Fuel Cell Stack, Bipolar Plate, and Gas Flow Channel

Fuel Cells ◽  
2016 ◽  
pp. 440-485
Author(s):  
Kenneth J. Kelly ◽  
Gregory C. Pacifico ◽  
Michael Penev ◽  
Andreas Vlahinos

The National Renewable Energy Laboratory (NREL) and Plug Power Inc. have been working together to develop fuel cell modeling processes to rapidly assess critical design parameters and evaluate the effects of variation on performance. This paper describes a methodology for investigating key design parameters affecting the thermal performance of a high temperature, polybenzimidazole (PBI)-based fuel cell stack. Nonuniform temperature distributions within the fuel cell stack may cause degraded performance, induce thermo-mechanical stresses, and be a source of reduced stack durability. The three-dimensional (3-D) model developed for this project includes coupled thermal/flow finite element analysis (FEA) of a multi-cell stack integrated with an electrochemical model to determine internal heat generation rates. Sensitivity and optimization algorithms were used to examine the design and derive the best choice of the design parameters. Initial results showed how classic design-of-experiment (DOE) techniques integrated with the model were used to define a response surface and perform sensitivity studies on heat generation rates, fluid flow, bipolar plate channel geometry, fluid properties, and plate thermal material properties. Probabilistic design methods were used to assess the robustness of the design in response to variations in load conditions. The thermal model was also used to develop an alternative coolant flow-path design that yields improved thermal performance. Results from this analysis were recently incorporated into the latest Plug Power coolant flow-path design. This paper presents an evaluation of the effect of variation on key design parameters such as coolant and gas flow rates and addresses uncertainty in material thermal properties.


2018 ◽  
Vol 43 (7) ◽  
pp. 2605-2614 ◽  
Author(s):  
Kailin Fu ◽  
Tian Tian ◽  
Yanan Chen ◽  
Shang Li ◽  
Chao Cai ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Yue-Tzu Yang ◽  
Kuo-Teng Tsai ◽  
Cha’o-Kuang Chen

The objective of this study is to use a new style of waved flow channel instead of the plane surface channel in the proton exchange membrane fuel cell (PEMFC). The velocity, concentration, and electrical performance with the waved flow channel in PEMFC are investigated by numerical simulations. The results show that the waved channel arises when the transport benefits through the porous layer and improves the performance of the PEMFC. This is because the waved flow channel enhances the forced convection and causes the more reactant gas flow into the gas diffusion layer (GDL). The performance which was compared to a conventional straight gas flow channel increases significantly with the small gap size when it is smaller than 0.5 in the waved flow channel. The performance is decreased at the high and low velocities as the force convection mechanism is weakened and the reactant gas supply is insufficient. The pressure drop is increased as the gap size becomes smaller, and the wave number decreases. (gap size)δ> 0.3 has a reasonable pressure drop. Consequently, compared to a conventional PEMFC, the waved flow channel improves approximately 30% of power density.


2019 ◽  
Vol 286 ◽  
pp. 09006
Author(s):  
A. Atifi ◽  
K. El Bikri ◽  
M. Ettouhami

In this study, a two-dimensional, Finite Element model has been implemented based numerical modeling simulations to predict mechanical behavior of a representative unit of fuel cell stack deformation under three levels of contact pressure between GDL and bipolar plate assuming that the GDL deformation as a combination of elastic deformation and fibers slippage. The intrusion of the GDL into the channel was estimated. Indeed, with orthotropic behavior of the GDL, the proposed nonlinear orthotropic model converges towards the models of the literature as a function of the contact pressure level between the bipolar plate and the GDL (Gas Diffusion Layers).


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