Effects of rib structure and compression on liquid water transport in the gas diffusion layer of a polymer electrolyte membrane fuel cell

2022 ◽  
Author(s):  
Seung-Hun Lee ◽  
Hyung Min Kim
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Water Transport ◽  
Diffusion Layer ◽  
Liquid Water ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion ◽  
Electrolyte Membrane ◽  
Rib Structure ◽  
Liquid Water Transport

Effect of porosity gradient in cathode gas diffusion layer of polymer electrolyte membrane fuel cells on the liquid water transport using lattice Boltzmann method

2020 ◽  
pp. 095765092093431
Author(s):  
Mohammad Habiballahi ◽  
Hasan Hassanzadeh ◽  
Mohammad Rahnama ◽  
Seyed Ali Mirbozorgi ◽  
Ebrahim Jahanshahi Javaran
Keyword(s):  
Porous Media ◽  
Water Transport ◽  
Diffusion Layer ◽  
Liquid Water ◽  
Water Saturation ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Electrolyte Membrane ◽  
Liquid Water Transport

In this paper, a two-dimensional model has been developed to simulate the liquid water transport in a cathode gas diffusion layer with different porosity gradients in polymer electrolyte membrane fuel cells (PEMFCs). Due to the complexity of porous media, the simulation was carried out by lattice Boltzmann method. According to dimensionless numbers that characterize liquid water transport in porous media, simulation conditions were similar to the liquid water transfer into the gas diffusion layer of PEMFC. Different gas diffusion layers were created randomly by solid circular particles with an average diameter of [Formula: see text] and the numerical code was validated by conducting several tests. The results indicated that capillary force is the main factor in liquid water transport in the gas diffusion layer, while viscous and gravitational forces do not have a significant effect. In addition to improve the water management, the gas diffusion layer should have a positive porosity gradient, i.e. the porosity increases along the thickness. Also, under the same boundary conditions and at the average porosity (0.659), the saturation distribution curves in three porous media were compared including the gas diffusion layer with porosity gradient, the gas diffusion layer with the micro-porous layer, and the gas diffusion layer with uniform porosity. The average liquid water saturation in the gas diffusion layer with the 10% porosity gradient was 20.2% lower than in the gas diffusion layer with uniform porosity and 10.5% lower than the gas diffusion layer + micro-porous layer. Furthermore, upon elevation of the porosity gradient in the gas diffusion layer, the average liquid water saturation in the gas diffusion layer decreased. Specifically, as the porosity gradient rose from 10% to 14% and 18.5%, the average liquid water saturation values decreased to 29.8% and 38.8%, respectively compared with the gas diffusion layer with uniform porosity.

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