Experimental investigation on heat transfer characteristics of copper heat exchangers based on triply periodic minimal surfaces (TPMS)

The Triply Periodic Minimal Surface (TPMS) demonstrates unparalleled advantages in heat transfer performance. However, recent study primarily focuses on experiments involving single-phase working fluids in low thermal conductivity heat exchangers made of aluminum or plastics, or simulation studies on parts rather than the overall heat exchanger. In this study, we successfully utilized additive manufacturing to create three high thermal conductivity pure copper TPMS-structured heat exchangers (Primitive, Gyroid, and Fischer-Koch S). A test rig was set up for heat transfer performance evaluation using refrigerant (R134a) and a coolant solution (50% ethylene glycol-water) for the three pure copper TPMS heat exchangers. The j/f factor of the Fischer-Koch S structure increased by 358.4% compared to traditional plate heat exchangers, and Gyroid structure improved by 178.1%. The manufactured three copper TPMS heat exchangers exhibited higher volumetric heat transfer rates compared to TPMS structures reported in literature, with the Fischer-Koch S heat exchanger showing a 47.8% increase. This study, in contrast to the extensively discussed Gyroid structure in the literature, highlights the substantial potential of the Fischer-Koch S structure, particularly as a pure copper two-phase heat exchanger within the thermal management system of electric vehicles.