Effects of pin-finned condensing surfaces on pool boiling in FC-72

In the present study, the boiling of FC-72 occurs from a smooth boiling surface (14 times 14 mm²) and its vapor is condensed by four different types of condensing surfaces (30 times 30 mm² base): a smooth surface and 1times1 mm² pin-finned surfaces of 2 mm high with 0.3 mm, 0.5 mm, and 1 mm array spacing. Boiling characteristics are investigated in detail for different condensing surfaces. For a smooth boiling surface, the results obtained display that the pin-finned condensing surface with 1 mm array spacing yields the best performance and the smooth condensing surface does the worst. Furthermore hysteresis phenomenon is substantially reduced by using the enhanced condensing surfaces