Characterisation of the diffusion properties of metal foam hybrid flow-fields for fuel cells using optical flow visualisation and x-ray computed tomography
journal contributionposted on 2018-06-19, 11:07 authored by Ashley FlyAshley Fly, Daniel ButcherDaniel Butcher, Q. Meyer, Michael Whiteley, Adrian SpencerAdrian Spencer, Chang Soo Kim, Paul Shearing, Daniel J.L. Brett, Rui Chen
The flow distribution behaviour of open-cell metallic foam fuel cell flow-fields are evaluated using ex-situ optical analysis and X-ray computed tomography (X-ray CT). Five different manifold designs are evaluated and flow distribution and pressure drop quantitatively evaluated with reference to applications in polymer exchange membrane fuel cells (PEMFC) and heat exchangers. A ‘hybrid’ foam flow-field is presented consisting of flow channels pressed into the foam to promote flow distribution and reduce pressure drop. Cross- and through-channel pressure drop measurements are conducted, along with X-ray CT analysis. Results using dyed water show that metallic foams provide excellent fluid distribution across the fuel cell flow-field, closely following the theoretical filling rate. The time for dye to cover 80% of the flow-field area was 61% faster with a foam flow-field then with no flow-field present. Pressure drop was seen to reduce with increasing foam inlet area to levels comparable to multi-serpentine flow-fields. The introduction of flow channels in the foam can further reduce pressure drop and provide more even filling of the foam, at the expense of increased residence time.
This work has been funded by the Engineering and Physical Sciences Research Council (EPSRC) under grant number EP/M023508/1 ‘Innovative concepts from electrode to stack’
- Aeronautical, Automotive, Chemical and Materials Engineering
- Aeronautical and Automotive Engineering