Design and manufacturing of novel hybrid metal-polymer heat exchangers
Nearly 60% of waste heat from industrial processes in the U.S. lies in low-temperature regime (<200°C). Current conventional metal heat exchangers for waste heat recovery (WHR) of low-grade heat are too expensive and subject to corrosion from condensates below <150°C. Polymers, although an attractive alternative to metals, have low thermal conductivity which typically makes them unsuitable for thermal applications. Combining thermally conductive metals with polymers can improve the thermal conductivity of the hybrid to be sufficient for WHR applications. Prior work has explored helically wound metal-polymer hybrid tubes as a means to combine the best aspects of both these materials for suitable heat exchanger performance. Here we show that compared to joining metal strips to polymer strips using laser welding, ultrasonic welding, or resistance seam welding, using adhesives to join the strips is easier for manufacturing and provides adequate joining strength. This work explores the improvement of a roll-to-roll setup to incorporate an adhesive dispensing system to manufacture heat exchanger tubes. To better understand conformal rolling, we develop a theoretical mechanics model to study important forces/factors responsible. Finally, we report data from a real-world demonstration for such heat exchangers within a campus building to analyze the performance and gauge potential under wider operating conditions. This work paves the way for realizing the cost-effective manufacturing of heat exchangers for low-grade WHR.
waste heat recovery, metal, polymer, helically wound, heat exchanger, adhesives, roll-to-roll, mechanics model, real-world demonstration
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign