Experimental investigation on enhancement of nucleate pool boiling heat transfer using hybrid wetting pillar surface at low heat fluxes

摘要

Hybrid wetting surfaces have the significant potential to enhance the performance of boiling heat transfer. In this paper, the hybrid wetting surfaces with pillars in millimeters are fabricated by the chemical deposition approach. Next the heat transfer coefficients for these fabricated surfaces are measured in nucleate pool boiling heat transfer experiment at low heat fluxes ranging from 3.75 to 18 W/cm(2). Under the same geometric size and heating power conditions, it is found that the heat transfer coefficients of the hybrid wetting surfaces are higher than the values of the spatially uniform wetting surfaces, regardless of hybrid modes. Additionally, the enhancement performance of boiling heat transfer among the hybrid wetting surfaces with different geometric sizes are distinctly different. Finally, the orthogonal array experiments relating to influential factors including wetting modes and geometric factors of the pillar surfaces are implemented, and further reveal the effects of the combination of these various influential factors on the performance of nucleate pool boiling heat transfer.