Modeling Two-Phase Water Transport in Hydrophobic Diffusion Media for PEM Fuel Cells

2011 ◽  
Vol 158 (4) ◽  
pp. B384 ◽  
Author(s):  
David A. Caulk ◽  
Daniel R. Baker
Keyword(s):  
Fuel Cells ◽  
Water Transport ◽  
Pem Fuel Cells ◽  
Two Phase ◽  
Diffusion Media ◽  
Phase Water

Experimental characterization of the water transport properties of PEM fuel cells diffusion media

2012 ◽  
Vol 218 ◽  
pp. 221-232 ◽  
Author(s):  
Bladimir Ramos-Alvarado ◽  
Joshua D. Sole ◽  
Abel Hernandez-Guerrero ◽  
Michael W. Ellis
Keyword(s):  
Fuel Cells ◽  
Transport Properties ◽  
Water Transport ◽  
Pem Fuel Cells ◽  
Experimental Characterization ◽  
Diffusion Media ◽  
Water Transport Properties

Effect of Vibration on the Liquid Water Transport of PEM Fuel Cells

2009 ◽  
Author(s):  
Luis Breziner ◽  
Peter Strahs ◽  
Parsaoran Hutapea
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Water Transport ◽  
Liquid Water ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Sinusoidal Vibration ◽  
Fuel Cell Performance ◽  
Liquid Water Transport

The objective of this research is to analyze the effects of vibration on the performance of hydrogen PEM fuel cells. It has been reported that if the liquid water transport across the gas diffusion layer (GDL) changes, so does the overall cell performance. Since many fuel cells operate under a vibrating environment –as in the case of automotive applications, this may influence the liquid water concentration across the GDL at different current densities, affecting the overall fuel cell performance. The problem was developed in two main steps. First, the basis for an analytical model was established using current models for water transport in porous media. Then, a series of experiments were carried, monitoring the performance of the fuel cell for different parameters of oscillation. For sinusoidal vibration at 10, 20 and 50Hz (2 g of magnitude), a decrease in the fuel cell performance by 2.2%, 1.1% and 1.3% was recorded when compared to operation at no vibration respectively. For 5 g of magnitude, the fuel cell reported a drop of 5.8% at 50 Hz, whereas at 20 Hz the performance increased by 1.3%. Although more extensive experimentation is needed to identify a relationship between magnitude and frequency of vibration affecting the performance of the fuel cell as well as a throughout examination of the liquid water formation in the cathode, this study shows that sinusoidal vibration, overall, affects the performance of PEM fuel cells.

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.

Advanced Integrated Flow Field (IFF) Design for High Performance Fuel Cell and Electrolyzer

2014 ◽  
Author(s):  
Michael Pien ◽  
Steven Lis ◽  
Radha Jalan ◽  
Marvin Warshay ◽  
Suresh Pahwa
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Field ◽  
Gas Flow ◽  
Pem Fuel Cells ◽  
Water Flooding ◽  
Stoichiometric Ratio ◽  
Plant Design ◽  
Two Phase ◽  
Hydrophilic Matrix

Higher efficiency operation of PEM fuel cells needs an advanced passive way to remove product water. Water flooding in gas flow channels reduces efficiency and needs to be mitigated by a support of balance of plant design and components which results in parasitic power losses. ElectroChem’s Integrated Flow Field (IFF) design with the integration of hydrophobic and hydrophilic matrix has been proven to solve these challenges with no impact on the performance. The hydrophobic and hydrophilic matrix facilitates two phase (gas and liquid) flow to and away from the interface between the electrode membrane assembly and the flow field. A phase-separation feature of the IFF allowed the fuel cells to operate on a flow rate at its consumption rate. The IFF fuel cell has demonstrated operation at the ideal one stoichiometric ratio with 100% gas utilization and orientation independent. The IFF also served as gas humidifier through the creation of simultaneous distribution of gas and water within the cell. The self-humidification capability keeps the cell operating without the humidity of the input gas. The IFF design also enhanced the performance of water electrolysis which is a reverse process of fuel cell. The IFF supported the passive water feed to the cell and gas separation from the cell.

Sign in / Sign up

Export Citation Format

Share Document