Phase change air cooling radiators achieve efficient heat dissipation through the synergistic effect of phase change materials (PCMs) and air cooling systems. Their internal structural design must focus on the flow of the PCM, heat transfer efficiency, and optimized air ducts to enhance overall heat dissipation performance.
PCM, as a core component, has a direct impact on heat dissipation efficiency through its distribution and packaging. Traditionally, PCMs are often incorporated into the PCM baseplate in blocks or granules, but this poses challenges such as high flow resistance and uneven heat transfer. Optimization options include employing porous media structures to increase the contact area between the PCM and air, promoting natural convection during the melting and solidification process. For example, encapsulating the PCM within a honeycomb or metal foam framework not only stabilizes the material's shape but also utilizes the framework's pore structure to guide airflow, creating a hybrid "phase change-convection" heat transfer mode and significantly improving thermal response speed.
The coupled design of the baseplate and heat sink fins is crucial for optimization. As the hub of heat transfer, the baseplate requires both high thermal conductivity and structural strength. A copper-aluminum composite substrate utilizes copper's high thermal conductivity to quickly collect heat, and aluminum fins expand the heat dissipation area. Regarding fin shape, traditional straight fins are prone to creating dead zones, while serrated or wavy fins can disrupt the boundary layer, enhance turbulence intensity, and improve convective heat transfer. Furthermore, fin spacing must be aligned with the fan's airflow volume to avoid excessively close spacing that increases air resistance or excessively close spacing that reduces heat transfer area.
Optimizing the air duct structure requires balancing airflow distribution with pressure drop. Traditional axial fan straight-flow designs are prone to localized overheating, while using a shroud or tapered duct can guide airflow evenly across the heat dissipation area. For example, adding a honeycomb-shaped flow-distributing mesh to the inlet of a phase change air cooling radiator improves airflow uniformity to over 90% and reduces eddy current losses. Furthermore, a gradually diverging/converging structure is used at duct cross-sectional changes, with the expansion angle kept to ≤15°, to reduce localized resistance and avoid efficiency degradation caused by airflow separation.
The coordinated control strategy for phase change materials and air cooling requires precise matching of heat load variations. When the device is in a low-power state, the phase-change material absorbs heat through latent heat, delaying fan startup and achieving silent operation. In high-power scenarios, the fan intervenes prematurely to accelerate the solidification of the phase-change material and prevent a sudden temperature rise. Integrated temperature sensors and intelligent algorithms dynamically adjust fan speed and the phase-change material's operating state, creating a "passive-active" hybrid cooling mode that balances energy efficiency and reliability.
The influence of material selection and manufacturing process on heat dissipation efficiency cannot be ignored. Phase-change materials, such as paraffin or fatty acid materials, must possess high latent heat, low supercooling, and chemical stability. The baseplate and fins are connected by brazing or diffusion welding to ensure a contact thermal resistance of ≤0.1K·cm²/W. Surface treatments such as anodizing or micro-arc oxidation improve radiant heat transfer efficiency, enhance corrosion resistance, and extend service life.
In practical applications, phase-change air cooling radiators must be customized for specific scenarios. For example, in data center servers, 3D printing technology is used to create a gradient pore structure, allowing the phase change material to melt rapidly at the inlet and solidify slowly at the outlet, creating a gradient heat exchange pattern of "heat absorption at the front and heat release at the back" to accommodate high-density heat flows. In outdoor communications equipment, tilted filters and self-cleaning coatings are used to reduce the impact of dust accumulation on the air duct, ensuring long-term stable operation.
Optimizing the internal structure of a phase change air cooling radiator requires a comprehensive approach encompassing multiple dimensions, including phase change material distribution, substrate-fin coupling, air duct design, coordinated control, material processing, and scenario adaptation. Through structural innovation and algorithm optimization, heat dissipation efficiency can be significantly improved, providing a reliable thermal management solution for high-power electronic equipment.
