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Dresden, Germany

Lawlor V.,Upper Austria University of Applied Sciences | Lawlor V.,Dublin City University | Klein K.,EZelleron GmbH | Hochenauer C.,Upper Austria University of Applied Sciences | And 5 more authors.
Journal of Fuel Cell Science and Technology | Year: 2013

Standard anode supported micro tubular-solid oxide fuel cell (MT-SOFC) stacks may provide the oxidant, in relation to the fuel, in three different manifold regimes. Firstly, "co-flow" involves oxidant outside the MT-SOFC flowing co-linearly in relation to the fuel inside. Secondly, "counter flow" involves oxidant outside the MT-SOFC flowing counter-linearly in relation to the fuel inside the MT-SOFC. Finally, "cross-flow" involves the oxidant outside the MT-SOFC flowing perpendicular to the fuel flow inside the MT-SOFC. In order to examine the effect of manifold technique on MT-SOFC performance, a combination of numerical simulation and experimental measurements was performed. Furthermore, the cathode current tap location, in relation to the fuel flow, was also studied. It was found that the oxidant manifold and the location of the cathode current collection point on the MT-SOFC tested and modeled had negligible effect on the MT-SOFC's electrical and thermal performance. In this study, a single MT-SOFC was studied in order to establish the measurement technique and numerical simulation implementation as a prerequisite before further test involving a 7 cell MT-SOFC stack. Copyright © 2013 by ASME. Source


Lawlor V.,Upper Austria University of Applied Sciences | Lawlor V.,Dublin City University | Hochenauer C.,Upper Austria University of Applied Sciences | Griesser S.,Upper Austria University of Applied Sciences | And 9 more authors.
Journal of Fuel Cell Science and Technology | Year: 2011

Micro-tubular solid oxide fuel cells (MT-SOFCs) are a much smaller version of larger tubular SOFCs. They are operational within seconds and allow a higher power density per volume than the larger version. Hence they are a potential technology for automotive, auxiliary and small scale power supply devices. In this study a commercially available computational fluid dynamic (CFD) software program was used to predict a MT-SOFCs performance when located inside a high temperature wind tunnel experimental apparatus. In Part I, experimentally measured temperature profiles were recorded via thermo-graphic analyses and I/V curves. These measurements were used in this study to establish the predictability and validity of the CFD code and furthermore understand the MT-SOFC attributes measured in Part I. A maximum 4 I/V curve deviation and 6 K temperature deviation between the experimentally measured and model predicted results was observed. Thus, the model predicted the MT-SOFCs performance in the experimental environment very accurately. A very critical observation was the current density and temperature profile across the MT-SOFC that was strongly dependent on the distance from the hydrogen/fuel inlet. Not only was the model validated but also a grid and quantitative solution analysis is explicitly shown and discussed. This resulted in the optimum grid density and the indication that a normally undesirable high grid aspect ratio is acceptable for similar MT-SOFC modeling. These initial simulations and grid/solution analysis are the prerequisite before performing a further study including multiple MT-SOFCs within a stack using different fuels is also envisaged. © 2011 American Society of Mechanical Engineers. Source


Lawlor V.,Upper Austria University of Applied Sciences | Lawlor V.,Dublin City University | Zauner G.,Upper Austria University of Applied Sciences | Hochenauer C.,Upper Austria University of Applied Sciences | And 11 more authors.
Journal of Fuel Cell Science and Technology | Year: 2010

The purpose of the first part of this study was to compare four different temperature measuring methods. The application of these tools for possible temperature monitoring or calibration of monitors of microtubular solid oxide fuel cells (MT-SOFCs) is explored. It was found that a thermographic camera is very useful to visualize the temperature gradient on the outside of a cell, while an electrochemical impedance spectroscopy method was useful for estimating the core temperature of a test cell. A standard thermocouple was also used in combination with the previous two methods. Furthermore, an inexpensive laser guided thermometer was also tested for MT-SOFC temperature measurement. This initial study has opened up a range of questions not only about the effect of the experimental apparatus on the measurement results but also about the radial temperature distribution through a MT-SOFC in a working mode. Both these topics will be further investigated in part II of this study through a computational fluid dynamics study. This should provide additional interesting information about any differences between testing single cells and those within a bundle of cells. The discussed results are expected to be mainly temperature related, which should have direct consequences on power output and optimized gas inlet temperatures. © 2010 American Society of Mechanical Engineers. Source


Trademark
EZelleron GmbH | Date: 2009-01-12

Electrical energy; combustibles oils and fuels; gaseous mixture of combustible oils and fuels. Machines for processing metals, woods and plastics; machines for the chemical industry, for agriculture and for mining, namely, agricultural seed planting machines, drills for the mining industry; motors and engines and structural and/or replacement parts thereof, except for land vehicles; emergency electrical power supply units and ancillary electrical units, namely, auxiliary power units for supplying electrical power, integrated into motor vehicles, bicycles, ships, aircraft and structural and/or replacement parts thereof; couplings for machines and structural and/or replacement parts thereof for power transmission, except for land vehicles; non-manually operated agricultural implements, namely, reapers, sowers; fuel converters for combustion engines; steam condensers in the nature of machine parts; turbines, except for land vehicles; electric power generators for emergency use. Fuel cells for bicycles, power generators, ships, aircraft and structural and/or replacement parts thereof; electrical batteries, namely, electrical, nickel-cadmium, lithium-ion, nickel-metal hydrid, and pb-accumulator storage batteries, charging devices for electrical storage batteries and fuel cells and systems made therefrom; fuel cell stacks; storage batteries; electrical solar cells and systems assembled therefrom; charging devices or mobile electrical power supply devices for providing electrical energy from chemical energy; electrical condensers; cartridges for fuel cells; apparatus and implements for conducting, switching, converting, storing, regulating and controlling electricity; chargers for electrical energy storage devices.


Paciejewska K.,EZelleron GmbH | Kuhn S.,EZelleron GmbH | Mnich S.,EZelleron GmbH
Ceramic Engineering and Science Proceedings | Year: 2014

The objective of the experimental investigations presented here was the development of a dense chemical reaction blocking layer (CRBL) from commercially available gadolinium-doped ceria (GDC) powders deposited by dip coating onto microtubular solid oxide fuel cells (SOFC). The preparation of suspensions as well as the process of sintering was adjusted. The results indicate that the layer properties are essentially determined by the width of the particle size distribution (PSD) - apart from the colloidal stability. Two methods were applied for achieving narrow size distribution additional to dispersion: grinding and centrifugation for achieving a narrow PSD width. As a result, the particles could be sintered together even at l300°C and a layer with a density close to 99% could be reached. In contrast, simple ultrasonic dispersion of powders diminished the distribution width insufficiently and gave porous layer even at l600°C. Furthermore, experiments at the sintering process showed that particles with the narrowest original PSD can be sintered at lower temperature than others with a broader PSD. Copyright © 2015 by The American Ceramic Society. Source

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