Session: 17-01: Poster Presentations

Paper Number: 167381

167381 - Numerical Investigations Reveal That the G-Ligament Network Offers the Best Performance, and Extends Pemfc Operational Range. 

Abstract: 

In this study, we demonstrated a promising solution by leveraging natural TPMS porous networks in fuel cell channels to optimize the mass transport and water management of PEMFC. Three types of networks have been applied namely the I-ligament network, G-ligament network, and G-sheet network. By numerical investigation, a comprehensive analysis of mass transport and water characteristics has been provided, which gives a first look at how the G-ligament network provides an outstanding performance among proposed flow fields. This flow field continuously guides airflow toward the GDL surface, enhancing reactant delivery and water extraction. With the ability to maintain low liquid saturation, high reactant uniformity, and a well-hydrated membrane, the G-ligament architecture is the optimal choice for mass transport and water management in PEMFCs. Thanks to its non-tortuous structure, the G-ligament porous network experiences the lowest pressure drop among proposed flow fields. On the other hand, the I-ligament network improves reactant distribution uniformity over CPFF due to its smaller local rib area, yielding an 8–15 % increase in current density in the ohmic loss region. However, it falls short of supporting forced convective gas penetration into the GDL. Nonetheless, the peak power density increased by 18 %. When comparing natural porous flow fields to 3DFF, the flow field based on Toyota Mirai outperforms the I-ligament network but is slightly behind the G-sheet network in the mass-limited region, with current densities of 1.82 A/cm2, 1.70 A/cm2, and 1.85 A/cm2 at a cell voltage of 0.4 V, respectively. Meanwhile, the G-ligament network achieves the highest current density of 1.91 A/cm2, which is 5 % higher than 3DFF. The novel flow fields show negligible improvement in terms of power density compared to 3DFF, however, the G-ligament network achieves an almost linear relationship in the polarization curve and consistent power density even at cell voltages down to 0.5 V, enabling PEMFC operation at high current densities. Briefly, we suggest using the G-ligament network as a solution for the challenges of water flooding and fuel starvation in PEMFCs. Future development of this solution could concentrate on enhancing fuel cell performance by identifying the optimal volume fraction for this flow field, thereby balancing the trade-off between electron and gas transport.

Highlights

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Natural TPMS porous networks have been applied to fuel cell flow fields.

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Numerical investigations reveal that the G-ligament network offers the best performance, and extends PEMFC operational range.

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Novel flow fields are compared with a conventional parallel flow field and the cutting-edge innovation from Toyota Mirai.

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Flow characteristics, oxidant distribution, water vapor content, membrane hydration, and liquid saturation are analyzed.

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3D fine-mesh flow field based on Toyota Mirai outperforms the I network but falls short of the G network in the mass-limited region.

Acknowledgements

This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. RS-2023-00217778). 

Presenting Author: Ock Taeck Lim university of ulsan

Presenting Author Biography: OCK TAECK LIM
2007- now Professor, School of Mechanical Engineering, University of Ulsan