Prof. Liwu Fan

School of Energy Engineering, Zhejiang University, Hangzhou, China

E-mail: liwufan@zju.edu.cn

Bio

Dr. Liwu Fan is Professor in the School of Energy Engineering at Zhejiang University, Hangzhou, China. He is the Head of the Institute of Thermal Science and Power Systems, and is also affiliated with the State Key Laboratory of Clean Energy Utilization. Dr. Fan’s research activities have been focused on phase change and microscale heat transfer for thermal energy conversion and storage applications towards a decarbonized future. He has published more than 140 peer-reviewed international journal papers, including Nature, Nat. Commun., Adv. Mater., J. Fluid Mech., Int. J. Heat Mass Transfer, etc. He was conferred the Wu Chung-Hua Excellent Young Scholar Award on July 2021, and elected to the National Youth Talent Support Program on 2022.

Title

Surface slip enables highly-efficient phase-change heat transfer

Abstract

Slippery surfaces, as a type of functional surface with extremely low liquid friction and adhesion properties, have broad application prospects in areas such as drag reduction, anti-icing, surface-directed liquid transportation, and heat transfer during gas-liquid phase changes. During solid-liquid phase-change heat transfer, close-contact melting, as a mechanism for efficient heat transfer through an extremely thin micro-liquid film, has a strong correlation with the liquid film flow process. Therefore, introducing the slip effect can further achieve passive enhancement of the close-contact melting process. This report first explores the influence of introducing a slip surface on the close-contact melting process at the heated surface, achieves experimental measurement of the close-contact melting process on micro-structured slip surfaces, and modifies the existing heat transfer models. Focusing on the influence of introducing a slip surface in the non-contact melting area, this report innovatively proposes a slip-enhanced close-contact melting mechanism using a liquid-like surface, which can achieve an ultra-high heat-charging power density of over 1 MW/m³. At the same time, a convective heat transfer model and a thermal resistance analysis model are established to accurately predict the heat transfer characteristics enhanced by surface slip. This mechanism can be applied to various phase-change materials to achieve high-performance thermal management and thermal energy storage over a wide temperature range, providing a new technical path for constructing phase-change heat storage devices with both "high energy density" and "high power density".