A comparative study of pool boiling heat transfer in different porous artery structures

Abstract

• A novel porous artery structure is proposed to enhance the CHF of pool boiling. • Effects of microporous layer thickness and the artery depth are investigated. • The maximum heat flux reaches 465 W/cm 2 with DI water as the working fluid. • The inherent physical mechanisms of porous artery structure are elucidated. A novel porous artery structure is proposed and experimentally validated to enhance the pool boiling heat transfer performance based on the concept of “phase separation and modulation”. In the experiment, multiple rectangular arteries are formed in the bottom of a porous structure, and a thin copper microporous layer is placed between the heating surface and the rectangular arteries. Compared with conventional porous structures, this novel porous artery structure can effectively improve the pool boiling heat transfer performance due to i) increased nucleation site density, ii) improved liquid replenishment by capillarity, and iii) effective liquid/vapor phase separation. Experimental results show that comparing with boiling heat transfer on a plain surface, a 200% higher in CHF, and a 144% higher in heat transfer coefficient (HTC), together with a 59% lower in superheat at the onset of nucleate boiling (ONB) are obtained for this new structure. In addition, the effects of the top and bottom microporous layer thickness and the artery depth on the pool boiling heat transfer performance are investigated, and the inherent physical mechanisms are analyzed.