Modified surfaces, as one of the important methods for improving pool boiling heat transfer performance, have begun to be applied to small modern thermal stress components and have achieved significant improvement effects. However, due to the complexity of the boiling process, the mechanism of boiling enhancement on modified surfaces remains unclear. In this paper, numerical methods are used to investigate the boiling heat transfer characteristics on three micro-structured surfaces: rectangular, trapezoidal, and triangular surfaces. The superheat and bubble behavior of the three structural surfaces are analyzed. The results show that at the same depth, the boiling heat transfer performance on rectangular and trapezoidal surfaces deteriorates, while the boiling heat transfer performance on triangular surfaces enhances, with the superheat reduced by 1.5K and the heat transfer coefficient increased by 30%. This is mainly due to the large reflux area of the triangular surface and the inclined side wall, which is conducive to the formation of vortices, thereby increasing the bubble detachment frequency. A composite structural surface is proposed to improve the boiling heat transfer performance in this paper. This paper can provides a reference for the design and optimization of micro-structured surfaces for enhanced pool boiling.

Pool boiling, Modified surfaces, Micro-structured surfaces, Heat transfer characteristics