Study of pool boiling heat transfer with FC-72 on open microchannel surfaces

The paper presents investigations into pool boiling heat transfer for open microchannel surfaces. The experiments were carried out with saturated FC-72 at atmospheric pressure. Parallel microchannels fabricated by machining were about 0.2 to 0.4 mm wide and 0.2 to 0.5 mm deep. Analyzed surfaces with microchannels allowed to obtain heat transfer coefficients within the range of 6.1 - 9.8 kW/m(2)K, which in relation to the flat surface gives a 3 - 5 - fold increase in HTC. One of the reasons for the increase in the heat transfer coefficient when increasing the heat flux was the growing number of active nucleation sites at the bottom of microchannels and its side surfaces.