Heat Transfer Enhancement due to Bubble Pumping in FC-72 Near the Saturation Temperature

The use of boiling heat transfer in the liquid immersion cooling of electronic components has always been hampered by the excessive superheat necessary to initiate nucleation in the fluorinated hydrocarbons used as dielectric cooling fluids. In an attempt to overcome some of these difficulties, an experimental study of the effects of nucleate pooling boiling, on the heat transfer from surface near the boiling surface was conducted. An experimental chamber was constructed which had a column of four horizontal wires spaced 2.5 cm vertically from each other. The lowest wire was progressively heated from the natural convection region through the nucleate boiling region. A study was made of the effects of the boiling wake from the lowest wire on heat transfer from the upper wires. Under certain conditions heat transfer enhancements of up to 30 were obtained.