Significance of radiative heat transfer in modeling a tubular micro-solid oxide fuel cell

2020 ◽  
Vol 156 ◽  
pp. 106499
Author(s):  
Saeid Amiri ◽  
R.E. Hayes ◽  
Partha Sarkar
Keyword(s):  
Heat Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Solid Oxide ◽  
Oxide Fuel

Spectral Radiative Heat Transfer Analysis of the Planar SOFC

2004 ◽  
Author(s):  
David L. Damm ◽  
Andrei G. Fedorov
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Solid Oxide ◽  
Radiative Properties ◽  
Radiative Heat Flux ◽  
Oxide Fuel

Thermo-mechanical failure of components in planar-type solid oxide fuel cells (SOFCs) depends strongly on the local temperature gradients at the interfaces of different materials. Therefore, it is of paramount importance to accurately predict the temperature fields within the stack, especially near the interfaces. Because of elevated operating temperatures (of the order of 1000 K or even higher), radiation heat transfer could become a dominant mode of heat transfer in the SOFCs. In this study, we extend our recent work on radiative effects in solid oxide fuel cells (Journal of Power Sources, Vol. 124, No. 2, pp. 453–458) by accounting for the spectral dependence of the radiative properties of the electrolyte material. The measurements of spectral radiative properties of the polycrystalline yttria-stabilized zirconia (YSZ) electrolyte we performed indicate that an optically thin approximation can be used for treatment of radiative heat transfer. To this end, the Schuster-Schwartzchild two-flux approximation is used to solve the radiative transfer equation (RTE) for the spectral radiative heat flux, which is then integrated over the entire spectrum using an N-band approximation to obtain the total heat flux due to thermal radiation. The divergence of the total radiative heat flux is then incorporated as a heat sink into a 3-D thermo-fluid model of a SOFC through the user-defined function utility in the commercial FLUENT CFD software. The results of sample calculations are reported and compared against the baseline cases when no radiation effects are included and when the spectrally gray approximation is used for treatment of radiative heat transfer.

Spectral Radiative Heat Transfer Analysis of the Planar SOFC

2005 ◽  
Vol 2 (4) ◽  
pp. 258-262 ◽  
Author(s):  
David L. Damm ◽  
Andrei G. Fedorov
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Solid Oxide ◽  
Radiative Properties ◽  
Radiative Heat Flux ◽  
Oxide Fuel

Thermo-mechanical failure of components in planar-type solid oxide fuel cells (SOFCs) depends strongly on the local temperature gradients at the interfaces of different materials. Therefore, it is of paramount importance to accurately predict the temperature fields within the stack, especially near the interfaces. Because of elevated operating temperatures (of the order of 1000K or even higher), radiation heat transfer could become a dominant mode of heat transfer in the SOFCs. In this study, we extend our recent work on radiative effects in solid oxide fuel cells [J. Power Sources, 124, No. 2, pp. 453–458] by accounting for the spectral dependence of the radiative properties of the electrolyte material. The measurements of spectral radiative properties of the polycrystalline yttria-stabilized zirconia electrolyte we performed indicate that an optically thin approximation can be used for treatment of radiative heat transfer. To this end, the Schuster–Schwartzchild two-flux approximation is used to solve the radiative transfer equation for the spectral radiative heat flux, which is then integrated over the entire spectrum using an N-band approximation to obtain the total heat flux due to thermal radiation. The divergence of the total radiative heat flux is then incorporated as a heat sink into a three-dimensional thermo-fluid model of a SOFC through the user-defined function utility in the commercial FLUENT computational fluid dynamics software. The results of sample calculations are reported and compared against the base line cases when no radiation effects are included and when the spectrally gray approximation is used for treatment of radiative heat transfer.

The Role of Radiative Heat Transfer With Participating Gases on the Temperature Distribution in Solid Oxide Fuel Cells

2004 ◽  
Author(s):  
J. D. J. VanderSteen ◽  
J. G. Pharoah
Keyword(s):  
Heat Transfer ◽  
Fuel Cells ◽  
Temperature Distribution ◽  
Solid Oxide Fuel Cells ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Transport Processes ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Participating Media

Solid oxide fuel cell (SOFC) technology has been shown to be viable, but its profitability has not yet been seen. To achieve a high net efficiency at a low net cost, a detailed understanding of the transport processes both inside and outside of the SOFC stack is required. Of particular significance is an accurate determination of the temperature distribution because material properties, chemical kinetics and transport properties depend heavily on the temperature. Effective utilization of the heat can lead to a substantial increase in overall system efficiency and decrease in operating cost. Despite the extreme importance in accurately predicting temperature, the majority of SOFC modeling work ignores radiative heat transfer. SOFCs operate at temperatures around or above 1200 K, where radiation effects can be significant. In order to correctly predict the radiation heat transfer, participating gases must also be included. Water vapour and carbon dioxide can absorb, emit, and scatter radiation, and are present at the anode in high concentrations. This paper presents a thermal transport model for analyzing heat transfer and improving thermal management within planar SOFCs. The model was implemented using a commercial computational fluid dynamic (CFD) code and includes conduction, convection, and radiation in a participating media. It is clear from this study that radiation must be considered when modelling solid oxide fuel cells. The effect of participating media radiation was shown to be minimal in this geometry, but it is likely to be more important in tubular geometries.

Modeling on Transport Performance of Integrated-Planar Solid Oxide Fuel Cell

2010 ◽  
Author(s):  
Chao Zhang ◽  
Xiaoze Du ◽  
Lijun Yang ◽  
Yongping Yang ◽  
Yazhen Hao
Keyword(s):  
Heat Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Knudsen Diffusion ◽  
Solid Oxide ◽  
Chemical Components ◽  
Three Dimension ◽  
Oxide Fuel ◽  
Porous Support ◽  
Polarization Characteristics

The three dimension physico-mathematical model was established for the integrated planar solid oxide fuel cell (IP-SOFC) with the couples of multi components flow of reacting gas, heat transfer and electro-chemical process in order to reveal the inherent multi-scale effect of gas distributing duct and the porous support layer, and also, the microscale effect on the transport process in fuel cell. The mutual influences between heat transfer and chemical components transport were included in the model. In addition, the thermal effect of chemical reactions and its influences on polarizations of fuel cell were considered. And also, besides the Darcy diffusion, the Knudsen diffusion in the sub-microscale structure of the porous support is taken into consideration. Numerical simulation was employed to solve the model, by which, the output performance and polarization characteristics of a single cell were analyzed and compared for electrolyte-supported, anode-supported and cathode-supported SOFC, respectively. The present model was also validated comparing with the experimental data.

Cfd Analysis of Heat Transfer in a Microtubular Solid Oxide Fuel Cell Stack

2014 ◽  
Vol 35 (3) ◽  
pp. 293-304 ◽  
Author(s):  
Paulina Pianko-Oprych ◽  
Ekaterina Kasilova, ◽  
Zdzisław Jaworski
Keyword(s):  
Heat Transfer ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Heat Losses ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Reaction Heat ◽  
Flux Profile ◽  
The Impact

Abstract The aim of this work was to achieve a deeper understanding of the heat transfer in a microtubular Solid Oxide Fuel Cell (mSOFC) stack based on the results obtained by means of a Computational Fluid Dynamics tool. Stack performance predictions were based on simulations for a 16 anodesupported mSOFCs sub-stack, which was a component of the overall stack containing 64 fuel cells. The emphasis of the paper was put on steady-state modelling, which enabled identification of heat transfer between the fuel cells and air flow cooling the stack and estimation of the influence of stack heat losses. Analysis of processes for different heat losses and the impact of the mSOFC reaction heat flux profile on the temperature distribution in the mSOFC stack were carried out. Both radiative and convective heat transfer were taken into account in the analysis. Two different levels of the inlet air velocity and three different values of the heat losses were considered. Good agreement of the CFD model results with experimental data allowed to predict the operation trends, which will be a reliable tool for optimisation of the working setup and ensure sufficient cooling of the mSOFC stack.

Modelling heat transfer for a tubular micro-solid oxide fuel cell with experimental validation

2013 ◽  
Vol 233 ◽  
pp. 190-201 ◽  
Author(s):  
Saeid Amiri ◽  
R.E. Hayes ◽  
K. Nandakumar ◽  
Partha Sarkar
Keyword(s):  
Heat Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Experimental Validation ◽  
Solid Oxide ◽  
Oxide Fuel

Performance of an Integrated Microtubular Fuel Reformer and Solid Oxide Fuel Cell System

2010 ◽  
Vol 7 (3) ◽  
Author(s):  
John R. Izzo ◽  
Aldo A. Peracchio ◽  
Wilson K. S. Chiu
Keyword(s):  
Heat Transfer ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Packed Bed Reactor ◽  
Limiting Current ◽  
Design Parameters ◽  
Heat Of Reaction ◽  
Oxide Fuel ◽  
Flow Rates

A numerical model is developed to study the performance of an integrated tubular fuel reformer and solid oxide fuel cell (SOFC) system. The model is used to study how the physical dimensions of the reformer, gas composition and the species flow rates of a methane feed stream undergoing autothermal reforming (ATR) affect the performance of an SOFC. The temperature in the reformer changes significantly due to the heat of reaction, and the reaction rates are very sensitive to the temperature and species concentrations. Therefore, it is necessary to couple the heat and mass transfer to accurately model the species conversion of the reformate stream. The reactions in the SOFC contribute much less to the temperature distribution than in the reformer and therefore the heat transfer in the SOFC is not necessary to model. A packed bed reactor is used to describe the reformer, where the chemical mechanism and kinetics are taken from the literature for nickel catalyst on a gamma alumina support. Heat transfer in the reformer’s gas and solid catalyst phases are coupled while the gas phase in the SOFC is at a uniform temperature. The SOFC gas species are modeled using a plug flow reactor. The models are in good agreement with experimental data. It is observed that the reformer temperature decreases with an increase in the reformer inlet water-to-fuel ratio and there is a slight decrease in the voltage of the SOFC from higher water content but an increase in limiting current density from a higher hydrogen production. The numerical results show that the flow rates and reformer length are critical design parameters because if not properly designed they can lead to incomplete conversion of the methane fuel to hydrogen in the reformer, which has the greatest impact on the SOFC performance in the integrated ATR reformer and SOFC system.

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