Design of micro-nano structures for counter flow diverging microchannel heat sink with extraordinarily high energy efficiency

• Published in: Applied thermal engineering Vol. 209; p. 118229
• Main Authors: Jiang, Xingchi, Waqar Ali Shah, Syed, Liu, Jian, Li, Yuanjie, Zhang, Shiwei, Wang, Zuankai, Pan, Chin
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05-06-2022; Elsevier BV
• Subjects: Cooling rate; Cooling systems; Counter flow; Counterflow; Design modifications; Diverging microchannel; Energy dissipation; Energy efficiency; Flow boiling; Heat flux; Heat sinks; Heat transfer; High energy-efficiency; Micro-nano structure; Microchannels; Nanostructured materials; Nucleate boiling; Nucleation; Pumping; Single-phase flow; Two phase flow; Flow boiling; Micro-nano structure; Counter flow; Diverging microchannel; High energy-efficiency
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2022.118229

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•Micro-nano hybrid structure for counter flow diverging microchannels.•Highly stable two-phase flow and elimination of local dry out.•4.8 kW effective heat dissipation rate on a 3 × 4 cm2 cooling area.•Unprecedentedly high coefficient of performance of over 150,000 achieved.•Excellent energy-efficiency for cooling high power electronic devices.
In the current digital society, more energy-saving and reliable cooling systems are urgently needed for the flourishing electronic industry demanding a very high heat dissipation rate. Through the channel-to-channel heat transfer, a counter flow diverging microchannel heat sink has demonstrated to be a high performance cooling design in our previous studies. This work further integrates such an innovative design with surface modification of microscale cavities with optimal mouth diameter from the nucleation theory and nanoscale coating structures. The results of the present study demonstrate a significant enhancement on boiling heat transfer performance with the corresponding pumping power very close to that of the single-phase flow. Through highly efficient nucleate boiling from well-designed cavities with liquid replenished from the excellent wicking effect of nano-structure and stable two-phase flow, this study achieves a 4.8 kW effective heat dissipation rate on a 3 cm × 4 cm cooling area without sign of reaching the critical heat flux. Remarkably, an unprecedented coefficient of performance, defined as the heat dissipation rate to the pumping power, over 150,000, an order of magnitude higher than that reported in the literature, is accomplished.