Water immersion cooling of high power density electronics

By Patrick Birbarah, Tarek Gebrael, T. Foulkes, Andrew Stillwell, A. Moore, Robert C. N. Pilawa-Podgurski, Nenad Miljkovic. 2020

200 citations recorded by the source corpus.

Abstract Thermal management of power electronic systems is a key bottleneck to power densification. Single phase cooling is limited to low heat transfer coefficients ( μ m in preventing current from leaking between the electronic components and the surrounding water when the system is subjected to voltages up to 200 Volts. Furthermore, we provide the heat flux and convection heat transfer coefficient obtained in 3 M Novec 72DE and 7300 dielectric fluids, water, and a 50/50 in volume mixture of water and ethylene glycol (WEG) as a function of hot-spot-to-fluid temperature difference in both natural convection and nucleate pool boiling regimes. Gallium Nitride (GaN) transistors with different board-mounting techniques and thermal pad locations are used as heat sources. Heat fluxes up to 562 W/cm2 are measured in water. As a proof of concept, water immersion cooling is tested successfully on a 2 kW power converter operating at 97.2% efficiency in deionized water. This study not only demonstrates immersion cooling in water of high-power density electronics, but also develops design guidelines for cooling of electronic components through the use of novel electrically insulating coatings coupled with attractive electrically conducting cooling media.

Subfields: Materials Chemistry, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/62c0a061d57505650b998578b519c7cb203fcf6d