Physical Parameters Affecting on the Electrode Performance for Proton Exchange Membrane Fuel Cells (PEMFCs)

2015 ◽  
Vol 1105 ◽  
pp. 320-324
Author(s):  
Chebbi Rachid ◽  
Wan Ramli Wan Daud ◽  
Beicha Abdellah ◽  
Mohd Ambar Yarmo

Physical parameters effects are considered as sticking point to increase and decrease the electrode performance for PEMFCs, which is related to the electrode structural degradation under diverse operating conditions, such as various air and hydrogen pressures, humidifier temperatures, and air and hydrogen flow rates. The operating for electrode prepared with 20 wt% Pt loaded 0.3 mgPt/cm2 in single cell (25 cm2) showed that diverse parameters as pressures, humidifier temperatures, flow rate of air /hydrogen have an effects on the electrode performance. Results show better power density for high pressure, high air flow rate, and for low humidifier temperature, low H2 flow rate. The increase in pressure ratio results increases in the current density and power density from 91.96 to 99.96 mA/cm2 and from 32.56{mW/cm2} to 35.48 {mW/cm2} for an air/H2 ratio of 1/0.5 bar and 3/2 bar, respectively. The hydrogen and air flow with the stoichiometry coefficient ratio 2/1 is the best value to achieve better performance by a flow rate of 0.3 L/min for H2 and 0.6 L/min for air, which correspond to a current density and power density of 103.96{mA/cm2} and 31.56{mW/cm2}.

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1546
Author(s):  
Árpád Imre-Lucaci ◽  
Melinda Fogarasi ◽  
Florica Imre-Lucaci ◽  
Szabolcs Fogarasi

This paper presents a novel approach for the recovery of lead from waste cathode-ray tube (CRT) glass by applying a combined chemical-electrochemical process which allows the simultaneous recovery of Pb from waste CRT glass and electrochemical regeneration of the leaching agent. The optimal operating conditions were identified based on the influence of leaching agent concentration, recirculation flow rate and current density on the main technical performance indicators. The experimental results demonstrate that the process is the most efficient at 0.6 M acetic acid concentration, flow rate of 45 mL/min and current density of 4 mA/cm2. The mass balance data corresponding to the recycling of 10 kg/h waste CRT glass in the identified optimal operating conditions was used for the environmental assessment of the process. The General Effect Indices (GEIs), obtained through the Biwer Heinzle method for the input and output streams of the process, indicate that the developed recovery process not only achieve a complete recovery of lead but it is eco-friendly as well.


2010 ◽  
Vol 177 ◽  
pp. 407-410
Author(s):  
Xi Bao Li ◽  
Jian Wang ◽  
Xiao Hua Yu ◽  
Hong Xing Gu ◽  
Gang Qin Shao

NiO-YSZ (NiO-yttria stabilized zirconia, 3:2, wt.%) and samaria doped ceria (SDC) tapes were prepared by aqueous tape casting. NiO-YSZ anode-supported SDC film electrolyte half-cell was fabricated by laminating and co-sintering at 1400°C for 2 h. The single cell was prepared after LSCF-SDC (lanthanum strontium cobalt ferrite-SDC, 1:1, wt.%) cathode was coated on the electrolyte surface and sintered at 1300 °C for 2 h. The discharge performance of the single cell was tested from 500 °C to 800 °C at different H2 flow rate. Results showed that the relationship between current (I) of and H2 flow rate (ν) was I = 8 × 106 ν. Before reaching the threshold value of H2 flow rate, the current density of single cell increased with the increasing of H2 flow rate. However, the current density did not change with increasing of H2 flow rate over the threshold value. The open circuit voltage (OCV) of single cell at 500°C, 600°C, 700°C, 800°C was 0.978, 0.921, 0.861, 0.803 V, respectively. The maximum power density reached 93.03 mW/cm2 at 800°C. The resistance of interface layer between Ni-YSZ anode and SDC electrolyte was the key impact on the power density.


Author(s):  
Utku Gulan ◽  
Hasmet Turkoglu ◽  
Irfan Ar

In this study, the fluid flow and cell performance in cathode side of a proton exchange membrane (PEM) fuel cell were numerically analyzed. The problem domain consists of cathode gas channel, cathode gas diffusion layer, and cathode catalyst layer. The equations governing the motion of air, concentration of oxygen, and electrochemical reactions were numerically solved. A computer program was developed based on control volume method and SIMPLE algorithm. The mathematical model and program developed were tested by comparing the results of numerical simulations with the results from literature. Simulations were performed for different values of inlet Reynolds number and inlet oxygen mole fraction at different operation temperatures. Using the results of these simulations, the effects of these parameters on the flow, oxygen concentration distribution, current density and power density were analyzed. The simulations showed that the oxygen concentration in the catalyst layer increases with increasing Reynolds number and hence the current density and power density of the PEM fuel cell also increases. Analysis of the data obtained from simulations also shows that current density and power density of the PEM fuel cell increases with increasing operation temperature. It is also observed that increasing the inlet oxygen mole fraction increases the current density and power density.


2016 ◽  
Vol 20 (5) ◽  
pp. 1421-1433 ◽  
Author(s):  
Ismet Tikiz ◽  
Imdat Taymaz

Cell temperature and selection of the reactant gases are crucial parameters for the design and optimization of fuel cell performance. In this study, effect of operating conditions on the performance of Solid Oxide Fuel (SOFC) has been investigated. Application of Response Surface Methodology (RSM) was applied to optimize operations conditions in SOFC. For this purpose, an experimental set up for testing of SOFC has been established to investigate the effect of Hydrogen, Oxygen, Nitrogen flow rates and cell temperature parameters on cell performance. Hydrogen flow rate, oxygen flow rate, nitrogen flow rate and cell temperature were the main parameters considered and they were varied between 0.25 and 1 L/min, 0.5 and 1 L/min, 0 and 1 L/min and 700-800 oC in the analyses respectively. The maximum power density was found as 0.572 W/cm2 in the experiments.


2013 ◽  
Vol 34 (4) ◽  
pp. 187-197 ◽  
Author(s):  
Andrzej Kacprzak ◽  
Rafał Kobyłecki ◽  
Zbigniew Bis

Abstract The influences of various operating conditions including cathode inlet air flow rate, electrolyte temperature and fuel particles size on the performance of the direct carbon fuel cell DCFC were presented and discussed in this paper. The experimental results indicated that the cell performance was enhanced with increases of the cathode inlet gas flow rate and cell temperature. Binary alkali hydroxide mixture (NaOH-LiOH, 90-10 mol%) was used as electrolyte and the biochar of apple tree origin carbonized at 873 K was used as fuel. Low melting temperature of the electrolyte and its good ionic conductivity enabled to operate the DCFC at medium temperatures of 723-773 K. The highest current density (601 A m−2) was obtained for temperature 773 K and air flow rate 8.3×106 m3s−1. Itwas shown that too low or too high air flow rates negatively affect the cell performance. The results also indicated that the operation of the DCFC could be improved by proper selection of the fuel particle size.


Author(s):  
F. L. Muhamedin ◽  
M. A. M. Piah ◽  
N. A. Othman ◽  
Nasir Ahmed Algeelani

<p>Electrical failure due to surface discharge on the insulation material will cause material degradation and eventually lead to system failure. The flow of leakage current (LC) on the insulator surface under wet contamination is used to determine the material degradation level. According to IEC 60587 standard, LC exceeding 60 mA for more than two seconds is considered as failure. In this study, the  electric field and current density distributions on the linear low-density polyethylene (LLDPE) and natural rubber blend material have been analyzed using finite element method (FEM) analysis. The physical parameters used in FEM simulation were applied with voltage and contaminant flow rate, in accordance to contaminant conductivity. Tracking test condition according to IEC 60587 standard has been applied as proposed by the reference work in simulation using QuickField FEM software. The results show that the electric field and current density would become critical in higher applied voltage and contaminant flow rate. The highest average and highest maximum current density and electric field are found in both applied voltage of 6 kV and contaminant flow rate of 0.90 mlmin<sup>-1</sup>.</p>


2005 ◽  
Vol 2 (2) ◽  
pp. 121-135 ◽  
Author(s):  
A. Mawardi ◽  
F. Yang ◽  
R. Pitchumani

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.


Author(s):  
A. B. Mahmud Hasan ◽  
S. M. Guo ◽  
S. V. Ekkad

The performance of a Proton Exchange Membrane Fuel Cell (PEMFC) using different feeding configurations has been studied. Three bipolar plates, namely serpentine, straight channel and interdigitated designs, were arranged in different combinations for the PEMFC anode and cathode sides. Nine combinations in total were tested under different flow rates, working temperatures and loadings. The cell voltage versus current density and the cell power density versus current density curves were obtained. After operating the PEMFC under high current densities, the cell was split and the water flooding in the feeding channels was visually inspected. Experimental results showed that for different feeding configurations, interdigitated bipolar plate in anode side and serpentine bipolar plate in cathode side had the best performance in terms of cell voltage-current density curve, power density output rate, percentage of flooded area in the feeding channels, the pattern of flooding and the fuel utilization rate.


Author(s):  
H. E. Hill ◽  
W. F. Ng ◽  
P. P. Vlachos ◽  
S. A. Guillot ◽  
D. Car

Circulation control inlet guide vanes (IGVs) may provide significant benefits over current IGVs that employ mechanical means for flow turning. This paper presents the results of a two-dimensional computational study on a circulation control IGV that takes advantage of the Coanda effect for flow vectoring. The IGV in this study is an uncambered airfoil that alters circulation around itself by means of a Coanda jet that exhausts along the IGV’s trailing edge surface. The IGV is designed for an axial inlet flow at a Mach number of 0.54 and an exit flow angle of 11 degrees. These conditions were selected to match the operating conditions of the 90% span section of the IGV of the TESCOM compressor rig at the Compressor Aero Research Laboratory (CARL) located at Wright-Patterson AFB, the hardware that is being used as the baseline in this study. The goal of the optimization was to determine the optimal jet height, trailing edge radius, and supply pressure that would meet the design criteria while minimizing the mass flow rate and pressure losses. The optimal geometry that was able to meet the design requirements had a jet height of h/Cn = 0.0057 and a trailing edge Radius R/Cn = 0.16. This geometry needed a jet to inflow total pressure ratio of 1.8 to meet the exit turning angle requirement. At this supply pressure ratio the mass flow rate required by the flow control system was 0.71 percent of the total mass flow rate through the engine. The optimal circulation control IGV had slightly lower pressure losses when compared with a reference cambered IGV.


Sign in / Sign up

Export Citation Format

Share Document