Design and Fabrication of Heat Exchangers Using Thermally Conductive Polymer Composite

Polymer heat exchangers (HXs) are lightweight and cost-effective due to the affordability of raw polymer materials. However, the inherently low thermal conductivity (TC) of polymers limits their application in HXs. To enhance thermal conductivity polymer composites, two types of diamond powders, with particle sizes of 0.25 µm and 16.7 µm, were used as fillers, while Acrylonitrile Butadiene Styrene (ABS) served as the matrix. Composite polymer samples were fabricated, and their density and thermal conductivity were tested and compared. The results indicate that fillers with larger particle sizes tend to exhibit higher thermal conductivity. A polymer HX based on a Triply Periodic Minimal Surface (TPMS) structure was designed. The factors influencing the efficiency of polymer HXs were analyzed and compared with those of metal HXs. In polymer HXs, the polymer wall is the primary source of heat resistance. Additionally, the mechanical strength of 3D-printed polymer parts was evaluated. Finally, an HX was successfully fabricated using a polymer composite containing 50 wt% diamond powder via 3D printing.