Development and Experimental Validation of a Simulation Tool for a Fuel Cell Based Power System

Volume 1 ◽  
2004 ◽  
Author(s):  
Luca Andreassi ◽  
Stefano Cordiner ◽  
Massimo Feola ◽  
Fabio Romanelli
Keyword(s):  
Experimental Data ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Numerical Models ◽  
Critical Issue ◽  
Proton Exchange ◽  
Design Parameters ◽  
Operating Pressure ◽  
Research Activity ◽  
Set Up

Fuel cells (FC) technology applied to energy production could represent an effective solution to face greenhouse gas emissions and to differentiate energy sources. However, real performances of FC systems still represent a critical issue in the definition of an assessed and economically competitive technology. In fact, FC performances depend on many variables such as temperature, pressure, current, membrane humidification, stoichiometry of the reactant gas, etc.; additionally, many of these influencing parameters depend one on the other, further complicating the analysis. Numerical simulation could greatly contribute to a better understanding of the influence of design parameters. Nevertheless, the availability of experimental data to validate and to verify the numerical models is an imperative issue. The primary target of the research activity described in this paper is the set up of an experimental test bench for Proton Exchange Membrane Fuel Cell (PEM FC) at the Department of Mechanical Engineer of the University of Roma Tor Vergata aiming to completely test 8 cells 0.1 kW stack: the measured data are fundamental to validate the numerical models which have been developed by the Authors following different hierarchical levels (both semi-empirical and dimensional analytical approach) with different predictive capabilities. This apparatus allows the control of the reactant gas mass flow rates, stack pressure, humidity, current, temperature and voltage. In this way it is possible to assess a mixed experimental-numerical methodology allowing a tuning procedure for the developed models making a wide use of dedicated experimental data. The preliminary results in terms of comparisons between experimental and computational data show a good agreement even by varying some of the most performance-affecting parameters such as operating pressure and temperature.

An Experimental Study of Operational Parameters on the Performance of PEMFCs

2010 ◽  
Author(s):  
Emad G. Barakat ◽  
Ali K. Abdel-Rahman ◽  
Mahmoud A. Ahmed ◽  
Ahmed Hamza H. Ali
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Pressure ◽  
Operational Parameters ◽  
Cell Temperature ◽  
Power Increase ◽  
Set Up ◽  
Exchange Membrane ◽  
Gas Humidification

The performance of Proton exchange membrane fuel cell (PEMFC) has been experimentally investigated. An experimental set-up was designed to study the effects of operating parameters such as cell temperature, gas humidification, and cell operating pressure on the performance of fuel cell. The results indicated that the output power increase with the increase of humidification ratio. Furthermore, an increase of cell pressure results in a significant increase of cell power. The results indicated that increasing of the temperature leads to a decrease of cell power. The results are explained and discussed in more details for different operational parameters.

CFD Investigation of a PEMFC Stack Assembly

2019 ◽  
Author(s):  
Kevin R. Anderson ◽  
Andrew Murphy
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Pt Catalyst ◽  
Cfd Modeling ◽  
Software Module ◽  
Contour Plots ◽  
Set Up ◽  
Voltage Performance ◽  
Exchange Membrane

Abstract In this study 3-D CFD modeling of a cylindrical stack Proton-exchange membrane fuel cell (PEMFC) is provided. The H2O-O2 PEMFC uses a 10.8 mm2 area membrane and Platinum (Pt) catalyst. The paper presents the methodology for the PEMFC commercial software module, the set-up of the Computational Fluid Dynamics (CFD) geometry, mesh and boundary conditions. Results for the current-voltage performance curves and 3-D contour plots of the fluid, heat and species concentrations within the PEMFC are given. Results are presented for a low-temperature fuel cell using NAFION membrane and a high-temperature fuel cell using BZY membrane.

Nonlinear Analysis of Two-Phase Instabilities in PEMFC Parallel-Channel Cathodes

2010 ◽  
Author(s):  
Nicholas Siefert ◽  
Chi-Hsin Ho ◽  
Shawn Litster
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Liquid Water ◽  
Proton Exchange Membrane ◽  
Critical Issue ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Stoichiometric Ratio ◽  
Two Phase ◽  
Voltage Loss

Liquid water management is a critical issue in the development of proton exchange membrane (PEM) fuel cells. Liquid water produced electrochemically can accumulate and flood the microchannels in the cathodes of PEM fuel cells. Since the liquid coverage of the cathode can fluctuate in time for two-phase flow, the rate of oxygen transport to the cathode catalyst layer can also fluctuate in time, and this can cause the fuel cell power output to fluctuate. This paper will report experimental data on the voltage loss and the voltage fluctuations of a PEM fuel cell due to flooding as a function of the number of parallel microchannels and the air flow rate stoichiometric ratio. The data was analyzed to identify general scaling relationships between voltage loss and fluctuations and the number of channels in parallel and the air stoichiometric ratio. The voltage loss was found to scale proportionally to the square root of the number of channels divided by the air stoichiometric ratio. The amplitude of the fluctuations was found to be linearly proportional to the number of microchannels and inversely proportional to the air stoichiometric ratio squared. The data was further analyzed by plotting power spectrums and by evaluating the non-linear statistics of the voltage time-series.

Molecular Dynamics Simulation of Water Behavior as a Function of Temperatures and Monomer Numbers in Nafion 117

2007 ◽  
Author(s):  
Kyung Su Oh ◽  
Seungho Park ◽  
Ohmyoung Kwon ◽  
Young Ki Choi ◽  
Joon Sik Lee
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Molecular Model ◽  
Critical Role ◽  
Proton Exchange ◽  
Dynamics Simulation ◽  
Sulfonate Group ◽  
Efficient Operation ◽  
Self Diffusion ◽  
Set Up

The proton exchange membrane plays a critical role as an electrolyte for proton transports in the PEMFC. Generally, the membrane, such as Nafion 117, consists of a polytetrafluoro-ethylene (PTFE) backbone and side-chains terminated with a sulfonate group (SO3−). Operating the fuel cell, the membrane preferentially becomes hydrated by absorbing water. Then, the hydrogen atom on the SO3− part of the side-chain can detach from its own position and hop to the next SO3− site. The water management is the key to the efficient operation of the fuel cell, since the water content is the one of decisive factors for membrane’s lifetime and efficient operations of fuel cells as well. In this report, we set up the molecular model for hydrated Nafion 117 and simulate the molecular movements for various temperatures and monomer numbers. Here, we obtain the mean square displacements of water molecules and estimate the self-diffusion coefficients of water in the Nafion 117.

Optimization of the Operating Parameters of a Proton Exchange Membrane Fuel Cell for Maximum Power Density

2005 ◽  
Vol 2 (2) ◽  
pp. 121-135 ◽  
Author(s):  
A. Mawardi ◽  
F. Yang ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Power Density ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Design Parameters ◽  
Membrane Thickness ◽  
Exchange Membrane

The performance of fuel cells can be significantly improved by using optimum operating conditions that maximize the power density subject to constraints. Despite its significance, relatively scant work is reported in the open literature on the model-assisted optimization of fuel cells. In this paper, a methodology for model-based optimization is presented by considering a one-dimensional nonisothermal description of a fuel cell operating on reformate feed. The numerical model is coupled with a continuous search simulated annealing optimization scheme to determine the optimum solutions for selected process constraints. Optimization results are presented over a range of fuel cell design parameters to assess the effects of membrane thickness, electrode thickness, constraint values, and CO concentration on the optimum operating conditions.

scholarly journals Interfacial Water Transport Effects in Proton-Exchange Membranes

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Brian Kientiz ◽  
Haruhiko Yamada ◽  
Nobuaki Nonoyama ◽  
Adam Z. Weber
Keyword(s):  
Experimental Data ◽  
Fuel Cell ◽  
Water Transport ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Polymer Electrolyte Fuel Cell ◽  
Interfacial Resistance ◽  
Fuel Cell Performance ◽  
Membrane Interfaces

It is well known that the proton-exchange membrane is perhaps the most critical component of a polymer-electrolyte fuel cell. Typical membranes, such as Nafion®, require hydration to conduct efficiently and are instrumental in cell water management. Recently, evidence has been shown that these membranes might have different interfacial morphology and transport properties than in bulk. In this paper, experimental data combined with theoretical simulations that explore the existence and impact of interfacial resistance on water transport for Nafion®21x membranes will be presented. A mass-transfer coefficient for the interfacial resistance is calculated from experimental data using different permeation cells. This coefficient is shown to depend exponentially on relative humidity or water activity. The interfacial resistance does not seem to exist for liquid/membrane or membrane/membrane interfaces. The effect of the interfacial resistance is to flatten the water content profiles within the membrane during operation. Under typical operating conditions, the resistance is on par with the water transport resistance of the bulk membrane. Thus, the interfacial resistance can be dominant especially in thin, dry membranes and can affect overall fuel cell performance.

A Numerical Simulation of Proton Exchange Membrane Fuel Cell Performance

2011 ◽  
Vol 347-353 ◽  
pp. 376-385
Author(s):  
Shi Gang Yu ◽  
Hui He ◽  
You Sheng Xu
Keyword(s):  
Numerical Simulation ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Flow Direction ◽  
Proton Exchange ◽  
Cell Performance ◽  
Cathode Side ◽  
Operating Pressure ◽  
Fuel Cell Performance ◽  
Exchange Membrane

A composite three-dimensional mathematical model of proton exchange membrane fuel cell is proposed, the corresponding finite element method and numerical simulation are given as well, where fluid flow, proton transport, and electrochemical reaction are addressed. Some factors that probably affect the performance of the cell are analyzed by using the model. The computational results show that the reactant concentration decreases along the flow direction, the water concentration increases in the cathode side of membrane, membrane resistance decreases, conductivity increases and proton concentration increases. The fuel cell performance is better when the porosity increases, as well as the operating pressure.

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.

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