Modeling of inhomogeneous compression effects of porous GDL on transport phenomena and performance in PEM fuel cells

Wang, Jiatang; Yuan, Jinliang; Sundén, Bengt

doi:10.1002/er.3687

Cited by 25 publications

(10 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This work complements our previous research by taking into account the geometric deformation due to the assembly pressure. In addition, the related nonlinear change of the porosity is considered.…”

Section: Introductionsupporting

confidence: 62%

See 1 more Smart Citation

Investigation of effects of non-homogenous deformation of gas diffusion layer in a PEM fuel cell

Wang

Yuan

et al. 2017

Int J Energy Res

Self Cite

View full text Add to dashboard Cite

Summary Proton exchange membrane fuel cells have been promoted due to improved breakthrough and increased commercialization. The assembly pressure put on a single cell and a fuel cell stack has important influence on the geometric deformation of the gas diffusion layers (GDLs) resulting in a change in porosity, permeability, and the resistance for heat and charge transfer in proton exchange membrane fuel cells. In this paper, both the finite element method and the finite volume method are used, respectively, to predict the GDL deformation and associated effects on the geometric parameters, porosity, mass transport property, and the cell performance. It is found that based on the isotropic Young's modulus and the finite element method, the porosity and thickness under a certain assembly pressure are non‐homogeneous across the fuel cell in the in‐plane direction. The variations of the porosity change and compression ratio in the cross‐section plane are localized by three zones, that is, a linear porosity zone, a constant porosity zone, and a nonlinear porosity zone. The results showed that the GDL porosity and compression ratios maintain linear and nonlinear changes in the zone above the shoulders and the zone under the channel but close to the shoulder, respectively. However, a constant value is kept above the middle of the channel. The obtained non‐homogeneous porosity distribution is applied together with the deformed GDL for further computational fluid dynamics analysis, in which the finite volume method is implemented. The computational fluid dynamic results reveal that a higher assembly pressure decreases the porosity, GDL thickness, gas flow channel cross‐sectional areas, oxygen diffusion coefficient, oxygen concentration, and cell performance. The maximum oxygen mole fraction occurs where the maximum porosity exists. A sufficient GDL thickness is required to ensure transfer of fresh gas to the reaction sites far away from the channel. However, the reduction of porosity is a dominating factor that decreases the cell performance compared with the decreased gas channel flow area and GDL thickness in the assembly condition. Therefore, the assembly pressure should be balanced to consider both the cell performance and gas sealing security. Copyright © 2017 John Wiley & Sons, Ltd.

show abstract

Section: Introductionsupporting

confidence: 62%

“…A number of assumptions are made in the numerical CFD model in this study. These assumptions are identical to those in our previous work except the one related to the porosity change. The porosity is kept constant in the GDL above the channels but changes above the shoulders due to the compression in that work.…”

Section: Modeling Descriptionmentioning

confidence: 90%

Investigation of effects of non-homogenous deformation of gas diffusion layer in a PEM fuel cell

Wang

Yuan

et al. 2017

Int J Energy Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…Liquid saturation in the CL increases when the RH increases (Figures and ). This causes a decrease in the effective diffusion coefficient as the water blocks the pores of the GDL . In fact, by increasing liquid saturation, the mass transfer resistance increases, and therefore the oxygen concentration in the CL decreases.…”

Section: Resultsmentioning

confidence: 99%

Effects of an MPL on water and thermal management in a PEMFC

2018

View full text Add to dashboard Cite

Summary In this study, the effects of adding a microporous layer (MPL) as well as the impact of its physical properties on polymer electrolyte fuel cell (PEMFC) performance with serpentine flow channels were investigated. In addition, numerical simulations were performed to reveal the effect of relative humidity and operating temperature. It is indicated that adding an extra between the gas diffusion layer (GDL) and catalyst layer (CL), a discontinuity in the liquid saturation shows up at their interface because of differences in the wetting properties of the layers. In addition, results show that a higher MPL porosity causes the liquid water saturation to decrease and the cell performance is improved. A larger MPL thickness reduces the cell performance. The effects of MPL on temperature distribution and thermal transport of the membrane prove that the MPL in addition to being a water management layer also improves the thermal management of the PEMFC.

show abstract

“…Therefore, we assume that the applied clamping force results only in the deformation of pore volume of gas diffusion layers while the solid volume remains constant, as shown in Figure , reducing the pore volume directly decreasing the GDLs porosity. In addition, the GDL intrusion into the channels is neglected in this investigation and will be considered in future work.…”

Section: Numerical Modelmentioning

confidence: 99%

Effects of Clamping Pressure on Cold Start Behavior of Polymer Electrolyte Fuel Cells

et al. 2019

View full text Add to dashboard Cite

Understanding the cold start process of polymer electrolyte fuel cell (PEFC) is crucial to the development of an advanced PEFC of good cold start performance or to the design of advanced cold start strategies. In this study, a three‐dimensional cold start model has been adapted and further developed to numerically investigate the cold start behavior under the applied clamping pressure, which was not considered in previous cold start modeling and simulation work. The PEFC cold start performance is studied under various assembly pressures in terms of polarization curves, ice formation, water content profile, and current density distribution, etc. The results indicate that, using a large clamping pressure leads to a significant decline on the cold start performance; therefore, using an optimum clamping pressure is important to obtain a better cold start performance. It is found that increasing the clamping pressure not only increases the ice accumulation in cathode catalyst layer, but also causes the dehydration of membrane and decreases the cold start performance. The proposed model can be used as a powerful tool to study the realistic cold start performance of PEFC and to assist the development of more advanced PEFC cold start strategies.

show abstract

Modeling of inhomogeneous compression effects of porous GDL on transport phenomena and performance in PEM fuel cells

Cited by 25 publications

References 37 publications

Investigation of effects of non-homogenous deformation of gas diffusion layer in a PEM fuel cell

Investigation of effects of non-homogenous deformation of gas diffusion layer in a PEM fuel cell

Effects of an MPL on water and thermal management in a PEMFC

Effects of Clamping Pressure on Cold Start Behavior of Polymer Electrolyte Fuel Cells

Contact Info

Product

Resources

About