The overheat temperature for the boiling process on metallic surfaces with microstructured relief

The boiling process is a very fast and effective heat exchange process that requires high demands on the heat transfer surface and its roughness. In former publications we described a new kind of heat transfer tubes with microstructures on the exterior wall surfaces. The microstructures, generated by the ion track and replica technique, enhance distinctly the vapour bubble generation process and therefore the boiling rate too. In this report we will present new results obtained by heating of massive copper rods whose surfaces were improved by replica microstructures. The copper rod, provided by a heat power cartridge, was completely dipped in a dielectric liquid that starts boiling on the rod surface and causes a high vapour bubble density. Depending on the heat flux, the overheat temperature of the heating copper rod was measured and compared with that for non-structured copper surfaces. Compared with plane surfaces, the heat transfer rate was increased by 200-300%