Development of a flow-optimized HT-PEM fuel cell stack using a novel high-resolution flow sensor and efficient simulation schemes
Due to positive characteristics like slow degradation, higher efficiency and better
handling, high-temperature polymer electrolyte membrane (HT-PEM) fuel cells
are already established in many areas as back-up systems, remote power supply
or combined heat-and-power systems. The coupling of several fuel cells for
higher voltages still poses a challenge, as it introduces flow distribution inequalities,
which lead to significantly lower overall efficiency. Compensating this inequality
is a complicated task, as the state of the flow is generally unknown and
hard to measure. Based on a previous cooperation (project 407 ZBG), this project
addresses several issues of HT-PEM fuel cell stacks.
A novel flow sensor based on the Laser Doppler Flow Profile Sensor has been set
up. It uses an electro-optical modulator for time-division multiplexing in the
10 MHz range to enable the investigation of near-wall flows in confined spaces
< 1 mm with high spatial resolution using fluorescing particles. Furthermore, sophisticated simulation schemes are be developed, which will encorporate relevant
physical aspects like transport of warmth and electrochemical reactions as
a reduced model to enable the simulation of whole fuel cell stacks. To this date,
this is near impossible as multiphysics simulation and will greatly facilitate the apriori
development of HT-PEM systems. Validation and calibration of the simulations
will be done using the novel flow sensor. The project will enable time-efficient
pre-production investigation of systems with higher efficiency.
Staff: F. Bürkle, F. Schmieder
Period: 12/2016 – 05/2019
Partner: Zentrum für BrennstoffzellenTechnik GmbH (ZBT), Duisburg
Electrooptical modulator for binary amplitude modulation up to 30MHz © Felix Schmieder
Schematic of a fuel cell stack in z-configuration with simulated flow profile © ZBT GmbH
F. Schmieder, M. E. Kinaci, J. Wartmann, J. König, L. Büttner, J. Czarske, S. Burgmann, A. Heinzel “Investigation of the flow field inside the manifold of a real operated fuel cell stack using optical measurements and Computational Fluid Mechanics”, Journal of Power Sources 304C:155-163, 2016. (DOI: 10.1016/j.jpowsour.2015.11.010)
A. E. Ramos Ruiz, C. Schober, F. Schmieder, F. Moyon, L. Feierabend, M. Dues, J. W. Czarske, L. Büttner „Hochaufgelöste Strömungsmessungen in den Mikrokanälen einer Brennstoffzelle mittels Zeitmultiplex- Laser-Doppler-Geschwindigkeitsprofilsensor“, 26. GALA-Fachtagung “Experimentelle Strömungsmechanik”, S. 17.1–17.8, 4. – 6.09.2018, Rostock