Dynamic performance of micro tubular fuel cells

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Transcript Dynamic performance of micro tubular fuel cells

Dynamic Performance of
Micro-Tubular Fuel Cells
Katie S. Howe
Centre for Hydrogen and Fuel Cell Research
SOFC Research group
www.fuelcells.bham.ac.uk
www.hydrogen-wm-scratch.info
Overview

Starting Point
– Fuel cells
– Status of dynamic performance
research
 Experimental Work
 Results
 Conclusions
 Next Steps
Starting Point: Fuel Cells

Change
electrochemical
energy into
useful electricity
 Like a battery,
but not limited
by how much
fuel they can
hold
Starting Point: Fuel Cells

mSOFCs
– Tubular
– Better thermal
shock
resistance
– Fewer issues
with sealing
Starting Point: Research Status
Load-following capability is vital for most
real-world applications
In the literature:
 Many papers on steady-state performance
 Some modelling work on dynamic
behaviour [1-3]
 ...but hardly any experimental results
[1] Nehter, P., 2006, Journal of Power Sources, 157(1), pp. 325-334.
[2] Ota, T., Koyama, M., Wen, C. J., Yamada, Y., and Takahashi, H., 2003, Journal of
Power Sources, 118(1-2), pp. 430-439.
[3] Serincan, M. F., Pasaogullari, U., and Sammes, N. M., 2009, Journal of Power
Sources, 194(2), pp. 864-872.
Starting Point: Research Status
Thermal transport time dominates dynamics[4]
 Readjustment time independent of step size[5]
 Undershooting of voltage when current rises[5]
– Size of undershoot related to step size

[4] Bhattacharyya, D., and Rengaswamy, R.,
2009, "A Review of Solid Oxide Fuel Cell
(SOFC) Dynamic Models," Ind. Eng. Chem.
Res., 48(13), pp. 6068-6086
[5] Achenbach, E., 1995, "Response of a solid
oxide fuel cell to load change," Journal of
Power Sources, 57(1-2), pp. 105-109.
Experimental Work - Method

Single cells made to in-house techniques[6]
– Operated at 750C
– Fuel: 20ml/minute of pure hydrogen

SolartronTM analytical 1400 Cell Test System
–Apply sets of square pulses of current
Paper
submitted[7] with precise details
[6] Dhir, A., 2008, "Improved Microtubular Solid Oxide Fuel Cells," PhD Thesis,
University of Birmingham,
[7] Howe, K. S.; Kendall, K., Transient Performance of Micro-tubular Solid Oxide
Fuel Cells. Journal of Fuel Cell Science and Technology 2010, .Paper Accepted –
awaiting editorial changes
Results
Transient behaviour:
Results
Conclusions

Short re-adjustment time of <0.5s is
independent of step size
– Agreement with models in the literature

No under-shooting of voltage on the change
– Suggests thermal transport is better than
expected in these tubes
Next Steps

Combination of cells into small stacks
– Higher powers
– Dynamic performance testing of stacks

Effects of changing to a hydrocarbon fuel
on transient performance
Acknowledgements
With thanks to...
My supervisors: Kevin Kendall and
Stephen Decent
My sponsors: RCUK and EADS Innovation
Works
Thank you!
Any questions?
www.fuelcells.bham.ac.uk