Frost and icing on transmission lines threaten the operational safety and efficiency of power system. Superhydrophobic (SHP) surfaces are considered as extremely promising anti-icing materials. The key to the anti-icing/frosting performance of SHP surfaces is to maintain Cassie condensation in low temperature and high humidity environments. Herein, the anti-frost mechanism of condensed droplets with Cassie state on the SHP surface was researched. 1060 aluminum plate with the same composition as the transmission aluminum conductor was used as the substrate. The SHP surfaces were prepared by anodic oxidation technique and low surface energy modification. The contact and roll angles of the SHP surface were 166.5° and 0.5°, respectively. Compared with the untreated surface, the frosting time of the SHP surface reached 180 min, which greatly delayed the formation and growth of frost. During the frosting process, the condensed droplets combined with each other, self-migrated and bounced on the surface with a high contact angle. This reduces the number of condensate droplets, increases the droplet spacing, and reduces the heat exchange between the solid and liquid, thus delaying the formation and growth of frost. Therefore, this study provides useful information for the development of anti-frost strategies for transmission aluminum conductors.
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