Entropy Generation Minimization in a Tubular Solid Oxide Fuel Cell

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Entropy Generation ◽  
Energy Equation ◽  
Solid Oxide ◽  
Geometrical Parameters ◽  
Oxide Fuel ◽  
Cell Geometry ◽  
Cell Efficiency ◽  
Entropy Generation Minimization

The aim of the paper is to investigate possible design modifications in tubular solid oxide fuel cell geometry to increase its performance. The analysis of the cell performances is conducted on the basis of the entropy generation. The use of this technique makes it possible to identify the phenomena provoking the main irreversibilities, understand their causes and propose changes in the system design and operation. The different contributions to the entropy generation are analyzed in order to develop new geometries that increase the fuel cell efficiency. To achieve this purpose, a CFD model of the cell is used. The model includes energy equation, fluid dynamics in the channels and in porous media, current transfer, chemical reactions, and electrochemistry. The geometrical parameters of the fuel cell are modified to minimize the overall entropy generation.

Entropy Generation Minimization in a Tubular Solid Oxide Fuel Cell

2008 ◽  
Author(s):  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Entropy Generation ◽  
Energy Equation ◽  
Solid Oxide ◽  
Geometrical Parameters ◽  
Oxide Fuel ◽  
Cfd Model ◽  
Cell Efficiency ◽  
Entropy Generation Minimization

The aim of the paper is to investigate possible design modifications in tubular solid oxide fuel cell (SOFC) geometry to increase its performance. The analysis of the cell performances is conducted on the basis of the entropy generation. The use of this technique makes it possible to identify the phenomena provoking the main irreversibilities, understand their causes and propose changes in the system design and operation. The different contributions to the entropy generation are analyzed in order to develop new geometries that increase the fuel cell efficiency. To achieve this purpose, a CFD model of the cell is used. The model includes energy equation, fluid dynamics in the channels and in porous media, current transfer, chemical reactions and electrochemistry. The geometrical parameters of the fuel cell are modified to minimize the overall entropy generation.

Entropy Generation in a Solid Oxide Fuel Cell

2008 ◽  
Author(s):  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Entropy Generation ◽  
Energy Equation ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cfd Model ◽  
Component Level ◽  
Cell Efficiency ◽  
Second Law Analysis

The aim of the paper is to investigate possible improvements in the design of solid oxide fuel cells (SOFC). The first improvement is conducted on the system, by performing a second law analysis at component level. The analysis is then performed on the fuel cell. To achieve this purpose, a CFD model of the cell is used. The model includes energy equation, fluid dynamics in the channels and in porous media, current transfer, chemical reactions and electrochemistry. The analysis of the cell performances is conducted on the basis of the entropy generation. The use of this technique makes it possible to identify the phenomena provoking the main irreversibilities, understand their causes and propose changes in the system design and operation. The different contributions to the entropy generation are analyzed in order to develop new geometries that increase the fuel cell efficiency.

Entropy generation analysis for the design optimization of solid oxide fuel cells

2011 ◽  
Vol 21 (5) ◽  
pp. 535-558 ◽  
Author(s):  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Fuel Cell ◽  
Power Density ◽  
Entropy Generation ◽  
Solid Oxide ◽  
Optimization Process ◽  
Methane Steam Reforming ◽  
Geometrical Parameters ◽  
Oxide Fuel ◽  
Content Type ◽  
Independent Variables

PurposeThe aim of this paper is to investigate performance improvements of a monolithic solid oxide fuel cell geometry through an entropy generation analysis.Design/methodology/approachThe analysis of entropy generation rates makes it possible to identify the phenomena that cause the main irreversibilities in the fuel cell, to understand their causes and to propose changes in the design and operation of the system. The various contributions to entropy generation are analyzed separately in order to identify which geometrical parameters should be considered as the independent variables in the optimization procedure. The local entropy generation rates are obtained through 3D numerical calculations, which account for the heat, mass, momentum, species and current transport. The system is then optimized in order to minimize the overall entropy generation and increase efficiency.FindingsIn the optimized geometry, the power density is increased by about 10 per cent compared to typical designs. In addition, a 20 per cent reduction in the fuel cell volume can be achieved with less than a 1 per cent reduction in the power density with respect to the optimal design.Research limitations/implicationsThe physical model is based on a simple composition of the reactants, which also implies that no chemical reactions (water gas shift, methane steam reforming, etc.) take place in the fuel cell. Nevertheless, the entire procedure could be applied in the case of different gas compositions.Practical implicationsEntropy generation analysis allows one to identify the geometrical parameters that are expected to play important roles in the optimization process and thus to reduce the free independent variables that have to be considered. This information may also be used for design improvement purposes.Originality/valueIn this paper, entropy generation analysis is used for a multi‐physics problem that involves various irreversible terms, with the double use of this physical quantity: as a guide to select the most relevant design geometrical quantities to be modified and as objective function to be minimized in the optimization process.

A Study of Transport Geometry on Heat/Mass Transfer and Polarization of a Solid Oxide Fuel Cell

2006 ◽  
Author(s):  
Yan Ji ◽  
J. N. Chung ◽  
Kun Yuan
Keyword(s):  
Mass Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Heat Mass Transfer ◽  
Three Dimensional ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Transfer Coefficients ◽  
Cell Efficiency ◽  
Current Path

The main objective of this paper is to examine the effects of transport geometry on the efficiency of an electrolyte-supported solid oxide fuel cell. A three-dimensional thermo-fluid-electrochemical model is developed to the influences of channel dimensions, rib width and electrolyte thickness on the temperature, mass transfer coefficients, species concentration, local current density and power density. Results demonstrate that decreasing the height of flow channels can significantly lower the average solid temperature and improve the cell efficiency due to higher heat/mass transfer coefficient between the channel wall and flow stream, and a shorter current path. However, this improvement is limited for the smallest channel. The cell with a thicker rib width and a thinner electrolyte layer has higher efficiency and lower average temperature. Numerical simulation will be expected to help optimize the design of a solid oxide fuel cell.

scholarly journals A 3-dimensional mathematical model to study effects of geometrical parameters on performance of solid oxide fuel cell

2021 ◽  
Author(s):  
Vikalp Jha ◽  
Vikranth Kumar Surasani ◽  
Balaji Krishnamurthy
Keyword(s):  
Mathematical Model ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Cell Performance ◽  
Channel Width ◽  
Geometrical Parameters ◽  
Oxide Fuel ◽  
Fuel Cell Performance ◽  
Simulation Results

A 3D mathematical model is developed to study effects of various geometrical parameters such as cathode to anode thickness ratio, rib width, and channel width under various flow conditions, on the performance of solid oxide fuel cell (SOFC). These parameters represent the cathode supported configuration of the solid oxide fuel cell. It is observed from simulation results that performance of SOFC fuel cell is increased at higher cathode to anode thickness. Simulation results also showed that for different volumetric flow rates, the current density and fuel cell performance decrease as rib width increases, what is due to higher contact resistance. It is also shown that by increasing the channel width, the fuel cell performance was increased due to increase in the reaction surface area. Simulation results are compared and validated with literature experimental data, showing well agreement.

Entropy generation analysis in a monolithic-type solid oxide fuel cell (SOFC)

Energy ◽  
2009 ◽  
Vol 34 (7) ◽  
pp. 850-865 ◽  
Author(s):  
Adriano Sciacovelli ◽  
Vittorio Verda
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Entropy Generation ◽  
Solid Oxide ◽  
Oxide Fuel

scholarly journals Entropy generation analysis of a Solid Oxide Fuel Cell by Computational Fluid Dynamics: Influence of electrochemical model and its parameters

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 577-589 ◽  
Author(s):  
José Ramírez-Minguela ◽  
Juan Mendoza-Miranda ◽  
José Rodríguez-Muñoz ◽  
Vicente Pérez-García ◽  
Jorge Alfaro-Ayala ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Entropy Generation ◽  
Current Density ◽  
Solid Oxide ◽  
Entropy Generation Rate ◽  
Ohmic Loss ◽  
Oxide Fuel ◽  
Thermodynamic Irreversibility ◽  
Electrochemical Model

The aim of this paper is to evaluate numerically the effect of varying the electrochemical model and its parameters on the performance and entropy generation of a mono-block-layer build (MOLB) type geometry of a solid oxide fuel cell. Particularly, the influence of the exchange of current density, the electrical conductivity of the electrodes and the electrolyte has been studied and the prediction of the thermodynamic irreversibility by means of an entropy generation analysis is considered. The numerical analysis consider a 3-D CFD model that takes into account the mass transfer, heat transfer, species transport, and electrochemical reactions. Several numerical simulations were performed and each contribution to the local entropy generation rate was computed. The results show different trends of the current density, temperature, species, activation loss, ohmic loss, and concentration loss along the fuel cell. Also, the results show strong variations of the local and global entropy generation rates between the cases analyzed. It is possible to conclude that the fuel cell performance and the prediction of thermodynamic irreversibility can be significantly affected by the choice of the electrochemical models and its parameters, which must be carefully selected.

Three-Dimensional Simulation of Planar Solid Oxide Fuel Cell Stack

2008 ◽  
Vol 128 (2) ◽  
pp. 459-466 ◽  
Author(s):  
Yoshitaka Inui ◽  
Tadashi Tanaka ◽  
Tomoyoshi Kanno
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Three Dimensional ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Stack ◽  
Dimensional Simulation
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