scholarly journals The Effects of the PEM Fuel Cell Performance with the Waved Flow Channels

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Yue-Tzu Yang ◽  
Kuo-Teng Tsai ◽  
Cha’o-Kuang Chen
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Gas Flow ◽  
Gas Diffusion ◽  
Flow Channel ◽  
Proton Exchange ◽  
Electrical Performance ◽  
Wave Number ◽  
Gap Size ◽  
Fuel Cell Performance

The objective of this study is to use a new style of waved flow channel instead of the plane surface channel in the proton exchange membrane fuel cell (PEMFC). The velocity, concentration, and electrical performance with the waved flow channel in PEMFC are investigated by numerical simulations. The results show that the waved channel arises when the transport benefits through the porous layer and improves the performance of the PEMFC. This is because the waved flow channel enhances the forced convection and causes the more reactant gas flow into the gas diffusion layer (GDL). The performance which was compared to a conventional straight gas flow channel increases significantly with the small gap size when it is smaller than 0.5 in the waved flow channel. The performance is decreased at the high and low velocities as the force convection mechanism is weakened and the reactant gas supply is insufficient. The pressure drop is increased as the gap size becomes smaller, and the wave number decreases. (gap size)δ> 0.3 has a reasonable pressure drop. Consequently, compared to a conventional PEMFC, the waved flow channel improves approximately 30% of power density.

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.

Effect of Gas Diffusion Layer Surface Wettability Gradient on Water Behavior in a Serpentine Gas Flow Channel of Proton Exchange Membrane Fuel Cell

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Sneha Malhotra ◽  
Sumana Ghosh
Keyword(s):  
Fuel Cell ◽  
Diffusion Layer ◽  
Gas Flow ◽  
Proton Exchange Membrane ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Flow Channel ◽  
Proton Exchange ◽  
Surface Wettability ◽  
Exchange Membrane

Water removal and behavior, in proton exchange membrane fuel cell (PEMFC) gas flow channel has been investigated in this work. Single serpentine gas flow channel has been simulated. Hydrodynamics of water drops in a serpentine channel are studied as a function of nature of gas diffusion layer (GDL) surface wettability. In one case, the surface becomes gradually hydrophobic starting from 90 deg to 170 deg. In this second case, the value of contact angle reduces to 10 deg. A three-dimensional model has been developed by using cfd software. Two different drop of diameter 0.2 mm and 0.4 mm are simulated for all the cases. It is observed that, water coverage is always lesser for a gradual hydrophobic surface. Also at low air velocity and gradual hydrophobic GDL surface results in lesser pressure drop as well as water coverage.

The Effect of Catalyst Coated Diffusion Media on PEM Fuel Cell Performance

2009 ◽  
Author(s):  
Derek W. Fultz ◽  
Po-Ya Abel Chuang
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Thermal Contact ◽  
Electrical Contact ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Hot Press ◽  
Fuel Cell Performance ◽  
Diffusion Media ◽  
A Cell

Two fuel cell architectures, differing only by the surfaces onto which the electrodes were applied, have been analyzed to determine the root causes of dissimilarities in performance. The basic proton exchange membrane fuel cell (PEMFC) is comprised of the proton transporting membrane, platinum-containing anode and cathode electrodes, porous carbon fiber gas diffusion media (GDM), and flow fields which deliver the reactant hydrogen and air flows. As no optimal cell design currently exists, there is a degree of latitude regarding component assembly and structure. Catalyst coated diffusion media (CCDM) refers to a cell architecture option where the electrode layers are coated on the GDM layers and then hot-pressed to the membrane. Catalyst coated membrane (CCM) refers to an architecture where the electrodes are transferred directly onto the membrane. A cell with CCDM architecture has tightly bonded interfaces throughout the assembly which can result in lower thermal and electrical contact resistances. Considering the fuel cell as a 1-D thermal system, the through-plane thermal resistance was observed to decrease by 5–10% when comparing CCDM to CCM architectures. This suggests the thermal contact resistance at the electrode interfaces was significantly reduced in the hot-press process. In addition, the electrical contact resistances between the electrode and GDM were observed to be significantly reduced with a CCDM architecture. This study shows that these effects, which have a potential to increase performance, can be attributed to the hot-press lamination process and use of CCDM architecture.

Numerical Simulation Applied to Study the Effects of Fractal Tree-Liked Network Channel Designs on PEMFC Performance

2012 ◽  
Vol 488-489 ◽  
pp. 1219-1223 ◽  
Author(s):  
Shan Jen Cheng ◽  
Jr Ming Miao ◽  
Chang Hsien Tai
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Flow Field ◽  
Fluid Dynamic ◽  
Flow Distribution ◽  
Flow Channel ◽  
Proton Exchange ◽  
Channel Network ◽  
Computational Fluid Dynamic Analysis ◽  
Network Channel

The effect of pressure drop and the flow-field of inhomogeneous transport of reactions gas are two important issues for bipolar flow channel design in proton exchange membrane fuel cell (PEMFC). A novel design through the imitation of biological development of the topology distribution of fractal tree-liked network channel is the main topic of this research. The effects of different Reynolds numbers and stoichiometric mass flow rate of reaction gas on the flow field distribution of tree-like channels were investigated by three-dimensional computational fluid dynamic analysis. According to numerical simulations, the fractal tree-liked network channel would have an excellent performance on the uniformity of multi-branching flow distribution and lower pressure drop along channels. The new type of fractal tree-liked bionic flow channel network design will be applied to assist in the experimental reference for improving the performance of fuel cell stack system in PEMFC for future.

Orientation-Dependent Performance of Portable Proton Exchange Membrane Fuel Cells

2011 ◽  
Vol 8 (3) ◽  
Author(s):  
Jen-Chieh Lee ◽  
Tony Shay ◽  
Song-Kuo Chang
Keyword(s):  
Fuel Cell ◽  
Gas Flow ◽  
Proton Exchange Membrane ◽  
Produced Water ◽  
High Current Density ◽  
Vertical Direction ◽  
Flow Channel ◽  
Proton Exchange ◽  
High Current ◽  
Channel Distribution

The effects of gravitational force on the orientation-dependent performance of portable proton exchange membrane (PEM) fuel cell using serpentine flow channels were investigated by the measurement and analysis of polarization curves. Whether the removal of produced water in the cathode flow channel is resisted or assisted by the gravity depends on the orientation variation, flow direction, and flow channel distribution of a fuel cell. This gravity will then affect the fuel cell performance, especially for fuel cells operating at a high current density. The results show that a fuel cell with perpendicular flow channel distribution and cathode gas flow in vertical direction requires a longer distance of pushing liquid droplets against gravity to remove the produced water, which is difficult to expel the produced water from the flow channels, and the performance reduction is obviously in high current density. A fuel cell operating in a normal position achieves higher performance than one operating in a horizontal position, except the cathode gas flow in vertical direction and feed from lower inlet. Furthermore, for a fuel cell operating in a horizontal position with anode below the membrane, gravitational force transports the water to the anode and blocks the fuel channel in the gas diffusion layer. This leads a fuel cell operating in high current densities with the cathode below the membrane performs better than one with the cathode above the membrane. Therefore, to reduce the effects of gravity on the orientation-dependent performance, a fuel cell with parallel flow channel distribution and feeding the cathode gas from the upper inlet port is recommended in this study.

scholarly journals Numerical Investigation Of Thermodiffusion Effects On PEM Fuel Cell Performance

2021 ◽  
Author(s):  
Rihab. Jaralla
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Finite Thickness ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Operating Pressure ◽  
Fuel Cell Performance ◽  
Catalyst Layers ◽  
Diffusion Layers

A novel mathematical model for an entire proton exchange membrane fuel cell (PEMFC) is developed with its focus placed on the modeling and assessment of thermodiffusion effects that have been neglected in previous studies. Instead of treating catalyst layers as interfaces of nil thickness, the model presented here features a finite thickness employed for catalyst layers, allowing for a more realistic description of electrochemical reaction kinetics arising in the operational PEMFC. To account for the membrane swelling effect, the membrane water balance is modeled by coupling the diffusion of water, the pressure variation, and the electro-osmotic drag. The complete model consisting of the equations of continuity, momentum, energy, species concentrations, and electric potentials in different regions of a PEMFC are numerically solved using the finite element method implemented into a commercial CFD (Comsol 3.4) code. Various flow and transport phenomena in an operational PEMFC are simulated using the newly developed model. The resulting numerical simulations demonstrate that the thermodiffusion has a noticeable impact on the mass transfer for the oxygen. It is also revealed through a systematic parametric study that, as the porosity of gas diffusion layers and catalyst layers increase, the current density of an operational PEMFC may increase. Also, it is found that a PEM fuel cell can perform better with reasonable high operating pressure and temperature, as well as a supply of fully humidified gaseous reactants.

Enhancement of proton exchange membrane fuel cell performance by titanium-coated anode gas diffusion layer

2014 ◽  
Vol 39 (36) ◽  
pp. 21177-21184 ◽  
Author(s):  
Sheng-Yu Fang ◽  
Lay Gaik Teoh ◽  
Rong-Hsin Huang ◽  
Kan-Lin Hsueh ◽  
Ko-Ho Yang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Diffusion Layer ◽  
Proton Exchange Membrane ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Cell Performance ◽  
Fuel Cell Performance ◽  
Exchange Membrane
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