Thermal-hydraulic performance investigation of an aluminium plate heat exchanger and a 3D-printed polymer plate heat exchanger

Polymer heat exchangers have gained interest due to their favourable qualities over metal heat exchangers, including being lightweight, low cost, and having reduced fouling and corrosion. In this work, two identical prototype, counter-flow, air-to-air, plate heat exchangers were fabricated, one from aluminium and the other from thermoplastic using a fused filament fabrication 3D printer. The results have shown that under dry operating conditions, typical of certain domestic appliances, both heat exchangers demonstrate similar thermal characteristics where the thermal effectiveness is greater than or equal to 0.50. Under wet conditions, the aluminium heat exchanger out performs the polymer heat exchanger, and this effect increases with an increasing temperature difference between the heat exchanger's hot-side inlet and cold-side inlet. In terms of both thermal and dehumidification capacity, the aluminium heat exchanger can outperform the polymer heat exchanger by as much as 22% and 38%, respectively. Despite the lower performance of the polymer heat exchanger, the absolute capacity and dehumidification rate are still reasonable and show promise for the use of polymer heat exchangers as a good alternative to metal heat exchangers in heat recovery applications in domestic appliances, for example, in clothes dryers or dehumidifiers, where operation takes place under both dry and wet operating conditions.