Estimation of the effective thermal conductivity of carbon felts used as PEMFC Gas Diffusion Layers

2008 ◽  
Vol 47 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Julien Ramousse ◽  
Sophie Didierjean ◽  
Olivier Lottin ◽  
Denis Maillet
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Gas Diffusion ◽  
Gas Diffusion Layers ◽  
Diffusion Layers

Effect of PTFE on Thermal Conductivity of Gas Diffusion Layers of PEM Fuel Cells

2013 ◽  
Author(s):  
Hamidreza Sadeghifar ◽  
Ned Djilali ◽  
Majid Bahrami
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Contact Resistance ◽  
Performance Modeling ◽  
Mechanistic Model ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
First Time

Through-plane thermal conductivity of 14 SIGRACET gas diffusion layers (GDLs), including series 24 & 34, as well as 25 & 35, are measured under different compressive pressures, ranging from 2 to 14 bar, at the temperature of around 60 °C. The effect of compression, PTFE loadings, and micro porous layer (MPL) on thermal conductivity of the GDLs and their contact resistance with an iron clamping surface is experimentally investigated. The contact resistance of MPL coated on GDL with the substrate of that GDL is measured for the first time in this paper. A new robust mechanistic model is presented for predicting the through-plane thermal conductivity of GDLs treated with PTFE and is successfully verified with the present experimental data. The model can predict the experimentally-observed reduction in thermal conductivity as a result of PTFE treatment and provides detailed insights on performance modeling of PEMFCs.

Anisotropic Heat Conduction Effects in Proton-Exchange Membrane Fuel Cells

2006 ◽  
Vol 129 (9) ◽  
pp. 1109-1118 ◽  
Author(s):  
Chaitanya J. Bapat ◽  
Stefan T. Thynell
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Thermal Contact ◽  
Current Collector ◽  
Gas Diffusion ◽  
Thermal Contact Conductance ◽  
Contact Conductance ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
Anisotropic Thermal Conductivity

The focus of this work is to study the effects of anisotropic thermal conductivity and thermal contact conductance on the overall temperature distribution inside a fuel cell. The gas-diffusion layers and membrane are expected to possess an anisotropic thermal conductivity, whereas a contact resistance is present between the current collectors and gas-diffusion layers. A two-dimensional single phase model is used to capture transport phenomena inside the cell. From the use of this model, it is predicted that the maximum temperatures inside the cell can be appreciably higher than the operating temperature of the cell. A high value of the in-plane thermal conductivity for the gas-diffusion layers was seen to be essential for achieving smaller temperature gradients. However, the maximum improvement in the heat transfer characteristics of the fuel cell brought about by increasing the in-plane thermal conductivity is limited by the presence of a finite thermal contact conductance at the diffusion layer/current collector interface. This was determined to be even more important for thin gas-diffusion layers. Anisotropic thermal conductivity of the membrane, however, did not have a significant impact on the temperature distribution. The thermal contact conductance at the diffusion layer/current collector interface strongly affected the temperature distribution inside the cell.

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