Effects of Different Nanoporous Structures on the Heat Dissipation and Temperature-Rising Properties of Al Conductors

Increasing the ampacity of transmission lines can ensure safe operation while simultaneously achieving higher transmission capacity and energy-saving goals. Using a high-infrared-emissivity surface is an effective approach to enhancing the heat-dissipation performance of conductors and enabling low-cost capacity upgrades. In this study, a nanoporous structure was constructed on the surface of aluminum conductors by anodization. The influences of different pore diameters and pore depths on the infrared emissivity and current-induced temperature rise characteristics were systematically compared, and the optimal structure was fabricated on aluminum stranded conductors for performance validation. The results show that the nanoporous aluminum stranded conductor with a pore diameter of approximately 100 nm and a pore depth of approximately 30 μm achieves the highest ampacity, with a 26.6% increase compared with the bare aluminum stranded conductor. The improvement can be attributed to (1) enhancing thermal emissivity to strengthen radiative cooling, and (2) increasing the effective surface area to promote convective heat transfer. Therefore, the as-prepared nanoporous aluminum stranded conductor exhibits excellent heat dissipation performance and demonstrates promising application potential in the capacity upgrading of transmission conductors.