Nima Ahmadi; Sajad Rezazadeh; Abdolrahman Dadvand; Iraj Mirzaee
Abstract
A three-dimensional computational fluid dynamics model of a proton exchange membrane fuel cell (PEMFC) with both gas distribution flow channels and Membrane Electrode Assembly (MEA) is developed. A set of conservation equation is numerically solved by developing a CFD code based on the finite volume ...
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A three-dimensional computational fluid dynamics model of a proton exchange membrane fuel cell (PEMFC) with both gas distribution flow channels and Membrane Electrode Assembly (MEA) is developed. A set of conservation equation is numerically solved by developing a CFD code based on the finite volume technique and SIMPLE algorithm. In this research, some parameters like oxygen consumption, water production, velocity distribution, liquid water activity and the fuel cell performance for conventional cases (base Cases) are presented and compared to those in cases with semicircular prominences. The numerical simulations indicated that prominent gas diffusion layer (GDL) could improve the transport of the species through the porous layers and this leads to increment in fuel cell performance. Hence, prominent gas diffusion layers would result in higher current density. Finally the numerical results for the base Cases were compared with the experimental data, which represented reasonable agreement.
Ashkan Torkavannejad; S. Mehdi Pesteei; Farzin Ramin; Nima Ahmadi; Hadi Shahmohammadi
Abstract
In this research, the impact of shoulder width and geometry of gas channel with different structures on proton exchange membrane (PEM) has been investigated using numerical method. 3D, non-isothermal was used with single straight channel geometrywhile maintaining the same boundary conditions and reaction ...
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In this research, the impact of shoulder width and geometry of gas channel with different structures on proton exchange membrane (PEM) has been investigated using numerical method. 3D, non-isothermal was used with single straight channel geometrywhile maintaining the same boundary conditions and reaction area with addition of humidification for anode and cathode. Our study showed that an elliptical and circular channel cross-section gave higher current density as compared with conventional model. Moreover, the elliptical and circular channel configurations facilitated reactant transportation, caused more homogenous distribution of reactants andeffectively reduced mass transport loss, which lowered cathode overpotential of the cell which is the main cause of loss. Simulation of the three different channel geometries revealed that shoulder width has dominating effect on cell performance and leads to increase the value of Ohmicloss. The numerical model is validated against published experimental data and shows good agreement. Additional results with more detail are discussed and presented in the text.
Sajad Alah Rezazadeh; Iraj Mirzaie; Nader Pourmahmoud; Nima Ahmadi
Abstract
A full three-dimensional, single phase computational fluid dynamics model of a proton exchange membrane fuel cell (PEMFC) with both the gas distribution flow channels and the Membrane Electrode Assembly (MEA) has been developed. A single set of conservation equations which are valid for the flow channels, ...
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A full three-dimensional, single phase computational fluid dynamics model of a proton exchange membrane fuel cell (PEMFC) with both the gas distribution flow channels and the Membrane Electrode Assembly (MEA) has been developed. A single set of conservation equations which are valid for the flow channels, gas-diffusion electrodes, catalyst layers, and the membrane region are developed and numerically solved using a finite volume based computational fluid dynamics technique. In this research some parameters such as oxygen consumption, water production, temperature distribution, ohmic losses, anode water activity, cathode over potential and the fuel cell performance for straight single cell were investigated in more details. The numerical simulations reveal that these important operating parameters are highly dependent to each other and the fuel cell efficiency is affected by the kind of species distribution. So for especial uses in desirable voltages, for preventing from the unwilling losses, these numerical results can be useful. Finally the numerical results of proposed CFD model have been compared with the published experimental data that represent good agreement.
