A 2-D model for Intermediate Temperature Solid Oxide Fuel Cells Preliminarily Validated on Local Values

Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) technology offers interesting opportunities in the panorama of a larger penetration of renewable and distributed power generation, namely high electrical efficiency at manageable scales for both remote and industrial applications. In order to optimize the performance and the operating conditions of such a pre-commercial technology, an effective synergy between experimentation and simulation is fundamental. For this purpose, starting from the SIMFC (SIMulation of Fuel Cells) code set-up and successfully validated for Molten Carbonate Fuel Cells, a new version of the code has been developed for IT-SOFCs. The new release of the code allows the calculation of the maps of the main electrical, chemical, and physical parameters on the cell plane of planar IT-SOFCs fed in co-flow. A semi-empirical kinetic formulation has been set-up, identifying the related parameters thanks to a devoted series of experiments, and integrated in SIMFC. Thanks to a multi-sampling innovative experimental apparatus the simultaneous measurement of temperature and gas composition on the cell plane was possible, so that a preliminary validation of the model on local values was carried out. A good agreement between experimental and simulated data was achieved in terms of cell voltages and local temperatures, but also, for the first time, in terms of local concentration on the cell plane, encouraging further developments. This numerical tool is proposed for a better interpretation of the phenomena occurring in IT-SOFCs and a consequential optimization of their performance.

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CFD-Based Design of Microtubular Solid Oxide Fuel Cells

Journal of Heat Transfer ◽

10.1115/1.4000709 ◽

2010 ◽

Vol 132 (6) ◽

Cited By ~ 6

Author(s):

Stefano Cordiner ◽

Alessandro Mariani ◽

Vincenzo Mulone

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Power Density ◽

Fluid Dynamic ◽

Scale Up ◽

Design Procedure ◽

Operating Conditions ◽

Solid Oxide ◽

Local Concentration ◽

Oxide Fuel

Microtubular solid oxide fuel cells (MT-SOFCs) are interesting for portable and auxiliary power units energy production systems, due to their extremely fast startup time. However, a single cell provides power in the range of 1 W, thus the number of microtubes to reach a kW scale is relevant and packaging design issues arise also. In this paper a specifically developed design procedure is presented to face with system issues and bringing into account fluid-dynamic and thermal influence on system performance. The procedure also simplifies the stack manifold design by means of a modular scale-up procedure starting from a basic optimized configuration. To this aim, a computational fluid dynamics (CFD) model has been integrated with specific models for fuel cell simulation and then validated with tailored experimental data by varying operating conditions in terms of fuel utilization and electric load. A comprehensive three–dimensional (3D) thermal-fluid-dynamic model has then been applied to the analysis of both micro-assembly (i.e., 15 tube assembly) and midi-assembly (up to 45 tubes), showing an important role of local phenomena as current homogeneity and reactant local concentration that have a strong influence on power density and temperature distribution. Microreactor power density in the range of 0.3 kW/l have been demonstrated and a specific manifold design has been realized paving the way toward a modular realization of a 1 kW MT-SOFC.

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Thermofluid-Dynamic Analysis of Circular-Planar Type Intermediate-Temperature Solid Oxide Fuel Cells

Journal of Fuel Cell Science and Technology ◽

10.1115/1.2971050 ◽

2008 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Stefano Campanari ◽

Paolo Iora ◽

Andrea Lucchini ◽

Matteo Romano

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Dynamic Analysis ◽

Preferential Flow ◽

Operating Conditions ◽

Solid Oxide ◽

Intermediate Temperature ◽

Pure Hydrogen ◽

Oxide Fuel ◽

Type Intermediate

This work presents a computational thermofluid-dynamic analysis of circular-planar type intermediate-temperature solid oxide fuel cells (SOFCs), based on the Hexis design. A single cell, representative of the average conditions of a real stack, is simulated in detail considering the real anode and cathode channel design, featuring an array of square pegs supporting the interconnection layers. The analysis is developed starting from cell operating data assumed from real test experimental information for an anode-supported SOFC with a 100cm2 active area, fed with pure hydrogen, and is extended to different reactant flow rates and generated heat flux power densities to evidence a generalized correlation for the thermofluid-dynamic behavior of the fuel cell under variable operating conditions. Aiming to provide a set of general results for the calculation of the heat transfer coefficient, which is applicable for the purpose of a complete thermal and electrochemical finite volume analysis, the simulation calculates local temperature distributions depending on radial and angular positions. The fluid-dynamic analysis evidences the existence of preferential flow paths and nonuniformity issues of the gas flow field, which may affect significantly the cell performances, and indicates possible cell design improvements.

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