2024-03-29T21:33:30Z
https://hfe.irost.ir/?_action=export&rf=summon&issue=155
Hydrogen, Fuel Cell & Energy Storage
HFE
2980-8537
2980-8537
2020
7
1
Developed endplate geometry for uniform contact pressure distribution over PEMFC active area
Mohammad
Barzegari
Mojtaba
Ghadimi
Mostafa
Habibnia
Mohammad
Momenifar
Kamal
Mohammadi
Contact resistance among the components of a polymer exchange membrane fuel cell (PEMFC) has a crucial effect on cell performance. The geometry of the endplate plays an essential role in the contact pressure distribution over the membrane electrode assembly (MEA) and the amount of contact resistance between plates. In this work, the effects of endplate geometry on the contact pressure distribution over the MEA have been explored through computational simulations using ABAQUS software. A new geometry for the endplate has been proposed and was then compared to flat endplates. Geometrical parameters of an endplate having a curvature (bomb-shaped endplate) were considered, and the effects of these parameters on the contact pressure distribution over the MEA were investigated. Through the simulations, a 3D model of the fuel cell was developed. The simulation results showed good performances for the designed endplate and uniform contact pressure distribution on the fuel cell active area. Finally, a single fuel cell was manufactured and assembled using the simulation parameters, and experimental tests were conducted using pressure measurement film to evaluate the design.
Geometry of endplate
Contact pressure distribution
Membrane electrode assembly
Finite element simulation
Pressure measurement film
2020
06
01
1
12
https://hfe.irost.ir/article_902_64dbb4eb4cef22c1dfc64a1e5ad43773.pdf
Hydrogen, Fuel Cell & Energy Storage
HFE
2980-8537
2980-8537
2020
7
1
Exergy and Energy Analysis of Effective Utilization of Carbon Dioxide in the Gas-to-Methanol Process
Nima
Norouzi
Saeed
Talebi
Two process models are used to convert carbon dioxide into methanol. These processes have been extended and improved using Aspen Plus simulator software. Both processes are found in the CO2 correction system. In this machine, the desired synthesis gas is produced in a flexible configuration. At the same time, the conversion of CO2 to hydrogen via a copper-based catalyst has been accomplished in the methanol blending and bonding machine to produce the target product, methanol. The simulation results show that, in both proposed CO2-gas-to-methanol process, the energy efficiency can be significantly increased, and the CO2 emission significantly reduced as compared to the conventional Gas-to-methanol process. Energy efficiency is also affected by the recycling factor. The higher the recycling factor, the better the CO2 conversion and reaction will be as well as increased energy efficiency and decreased CO2 emission. However, the refractive index seems to have little effect on energy efficiency, and the useful recovery that goes back to the breeder is meager. Implementation of the carbon dioxide utilization process for gas-to-methanol units has significant impacts on these systems in the term of energy and exergy, the performance ratios increased 6.5 and 4.2%, respectively, compared to the base cases. Regarding exergoeconomics, the exergy cost rate decreased 71 $/s. An exergoenvironmental analysis showed the impacts are significant. The environmental impact difference increased by 3%, which, because of its definite form, means a carbon dioxide utilization plant makes a more significant positive difference in the environment.
Greenhouse gas
Carbon dioxide utilization
Methanol
Exergy analysis
2020
06
25
13
31
https://hfe.irost.ir/article_903_eb42e08ef33b21c5bc15b96d9f6a0989.pdf
Hydrogen, Fuel Cell & Energy Storage
HFE
2980-8537
2980-8537
2020
7
1
Experimental Study of Oxidant Effect on Lifetime of PEM Fuel Cell
Mojtaba
Hassani
Majid
Rahgoshay
Mazaher
Rahimi-Esbo
Kamran
Dadashi Firouzjaei
In recent decades, fuel cells have been widely used in energy generation. In a PEMFC, considering the specific application, two types of oxidants are used. Durability tests, which are highly costly products, are of crucial importance in evaluating the lifetime of fuel cells. The purpose of the present paper is to investigate the performance of a fuel cell by changing the type of oxidant from air to pure oxygen. Because of the presence of impurities in the air oxidant, a cell with air oxidant is more sensitive to operating conditions than one with pure oxygen. In this experiment, a single fuel cell was assembled and used for testing. The lifetime test was carried out in constant current, and the voltage decay rate was reported. Effects of various parameters, like air stoichiometry, Dew point Temperature, and Pressure, have been investigated. Increasing the stoichiometry of the oxidant to 3 greatly increased the voltage of the fuel cell, but no significant increase in the fuel cell voltage was observed in stoichiometries above this value. A comparison of inlet gas temperatures demonstrated that the fuel cell had the best performance at 75 °C, but due to the fluctuation of the output voltage at this temperature, the temperature was decreased to 65 °C. Finally, upon performing durability test with pure oxygen for 9 hours and comparing the results with those of air oxidant, the possibility of using a fuel cell with two different oxidants has been confirmed.
Long-term test
Oxidant Type
PEM fuel cell
Stoichiometry
Voltage Decay
2020
06
25
33
43
https://hfe.irost.ir/article_913_a08628496c7c279af4029471e94c364e.pdf
Hydrogen, Fuel Cell & Energy Storage
HFE
2980-8537
2980-8537
2020
7
1
Lattice Boltzmann simulation of water transfer in gas diffusion layers with porosity gradient of polymer electrolyte membrane fuel cells with parallel processing on GPU
mohammad
habiballahi
Hassan
Hassanzadeh
mohammad
rahnama
seyed ali
mirbozorgi
Ebrahim
Jahanshahi Javaran
This study used the lattice Boltzmann method (LBM) to evaluate water distribution in the gas diffusion layer (GDL) of cathode PEM fuel cells (PEMFCs) with porosity gradient. Due to the LBM’s capability of parallel processing with a GPU and the high volume of computing necessary, especially for small grids, the GPU parallel processing was done on a graphics card with the help of CUDA to speed up computing. The two-phase flow boundary conditions in the GDL are similar to the water transfer in the GDL of the PEMFCs. The results show that capillary force is the main cause of water transfer in the GDL, and gravity has little effect on the water transfer. Also, the use of GPU parallel processing on the graphics card increases the computation speed up to 17 times, which has a significant effect on running time. To investigate the gradient of porosity of GDLs with different porosity gradients, but the same average porosity coefficient and the same particle diameter have been evaluated. The simulation results show that the GDL with a 10% porosity gradient compared to the GDL with uniform porosity results in a 20.2% reduction in the amount of liquid water in the porous layer. Hence, increasing the porosity gradient of the GDL, further decreases the amount of liquid water in the porous layer. So, for the GDL with a porosity gradient of 14% this decrease is 29.8% and for the GDL with porosity gradient 18.5% this decrease is 38.8% compared to the GDL with uniform porosity.
PEM fuel cell
Lattice Boltzmann Method
Gas Diffusion Layer
two-phase flow
GPU parallel processing
porosity gradient
2020
06
01
45
60
https://hfe.irost.ir/article_905_ef1c183016d8bf965921b72d6d295395.pdf
Hydrogen, Fuel Cell & Energy Storage
HFE
2980-8537
2980-8537
2020
7
1
Lattice Boltzmann Modeling of Methane Steam Reforming Reactions in Solid Oxide Fuel Cells
Mehdi
Rahimi Takami
Davood
Domairry Ganji
Mojtaba
Aghajani Delavar
Shahriar
Bozorgmehri
The present study evaluated the rate of methane steam reforming (MSR) in a solid oxide fuel cell (SOFC). In this regard, a numerical model is applied to investage the effects of different parameters on the reactants concentration and temperature distributions in the SOFCs. The developed model is based on the Lattice Boltzmann method (D2Q9) and validated with experimental results. Parametric effects, including current density, anode porosity, steam to carbon ratio (S/C), and Reynolds number of the inlet flow in the anode channel, are surveyed as a new parameter. Also, the results of reactant concentrations are illustrated in two-dimensions. These results showed that the porosity and Reynolds number of flow have the lowest and highest impact on the reaction rate of MSR, respectively. The lowest MSR rate at the center of the SOFC happened when the Reynolds number of the input flow equals 5, and the highest MSR rate occured when the Reynolds number is 15 or the steam to carbon ratio equaled to 1.
Solid oxide fuel cell
Methane Steam Reforming
Lattice Boltzmann Method
Reaction rate
Concentration distribution
2020
09
30
61
79
https://hfe.irost.ir/article_940_483b19a241f5a00ee123b83656484e24.pdf
Hydrogen, Fuel Cell & Energy Storage
HFE
2980-8537
2980-8537
2020
7
1
Design and Analysis of an Innovative Dead-end Cascade-type PEMFC Stack at Different Orientations
Mazaher
Rahimi-Esbo
Mohammad
Barzegari
Majid
khorshidian
Majid
Rahgoshay
In this paper, the design and experimental study of a 4-cells cascade-type polymer electrolyte membrane (PEM) fuel cell stack with integrated humidifiers and water separators are presented. The PEM fuel cell stack is subdivided into two stages to minimize the quantity of exhaust gases during operation. A dead-end condition is applied for both cathode and anode sides of the PEM fuel cell stack. In a dead-end mode, the end-stage is designed to entirely use the reactant gases in the operation. Periodical purging is utilized to remove the accumulated water or impurities from the cascade-type PEM fuel cell stack. Comparison of cascade-type PEM fuel cell stack operation in a dead-end mode with a flow-through mode is performed. Results revealed that integrating humidifiers and water separators with the stack improved the volume power density of the PEM fuel cell stack. Moreover, since more liquid water was produced on the cathode side, the fluctuation of purge cell voltage of the cathode side is higher than that of the anode side. In addition, a technique is applied to control the pressure fluctuation of both sides of the PEM fuel cell.
Experimental study
Cascade-type PEM fuel cell
Dead-end condition
Stack design
2020
12
16
81
96
https://hfe.irost.ir/article_977_898ec6c6f47cb3e8d516367fb3f152e2.pdf