Numerical studies on an air-breathing proton exchange membrane (PEM) fuel cell stack

2007 ◽  
Vol 173 (1) ◽  
pp. 264-276 ◽  
Author(s):  
Y. Zhang ◽  
A. Mawardi ◽  
R. Pitchumani
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Air Breathing ◽  
Fuel Cell Stack ◽  
Numerical Studies ◽  
Exchange Membrane

ac Impedance Study of a Proton Exchange Membrane Fuel Cell Stack Under Various Loading Conditions

2010 ◽  
Vol 7 (3) ◽  
Author(s):  
N. V. Dale ◽  
M. D. Mann ◽  
H. Salehfar ◽  
A. M. Dhirde ◽  
T. Han
Keyword(s):  
Fuel Cell ◽  
Single Cell ◽  
Proton Exchange Membrane ◽  
Low Frequency ◽  
Impedance Analysis ◽  
Pem Fuel Cell ◽  
Ac Impedance ◽  
Proton Exchange ◽  
Fuel Cell Stack ◽  
Exchange Membrane

This paper presents the ac impedance study and analysis of a proton exchange membrane (PEM) fuel cell operated under various loading conditions. Ballard’s 1.2 kW Nexa™ fuel cell used for this study is integrated with a control system. The PEM fuel cell stack was operated using room air and pure hydrogen (99.995%) as input. Impedance data were collected for the fuel cell to study the behavior of the stack and groups of cells under various loads. Single cell impedance analysis was also performed for individual cells placed at different locations in the stack. The ac impedance analysis, also known as electrochemical impedance analysis, showed low frequency inductive effects and mass transport losses due to liquid water accumulation at high current densities. Results show that the stack run time to achieve steady state for impedance measurements is important. Using impedance plots, the average Ohmic resistance for the whole stack was estimated to be 41 mΩ, the same value obtained when summing the resistance value of all individual cells. Impedance analysis for groups of cells at different locations in the stack shows changes in both polarization resistance and capacitive component only in the low frequency region. At high frequencies, single cell inductive and capacitive behavior varied as a function of location in the stack. The effects of artifacts on the high frequency loop and on the high and low frequency intercept loops are also discussed.

Mass Transports in an Air-Breathing Cathode of a Proton Exchange Membrane Fuel Cell

2009 ◽  
Vol 6 (4) ◽  
Author(s):  
J. J. Hwang ◽  
W. R. Chang ◽  
C. H. Chao ◽  
F. B. Weng ◽  
A. Su
Keyword(s):  
Fuel Cell ◽  
Mass Transport ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Air Breathing ◽  
Coupled Equations ◽  
Porous Cathode ◽  
Porous Cathodes ◽  
Exchange Membrane

Mass transport in an air-breathing cathode of a proton exchange membrane (PEM) fuel cell was investigated numerically. The porous cathode in contact with a perforated current collector breathes fresh air through an array of orifices. The diffusions of reactant species in the porous cathodes are described using the Stefan–Maxwell equation. The electrochemical reaction on the surfaces of the porous cathode is modeled using the Butler–Volmer equation. Gas flow in the air-breathing porous cathodes is described using isotropic linear resistance model with constant porosity and permeability. The electron/ion transports in the catalyst/electrolyte are handled using charge conservation based on Ohm’s law. A finite-element scheme is adopted to solve these coupled equations. The effects of electrode porosity (0.4<ε<0.6) on the fluid flow, mass transport, and electrochemistry are examined. Detailed electrochemical/mass characteristics, such as flow velocities, species mass fraction, species flux, and current density distributions are presented. These details provide a solid basis for optimizing the geometry of a PEM fuel cell stack that is run in passive mode.

Experimental Evaluation of the Dynamic Behavior of an Air-Breathing Fuel Cell Stack

2001 ◽  
Vol 123 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Svein O. Morner ◽  
Sanford A. Klein
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Significant Variable ◽  
Transient Effects ◽  
Air Breathing ◽  
Fuel Cell Stack ◽  
Fuel Cell Performance ◽  
Effects Of Temperature ◽  
Exchange Membrane

The performance of an air breathing proton exchange membrane (PEM) fuel cell stack has been experimentally measured to investigate the steady-state and transient effects of temperature, humidity and air flowrate. The results show that hydrogen leaks to the cathode through the membrane causing internal heating of the fuel cell. The leakage rate is found to be linearly dependent on the pressure difference between the hydrogen side and air side which is at atmospheric pressure. Temperature was found to not have a significant effect on the PEM performance, except through its indirect effect on humidity. The humidity of the membrane is found to be the most significant variable in determining the fuel cell performance. The airflow also influences the performance of the fuel cell directly by supplying oxygen and indirectly by influencing the humidity of the membrane. Experiments show that an optimum air flowrate exists that is much larger than required for stoichiometric oxidation of the fuel.

Development of a Proof-of-Concept Proton Exchange Membrane Fuel Cell Powered Scooter

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Georgiy Diloyan ◽  
Luis Breziner ◽  
Parsaoran Hutapea
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Rear Wheel ◽  
Proton Exchange ◽  
Fuel Cell Stack ◽  
Brushless Motor ◽  
Air Supply ◽  
In Series ◽  
Exchange Membrane

The objective of this project is to develop a proton exchange membrane (PEM) fuel cell powered scooter with a designed digital controller to regulate the air supply to PEM fuel cell stack. A 500-Watt (W) electric power train was chosen as a platform for the scooter. Two 300 W PEM fuel cell systems, each containing 63 cells, were used to charge 48-Volt batteries that powered an electric motor. The energy carrier (hydrogen) was stored in two metal hydride tanks, each one containing 85 gs of hydrogen pressurized to 250 psig. The output hydrogen pressure from each tank was maintained at 5.8 psi by a two-stage pressure regulator, and then delivered to each fuel cell stack. To regulate the voltage of each PEM fuel cell under different load conditions, two step down DC/DC converters were used. These converters were connected in series to power the motor controller and charge the batteries. The batteries then supplied power to the 500 W brushless motor mounted to the hub of the rear wheel to save space. After all modifications were completed, most of the parts of the scooter stayed the same except for the panel under the seat—where larger space is needed for accommodating the hydrogen tanks. The weight of the scooter did not change significantly, because the weight of the hydrogen tanks (6.5 kg each) and fuel cell stacks (1.7 kg each) was partially compensated by replacing the batteries from the old ones that weighed 17.5 kg to new ones that weighed 9 kg.

scholarly journals An Artificial Intelligence Solution for Predicting Short-Term Degradation Behaviors of Proton Exchange Membrane Fuel Cell

2021 ◽  
Vol 11 (14) ◽  
pp. 6348
Author(s):  
Zijun Yang ◽  
Bowen Wang ◽  
Xia Sheng ◽  
Yupeng Wang ◽  
Qiang Ren ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Activation Function ◽  
Proton Exchange ◽  
Cell Performance ◽  
Short Term ◽  
Degradation Behaviors ◽  
Hidden Layer ◽  
Exchange Membrane

The dead-ended anode (DEA) and anode recirculation operations are commonly used to improve the hydrogen utilization of automotive proton exchange membrane (PEM) fuel cells. The cell performance will decline over time due to the nitrogen crossover and liquid water accumulation in the anode. Highly efficient prediction of the short-term degradation behaviors of the PEM fuel cell has great significance. In this paper, we propose a data-driven degradation prediction method based on multivariate polynomial regression (MPR) and artificial neural network (ANN). This method first predicts the initial value of cell performance, and then the cell performance variations over time are predicted to describe the degradation behaviors of the PEM fuel cell. Two cases of degradation data, the PEM fuel cell in the DEA and anode recirculation modes, are employed to train the model and demonstrate the validation of the proposed method. The results show that the mean relative errors predicted by the proposed method are much smaller than those by only using the ANN or MPR. The predictive performance of the two-hidden-layer ANN is significantly better than that of the one-hidden-layer ANN. The performance curves predicted by using the sigmoid activation function are smoother and more realistic than that by using rectified linear unit (ReLU) activation function.

Observation of Pressure Drop Behavior in an Operating Fuel Cell Stack

2005 ◽  
Author(s):  
Frano Barbir ◽  
Haluk Gorgun ◽  
Xinting Wang
Keyword(s):  
Fuel Cell ◽  
Pressure Drop ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Cathode Side ◽  
Fuel Cell Stack ◽  
Flow Through ◽  
Drying Conditions ◽  
Exchange Membrane ◽  
The Relationship

Pressure drop on the cathode side of a PEM (Proton Exchange Membrane) fuel cell stack has been studied and used as a diagnostic tool. Since the Reynolds number at the beginning of the flow field channel was <250, the flow through the channel is laminar, and the relationship between the pressure drop and the flow rate is linear. Some departure from linearity was observed when water was either introduced in the stack or produced inside the stack in the electrochemical reaction. By monitoring the pressure drop in conjunction with the cell resistance in an operational fuel cell stack, it was possible to diagnose either flooding or drying conditions inside the stack.

Sign in / Sign up

Export Citation Format

Share Document