Pore-network modeling of liquid water flow in gas diffusion layers of proton exchange membrane fuel cells

Shahraeeni, Mehdi; Hoorfar, Mina

doi:10.1016/j.ijhydene.2014.05.017

Cited by 25 publications

(12 citation statements)

References 24 publications

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“…In this study, only liquid water intrusion is studied. In addition, the assumption of constant contact angle has been widely used to study two-phase flows in GDLs [35][36][37][38][39][40][41][42][43][44][45][46][47][48]53,54,56].…”

Section: Initial and Boundary Conditions (A) Two-phase Vof Modelmentioning

confidence: 99%

“…As in other technological branches, numerical simulations are expected to help understand the complex liquid water behaviors in GDLs via various multiphase models such as the multiphase mixture (M 2 ) model [31][32][33][34][35], Lattice Boltzmann (LB) model [36][37][38][39], pore network (PN) model [40][41][42] and volume of fluid (VOF) model [43][44][45][46][47][48]. Wang and Chen [31] employed a M 2 model to elucidate water distribution in the through-plane (TP) direction of the GDL and validate their results with high-resolution neutron imaging data.…”

Section: Introductionmentioning

confidence: 99%

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Two-phase flow and oxygen transport in the perforated gas diffusion layer of proton exchange membrane fuel cell

Niu

Bao

et al. 2019

International Journal of Heat and Mass Transfer

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Liquid water transport in perforated gas diffusion layers (GDLs) is numerically investigated using a threedimensional (3D) two-phase volume of fluid (VOF) model and a stochastic reconstruction model of GDL microstructures. Different perforation depths and diameters are investigated, in comparison with the GDL without perforation. It is found that perforation can considerably reduce the liquid water level inside a GDL. The perforation diameter (D = 100 lm) and the depth (H = 100 lm) show pronounced effect. In addition, two different perforation locations, i.e. the GDL center and the liquid water breakthrough point, are investigated. Results show that the latter perforation location works more efficiently. Moreover, the perforation perimeter wettability is studied, and it is found that a hydrophilic region around the perforation further reduces the water saturation. Finally, the oxygen transport in the partially-saturated GDL is studied using an oxygen diffusion model. Results indicate that perforation reduces the oxygen diffusion resistance in GDLs and improves the oxygen concentration at the GDL bottom up to 101% (D = 100 lm and H = 100 lm).

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Section: Initial and Boundary Conditions (A) Two-phase Vof Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Two-phase flow and oxygen transport in the perforated gas diffusion layer of proton exchange membrane fuel cell

Niu

Bao

et al. 2019

International Journal of Heat and Mass Transfer

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“…21,24,47 But, this feature is not implemented in the present pore-network model. In the case studies of unsaturated GC, we vary the RH value in the GC to investigate its effect on the water transport in the GDL.…”

Section: Description Of Numerical Simulationsmentioning

confidence: 99%

Water Transport in the Gas Diffusion Layer of a Polymer Electrolyte Fuel Cell: Dynamic Pore-Network Modeling

Qin¹

2015

J. Electrochem. Soc.

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The pore-scale modeling is a powerful tool for increasing our understanding of water transport in the fibrous gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). In this work, a new dynamic pore-network model for air-water flow in the GDL is developed. It incorporates water vapor transport coupled with liquid water by a phase change model. One important feature of our pore-network model is that a recently developed semi-implicit scheme for the update of water saturation is used. It provides good numerical stability in modeling liquid water transport in the GDL even for very small capillary number values. A number of case studies are conducted to illustrate several important mechanisms of water transport in the GDL, such as cyclic processes of local drainage and imbibition, channeling and capillary-fingering evolutions of water flow pattern, and eruptive water transport. Moreover, we show that liquid water separation in the GDL between the ribs and gas channel (GC) is formed under dry GC condition, which is qualitatively in agreement with in situ experimental results. Water management plays an important role in the durability and performance of polymer electrolyte fuel cells (PEFCs). A delicate water balance must be maintained to keep the membrane hydrated and at the same time avoid liquid water flooding in the porous components. [1][2][3] Over the past two decades, numerous studies have been conducted for improving our understanding of water transport mechanisms within the PEFC. Compared to the anode side, water transport in the cathode has usually attracted more attention. This is because the cathode is prone to being flooded first, and the oxygen reduction reaction (ORR) is very sluggish. The fibrous gas diffusion layer (GDL), as a key component, plays an important role in removing excessive water from the catalyst layer (CL) to the gas channel (GC). Up to now, much effort has been invested in gaining insights into pore-scale processes of liquid water transport in the GDL. [4][5][6][7][8][9][10] Despite the great success in in situ observations of water distribution, 8,9,[11][12][13][14] water dynamics in the GDL is still not well understood. Also, the cost of those experiments is quite high. This has stimulated many pore-scale numerical studies of the GDL over the past few years. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] Several distinctive features of liquid water transport in the GDL make its pore-scale modeling extremely difficult. First, a small flow rate of liquid water, with a capillary number value of around 10 −8 , causes the modeling computationally expensive. Second, the complexity 34 of the pore structure and mixed wettability of the GDL give rise to the difficulty in developing an elegant pore-scale model. Nevertheless, many achievements still have been booked.Mukherjee et al. 4 were the first to conduct the Lattice-Boltzmann modeling of air-water flow in a stochastically reconstructed nonwoven GDL. The authors illustrated the structure-wettabili...

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“…Alternatively, several two-phase models have been proposed to predict water dynamics and distribution such as the multiphase mixture (M 2 ) model, [11][12][13][14][15] lattice Boltzmann method (LBM), [16][17][18][19][20] pore network method (PNM) [21][22][23] and volume of fluid (VOF) method. [24][25][26] Pasaogullari et al 11 presented a M 2 model to predict liquid water profile across the GDL.…”

mentioning

confidence: 99%

Two-Phase Flow Dynamics in the Gas Diffusion Layer of Proton Exchange Membrane Fuel Cells: Volume of Fluid Modeling and Comparison with Experiment

Niu

Wang

Jiao

et al. 2018

J. Electrochem. Soc.

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This paper proposes a three-dimensional (3D) volume of fluid (VOF) study to investigate two-phase flow in the gas diffusion layer (GDL) of proton exchange membrane (PEM) fuel cells and liquid water distribution. A stochastic model was adopted to reconstruct the 3D microstructures of Toray carbon papers and incorporate the experimentally-determined varying porosity. The VOF predictions were compared with the water profiles obtained by the X-ray tomographic microscopy (XTM) and the Leverett correlation. It was found local water profiles are similar in the sample's sub-regions under the pressure difference p = 1000 Pa between the two GDL surfaces, but may vary significantly under p = 6000 Pa. The water-air interfaces inside the GDL structure were presented to show water distribution and breakthrough.

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Pore-network modeling of liquid water flow in gas diffusion layers of proton exchange membrane fuel cells

Cited by 25 publications

References 24 publications

Two-phase flow and oxygen transport in the perforated gas diffusion layer of proton exchange membrane fuel cell

Two-phase flow and oxygen transport in the perforated gas diffusion layer of proton exchange membrane fuel cell

Water Transport in the Gas Diffusion Layer of a Polymer Electrolyte Fuel Cell: Dynamic Pore-Network Modeling

Two-Phase Flow Dynamics in the Gas Diffusion Layer of Proton Exchange Membrane Fuel Cells: Volume of Fluid Modeling and Comparison with Experiment

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