Design of Helical-Grooved Pipes for Direct-Immersion Liquid-Cooled Ultra-Fast Charging Cables

Direct-immersion liquid-cooled charging cables, which feature high heat dissipation efficiency, has a wide range application in pile-side electrical connections of high-power mobile charging equipment. However, power line conductors in the cable may deviate from the center of liquid-cooling pipes under external forces, since power line conductors are only fixed by rigid connection components at both ends during use. The deviation will result in uneven heat distribution on cross-section of liquid-cooling pipes, leading to local thermal aging of the pipes and thus reducing service life of the cables. To address the issue, a liquid-cooling pipe model with helical-grooved channels was proposed in the paper, which could utilize its geometric structure to induce transverse liquid flow and enhance heat transfer. In the meantime, COMSOL Multiphysics was employed for simulation calculation. Results showed that liquid-cooling pipes with internal helical-groove channels could effectively improve lateral temperature uniformity when the power line was eccentric by improving fluid motion shape. The achievement could provide theoretical support and technical path for efficient thermal management of high-power charging station cables.