Numerical Modeling and Evaluation of PEM Used for Fuel Cell Vehicles (original) (raw)
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Asia-Pacific Journal of Chemical Engineering, 2009
Abstract The aim of this paper is to present a simple 3D computational model of a polymer electrolyte membrane fuel cell (PEMFC) that simulates over time the heat distribution, energy, and mass balance of the reactant gas flows in the fuel cell including pressure drop, humidity, and liquid water. Although this theoretical model can be adapted to any type of PEMFC, for verification of the model and to present different analysis it has been adapted to a single cell test fixture. The model parameters were adjusted through a series of ...
Thermodynamic Study of Operation Properties Effect on Polymer Electrolyte Membrane Fuel Cells (PEM)
2021
The thermodynamic analysis of PEM fuel cell energy production depends on the entropy and enthalpy of reaction with the changing of the operating temperatures that ranges between 50 and 100ºC, the electrical work done will be equal to the Gibbs free energy released. This paper presents a mathematical model of PEM fuel cells, based on physical-chemical procedures of the phenomena occurring inside the fuel cell, and it was theoretically studied the performance at different operation variables and conditions. The C++ program is designed to calculate all thermo-chemical parameters, i.e. enthalpy of formation, Gibbs free energy, work and efficiency for any type of fuel cells. The results are plotted as a function of fuel cell operating temperature. The results shows that the highest value of Gibbs energy is at the lowest operating temperature, and decreases gradually with increasing the temperature, the output voltage is determined by cell’s reversible voltage that arises from potential d...
Renewable and Sustainable Energy Reviews, 2019
Polymeric Electrolyte Membrane Fuel Cell (PEMFC) modeling considering thermal and electrical behavior in a coupled manner is a key aspect when evaluating new designs, materials, physical phenomena or control strategies. Depending on the behavior to be emulated, it is important to choose the modeling technique that best suits the needs required. In this sense, this paper describes the most commonly used PEMFC modeling techniques in the context of analytical-mechanistic approach, semi-empirical approach based on theoretical formulation and empirical correlations, as well as empirical approach based on experimentation with a real system. In addition, an in-depth analysis of PEMFC models at the cell and stack level that emulate the thermal and electrical behavior of these systems in a coupled manner is carried out. A chronological classification of the most relevant models has been made based on the modeling technique used, purpose of the model, state and dimension of the model, and the real system, other developed models or experimental results that have been used to validate the proposed new model. Additionally, guidelines to improve the energy efficiency of PEMFC systems through the development of new models are given.
SIMULATION OF UNIT CELL PERFORMANCE IN THE POLYMER ELECTROLYTE MEMBRANE FUEL CELL
− Fuel cells are devices that convert chemical energy directly into electrical energy. Owing to the high efficiency of the Fuel cells, a large number of research work have been done during this years. Among many kinds of the fuel cell, polymer electrolyte membrane fuel cell is such kind of thing which work under low temperature. Because of the speciality, it stimulated intense global R&D competition. Most of the major world automakers are racing to develop polymer electrolyte membrane fuel cell passenger vehicles. Unfortunately, there are still many problems to be solved in order to make them into commercial use, such as the thermal and water management in working process of polymer electrolyte membrane fuel cell. To solve the difficulites facing the researcher, the analysis of the inner mechanism of polymer electrolyte membrane fuel cell should be implement as much as possible, mathematical modeling is an important tool for the reach of the fuel cell especially with the combination of experiment. By regarding some of the assumptions and simplifications, using the finite element technique, a two-dimensional electrochemical mode is presented in this paper for the further comparison with experiment data. Based on the principals of the problem, the equation of electronic charge conservation equation, gas-phase continuity equation, and mass balance equation are used in calculating. In the end, the model results indicate the some of the phenomenon in the unit cell, and the relationships of potential and current density.
Effects of Flow Characteristics in Polymer Electrolyte Membrane Fuel Cell
An experimental and numerical study of polymer electrolyte membrane fuel cell (PEMFC) is presented and compared with the experimental data to investigate the effects of pressure gradient, flow rate, humidification and supplied oxidant type for the practical application. The membrane and electrolyte assembly (MEA) materials are implemented by double-tied catalyst layers. A single-phase two-dimensional steady-state model is is implemented for the numerical analysis. Testing condition is fixed at 60sccm and 70°C in anode and cathode, respectively. It is found that the performance of PEMFC depend highly on the conditions as gas pressure, temperature, thickness, supplied oxidant type (Oxygen/Air) as well as humidification. The results show that the humidification effect enhances the performance more than 20% and the pure oxygen gas as fuel improves current density more than 25% compared to ambient air suppliance as oxidant.
2010
Polymer Electrolyte Membrane (PEM) fuel cells are electrochemical power generators that converts the energy potential of a hydrogen-based fuel into electricity with water and heat as the major by-products. The sensitivity of the solid polymer membrane to temperature requires that thermal management of a PEM fuel cell stack operates efficiently to maintain the temperature at the optimal level. Air cooling is normally applied for industrial PEM fuel cells of up to 2 kW power output. A computational investigation on the effective micro cooling channel geometries was conducted in order to enhance the practical capability of air cooling for a 3 kW stack power output with a reduced conversion efficiency of 30%. Plate and stack assembly simulation cases of a single channel and 40 cooling channel configurations using Computational Fluid Dynamics (CFD) were conducted with constant heat generation. The cooling performance was evaluated based on the boundary heat transfer and shows 100% effect...
Water transport characteristics of polymer electrolyte membrane fuel cell
International Journal of Hydrogen Energy, 2004
This paper describes the performance of a polymer electrolyte membrane fuel cell (PEMFC) system without humidiÿcation of the reactants which consumes a lot of parasitic power, increases the weight of the PEMFC system and thus adds complexity. Such PEMFC systems are preferable for portable applications. The results indicate that dry gas operation depends on various factors like reactant ow ÿeld design, area of the electrode and equilibration time for the product water. The performance of the fuel cell can be improved by giving some equilibration time for the product water, produced by the electrochemical reactions, to get transported across the membrane to the anode side, thus increasing the conductivity of the membrane. The water transported through the membrane across the cell was investigated by measuring the amount of product water at the anode side which allows humidiÿcation for the anode gas and less condensed water in the uid ow channels of the cathode. ?
Analysis of PEM (Polymer Electrolyte Membrane) fuel cell cathode two-dimensional modeling
The performance of PEMFC (Polymer Electrolyte Membrane Fuel Cells) with different configuration of gas feeding channels is investigated. Multi-component mixture model is used in order to simulate the two phase flow and transport in cathode gas diffusion layer of PEM fuel cell. This model reduces the numerical simulation complexity by reducing the number of nonlinear governing equations. A wide detailed parametric study is done to investigate different operational parameter such as; pressure difference , operating temperature, different geometrical parameters such as; gas diffusion layer thickness, and various material parameters such as porosity and wettability. Computational simulations have been conducted and the simulation results were compared with the available results in literature and showed very little difference. Results have been presented with different polarization curves, power density and local current density curves and also the plots of saturation level at catalyst layer surface. Furthermore the changes in the place of the interface between single and two phase zones is presented for further understating of the effects of different parameters. This parametric study confirms qualitatively to the validity of the considered model for systematic simulation of the PEM fuel cells.
Defect and Diffusion Forum, 2008
In the present work, a three dimensional model examining the fluid flow along with the fundamental transport phenomena occurring in a typical polymer electrolyte fuel cell (PEMFC), i.e. heat transfer, mass transport and charge transfer, has been developed. The flow field was simulated according to the well known Navier-Stokes equations, while the heat transfer was described by the typical conduction/convection equation and the mass transport by the convection/diffusion one. Furthermore, reaction kinetics were studied by the Butler-Volmer equation for the heterogeneous reactions occurring at the porous electrodes. The developed model was numerically solved by using the commercially available CFD package CFD-RC © , which is based on the multi-step finite volume method. The fuel cell performance in terms of velocity, temperature, mass fractions of active compounds and electric field has been investigated as well.