results of pool boiling experiments with synthetic diamond and silicon carbide (SiC) heaters are presented for water as the boiling liquid. The diamond and SiC heaters varied considerably in thermal conductivity, but they had smooth, nearly identical surfaces, which was also the case in regard to their contact angles for water. Temperature sensors and electric heating wires were directly vapor-deposited underneath the surfaces. The experiments were carried out with comparable large heaters (15 mm × 15 mm) for pure water under atmospheric pressure (1 bar) in a pool boiling cell. The heat transfer characteristics including the corresponding boiling curves were obtained. In prior work, it was found that the influence of the thermophysical wall properties might be substantial in the case of special heater geometries, leading to trapped bubbles, but no significant differences between both materials were observed in the case of conventional heater configurations.