Experimental study of an aluminum based three-dimensional thermosyphon heat sink with microscale enhancement structure

One of the most significant limitations to the advancement of electronics is the issue of heat dissipation. Currently, air cooling remains the most widely used method for heat dissipation due to the advantages of low cost and ease of maintenance. However, the traditional air-cooling method based on an all-solid heat sink is unable to keep pace with the rapid advancement in thermal power of electronics due to its limitation in area expansion by only solid fins. This study proposes an aluminum-based three-dimensional thermosyphon (3D-TS) coupling boiling-condensation heat transfer and forced air cooling as a means of overcoming the limitations of conventional air-cooling methods. Additionally, the incorporation of micro pin-fins enhances the boiling heat transfer and the overall performance of the three-dimensional thermosyphon. The performance of the three-dimensional thermosyphon is experimentally studied and analyzed under different volumetric flow rates using the environmentally friendly refrigerant R1233zd(E) as the working fluid. The results indicate that the total thermal resistance exhibits a biphasic response to heating power, with a decrease initially followed by an increase. This response is primarily attributed to the boiling mode on the substrate. Moreover, the micro pin-fins significantly enhance the boiling heat transfer on the substrate of the three-dimensional thermosyphon, enabling the three-dimensional thermosyphon to reach a minimum thermal resistance of 0.075 K/W and a maximum thermal dissipating power of 650 W with the temperature of the heating source below 85 °C. The three-dimensional thermosyphon proposed in this work is capable of meeting the cooling requirements of the majority of high-performance chips. This paper offers a valuable reference and guidance for the design and optimization of the phase-change devices.