Effects of needle orientation and gas velocity on water transport and removal in a modified PEMFC gas flow channel having a hydrophilic needle

Abstract

Summary Water management is critical to the performance and operation of the proton exchange membrane fuel cell (PEMFC). Effective water removal from the gas diffusion layer (GDL) surface exposed to the gas flow channel in PEMFC mitigates the water flooding of and improves the reactants transport into the GDL, hence benefiting the PEMFC performance. In this study, a 3D numerical investigation of water removal from the GDL surface in a modified PEMFC gas flow channel having a hydrophilic needle is carried out. The effects of the needle orientation (inclination angle) and gas velocity on the water transport and removal are investigated. The results show that the water is removed from the GDL surface in the channel for a large range of the needle inclination angle and gas velocity. The water is removed more effectively, and the pressure drop for the flow in the channel is smaller for a smaller needle inclination angle. It is also found that the modified channel is more effective and viable for water removal in fuel cells operated at smaller gas velocity.

The energy performance improvement of a PEM fuel cell with various chaotic flowing channels

“…In Khan et al, developments of PEMFCs mathematical modeling were presented and summarized. The effects of temperature, pressure, and humidity on transport characteristics were discussed with their effects on the fuel cell performance . Yin et al established a 3‐D model with the installation of baffle plates.…”

Geometric pore surface area and fractal dimension of catalyzed electrodes in polymer electrolyte membrane fuel cells

“…It can be seen that the thickness of the sample is about 243 μm, while its bulk volume is 0.101 cm 3 based on Equation 9, respectively. The dry mass of the sample is 0.0478 g, and the bulk density is 0.4733 g cm −3 as defined in Equation 10. The accessible pore volume is determined based on the mass of the liquid in the totally octane-wetted sample, and with the known density of octane, the pore volume is determined as 0.066 cm 3 via Equation 8.…”

“…9 The pore structure of the entire electrode plays a vital role in facilitating the effective mass transport, water and heat management, and electrochemical reactions in PEM fuel cells. 3,10 The porous structures of the electrodes are practically represented by the structural parameters, such as porosity, pore size distribution (PSD), and bulk density. [11][12][13][14][15] The porosity is defined as the volumetric fraction of the void region in the bulk region.…”

The effect of ink dilution and evaporation on the microstructures of catalyst layers in polymer electrolyte membrane fuel cells

“…The electrochemical reactions occur in an ultra‐thin porous region (typically 5‐40 μm thick), which is known as the catalyst layers (CLs) in PEM fuel cells. The CL is conventionally composed of catalyst particles, ionomers, and pores for providing the functional microstructures that have sufficient number of active sites for reactions, pathways for proton and electron transport, and channels for reactant gas delivery and water management …”

“…The CL is conventionally composed of catalyst particles, ionomers, and pores for providing the functional microstructures that have sufficient number of active sites for reactions, pathways for proton and electron transport, and channels for reactant gas delivery and water management. [3][4][5][6][7][8] Recent studies indicate that the inhomogeneity of the microstructures of the CLs at different length-scales is not only essential for the required functions but also a root reason for degradation and malfunction in PEM fuel cells. 3,[9][10][11] Figure 1 illustrates the relation between CL microstructures and degradation mechanisms in PEM fuel cells.…”