2 research outputs found
Liquid water transport in porous metal foam flow-field fuel cells: a two-phase numerical modelling and ex-situ experimental study
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
Supplementary information files for article: 'Liquid water transport in porous metal foam flow-field fuel cells: a two-phase numerical modelling and ex-situ experimental study'
Supplementary information files for article: 'Liquid water transport in porous metal foam flow-field fuel cells: a two-phase numerical modelling and ex-situ experimental study'. Abstract: 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