Condensing Characteristics of Pin-finned Surfaces on Pool Boiling in FC-72

As the electronic industry rapidly develops, the heat flux from state-of-the-art electronics increases up to $10^6\;W/m^2$ . For this reason, the development of a new cooling technology for high heat flux applications is strongly required. Recently, some cooling technologies using boiling and condensation of working fluid are being adopted to overcome such a technical barrier. In the present study, a smooth boiling surface ( $14{\times}14\;mm^2$ ) was immersed in FC-72 and its vapor was condensed by four different types of condensation surfaces ( $30{\times}30\;mm^2$ base). The condensing surfaces were composed of a smooth surface and $1{\times}1\;mm^2$ pin-finned surfaces of 2 mm height with 0.3, 0.5 and 1 mm array spacing. Boiling and condensing characteristics were investigated in detail on their combinations of boiling and condensing surfaces. For a smooth boiling surface the results obtained showed that the pin-finned condensing surface with 1 mm array spacing yielded the best performance and the smooth condensation surface did the worst. Furthermore hysteresis phenomena could be reduced by using enhanced condensing surfaces.