A critical review of two-phase flow in gas flow channels of proton exchange membrane fuel cells

Anderson, Ryan; Zhang, Lifeng; Ding, Yulong; Blanco, Mauricio; Bi, Xiaotao; Wilkinson, David P.

doi:10.1016/j.jpowsour.2009.12.123

Cited by 238 publications

(120 citation statements)

References 151 publications

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“…The power-law exponents have been shown to have values of around 3 for typical fibrous GDLs, 41,42,44,145 [72] and are anisotropic with the in-plane value being several times larger than the through-plane one, which also agrees with microscopic modeling results. 146,147 For the bulk movement and convection of the gas phase, Darcy's law and the mass-averaged velocity (equations 42 and 13, respectively) are used with an effective permeability that is comprised of the absolute (measured) permeability and a relative permeability owing to the impact of liquid [73] where k r,k is the relative permeability for phase k and is often given by a power-law dependence on the saturation.…”

Section: Multiphase Flowsupporting

confidence: 80%

“…Although straightforward for single-phase conditions, a two-phase pressure differential correlation is required once the flow distributor condition exceeds 100% RH. [72][73][74][75] Additionally, PEFC systems typically operate with hydrogen stoichiometric ratios greater than 1.0, thereby requiring a methodology for recirculating exhaust anode flow. In this case the nitrogen and water content in the anode flow distributor due to crossover through the membrane must be accounted for as the diluted hydrogen feed stream will impact performance.…”

Section: Journal Of the Electrochemical Society 161 (12) F1254-f1299mentioning

confidence: 99%

“…Once in the channel, the water moves either along the walls, as a mist, or stochastically by forming films that are periodically removed due to gas-pressure buildup. 72,251,252 The key conditions for this boundary condition are being able to predict the surface coverage of water or droplets and the subsequent capillary pressure or liquid pressure as a function of material properties and operating conditions. This is something that has been researched both theoretically and experimentally, but not yet clarified and utilized, especially in PEFC cell modeling.…”

mentioning

confidence: 99%

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A Critical Review of Modeling Transport Phenomena in Polymer-Electrolyte Fuel Cells

Weber

Borup

Darling³

et al. 2014

J. Electrochem. Soc.

509

394

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Polymer-electrolyte fuel cells are a promising energy-conversion technology. Over the last several decades significant progress has been made in increasing their performance and durability, of which continuum-level modeling of the transport processes has played an integral part. In this review, we examine the state-of-the-art modeling approaches, with a goal of elucidating the knowledge gaps and needs going forward in the field. In particular, the focus is on multiphase flow, especially in terms of understanding interactions at interfaces, and catalyst layers with a focus on the impacts of ionomer thin-films and multiscale phenomena. Overall, we highlight where there is consensus in terms of modeling approaches as well as opportunities for further improvement and clarification, including identification of several critical areas for future research. Fuel cells may become the energy-delivery devices of the 21 st century. Although there are many types of fuel cells, polymer-electrolyte fuel cells (PEFCs) are receiving the most attention for automotive and small stationary applications. In a PEFC, fuel and oxygen are combined electrochemically. If hydrogen is used as the fuel, it oxidizes at the anode releasing proton and electrons according toThe generated protons are transported across the membrane and the electrons across the external circuit. At the cathode catalyst layer, protons and electrons recombine with oxygen to generate waterAlthough the above electrode reactions are written in single step, multiple elementary reaction pathways are possible at each electrode. During the operation of a PEFC, many interrelated and complex phenomena occur. These processes include mass and heat transfer, electrochemical reactions, and ionic and electronic transport. * Electrochemical Society Active Member. z E-mail: azweber@lbl.govOver the last several decades significant progress has been made in increasing PEFC performance and durability. Such progress has been enabled by experiments and computation at multiple scales, with the bulk of the focus being on optimizing and discovering new materials for the membrane-electrode-assembly (MEA), composed of the proton-exchange membrane (PEM), catalyst layers, and diffusionmedia (DM) backing layers. In particular, continuum modeling has been invaluable in providing understanding and insight into processes and phenomena that cannot be resolved or uncoupled through experiments. While modeling of the transport and related phenomena has progressed greatly, there are still some critical areas that need attention. These areas include modeling the catalyst layer and multiphase phenomena in the PEFC porous media.While there have been various reviews over the years of PEFC modeling 1-7 and issues, [8][9][10][11][12][13][14] as well as numerous books and book chapters, there is a need to examine critically the field in terms of what has been done and what needs to be done. This review serves that purpose with a focus on transport modeling of PEFCs. This is not meant to be an exhaustive review...

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Section: Multiphase Flowsupporting

confidence: 80%

Section: Journal Of the Electrochemical Society 161 (12) F1254-f1299mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

A Critical Review of Modeling Transport Phenomena in Polymer-Electrolyte Fuel Cells

Weber

Borup

Darling³

et al. 2014

J. Electrochem. Soc.

509

394

View full text Add to dashboard Cite

show abstract

“…However, to a large extent, the performance is dependent on the hydration of the polymer membrane, where the water balance is dependent on the fuel cell current and water content of fuel and oxidant gas stream [24]. When the current density goes beyond a certain threshold, the delivery of water by electro-osmotic drag and oxygen-reduction reaction (ORR) overtakes the water removal from the cathode catalyst [25] hence, the excess water accumulates, flooding the electrode and reducing the rate of oxygen being transported to the catalyst.…”

Section: Water Managementmentioning

confidence: 99%

A Review of Computational Fluid Dynamics Simulations on PEFC Performance

Chen¹,

Enearu²,

Montalvão³

et al. 2016

J Appl Mech Eng

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Among the number of fuel cells in existence, the proton exchange fuel cell (PEFC) has been favoured because of its numerous applications. These applications range from small power generation in cell phones, to stationary power plants or vehicular applications. However, the principle of operation on PEFCs naturally leads to the development of water from the reaction between hydrogen and oxygen. Computational fluid dynamics (CFD) has played an important role in many research and development projects. From automotive to aerospace and even medicine, to the development of fuel cells, by making it possible to investigate different scenarios and fluid flow patterns for optimal performance. CFD allows for in-situ analysis of PEFCs, by studying fluid flow and heat and mass transfer phenomena, thus reducing the need for expensive prototypes and cutting down test-time by a substantial amount. This paper aims at investigating the advances made in the use of CFD as a technique for the performance and optimisation of PEFCs to identify the research and development opportunities in the field, such as the performance of a novel PEFC, with focus on the underlying physics and in-situ analysis of the operations.

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“…Understanding, designing and optimizing flows is crucial, e.g., for improving fuel injections [1], combustions [2,3], fuel cells [4], wind turbines [5], turbomachines [6], human air and blood flows in medicine [7,8], as well as for the fundamental task of modeling flow turbulence [9]. For this purpose, optical measurement methods are essential tools that promise fast and precise field measurements of complex flows.…”

Section: Introductionmentioning

confidence: 99%

Imaging Flow Velocimetry with Laser Mie Scattering

Fischer

2017

Applied Sciences

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Abstract:Imaging flow velocity measurements are essential for the investigation of unsteady complex flow phenomena, e.g., in turbomachines, injectors and combustors. The direct optical measurement on fluid molecules is possible with laser Rayleigh scattering and the Doppler effect. However, the small scattering cross-section results in a low signal to noise ratio, which hinders time-resolved measurements of the flow field. For this reason, the signal to noise ratio is increased by using laser Mie scattering on micrometer-sized particles that follow the flow with negligible slip. Finally, the ongoing development of powerful lasers and fast, sensitive cameras has boosted the performance of several imaging methods for flow velocimetry. The article describes the different flow measurement principles, as well as the fundamental physical measurement limits. Furthermore, the evolution to an imaging technique is outlined for each measurement principle by reviewing recent advances and applications. As a result, the progress, the challenges and the perspectives for high-speed imaging flow velocimetry are considered.

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A critical review of two-phase flow in gas flow channels of proton exchange membrane fuel cells

Cited by 238 publications

References 151 publications

A Critical Review of Modeling Transport Phenomena in Polymer-Electrolyte Fuel Cells

A Critical Review of Modeling Transport Phenomena in Polymer-Electrolyte Fuel Cells

A Review of Computational Fluid Dynamics Simulations on PEFC Performance

Imaging Flow Velocimetry with Laser Mie Scattering

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