Research Report 2012

Transcription

Zurich Universities of
Applied Sciences and Arts
r
www.engineering.zhaw.ch
d
Research & Development
Beispiel von Verschiebungen einer konischen Schale mit
Durchschlagsverhalten und gewölbten Lösungen. Die konische Schale deformiert sich und nähert sich nach einer gewissen Zeit einer instabilen Region, in der die Schale durchschlagen kann. Erhöht sich die Verschiebung weiter, kommen
wir zu einem Bifurkationspunkt, an dem gewölbte Deformationen auftreten.
Example of a conical shell displacements with snap-through
and warp solutions. The conical shell starts to deform inward
and after a while it approaches an unstable snap-through region, by further increasing the displacement, we arrive at a
bifurcation point where warp deformations show up.
Contents
Vorwort
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Preface
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1 Modeling and More
1.1 Simulation von Personenströmen als Kontinuum bei Grossanlässen und dichtem
Personenverkehr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Materialcharakterisierung in der Lebensmitteltechnologie mittels Ultraschall-Verfahren
1.3 Neuartig optimierte Kühlprozesse zur nachhaltigen Herstellung von gefüllten Schokoladenprodukten mit verbesserter Qualität . . . . . . . . . . . . . . . . . . . . . . . .
1.4 Modeling the Cooling Curve of Soy Oil . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Virtual Layout for Continuous Casting of Steel . . . . . . . . . . . . . . . . . . . . . .
1.6 Pore Clogging During a Long-Term Experiment with Bentonite Buffer Material: PoreSpace Percolation and Prediction of Air Permeability . . . . . . . . . . . . . . . . . .
1.7 A New Developped Method for the Optimization of the Adhesion Strength of Ceramic
and Metallic Coatings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.8 Automatic Ice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.9 Diagnostic Device for the Early-Stage Detection of Skin Cancer . . . . . . . . . . . .
1.10 Produktionskontrolle von Pulverbeschichtungen mittels thermischer Schichtprüfung .
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2 Fuel cells
2.1 Optimierung eines SOFC Brennstoffzellenmoduls . . . . . . . . . . . . . . . . . . . .
2.2 Leckagenanalyse im Hexis Brennstoffzellensystem . . . . . . . . . . . . . . . . . . .
2.3 Topological Analysis and FE-Simulation for the Study of Microstructure Degradation
in Solid Oxide Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Oxide Scale on Interconnectors after 40’000 Hours Fuel Cell Operation . . . . . . .
2.5 Relationships between 3D Topology and Reaction Kinetics in SOFC Electrodes . . .
2.6 Thin-Membranes Design in Micro-Solid Oxide Fuel Cell . . . . . . . . . . . . . . . .
2.7 Belenos Fuel Cell Stack: Simulation and Freezing . . . . . . . . . . . . . . . . . . .
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3 Energy Systems
3.1 Exploring and Improving Durability of Thin Film Solar Cells . . . . . . . . . . . .
3.2 Simulation of Hydrogen Production with a Photoelectrochemical Solar Cell . . .
3.3 Integration of High Temperature Electric Converter for Electricity Generation in
Solide Oxide Fuel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Thermofluiddynamische Modellierung von Biomassevergasung . . . . . . . . . .
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4 Organic Electronics
4.1 Light Outcoupling from Organic Light-Emitting Diodes . . . . . . . .
4.2 From Atoms to Large-Area OLEDs -the IM3OLED Project . . . . . .
4.3 Erweiterung der Laborinfrastruktur zur Herstellung von Organischen
am ICP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Leuchtdioden
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Appendix
A.1 Student Projects . . . . . . .
A.2 Scientific Publications . . . .
A.3 Book Chapters . . . . . . . .
A.4 News Articles . . . . . . . . .
A.5 Exhibitions . . . . . . . . . .
A.6 Conferences and Workshops
A.7 Prizes and Awards . . . . . .
A.8 Teaching . . . . . . . . . . .
A.9 ICP-Team . . . . . . . . . . .
A.10 Spin-off Companies . . . . .
A.11 Location . . . . . . . . . . . .
Institute of Computational Physics
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42
ZHAW
Vorwort
Was haben Brennstoff- oder Solarzellen mit Schokolade gemeinsam ?
Alterungsprozesse spielen bei der Erforschung neuer funktionaler Materialien eine zentrale Rolle.
Wenn es zum Beispiel darum geht, Brennstoffe, Wärme oder Sonnenlicht direkt in elektrische
Energie umzuwandeln, führen unerwünschte Alterungsprozesse häufig zu einer starken Abnahme
der Effizienz. Typischerweise zeigen sich diese Alterungsprozesse in Veränderungen der mikroskopischen Beschaffenheit der Materialien, der sogenannten Mikrostruktur.
Experimentell lassen sich sowohl Alterungsprozesse als auch die Leistungsfähigkeit von Materialien gut abbilden. Mit der Hilfe von Rasterelektronen- oder Focused-Ion-Beam-Mikroskopen
können 2D- oder 3D-Mikrostrukturaufnahmen erstellt werden. Und die Leistungsfähigkeit vieler
Materialien lässt sich über Impedanzspektrokopie ermitteln. Gilt es jedoch, quantitative Veränderungen in der Mikrostruktur mit der daraus resultierenden Verminderung der Leistungsfähigkeit
zu korrelieren, stösst die experimentelle Forschung an ihre Grenzen.
Hier kommen Computermodelle ins Spiel. Sie bilden die im Material ablaufenden Prozesse über
physikalische Modelle ab. Dabei werden Mikrostrukturaufnahmen als Input verwendet, um daraus die Performance des Materials vorherzusagen. So helfen Modelle, Alterungsprozesse besser
zu verstehen, Herstellungsprozesse zu optimieren und negative Materialeigenschaften von vornherein zu vermeiden. Das erklärt auch, was eine Brennstoff- oder Solarzelle mit Schokolade
gemeinsam hat: In all diesen Materialien laufen Alterungsprozesse ab, die von der Mikrostruktur
abhängen und über Computermodelle simuliert werden können.
Wie breit gefächert die Wissenschaftler des ICP forschen, erfahren Sie anhand des vorliegenden
Jahresberichts 2012.
Auch in diesem Jahr möchte ich an dieser Stelle allen Mitarbeitern unseres Instituts für ihr grosses
Engagement, ihre Begeisterungsfähigkeit und die tolle gegenseitige Unterstützung ganz herzlich
danken.
Thomas Hocker
Institutsleiter
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ZHAW
Preface
What do fuel cells, solar cells and chocolate have in common ?
Aging processes play a key role in the development of new functional materials. For example,
when converting fuel, heat or sunlight into electrical energy, undesirable aging processes often
result in a large decrease in efficiency. Typically, these aging processes show up on very small
scales within the materials, i.e. in transformations of its microstructure. Both aging processes and
performance losses can be monitored experimentally. Using scanning electron and focused ion
beam microscopy, 2D or 3D microstructure images can be taken. In addition, the performance
of many materials can be determined using impedance spectroscopy. However, purely experimental approaches are insufficient to correlate in a quantitative manner the observed changes in
microstructure to the resulting performance losses.
This is where our computer models come into play. Using these models we simulate the underlying
aging processes based on physical laws to predict the resulting performance of the materials
studied. Experimental microstructure data serve as input for the simulations. This way, modeling
and simulation help us to better understand the aging of the materials – whether it be fuel cells,
solar cells and chocolate. Anyway, as you will notice from the present Research Report 2012, our
research covers a broad range of exciting topics.
At this point, I would like to take the opportunity to thank all the colleagues of our institute for their
commitment, their enthusiasm and the great mutual support. Thank you very much.
Thomas Hocker
Head of ICP
4
ZHAW
1.1
Simulation von Personenströmen als Kontinuum bei Grossanlässen und dichtem Personenverkehr
Contributors:
R. Axthelm
Partners:
Funding:
Duration:
ASE GmbH
KTI
2013–2014
sonenbewegungen in grossen Dichten aufgestellt werden: Erstens wird die Geschwindigkeit
eines einzelnen Individuums durch die benachbarten Personen und das Verhalten der Menge
bestimmt. Zweitens haben die Fussgänger ein
gemeinsames Ziel, das sie verfolgen. Und drittens nähern sich die Fussgänger auf dem direktesten Weg ihrem Ziel, wobei sie grössere Personendichten zu vermeiden versuchen. Anhand
dieser drei Hypothesen lassen sich die Bewegung und die Dichteentwicklung der Menschenmasse als Kontinuum mit der folgenden Gleichung beschreiben %t + ∇ · (% u) = 0, wobei % für
die Dichte und u für die vektorielle Geschwindigkeit der Personenmasse steht. Die betragsmässigen Grössen der Geschwindigkeitsvektoren sind in Form von empirischen Daten (Fundamentaldiagramme, s. Fig. 2) gegeben. Die
Richtung wird dann durch Lage der Ziele und
die Dichteverteilung bestimmt. Zum Modellansatz dazu gibt es Varianten in der Literatur.
Fig. 1: Street Parade in Zürich 2012
(Quelle: http://www.streetparade.ch)
Die Simulation von Fussgängerströmen soll zukünftig helfen, Grossveranstaltungen, wie z.B.
die Zürcher Street Parade, so zu planen,
dass auch in Paniksituationen keine Menschen
zu Schaden kommen. Etablierte Multi-Agent
Methoden sind nur auf kleine Menschenansammlungen anwendbar. Besser geeignet sind
Kontinuums-Methoden, für die aber bisher keine kommerzielle Software erhältlich ist. Ziel des
Projektes ist deshalb die Entwicklung einer Kontinuum basierten Software und deren Validierung durch Video-Analysemethoden.
Der Anwendungsbereich solcher Simulationsrechnungen lässt sich nicht nur auf andere
Grossveranstaltungen wie z.B. Fussballspiele
erweitern, sondern auch auf Planungen und
Konzeptionierungen von Gebäuden wie Bahnsteige, Bahnhofs- oder Flughafenhallen.
Die Firma ASE ist spezialisiert auf videobasierte Erfassung von Personenströmen, agentenbasierte Simulation realistischer Szenarien
und die ereignisorientierte Simulation der Auslastung von Serviceplätzen. Solche sogenannte
mikroskopische Simulationen, die jeden Fussgänger einzeln darstellen, stossen bei hohen
Personendichten schnell an Grenzen, so dass
keine zuverlässige Analyse mehr möglich ist.
Makroskopische Modellansätze versprechen in
solchen Situationen bessere Rechenergebnisse. Bis heute ist aber keine kommerzielle Lösung verfügbar.
Der makroskopische Modellansatz von Personendichten basiert zum einen darauf, die Menschenmasse als Kontinuum anzusehen und
zum anderen auf drei Hypothesen die für Per-
Fig. 2:
(Quelle: Seyfried: Steps toward the fundamental diagram -
empirical results and modelling, 2007)
Qualitativ machen die theoretischen Ergebnisse der makroskopischen Modelle einen guten
Eindruck. Allerdings wurden noch keine Methoden entwickelt, diese Ansätze auch quantitativ
zu validieren. Für die praktische Anwendung der
in der Forschung erarbeiteten Methoden ist eine
softwaretechnische Umsetzung notwendig. Das
im Projekt zu erarbeitende Software Tool soll
dies ermöglichen. Zusätzlich wird der Ansatz im
Entwicklungsprozess an Hand von gemessenen
Personenströmen validiert werden.
5
ZHAW
Abschlussbericht,Sonderfinanzierung,der,SoE,
,
,
,
Titel:' Materialcharakterisierung'mittels'Ultraschall4Verfahren'für'die'
Prozessoptimierung'in'der'Lebensmitteltechnologie'
Research
Report 2012
Projektteam:' '
1.2
,
,
Thomas,Hocker,(ICP,,Projektleiter),
,
,
,
Materialcharakterisierung
in der Lebensmitteltechnologie
Olaf,Hoenecke,(IDP),
,
,
Josquin,Rosset,(ZSN),
mittels Ultraschall-Verfahren
,
,
Marcel,Rupf,(ZSN),
Adrian,Fassbind,(ZPP,,nachträglich,zum,Projekt,gestossen),
Contributors: T. Hocker
Regula,Kramer,(ZPP,,nachträglich,zum,Projekt,gestossen),
Partners:
IDP-ZHAW, ZSN-ZHAW, ZPP-ZHAW
,
Funding:
SoE-ZHAW
,
,
,
,
,
,
,
,
,
,
Duration:
2012
Gesteckten'Ziele'
Ziel
des Projekts ist die Entwicklung und Erpro- bensmittelprobe kann über ein Peltierelement
Ziel,des,Projekts,ist,die,Entwicklung,und,Erprobung,eines,„UltraschallQDemonstrators“,,mit,dem,im,
bung
eines Ultraschall-Demonstrators, mit dem im Temperaturbereich 10 – 60 °C aufgeheizt
Labor,in,Realzeit,die,Veränderung,von,Materialeigenschaften,von,Lebensmitteln,wie,z.B.,die,
imKristallisation,von,Schokolade,detektiert,werden,kann.,Hierfür,sollen,Ultraschallsensoren,in,
Labor in Realzeit die Veränderung von Ma- und abgekühlt und so ähnlichen thermischen
terialeigenschaften
von Lebensmitteln detek- Bedingungen wie in der Produktion ausgesetzt
verschiedene,Konfigurationen,und,Anregungsmoden,über,die,Auswertung,von,SchallgeQ
tiert
werden
kann
–
wie z.B. die Kristallisation werden.
schwindigkeiten,und,Schallabsorptionen,in,der,Lebensmittelprobe,auf,ihr,Potential,hin,untersucht,
von
Schokolade.
Hierfür
sollen Ultraschallsen- In ersten Versuchen wurde gezeigt, dass mit
werden.,
soren in verschiedene Konfigurationen und An- hochfrequentem Luftultraschall ein neues VerErreichte'Ziele'über die Auswertung von Schall- fahren für Top-Down Messungen über der Leregungsmoden
geschwindigkeiten und Schallabsorptionen in bensmittelprobe zur Verfügung steht (siehe
der Lebensmittelprobe auf ihr Potential hin un- Fig. 2). Dieses neue Verfahren vermeidet die
tersucht werden.
Schwierigkeiten einer konventionellen, direkten
Schallankopplung über flüssige oder feste Medien. Letztere dehnen sich in typischen Lebensmittelherstellungsverfahren aufgrund von Temperaturänderungen aus oder ziehen sich zusammen und verfälschen so die Messungen.
Der für Luftultraschall erforderliche Dynamikbereich von 120 dB konnte allerdings bisher nur
mit Laborgeräten mit entsprechender Sendeleistung und hoher Verstärkung der Empfangselektronik erreicht werden. Mit zusätzlichen Anpassungen der eingesetzten Wandler und der
Elektronik (kürzere Pulsdauer bzw. höhere Frequenz) wäre eine noch bessere Separation der
empfangenen Echos zu erzielen.
,
Fig. 1: Planung und thermische Auslegung des Fig. 2: Aufgebauter Ultraschall-Demonstrator und
Der,UltraschallQDemonstrator,konnte,entsprechend,der,gemeinsam,erarbeiteten,Vorgaben,realisiert,
Ultraschall-Demonstrators.
erste Messergebnisse. Das Ultraschallecho veränund,für,erste,Untersuchungen,genutzt,werden.,Die,Abbildung,zeigt,oben,links,das,am,ZPP,erstellte,
dert sich wähnend der Erstarrung der Schokolade.
Der
Ultraschall-Demonstrator konnte entspreCADQModell,basierend,auf,der,thermischen,Auslegung,am,ICP,(exemplarisch,unten,links,dargestellt),
chend der gemeinsam erarbeiteten Vorgaben Der Ultraschall-Demonstrator soll längerfristig
1, für den Einsatz in der studentischen
realisiert und für erste Untersuchungen genutzt sowohl
werden. Fig. 1 zeigt das am ZPP erstellte CAD- Ausbildung, als auch für MachbarkeitsanalyModell basierend auf der thermischen Ausle- sen als Basis für die Akquisition von zukünftigung am ICP und den Vorgaben an die Ul- gen Forschungsprojekten in der Lebensmitteltraschallsensorik von IDP und ZSN. Die Le- herstellung genutzt werden.
6
ZHAW
1.3
Neuartig optimierte Kühlprozesse zur nachhaltigen Herstellung von gefüllten Schokoladenprodukten mit verbesserter Qualität
Contributors:
L. Brenner, T. Hocker, T. Hunkeler, M. Suter
Partners:
Funding:
Duration:
IDP-ZHAW, ZSN-ZHAW, IFNH-ETHZ, Max Felchlin AG
KTI
2012–2015
Das Projekt COOLCON hat zum Ziel, eine neuartige in-line Messplattform (basierend
auf Ultraschall-, Temperatur- und Wärmeflusssensoren) in Kombination mit Multiphysik FEModellierung für die Analyse des transienten Erstarrungs- und Kontraktionszustandes
von Schokoladenprodukten zu entwickeln. Die
Messplattform und die Modelle sollen für die
Optimierung der Kühlung der Schokoladenprodukte in industriellen Kühltunneln eingesetzt
werden. Ziel ist die Verbesserung der Produktqualität unter gleichzeitiger Minimierung des
Kühlenergieverbrauchs.
In der Schweiz wurden 2010 176’424 Tonnen
Schokoladenprodukte hergestellt. Um diese in
Formen gegossenen Produkte in Kühlprozessen zur Erstarrung zu bringen, bedurfte es bei
einem Fettgehalt von ca. 30 % einer Kühlenergie von etwa 100 TJ (TeraJoule). Umfragen
in der Schokoladenindustrie haben zudem gezeigt, dass zur Sicherstellung einer guten Ausformbarkeit der Produkte als häufige Massnahme eine Verlängerung der Produktverweilzeit im
Kühlkanal um 20–40 % realisiert wird.
Jedoch kann bei Schwankungen in der Rohstoffqualität von Kakaobutter und entsprechenden Variationen in deren Kristallisationsneigung
auch das Problem einer zu kurzen Verweilzeit im Kühltunnel auftreten. Dies führt zu einer Verschlechterung der Ausformbedingungen
aufgrund einer unzureichenden Kontraktion des
Produktes in der Giessform und damit zu Fehlproduktchargen.
Deshalb soll durch eine Messdaten- und Modellbasierte Analyse der Kühlbedingungen und deren Auswirkung auf die Produktqualität der negative Einfluss von Schwankungen in der Rohstoffqualität minimiert und das grosse Energieeinsparungspotential besser genutzt werden.
Erste Messungen wurden im Kühlkanal der Max
Felchlin AG, Schwyz, durchgeführt. Fig. 1 zeigt
die Anordnung der verwendeten Temperaturfühler. Die Fühler wurden an verschiedenen Stellen in der Schokolade, der Form und der Umgebung platziert. Die resultierenden Temperaturprofile sind in Fig. 2 dargestellt.
Fig. 1: Anordnung der T-Sensoren in Schokolade,
Form und Umgebung.
Fig. 2: Abkühlkurven von Schokolade, Form und Umgebung im Kühlkanal.
Parallel dazu wurde das Abkühlverhalten der
Schokolade modelliert, siehe Fig. 3. Je nachdem, ob die Änderung der inneren Energie u
der Schokolade während der Erstarrung nur
von T , oder von T und der Kühlrate dT /dt abhängt, ergeben sich qualitativ unterschiedliche
T -Verläufe.
Fig. 3: Modellierter T-Verlauf der Schokolade im Kühlkanal.
7
ZHAW
1.4
Modeling the Cooling Curve of Soy Oil
Contributors:
M. Suter, T. Hocker
Partners:
Funding:
Duration:
Max Felchlin AG
ICP-ZHAW
2012–2013
The crystallization properties of fats determines
the melting behaviour, snap and gloss of chocolate and confectionery products. For a long
time, the ”Shukoff cooling curve method“ has
been applied in the food industry to analyze the
crystallization properties of fats. The Shukoff
method is a standardized procedure which describes the cooling of a properly melted fat in a
standardized glass flask with a vacuum jacket.
The glass flass is positioned in a water bath,
while the temperature of the fat is recorded with
a Pt100 temperature probe, see Fig. 1.
probe and for water bath temperatures of 0 and
10 °C, respectively. Note that the simulated
curve based on the global balance fits the data
better than the curve obtained from the FEmodel. This is because the global model contains an adjustable fit parameter which the FEmodel does not. Furthermore, the FE-model is
much more sensitive with respect to parameter
variations such as the thicknesses of the glass
walls of the used Shukoff flask, or the provided
initial conditions.
After the successful validation of both models
by experimental data, the main heat fluxes have
been calculated. In Fig. 3, you can see from
Jradiation,Wat that the thermal radiation between
the soy oil probe and the surrounding cooling
water is dominant – even at these rather low
temperatures.
Fig. 1: Shukoff flask with melted fat sample and Pt100
probe. (Note that the flask is actually positioned vertically in a water bath.)
Fig. 3: Heat fluxes between the soy oil probe and its
surroundings as obtained from the developed SESES
FE-model.
However, the non-negligible conductive heat
flux Jcon,Wat through the vacuum gap at vacuum
pressures around 1 Pa indicates the presence of
Fig. 2: Comparison of measured and simulated
heat transfer by Knudsen flow. Finally, it is obviShukoff cooling curves of soy oil for water bath temous from the behavior of JAmbient that at cooling
peratures of 0 and 10 °C.
times above 40 minutes, heat flows from the ambient air above the cooling water level into the
The objective of this work is to characterize probe. This leads to a stationary probe temperthe Shukoff apparatus from a thermodynamic ature which is above the cooling bath temperapoint of view. For this purpose, the cooling of ture, see Fig. 2.
soy oil has been modeled by global energy bal- In future work, our modeling approach will be
ancing and by solving the local heat conduc- extended to phase change materials such as
tion equation using our in-house multi-physics cocoa butter and to other cooling curve apparaFE-software SESES. Fig. 2 shows the good tus such as tempermeters. This will help to betagreement between the measured and simu- ter understand the complex crystallization belated cooling curves for the considered soy oil havior of chocolate and confectionery products.
8
ZHAW
1.5
Virtual Layout for Continuous Casting of Steel
Contributors:
G. Sartoris
Partners:
Funding:
Duration:
SMS Concast, Numerical Modelling GmbH
CTI
2012–2013
SMS Concast is an engineering company supplying heavy machinery and related technology
for the production of long steel products as billets and blooms, which are subsequently transformed by rolling or forging into semi-final products. SMS Concast is selling combi continuous
casters by exploiting its lead in casting process
know-how and innovative customer-specific design solutions. The core components relevant
for the steel-making processes as melting, refining and casting are designed and developed
in Zürich and Udine (Italy). The scope of supply of SMS Concast comprises design, engineering and automation, supply of hardware,
commissioning of single process elements up to
complete melt-shops. Such melt-shops range
in their capacity from ca. 150.000 tons/year
up to 2.3 million tons/year for one process-line.
The company is acting world-wide and operates in the growth markets for steel with its
own 100% owned daughter companies in Brazil,
North America, Italy, India, China, Thailand and
at European locations in England and Spain.
fort and deploy it already in the offering phase.
In addition, it will support R&D by identification of casting process limits and troubleshooting during installation and the after sales phase.
The continuous casting of steel includes a liquid phase inside the moving slab and a solidifying one at the exterior. The liquid phase
can display a turbulent character whereas the
solid one is subjected to elasto-plastic deformations. The strand is moving in a stationary way
through rollers and at the same time is cooled
by sprayed water. Numerical methods have to
cope with solid and fluid phases transport, energy transport, mechanical contacts, radiation
and cooling. Here a mixed Euler-Lagrange formulation should be used to model this multiphysics problem, the former one is the method
of choice for fluids and the latter one for solids.
The challenging task is the capability to correctly track the evolution of the surface showing
the phase transition, in short front tacking. A
coupled thermal-mechanical computation is required here with an enthalpy function strongly
non-linear at the phase transition. The solidified portion of the slab undergoes large plastic deformations and grows inwards from a thin
layer to the full solid slab. For modeling the mechanical behavior of thin structures, shell elements are generally preferred. However, since
the slab’s walls are standing growing in thickness, at some point one has to switch to generic
solid elements, because the shell hypothesis is
not valid anymore. To avoid this critical switching, one can opt to use stabilized solid elements
of first order from the beginning.
Goal of this project is to provide the industrial
partner SMS Concast with up to date software
for modeling the continuous casting of steel.
In particular, our aim is to improve and adapt
the NM-SESES multiphysics software to stateof-the art numerical algorithms as required for
running optimized computations in the layout of
continuous casting machinery. The NM-SESES
software is already an advanced numerical tool
for multiphysics modeling. It can solve in a coupled way almost all conservation laws of classical physics with generic coupling terms and
material laws defined by the user as part of
the problem specification. However, due to the
complexity of the problem at hand, the problem
specification for the continuous casting model
is becoming a rather involved task. With this
project, SMS Concast plans to improve the numerical simulation know-how developed in collaboration with NM Numerical Modelling GmbH
during the past years. Optimized models and
simulation concepts for the moving strand approach will enable SMS Concast to simulate
casting processes closer to reality, with less ef-
Fig. 1 Steel blooms produced by SMS Concast continuous casters.
9
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1.6
Pore Clogging During a Long-Term Experiment with Bentonite Buffer Material: Pore-Space Percolation and Prediction of Air Permeability
Contributors:
L. Keller, L. Holzer
Partners:
Funding:
Duration:
EMEZ-ETHZ (P. Gasser), EMPA (M. Rossell, R. Erni)
NAGRA, SHARC
2012
Low-permeability geomaterials such as clay
rocks and betonites are potential seal materials that should guarantee the safety of radioactive waste depositories. In addition, such geomaterials are reservoirs of natural gas, which
were increasingly exploited during recent years.
Therefore, gas flow properties of such materials
are of prime importance because, for example,
gas pressure form corroding steel in radioactive
waste depositories should be released via the
intergranular pore space. Thereby, one of the
most fundamental question is, at what properties (e.g. porosity) gas can flow trough the pore
space and arrive at the other side of the system. By using a combination of high-resolution
tomography, local porosity theory1 and classical percolation theory we provided information
on fundamental transport properties such as
the percolation threshold2 . In the following we
present results related to one of the case studies that where performed at the ICP. The examined bentonite samples are from the longterm experiment, which simulates the behaviour
of different seal materials under conditions of a
high level radioactive waste depository.
The microstructure analyses document that extensive precipitation of amorphous material led
to substantial changes of the pore structure. Energy dispersive X-ray spectroscopy performed
in a transmission electron microscope shows
that the amorphous material is enriched in Fe,
Ca and Si, which indicates that Fe released from
corroding steel reacts with dissolved species
from the buffer material. Initially the porosity in
the bentonite was in the range of 4.3–4.6 vol. %
but due to precipitation and pore clogging the
open porosity was reduced to < 1 vol. %.
Focused ion beam tomography in combination
with a finite scaling approach was applied to the
resolved pore space, which yielded percolation
thresholds with critical porosities φc (Fig. 1).
After precipitation the residual open porosity is
far below the percolation threshold. The original porosity of one sample was above the percolation threshold, but also in this material the
percolation is restricted to one spatial direction.
This indicates an anisotropy with respect to percolation. Obviously, precipitation of new phases
leads to pore clogging, which in turn affects gas
permeability. Using results from pore-network
modelling3 in combination with percolation theory illustrates that a minor reduction of porosity
leads to a to substantial decrease in gas permeability. Depending on water saturation, air permeability decreases exponentially over three to
four orders of magnitude within a narrow porosity range of about 1 vol. % (Fig. 2).
Fig. 1: Determination of percolation threshold φc Calculation of finite-size percolation probabilities λ(φ, L)
are based on reconstructed pore spaces that were
obtained from of FIB tomographic data. (a) Measuring pore connectivity in cells of different sizes L
allows calculating finite-size percolation probabilities.
(b) finite scaling of φmax (i.e. point inflection of λ(φ, L)
with L−1/ν yielded percolation thresholds along different directions.
10
ZHAW
tion S. The absolute permeability k0 and the critical
volume fraction c for air percolation was calculated
on the base of two-phase flow network modelling. (b)
and (c) are illustrations of two principle steps in the
network modelling workflow. (b) 3D reconstruction
of the pore space after segmentation based on FIBnt. (c) Representation of the extracted pore network
(also called skeleton), which is topologically equivalent to the segmented pore space in (b). Red balls
correspond to pore bodies whereas grey sticks correspond to the pore throats.
Based on observations and calculations, gas
transport along the integranular pore space of
bentonites is not considered as a possible scenario and can reasonably be excluded for the
residual open porosity after segregation of new
phases.
Fig. 1: Prediction of gas permeabilities related to a
pore space that is affected by changing porosities due
to segregation of new phases. (a) Gas permeabilities
ka (φ) calculated for different values of water satura-
Literature:
1
Hilfer, R. 1991, Physical Review, 44, 60-75.
2
Keller et al. (subm.), J. Geophys. Res.
3
Valvatne, P. H., Blunt, M.J., 2004. Water Resources Research, 40, W07406.
11
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1.7
A New Developped Method for the Optimization of the Adhesion Strength of Ceramic and Metallic Coatings
Contributors:
Y. Safa, G. Sartoris, T. Hocker
Partners:
Funding:
Duration:
IMPE-ZHAW (M. Terner, D. Penner, Ch. Scherrer, A. Jung)
SoE–ZHAW
2012–2013
Thermal barrier coatings (TBC) are an essential technology in many industrial applications,
from “macro applications” such as the ceramic
coating on the metallic blades in gas turbines
to MEMS (Micro-Electro-Mechanical-Systems)
thin film deposition. Failure of such coatings occurs often at the coating-substrate interface.
Several experimental testing (shearing, tensile,
or bending tests) have been suggested to evaluate the adhesion strength of the coats. Such
methodes, however, are not applicable in general, especially for the evaluation of the remaining interfacial strength of actual coated components in gas turbine, because of the requirement
of relatively large specimen.
An alternative non-destructive test is based on
indentation (by Vicker or Knoop) applied on
the interface of “small” coat-substrate sample.1
Moreover, the fracture toughness of the coat
which is represented by the stress intensity factor Kc is obtained using empirical formulation
with fitted parameters. An open question is still
the applicability of such a semi-empirical approach for different material and loading conditions.
The main objective of this project is to develop a
relevant material model to assess the intarface
fracture toughness using physical parameters
measured via X-ray diffraction (XRD), indentation testing and sophisticated numerical tools for
the simulation of contact mechanics and crack
propagation in various coating-substrate systems provided by current or past research partners. This is divided into three work packages:
WP1- Indentation tests at the coating-substrate
interface to produce cracking and provide a
depth-load dependency, followed by microscopic imaging of the indented samples.
WP2- XRD measurement of residual stress in
these samples.
WP3- Set up a numerical contact mechanics
model (FEM) and a numerical crack propagation model by applying XFEM (eXtended Finite
Element Method) and using input material data
from WP1 and WP2.
Fig. 1: A road map for search space
X-ray diffraction using a new 1/4 circle Eulerian
Cradle was used for residual stress (RS) analysis of the samples. The measurement parameters were established and good residual stress
values were obtained for PVD-ZrN, TBC bondcoat layer, and welded Stellite 712 on steel. No
significant residual stress was found in the top
surface of the TBC ceramic YSZ layer, however
the geometry did not allow accurate measurement at the interface. HOVF Cr2C3-NiCr hard
coatings were not suitable for this XRD analysis.
Fig. 2: XRD spectra for YSZ coating: except for the
1 bondcoat peak indicated, all peaks are YSZ or
substrate. Theoretical bondcoat peak positions are
shown by green markers. (Performed at LKM by M.
Terner)
A new indentation method is developed at the
laboratory of metallic material LMM to perform
12
ZHAW
indentation tests along coating-substrate interfaces from 5 to 500 N, with both Knoop and
Vickers indenters. The HOVF Cr2C3-NiCr hard
coating was the most successful system tested,
whereas the TBC and Stellite system could not
produce reliable information.
Fig. 5: The results obtained at ICP are in agreement
with experimental data at IMPE
Fig. 3: 3D confocal microscope image of indentations taken with Leica DCM 3D. The indentation is
applied at the interface between YSZ coat and steel
substrate using a Vickers indenter, for 14 micrometer
depth. (Performed at LMM by Ch. Scherrer)
A contact mechanics model based on the FEM
software SESES developed at ICP was extended to indentations on a bimaterial interface.
The numerical simulation was validated, since
the obtained load-depth data are in good agreement with the values provided by indentation on
superalloy sample.
Fig. 4: Simulation of superalloy sample under Vicker
indentation using in-house developed SESES code.
A plastic deformation is shown in unloading stage
The resulting contact stress fields were successfully used to predict the crack initiation and
propagation and to evaluate the fracture toughness in an advanced simulation based on XFEM
(implemented in GetFEM package), see Fig. 6.
Fig. 6: Interface indentation crack in slice view: Simulation using XFEM and visualization using Paraview
Perspective:
An implementation of advanced enrichment
techniques in XFEM code representing the bimaterial interface crack should allow more accurate representation of the stress field in delamination problem. An iterative coupling of the
solving step for crack growth and the contact
solution at given indentation depth step should
be a highly sophisticated approach of the crack
growth under indentation. The fracture mechanics results obtained by solving a dynamic crack
growth problem can be compared to the experimental data when acoustic emission techniques
are synchronized with operational time step of
the indentation machine.
Literature:
1
Yamazaki et al., Acta Metall. 24, No. 2, 109117 (2011).
13
ZHAW
1.8
Automatic Ice
Contributors:
R. Ritzmann
Partners:
Funding:
Duration:
ZPP-ZHAW
Altira GmbH
2012–2013
In einer Vorarbeit wurde ein LED Bildschirm
zum Einbau in Eisfelder von Eishockeyarenas
entwickelt. Der Einbau und der damit verbundene schichtweise Eisaufbau, erwies sich
aber als aufwändiger und lange andauernder
Prozess. Die damit betrauten Mitarbeiter haben
lange in der Kälte auszuharren.
Um den Vorgang zu automatisieren wurde in
Zusammenarbeit mit dem ZHAW internen Zentrum für Produkt- und Prozessentwicklung ein
serienreifer Automat erstellt (siehe Fig. 1).
keine Lufteinschlüsse und keine sichtbaren
Schichtübergänge im fertigen Eis.
Die Anlage wird zur Zeit im OLAB auf einer
umgebauten Eiskühltruhe unter ähnlichen Bedingungen wie in der Eishalle betrieben um die
Sensorik und Parameter zu optimieren (siehe
Fig. 2).
Fig. 1: 3D Kontruktion, kompaktes Eis System zum
automatischen Aufbau von klarem Eis
Automatic Ice enthält eingebaute Heiz- und
Kühleinheiten und kann Luft und Wasser in
vordefinierten Abläufen ins Eisloch spritzen.
Zuerst wird das Eis auf eine definierbare
Tiefe abgeschmolzen und anschliessend
schichtweise innerhalb von 4 mm/h wieder
aufgebaut.
Den hohen Ansprüchen an die Eisqualität
wird dabei Rechnung getragen. Es gibt also
Fig. 2: Labortests für optimierten Parametersatz
Mit Automatic Ice werden die LED-BildschirmModule oder auch Markierungen schnell einund ausgebaut.
Zusätzlich bietet es auch
die Möglichkeit defekte Stellen, wie sie z.B.
im Bereich der Eishockeytore häufig auftreten,
über Nacht reparieren zu können.
14
ZHAW
1.9
Diagnostic Device for the Early-Stage Detection of Skin
Cancer
Contributors:
M. Bonmarin
Partners:
Funding:
Duration:
Dermato Oncological Unit – HUG
Swiss Cancer League
2012–2014
Incidence of skin cancers is very high in Switzerland and rising worldwide. Their prognosis depends on the precocity of diagnosis. Currently,
the detection of skin cancer is essentially clinical and largely depends on the expertise of the
clinician. Though, as early tumors often lack of
specific signs, many benign lesions are excised
to be on the safe side. Moreover, some skin cancers do not have visible limits, which can induce
complex or multistep surgery. Therefore, detection and treatment of these tumors generate big
health costs.
Compared to benign lesions, malignant tissues
are expected to demonstrate specific thermal
properties that can be exploited to refine their diagnosis. For example, a higher metabolic activity and a higher perfusion are anticipated at the
location of the cancerous lesion. Such thermophysical variations can be accurately detected
using active thermography based setups.
In close collaboration with the Geneva University Hospital (HUG), we develop a new highly
sensitive infrared imaging technique for the detection of skin cancers. We plan to test this
technique in order to define its actual limitations.
The device is based on the lock-in thermography method: skin surface temperature is periodically modulated by forced convection, while a
highly sensitive infrared imaging device records
its thermal emission (see Fig. 1 A)). Infrared images are then processed to a computer according to the digital lock-in principle. We expect that
the amplitude and phase images resulting from
this demodulation can be correlated to the le-
sion malignancy.
The first prototype developed in our laboratory
(see Fig. 1 B)) shows promising results. An improved version will be tested in a clinical environment in summer 2013 at the University
Geneva Hospital to evaluate the potential of the
method.
Fig. 1: A) Pictorial description of the lock-in thermography setup. B) First Dermolockin prototype developed in our laboratory
15
ZHAW
1.10
Produktionskontrolle von Pulverbeschichtungen mittels
thermischer Schichtprüfung
Contributors:
N. Reinke
Partners:
IDP-ZHAW, IGP-ZHAW, Winterthur Instruments AG, J. Wagner AG, Ronal AG,
Ernst Schweizer AG, Ramseier Woodcoat AG (Ru)
KTI
2012–2013
Funding:
Duration:
Pulverbeschichtungen zeichnen sich besonders
durch Korrosionsbeständigkeit und Kratzfestigkeit aus. Sie sind lösungsmittelfrei und werden
besonders ressourcenschonend aufgebracht.
Schwer kontrollierbare Prozessparameter wie
die elektrostatische Feldverteilung, Umgebungstemperatur und die definierte Körnigkeit des
Pulvers wirken sich auf die Beschichtungsdicke
aus, die bislang nur nach dem Einbrennvorgang
zuverlässig geprüft werden kann. Verschwendung von Ressourcen und Beschichtungsfehler sind die Folge einer fehlenden Prozessprüfung bei der Beschichtung. Hohe Einbrenntemperaturen und -zeiten verursachen zudem hohe
Energiekosten. Dadurch wird die Wirtschaftlichkeit von Pulverbeschichtungen im erheblichen
Masse beeinträchtigt.
schichtungsanlagen, eine bessere Auslastung
des Personals, eine Reduzierung der Beschichtungsdicke auf das Optimum und eine 100%
Qualitätskontrolle. Das Messystem hilft das Verständnis des Einbrennvorgangs zu verbessern
und ist damit ein Grundstein für ökonomisch
und ökologisch optimierte Pulver mit verringerten Einbrenntemperaturen und effizienteren
Einbrennprozessen. Als Grundlage für dieses
Messsystem soll eine funktionstüchtige Pilotanlage entwickelt und deren Praxistauglichkeit bei
Anwendungspartnern getestet werden.
Fig. 2: CoatMaster bei der Inline-Schichtdickenmessung von Pulverbeschichtungen.
Fig. 1: CoatMaster Messsystem.
Im Rahmen dieses Projekts soll ein marktnahes Messsytem entwickelt werden, welche eine Kontrolle der Beschichtungsdicke vor dem
Einbrennen sowie des Gelier- und Aushärtegrads in der Produktion erlaubt. Dieses Messsystem erlaubt verkürzte Einfahrzeiten von Be-
Das Projektkonsortium umfasst die gesamte
Wertschöpfungskette der Pulverbeschichtungsindustrie: Hersteller von Pulverlacken, Anlagenbauer, Messgerätehersteller, sowie die Anwender. Im Anschluss an das Projekt sollen Feldtests bei den Industriepartnern durchgeführt
werden. Die Erkenntnisse dieser Feldtests fliessen in die Weiterentwicklung des Messsystems
ein.
16
ZHAW
2.1
Optimierung eines SOFC Brennstoffzellenmoduls
Contributors:
T. Hocker, C. Meier
Partners:
Funding:
Duration:
IEFE-ZHAW (P. Diggelmann), Hexis AG
Bundesamt für Energie, Swiss Electric Research
2012–2014
Zur Reduktion von Material- und Montagekosten entschied sich die Firma Hexis AG zur
Neukonstruktion ihres Brennstoffzellenmoduls
(BZM). Dabei stand nebst der Vereinfachung
der Konstruktion auch die Verbesserung der
Temperaturverteilung im Zentrum.
In das Hexis-BZM sind nebst den elektrischchemischen Komponenten (Zellstack und Reformer) auch wärmetauschende Elemente integriert, welche die Betriebstemperatur sowie
die Temperaturgradienten an der Zelle kontrollieren. Durch diese Bauweise kann das HexisSystem zwar kompakt gebaut werden, dafür
sind die auftretenden Wärmeströme schwerer zu verstehen und zu kontrollieren. Die
thermisch-fluidische Auslegung des neuen Designs wird deshalb vom ICP, zusammen mit
dem Institut für Energiesysteme und FluidEngineering (IEFE) der ZHAW, durch Modellbildung unterstützt.
In der Konzeptphase konnten wir durch die
Analyse der Massen- und Energieströme, die
Charakterisierung der wesentlichen Systemkomponenten sowie die Abbildung des BZMinternen Wärmetauschernetzwerkes einen optimalen Betriebspunkt identifizieren. In einem
nächsten Schritt erstellte das IEFE eine dreidimensionale Strömungssimulation, welche die
Firma Hexis experimentell validieren konnte. Dieses numerische Modell berechnet das
Strömungs- und das Temperaturfeld unter Berücksichtigung von Strahlungswärmetransport.
Der Brennstoffzellenstack wird optimal bei einer Temperatur von 850 ◦ C betrieben. Bei höheren Temperaturen führen Alterungsprozesse
zu einer erhöhten Degradation des elektrischen
Wirkungsgrades, während bei niedrigeren Temperaturen die inneren elektrischen Widerstände der Zellen sehr hoch sind. Deshalb sollte
auch die axiale Temperatur-Ungleichverteilung
("T-Bauch") vermindert werden (siehe Fig. 1),
um den ganzen Stack im optimalen Temperaturfenster betreiben zu können.
Anhand der Simulation des Ist-Zustandes konnten wir zeigen, dass der T-Bauch wesentlich
durch die Führung der Verbrennungsluft beeinflusst werden kann. Zusammen mit Hexis
haben wir eine Vielzahl an Designs entworfen, simuliert und optimiert. Ende 2012 wurde das vielversprechendste Konzept an einem
Versuchsaufbau getestet. Trotz einer wesentlich
einfacheren Konstruktion resultierte eine Reduktion des T-Bauches von rund 60 %. Gleichzeitig verbesserte sich die Effizienz der thermischen Isolation markant.
Fig. 1: Temperatur-Plots der Referenz- und einer optimierten Variante. Der Zellstack der optimierte BZMVariante weist einen geringeren Temperatur-Bauch auf.
17
ZHAW
2.2
Leckagenanalyse im Hexis Brennstoffzellensystem
Contributors:
L. Kaufmann
Partners:
Funding:
Duration:
Hexis AG
Swiss Electric Research, Bundesamt für Energie
2012–2014
(<1000 h) Zellen mit einer definierten Vorschädigung in Form von Schlitzen und Brüchen
mit intakten Zellen verglichen. Zur Charakterisierung des Zellverhaltens wurden StromSpannungskennlinien aufgenommen. Es zeigt
sich, dass zur Detektion eines Zelldefekts ganze
Strom-Spannungskennlinien betrachtet werden
müssen. Es reicht nicht aus, einzelne Merkmale wie zum Beispiel die Ruhespannung (OCV)
zu betrachten. Leichte Zelldefekte wie einfache
Risse lassen sich im Hexis-System in der Regel nicht über Strom-Spannungskennlinien detektieren. Bei schweren Schädigungen (0.8 mm
breite Schlitze) sind die Auswirkungen auf die
Kennlinien deutlich erkennbar.
Ruhespannung
1100
intakteZelle
ZellemitSchlitz
1000
Spannung/mV
Die Hexis AG in Winterthur (ehemals Sulzer Hexis) entwickelt ein mit Erdgas betriebenes Hochtemperaturbrennstoffzellensystem
vom Typ SOFC (Solid Oxide Fuel Cell) zur stationären Strom- und Wärmeerzeugung in Einfamilienhäusern. Die Langlebigkeit und Zuverlässigkeit dieses Systems hängt unter anderem
massgeblich von der Stabilität der zur elektrischen und thermischen Energieerzeugung verwendeten Brennstoffzellen ab. Für stationären
Brennstoffzellensysteme ist ein entscheidender
Erfolgsfaktor das Erreichen der geforderten Lebensdauer von 40’000 Betriebsstunden. Im Betrieb werden Brennstoffzellen durch thermische,
chemische und auch mechanische Belastung
beansprucht. In Folge dessen nimmt der elektrische Wirkungsgrad des Systems mit zunehmender Betriebsdauer ab. Diese Leistungsdegradation wird beschleunigt, wenn eine Leckage, z.B. durch eine defekte Dichtstelle oder
einen Zellriss, auftritt. Dies kann auch kurzfristig
einen Einfluss auf die Leistung des Brennstoffzellensystems haben.
900
800
700
600
500
0
5
10
15
20
25
Strom/A
Fig. 2: Vergleich der Strom-Spannungskennlinien von
intakten und vorgeschädigten Zellen. Die intakte Zelle weist eine deutlich höhere Ruhespannung auf als
die Zelle mit Schlitz. Zudem fällt die Kennlinie der
vorgeschädigten Zelle steiler ab, was sich negativ
auf den Innenwiderstand der Zelle auswirkt.
Fig. 1: Brennstoffzelle mit Vorschädigung. Der Zelle wurde ein radial verlaufender Schlitz hinzugefügt.
Dies ist eine extreme Schädigung. Es ist unwahrscheinlich, dass im Betrieb so starke mechanische
Schäden auftreten.
Um herauszufinden, wie sich mechanische Zellschädigungen auf das Verhalten des Systems auswirken, wurden in Kurzzeitversuchen
Im Betrieb kann davon ausgegangen werden,
dass keine Schädigungen dieses Ausmasses
(Schlitze von 0.8mm Breite) bei Zellen auftreten.
Es bleibt festzuhalten, dass diese Aussagen nur
für Kurzzeitversuche zutreffen. In Langzeitversuchen ist zu erwarten, dass durch die Defekte verstärkte Zellschädigungen wie z.B. Delamination und/oder übermässige Degradation der
Elektroden auftreten und somit die Leistungsdegradation merklich zunimmt.
18
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2.3
Topological Analysis and FE-Simulation for the Study of
Microstructure Degradation in Solid Oxide Fuel Cells
Contributors:
L. Holzer, L. Keller, O. Pecho, M. Neumann, T. Hocker
Partners:
Funding:
Duration:
Hexis SA, EMPA, EMEZ-ETHZ, FZ-Jülich (De), Ulm University (De)
EU-FP7 (Project: SOFC-life)
2012–2014
Solid Oxide Fuel Cell (SOFC) systems represent an environmentally friendly energy technology that efficiently converts chemical energy
from natural gas into electricity and heat. In order to be economically profitable a service life
of 40’000 hours must be reached. The complex
phenomena of materials degradation are investigated in the SOFC-life project by a European
consortium, which consists of 20 academic and
industrial partners. The aim of the project is to
gain an improved understanding of the degradation mechanisms on a microscopic scale and
of their impact on cell and stack performances
on a macroscopic scale. This will enable to improve durability, which also leads to a higher
profitability. In this project, the ICP is working
on the quantitative 3D characterization of the
electrode microstructure. The ICP also deals
with the challenging task, how this microstructure information can be incorporated into a simulation framework that allows prediction of the
long-term degradation behavior.
Fig. 1: Illustration of microstructure degradation in
a fine-grained Ni-YSZ anode upon redox cycling at
900 ◦ C. The effective ionic conductivity is the product of the intrinsic conductivity multiplied by the microstructure factor (σef f = σ0 M ). The M-factor itself
is the product of four distinct topological parameters
(M = φP βτ −1 ). The most significant microstructure
effect in this case is a significant drop of the constriction factor (β), which strongly affects M and σef f .
In order to understand microstructure effects
related to electrode degradation it is necessary to identify all topological features, which
have a significant influence on the cell performance. For this purpose dedicated techniques
for 3D analysis including image modeling and
nanotomography were developed over the last
years. Fig. 1 illustrates the topological changes
in YSZ of a Ni-YSZ anode before and after redox degradation. In each phase the effective
transport properties (i.e. electronic conductivity in Nickel, ionic conductivity in YSZ, gas diffusion in the pores) depends on four distinct
parameters: phase volume fraction, percolation factor, tortuosity and constrictivity. Surprisingly, the ionic conductivity drops significantly
upon redox cycling due to a decrease of the
constrictivity in the YSZ phase. This new phenomenon has not been documented in literature
and the perception of it was only possible with
new 3D-techniques.
In a second step the topological information is
incorporated into a finite element model (FEM).
The detailed 3D analysis tools provide a quantitative description not only of time dependent
degradation of the bulk electrode, but also of
the local microstructure variations within different domains of the electrodes. For example the above-described constrictivity parameter
only becomes important for transport distances
larger than a few microns, but it has no effect
at short distances. In the FE-simulation the distinction of such short and long rang effects has
a significant influence on the current distribution
close to the electrode-electrolyte interface and
on the corresponding cell performance (ASR).
In summary, the combination of 3D-topological
analysis with FE-modeling provides a unique
framework for the realistic simulation of SOFC
degradation.
These methodologies provide
novel insight on fundamental degradation mechanisms, which is necessary for further improvements of the long-term service life of the solid
oxide fuel cell system.
Literature:
L. Holzer et al., J. Mat. Sci. 48, 2934-2952,
2013.
L. Holzer et al., J. Power Sources (in press),
2013.
G. Gaiselmann et al., Comp. Mat. Sci. 67, 4862, 2013.
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2.4
Oxide Scale on Interconnectors after 40’000 Hours Fuel
Cell Operation
Contributors:
M. Linder, L. Holzer, T. Hocker
Partners:
Funding:
Duration:
Hexis SA
Swiss Electric Research, Swiss Federal Office of Energy
2012–2014
To provide a technical relevant amount of electrical energy several fuel cells have to be stacked.
These cells are connected in series with metallic interconnects (MICs) which act as gas separators and distributors for cathode air and anode fuel as well as current collectors from these
electrodes (cf. Fig. 1). Interconnects have to
fulfill different material requirements such as excellent oxidation and corrosion resistance and
high electric conductivity. Under solid oxide fuel
cell (SOFC) operating condition with high temperature (> 600 ◦ C), wet and carbon containing
atmospheres the oxide scale formation is continually promoted.
LSM coating
cathode side air channels (O2, N2)
cathode
Cr2O3 scale
Cr5FeY2O3 (CFY)
Cr2O3 scale
Ni mesh
anode
anode side fuel channels (H2, CO, H2O, CO2, N2, CH4)
Fig. 1: MIC configuration within a SOFC-stack. On
the anode side the Cr2 O3 formation takes place at
the bare surface and on the cathode side between
the alloy and LSM-coating.
The ohmic resistance caused by Cr2 O3 scale
formation on metallic interconnects can significantly contribute to the overall degradation of
SOFC stacks. For this reason oxide scale
growth on Cr5Fe1Y2 O3 (CFY) was investigated
by scanning electron microscopy (SEM) from
post-test samples that were operated in Hexis
planar SOFC-stacks under dual atmospheres
(i.e. anode and cathode conditions) at temperatures around 900 ◦ C. The study includes unique
test results from a stack operated for 40’000
hours. To analyze the inhomogeneity in scale
thicknesses a dedicated statistical image analysis method has been applied (cf. Fig. 2).
Fig. 2: (Top) SEM image of a cross section of a
metallic interconnect after 2’000 h exposure (850 ◦ C
in air). The perimeter of the Cr2 O3 scale is marked
by a red contour line. (Bottom) From the segmented
and binarized SEM image a mean scale thickness is
calculated.
SEM images were as well used to compare
the qualitative micro-structural phenomena related to MIC oxidation at different sample locations. The observed differences between different sample locations may relate to locally different conditions such as temperature and water
content. The Cr2 O3 scale growth on the anode
side is found to be approximately twice as fast
in comparison to the scale growth on the cathode side. Finally, based on our time lapse analyses with extensive sampling it can be concluded
that reliable predictions of scale growth requires
statistical analyses over a period that covers at
least a quarter (i.e. 10’000 hours) of the required
SOFC stack life time (40’000 hours).
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2.5
Relationships between 3D Topology and Reaction Kinetics
in SOFC Electrodes
Contributors:
O. Pecho, L. Holzer, T. Hocker
Partners:
Funding:
Duration:
IfB-ETHZ, NonMet-ETHZ, EMEZ-ETHZ, Hexis AG, EMPA, Ulm University (De)
Swiss National Science Foundation
2012–2014
Solid oxide fuel cells (SOFC) represent an
attractive, alternative energy technology due
to the combination of its high efficiency and
fuel flexibility. This project investigates the
microstructure-performance relationships, in order to establish criteria for new microstructure
concepts of improved SOFC electrodes. This
goal requires an interdisciplinary approach involving: (a) electrode fabrication with controlled
variation of the microstructure; (b) quantitative
analysis of microstructure involving first and
higher order topological parameters; (c) experimental characterization of macroscopic properties focused on the electrochemical performance; and (d) FE modeling of the electrode
reaction mechanism including the simulation of
combined effects from local morphology (microstructure) and from intrinsic material properties (e.g. surface exchange kinetics).
Fig. 1: Microstructures obtained at different sintering
temperatures, which lead to variations in grain and
pore size, surface area and associated electrochemical performance.
In the first period of the project, thin nanoporous
cathodes consisting of (La,Sr)CoO3 (LSC) were
successfully produced with the cost-effective
spray pyrolysis. LSC is a mixed ionic and
electronic conducting material (MIEC) that is
particularly suitable for intermediate- and lowtemperature SOFCs. Overall, the LSC cathodes
exhibit a very good performance, which is attributed to the nanostructure with small particle
size and well-distributed porosity. This is favorable for oxygen exchange at the LSC/air inter-
face, which is believed to be the rate determining process. Figure 1 illustrates LSC cathodes
with different microstructures. In order to better
understand the complex relationship between
microstructure and electrode performance, the
experimental investigations are combined with
3D analysis and with numerical simulations.
First order topological parameters (e.g. particle size distributions (c-PSD), volume fractions,
and surface areas) are determined based on
2D SEM imaging. For higher order topological parameters, (e.g. percolation factor, constrictivity, tortuosity) 3D information is needed.
FIB-tomography, which is the most suitable 3Dtechnique for this purpose, is time consuming
and the number of 3D analyses is limited. In order to acquire 3D topological information for a
large number of different microstructures, new
approaches based on the combination of 2D
imaging and stochastic 3D simulation are currently developed for this study in collaboration
with Empa and Ulm University.
In the present project the reaction mechanism of
an existing FE-model at ICP is adapted for MIEC
materials. For the simulation of microstructure
effects, input is used from microstructure analysis (i.e. surface area, TPB, tortuosity, constrictivity) and the effective transport properties.
Special techniques were developed, which allow
the determination of effective transport properties from topological analysis because the experimental measurement is often very difficult
(e.g. ionic conductivity of MIEC materials or gas
diffusivity in nanoporous thin films). In this way
different scenarios for microstructure effects can
be simulated in a realistic way, which helps to
understand the complex pattern revealed by the
experimental investigations.
In summary, the combination of experimental investigations together with 3D-imaging, stochastic simulations and numerical modeling opens
new possibilities to make links between topology, fabrication parameters and electrode performance. These methods shall thus be applied
in the next phase of the project for the improvement of LSC cathodes as well as for other composite electrodes.
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2.6
Thin-Membranes Design in Micro-Solid Oxide Fuel Cell
Contributors:
Y. Safa, T. Hocker
Partners:
Funding:
Duration:
NIM-ETHZ, LTNT-ETHZ, CSEM, SAMLAB-EPFL, MNT-NTB
Swiss National Science Foundation
2010–2012
Since more than 10 years, a consortium of research groups from five Swiss centers have
been involved in the development of µSOFC as
“small" energy converter device. In November
2012 a successful operation of the complete
system was demonstrated at ETH Zurich, see
Fig. 1.
The principal part of µSOFC, (as depicted in
Fig. 1 part (5) and in Fig. 2), includes electrodes
and electrolyte membranes. The challenging
contribution of our institute during 2012 was
to provide a validated guideline design for the
layered membranes system under both manufacturing and operational conditions. In our
planar design, thin film YSZ (yttria-stabilisedzirconia) electrolyte layers were fabricated using
pulsed laser deposition (PLD). The fabrication
is accompanied by large residual compressive
stresses that cause the electrolyte to buckle.
This buckling behaviour was investigated based
on various experimental methods, analytical estimations, and numerical simulations.
Fig. 1: Demonstration of µSOFC system. Lab on
chip: Bieberle-Hutter A. et al. (2012), 4894-4902
Fig. 2: µSOFC: membranes (left), carrier and electrical board (right) in the scale of portable device.
Experimentally, the films have been investigated
by wafer curvature, light microscopy, white light
interferometry and nano-indentation. The partial release of residual stresses in the film during free etching of the substrate was estimated
by a new method combining pre-etching optical measurements with posteriori stress analysis. An energy minimization procedure was
subsequently applied in combination with the
Rayleigh-Ritz method to determine the various
buckling modes, evaluate the buckling amplitudes and determine the threshold values for instability transitions. Comparisons between simulation results and experimental data show excellent agreement and demonstrate the capabilities of this method to predict various buckling
stages of free-standing thin films.
Finally, a new post-buckling design space for
thin-film electrolyte fabrication has been obtained by applying a stress-based failure criterion, see the following figure.
Fig. 3: The design space for the fabrication of thin
YSZ films is shown. The x-axis represents the side
length-to-thickness ratios whereas the y-axis represents the residual strain of the film. Under compression, i.e. for negative strains, pre-buckling only
exists in a narrow region above the curve of the first
buckling. The first and the second post-buckling regions located below the dashed curves c1 and c2
represent zones of high tensile stresses that have to
be avoided. However, the post-buckling region also
includes large safe zone located above c1 and c2.
Therefore, post-buckling design provides various options for a safe selection of deposition conditions and
membrane dimensions.
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2.7
Belenos Fuel Cell Stack: Simulation and Freezing
Contributors:
J. Schumacher, B. Perucco, G. Sartoris
Partners:
Funding:
Duration:
PSI, Belenos Clean Power
Swiss Federal Office of Energy, Belenos Clean Power
2010–2014
Introduction
Proton exchange membrane (PEM) fuel cells
generate electrical power from hydrogen gas
and currently undergo intensive research and
development. PEM fuel cells are applied for
transportation, back-up power, portable power
and small distributed generation.
Belenos Clean Power, in cooperation with the
Paul Scherrer Institute develops PEM fuel cell
systems for passenger vehicles. Certain research aspects become relevant for further development of these fuel cells. In this project
we develop coupled (or multiphysics) models to
represent the interaction between the transport
and reaction processes that are present in an
operating PEM fuel cell. Analyzing these interactions by combination of simulation and measurement is essential to identify the energy conversion losses and to improve the fuel cell performance. The Paul Scherrer Institute provides
the experimental background for model validation and calibration.
Modeling approaches
Transport processes of mass, charge and heat
on different length scales of the fuel cell components have to be analyzed to understand and
improve the performance of the fuel cell. In the
project we focus on two different approaches:
1. We develop a membrane electrode assembly (MEA) model that represents the electrochemical reactions and the transport processes
in the through-plane direction of a proton exchange membrane fuel cell. 2. We develop
a 2+1D model of a large-area PEM fuel cell.
The 2+1D approach captures the essential features of the coupled transport and reaction processes, and it is suitable to take the high aspect ratio between the in-plane and the throughplane dimensions of fuel cells into account. In
the 2+1D model the gas flow-fields of the PEM
fuel cell on the anode side and the cathode side
are numerically discretized in two dimensions
by using a finite element method. This allows
to calculate the pressure and velocity distributions in the gas flow-fields. The coupling between two opposing elements of the anode and
cathode side is established by the 1D model
(see above) representing the MEA. The transport processes for mass and charge and the
electrochemical reactions are accounted for in
the model by a nonlinear coupled system of partial differential equations.With the computationally efficient 2+1D model we intend to investigate different large-area fuel cell designs.
Sensitivity analysis
In 2012 we performed a sensitivity study of the
one-dimensional MEA model. Thereby, we identified the most important model parameters. The
investigated model parameters have different influence on the simulation results, i.e. the current
drawn from the cell, the average water content
or the maximum temperature to be reached in
the MEA. The influence of the parameters on
the simulation results depend on the operating
points on the current voltage curve of the cell.
To determine the sensitivity of a parameter on a
specific simulation result, a base case value for
all the parameters is defined resulting in a base
case simulation for the simulation like the current, for example. The investigated model parameters were varied within a certain range of
values. The simulation results with variable parameters were compared to the simulation results obtained for the base case to evaluate the
sensitivity.
Validation of the MEA model
Quantitative predictions with a fuel cell model
can only be achieved if the model is carefully
validated. In 2012 we focused on the validation of the electrochemical model description. A
small area test fuel cell was used to validated
the electrochemical part of the MEA model. The
cell voltage was measured as a function of the
molar fractions of oxygen and hydrogen, the
temperature and the current density.
Flow-field simulations in three dimensions
We performed an evaluation study to design different gas distribution flow-fields. A gas flowfield design with parallel channels was investigated and three-dimensional flow-field calculations were performed by solving the incompressible Navier-Stokes equations with a finite
element code. In this way we calculated the
pressure distribution and the velocity field in the
channels. The aim of the study was to achieve a
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homogeneous pressure drop over the gas distribution channels. Different gas inlets and outlet
designs were investigated and different gas mixture volume flows were used as boundary conditions at the inlet and outlet. Furthermore, consumption of the reactant gases in the gas distribution channels was modeled. Depending on
gas consumption, this requires the gas distribution channels to narrow towards the outlet of the
flow-field to achieve a minimum pressure drop.
This is essential to force the water out of the
channels. Some simulation results can be seen
in the figure, where the pressure distribution and
velocity field of an actual flow-field are plotted.
In the presented case, for example, it can be
seen from the pressure distribution plot that the
pressure distribution is not homogeneous over
a defined cross-section of the gas distribution
channels. These 3D gas flow simulations are
important to establish reference cases that can
be compared to the simplified 2+1D simulation
approach.
Simulated three dimensional pressure distribution (left) and velocity field (right) of a straight-channel gas flowfield of a PEM fuel cell. The incompressible Navier-Stokes equations were solved. Boundary conditions for
the flow-field at the inlet and the outlet were defined by known volume flow of the gas mixture. We assumed
depletion of the gas in the gas distribution channels.
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3.1
Exploring and Improving Durability of Thin Film Solar Cells
Contributors:
T. Lanz, M. Schmid, C. Kirsch, B. Ruhstaller
Partners:
FP-EMPA, TF-EMPA, LPI-EPFL, PV-Lab-EPFL, CSEM, SUPSI, BASF, AMCOR, Solaronix, Oerlikon Solar, Pramac, Flisom, Fluxim
Competence Center Energy and Mobility
2011–2013
Funding:
Duration:
The efficiency of thin film solar cells deteriorates
with time due to degradation phenomena. The
CCEM-CH project DURSOL aims at improving
the understanding of the fundamental mechanisms underlying the degradation. ICP’s task
within the project is to advance and extend the
numerical models of the various solar cell types
being investigated.
Fig. 1: Calculated steady-state heating distribution
in an amorphous silicon thin-film solar module in the
dark for Vapp = −4 V. An artificial shunt was added in
the module creating a short circuit between two back
contacts.
The performance of thin film solar modules
may deteriorate due to the degradation of the
electrical conductivity of transparent electrodes
caused by water ingress. As the water diffuses
into the module from the edges, a spatial representation of the module is required to assess
the influence on the module performance. To investigate the kinetics of water ingress and other
localized defects, we have developed a finite
element method (FEM) model of the electrothermal transport in thin film solar modules. The
model uses a computationally efficient 2+1D
modeling approach. Using amorphous silicon
mini solar modules we have experimentally validated the model using current-voltage measure-
ments under partial shading and lock-in thermography measurements. In Fig. 1 we show
the computed local heating rate in the mini module with artificially added shunts. The model
thus allows for a quantitative interpretation of
the temperature measurements obtained with
lock-in thermography. We will use the model to
study the performance degradation due to water
ingress based on measured diffusion patterns.
In close collaboration with the industrial partner
Fluxim AG transient electrical characterization
techniques for solar cells have been developed.
The measurement setup is capable of carrying
out dark-CELIV, photo-CELIV as well as lightpulse photocurrent responses. The measurements allow for extracting material parameters
such as the electron and hole charge mobilities. In Fig. 2 we show dark-CELIV measurements of CIGS solar cells from EMPA. From the
observed peak time we can estimate an effective mobility of 0.35 cm2 /Vs, which is in agreement with the expectations for this type of solar cell. We note that the experimental setup
is able to resolve the dynamic transport with
sub-microsecond resolution, as demonstrated
by this high-charge-mobility solar cell.
Fig. 2: Measurements of the transient current response to linearly increasing voltage (CELIV) ramps
for various offset voltages for CIGS solar cells.
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3.2
Simulation of Hydrogen Production with a Photoelectrochemical Solar Cell
Contributors:
P. Cendula, J. Schumacher, M. Schmid
Partners:
Funding:
Duration:
LPI-EPFL
Swiss Federal Office of Energy
2012–2014
Introduction
Electrical energy consumption peaks at day and
lowers at night. Solar energy production varies
between summer and winter and it depends on
clouds as well. Therefore, large effort on energy
storage solutions is undertaken to balance our
energy usage with renewable energy production. Hydrogen is one of the main candidates for
such energy storage solutions, because it is an
excellent and clean fuel. One obvious solution
to renewable hydrogen production is the electrolysis of water with input of renewable electric
energy. Another promising alternative to the latter is a photoelectrochemical (PEC) water splitting solar cell, which could be a cheaper single
device. A PEC cell absorbs light like a conventional solar cell, but the generated charges are
used to drive a water reduction and oxidation reaction in the aqueous electrolyte to produce hydrogen and oxygen, see Fig. 1.
Fig. 1: Photograph of a simple PEC cell for water
splitting. Courtesy of the Laboratory of Photonics
and Interfaces, EPFL Lausanne.
Motivation The current challenge is to find
cheap materials with excellent suitability for
PEC cells. Metal oxides such as hematite (iron
oxide) and copper oxide have shown certain
promise with respect to hydrogen production,
but they need to be understood and optimized
in order to become economically viable. Numerical simulation is crucial for improved understanding and predicting the behavior of PEC
cells and for the characterization of appropriate
materials for PEC cells.
Model In collaboration with LPI EPFL, ICP is developing a physical model of the light absorption, energy-band alignment and charge transport in the PEC cell. The optical model is based
on forward ray-tracing to simulate the fraction of
light that is absorbed, reflected or transmitted
through the PEC cell. The electrical model consists of electron and hole continuity equations
coupled with Poisson’s equation for the electric
potential. The electrical model is numerically
solved to calculate the current vs. voltage characteristics or impedance spectra of PEC cells.
Results In 2012, we implemented a software to
calculate an energy-band diagram of a PEC cell,
see Fig. 2. At this stage, the software plots the
energy-bands adopting the analytical solution of
the Poisson equation for electric potential. However, we also developed a numerical solution of
the Poisson equation, which will be used later in
the project. For example, one can deduce the
ability of hematite to oxidize water because its
quasi-Fermi energy of holes EF∗ p is below the
water oxidation potential Eox . By varying the
material parameters like bandgap energy, diffusion length of holes etc., their effect on the ability
to oxidize water can be understood. Since the
PEC cell community often refers to the energyband diagram only with qualitative argumentation, our energy-band diagram improves the understanding of PEC cells for various materials
and resolves some inconsistencies found in the
PEC literature.
For the optical model, optical reflections were
measured at EPFL for standalone Quartz and
Glass-FTO and also for a complete PEC cell
with hematite. Currently, we are collecting material data for the spectral refractive index and
the extinction coefficient of the individual layers,
which will enable analysis of optical losses in the
individual layers.
Outlook Currently, we are working on an extension of the electrical model to account for the
surface states in the semiconductor and a transient numerical model to simulate ac impedance
spectra. Furthermore, we are developing an optical model to simulate the reflection and the absorption of light. The simulation results are compared with measurements of PEC cells that are
performed at EPFL.
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Fig. 2: Snapshot of the energy-band diagram of a PEC cell with n-type hematite (implemented in Mathematica). Material parameters can be interactively changed to see their effect on the energy-band positions.
The common scale of electrochemical energy is used : the left axis shows an energy with respect to the
normal hydrogen electrode (NHE) and the right axis with respect to the reference hydrogen electrode (RHE).
Conduction and valence band edges of the semiconductor separated from electrolyte, ECB and EV B , are
shown as dashed lines. Upon contacting the semiconductor with electrolyte, a space charge region is formed
in the semiconductor which causes the bending of band edges (shown as solid lines). An applied bias potential Va further increases the band bending in the semiconductor and shifts the semiconductor Fermi level
EF n = EF p down. Upon illumination, the concentration of photogenerated holes dramatically increases as
reflected in their quasi-Fermi level EF∗ p . Electrochemical potentials for oxidation and reduction of water are
denoted Eox and Ered , respectively. The Fermi level in the metal EF,metal is automatically adjusted by potentiostat to enable hydrogen evolution at the metal (with certain overpotential above Ered ).
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3.3
Integration of High Temperature Electric Converter for Electricity Generation in a Solide Oxide Fuel System
Contributors:
M. Schmid
Partners:
Funding:
Duration:
SSC-EMPA, LPCM-EPFL, ITP-ETHZ, CRISMAT-CNRS (Fr), Hexis AG
Competence Center Energy and Mobility, Swiss Federal Office of Energy
2012–2016
Solide oxide fuel cells (SOFCs) convert chemical energy stored in a fuel (hydrogen or natural
gas) to electricity. The combustion of the fuel
in the SOFC leads to waste heat of temperatures up to 900 ◦ C. When the SOFC system is
integrated in buildings, the waste heat is usually
used for hot water production. However, using
thermoelectric converters (TECs) a part of the
waste heat may be converted to additional electricity, which is the most valuable form of energy.
The goal of this project is to develop a thermoelectric converter for the implementation into the
SOFC system of Hexis AG.
Thermoelectric converters consist of thermoelectric legs made of two different semiconductor materials (see Figure 2). The legs are connected electrically in series and thermally in parallel. If a temperature gradient is applied along
the legs an electrical potential difference between the hot and the cold side is formed. The
potential difference is due to the so called Seebeck effect. The potential difference leads to
an electrical current flowing through the thermoelectric legs. The working principle of a TEC
containing a single thermoelectric couple is illustrated in Figure 1.
Fig. 1: Working principle of a TEC built with two thermoelectric legs.
Low temperature TECs are already available on
the market. These TECs are attached to hot
parts of motors or stoves. However, for higher
temperatures above about 300 ◦ C the appropriate materials still have to be developed.
Fig. 2: Thermoelectric Converter. Image Courtesy:
EMPA
These materials not only have to resist the
higher temperatures, they also have to combine
some competing physical properties: high electrical conductivity and thermolectric effect, but at
the same time high thermal resistivity. Ideal candidate materials include perowskite-like metal
oxides. These candidate materials are developed and investigated at SSC-EMPA in order
to construct high temperature TECs to temperatures up to 900 ◦ C.
The work task of the ICP in this project is to develop a physical model for these high temperature TECs. The model is used to simulate temperature, electric potential, current and heat flow
density distribution inside the TECs. In Figure 3,
we show the electric potential distribution inside
the two TEC legs along the central line.
Fig. 3: Electric potential inside the TEC legs along
the central line (black and blue lines are for the ntype and p-type leg respectively). The temperature
dependence of the material properties is taken into
account.
The simulations allow to derive guidelines for
the optimal design of the TEC modules and to
quantify the different energy conversion losses.
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3.4
Thermofluiddynamische Modellierung von Biomassevergasung
Contributors:
G. Boiger, T. Hocker, C. Meier
Partners:
Funding:
Duration:
Keine
Gebert Rüf Stiftung
2009–2013
Die Vergasung von Biomasse wie zum Beispiel
Holz bietet die Möglichkeit, einen stückförmigen, festen Energieträger in eine Gasphase mit
hoher Energiedichte und Homogenität umzuwandeln. Dieses Konzept hat bedeutende technische Relevanz und gilt als Verfahren mit Potential.
Mit heutigem Stand der Technik fällt es nach
wie vor schwer grosse Biomassevergasungsanlagen mit ausreichender Rentabilität zu betreiben. Einer der Hauptgründe dafür ist die hohe
Wartungsintensität derartiger Aggregate. Dies
ist unter anderem darauf zurückzuführen, dass
kaum flexible und konsistente Konzepte zur dynamischen Anpassung der wichtigsten Anlageparameter an variierende Brennstoffqualitäten existieren. Zur effizienten Anlagenbetreuung benötigt der Betreiber eine Steuerung, oder
zumindest einen Leitfaden, welcher die wichtigsten Regelgrössen des Vergasungsprozesses (wie z.B.: Prozessluftzufuhr, Produktgasrückführung, Prozessluftvorwärmung) an die Eigenheiten des momentan zugeführten Rohstoffes (wie Porosität der Schüttung, Permeabilität,
Heizwert, Feuchtegehalt) anpasst. Thermofluiddynamische Modellierung des Vergasungsprozesses kann einen derartigen Zusammenhang
herstellen und somit dazu dienen Regeln für die
Steuerung von Anlagen beliebiger Größe abzuleiten.
Am ICP wird zunächst an einem möglichst kompakten, ein-dimensionalen, thermofluiddynamischen Modell des Vergasungsprozesses gearbeitet. Dieser Ansatz soll sich auf eine vereinfachende, aber grundlegende, analytische Aufarbeitung des gekoppelten Multiphysikproblems
des Vergasungsprozesses stützen. Dabei sollen
bereits viele, physikalisch relevante Teilbereiche
der Vergasung eines vereinfachten Biomassepartikels miteinbezogen werden. Es sind dies:
Die Zufuhr der Prozessluft in die Biomasseschüttung; Der Stofftransport des Sauerstoffes
an die Reaktionszone des einzelnen Biomassepartikels; Die Umwandlung der Prozessluft in
ein Gemisch aus Luft und Produktgas; Der konvektiv – diffusive Entropieaustausch zwischen
Partikel und Produktgas – Luft Gemisch; Die
thermisch getriebene Pyrolyse der Biomasse;
Die thermodynamisch und stöchiometrisch bestimmte, als Vergasung bezeichnete, Reaktion der Edukte zu Kohlenmonoxid, Wasserstoff,
Kohlendioxid, Methan, Wasserdampf und Sauerstoff, aber auch Kohle und teerigen Rückständen; Die Einstellung eines thermodynamischen
Gleichgewichtes des Produktgases in Abhängigkeit der vorherrschenden Temperatur; Die
Ermittlung der Energiebilanz sowie der Reaktionsenthalpie der Partikelmaterie, sowie die Weitergabe abströmender Materie und Entropie an
darauffolgende Partikelberechnungszellen.
Dieses ein-dimensionale Vergasungsmodell soll
möglichst modular aufgebaut sein, um durch
diverse Untermodelle (z.B. zur detaillierten
Beschreibung der Partikeltemperaturverteilung
bzw. dem Abdampfverhalten der Partikelfeuchtigkeit) ausgebaut werden zu können.
Das ein-dimensionale Schema soll also ein
theoretisches Fundament für die Ausweitung
der Betrachtung auf ein vollständiges, dreidimensionales Schüttgutmodell liefern. Ein, auf
der „open source CFD toolbox“, OpenFOAM
basierendes, vollständig drei-dimensionales,
thermofluiddynamisches Modell soll im weiteren Projektverlauf das ein-dimensionale Modell ablösen und ergänzen. Durch das Heranziehen detaillierter, la’grangscher Methodik zur
Beschreibung der drei-dimensionalen Schüttguteigenschaften soll es gelingen die Variationen zwischen verschiedenen Rohstoffqualitäten hochauflösend darzustellen. Damit bestünde die Möglichkeit, einen deutlichen Fortschritt
zu den bisherigen Möglichkeiten der Vergasungsmodellierung zu erzielen.
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4.1
Light Outcoupling from Organic Light-Emitting Diodes
Contributors:
C. Kirsch, R. Knaack, K. Lapagna, K. Pernstich, B. Ruhstaller
Partners:
Funding:
Duration:
Glas Trösch AG, Fluxim AG
CTI
2012–2014
Solid state lighting is an interesting field of application for organic light-emitting diodes (OLEDs),
in addition to their more prominent use in digital
displays of mobile phones or televisions. Largearea flat panel lights with homogeneous luminance can be produced using OLEDs. White
OLEDs are of particular interest in generalpurpose lighting applications, as they can produce warm white light that is more pleasing to
the human eye than the light from fluorescent
light sources. Because of the organic materials used, OLEDs are easier to dispose of than
fluorescent lamps, which contain phosphor and
mercury.
The luminous efficacy is an important quantity
for judging the energy efficiency of light sources:
it is the ratio between the total luminous flux
emitted by the device and the total amount of
input power it consumes. Current white OLED
devices have a luminous efficacy similar to fluorescent lamps and are catching up with (inorganic) LEDs.
The organic materials used in OLED devices
have a refractive index of n1 ' 1.7, and the
light emitted from the device needs to propagate into air with refractive index n2 ' 1 in a
typical lighting application. The contrast in refractive indices causes total internal reflection
of light beyond the critical incidence angle θc
(Fig. 1), which considerably reduces the luminous flux from an OLED device and thus its energy efficiency. Techniques for light outcoupling
improvement include scattering foils and other
high-index scattering layers.
In this project we are interested in the design
of light outcoupling layers which can be coated
on the large-area float glass produced by Glas
Trösch AG, and then be marketed to OLED
manufacturers. At another research institute,
techniques are developed to produce those layers, and both partners rely on the simulation results obtained by the ICP to assess the usefulness of various light outcoupling strategies.
Both geometrical optics and wave optics methods are applied in this project to simulate the
propagation of light from the OLED through the
light outcoupling layer and the glass substrate
into air: Mie scattering theory is used in a commercial raytracing software, and scalar scattering theory is used in the OLED and solar cell
simulation software Setfos by Fluxim AG. Here
we focus on wave optics.
Fig. 1: Total internal reflection for incidence angles
larger than the critical angle θc = arcsin(n2 /n1 ).
Our simulation approach is based on rigorous coupled wave analysis (RCWA). This is
a Fourier-space method for solving Maxwell’s
equations in the frequency domain, and it can
be used to simulate the propagation of light in
media with feature sizes on the order of the
wavelength of light. RCWA does not involve
any geometrical optics approximation and therefore diffraction and interference are naturally accounted for. Moreover, being a semi-analytical
method it can be much more computationally efficient than mesh-based methods.
The reflection and transmission properties of
light outcoupling layers for white OLEDs must
be non-dispersive, because otherwise the color
of the light emitted from the device would depend on the viewing angle. Simulations need to
be carried out over a range of wavelengths in order to verify this property for a given microstructure. With our RCWA simulation we were able to
shed light on the dispersion issue and we now
have a better idea of the kind of microstructures
that can be expected to be non-dispersive.
Simultaneously, prototype OLED devices are
produced and experimental investigations of
various light outcoupling strategies conducted
at ICP’s own optoelectronic research laboratory.
These experimental results are also used to validate the simulations.
30
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4.2
From Atoms to Large-Area OLEDs -the IM3OLED Project
Contributors:
E. Knapp, K. Lapagna, B. Ruhstaller
Partners:
Holst Centre (Nl), Philips (Nl), Fluxim AG, Moscow Engineering Physics Institute (Ru), Kintech Lab (Ru), Photochemistry Center of the Russian Academy
of Sciences (Ru)
EU-FP7
2011–2014
Funding:
Duration:
OLED technology provides an environmentally
friendly technology that requires no mercury
and can potentially enable energy savings up
to 90 % (per lamp socket). Global transition
to such efficient lighting sources would dramatically reduce the energy consumption. Since
the onset of the solid state lighting initiative towards the end of the last century, the advance
in OLED technology has been accelerated by a
world-wide investment in material science, process technology, and infrastructure. The technological hurdles are still challenging and numerous, and the target efficiency, colour, colour
rendering and lifetime has only partly been accomplished.
To tackle these issues the IM3OLED project (Integrated Multidisciplinary and Multiscale Modeling for Organic Light-Emitting Diodes) started in
2011. It is funded by the EU and is a collaboration between Russia and Europe. The overall goal of the IM3OLED project is the development, evaluation and validation of a predictive
multi-scale and multi-disciplinary modelling tool
that will accelerate research and development
of organic light-emitting diodes for lighting applications. In Fig. 1 shows the tool chain from
the molecular level up to the 3D OLED, where
simulations and experiments on different length
scales are performed. The focus of the ICP is
on the development and refinement of the continuum drift-diffusion model for organic semiconductors as well as on the electro-thermal largearea OLED model.
Fig. 1.: Simulation chain from the atom up to the 3D
device. The ICP develops electrical simulations as
well as 3D large-area OLEDs.
The ICP has developed an efficient large-area
OLED model based on a finite element approach. The results are shown in Fig. 2, where
the brightness of two OLEDs is compared. Due
to the low conductivity of the transparent anode,
a potential drop over the device takes place resulting in a reduced brightness as displayed on
the left. On the right, an improved OLED with a
metal grid structure to enhance the conductivity
of the anode is shown.
reference OLED
OLED with metal grid
Fig. 2.: Brightness distribution for a reference OLED
and an OLED with enhanced anode conductivity due
to a metal grid structure.
Further improvements can be achieved in the
light outcoupling of an OLED by introducing layers that contain microstructures such as scatter particles or micro lenses, which support the
extraction of waveguided and plasmonic modes
into the substrate and also contribute to the extraction from the substrate into air. These layers
can be partially modelled by means of geometrical optics. Therefore, the ICP has developed,
in close collaboration with Fluxim, a model that
combines the benefits of a semi-analytical description of dipole emission into such layers with
3D ray tracing capabilities.
31
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4.3
Erweiterung der Laborinfrastruktur zur Herstellung von Organischen Leuchtdioden am ICP
Contributors:
K. Pernstich, B. Ruhstaller, T. Beierlein
Partners:
Funding:
Duration:
keine
SoE-ZHAW
fortlaufend
Am ICP wird seit ca. 10 Jahren Forschung
auf dem Gebiet der organischen Elektronik auf
nationaler und internationaler Ebene betrieben,
bisher ausschliesslich mit Modellbildung, Simulation und Messtechnik. Das ICP hat dieses
Jahr seine Laborinfrastruktur um eine Beschichtungsanlage für kohlenstoffbasierte Halbleiter
erweitert. Diese Anlage bietet insbesondere die
Möglichkeit, organische Leuchtdioden (OLEDs),
aber auch organische Solarzellen und andere elektronische Bauteile auf Polymer-Basis
herzustellen.
Organische Leuchtdioden werden bereits in Displays kommerziell eingesetzt, z.B. im Smartphone Galaxy S3 von Samsung. Der Einsatz von OLEDs als grossflächige Beleuchtungselemente ist ebenfalls sehr vielversprechend. Solch grossflächige OLEDs benötigen keinen Lampenschirm wie konventionelle
Leuchtmittel, sie sind sozusagen der Lampenschirm. Dadurch eröffnen sich ganz neue
Einsatzmöglichkeiten, z.B. in der Architektur
als transparente OLEDs integriert in eine Fensterscheibe, als Hintergrundbeleuchtung für
Flüssigkristallanzeigen, oder als Stilelement in
Raumgestaltungen. OLEDs haben zudem im
Labormassstab bereits eine höhere Effizienz
als konventionelle Leuchtstofflampen bewiesen
und können so einen Beitrag zur Energieeffizienz liefern.
Die neu angeschaffte Beschichtungsanlage
besteht aus einer mit Stickstoff gefüllten Handschuhbox mit angeschlossener Vakuumkammer. In der Handschuhbox werden die Polymerfilme unter Ausschluss von Wasserdampf
und Sauerstoff hergestellt, und in der Vakuumkammer werden die benötigten Metallelektroden aufgedampft. Die elektrischen und optischen Eigenschaften der so hergestellten Proben
können nun messtechnisch untersucht werden
und dienen als Grundlage zur Verifikation und
Erweiterung von numerischen Modellen.
Die Möglichkeiten, die diese Beschichtungsanlage eröffnet, sind wichtig für Projekte mit Industriepartnern, in denen die durchgeführten Simulationen nun auch experimentell überprüft und
dadurch auch verfeinert werden können. Ein erstes KTI-Projekt, in dem die Anlage zum Einsatz
kam, ist auf Seite 30 beschrieben. Des weiteren
bietet die Anlage die Möglichkeit, zahlreiche
studentische Arbeiten durchzuführen. Diese
Arbeiten sind trotz ihres Praxisbezugs relativ
nahe an der Grundlagenforschung und daher
insbesondere für Studierende in Masterstudiengängen interessant.
Fotographie der neuen Beschichtungsanlage am ICP (links) und OLED Demonstrator der Firma Novaled
(rechts).
32
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Appendix
A.1
Student Projects
D. B ENZ , N. H ÄNI, ICE-LED Video Multi-Cluster mit Redundanz, Betreuer: N. Reinke, A. Bariska,
Bachelorarbeit.
B. B IGLER , F. M ATHYS, Early-stage skin cancer detection with active thermography, Betreuer:
M. Bonmarin, N. Reinke, A. Bariska, Bachelor Thesis.
B. B IGLER , F. M ATHYS, Measurement System for Early Stage Skin Cancer Detection, Betreuer:
N. Reinke, A. Bariska, Bachelorarbeit.
L. B RENNER , T. H UNKELER, Erstarrung von Schokolade im Kühlkanal, Betreuer: T. Hocker, O. Hoenecke, Firmenpartner: Max Felchlin AG, Schwyz, 2012, Projektarbeit Maschinentechnik, Bachelor
of Science.
P. FAHRNI , Y. W ERNER, Thermische Analyse von Schoggi im Kühlkanal, Betreuer: T. Hocker,
Firmenpartner: Max Felchlin AG, Schwyz, 2012, Bachelor Thesis Systemtechnik, Bachelor of Science.
D. G ÜRTLER, Nachhaltigkeit der Brennstoffzellentechnologie in der Mini-Kraft-Wärmekoppelung,
Betreuer: T. Hocker, H. Spiess, Firmenpartner: Hexis AG, Winterthur, 2012, Projektarbeit Maschinentechnik, Bachelor of Science.
L. K AUFMANN, Thermo-mechanisches Verhalten von Hochtemperatur-Brennstoffzellen, Betreuer:
T. Hocker, Firmenpartner: Hexis AG, Winterthur, 2012, Vertiefungsarbeit Master of Science.
P. L ENHERR , D. W ILD, Thermogradientenprüfstand für Brennstoffzellen, Betreuer: L. Kaufmann,
T. Hocker, Firmenpartner: Hexis AG, Winterthur, 2012, Bachelor Thesis Maschinentechnik, Bachelor of Science.
D. M INDER , S. O BRADOVIC, Erstarrung von Schokolade im Labor, Betreuer: T. Hocker, O. Hoenecke, Firmenpartner: Max Felchlin AG, Schwyz, 2012, Projektarbeit Maschinentechnik, Bachelor
of Science.
D. S CHMIDBAUER , M. TORRONI, Bilderkennung in Thermografie-Bildern, Betreuer: N. Reinke,
A. Bariska, Bachelorarbeit.
A. S IBILIA, Konstruktion und Herstellung eines Probenhalters für Vakuumbeschichtungen, Betreuer: K.P. Pernstich, B. Ruhstaller, Vertiefungsarbeit Master of Science.
M. S UTER, Modeling the Shukoff Cooling Curve of Oils, Betreuer: T. Hocker, Firmenpartner: Max
Felchlin AG, Schwyz, 2012, Vertiefungsarbeit Master of Science.
E. T INNER , R. A NGEHRN, Zerstörungsfreie und berührungslose Prüfung von Verbundmaterialien,
Betreuer: N. Reinke, A. Bariska, Bachelorarbeit.
33
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M. W ERNER , M. W YSS, Skin cancer detection with active thermography, Betreuer: M. Bonmarin,
N. Reinke, A. Bariska, Firmenpartner: Winterthur Instruments AG, Winterthur, Bachelor Thesis.
P. W ETTER , A. K ÜNZLER |, Bildgebendes Analyseverfahren für Feuchtigkeit in Bauwerken, Betreuer: N. Reinke, A. Bariska, Bachelorarbeit.
A.2
Scientific Publications
M. B ONMARIN , N. R EINKE , A. FASTRICH, Vorrichtung und Verfahren zur Charakterisierung von
Gewebe, Patent CH, Application Nr. 01684/12, Submitted.
D. B URNAT, A. H EEL , L. H OLZER , D. K ATA , J. L IS , T. G RAULE, Synthesis and Performance of
A-Site Deficient Lanthanum-Doped Strontium Titanate by Nanoparticle Based Spray Pyrolysis, J.
Power Sources, 201, 26–36, 2012.
D. B URNAT, A. H EEL , L. H OLZER , E.H. OTAL , D. K ATA , T. G RAULE, On the chemical interaction
of nanoscale lanthanum doped strontium titanates with common scandium and yttrium stabilized
electrolyte materials, Int. J. Hydrogen Energy, 37, 18326–18341, 2012.
A. E VANS , M. P RESTAT, R. TÖLKE , M. V. F. S CHLUPP, L. J. G AUCKLER , Y. S AFA , T. H OCKER ,
J. C OURBAT, D. B RIAND, N. F. DE R OOIJ, D. C OURTY, Residual Stress and Buckling Patterns of
Free-standing Yttria-stabilized-zirconia Membranes Fabricatedby Pulsed Laser Deposition, Fuel
Cells, 12, 614–623, 2012.
I. G RUBER , I. Z INOVIK , L. H OLZER , A. F LISCH , L. P OULIKAKOS, A computational study of the effect of structural anisotropy of porous asphalt on hydraulic conductivity, Construction and Building
Materials 96, 66–77, 2012.
B. I WANSCHITZ , L. H OLZER , A. M AI , M. S CHÜTZE, Nickel agglomeration in solid oxide fuel cells:
the influence of temperature, Solid State Ionics, 211, 69–73, 2012.
E. K NAPP, B. RUHSTALLER, The role of shallow traps in dynamic characterization of organic semiconductor devices , J. Appl. Phys. 112, 024519, 2012.
T. L ANZ , L. FANG , S.J. B AIK , K.S. L IM , B. RUHSTALLER, Photocurrent increase in amorphous
Si solar cells by increased reflectivity of LiF/Al electrodes, Solar Energy Materials and Solar Cells
107, 25, 2012.
C H . M EIER , T. H OCKER , A. B IEBERLE -H ÜTTER , L. J. G AUCKLER, Analyzing a micro-solid oxide
fuel cell system by global energy balances, Int. J. Hydrogen Energy, 37 (13), 10318–10327, 2012.
A. N AKAJO, J. K UEBLER , A. FAES , U. VOGT, H. S CHINDLER , L. C HIANG , S. M ODENA , J. VAN HER LE , T. H OCKER , Compilation of mechanical properties for the structural analysis of solid oxide fuel
cell stacks. Constitutive materials of anode-supported cells, Ceramics International, 38, 3907–
3927, 2012.
M.T. N EUKOM , S. Z ÜFLE , B. RUHSTALLER, Reliable extraction of organic solar cell parameters by
combining steady-state and transient techniques, Organic Electronics 13, 2012.
B. P ERUCCO, N.A. R EINKE , D. R EZZONICO, E. K NAPP, S. H ARKEMA , B. RUHSTALLER, On the
exciton profile in OLEDs-seamless optical and electrical modeling, Organic Electronics 13, 2012.
N. R EINKE, Pulverschichtdicken dank innovativer Autokalibration präzise messen, Besser lackieren, Juli 2012.
34
ZHAW
N. R EINKE, Feuchte Lacke auf Kunststoff messen, JOT Journal für Oberflächentechnik, Juni 2012.
J.O. S CHUMACHER , J. E LLER , G. S ARTORIS , B. S EYFANG , T. C OLINART, A 2+1D model of a
proton exchange membrane fuel cell with glassy-carbon micro-structures, Mathematical and Computer Modelling of Dynamical Systems, 1–23, 2012.
D. W IEDENMANN , L. K ELLER , L. H OLZER , J. S TOJADINOVIC, B. M ÜNCH , L. S UAREZ , B. F UMEY,
H. H AGENDORFER , R. B RÖNNIMANN , P. M ODREGGER , M. G ORBAR , U. VOGT, A. Z ÜTTEL , F. L A M ANTIA , R. W EPF, B. G ROBÉTY, 3D pore structure and ion conductivity of porous ceramic diaphragms, AIChE Journal, in press, 2012.
A.3
Book Chapters
L. H OLZER , M. C ANTONI, Nanofabrication using focused ion and electron beams: Principles and
applications, Book Chapter, Review of FIB-tomography / I. Utke, S.A. Moshkalev, Ph. Russell (Ed.)
- Oxford University Press, NY, USA, ISBN 9780199734214, 410–435, 2012.
A.4
News Articles
EMPA, Turbo für die Brennstoffzelle, Seite 27, c’t 2/2013.
N. W EIBEL, ZHAW entwickelt Computermodelle – lang lebe die Brennstoffzelle, Unternehmer
Zeitung.
A.5
Exhibitions
M. Bonmarin, Lock-In Thermography, World Medtech Forum, Lucerne, 2012.
M. Prestat et al. Miniaturized free-standing SOFC membranes on silicon chips. In: 10th EUROPEAN SOFC FORUM, Lucerne, 2012.
A.6
Conferences and Workshops
S. B AIK , M. N EUKOM , L. FANG , K. L IM , T. VAN DER H OFSTAD, T. L ANZ , B. RUHSTALLER, Fast and
direct characterization of thin film Si solar cells using CELIV, 27th European Photovoltaic Solar
Energy Conference and Exhibition, Frankfurt, Germany, 2012.
P. C ENDULA , M. S CHMID, J. O. S CHUMACHER, Development of a comprehensive numerical model
of a solar water splitting cell, International Conference on Nanostructured Systems for Solar Fuel
Production, Mallorca, Spain, 2012.
A. E VANS ET AL ., Residual stress and buckling patterns of yttria-stabilisedzirconia thin films for
micro-solid oxide fuel cell membranes, The Electrochemical Society, 221st ECS Meeting, Washington, USA, 2012.
L. H OLZER , M. C ANTONI , P H . G ASSER , B. M ÜNCH , L. K ELLER, FIB-tomography: Review and
discussion of applications in materials science, Interdisciplinary symposium on 3D-microscopy,
35
ZHAW
SSOM, Les Diablerets, 2012.
L. H OLZER , T H . H OCKER , L. K ELLER , M. P RESTAT ET AL ., Quantitative tomography for the prediction of transport kinetics in SOFC electrodes and in porous diaphragms for electroysis cells,
E-MRS Spring Meeting, Strasbourg, France, 2012.
B. I WANSCHITZ , L. H OLZER , A. M AI , M. S CHÜTZE, Nickel agglomeration in solid Oxide Fuel Cells
under different operating conditions, 10th European Fuel Cell Forum EFCF, A1001, Lucerne, 2012.
B. I WANSCHITZ , L. H OLZER , A. M AI , M. S CHÜTZE, Nickel agglomeration in solid Oxide Fuel
Cells under different operating conditions, Jahrestreffen Fachgruppen Energieverfahrenstechnik
und Hochtemperaturtechnik, DECHEMA, Frankfurt, Germany, 2012.
Y. J AMASHITA , B. RUHSTALLER, Advanced Characterization of Solar Cells, Swiss Green Technologies Seminar, Tokyo, Japan, 2012.
L. K ELLER , L. H OLZER, Imaging methods and its use in characterizing the pore space of Opalinus
Clay in 3D, Int. Clay Conference, Montpelier, France, 2012.
E. K NAPP, The Role of Shallow Traps in Dynamic Characterization of Organic Semiconductor Devices, SIMOEP 12, Olvia, Spain, 2012.
T. L ANZ , C. B ATTAGLIA , C. B ALLIF, B. RUHSTALLER, Model-based Quantitative Assessment of
Crystallinity and Parasitic Absorption in Microcrystalline Silicon Solar Cells, Spring MRS, San Francisco, USA, 2012.
M. N EUMANN , G. G AISELMANN , A. S PETTL , L. H OLZER , T. H OCKER , M. P RESTAT, V. S CHMIDT,
Structural Segmentation and Stochastic 3D modeling of La0.6Sr0.4CoO3-d - cathodes, 9th Symposium on Fuel Cell and Battery Modeling and Experimental Validation Modval, Sursee, 2012.
O. P ECHO, L. H OLZER , Z. YANG , T H . H OCKER , R. F LATT, J. M ARTINZUK , L. G AUCKLER , M. P RE STAT , Quantitative microstructure analysis and electrochemical activity of La0.6Sr0.4CoO3-d electrodes deposited by spray pyrolysis, Materials Research Fall Meeting MRS, Boston, USA, 2012.
O. P ECHO, M. P RESTAT, Z. YANG , J.H. H WANG , J.W. S ON , L. H OLZER , T. H OCKER , J. M AR TYNCZUK , L. G AUCKLER , Microstructural and electrochemical characterization of thin La0.6Sr0.4CoO3-d cathodes deposited by spray pyrolysis, 10th European Fuel Cell Forum EFCF, B04-61,
Lucerne, 2012.
O. P ECHO, M. P RESTAT, Z. YÁNG , L. H OLZER , T. H OCKER , J. M ARTYNCZUK , L. G AUCKLER,
Quantitative microstructure analysis and electrochemical activity of La0.6Sr0.4CoO3-d electrodes
deposited by spray pyrolysis, CFN Summer School on Nano-Energy, Poster, Bad Herrenalb, Germany, 2012.
M. P RESTAT, A. E VANS , R. TÖLKE , M.V.F. S CHLUPP, B. S CHERRER , Z. YANG , J. M ARTYNCZUK ,
O. P ECHO, H. M A , A. B IEBERLE -H UTTER , L. G AUCKLER , Y. S AFA , T. H OCKER , L. H OLZER ,
P. M URALT, Y. YAN , J. C OURBAT, D. B RIAND, N.F. DE R OOIJ, Miniaturized free-standing SOFC
membranes on silicon chips, 10th European Fuel Cell Forum EFCF, A07-30, Lucerne, 2012.
M. P RESTAT, L. H OLZER , T. H OCKER , O. P ECHO, ET AL ., Miniaturized solid oxide fuel cells on
a chip, 9th Symposium on Fuel Cell and Battery Modeling and Experimental Validation Modval,
Sursee, 2012.
M. P RESTAT, Z. YÁNG , O. P ECHO, L. H OLZER , J. M ARTYNCZUK , A. E VANS , L. G AUCKLER ,
T. H OCKER , J. H WANG , J. S ON, Nanostructured La0.6Sr0.4CoO3-d Cathodes Prepared by Spray
Pyrolysis for Thin Film SOFC, Pacific Rim Meeting on electrochem. and solid-state science / 222nd
36
ZHAW
meeting of ECS, PRIME2012, Honolulu, USA, 2012.
N. R EINKE, Thermische Schichtprüfung, Zentralschweizer Photonenmesstag - floir ag, GisikonRoot, 2012.
N. R EINKE, Berührungslose Prüfung von Materialien und Oberflächen, Thüringer Grenz- und
Oberflächentag, Leipzig, Germany, 2012.
N. R EINKE, Berührungslose Prüfung von Materialien und Oberflächen, Winterthurer Oberflächentag, Winterthur, 2012.
N. R EINKE, Feuchte Lacke auf Kunststoff messen, Fachtagung Oberflächentechnik, KunststoffInstitut Lüdenscheid, Germany, 2012.
N. R EINKE, Bildgebende Analyseverfahren für Mauerwerk, Tagung Einblick in Beton, Irscat AG,
Oberdorf, 2012.
B. RUHSTALLER, Advanced simulation of OLEDs and organic solar cells, Keynote Lecture at the
Winter School of Organic Electronics, Universität Heidelberg, Heidelberg, Germany, 2012.
B. RUHSTALLER, Charge Transport and Light Propagation in Organic Semiconductor Devices, Intl.
Conference on Simulation of Organic Electronics and Photovoltaics (SIMOEP), Oliva, Spain, 2012.
B. RUHSTALLER, Charge Transport and Light Propagation Modeling in Organic Semiconductor Devices, Jahrestagung der Schweizerischen Physikalischen Gesellschaft (SPG), Zürich, 2012.
Y. S AFA ET AL ., A Validated Model of Membrane Mechanics for Micro SOFC, 9th Symposium on
Fuel Cell and Battery Modelling and Experimental Validation, PSI Paul Scherrer Institut, 2012.
J.A. S CHULER , B. I WANSCHITZ , L. H OLZER , M. C ANTONI , T H . G RAULE, Stroboscopic Ni Growth/Volatilization Picture, 10th European Fuel Cell Forum EFCF, B0501, Lucerne, 2012.
J.O. S CHUMACHER , B. P ERUCCO, F ELIX N. B ÜCHI , J. R OTH, Sensitivity analysis and investigation of parameter interactions of a model of the membrane electrode assembly of a PEM fuel cell,
9th Symposium on Fuel Cell and Battery Modeling and Experimental Validation, Campus Sursee,
2012.
A.7
Prizes and Awards
E. Tinner and R. Angehrn received the Axa Innovationspreis for their Bachelor Thesis Zerstörungsfreie und berührungslose Prüfung von Verbundmaterialien.
N. Reinke and A. Bariska received the 2nd Rank Prix Strategis Award for their Spin-Off Company
Winterthur Instruments AG.
N. Reinke and A. Bariska received the 2nd Rank Swisspark Start-up of the year for their Spin-Off
Company Winterthur Instruments AG.
N. Reinke and A. Bariska received the besser lackieren! Produkthighlight Award for their Spin-Off
Company Winterthur Instruments AG.
N. Reinke and A. Bariska received the Heuberger Jungunternehmerpreis for their Spin-Off Company Winterthur Instruments AG.
37
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N. Reinke and A. Bariska received the Swiss Top 100 Entrepreneurs Award for their Spin-Off Company Winterthur Instruments AG.
P. Fahrni and Y. Werner received the 3. Price in Life Sciences of the Veronika und Hugo Bohny
Stiftung und Toolpoint Cluster for their Bachelor Thesis Thermische Analyse von Schoggi im Kühlkanal.
P. Wetter and A. Künzler received the Siemens Excellence Award for their Bachelor Thesis Bildgebendes Analyseverfahren für Feuchtigkeit in Bauwerken.
A.8
Teaching
M. B ONMARIN, Physik für Ingenieure 1, Bachelor of Science.
J.O. S CHUMACHER, Physik für Ingenieure 1, Bachelor of Science.
N. R EINKE, Physik für Ingenieure 1, Bachelor of Science.
N. R EINKE, Physik für Maschinentechnik 2, Bachelor of Science.
J.O. S CHUMACHER, Physik für Maschinentechnik 2, Bachelor of Science.
N. R EINKE, Physik für Systemtechnik 2, Bachelor of Science.
T. H OCKER, Physik und Systemwissenschaft für Aviatik 1, Bachelor of Science.
T. H OCKER, Fluid- und Thermodynamik 1, Bachelor of Science.
T. H OCKER, Fluid- und Thermodynamik 3, Bachelor of Science.
B. RUHSTALLER, Grundlagen der Solartechnik, Bachelor of Science.
B. RUHSTALLER, Messtechnik in Solarsystemen, Bachelor of Science.
T. H OCKER, Mensch–Technik–Umwelt, Bachelor of Science.
N. R EINKE, Sensorik Praktikum, Bachelor of Science.
R. A XTHELM, Mathematik für Ingenieure 1, Bachelor of Science.
R. A XTHELM, Mathematik für Ingenieure 2, Bachelor of Science.
R. A XTHELM, Mathematik: lineare Algebra für Ingenieure 1, Bachelor of Science.
M. S CHMID, Mathematik: lineare Algebra für Ingenieure 1, Bachelor of Science.
R. A XTHELM, Mathematik: lineare Algebra für Ingenieure 2, Bachelor of Science.
M. S CHMID, Mathematik: lineare Algebra für Ingenieure 2, Bachelor of Science.
C. K IRSCH, Natur, Technik und Systeme 1 – Praktikum, Bachelor of Science.
T. H OCKER, Heat and mass transfer with two-phase flow, Master of Science.
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J.O. S CHUMACHER, Advanced Thermodynamics, Master of Science in Engineering.
J.O. S CHUMACHER, Multiphysics Modelling and Simulation, Master of Science in Engineering.
J.O. S CHUMACHER, Mathematical Methods, Master Online Photovoltaics, Germany.
J.O. S CHUMACHER, Numerical Simulation of Solar Cells, Master Online Photovoltaics, Germany.
G. S ARTORIS, Masterprogram Micro- and Nanotechnology MNT, Weiterbildung.
39
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A.9
ICP-Team
Name
Function
e-Mail
Dr. Rebekka Axthelm
Dr. Gernot Boiger
Dr. Mathias Bonmarin
Dr. Peter Cendula
Samuel Hauri
Prof. Dr. Thomas Hocker
Dr. Lorenz Holzer
Lukas Kaufmann
Dr. Lukas Keller
Dr. Christoph Kirsch
Evelyne Knapp
Thomas Lanz
Kevin Lapagna
Markus Linder
Christoph Meier
Omar Pecho
Dr. Kurt Pernstich
Prof. Nils Reinke
Remo Ritzmann
Prof. Dr. Beat Ruhstaller
Dr. Yasser Safa
Dr. Guido Sartoris
Benjamin Schmid
Dr. Matthias Schmid
Prof. Dr. Jürgen Schumacher
Esther Spiess
Lilian Toniolo
Lecturer
Lecturer
Research Associate
Research Associate
Research Assistant
Lecturer, Head ICP
Research Associate
Research Assistant
Research Associate
Research Associate
Research Associate
Research Assistant
Research Assistant
Research Assistant
Research Assistant
Research Associate
Research Associate
Lecturer
Research Assistant
Lecturer
Research Associate
Research Associate
Research Assistant
Lecturer
Lecturer
Administrative Assistant
Administrative Assistant
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
40
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A.10
Spin-off Companies
www.nmtec.ch
Numerical Modelling GmbH works in the field of Computer Aided Engineering (CAE) and offers
services and simulation tools for small and medium enterprises. Our core competence is knowledge transfer: we bridge the gap between scientific know-how and its application in the industry.
With our knowledge from physics, chemistry and the engineering sciences we are able to profoundly support your product development cycle. Numerical Modelling speaks your language and
is able to conform to given constraints with respect to time and budget.
We often create so-called customer specific CAE tools in which the scientific knowledge required
for your product is embedded. In this form, it is easily deployed within your R&D department
and supports actual projects as well as improving the skills of your staff. Ask for our individual
consulting service which covers all areas of scientific knowledge transfer without obligation.
www.fluxim.com
FLUXiM AG is a provider of device simulation software to the display, lighting, photovoltaics and
electronics industries worldwide. Our principal activity is the development and the marketing of the
simulation software SETFOS which was designed to simulate light emission from thin film devices
such as organic light-emitting diodes (OLEDs), thin film solar cells (organic and inorganic) and
organic semiconducting multilayer systems.
Our company name FLUXiM is derived from flux simulation. Our software products are used
worldwide in industrial and academic research labs for the study of device physics and product
development. Check out our references and testimonials for more info. We develop swiss-made
software in Switzerland and in addition also provide services such as consulting, training and
software development, see our services page for more details.
www.winterthurinstruments.ch
Winterthur Instruments AG develops measurement systems for fast non contact and non destructive testing of industrial coatings. These measurement systems can be used to determine coating
thicknesses, material parameters (e.g. porosity) and contact quality (e.g. to detect delamination).
The system is based on optical-thermal measurements and works with all types of coating and
substrate materials. Our measurement systems provide the unique opportunity of non-contact and
non-destructive testing of arbitrary coatings on substrates.
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ZHAW
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Location
ICP Institute of
Computational Physics
Technikumstrasse 9
P.O. Box
CH-8401 Winterthur
www.icp.zhaw.ch
Contact
Thomas Hocker
Phone +41 58 934 78 37
[email protected]
Administration
Lilian Toniolo
Phone +41 58 934 73 06
[email protected]
TK-Building
TL-Building
Zurich University
of Applied Sciences
School of
Engineering
ICP Institute of
Computational Physics
Technikumstrasse 9
P.O. Box
CH-8401 Winterthur
Phone +41 58 934 71 71
[email protected]
www.icp.zhaw.ch

Research Report 2012

Transcription

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