Juncheng Jiang

In-situ hydrogen production via methanol steam reforming (MSR), a strongly endothermic and multicomponent process, imposes stringent demands on catalyst supports. Bioinspired triply periodic minimal surface (TPMS) architectures, featuring superior structural characteristics, offer exceptional potential for overall reaction performance intensification. In this study, representative TPMS topologies were constructed via mathematical geometric modeling, with a conventional micro-pin-fin structure as the benchmark, and a fully coupled multiphysics model, including fluid flow, heat transfer, mass transport, and surface reactions, was developed to elucidate the mechanisms by which distinct topological characteristics of the catalyst supports govern flow disturbance, as well as the corresponding influence on the heat and mass transfer performance of the system. The intrinsic reaction characteristics of MSR over TPMS supports were further revealed, alongside an analysis of the effects of key operating parameters. Furthermore, high-precision TPMS supports were fabricated via additive manufacturing and integrated into the microreactor platform. The results demonstrate that, compared with the benchmark, TPMS supports deliver improvements in heat transfer, mass transfer, and catalytic performance ranging from 7.1% to 151.1%, 3.7% to 202.9%, and 3.5% to 73.2%, respectively, with the Lidinoid exhibiting the best overall performance. The experimentally measured performance rankings agreed closely with the numerical predictions, validating the reliability of the simulation analysis. This work establishes a topology-governed transport-reaction coupling analysis framework, confirming the viability of TPMS architectures as efficient catalyst supports and providing design guidance for the intensification of solid-catalyzed reactions.

To improve immersion cooling for mitigating thermal runaway in lithium-ion batteries, boron nitride (BN) nanofluids with different volume fractions were prepared using deionized water/2-methyl-1,3-propanediol as the base fluid and polyvinylpyrrolidone as the dispersant. The dispersion stability, thermophysical properties, and thermal runaway suppression performance of the nanofluids were systematically evaluated. Results showed that BN concentration strongly affected both long-term stability and heat transfer performance. Nanofluids with 0.1-0.2 vol% BN remained uniformly dispersed without visible sedimentation after 120 days, while the 0.4 vol% BN nanofluid exhibited only slight sedimentation after 14 days but still maintained acceptable dispersion stability. Meanwhile, 0.4 vol% BN delivered the highest thermophysical enhancement, with thermal conductivity and specific heat capacity increased by 8.1% and 11.0%, respectively, compared with the base fluid. During battery thermal runaway tests, the 0.4 vol% BN nanofluid reduced the peak battery temperature by 2.4-4.3% and the temperature rise rate by 9.7-9.9%, and also suppressed battery mass loss and smoke temperature, with more pronounced effects at high state of charge. Therefore, rather than simply showing the best overall performance, the 0.4 vol% BN nanofluid achieved the most favorable compromise between dispersion stability, thermophysical enhancement, and thermal runaway mitigation, demonstrating strong potential as an immersion-cooling medium for lithium-ion battery safety applications.