A highly efficient and sustainable heat sink via liquid film boiling in hybrid mesh with active liquid supply. (1st February 2023) - Chen, Gong
Highlights: The heat sink realizes high thermal performance and sustainability simultaneously. High critical heat flux and heat transfer coefficient are achieved at low flow rate. Liquid film boiling with active liquid supply dominates the heat transfer. Critical heat flux is constrained by the vapor venting based on theory analysis. The concept proposed sheds light on thermal design for energy systems. Abstract: Two-phase heat transfer holds great potential to achieve efficient thermal management for high-power applications. However, achieving high thermal performance and sustainability simultaneously could be mutually exclusive. Here, we develop a rational design of a heat sink via liquid film boiling in hybrid mesh with active liquid supply. The heat sink exhibits a high critical heat flux of over 600 W/cm 2 and an average heat transfer coefficient of 38 W/cm 2 K at a flow rate of only 0.4 ml/s on a heating surface of 1 cm 2 with water under atmospheric conditions. The proposed architecture that comprises a superhydrophilic porous layer maintaining efficient liquid film boiling via a 3-D manifold decreasing wicking length enables huge heat dissipation with small pumping power and water consumption. The visualizations and the results of theoretical modeling demonstrate that the critical heat flux of the liquid film boiling on our functional structure is mainly constrained by the venting of vapor bubbles and increases with increase in flow rate before the liquid wicking limit is reached. The proposed strategy of employing liquid film boiling with minimum liquid transport distance may suggest a new design direction for efficient and sustainable two-phase cooling.