06/00954 Highly water-proof coating of gas flow channels by plasma polymerization for PEM fuel cells

Transients have utmost importance in the lifetime and performance degradation of PEM fuel cells. Recent studies show that cyclic transients can induce hygro-thermal fatigue. In particular, the amount of water in the membrane varies significantly during transients, and determines the ionic conductivity and the structural properties of the membrane. In this work, we present three-dimensional time-dependent simulations and analysis of the transport in PEM fuel cells. U-sections of anode and cathode serpentine flow channels, anode and cathode gas diffusion layers, and the membrane sandwiched between them are modeled using incompressible Navier-Stokes equations in the gas flow channels, Maxwell-Stefan equations in the channels and gas diffusion layers, advection-diffusion-type equation for water transport in the membrane and Ohm’s law for ionic currents in the membrane and electric currents in gas diffusion electrodes. Transient responses to step changes in load, pressure and the relative humidity of the cathode are obtained from simulations, which are conducted by means of a third party finite-element package, COMSOL.

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Optimization of PEM Fuel Cell Flow Channels: Modeling Analysis and Experimental Tests

ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2013-18006 ◽

2013 ◽

Author(s):

Hong Liu ◽

Peiwen Li

Keyword(s):

Fuel Cells ◽

Fuel Cell ◽

Experimental Work ◽

Gas Flow ◽

Current Collector ◽

Pem Fuel Cell ◽

Pem Fuel Cells ◽

Flow Channel ◽

Flow Channels ◽

Modeling Analysis

The dimensions of gas flow channels and walls/ribs of PEM fuel cells are optimized using a convenient mathematical model. Experimental work for several PEM fuel cells with modeling-optimized gas flow channels was conducted, and the tested results validate the modeling work and the optimization. The model considered average mass transfer and species’ concentrations in flow channels, which allows the determination of an average concentration polarization, the humidity in anode and cathode gas channels, and thus the proton conductivity of membranes, as well as the activation polarization. An electrical circuit for the current and ion conduction is applied to analyze the ohmic losses from anode current collector to cathode current collector. The modeling computation required relatively less computational time and thus can be applied to compute a large number of cases with various flow channel designs and operating parameters for optimization analysis. Optimum ratio of the width of flow channels against the walls/ribs was found from the modeling analysis. In the experimental work, PEM fuel cells were fabricated based on the flow channel dimensions optimized from the modeling analysis. Experimental results agreed with the modeling analysis satisfactorily in respect to the comparison of V-I performance between fuel cells with several optimized designs. The model is recommended as a tool for optimization design of gas flow channels for PEM fuel cells. The optimization results are of significance to the improvement of PEM fuel cell designs and performance.

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Numerical Investigation of Mass Transfer in PEM Fuel Cell with Straight Gas Flow Channels using CFD

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.36941 ◽

2021 ◽

Vol 9 (VII) ◽

pp. 2752-2759

Author(s):

Sahuar Sahu

Keyword(s):

Mass Transfer ◽

Fuel Cells ◽

Fuel Cell ◽

Gas Flow ◽

Analytical Study ◽

Cell Model ◽

Pem Fuel Cell ◽

Pem Fuel Cells ◽

Physical Factors ◽

Flow Channels

Interest in PEM fuel cells has grown rapidly in recent years because of its possible applications. The performance of PEM fuel cells is strongly affected by various physical factors, such as the flow of reactant gas, thermal management and water management. The performance and characteristics of a PEM fuel cell have been analysed through the development of a 3D model and numerical simulation. The result obtained from the computational model shows details of species movement, charge Transport and mass transfer phenomena. This paper also investigates the influence of input parameters on the output of the PEM fuel cell model. The result from the analytical study is compared with experimental results to check the accuracy of the model.

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Experimental and Numerical Assessment of Liquid Water Exhaust Performance of Flow Channels in PEM Fuel Cells

Transactions of the Korean Society of Mechanical Engineers B ◽

10.3795/ksme-b.2009.33.2.85 ◽

2009 ◽

Vol 33 (2) ◽

pp. 85-92 ◽

Cited By ~ 2

Author(s):

Hyun-Il Kim ◽

Jin-Hyun Nam ◽

Dong-Hoon Shin ◽

Tae-Yong Chung ◽

Young-Gyu Kim

Keyword(s):

Fuel Cells ◽

Liquid Water ◽

Pem Fuel Cells ◽

Flow Channels ◽

Numerical Assessment

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

ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2014-6507 ◽

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.

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