An experimental study on the enhancement of nucleate boiling heat transfer using modified surfaces

In this study, the nucleate pool boiling of water on modified surfaces has been studied experimentally. The influence of surface modifications on the main parameters of nucleate boiling, such as boiling heat transfer coefficient and wall superheat, have been examined. This investigation has been carried out by an experimental set up equipped with a high-speed camera to extract the bubbles' departure diameter and frequency of bubble generation from captured images of the boiling phenomenon. The distilled water has been used as pool fluid, and all the experiments have been carried out at atmospheric pressure and saturated pool boiling conditions. It is observed that by adding grooves to the surface, the departure diameter of generated bubbles increases in comparison with a smooth surface. On the other hand, surface modifications reduce the departure frequency of bubbles. Experimental results also show that the heat transfer rate alters by the depth of the grooves on the solid surface. According to the results, the surface with 1.4 mm grooves has the highest boiling heat transfer coefficient, among others.