Channel Geometry Effect for Proton Exchange Membrane Fuel Cell With Serpentine Flow Field Using a Three-Dimensional Two-Phase Model

2010 ◽  
Vol 7 (5) ◽  
Author(s):  
Xiao-Dong Wang ◽  
Xin-Xin Zhang ◽  
Tao Liu ◽  
Yuan-Yuan Duan ◽  
Wei-Mon Yan ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Water Transport ◽  
Liquid Water ◽  
Proton Exchange Membrane ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Two Phase ◽  
Serpentine Flow Field ◽  
Liquid Water Transport

This study presents a complete three-dimensional, two-phase transport model for proton exchange membrane fuel cells based on the two-fluid method, which couples the mass, momentum, species, and electrical potential equations. The different liquid water transport mechanisms in the flow channels, gas diffusion layers, catalyst layers, and membrane are modeled using two different liquid water transport equations. In the flow channels, gas diffusion layers, and catalyst layers, the generalized Richards equation is used to describe the liquid water transport including the effect of the pressure gradient, capillary diffusion, evaporation and condensation, and electro-osmotic, while in the membrane, the liquid water transport equation only takes into account the effect of back diffusion and electro-osmotic. Springer’s model is utilized on the catalyst layer-membrane interface to maintain continuum of the liquid water distribution. The model is used to investigate the effect of flow channel aspect ratio on the performance of fuel cells with single and triple serpentine flow fields. The predictions show that for both flow fields, the cell performance improves with decreasing aspect ratio. The aspect ratio has less effect on the cell performance for the triple serpentine flow field than for the single serpentine flow field due to the weaker under-rib convection.

The Effect of Inhomogeneous Compression on Water Transport in the Cathode of a Proton Exchange Membrane Fuel Cell

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Anders C. Olesen ◽  
Torsten Berning ◽  
Søren K. Kær
Keyword(s):  
Porous Media ◽  
Fuel Cell ◽  
Water Transport ◽  
Diffusion Layer ◽  
Liquid Water ◽  
Proton Exchange Membrane ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Exchange Membrane ◽  
Liquid Water Transport

A three-dimensional, multicomponent, two-fluid model developed in the commercial CFD package CFX 13 (ANSYS Inc.) is used to investigate the effect of porous media compression on water transport in a proton exchange membrane fuel cell (PEMFC). The PEMFC model only consist of the cathode channel, gas diffusion layer, microporous layer, and catalyst layer, excluding the membrane and anode. In the porous media liquid water transport is described by the capillary pressure gradient, momentum loss via the Darcy-Forchheimer equation, and mass transfer between phases by a nonequilibrium phase change model. Furthermore, the presence of irreducible liquid water is taken into account. In order to account for compression, porous media morphology variations are specified based on the gas diffusion layer (GDL) through-plane strain and intrusion which are stated as a function of compression. These morphology variations affect gas and liquid water transport, and hence liquid water distribution and the risk of blocking active sites. Hence, water transport is studied under GDL compression in order to investigate the qualitative effects. Two simulation cases are compared; one with and one without compression.

scholarly journals Scaling up Studies on PEMFC Using a Modified Serpentine Flow Field Incorporating Porous Sponge Inserts to Observe Water Molecules

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 286
Author(s):  
Muthukumar Marappan ◽  
Rengarajan Narayanan ◽  
Karthikeyan Manoharan ◽  
Magesh Kannan Vijayakrishnan ◽  
Karthikeyan Palaniswamy ◽  
...  
Keyword(s):  
Flow Field ◽  
Proton Exchange Membrane ◽  
Electrochemical Impedance ◽  
Scaling Up ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Experimental Investigations ◽  
Serpentine Flow Field ◽  
Exchange Membrane ◽  
Power Densities

Flooding of the cathode flow channel is a major hindrance in achieving maximum performance from Proton Exchange Membrane Fuel Cells (PEMFC) during the scaling up process. Water accumulated between the interface region of Gas Diffusion Layer (GDL) and rib of the cathode flow field can be removed by the use of Porous Sponge Inserts (PSI) on the ribs. In the present work, the experimental investigations are carried out on PEMFC for the various reaction areas, namely 25, 50 and 100 cm2. Stoichiometry value of 2 is maintained for all experiments to avoid variations in power density obtained due to differences in fuel utilization. The experiments include two flow fields, namely Serpentine Flow Field (SFF) and Modified Serpentine with Staggered provisions of 4 mm PSI (4 mm × 2 mm × 2 mm) Flow Field (MSSFF). The peak power densities obtained on MSSFF are 0.420 W/cm2, 0.298 W/cm2 and 0.232 W/cm2 compared to SFF which yields 0.242 W/cm2, 0.213 W/cm2 and 0.171 W/cm2 for reaction areas of 25, 50 and 100 cm2 respectively. Further, the reliability of experimental results is verified for SFF and MSSFF on 25 cm2 PEMFC by using Electrochemical Impedance Spectroscopy (EIS). The use of 4 mm PSI is found to improve the performance of PEMFC through the better water management.

A Low Order Control-Oriented Model of Liquid Water Transport in PEM Fuel Cell

2008 ◽  
Author(s):  
Angelo Esposito ◽  
Cesare Pianese ◽  
Yann G. Guezennec
Keyword(s):  
Fuel Cell ◽  
Water Transport ◽  
Diffusion Layer ◽  
Liquid Water ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Computational Time ◽  
Liquid Water Transport

In this work, an accurate and computationally fast model for liquid water transport within a proton exchange membrane fuel cell (PEMFC) electrode is developed by lumping the space-dependence of the relevant variables. Capillarity is considered as the main transport mechanism within the gas diffusion layer (GDL). The novelty of the model lies in the simulation of the water transport at the interface between gas diffusion layer and gas flow channel (GFC). This is achieved with a phenomenological description of the process that allows its simulation with relative simplicity. Moreover, a detailed two-dimensional visualization of such interface is achieved via geometric simulation of water droplets formation, growth, coalescence and detachment on the surface of the GDL. The accomplishment of reduced computational time and good accuracy makes the model suitable for control strategy implementation to ensure PEM fuel cells operation within optimal electrode water content. Furthermore, the model is useful for optimization analysis oriented to both PEMFC design and balance of plant.

Two-Phase Flow Considerations in PEMFC Design and Operation

2008 ◽  
Author(s):  
Jon P. Owejan ◽  
Jeffrey J. Gagliardo ◽  
Jacqueline M. Sergi ◽  
Thomas A. Trabold
Keyword(s):  
Liquid Water ◽  
Proton Exchange Membrane ◽  
Two Phase Flow ◽  
Bipolar Plate ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Phase Flow ◽  
Two Phase ◽  
Flowing Hydrogen ◽  
Flow Effects

A proton exchange membrane fuel cell (PEMFC) must maintain a balance between the hydration level required for efficient proton transfer and excess liquid water that can impede the flow of gases to the electrodes where the reactions take place. Therefore, it is critically important to understand the two-phase flow of liquid water combined with either the co-flowing hydrogen (anode) or air (cathode) streams. In this paper, we describe the design of an in-situ test apparatus that enables investigation of two-phase channel flow within PEMFCs, including the flow of water from the porous gas diffusion layer (GDL) into the channel gas flows; the flow of water within the bipolar plate channels themselves; and the dynamics of flow through multiple channels connected to common manifolds which maintain a uniform pressure differential across all possible flow paths. These two-phase flow effects have been studied at relatively low operating temperatures under steady-state conditions and during transient air purging sequences.

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