Two-Phase Flow Analysis of Cathode Gas Diffusion Layer of Proton Exchange Membrane Fuel Cells
Date Issued
2005
Date
2005
Author(s)
Teng, Hong-She
DOI
en-US
Abstract
The proton exchange membrane (PEM) fuel cell is most anticipated among several kinds of substitute energy, particularly in the area of automotive technology. However, at high current density liquid water will hinder oxygen transport to reaction site especially in the cathode side and make them unrealistic for widely commercialization up to the present. How to improve the cell performance is very crucial. The study focuses on transport phenomena of cathode gas diffusion layer of PEM fuel cell by using two-phase flow model. Liquid water saturation and oxygen concentration profile in gas diffusion layer and polarization curve are investigated by numerical simulations. Results show that liquid water due to chemical reaction reduces effective porosity of gas diffusion layer and hinders oxygen transport to reaction site. When the gas diffusion media is more hydrophobic, the liquid water removal rate by the capillary force is faster. With the decreasing GDL porosity or the thicker GDL thickness, the mass transport limitation takes place at lower current density. Besides, since liquid water saturation in gas diffusion layer is higher, liquid water effect on the cell performance becomes more significant. With the longer channel length or the slower inlet velocity, the mass transport limitation also takes place at lower current density. And with the increasing current density, liquid water effect on the cell performance becomes more significant.
Subjects
質子交換膜燃料電池
氣體擴散層
兩相流
PEM fuel cell
gas diffusion layer
two-phase flow
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-R92543080-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):73fb23f2f68d187335cb2fcc62041554