scholarly journals Modeling the dynamic operation of a small fin plate heat exchanger – parametric analysis

2015 ◽  
Vol 36 (3) ◽  
pp. 85-103 ◽  
Author(s):  
Konrad Motyliński ◽  
Jakub Kupecki
Keyword(s):  
Fuel Cells ◽  
Heat Exchanger ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Critical Role ◽  
Plate Heat Exchanger ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Promising Alternative ◽  
Plate Heat

Abstract Given its high efficiency, low emissions and multiple fuelling options, the solid oxide fuel cells (SOFC) offer a promising alternative for stationary power generators, especially while engaged in micro-combined heat and power (μ-CHP) units. Despite the fact that the fuel cells are a key component in such power systems, other auxiliaries of the system can play a critical role and therefore require a significant attention. Since SOFC uses a ceramic material as an electrolyte, the high operating temperature (typically of the order of 700–900 °C) is required to achieve sufficient performance. For that reason both the fuel and the oxidant have to be preheated before entering the SOFC stack. Hot gases exiting the fuel cell stack transport substantial amount of energy which has to be partly recovered for preheating streams entering the stack and for heating purposes. Effective thermal integration of the μ-CHP can be achieved only when proper technical measures are used. The ability of efficiently preheating the streams of oxidant and fuel relies on heat exchangers which are present in all possible configurations of power system with solid oxide fuel cells. In this work a compact, fin plate heat exchanger operating in the high temperature regime was under consideration. Dynamic model was proposed for investigation of its performance under the transitional states of the fuel cell system. Heat exchanger was simulated using commercial modeling software. The model includes key geometrical and functional parameters. The working conditions of the power unit with SOFC vary due to the several factors, such as load changes, heating and cooling procedures of the stack and others. These issues affect parameters of the incoming streams to the heat exchanger. The mathematical model of the heat exchanger is based on a set of equations which are simultaneously solved in the iterative process. It enables to define conditions in the outlets of both the hot and the cold sides. Additionally, model can be used for simulating the stand-alone heat exchanger or for investigations of a semiadiabatic unit located in the hotbox of the μ-CHP unit.

scholarly journals Integrated Cr and S poisoning of a La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathode for solid oxide fuel cells

RSC Advances ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 7-14
Author(s):  
Cheng Cheng Wang ◽  
Mortaza Gholizadeh ◽  
Bingxue Hou ◽  
Xincan Fan
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Cell Performance ◽  
Oxide Fuel ◽  
Performance Deterioration

Strontium segregation in a La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) electrode reacts with Cr and S in a solid oxide fuel cell (SOFC), which can cause cell performance deterioration.

scholarly journals A robust and active hybrid catalyst for facile oxygen reduction in solid oxide fuel cells

2017 ◽  
Vol 10 (4) ◽  
pp. 964-971 ◽  
Author(s):  
Yu Chen ◽  
Yan Chen ◽  
Dong Ding ◽  
Yong Ding ◽  
YongMan Choi ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide Fuel Cell ◽  
Oxygen Reduction ◽  
Electrocatalytic Activity ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Hybrid Catalyst ◽  
Fuel Cell Cathode

A hybrid catalyst coating dramatically enhances the electrocatalytic activity and durability of a solid oxide fuel cell cathode.

Direct Oxidation of Waste Vegetable Oil in Solid Oxide Fuel Cells

2005 ◽  
Author(s):  
Z. F. Zhou ◽  
R. Kumar ◽  
S. T. Thakur ◽  
L. R. Rudnick ◽  
H. Schobert ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Vegetable Oil ◽  
Solid Oxide ◽  
Jet Fuels ◽  
Oxide Fuel ◽  
Direct Oxidation ◽  
Waste Vegetable Oil ◽  
Pre Treatment

Solid oxide fuel cells with ceria, ceria-Cu, and ceria-Rh anode were demonstrated to generate stable electric power with waste vegetable oil through direct oxidation of the fuel. The only pre-treatment to the fuel was a filtration to remove particulates. The performance of the fuel cell was stable over 100 hours for the waste vegetable oil without dilution. The generated power was up to 0.25 W/cm2 for ceria-Rh fuel cell. This compares favorably with previously studied hydrocarbon fuels including jet fuels and Pennsylvania crude oil.

scholarly journals Solid oxide fuel cells power unit reformer/burner/heat-exchanger module experimental study

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 631-640
Author(s):  
Vladimir Munts ◽  
Yulia Volkova ◽  
Mikhail Ershov ◽  
Vladimir Tuponogov ◽  
Nikita Plotnikov
Keyword(s):  
Fuel Cells ◽  
Heat Exchanger ◽  
Solid Oxide Fuel Cells ◽  
Power Unit ◽  
Partial Oxidation ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Experimental Procedure ◽  
Air Supply ◽  
Partial Oxidation Reforming

The article contains the installation description, experimental procedure, and results for the catalytic partial oxidation reformer/catalyst burner/heat-exchanger module. Mathematical modeling for all major blocks temperatures dependence on the reformer air supply ratio was carried out. In the air supply ratio range under study the model was verified using experimental data. The model was further practically used for the solid oxide fuel cells power unit automatic control modes development. The partial oxidation reforming solid oxide fuel cells power unit characteristics were evaluated.

scholarly journals Evaluation of Bi2V0.9Cu0.1O5.35—an Aurivillius-Type Conducting Oxide—as a Cathode Material for Single-Chamber Solid-Oxide Fuel Cells

2010 ◽  
Vol 7 (2) ◽  
Author(s):  
Zongping Shao ◽  
Jennifer Mederos ◽  
Chan Kwak ◽  
Sossina M. Haile
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
Sharp Decrease ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Single Chamber ◽  
Ion Conductor ◽  
Fuel Cell Performance

The compound Bi2V0.9Cu0.1O5.35, a typical Aurivillius-type fast oxygen ion conductor, was evaluated as a possible cathode material for single-chamber solid-oxide fuel cells operated under mixed propane and oxygen. The material was found to be structurally stable under various C3H8+O2 environments over a wide temperature range and furthermore displayed low catalytic activity for propane oxidation. However, at temperatures above 650°C, detrimental reactions between the cathode and the ceria electrolyte occurred, producing low conductivity interfacial phases. At these high temperatures the cathode additionally underwent extensive sintering and loss of porosity and, thus, stable fuel cell operation was limited to furnace temperatures of <600°C. Even under such conditions, however, the partial oxidation occurring at the anode (a ceria nickel cermet) resulted in cell temperatures as much as 70–110°C higher than the gas-phase temperature. This explains the sharp decrease in fuel cell performance with time during operation at a furnace temperature of 586°C. Under optimized conditions, a peak power density of ∼60 mW/cm2 was obtained, which does not compete with recent values obtained from higher activity cathodes. Thus, the poor electrochemical activity of Bi2V0.9Cu0.1O5.35, combined with its chemical instability at higher temperatures, discourages further consideration of this material as a cathode in single-chamber fuel cells.

Direct-Write Microfabrication of Single-Chamber Solid Oxide Fuel Cells with Interdigitated Electrodes

2006 ◽  
Vol 972 ◽  
Author(s):  
Melanie Kuhn ◽  
Teko Napporn ◽  
Michel Meunier ◽  
Daniel Therriault ◽  
Srikar Vengallatore
Keyword(s):  
Particle Size ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Size Distribution ◽  
Solid Oxide ◽  
Extrusion Pressure ◽  
Direct Write ◽  
Oxide Fuel ◽  
Single Chamber

AbstractMiniaturized single-chamber solid-oxide fuel cells (SC-SOFC) are a promising class of devices for portable power generation required in the operation of distributed networks of microelectromechanical systems (MEMS) in harsh environments. The single-face configuration, which consists of interdigitated (comb-like) array of electrodes on an yttria-stabilized zirconia (YSZ) electrolyte substrate, is of particular interest because of the ease of high-temperature microfluidic packaging and integration with MEMS. The primary design consideration for this configuration is the minimization of electrode widths and inter-electrode spacings to dimensions on the order of a few micrometers. This is necessary to minimize polarization resistance and increase fuel cell efficiency. Achieving these geometries using standard microfabrication methods is difficult because of the thickness, porosity, and complex chemistries of the electrodes. Here, we report the development of an innovative and rapid method for manufacturing SC-SOFCs with interdigitated electrodes using robot-controlled direct-writing. The main steps consist of: (i) formation of inks (or suspensions) using anode (NiO-YSZ) and cathode (lanthanum strontium manganite) powders, (ii) pressure-driven extrusion of inks through a micronozzle using a robot-controlled platform, and (iii) sequential sintering to form the fuel cell. The first-generation SC-SOFC device, with electrode widths of 130 μm and inter-electrode spacing of 300 μm, has been manufactured using direct-write microfabrication. The electrodes have been extensively characterized using electron microscopy and x-ray diffraction to assess porosity and to confirm phase identity. The primary process parameters in this approach are the particle size and size distribution, rheological properties of the suspension, extrusion pressure, nozzle size, stage velocity, and sintering conditions. As the first step in the development of detailed process-structure-performance correlations for the fuel cells, we have studied the effects of extrusion pressure (in the range 30-40 bar) and stage velocity (in the range 0.2-2.0 mm/s) on the geometry and size of electrodes, for fixed suspension viscosity and nozzle diameter. An optimal combination of speed and pressure has been identified and catalogued in the form of process maps. Similarly, the particle size distribution of the anode and cathode powders is found to have a significant effect on the microstructure, especially porosity, of the sintered electrodes. The implications of these results for the design of the next generation of SC-SOFC, with reduced electrode dimensions and improved electrochemical performance, will be discussed.

Cogeneration of ethylene and electricity in symmetrical protonic solid oxide fuel cells based on a La0.6Sr0.4Fe0.8Nb0.1Cu0.1O3−δ electrode

2020 ◽  
Vol 8 (48) ◽  
pp. 25978-25985
Author(s):  
Jun Li ◽  
Jie Hou ◽  
Xiuan Xi ◽  
Ying Lu ◽  
Mingming Li ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cell Reactor

Symmetrical solid oxide fuel cell reactor with BaZr0.1Ce0.7Y0.1Yb0.1O3−δ as electrolyte and La0.6Sr0.4Fe0.8Nb0.1Cu0.1O3−δ as electrodes is applied to cogenerate ethylene and electricity.

scholarly journals Structure and properties of MgMxCr2−xO4 (M = Li, Mg, Ti, Fe, Cu, Ga) spinels for electrode supports in solid oxide fuel cells

2014 ◽  
Vol 2 (42) ◽  
pp. 18106-18114 ◽  
Author(s):  
Elena Stefan ◽  
Paul A. Connor ◽  
Abul K. Azad ◽  
John T. S. Irvine
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Structure And Properties ◽  
Scaffold Materials

The paper investigates the structure and properties of novel electrode scaffold materials for solid oxide fuel cell (SOFC), such as MgMxCr2−xO4, (M = Li, Mg, Ti, Fe, Cu, Ga).

Modification of Results From Computational-Fluid-Dynamics Simulations of Single-Cell Solid-Oxide Fuel Cells to Estimate Multicell Stack Performance

2010 ◽  
Vol 8 (2) ◽  
Author(s):  
William J. Sembler ◽  
Sunil Kumar
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Single Cell ◽  
Three Dimensional ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cfd Model ◽  
Fuel Cell Performance ◽  
Cfd Models

A typical single-cell fuel cell is capable of producing less than 1 V of direct current. Therefore, to produce the voltages required in most industrial applications, many individual fuel cells must typically be stacked together and connected electrically in series. Computational fluid dynamics (CFD) can be helpful to predict fuel-cell performance before a cell is actually built and tested. However, to perform a CFD simulation using a three-dimensional model of an entire fuel-cell stack can require a considerable amount of time and multiprocessor computing capability that may not be available to the designer. To eliminate the need to model an entire multicell assembly, a study was conducted to determine the incremental effect on fuel-cell performance of adding individual solid-oxide fuel cells (SOFCs) to a CFD model of a multicell stack. As part of this process, a series of simulations was conducted to establish a CFD-nodal density that would not only produce reasonably accurate results but could also be used to create and analyze the relatively large models of the multicell stacks. Full three-dimensional CFD models were then created of a single-cell SOFC and of SOFC stacks containing two, three, four, five, and six cells. Values of the voltages produced when operating with various current densities, together with temperature distributions, were generated for each of these CFD models. By comparing the results from each of the simulations, adjustment factors were developed to permit single-cell CFD results to be modified to estimate the performance of stacks containing multiple fuel cells. The use of these factors could enable fuel-cell designers to predict multicell stack performance using a CFD model of only a single cell.

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