Microkinetic Modeling of Nickel Oxidation in Solid Oxide Cells: Prediction of Safe Operating Conditions

2019 ◽  
Vol 91 (6) ◽  
pp. 843-855 ◽  
Author(s):  
Jonathan P. Neidhardt ◽  
Wolfgang G. Bessler
Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 36 ◽  
Author(s):  
Bruno Conti ◽  
Barbara Bosio ◽  
Stephen John McPhail ◽  
Francesca Santoni ◽  
Davide Pumiglia ◽  
...  

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


Author(s):  
Dieter Weichert ◽  
Abdelkader Hachemi

The special interest in lower bound shakedown analysis is that it provides, at least in principle, safe operating conditions for sensitive structures or structural elements under fluctuating thermo-mechanical loading as to be found in power- and process engineering. In this paper achievements obtained over the last years to introduce more sophisticated material models into the framework of shakedown analysis are developed. Also new algorithms will be presented that allow using the addressed numerical methods as post-processor for commercial finite element codes. Examples from practical engineering will illustrate the potential of the methodology.


2016 ◽  
Vol 29 (1) ◽  
pp. 1-10
Author(s):  
Hong Long ◽  
Mark Sweet ◽  
Sankara Narayanan

One of the critical requirements for high power devices is to have rugged and reliable capability against hash operating conditions. In this paper, we present the dynamic voltage clamping capability of 3.3kV Field Stop Clustered IGBT devices under extreme inductive load condition. It shows that PMOS trench gate CIGBT structure with outstanding performance of fast turn-off time and low over-shoot voltage. Further optimization of current gain of CIGBT structure is analyzed through numerical evaluation. A step further in the safe operating area has been achieved for high voltage devices by CIGBT technology.


2015 ◽  
Author(s):  
S. Seletskiy ◽  
C. Amundsen ◽  
K. Ha ◽  
A. Hussein

2011 ◽  
Vol 196 (4) ◽  
pp. 2080-2093 ◽  
Author(s):  
J. Laurencin ◽  
D. Kane ◽  
G. Delette ◽  
J. Deseure ◽  
F. Lefebvre-Joud

2019 ◽  
Vol 35 (1) ◽  
pp. 1571-1579 ◽  
Author(s):  
Virginie Roche ◽  
Claude Roux ◽  
Marlu Cesar Steil

Author(s):  
P. Kim-Lohsoontorn ◽  
H.-B. Yim ◽  
J.-M. Bae

The electrochemical performance of solid oxide electrolysis cells (SOECs) having nickel – yttria stabilized zirconia (Ni-YSZ) hydrogen electrode and a composite lanthanum strontium manganite – YSZ (La0.8Sr0.2MnO3−δ – YSZ) oxygen electrodes has been studied over a range of operating conditions temperature (700 to 900°C). Increasing temperature significantly increased electrochemical performance and hydrogen generation efficiency. Durability studies of the cell in electrolysis mode were made over 200 h periods (0.1 A/cm2, 800°C, and H2O/H2 = 70/30). The cell significantly degraded over the time (2.5 mV/h). Overpotentials of various SOEC electrodes were evaluated. Ni-YSZ as a hydrogen electrode exhibited higher activity in SOFC mode than SOEC mode while Ni/Ru-GDC presented symmetrical behavior between fuel cell and electrolysis mode and gave lower losses when compared to the Ni-YSZ electrode. All the oxygen electrodes gave higher activity for the cathodic reaction than the anodic reaction. Among the oxygen electrodes in this study, LSM-YSZ exhibited nearest to symmetrical behavior between cathodic and anodic reaction. Durability studies of the electrodes in electrolysis mode were made over 20–70 h periods. Performance degradations of the oxygen electrodes were observed (3.4, 12.6 and 17.6 mV/h for LSM-YSZ, LSCF and LSF, respectively). The Ni-YSZ hydrogen electrode exhibited rather stable performance while the performance of Ni/Ru-GDC decreased (3.4 mV/h) over the time. This was likely a result of the reduction of ceria component at high operating voltage.


Sign in / Sign up

Export Citation Format

Share Document