scholarly journals Analysis of reactant gas transport in a PEM fuel cell with partially blocked fuel flow channels

2005 ◽  
Vol 143 (1-2) ◽  
pp. 36-47 ◽  
Author(s):  
C.Y. Soong ◽  
W.M. Yan ◽  
C.Y. Tseng ◽  
H.C. Liu ◽  
Falin Chen ◽  
...  
2011 ◽  
Vol 110-116 ◽  
pp. 2301-2307
Author(s):  
P. Buaphad ◽  
P. Thamboon ◽  
C. Tengsirivattana ◽  
J. Saisut ◽  
K. Kusoljariyakul ◽  
...  

This work reports an application of reflective terahertz (THz) imaging for identification of water distribution in the proton exchange membrane (PEM) fuel cell. The THz radiation generated from relativistic femtosecond electron bunches is employed as a high intensity source. The PEM fuel cell is designed specifically for the measurement allowing THz radiation to access the flow field region. The THz image is constructed from reflected radiation revealing absorptive area of water presence. The technique is proved to be a promising tool for studying water management in the PEM fuel cell. Detailed experimental setup and results will be described.


Author(s):  
Hyung Hee Cho ◽  
Sanghoon Lee ◽  
Dong-Ho Rhee

Internal water management in proton exchange membrane (PEM) fuel cell has been considered as one of most significant key factors for its performance enhancement. It is because relative humidity of hydrogen and air is strongly related to the performance of PEM fuel cell in terms of H+ movement within the membrane. In addition, production of H2O by chemical reactions can bring several problems during concentration loss region since combination of vapor in supplying air and byproduct of chemical reaction should lead to excess H2O remaining in PEM fuel cell, resulting flooding phenomena which may block air flow channels. Therefore, in order to understand and manage such phenomena to enhance the performance of PEM fuel cell, especially under concentration loss region, this paper focuses on the visualization of the flooding phenomena and application of the modified flow path on the cathode separator for flooding reduction.


2016 ◽  
Vol 853 ◽  
pp. 410-415 ◽  
Author(s):  
Xiang Shen ◽  
Jin Zhu Tan ◽  
Yun Li

A proton exchange membrane (PEM) fuel cell is an electrochemical device that directly converts chemical energy of hydrogen into electric energy.The structure of the flow channel is critical to the PEM fuel cell performance. In this paper, the effect of the cathode flow channel baffles on PEM fuel cell performance was investigated numerically. A three-dimensional model was established for the PEM fuel cell which consisted of bipolar plates with three serpentine flow channels, gas diffusion layers, catalyst layers and PEM. Baffles were added in the cathode flow channels to study the effect of the cathode flow channel baffle on the PEM fuel cell performance. And then, numerical simulation for the PEM fuel cell with various cathode channel baffle heights ranging from 0.2 mm to 0.6 mm was conducted.The simulated results show that there existed an optimal cathode flow channel baffle height in terms of the electrochemical performance as all other parameters of the PEM fuel cell were kept constant. It is found that the PEM fuel cell had the good electrochemical performance as the flow channel baffle heights was 0.4mm in this work.


Author(s):  
Jingru Benner ◽  
Mehdi Mortazavi ◽  
Anthony D. Santamaria

Liquid water management is critical for Proton Exchange Membrane (PEM) fuel cell operation, as excessive humidity can lead to flooding and cell performance degradation. Water is produced in the cathode catalyst layer during the electrochemical reaction. If reactant gas streams become saturated, liquid water forms and must travel through anode and cathode Gas Diffusion Layers (GDLs) to reach flow channels for removal. Understanding the dynamic behavior of the droplet is critical to improve water removal strategies for PEM fuel cells. In this study a 3D, transient, two-phase model based on the Volume of Fluid (VOF) method was developed to study a single droplet in the gas channel. The formation, growth, and breakup of the droplet is tracked numerically and analyzed. The pressure drop across the droplet is monitored over time and compared with theoretical analysis. The droplet size and shape change over time for two different pore sizes are compared. The impact of various gases including air, helium, and hydrogen on droplet dynamics is presented. The viscous force and pressure force on the droplet and the drag coefficient are calculated.


2019 ◽  
Vol 92 (2) ◽  
pp. 311-318 ◽  
Author(s):  
R.M. Aslam ◽  
D.B. Ingham ◽  
M.S. Ismail ◽  
K.J. Hughes ◽  
L. Ma ◽  
...  

2006 ◽  
Vol 4 (3) ◽  
pp. 328-335 ◽  
Author(s):  
J. P. Feser ◽  
A. K. Prasad ◽  
S. G. Advani

Particle image velocimetry was used to measure 2D velocity fields in representative regions of interest within flow channels of interdigitated and single-serpentine proton exchange membrane (PEM) fuel cell models. The model dimensions, gas diffusion layer (GDL) permeability, working fluid, and flow rates were selected to be geometrically and dynamically similar to the cathode-side airflow in a typical PEM fuel cell. The model was easily reconfigurable between parallel, single-serpentine, and interdigitated flow fields, and was constructed from transparent materials to enable optical imaging. Velocity maps were obtained of both the primary and secondary flow within the channels. Measurements of the secondary flows in interdigitated and single-serpentine flow fields indicate that significant portions of the flow travel between adjacent channels through the porous medium. Such convective bypass can enhance fuel cell performance by supplying fresh reactant to the lands regions and also by driving out product water from under the lands to the flow channels.


Author(s):  
Mehdi Mortazavi ◽  
Kazuya Tajiri

Proton exchange membrane (PEM) fuel cells produce power with water and heat as inevitable byproducts. Accumulated liquid water within gas channel blocks the reactant flow and cause pressure drop along the gas channel. It is of extreme importance to accurately predict the liquid and gas two-phase flow pressure drop in PEM fuel cell flow channels. This pressure drop can be considered as an in-situ diagnostic tool that reveals information about the amount of liquid water accumulated within the flow channels. In this paper, the two-phase flow pressure drops are measured in ex-situ PEM fuel cell parallel flow channels. The pressure drops were measured for air mass fluxes of 2.4–6.3kg/m2s and water mass fluxes of 0.0071–1.28kg/m2s. These mass fluxes correspond to 2–5.33m/s and 7.14 × 10−6 – 0.0012m/s air and water superficial velocities, respectively. The measured two-phase flow pressure drops are then compared with different two-phase flow pressure drop models. Qualitative and quantitative comparison between the experimental results and existing models is provided in this work.


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