Effect of gas flow rates and Boudouard reactions on the performance of Ni/YSZ anode supported solid oxide fuel cells with solid carbon fuels

2011 ◽  
Vol 196 (10) ◽  
pp. 4719-4723 ◽  
Author(s):  
Andrew C. Chien ◽  
Steven S.C. Chuang
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Gas Flow ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Solid Carbon ◽  
Flow Rates

Simulation of Surface Reactions and Multiscale Transport Processes in a Composite Anode Domain Relevant for Solid Oxide Fuel Cells

2013 ◽  
Vol 10 (2) ◽  
Author(s):  
Jinliang Yuan ◽  
Guogang Yang ◽  
Bengt Sunden
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Gas Phase ◽  
Gas Flow ◽  
Surface Reactions ◽  
Transport Processes ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Internal Reforming ◽  
Reforming Reactions

There are various transport phenomena (gas-phase species, heat, and momentum) occurring at different length scales in anode-supported solid oxide fuel cells (SOFCs), which are strongly affected by catalytic surface reactions at active triple-phase boundaries (TPBs) between the void space (for gas), Ni (catalysts for electrons), and YSZ (an electrolyte material for ions). To understand the multiscale chemical-reacting transport processes in the cell, a three-dimensional numerical calculation approach (the computational fluid dynamics (CFD) method) is further developed and applied for a composite domain including a porous anode, fuel gas flow channel, and solid interconnect. By calculating the rate of microscopic surface-reactions involving the surface-phase species, the gas-phase species/heat generation and consumption related to the internal reforming reactions have been identified and implemented. The applied microscopic model for the internal reforming reactions describes the adsorption and desorption reactions of six gas-phase species and surface reactions of 12 surface-adsorbed species. The predicted results are presented and analyzed in terms of the gas-phase species and temperature distributions and compared with those predicted by employing the global reaction scheme for the internal reforming reactions.

The effect of fuel gas mixtures and air flow rates on electrical properties of solid oxide fuel cell

2021 ◽  
Vol 2021 (3) ◽  
pp. 119-126
Author(s):  
N. O. Lysunenko ◽  
◽  
Y. M. Brodnikovskyi ◽  
V. I. Chedryk ◽  
D. M. Brodnikovskyi ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Electrical Properties ◽  
Solid Oxide Fuel Cell ◽  
Gas Flow ◽  
Optimal Operation ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flow Rates ◽  
Model Fuel

Fuel Cells are one of the most efficient and environmentally friendly devices for electricity generation, which are developing rapidly and are already in the early stages of commercialization. Solid Oxide Fuel Cells (SOFC) areone of the most promising their types due to the highest efficiency, fuel flexibility (H2, CnHm, CO etc.) and no needs in platinum group catalysts. The performance of SOFC is affected by various polarization losses, which aredependant on selected materials, their structure and SOFC operation parameters. Over the last decade, much attention is given to the study of SOFC’s electrochemical properties at different operating regimes: temperatures, fuels, fuel and oxidantflow rates etc. The work is devoted to studying the influence of the model fuel (5% H2—Ar) and air (oxidant) flow rates on electrical properties of Solid Oxide Fuel Cellat 800 °C to determine the best combination of gas flow rates, which provide the maximum values of specific electric power. The fuel (0,35 l/min) and oxidant (1 l/min)flow rates was found as the optimal operation regime of fuel and air supply for the SOFC tested. The highest electrical densityto be ensured by the model fuel was determined as 34 mW/cm2. The amount / flow rate of oxidant and fuel gases supplied to the fuel cell does not correspond to the ratio of the reagents of the chemical reaction of oxidation of the fuel. This difference is explained by the fact that the SOFC effectiveness of fuel and oxidant utilization depends not only from to the properties structure and materials of each components: anode, cathode, electrolyte, but also from concentration of fuel and oxidant in model fuel or air, which also creates a barrier for oxidant and fuel molecules to reach the reaction zone. Keywords: Solid Oxide Fuel Cell, electrical properties, fuelgasmixtures, hydrogen, oxidant.

Mass/Charge Transfer in Mono-Block-Layer-Built-Type Solid-Oxide Fuel Cells

2005 ◽  
Vol 2 (3) ◽  
pp. 164-170 ◽  
Author(s):  
J. J. Hwang
Keyword(s):  
Fuel Cells ◽  
Charge Transfer ◽  
Solid Oxide Fuel Cells ◽  
Gas Flow ◽  
Average Pore Size ◽  
Porous Electrodes ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Average Pore ◽  
Block Layer

The mass/charge transfer characteristics in a simulated MOLB (mono-block-layer built)-type solid-oxide fuel cells have been studied numerically. The transport phenomena within a linear MOLB module, including flow channels, active porous electrodes, electrolyte, and interconnections, are simulated using the finite volume method. The gas flow in the porous electrodes is governed by the isotropic linear resistance model with constant porosity and permeability. The diffusions of reactant species in the porous electrodes are described by the Stefan-Maxwell relation. Effective diffusivities for porous layers follow the Bruggman model. Porous electrochemistry is depicted via surface reactions with a constant surface-to-volume ratio, tortuosity, and average pore size. Results of the cathode-supported cell and the anode-supported cell are obtained, discussed, and compared thereafter for the first time.

Solid Oxide Fuel Cells in Unmanned Undersea Vehicle Applications

2006 ◽  
Vol 973 ◽  
Author(s):  
Louis George Carreiro ◽  
A. Alan Burke
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Flow Rates ◽  
Reformate Gas ◽  
Stable Performance ◽  
Undersea Vehicle ◽  
Battery Technology

ABSTRACTThe Navy is currently investigating solid oxide fuel cells (SOFCs) for the propulsion of unmanned undersea vehicles (UUVs). SOFCs are being targeted because of their potential to carry out extended missions, which are not possible using current battery technology. In addition, they offer the advantages of being able to utilize energy-dense hydrocarbon fuels and are self-sustaining while supplying heat to reforming processes.The SOFC system evaluated in this study consisted of a Ni-YSZ-based, 6-cell stack with anode supported cells close-coupled with a micro-channel steam reformer. Various reformate gas compositions, steam to carbon ratios and flow rates were tested to gather a range of data under the expected operating conditions of UUVs. The system was operated for more than 70 hours consuming approximately 0.5 to 0.7 ml/min of fuel and producing about 100 to 230 watts of power. The integrated stack and reformer displayed stable performance with a fuel utilization of 80% and an efficiency of 50% at maximum power output.

Influence of Gas Flow Rate on Performance of H[sub 2]S/Air Solid Oxide Fuel Cells with MoS[sub 2]-NiS-Ag Anode

2003 ◽  
Vol 150 (4) ◽  
pp. A463 ◽  
Author(s):  
G. L. Wei ◽  
M. Liu ◽  
J. L. Luo ◽  
A. R. Sanger ◽  
K. T. Chuang
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Flow Rate ◽  
Gas Flow ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Gas Flow Rate

Effect of an Anode Functional Layer on Cell Performance of Anode-Supported Solid Oxide Fuel Cells by a Decalcomania Method

2013 ◽  
Vol 51 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Sun-Min Park ◽  
Hae-Ran Cho ◽  
Byung-Hyun Choi ◽  
Yong-Tae An ◽  
Ja-Bin Koo ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Cell Performance ◽  
Oxide Fuel ◽  
Functional Layer
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