Modeling of Convective Heat and Mass Transfer Characteristics of Anode-Supported Planar Solid Oxide Fuel Cells

2006 ◽  
Vol 4 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Y. N. Magar ◽  
R. M. Manglik
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Porous Layer ◽  
Reaction Rate ◽  
Electrochemical Reaction ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cross Sectional ◽  
Flow Duct

Convective heat and mass transfer in a planar, trilayer, solid oxide fuel cell (SOFC) module is considered for a uniform supply of volatile species (80%H2+20%H2O vapor) and oxidant (20%O2+80%N2) to the electrolyte surface with a uniform electrochemical reaction rate. The coupled heat and mass transfer is modeled by steady incompressible fully developed laminar flow in the interconnect ducts of rectangular cross sections for both the anode-side fuel and cathode-side oxidant flows. The governing three-dimensional mass, momentum, energy, species transfer, and electrochemical kinetics equations are solved computationally. The homogeneous porous-layer flow, which is in thermal equilibrium with the solid matrix, is coupled with the electrochemical reaction rate to properly account for the flow-duct and anode/cathode interface heat/mass transfer. Parametric effects of the rectangular flow-duct cross-sectional aspect ratio and anode porous-layer thickness on the variations in temperature and mass/species distributions, flow friction factor, and convective heat transfer coefficient are presented. The thermal and hydrodynamic behavior is characterized for effective convective cooling performance, and interconnect channels of cross-sectional aspect ratio of ∼2-3 along with relative anode porous-layer thickness of ∼0.5-1.5 are seen to provide optimal thermal management and species mass transport benefits in the SOFC module.

Heat and Mass Transfer in Planar Anode-Supported Solid Oxide Fuel Cells: Effects of Interconnect Fuel/Oxidant Channel Flow Cross Section

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Raj M. Manglik ◽  
Yogesh N. Magar
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Reaction Rate ◽  
Three Dimensional ◽  
Bipolar Plate ◽  
Solid Oxide ◽  
Electrochemical Kinetics ◽  
Solid Matrix ◽  
Oxide Fuel ◽  
Transfer Coefficients

Heat and mass transfer in a planar anode-supported solid oxide fuel cell (SOFC) module, with bipolar-plate interconnect flow channels of different shapes are computationally simulated. The electrochemistry is modeled by uniform supply of volatile species (moist hydrogen) and oxidant (air) to the electrolyte surface with constant reaction rate via interconnect channels of rectangular, trapezoidal, and triangular cross sections. The governing three-dimensional equations for fluid mass, momentum, energy, and species transport, along with those for electrochemical kinetics, where the homogeneous porous-layer flow is in thermal equilibrium with the solid matrix, are coupled with the electrochemical reaction rate to properly account for the heat and mass transfer across flow-ducts and electrode-interfaces. The results highlight effects of interconnect duct shapes on lateral temperature and species distributions as well as the attendant frictional losses and heat transfer coefficients. It is seen that a relatively shallow rectangular duct offers better heat and mass transfer performance to affect improved thermal management of a planar SOFC.

Convective heat and mass transfer to a cylinder sheathed by a porous layer

AIChE Journal ◽  
2003 ◽  
Vol 49 (12) ◽  
pp. 3018-3028 ◽  
Author(s):  
Michal P. Sobera ◽  
Chris R. Kleijn ◽  
Harry E. A. Van den Akker ◽  
Paul Brasser
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Porous Layer

Numerical Analysis of Heat/Mass Transfer and Electrochemical Reaction in an Anode-Supported Flat-Tube Solid Oxide Fuel Cell

2006 ◽  
Author(s):  
Masayuki Suzuki ◽  
Naoki Shikazono ◽  
Koji Fukagata ◽  
Nobuhide Kasagi
Keyword(s):  
Mass Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Electrochemical Reaction ◽  
Cell Model ◽  
Flow Direction ◽  
Three Dimensional ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flat Tube

Three-dimensional heat and mass transfer and electrochemical reaction in an anode-supported flat-tube solid oxide fuel cell (FT-SOFC) are studied. Transport and reaction phenomena mainly change in the streamwise direction. Exceptionally, hydrogen and water vapor have large concentration gradients also in the cross section perpendicular to the flow direction, because of the insufficient mass diffusion in the porous anode. Based on these results, we develop a simplified one-dimensional cell model. The distributions of temperature, current, and overpotential predicted by this model show good agreement with those obtained by the full three-dimensional simulation. We also investigate the effects of pore size, porosity and configuration of the anode on the cell performance. Extensive parametric studies reveal that, for a fixed three-phase boundary (TPB) length, rough material grains are preferable to obtain higher output voltage. In addition, when the cell has a thin anode with narrow ribs, drastic increase in the volumetric power density can be achieved with small voltage drop.

Parallel Manifold Effects on the Heat and Mass Transfer Characteristics of Metal-Supported Solid Oxide Fuel Cell Stacks

2011 ◽  
Vol 8 (6) ◽  
Author(s):  
Joonguen Park ◽  
Joongmyeon Bae
Keyword(s):  
Mass Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Heat And Mass Transfer ◽  
Current Density ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Bottom Cell ◽  
Average Current ◽  
The Cross

The metal-supported solid oxide fuel cell (SOFC) was introduced as a new fuel cell design because it provides high mechanical strength and blocks gas leakage. Ordinary SOFCs should be manufactured in a stack because a single cell does not have sufficient capacity for a commercial system. In a stack, heat and mass transfer, which affects the performance, is altered by manifold structures. Therefore, this paper studied three kinds of manifold designs using numerical analyses. Governing equations and electrochemical reaction models were calculated simultaneously to conduct multiphysics simulations. Molecular diffusion and Knudsen diffusion were considered together to predict gas diffusion in a porous medium. Simulation results were compared with experimental data to validate the numerical code. There was a high current density with a high partial pressure of reactant gas on the hydrogen inlet and at the point where the hydrogen channel and the air channel intersected. The average current density of a cross-co flow design was 4890.5 A/m2, which was higher than the other designs used in this study. The average current densities of the cross-counter flow design and the cross flow design were 4689.1 and 4111.8 A/m2, respectively. The maximum pressure was 750 Pa in the air manifold and 32 Pa in the hydrogen manifold. The temperature of the bottom cell was lower than the top cell because the bottom cell had little exothermic heat by low polarization.

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