KAGAKU KOGAKU RONBUNSHU, Vol.29, No.1, 131-136, 2003
Fundamental study for augmenting evaporative cooling by wick layer attached to heat transfer surface
A new technique to augment the evaporative heat transfer by setting a thin wick layer oil the heating surface is presented. The fundamental heat transfer characteristic was evaluated by measuring the evaporation time of a droplet on the heating surface with and without the wick layer. Further, a series of quench experiments were carried out to evaluate the characteristics when the liquid supply reaches the maximum. One feature of this technique is its easy applicability to ordinary heat transfer surfaces. Glass fiber and silicon carbide fiber were tested as the wick layer, which was attached to the heating surface by a wire net. The evaporation time was appreciably shortened at a higher surface temperature when the wick layer was present. The cooling velocity of the quench process is augmented at a high liquid temperature. The cause of this high performance is considered to be a holding effect of liquid on the surface and an increase in effective wetness between liquid and solid by the suction pressure in the wick layer.