Massenströme und Stromdichteverteilung in flüssig gespeisten Direkt-Methanol-Brennstoffzellen

The present study is concerned with the process-related and fluid dynamic analysis of liquid feed Direct-Methanol-Fuel-Cells (DMFC). The influence of operating and design parameters on the performance and the mass and heat balance is investigated. For this purpose experimental studies and modelling are combined. The results give hints to an optimised cell and stack design. Dependent on the flow field and manifold design experimental studies analyse the single- phase flow behaviour in the anode and cathode compartment. The single-phase studies on the anode are extended to two-phase flow analysis by a new experimental method based on the catalytic decomposition of H2O2. A model is presented that is in very good agreement with the experimental data. In order to describe a cell in operation the heat distribution and the electrochemical potentials of anode and cathode have to be known. Heat distribution is measured with an IR-camera. Experiments agree with the developed model. The electrochemical potentials and the methanol permeation are investigated in dependence of operating parameters and implemented in the existing model. Hence this verified model describes the DMFC three dimensionally. With this modelling tool the impact of operating and design parameters on the distribution of flow, temperature and current density is analysed. A single cell with an active area of 20cm² and a five cell short-stack with the same single cell area are investigated. The analysis shows that the current density distribution is strongly coupled with the temperature distribution. In order to achieve a homogenous flow distribution and a homogeneous current density, flow field and manifold design have to be balanced properly. Splayed manifolds give a homogeneous flow distribution on the anode, as they guarantee good CO2-bubble discharge.

Grantor dc:publisher

Forschungszentrum Jülich, Zentralbibliothek

Year dc:date

2003

Author dc:creator

• Bewer, Thomas

Contributors dc:contributor

• Stolten, Detlef

• info:eu-repo/classification/ddc/620
• Membranbrennstoffzelle
• Methanol
• Massestrom
• Elektrische Stromdichte
• Temperaturverteilung
• Ingenieurwissenschaften
• Brennstoffzellen
• DMFC
• Modellierung
• Zweiphasenströmung
• Stromdichteverteilung

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123136%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61474