Condensation regimes inside a vapor chamber with hollow fins : effect of liquid holdup and ways to prevent it in two-phase cooling devices
Vapor chambers are among the most efficient passive two-phase cooling devices. They are frequently used for thermal management of electronics and commonly combined with air-cooled heat sinks with metallic fins. A novel design of vapor chamber, with integrated hollow fins, is introduced in this talk. This design lightens the cooling device and improves its performance thanks to the condensation of the working fluid inside the hollow fins.
The condensation regimes inside vapor chambers with hollow fins were observed for the first time thanks to the manufacturing of transparent polymer condensers. Several fin diameters were tested, showing that small diameters can lead to the formation of liquid plugs inside the fins. This deteriorates the heat transfer performance. Following the analysis of the condensation regimes, different ways of destabilizing liquid plugs and draining the condensate to the evaporator region are explored in this talk. In particular, the influence of the fin cross-section is numerically and experimentally investigated, considering fins of circular, polygonal or fluted cross-section. Condensers with interconnected hollow fins were also fabricated by additive manufacturing. They exhibit promising performances by pushing the operating limits further.
The findings presented in this talk could help improve the performance of two-phase cooling devices of small dimensions by mitigating liquid holdup in the condenser section. Many other devices could benefit from the optimization of their geometry to prevent channel occlusion.
Contact Frédéric Ayela for more information or to schedule a discussion with the seminar speaker.
Bérut E, Lips S, Lefèvre F, Sartre V. Experimental study of operating regimes in a vapor chamber with integrated hollow fins. Joint 20th International Heat Pipe Conference and 14th International Heat Pipe Symposium (20IHPC / 14IHPS), Gelendzhik (Russia), 7-10 September 2021.
Bérut E, Lips S, Sartre V, Lefèvre F. Tubes of non-circular cross-section to destabilize liquid plugs in heat transfer devices. Colloids and Surfaces A : Physicochemical and Engineering Aspects 655 (2022) 130230
Bérut E, Lips S, Lefèvre F, Sartre V. Condensation regimes inside a vapor chamber with transparent hollow fins of circular, triangular or fluted cross section. International Journal of Thermal Sciences 184 (2023) 107983.
Bérut E, Lips S, Sartre V, Joffre T, Lefèvre F. Interconnected hollow fins to eliminate capillary blockage in vapor chamber condensers. Applied Thermal Engineering 231 (2023) 120873.