Mechanical contact analysis on the interfaces in a proton exchange membrane fuel cell

Shang

et al. 2020

Preprint

Self Cite

The endplates are essential to assembly a large proton exchange membrane (PEM) fuel cell stack, whose deflection is negative to its uniform contact pressure distribution and large electrical contact resistance. The endplates with assembly clamping belts are proposed as an equivalent mechanical beam model consisting of elastic beam element with clamping forces. The deflection curve equations of endplates with 1 to 5 clamping belts are studied which allows investigating endplates deflection for uniform contact pressure distribution. Based on this equivalent mechanical model for fuel cell stack, the effects of the thicknesses of endplates, numbers and positions of clamping belts are discussed, and show the optimal thickness of endplate with different clamping belts, and moreover the optimal position of intermediate and outer clamping belts on the endplates. Finally, a three-dimensional finite element analysis (FEA) of a fuel cell stack clamping with steel belts and nonlinear contact elements is compared to what the equivalent mechanical beam model predicts. It is found that the presented model gives good prediction accuracy for the deflection behavior of endplates and the clamping force. Results showed that the equivalent mechanical modeling is effective and helpful for the design of a large fuel cell stack assembly.

Section: Figure 1 Schematic Of Components Of the Fuel Cell Stackmentioning

confidence: 99%

An Equivalent Mechanical Model Investigating Endplates Deflection For a Large PEM Fuel Cell Stack

Shang

et al. 2020

Preprint

Self Cite

“…The least thickness of the endplate can be obtained by this pre-curvature design. Carral et al 19,20 developed a FEA model to investigate the effect of the different numbers of cells (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) and their position on the endplates of the fuel cell stacks, the results revealed that with the greatest number of cells, a better uniformity of the contact pressure on MEA could be obtained. The deflection of endplates can be indicated the uniformity of contact pressure on the MEA.…”

Section: Introductionmentioning

confidence: 99%

An equivalent mechanical model investigating endplates deflection for PEM fuel cell stack

Shang

Advances in Mechanical Engineering

2021

Self Cite

The aim of this study is to obtain the deflection curve equations of endplates with one to five clamping belts which allows investigating endplates deflection for uniform contact pressure distribution. Based on an equivalent mechanical model for a large fuel cell stack, the effects of the thicknesses of endplates, numbers, and positions of clamping belts are discussed, and the optimal thickness of endplate with different clamping belts is obtained, and moreover the optimal position of intermediate and outer clamping belts on the endplates. Finally, a three-dimensional finite element analysis (FEA) of a fuel cell stack clamping with steel belts and nonlinear contact elements is compared to what the equivalent mechanical beam model predicts. The result of this study shows that the equivalent mechanical model gives good prediction accuracy for the deflection behavior of endplates and the clamping force of the fuel cell stack, which is effective and helpful for the design of a large fuel cell stack assembly.

“…The chemical properties of the GDL and membrane are sharply changed, which lead to eventual failure of their physical properties. Indeed, the variation of internal stresses and contact pressure between the assembly elements of a PEMFC fuel cell causes larges stains 2 . This result is produced by the changes in its mechanical, electrochemical and thermal characteristics.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of Effect of Contact Pressure on Mechanical Behavior of Gas Diffusion Layers (GDL) and PFSA Membrane Assembly

Ettouhami¹,

Atifi²,

Mounir³

et al. 2019

Mediterr.J.Chem.,

In this study, a Finite Element model has been implemented based on numerical modelling simulations to predict the mechanical behaviour of a representative unit of the fuel cell stack. The GDL deformation has been modelled as a combination of elastic deformation and fibres slippage. Mechanical stresses distribution and deformation are presented concerning the previous model work l with nonlinear orthotropic behaviour of the GDL. The results also show that the state of the stresses in the membrane are highly heterogeneous and largely exceed its elastic limit. The results show that the influence of the temperature variation is not significant in generating stresses. However, the influence of the moisture variation is very significant in generating stresses. Therefore, the increase in relative humidity from 30% to 90° % at T=25°C causes an increase in the maximum Von Mises stress of 0.0836MPa.