The heat dissipation structure design for dense bus ducts must focus on the core objectives of "reducing heat accumulation and enhancing heat conduction and dissipation." By comprehensively optimizing the conductor characteristics, insulation material performance, and casing functionality, a complete heat dissipation path is constructed from the source to the outside world, preventing conductor overheating during long-term operation. First, the structural design of the conductor itself is the foundation of heat dissipation, requiring both current carrying capacity and thermal efficiency. Conductors with rectangular or irregular cross-sections are typically used. Compared to circular cross-sections, these cross-sections increase the contact area between the conductor, the insulation material, and the casing, allowing heat generated during operation to be transferred to the outside through contact. Furthermore, conductors are arranged with appropriate spacing. Even in densely packed arrangements, the distance between phases and adjacent conductors is controlled to prevent heat accumulation within the gaps between conductors, leading to localized high-temperature zones. The presence of gaps also allows air to act as a secondary heat transfer medium, dissipating some heat through mild convection.
The choice and application of insulation materials also directly impact heat dissipation. They must not only meet insulation requirements but also possess good thermal conductivity. Insulation materials with high thermal conductivity, such as modified epoxy resin or high-temperature-resistant insulating paper, are preferred. These materials quickly transfer heat from the conductor surface to the dense bus duct casing, preventing heat from being trapped between the conductor and the insulation layer. Furthermore, the insulation material is wrapped thinly and evenly to prevent excessively thick insulation layers from forming a thermal barrier. Some designs also incorporate microscopic thermal channels within the insulation layer to further enhance heat transfer efficiency. Furthermore, these insulation materials must exhibit excellent high-temperature stability to prevent aging and deterioration at high temperatures, which could hinder heat dissipation and pose safety risks.
As the key carrier for heat dissipation, the casing's structure and material design are particularly important. The casing is often made of aluminum alloy or cold-rolled steel, both of which have excellent thermal conductivity. These metals quickly absorb heat transferred from the insulation layer and diffuse it across the entire casing surface through conduction. To expand the heat dissipation area, the casing surface is often designed with longitudinal or transverse heat dissipation ribs. These ribs not only enhance the casing's mechanical strength but also significantly increase the contact area with the air, enhancing the efficiency of natural convection heat dissipation. The ribs are arranged to follow the natural flow of air, for example, along the length of the dense bus duct, allowing rising hot air to flow smoothly through the gaps between the ribs, accelerating heat dissipation. Furthermore, the casing's sealing design must balance protection and heat dissipation. Rather than a completely enclosed structure, ventilation holes or louvers with dust screens are installed at strategic locations to prevent dust and moisture from entering and affecting insulation while allowing cool air to enter the casing, creating convection with the hot air inside and assisting in heat dissipation. Some dense bus ducts used in high-temperature environments also employ a double-layer casing with air flow channels formed within the interlayer to enhance heat dissipation through air circulation.
The connectors of dense bus ducts are a key area of focus in heat dissipation design. Due to contact resistance, these connectors are prone to generating excess heat during operation. Poor heat dissipation can easily lead to localized overheating. To address this, the connectors are constructed using materials with both excellent electrical and thermal conductivity to reduce the heat generated by contact resistance. Furthermore, the connector housing features a unique heat dissipation structure, such as adding localized heat dissipation ribs or using thicker thermally conductive materials, to quickly transfer heat generated by the connector to the outside. Slight ventilation gaps are also included in the connector seal to ensure that localized heat can be dissipated quickly and prevent accumulation within the connector.
Furthermore, the installation method of dense bus ducts will be optimized with heat dissipation design. During installation, sufficient heat dissipation space will be reserved between the dense bus duct and the wall and equipment to avoid air circulation obstruction caused by close installation. For suspended dense bus ducts, open brackets will be used to ensure that the dense bus duct is fully exposed to air on all sides, enhancing natural convection. In high-temperature or closed installation environments, the installation spacing will be adjusted and ventilation devices will be added to create good heat dissipation conditions for the dense bus duct. At the installation level, the heat dissipation structure will be supplemented to ensure that the overall heat dissipation efficiency meets long-term operation requirements, avoid overheating of the conductor due to heat not being able to dissipate in time, and ensure the stability and safety of the dense bus duct.
