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Fichet V.,EIfER | Kanniche M.,Electricite de France | Plion P.,Electricite de France | Gicquel O.,Ecole Centrale Paris
Fuel | Year: 2010

The numerical prediction of NOx emissions from gas turbines is addressed in this paper. Generated from Computational Fluid Dynamics (CFD), a Reactor Network (RN) is defined to model the NOx formation with a detailed chemistry. An optimized procedure is proposed to split the reactive flow field into homogeneous zones considered as Perfectly Stirred Reactors (PSR). Once connected together, they result in a Chemical Reactor Network (CRN) that yields a detailed composition regarding species and temperature in the combustion chamber. Sensitivity studies are then performed to estimate the influence of air humidity and gas turbine load on NOx predictions. The NOx emissions predicted are in good agreement with the measured data in terms of levels and trends for the case studied (a gas turbine flame tube fed with natural gas and functioning at a pressure of 15 bar). Finally, the RN methodology has shown to be efficient estimating accurately NOx emissions with a short response time (few minutes) and small CPU requirements. © 2010 Elsevier Ltd. All rights reserved. Source


Grimaud A.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Mauvy F.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Bassat J.M.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Fourcade S.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | And 3 more authors.
Journal of the Electrochemical Society | Year: 2012

Four mixed ionic-electronic conducting (MIEC) perovskite-related oxides were studied as potential H +-SOFC cathode materials: La 0.6Sr 0.4Fe 0.8Co 0.2O 3-δ, Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3-δ, PrBaCo 2O 5 and Pr 2NiO 4+δ. Their hydration properties were measured by TGA: Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3-δ shows the largest water uptake. Their electrochemical performances were characterized using BaCe 0.9Y 0.1O 3-δ as electrolyte; polarization resistances as low as 0.5 cm 2 were found at 600C, for PrBaCo 2O 5 and Pr 2NiO 4+δ. The rate determining steps of the oxygen reduction reaction were determined on the basis of electrochemical studies performed as a function of pH 2O, in air. Proton transfer and water release appear to be the rate determining steps for Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3-δ, PrBaCo 2O 5 and Pr 2NiO 4+δ. No rate determining step involving proton was found for La 0.6Sr 0.4Fe 0.8Co 0.2O 3-δ. On the basis of this study, one can suggest that Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3-δ, PrBaCo 2O 5 and Pr 2NiO 4+δ show some protonic conduction as well as oxide diffusivity and can be labeled Triple Conducting (e-O 2-H +) Oxides, so-called TCO. © 2012 The Electrochemical Society. Source


Grimaud A.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Mauvy F.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Marc Bassat J.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | Fourcade S.,CNRS Laboratory of Condensed Matter Chemistry, Bordeaux | And 2 more authors.
Journal of Materials Chemistry | Year: 2012

The result of the substitution of Pr 3+ by Sr 2+ in the 214 Ruddlesden-Popper Pr 2NiO 4+δ material was studied with regard to its electrochemical properties as a H +-SOFC cathode. Structural characterizations as well as physical properties of the Pr 2-xSr xNiO 4+δ compounds (x ≤ 0.50), in particular hydration as a function of water partial pressure, have shown that oxygen over-stoichiometry and oxygen exchange with atmosphere decrease with increasing x, which has been correlated with the stabilization of the 214 structure by Sr 2+ substitution. Electrochemical studies on the oxygen reduction versus hydration have allowed determination of the rate determining steps of the formation of water and evidence the role of protons in Pr 2NiO 4+δ in contrast to Pr 2-xSr xNiO 4+δ oxides. It has been concluded that triple mixed conductivity (i.e. protonic, ionic as well as electronic conductivities) exists in this nickelate Pr 2NiO 4+δ. In addition, there was evidence for strong correlation between the insertion of protonic defects and additional oxygen in the interstitial position of Pr 2NiO 4+δ. © 2012 The Royal Society of Chemistry. Source


Nouvel R.,Stuttgart University of Applied Sciences | Bahu J.-M.,EIfER | Kaden R.,TU Munich | Kaempf J.,Ecole Polytechnique Federale de Lausanne | And 6 more authors.
14th International Conference of IBPSA - Building Simulation 2015, BS 2015, Conference Proceedings | Year: 2015

No widely applicable open information model standard exists until now for large-scale Urban Energy Modelling. Although different data models have been developed for different urban energy tools, they do not offer possibilities of interoperability and exchange between the stakeholders, tools and expert fields. To address this issue, an international group of urban energy simulation developers and users is developing since May 2014 an Application Domain Extension (ADE) Energy for the open urban information model CityGML. This paper introduces the Energy ADE developed and tested by this international urban energy group. Goals, requirements and the modular structure of the CityGML extension are described in detail. Source


Manceau J.C.,Bureau de Recherches Geologiques et Minieres | Tremosa J.,Bureau de Recherches Geologiques et Minieres | Audigane P.,Bureau de Recherches Geologiques et Minieres | Claret F.,Bureau de Recherches Geologiques et Minieres | And 7 more authors.
Energy Procedia | Year: 2014

In this study, we present a new experiment for following the evolution of the well integrity over time due to different changes in well conditions (pressure, temperature and fluids in contact with the well) in the context of CO2 geological storage. A small section of a wellbore is reproduced in the Opalinus Clay of the underground rock laboratory of Mont-Terri, Switzerland (caprock-like formation) at scale 1:1. This system has been characterized hydraulically and geochemically during three periods: Initial state, after an increase in the well temperature and after replacing the fluid by pore water with dissolved CO2. The characterization of the system includes both performing hydro-tests to quantify the hydraulic properties of the well and their evolution over time, and sampling the fluids to analyze the geochemical composition and changes. The results presented in this study confirm the ability of the chosen design to estimate the evolution of the well integrity over time. © 2014 The Authors. Published by Elsevier Ltd. Source

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