Liquid water transport in porous metal foam flow-field fuel cells: a two-phase numerical modelling and ex-situ experimental study
journal contributionposted on 2019-04-09, 08:17 authored by Ashley FlyAshley Fly, Kyoungmi Kim, John GordonJohn Gordon, Daniel ButcherDaniel Butcher, Rui Chen
Proton exchange membrane fuel cells (PEMFCs) using porous metallic foam flow-field plates have been demonstrated as an alternative to conventional rib and channel designs, showing high performance at high currents. However, the transport of liquid product water through metal foam flow-field plates in PEMFC conditions is not well understood, especially at the individual pore level. In this work, ex-situ experiments are conducted to visualise liquid water movement within a metal foam flow-field plate, considering hydrophobicity, foam pore size and air flow rate. A two-phase numerical model is then developed to further investigate the fundamental water transport behaviour in porous metal foam flow-field plates. Both the experimental and numerical work demonstrate that unlike conventional PEMFC channels, air flow rate does not have a strong influence on water removal due to the high surface tensions between the water and foam pore ligaments. A hydrophobic foam was seen to transport liquid water away from the initial injection point faster than a hydrophilic foam. In ex-situ tests, liquid water forms and maintains a random preferential pathway until the flow-field edge is reached. These results suggest that controlled foam hydrophobicity and pore size is the best way of managing water distribution in PEMFCs with porous flow-field plates.
This research was funded by the Engineering and Physical Sciences Research Council (EPSRC) under grant number EP/M023508/1 and EP/L015749/1, supported by the International Collaborative Energy Technology R&D Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and granted financial resources from the Ministry of Trade, Industry and Energy, Republic of Korea (No. 20148520120160).
- Aeronautical, Automotive, Chemical and Materials Engineering
- Aeronautical and Automotive Engineering