Enhanced heat transfer technology for solar air heaters

Solar air heaters (SAHs) exhibited low thermal performance due to air thermal properties. To optimize the convective heat transfer between air and the absorber plate, researchers designed plenty of enhanced structures based on experimental and numerical analysis. This article reviewed the improvement methods of SAHs and emphasized the crucial role of thermodynamic models and evaluation criteria. Current research focuses on improving the convective heat transfer coefficient. In terms of enhanced structures, using flow deflectors, flow disruptors, corrugated absorber plates, and porous media improved collection efficiency. This result showed these enhanced structures could effectively further the performance of SAHs and provide new ways for sustainable energy utilization.