scholarly journals CFD Simulation and Performance Investigation on a Novel Bionic Spider-Web-Type Flow Field for PEM Fuel Cells

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1526
Author(s):  
Qizhen Xie ◽  
Minggang Zheng

The products generated by the electrochemical reaction in the PEM fuel cell (PEMFC) are mainly concentrated in the flow field on the cathode side of the bipolar plate, and the oxygen introduced on the cathode has higher requirements to improve its diffusion performance by using the flow field structure. For this reason, the optimization of the cathode flow field of the PEMFC is essential. Inspired by the structure of a spider web, this paper proposes a novel spider-web-type flow field. In this kind of flow field, the shape of a polygonal structure and the number of layers of spiral flow channels are the two most crucial variables. In order to explore the impact of these two variables on the cathode flow field, complete three-dimensional PEMFC models with different values of the two variables were established, and the models were simulated by the method of CFD. By observing the results of oxygen distribution, the water removal performance and fuel cell output performance of different schemes, the optimal scheme of the polygonal structure and layer number are determined. Compared with the traditional flow field, it is proved that the optimization scheme is desirable in improving the performance of the cathode flow field in PEMFC.

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3203 ◽  
Author(s):  
Oluwatosin Ijaodola ◽  
Emmanuel Ogungbemi ◽  
Fawwad Nisar. Khatib ◽  
Tabbi Wilberforce ◽  
Mohamad Ramadan ◽  
...  

Environmental concerns of greenhouse gases (GHG) effect from fossil commodities and the fast increase in global energy demand have created awareness on the need to replace fossil fuels with other sources of clean energy. PEM fuel cell (PEMFC) is a promising source of energy to replace fossil fuels. The commercialization of the cell depends on its price, weight and mechanical strength. Bipolar plates are among the main components of PEMFC which perform some significant functions in the fuel cell stack. Metal bipolar plate is considered by the research community as the future material for fuel cells. However, surface coating is required for metals to enhance its corrosion resistance, hydrophilicity and interfacial contact resistance (ICR) in PEM fuel cells. Open pore cellular metal foam (OPCMF) materials have been used to replace the conventional flow field channel in recent times due to its low electrical resistance, high specific area and high porosity; however, it endures the same corrosion problem as the metallic bipolar plate. This investigation offers an overview on different types of bipolar plates and techniques in coating metallic bipolar platse and open pore metal foam as flow field channel materials to improve the corrosion resistance which will eventually increase the efficiency of the fuel cell appreciably.


Author(s):  
S. Cano-Andrade ◽  
A. Herna´ndez-Guerrero ◽  
M. Von-Spakovsky ◽  
C. Rubio-Arana

Proton exchange membrane (PEM) fuel cells are promising candidates for power generation in transportation, portable, and stationary applications due to their high full and partload efficiencies, low operating temperatures, high power densities, fast startups, and potential system robustness. A vital component for this new technology is the bipolar plate since it supplies the fuel and oxidant, removes the products of reaction, collects the current produced, and provides mechanical support for the cells in the stack. However, the bipolar plate adds weight, volume, and cost to the fuel cell. A way to offset this, at least partially and perhaps significantly, would be by improving the bipolar plate flow field layout so that the power density of the cell or stack (parallel cell arrangement) is improved. To that end, this paper proposes an innovative radial flow field design for which a three-dimensional model of the heat, mass, and charge transport and electrochemistry in a single fuel cell has been developed and solved via a finite volume approach. This model is based on the following supposition: steady state, isothermal, single phase, isotropic materials and mass transfer in three directions. Predictions of current density as well as the pressure losses, velocities, and flow field contours are made and presented.


2016 ◽  
Vol 30 (16) ◽  
pp. 1650155 ◽  
Author(s):  
Ebrahim Afshari ◽  
Masoud Ziaei-Rad ◽  
Nabi Jahantigh

In PEM fuel cells, during electrochemical generation of electricity more than half of the chemical energy of hydrogen is converted to heat. This heat of reactions, if not exhausted properly, would impair the performance and durability of the cell. In general, large scale PEM fuel cells are cooled by liquid water that circulates through coolant flow channels formed in bipolar plates or in dedicated cooling plates. In this paper, a numerical method has been presented to study cooling and temperature distribution of a polymer membrane fuel cell stack. The heat flux on the cooling plate is variable. A three-dimensional model of fluid flow and heat transfer in cooling plates with 15 cm × 15 cm square area is considered and the performances of four different coolant flow field designs, parallel field and serpentine fields are compared in terms of maximum surface temperature, temperature uniformity and pressure drop characteristics. By comparing the results in two cases, the constant and variable heat flux, it is observed that applying constant heat flux instead of variable heat flux which is actually occurring in the fuel cells is not an accurate assumption. The numerical results indicated that the straight flow field model has temperature uniformity index and almost the same temperature difference with the serpentine models, while its pressure drop is less than all of the serpentine models. Another important advantage of this model is the much easier design and building than the spiral models.


2017 ◽  
Vol 41 (14) ◽  
pp. 2184-2193 ◽  
Author(s):  
Wen Dong-Hui ◽  
Yin Lin-Zhi ◽  
Piao Zhong-Yu ◽  
Lu Cong-Da ◽  
Li Gang ◽  
...  

Author(s):  
Tao Zhang ◽  
Pei-Wen Li ◽  
Qing-Ming Wang ◽  
Laura Schaefer ◽  
Minking K. Chyu

Two types of miniaturized PEM fuel cells are designed and characterized in comparison with a compact commercial fuel cell device in this paper. One has Nafion® membrane electrolyte sandwiched by two brass bipolar plates with micromachined meander-like gas channels. The cross-sectional area of the gas flow channel is approximately 250 by 250 (μm). The other uses the same Nafion® membrane and anode structure, but in stead of the brass plate, a thin stainless steel plate with perforated round holes is used at cathode side. The new cathode structure is expected to allow oxygen (air) being supplied by free-convection mass transfer. The characteristic curves of the fuel cell devices are measured. The activation loss and ohmic loss of the fuel cells have been estimated using empirical equations. Critical issues such as flow arrangement, water removing and air feeding modes concerning the fuel cell performance are investigated in this research. The experimental results demonstrate that the miniaturized fuel cell with free air convection mode is a simple and reliable way for fuel cell operation that could be employed in potential applications although the maximum achievable current density is less favorable due to limited mass transfer of oxygen (air). The relation between the fuel cell dimensions and the maximum achievable current density is also discussed with respect to free-convection mode of air feeding.


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