Investigation on Heat Transfer Performance and Micronization Boiling Phenomenon of Hydrophilic/Hydrophobic Surfaces

The boiling heat transfer performance of FC-72 was experimentally studied on hy- drophilic/hydrophobic surfaces based on micro-pin-finned structure. A high speed camera with microscope was applied to capture the micronization boiling phenomenon for the novel surfaces. From the comparison of the smooth chip and micro-pin-finned chip PF30-60 (micro-pin-fins with 30 µm fin side length and 60 µm fin height), it can be found that the hydrophilic/hydrophobic surfaces can efficiently decrease the wall temperature at the nucleate boiling onset, and can also decrease the wall superheat by 6∼9 K in the nucleate boiling region at the same heat flux. From the boiling phenomenon of the novel surface, it can be observed that large number of nucleation sites are formed in the micro-pin-finned area, and the hydrophilic property accelerates the departure of grown bubbles. These hydrophilic/hydrophobic surfaces can not only provide enough nucleation sites, but also prompt the bubble mergence and departure, enhancing boiling heat transfer greatly.