High Heat Flux Evaporation of Low Surface Tension Liquids from Nanoporous Membranes

作者：Daniel F. Hanks, Zhengmao Lu, Jay Sircar, Ikuya Kinefuchi, Kevin R. Bagnall, Todd Salamon, Dion S. Antao, Banafsheh Barabadi, Evelyn N. Wang · 发表于：ACS Applied Materials & Interfaces · 年份：2020 · DOI：10.1021/acsami.9b20520 · 被引用次数：78 · 研究领域：Heat Transfer and Boiling Studies、Solar-Powered Water Purification Methods、Gas Dynamics and Kinetic Theory

Water is often considered as the highest performance working fluid for liquid–vapor phase change due to its high thermal conductivity and large enthalpy of vaporization. However, a wide range of industrial systems require using low surface tension liquids where heat transfer enhancement has proved challenging for boiling and evaporation. Here, we enable a new paradigm of phase change heat transfer, which favors high volatility, low surface tension liquids rather than water. We utilized a nanoporous membrane of ≈600 nm thickness and <140 nm pore diameters supported on efficient liquid supply architectures, decoupling capillary pumping from viscous loss. Proof-of-concept devices were microfabricated and tested in a custom-built environmental chamber. We used R245fa, pentane, methanol, isopropyl alcohol, and water as working fluids with devices of total membrane area varying from 0.017 to 0.424 cm 2 . We realized a device-level pure evaporation heat flux of 144 ± 6 W/cm 2 for water, and the highest evaporation heat flux was obtained with pentane at 550 ± 90 W/cm 2 . We developed a three-level model to understand vapor dynamics near the interface and thermal conduction within the device, which showed good agreement with experiments. We then compared pore-level heat transfer of different fluids, where R245fa showed approximately 10 times the performance of water under the same working conditions. Finally, we illustrate the usefulness of a figure of merit extracted from the kinetic...