Enhancement of pool boiling heat transfer using 3D-printed groove structure

Abstract

Groove structures were fabricated by selective laser melting (SLM) technique to enhance saturated boiling heat transfer at atmospheric pressure. Prepared groove structures have different groove lengths and heights, and the printing material used is AlSi10Mg. Pool boiling experiments were explored with deionized water as the working fluid, and the heat transfer performance of different groove structures was compared based on smooth surface. It was found that the groove structure can significantly increase the boiling heat transfer coefficient (HTC) and critical heat flux (CHF) compared with the smooth surface. With the increase of groove length, the CHF of the groove structure gradually increases until it reaches the maximum at the groove length of 2.2 mm, which corresponded to the bubble departure diameter. Maximum CHF and HTC improvements were 3.1 times and 2 times, respectively. The HTC and CHF of groove structure decrease with the increase of groove height, which is due to the increase of liquid and vapor flow resistance in the groove. Difference of HTC of samples with the same structure size and different height declines with the increase of groove length. Groove structure facilitates gas-liquid flow and separation, thereby enhancing boiling heat transfer. The semi-melted powder bonding on the surface of the 3D-printed skeleton and the groove structure work together to improve the boiling heat transfer performance.