Advanced Air-Side Heat Transfer Surface Geometries Enabled by Additive Manufacturing

In a world with a decreasing supply of fresh water, industry is looking for design solutions that depend less on the availability of water. Dry-cooled condensers are one possibility, but they must compete with traditional water-cooled condensers in terms of cost, performance, and fan power. To improve performance, air-side heat transfer designs must be improved. Additive manufacturing offers the freedom to create designs that are difficult to manufacture with traditional methods. While the materials for additive manufacturing are not as conductive as the metals used in conventional heat exchangers, highly filled polymers do allow an improvement in conductivity and strength over traditional materials used in 3D printing. Also control over the printing material offers advantages such as the use of an antimicrobial infused filament. The ultimate goal of this research is to design an air-side geometry capable of achieving the same thermal performance (heat transfer rate and pressure drop under a given set of conditions) as a “gold standard” heat exchanger but at lower cost (i.e., using less material and/or less expensive manufacturing techniques). Because additive manufacturing allows for freedom in design, unconventional air-side geometries have been investigated using Computational Fluid Dynamics (CFD). The typical evaluation process for each geometry that has been considered includes an initial CFD simulation to validate the results and mesh convergence followed by an extensive parametric study of the geometry to develop correlations in terms of dimensionless parameters. The correlations are then implemented into an overall heat exchanger model in order to allow optimization of the heat exchanger