Numerical Modeling of Proton Exchange Membrane Fuel Cell With Considering Thermal and Relative Humidity Effects on the Cell Performance

2006 ◽  
Vol 3 (3) ◽  
pp. 292-302 ◽  
Author(s):  
Pei-Hung Chi ◽  
Fang-Bor Weng ◽  
Ay Su ◽  
Shih-Hung Chan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuel Cell ◽  
Relative Humidity ◽  
Proton Exchange Membrane ◽  
Thermal Field ◽  
Proton Exchange ◽  
Cell Performance ◽  
Water Flooding ◽  
Exchange Membrane

A three-dimensional (3D) model has been developed to simulate proton exchange membrane fuel cells. The model accounts simultaneously for electrochemical kinetics, current distribution, hydrodynamics, and multi-components transport. A single set of conservation equations of mass, momentum, energy, species, and electric current are developed and numerically solved using a finite-volume-based computational fluid dynamics technique (by computational fluid dynamics ACE+ commercial code). The physical model is presented for a 5cm×4.92cm×0.4479cm 3D geometry test cell with serpentine channels and counter flow. Subsequently, the model is applied to explore cell temperature effects in the cell environment with different relative humidity of inlet. The numerical model is validated and agreed well with the experimental data. The nonuniformity of thermal and water-saturation distributions is calculated and analyzed as well as its influence on the cell performance. As the cell is operated at low voltages (or high current densities), the thermal field of fuel cell tends to be nonuniform and exists locally in hot spots. The mechanism of thermal field and water content interacted with membrane dehydration and cathode water flooding will be discussed and revealed their influences on the cell performance, stability and degradation will be revealed.

Study of a Pseudo Bipolar Design for a Piezoelectric Proton Exchange Membrane Fuel Cell With Nozzle and Diffuser

2010 ◽  
Author(s):  
Hsiao-Kang Ma ◽  
Jyun-Sheng Wang ◽  
Ya-Ting Chang
Keyword(s):  
Fuel Cell ◽  
Flow Rate ◽  
Proton Exchange Membrane ◽  
Produced Water ◽  
Three Dimensional ◽  
Proton Exchange ◽  
Cell Performance ◽  
Water Flooding ◽  
Geometrical Parameters ◽  
Exchange Membrane

Previous studies of a piezoelectric proton exchange membrane fuel cell with nozzle and diffuser (PZT-PEMFC-ND) have shown that a PZT device could solve flooding problems and improve cell performance. The results also indicated that the rectification efficiency (γ) of the diffuser elements, the PZT vibrating frequency (f), and the displaced volume per stroke (ΔV) affected the flow rate of the PZT device. The rectification efficiency of the diffuser elements, which is an indicator of the preferential direction, depends on the geometrical parameters (AR and θ) and the Reynolds number. In this study, an innovative design for a PZT-PEMFC-ND bi-cell with pseudo bipolar electrodes was developed to achieve a higher power in the stack design to solve water flooding problems and improve cell performance. This new design, with a reaction area of 8 cm2, contains two cells with two outside anodes and two inside cathodes that share a common PZT vibrating device for pumping air flow. The influence of the varying aspect ratio (AR) of the diffuser elements on the unit cell flow rate were investigated using a three-dimensional transitional model. The results show that a proper AR value of 11.25 for the diffuser with a smaller θ of 5° could ensure a smoother intake of the air and thus better cell performance. A lower AR value of 5.63 resulted in smaller actuation pressure inside the chamber, and thus the produced water could not be pumped out. However, a larger AR of 16.88 induced a blocking phenomenon inside the diffuser element, and thus less air was sucked into the cathode chamber. The performance of the PZT-PEMFC-ND bi-cell could be 1.6 times greater than that of the single cell. This performance may be influenced by the phase difference of the operating modes.

scholarly journals Three-dimensional multiphase flow computational fluid dynamics models for proton exchange membrane fuel cell: A theoretical development

2017 ◽  
Vol 9 (1) ◽  
pp. 3-25 ◽  
Author(s):  
Jean-Paul Kone ◽  
Xinyu Zhang ◽  
Yuying Yan ◽  
Guilin Hu ◽  
Goodarz Ahmadi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuel Cell ◽  
Multiphase Flow ◽  
Proton Exchange Membrane ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Proton Exchange ◽  
Dynamics Models ◽  
Exchange Membrane

A review of published three-dimensional, computational fluid dynamics models for proton exchange membrane fuel cells that accounts for multiphase flow is presented. The models can be categorized as models for transport phenomena, geometry or operating condition effects, and thermal effects. The influences of heat and water management on the fuel cell performance have been repeatedly addressed, and these still remain two central issues in proton exchange membrane fuel cell technology. The strengths and weaknesses of the models, the modelling assumptions, and the model validation are discussed. The salient numerical features of the models are examined, and an overview of the most commonly used computational fluid dynamic codes for the numerical modelling of proton exchange membrane fuel cells is given. Comprehensive three-dimensional multiphase flow computational fluid dynamic models accounting for the major transport phenomena inside a complete cell have been developed. However, it has been noted that more research is required to develop models that include among other things, the detailed composition and structure of the catalyst layers, the effects of water droplets movement in the gas flow channels, the consideration of phase change in both the anode and the cathode sides of the fuel cell, and dissolved water transport.

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