Multiphysics Modeling of Assembly Pressure Effects on Proton Exchange Membrane Fuel Cell Performance

Author(s):  
Y. Zhou ◽  
G. Lin ◽  
A. J. Shih ◽  
S. J. Hu

The clamping pressure used in assembling a proton exchange membrane (PEM) fuel cell stack can have significant effects on the overall cell performance. The pressure causes stack deformation, particularly in the gas diffusion layer (GDL), and impacts gas mass transfer and electrical contact resistance. Existing research for analyzing the assembly pressure effects is mostly experimental. This paper develops a sequential approach to study the pressure effects by combining the mechanical and electrochemical phenomena in fuel cells. The model integrates gas mass transfer analysis based on the deformed GDL geometry and modified parameters with the microscale electrical contact resistance analysis. The modeling results reveal that higher assembly pressure increases cell resistance to gas mass transfer, causes an uneven current density distribution, and reduces electrical contact resistance. These combined effects show that as the assembly pressure increases, the PEM fuel cell power output increases first to a maximum and then decreases over a wide range of pressures. An optimum assembly pressure is observed. The model is validated against published experimental data with good agreements. This study provides a basis for determining the assembly pressure required for optimizing PEM fuel cell performance.

Author(s):  
Y. Zhou ◽  
G. Lin ◽  
A. J. Shih ◽  
S. J. Hu

Proton exchange membrane (PEM) fuel cells are favored in many applications due to their simplicity and relatively high power density. However, there has been a lack of understandings of the fundamental mechanisms of assembly and manufacturing induced phenomena and their influence on performance and durability. This paper presents a comprehensive analysis of assembly pressure induced phenomena in PEM fuel cells using multi-physics based modeling. A finite-element-based structural and mass-transfer model was developed by integrating mechanical deformation, mass transfer resistance, and electrical contact resistance to study the effects of assembly pressure and the fuel cell overall performance. Contact resistance, inhomogeneous deformation of membrane and GDL, electrochemical analysis were simulated. The fuel cell performance was predicted and an optimal assembly pressure was identified through this multi-physics model. Results show that PEM fuel cell performance first increases gradually to a maximum and then decreases with further assembly pressure increase. The influence of temperature and humidity on cell performance was also investigated.


Author(s):  
M. Minutillo ◽  
E. Jannelli ◽  
F. Tunzio

The main objective of this study is to evaluate the performance of a proton exchange membrane (PEM) fuel cell generator operating for residential applications. The fuel cell performance has been evaluated using the test bed of the University of Cassino. The experimental activity has been focused to evaluate the performance in different operating conditions: stack temperature, feeding mode, and fuel composition. In order to use PEM fuel cell technology on a large scale, for an electric power distributed generation, it could be necessary to feed fuel cells with conventional fuel, such as natural gas, to generate hydrogen in situ because currently the infrastructure for the distribution of hydrogen is almost nonexistent. Therefore, the fuel cell performance has been evaluated both using pure hydrogen and reformate gas produced by a natural gas reforming system.


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.


Energy ◽  
2008 ◽  
Vol 33 (12) ◽  
pp. 1794-1800 ◽  
Author(s):  
Jarupuk Thepkaew ◽  
Apichai Therdthianwong ◽  
Supaporn Therdthianwong

Author(s):  
J. P. Owejan ◽  
T. A. Trabold ◽  
D. L. Jacobson ◽  
M. Arif ◽  
S. G. Kandlikar

Water is the main product of the electrochemical reaction in a proton exchange membrane (PEM) fuel cell. Where the water is produced over the active area of the cell, and how it accumulates within the flow fields and gas diffusion layers, strongly affects the performance of the device and influences operational considerations such as freeze and durability. In this work, the neutron radiography method was used to obtain two-dimensional distributions of liquid water in operating 50 cm2 fuel cells. Variations were made of flow field channel and diffusion media properties, to assess the effects on the overall volume and spatial distribution of accumulated water. Flow field channels with hydrophobic coating retain more water, but the distribution of a greater number of smaller slugs in the channel area improves fuel cell performance at high current density. Channels with triangular geometry retain less water than rectangular channels of the same cross-sectional area, and the water is mostly trapped in the two corners adjacent to the diffusion media. Also, it was found that cells constructed using diffusion media with lower in-plane gas permeability tended to retain less water. In some cases, large differences in fuel cell performance were observed with very small changes in accumulated water volume, suggesting that flooding within the electrode layer or at the electrode-diffusion media interface is the primary cause of the significant mass transport voltage loss.


2010 ◽  
Vol 447-448 ◽  
pp. 559-563 ◽  
Author(s):  
Misran Erni ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan

Flow field design has several functions that should perform simultaneously. Therefore, specific plate materials and channel designs are needed to enhance the performance of proton exchange membrane (PEM) fuel cell. Serpentine flow field design is one of the most popular channel configurations for PEM fuel cell system. Some configurations have been developed to improve the cell performance. This paper presents a review on serpentine flow field (SFF) design and its influence to PEM fuel cell performance based on some indicators of performance. The comparisons of SFF with other flow field designs are summarized. The results of some experimental and numerical investigations are also presented.


2018 ◽  
Vol 156 ◽  
pp. 03033 ◽  
Author(s):  
Mulyazmi ◽  
W.R W Daud ◽  
Silvi Octavia ◽  
Maria Ulfah

Design of the Proton Exchange Membrane (PEM) fuel cell system is still developed and improved to achieve performance and efficiency optimal. Improvement of PEM fuel cell performance can be achieved by knowing the effect of system parameters based on thermodynamics on voltage and current density. Many parameters affect the performance of PEM fuel cell, one of which is the relative humidity of the reactants that flow in on the anode and cathode sides. The results of this study show that the increase in relative humidity value on the cathode side (RHC) causes a significant increase in current density value when compared to the increase of relative humidity value on the anode side (RHA). The performance of single cells with high values is found in RHC is from 70% to 90%. The maximum current density generated at RHA is 70% and RHC is 90% with PEM operating temperature of 363 K and pressure of 1 atm


2014 ◽  
Vol 11 (4) ◽  
Author(s):  
Guo Li ◽  
Jinzhu Tan ◽  
Jianming Gong ◽  
Xiaowei Zhang ◽  
Yanchao Xin ◽  
...  

Proton exchange membrane (PEM) fuel cell is regarded as one of the potential renewable energy which may provide a possible long-term solution to reduce carbon dioxide emissions, reduce fossil fuel dependency and increase energy efficiency. Even though great progress has been made, long-term stability and durability is still an issue. The contamination ion plays an important role on the electrical performance of PEM fuel cell. This paper investigates the effect of Mg2+ contamination on PEM fuel cell performance as a function of Mg2+ concentration. Two levels of Mg2+ concentration was chose. From the experimental results, it can be obtained that a significant drop in fuel cell performance occurred when Mg2+ was injected into the anode fuel stream. The voltage and power density of fuel cell decreased larger and larger with increase of Mg2+ concentration over time. The Mg2+ mainly caused the concentration polarization loss from the anode catalyst to the membrane in fuel cell.


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