Effect of Bolts Locking Sequence on Flow-Channel Plate in Micro-PEMFC

2008 ◽  
Author(s):  
Chi-Hui Chien ◽  
Shih-Chun Li ◽  
Wei-Tsung Hsu ◽  
Chih-Wei Lin
Keyword(s):  
Fuel Cell ◽  
Three Dimensional ◽  
Deformation Mode ◽  
Pem Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Flow Channel ◽  
Membrane Electrode ◽  
Cell Assembly ◽  
Channel Plate

The design and method of cell assembly play important roles in assessing the performance of PEM fuel cell. The cell assembly will affect the contact behavior between the bipolar plates, flow-channel plates, gas diffusion layers (GDLs) and membrane electrode assembly (MEA). From the past studies, it is noted that the flow-channel plates in the cell will be deformed while the cell was assembled by locking with bolts. This phenomenon may lead to leakage of fuels, high contact resistance and malfunctioning of the cells. The main aim of this research is to study the variation of the deformation mode of the flow-channel plat in a micro-PEM fuel cell assembly subjected to different bolts locking sequences. The commercial FEM package, ANSYS, was adopted to model the three-dimensional single micro-PEMFC FEM model and the numerical simulation analyses were performed. The effect of the bolts locking sequence on the deformations of flow-channel plate in the micro-PEMFC was presented.

Investigation of Thermal Influence on the Assembly of Polymer Electrolyte Membrane Fuel Cell Stacks

2012 ◽  
Vol 512-515 ◽  
pp. 1509-1514
Author(s):  
Lin Fa Peng ◽  
Dian Kai Qiu ◽  
Pei Yun Yi ◽  
Xin Min Lai
Keyword(s):  
Thermal Expansion ◽  
Fuel Cell ◽  
Contact Pressure ◽  
Proton Exchange Membrane ◽  
Three Dimensional ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Fe Model ◽  
Assembly Process

The assembly force in a proton exchange membrane fuel cell (PEMFC) stack affects the characteristics of the porosity and electrical conductivity. Generally, the stack is assembled at room temperature while it’s operated at about 80 °Cor even higher. As a result, the assembly pressure can’t keep constant due to thermal expansion. This paper focuses on the contact pressure between membrane electrode assembly (MEA) and bipolar plates in real operations. A three-dimensional finite element (FE) model for the assembly process is established with coupled thermal-mechanical effects. The discipline of contact pressure under thermal-mechanical effect is investigated. A single cell stack is fabricated in house for the analysis of contact pressures on gas diffusion layer at different temperatures. The results show that as the temperature increases, contact pressure increases due to thermal expansion. It indicates that the influence of thermal expansion due to temperature variation should be taken into consideration for the design of the stack assembly process.

Three-dimensional model of a 50 cm2 high temperature PEM fuel cell. Study of the flow channel geometry influence

2010 ◽  
Vol 35 (11) ◽  
pp. 5510-5520 ◽  
Author(s):  
Justo Lobato ◽  
Pablo Cañizares ◽  
Manuel A. Rodrigo ◽  
F. Javier Pinar ◽  
Esperanza Mena ◽  
...  
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Three Dimensional ◽  
Pem Fuel Cell ◽  
Flow Channel ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Channel Geometry ◽  
Cell Study ◽  
High Temperature Pem

Lattice Boltzmann Modeling of Water Cumulation at the Gas Channel-Gas Diffusion Layer Interface in Polymer Electrolyte Membrane Fuel Cells

2014 ◽  
Vol 11 (6) ◽  
Author(s):  
Dario Maggiolo ◽  
Andrea Marion ◽  
Massimo Guarnieri
Keyword(s):  
Fuel Cell ◽  
Diffusion Layer ◽  
Lattice Boltzmann ◽  
Three Dimensional ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Vapor Condensation ◽  
Relative Height ◽  
Gas Channel

Several experiments have proved that water in liquid phase can be present at the anode of a PEM fuel cell due to vapor condensation resulting in mass transport losses. Nevertheless, it is not yet well understood where exactly water tends to cumulate and how the design of the gas channel (GC) and gas diffusion layer (GDL) could be improved to limit water cumulation. In the present work, a three-dimensional lattice Boltzmann based model is implemented in order to simulate the water cumulation at the GC–GDL interface at the anode of a PEM fuel cell. The numerical model incorporates the H2–H2O mixture equation of state and spontaneously simulates phase separation phenomena. Different simulations are carried out varying pressure gradient, pore size, and relative height of the GDL. Results reveal that, once saturation conditions are reached, water tends to cumulate in two main regions: the upper and side walls of the GC and the GC–GDL interface, resulting in a limitation of the reactant diffusion from the GC to the GDL. Interestingly, the cumulation of liquid water at the interface is found to diminish as the relative height of the GDL increases.

Numerical Study on the Influence of Cathode Flow Channel Baffles on PEM Fuel Cell Performance

2016 ◽  
Vol 853 ◽  
pp. 410-415 ◽  
Author(s):  
Xiang Shen ◽  
Jin Zhu Tan ◽  
Yun Li
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Numerical Study ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Flow Channel ◽  
Proton Exchange ◽  
Cell Performance ◽  
Fuel Cell Performance ◽  
Flow Channels

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.

In-Situ Measurements of Water Transfer Due to Different Mechanisms in a PEM Fuel Cell

2007 ◽  
Author(s):  
Attila Husar ◽  
Andrew Higier ◽  
Hongtan Liu
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Pem Fuel Cells ◽  
Water Transfer ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Order Of Magnitude

Water management is of critical importance in a proton exchange membrane (PEM) fuel cell. Yet there are very limited studies of water transfer through the membrane and no data are available for water transfer due to individual mechanisms through the membrane electrode assembly (MEA) in an operational fuel cell. Thus it is the objective of this study to measure water transfer through the MEA due to different mechanisms through the membrane electrode assembly (MEA) of an operational PEM fuel cell. The three different mechanisms of water transfer, i.e., electro-osmotic drag, diffusion and hydraulic permeation were isolated by specially imposed boundary conditions. Therefore water transfer through the MEA due to each mechanism could be measured separately. In this study, all the data were collected in an actual assembled operational fuel cell, and some of the data were collected while the fuel cell was generating power. The measured results showed that water transfer due to hydraulic permeation, i.e. the pressure difference between the anode and cathode is at least an order of magnitude lower than those due to other two mechanisms. The data for water transfers due to electro-osmosis and diffusion through the MEA are in good agreement with some of the data and model predications in the literature for the membrane. The methodology used in this study is simple and can be easily adopted for in-situ water transfer measurement due to different mechanisms in actual PEM fuel cells without any cell modifications.

Predicting the Effect of Gas-Flow Channel Spacing on Current Density in PEM Fuel Cells

1999 ◽  
Author(s):  
Hamid Naseri-Neshat ◽  
Sirivatch Shimpalee ◽  
Sandip Dutta ◽  
Woo-kum Lee ◽  
J. W. Van Zee
Keyword(s):  
Fuel Cell ◽  
Cross Sections ◽  
Diffusion Layer ◽  
Current Density ◽  
Gas Flow ◽  
Channel Model ◽  
Three Dimensional ◽  
Pem Fuel Cell ◽  
Flow Channel ◽  
Straight Channel

Abstract The effects of change in diffusion layer width for constant diffusion layer thickness and constant gas-flow channel width are investigated with a straight channel model of a Proton Exchange Membrane (PEM) fuel cell. A three-dimensional 10-cm long straight channel model of the PEM fuel cell is presented. The geometrical model includes diffusion layers on both the anode and cathode sides and the numerical model couples three-dimensional Navier-Stokes flow with electro-chemical reactions occurring in the fuel cell. Contours of the current density, anode water vapor concentration, anode water activity, water molecules per proton flux, and secondary flow velocity vectors at different cross sections are presented for the two diffusion layer widths. For the particular conditions and properties used for this study, the results show a marked difference between the base case (0.16-cm) and the wide (0.72-cm) diffusion layer. The current density is quite uniform at different axial cross sections and cross-flow sections for the 0.16-cm wide diffusion layer. However, for the 0.72-cm wide diffusion layer, the current density decreases more significantly in the axial direction near the edges of the diffusion layer. Numerical predictions of the water transport between cathode and anode across the width of the MEA show the delicate balance of diffusion and electro-osmosis and their effect on the current distribution along channel.

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