scholarly journals Determination of Water Evaporation Rates in Gas Diffusion Layers of Fuel Cells

2018 ◽  
Vol 165 (9) ◽  
pp. F652-F661 ◽  
Author(s):  
Sreeyuth Lal ◽  
Adrien Lamibrac ◽  
Jens Eller ◽  
Felix N. Büchi
Keyword(s):  
Fuel Cells ◽  
Gas Diffusion ◽  
Water Evaporation ◽  
Gas Diffusion Layers ◽  
Diffusion Layers

scholarly journals Mass Transport Limitations of Water Evaporation in Polymer Electrolyte Fuel Cell Gas Diffusion Layers

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2967
Author(s):  
Adrian Mularczyk ◽  
Andreas Michalski ◽  
Michael Striednig ◽  
Robert Herrendörfer ◽  
Thomas J. Schmidt ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Liquid Water ◽  
Evaporative Cooling ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cell ◽  
Ex Situ ◽  
Water Evaporation ◽  
Evaporative Water ◽  
Gas Diffusion Layers ◽  
Diffusion Layers

Facilitating the proper handling of water is one of the main challenges to overcome when trying to improve fuel cell performance. Specifically, enhanced removal of liquid water from the porous gas diffusion layers (GDLs) holds a lot of potential, but has proven to be non-trivial. A main contributor to this removal process is the gaseous transport of water following evaporation inside the GDL or catalyst layer domain. Vapor transport is desired over liquid removal, as the liquid water takes up pore space otherwise available for reactant gas supply to the catalytically active sites and opens up the possibility to remove the waste heat of the cell by evaporative cooling concepts. To better understand evaporative water removal from fuel cells and facilitate the evaporative cooling concept developed at the Paul Scherrer Institute, the effect of gas speed (0.5–10 m/s), temperature (30–60 °C), and evaporation domain (0.8–10 mm) on the evaporation rate of water from a GDL (TGP-H-120, 10 wt% PTFE) has been investigated using an ex situ approach, combined with X-ray tomographic microscopy. An along-the-channel model showed good agreement with the measured values and was used to extrapolate the differential approach to larger domains and to investigate parameter variations that were not covered experimentally.

Prediction the Differences of Permeability Between Carbon Fiber Paper and Carbon Fiber Cloth in PEM Fuel Cells

2011 ◽  
Author(s):  
Yuan Gao
Keyword(s):  
Fuel Cells ◽  
Carbon Fiber ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Anisotropic Permeability ◽  
Gas Diffusion Layers ◽  
X Ray ◽  
Diffusion Layers ◽  
Carbon Fiber Cloth ◽  
Carbon Fiber Paper

This study is using the multiple relaxation time Lattice Boltzmann method to calculate the permeability of carbon fiber paper and carbon fiber cloth gas diffusion layers (GDL). The 3D gas diffusion layers are generated by X-ray computed tomography, This method involve generation of 3D digital model of gas diffusion layers acquired through X-ray micro-tomography at resolution of a few micros. The reconstructed 3D images were then read into the LBM model to calculate the anisotropic permeability of carbon fiber paper and carbon fiber cloth GDL. We investigated the relationships between the anisotropic permeability and porosity and compare the difference between the two different kinds of GDLs when they have the similar porosity. We also calculate the permeability with different viscosity and compare the two results from the carbon fiber paper and carbon fiber cloth. It is useful for selection of materials for high performance gas diffusion media and can improve the performance of the fuel cells.

scholarly journals Modeling Gas Diffusion Layers in Polymer Electrolyte Fuel Cells Using a Continuum-Based Pore-Network Formulation

2020 ◽  
Vol 97 (7) ◽  
pp. 615-626
Author(s):  
Pablo A. García-Salaberri ◽  
Iryna V. Zenyuk ◽  
Jeff T. Gostick ◽  
Adam Z. Weber
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Pore Network ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cells ◽  
Gas Diffusion Layers ◽  
Diffusion Layers

scholarly journals Gas Diffusion Layers in Fuel Cells and Electrolysers: A Novel Semi-Empirical Model to Predict Electrical Conductivity of Sintered Metal Fibres

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 855 ◽  
Author(s):  
Reza Omrani ◽  
Bahman Shabani
Keyword(s):  
Electrical Conductivity ◽  
Fuel Cells ◽  
Gas Diffusion ◽  
Metal Foams ◽  
Critical Porosity ◽  
Gas Diffusion Layers ◽  
Open Cell ◽  
Diffusion Layers ◽  
Sintered Metal ◽  
Closed Cell

This paper introduces novel empirical as well as modified models to predict the electrical conductivity of sintered metal fibres and closed-cell foams. These models provide a significant improvement over the existing models and reduce the maximum relative error from as high as just over 30% down to about 10%. Also, it is shown that these models provide a noticeable improvement for closed-cell metal foams. However, the estimation of electrical conductivity of open-cell metal foams was improved marginally over previous models. Sintered porous metals are widely used in electrochemical devices such as water electrolysers, unitised regenerative fuel cells (URFCs) as gas diffusion layers (GDLs), and batteries. Having a more accurate prediction of electrical conductivity based on variation by porosity helps in better modelling of such devices and hence achieving improved designs. The models presented in this paper are fitted to the experimental results in order to highlight the difference between the conductivity of sintered metal fibres and metal foams. It is shown that the critical porosity (maximum achievable porosity) can play an important role in sintered metal fibres to predict the electrical conductivity whereas its effect is not significant in open-cell metal foams. Based on the models, the electrical conductivity reaches zero value at 95% porosity rather than 100% for sintered metal fibres.

Sign in / Sign up

Export Citation Format

Share Document