Experimental study on mechanism of boiling heat transfer of surface-mounted evaporative cooling system

Abstract

ABSTRACT The Boiling heat transfer technology has been applied to the field of heat dissipation of power electronic equipment. Due to the complexity of the boiling heat transfer mechanism, its heat transfer mechanism is still unclear, which limits the further improvement of the cooling efficiency of power electronic equipment. This study aimed to obtain the characteristics of boiling heat transfer in the liquid box of a self-circulating evaporative cooling system and establish an accurate calculation model for boiling heat transfer. To this end, we studied the boiling heat transfer process in a liquid box with a cross-sectional area of 180 mm × 20 mm. The experimental results reveal that bubble flow, Churn flow, and mist flow appear successively in the liquid box with an increase in thermal load. A new correlation for boiling in the liquid box is proposed by introducing a new dimensionless number Xnew, and the predicted boiling heat transfer coefficient and experimental data show agreement within 8%. This correlation further improves the calculation accuracy of the boiling heat transfer coefficient and provides a useful reference for engineering applications of the surface-mounted evaporative cooling system.