scholarly journals Effect of Friction Coefficient on Relative Slippage of Fuel Cell Stack under Mechanical Impact Condition

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Yongping Hou ◽  
Leiqi Wang ◽  
Jianwen Zhang ◽  
Dong Hao
Keyword(s):  
Fuel Cell ◽  
Friction Coefficient ◽  
Three Dimensional ◽  
Element Model ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Membrane Electrode ◽  
Three Dimensional Model ◽  
Impact Acceleration ◽  
Relative Slippage

A simplified finite element model for large polymer electrolyte membrane fuel cell (PEMFC) stack consisting of ten cells is established in order to investigate the internal structure deformation. It is found that the interface slippage occurs when the bipolar plate (BP) and membrane electrode assembly (MEA) are subjected to vertical impact acceleration. Based on this three-dimensional model, the influence of the friction coefficient between BP and MEA on the relative slippage can be analyzed efficiently. The division layer of relative slippage is found and its vibration rule is discussed. It is observed that increasing the magnitude of impact vibration has most significant effect on the movement of the division layer, and the two variables are linearly related when impact acceleration is greater than 5 g. This work provides important insight into the choice of the friction coefficient.

Improving the Performance of a PEMFC by Means of Achieving Uniform Flow Distribution

2010 ◽  
Author(s):  
Bladimir Ramos-Alvarado ◽  
Abel Hernandez-Guerrero ◽  
Francisco Elizalde-Blancas ◽  
Cuauhtemoc Rubio-Arana
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Membrane Electrode Assembly ◽  
Flow Patterns ◽  
Proton Exchange ◽  
Membrane Electrode ◽  
Channel Configuration

A performance analysis of a proton exchange membrane fuel cell is reported in this work. Two different flow patterns are modeled as gas distributors and current collectors of a PEM fuel cell. Both flow patterns have the same active area with similar channel distribution over the membrane electrode assembly. Three dimensional models are used in order to simulate the performance of the fuel cells. The Navier-Stokes equations as well as potential fields (potentiostatic and galvanostatic) are solved using computational fluid dynamics techniques. Two dimensionless parameters were computed to quantify and compare the uniformity of the flow over the reaction area. The present analysis shows that achieving a good flow distribution is a key parameter in the PEMFC performance. The reduction of the concentration losses is the main result when a parallel channel configuration operates with uniform reactants distribution. In this study is demonstrated that the conventional parallel channels flow pattern does not achieve similar flow conditions in each sub-stream and therefore, irregular energy generation is obtained.

A Simple Thermal Model of PEM Fuel Cell Stacks

2004 ◽  
Author(s):  
B. Wetton ◽  
K. Promislow ◽  
A. C¸ag˘lar
Keyword(s):  
Fuel Cell ◽  
Temperature Distribution ◽  
Thermal Transport ◽  
Thermal Model ◽  
Cell Voltage ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Membrane Resistance ◽  
Coolant Temperature ◽  
Membrane Electrode

A simple model is developed that determines the temperature distribution through a unit fuel cell with straight flow channels, in steady state operation. Using the large aspect ratio of the typical fuel cell geometry, the thermal model approximately decouples cross-plane thermal transport at each channel location. Using the fact that in-plane thermal conductivities are much larger than through-plane in typical bipolar plate construction, it is possible to further approximate the cross-plane thermal transport with a simple, one-dimensional model. We then consider the thermal coupling of several unit cells connected in series. In this way, we can simulate the effect of an anomalously hot cell in a stack environment. We take as inputs to the model the cell voltage and local current density, membrane resistance and condensation rates from a previously developed model. The thermal model outputs the average coolant temperature and the temperature distribution through the bipolar plates and membrane electrode assembly at each location down the channel. Although we are aware that there are significant coupling effects between the thermal distribution and performance, this is not taken into account in this study.

Effect of Channel Depth and Cell Temperature on the Performance of a Direct Methanol Fuel Cell

2013 ◽  
Vol 10 (3) ◽  
Author(s):  
Ebrahim Alizadeh ◽  
Mousa Farhadi ◽  
Kurosh Sedighi ◽  
Mohsen Shakeri
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Channel Depth ◽  
Direct Methanol ◽  
Pt Black ◽  
Methanol Fuel Cell

The main goal of this study is to analyze the performance of the direct methanol single cell using three channel depths at various cell temperatures. The membrane electrode assembly (MEA) used Nafion® 117, by loading a Pt-Ru (4 mg/cm2) catalyst at the anode and Pt-black (4 mg/cm2) catalyst at the cathode. The active area of the MEA was 100 cm (Jung et al., 2009, “Investigation of Flow Bed Design in Direct Methanol Fuel Cell,” J. Solid State Electrochem., 13, pp. 1455–1465). In these sets of experiments, anode and cathode channel depth were varied simultaneously. The cell performance is improved with an increase of temperature in a certain range because the conductivity of the membrane and the reaction kinetics at both the anode and cathode are increased. Also, when the channel depth of the bipolar plate is decreased from 2.0 to 1.0 mm, the cell performance increases. The decreased channel depth leads to an increase in the linear velocity of reactants and products.

Visualization and understanding of the degradation behaviors of a PEFC Pt/C cathode electrocatalyst using a multi-analysis system combining time-resolved quick XAFS, three-dimensional XAFS-CT, and same-view nano-XAFS/STEM-EDS techniques

2020 ◽  
Vol 22 (34) ◽  
pp. 18919-18931
Author(s):  
Kotaro Higashi ◽  
Shinobu Takao ◽  
Gabor Samjeské ◽  
Hirosuke Matsui ◽  
Mizuki Tada ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Three Dimensional ◽  
Membrane Electrode Assembly ◽  
Polymer Electrolyte Fuel Cell ◽  
Membrane Electrode ◽  
Time Resolved ◽  
Degradation Behaviors ◽  
Analysis System

We developed a multi-analysis system that can measure in situ time-resolved quick XAFS and in situ three-dimensional XAFS-CT in the same area of a cathode electrocatalyst layer in a membrane-electrode assembly of a polymer electrolyte fuel cell.

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.

Electrically Conductive CNT/PTFE Composite Film for Corrosion Resistant Coating on Bipolar Plate of Fuel Cell

2009 ◽  
Vol 1204 ◽  
Author(s):  
Yoshiyuki Show ◽  
K. Takahashi ◽  
R. Nishimura ◽  
K. Kohara ◽  
Y. Fukami ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Composite Film ◽  
Polymer Electrolyte Membrane ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Membrane Electrode ◽  
Electrically Conductive ◽  
Corrosion Resistant ◽  
Electrolyte Membrane ◽  
Conductive Film

AbstractComposite film of carbon nanotube (CNT) and polytetrafluoroethylene (PTFE) was formed with despersion fluid of CNT and PTFE. The film showed high electrical conductivity in the range of 5-13S/cm. This conductive film was applied on the stainless steel bipolar plate for the polymer electrolyte membrane fuel cell (PEMFC) as anticorrosion film. This coating decreased the contact resistance between the surface of bipolar plate and the membrane electrode assembly (MEA) of the PEMFC. Therefore, the output power of the fuel cell was increased by 1.6 times.

Research of Special-Shaped Membrane Electrode Assembly for Direct Methanol Fuel Cell

2011 ◽  
Vol 464 ◽  
pp. 409-413 ◽  
Author(s):  
Xing Xing Wang ◽  
Hong Jun Ni ◽  
Yu Zhu ◽  
Ming Yu Huang ◽  
Ping Liao
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Catalyst Layer ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Cathode Layer ◽  
Membrane Electrode ◽  
Titanium Mesh ◽  
Three Dimensional Model

In order to reduce the costs, improve the performances and promote the industry process, basing on calculus and finite element thinking, conceptual design of special-shaped membrane electrode assembly (S-MEA) was proposed, including six shapes. S-MEA size was determined by calculating, admeasuring and devising elaborately, whose basic parameter was gained from experiment datum. S-MEA was made up of titanium mesh anode layer, anode catalyst layer, Nafion membrane layer, cathode catalyst layer, gas diffusion layer and titanium mesh cathode layer in turn, which was different from MEA of the fluid field bipolar plates in the macro-structure but had the same micro-mechanism. Three-dimensional model was devised through Pro/E, planar diagrammatic drawing was created by the software also, and detail drawing was designed further with CAD. The process of preparing S-MEA was researched basing on the design. Then three typical S-MEA prototypes were made by bend-hot-pressing with home-made molds and precision hydraulic machine, including open triangular cross-section MEA, circular cross-section MEA and square cross-section MEA.

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