Investigative research on the heat exchangers with triply periodic minimal surface structures under two hybrid methods

• Two hybrid methods for generating TPMS heat exchangers were proposed. • The novel TPMS heat exchangers were evaluated from multiple angles. • The influence mechanism of heat transfer and flow performance was revealed. The triply periodic minimal surfaces (TPMS) serve as an ideal structure for next-generation heat exchanger (HE) designs. This paper introduces two hybridization methods—Proportional Hybridization (PHM) and Sigmoid Function (SF)—for TPMS structures based on Gyroid (G) and Schwartz Diamond (SD) types. The design freedom of HE is improved. The flow and heat transfer performance of TPMS-HEs are studied through experiment and simulation to investigate the hybridization effects. Based on the first and second laws of thermodynamics, the TPMS heat exchanger performance characteristics are comprehensively evaluated. The Nusselt number of G_HE is 48.85 % higher than that of SD_HE. The introduction of an equal proportion of PHM reduces the pressure drop of the SD_HE (48.3 %), and improves the Nu of the SD_HE (34.12 %). The heat transfer rate of PHM_0.9SD_0.1G heat exchange module (HEM) is 2.19 % and 29.57 % higher than that of PHM_SD and PHM_G, respectively. The efficiency of PHM_0.5SD_0.5G_HE is 8 % and 3.8 % higher than that of SD_HE and G_HE, respectively. The entropy generation of SD_HE is the smallest, and the entropy resistance of G_HE is the smallest. The heat transfer performance is improved by the SF hybrid method. The SF hybrid structure with SD-type and G-type as the inlets increases by 29.8 % and 32.6 % respectively compared with the G_HEM, and increases by 6.73 % and 9.03 % respectively compared with the SD_HEM. The gap of multi-dimensional analysis of hybrid TPMS-HEs is filled by the research. The hybridization method demonstrates significant potential for lightweight and efficient TPMS-HEs design.