Documents disponibles écrits par cet auteur

CO2 capture from air via CaO-carbonation using a solar-driven fluidized bed reactor / V. Nikulshina in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 867-873 Titre : CO2 capture from air via CaO-carbonation using a solar-driven fluidized bed reactor : effect of temperature and water vapor concentration Type de document : texte imprimé Auteurs : V. Nikulshina, Auteur ; A. Steinfeld, Auteur Année de publication : 2010 Article en page(s) : pp. 867-873 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : CO2  captur  Air  Carbonation  Kinetics  Solar  energy  Radiation  Fluidized  bed  reactor Index. décimale : 660 Résumé : A two-step thermochemical cyclic process to capture CO2 from atmospheric air via consecutive CaO-carbonation CaCO3-calcination reactions is investigated using concentrated solar energy. A kinetic analysis of the carbonation of CaO with dry and moist air containing 500 ppm CO2 is performed in a fluidized bed solar reactor with particles directly exposed to high-flux thermal irradiation. The CO2 removal capacity was examined in the temperature range 290–390 °C and water vapor concentration range 0–17%. Complete CO2 removal was achieved from a continuous flow of moist air at 390 °C and residence times of less than 1.5 s, while the extent of CaO-carbonation was almost doubled by the addition of water vapor. Kinetic models that account for consecutive chemically and diffusion-controlled regimes were applied to describe the carbonation rate with dry air, limited initially through interface reactions and later through reactant penetration across the layer of CaCO3 until reaching the unreacted core. In contrast, a chemically-controlled rate law was applied to describe the augmented carbonation rate with moist air, which proceeded through the formation of an interface of water and/or OH ions at the solid surface not covered by CaCO3. The corresponding reaction orders and Arrhenius rate constants were determined by fitting to the experimental data. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XF840K-5&_user=6 [...] [article] CO2 capture from air via CaO-carbonation using a solar-driven fluidized bed reactor : effect of temperature and water vapor concentration [texte imprimé] / V. Nikulshina, Auteur ; A. Steinfeld, Auteur . - 2010 . - pp. 867-873. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 867-873 Mots-clés : CO2  captur  Air  Carbonation  Kinetics  Solar  energy  Radiation  Fluidized  bed  reactor Index. décimale : 660 Résumé : A two-step thermochemical cyclic process to capture CO2 from atmospheric air via consecutive CaO-carbonation CaCO3-calcination reactions is investigated using concentrated solar energy. A kinetic analysis of the carbonation of CaO with dry and moist air containing 500 ppm CO2 is performed in a fluidized bed solar reactor with particles directly exposed to high-flux thermal irradiation. The CO2 removal capacity was examined in the temperature range 290–390 °C and water vapor concentration range 0–17%. Complete CO2 removal was achieved from a continuous flow of moist air at 390 °C and residence times of less than 1.5 s, while the extent of CaO-carbonation was almost doubled by the addition of water vapor. Kinetic models that account for consecutive chemically and diffusion-controlled regimes were applied to describe the carbonation rate with dry air, limited initially through interface reactions and later through reactant penetration across the layer of CaCO3 until reaching the unreacted core. In contrast, a chemically-controlled rate law was applied to describe the augmented carbonation rate with moist air, which proceeded through the formation of an interface of water and/or OH ions at the solid surface not covered by CaCO3. The corresponding reaction orders and Arrhenius rate constants were determined by fitting to the experimental data. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XF840K-5&_user=6 [...]

Experimental and numerical analyses of a pressurized air receiver for solar-driven gas turbines / I. Hischier in Transactions of the ASME. Journal of solar energy engineering, Vol. 134 N° 2 (Mai 2012) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 134 N° 2 (Mai 2012) . - 08 p. Titre : Experimental and numerical analyses of a pressurized air receiver for solar-driven gas turbines Type de document : texte imprimé Auteurs : I. Hischier, Auteur ; P. Leumann, Auteur ; A. Steinfeld, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : solar energy Langues : Anglais (eng) Mots-clés : solar-driven  gas  turbines;  solar  radiation;  numerical  analysis Index. décimale : 621.47 Résumé : A high-temperature pressurized air-based receiver for power generation via solar-driven gas turbines is experimentally examined and numerically modeled. It consists of an annular reticulate porous ceramic (RPC) foam concentric with an inner cylindrical cavity-receiver exposed to concentrated solar radiation. Absorbed heat is transferred by combined conduction, radiation, and convection to the pressurized air flowing across the RPC. The governing steady-state mass, momentum, and energy conservation equations are formulated and solved numerically by coupled finite volume and Monte Carlo techniques. Validation is accomplished with experimental results using a 3 kW solar receiver prototype subjected to average solar radiative fluxes at the CPC outlet in the range 1870–4360 kW m−2. Experimentation was carried out with air and helium as working fluids, heated from ambient temperature up to 1335 K at an absolute operating pressure of 5 bars. The validated model is then applied to optimize the receiver design for maximum solar energy conversion efficiency and to analyze the thermal performance of 100 kW and 1 MW scaled-up versions of the solar receiver. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000002 [...] [article] Experimental and numerical analyses of a pressurized air receiver for solar-driven gas turbines [texte imprimé] / I. Hischier, Auteur ; P. Leumann, Auteur ; A. Steinfeld, Auteur . - 2012 . - 08 p. solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 134 N° 2 (Mai 2012) . - 08 p. Mots-clés : solar-driven  gas  turbines;  solar  radiation;  numerical  analysis Index. décimale : 621.47 Résumé : A high-temperature pressurized air-based receiver for power generation via solar-driven gas turbines is experimentally examined and numerically modeled. It consists of an annular reticulate porous ceramic (RPC) foam concentric with an inner cylindrical cavity-receiver exposed to concentrated solar radiation. Absorbed heat is transferred by combined conduction, radiation, and convection to the pressurized air flowing across the RPC. The governing steady-state mass, momentum, and energy conservation equations are formulated and solved numerically by coupled finite volume and Monte Carlo techniques. Validation is accomplished with experimental results using a 3 kW solar receiver prototype subjected to average solar radiative fluxes at the CPC outlet in the range 1870–4360 kW m−2. Experimentation was carried out with air and helium as working fluids, heated from ambient temperature up to 1335 K at an absolute operating pressure of 5 bars. The validated model is then applied to optimize the receiver design for maximum solar energy conversion efficiency and to analyze the thermal performance of 100 kW and 1 MW scaled-up versions of the solar receiver. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000002 [...]

Experimental and numerical determination of thermal radiative properties of ZnO particulate media / P. Coray in Journal of heat transfer, Vol. 132 N° 1 (Janvier 2010) 

Public ISBD [article]  in Journal of heat transfer > Vol. 132 N° 1 (Janvier 2010) . - pp. [012701-1/6] Titre : Experimental and numerical determination of thermal radiative properties of ZnO particulate media Type de document : texte imprimé Auteurs : P. Coray, Auteur ; W. Lipinski, Auteur ; A. Steinfeld, Auteur Article en page(s) : pp. [012701-1/6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Radiation  Radiometry  Radiative  spectroscopy  Monte  Carlo  Zinc  oxide  packed-bed Index. décimale : 536 Chaleur. Thermodynamique Résumé : The radiative characteristics of dependently scattering packed-beds of ZnO particles, applied in the design of high-temperature solar thermochemical reactors, were investigated experimentally. ZnO samples of varying thickness were exposed to a continuous beam of near monochromatic thermal radiation in the 0.5–1 µm wavelength range. The overall transmitted fraction measured as a function of sample thickness s obeys an exponential trend exp(−As), with the fit parameter A ranging from 4000±100 m−1 at 555 nm to 2100±100 m−1 at 1 µm. In the forward directions, the measured intensity distribution is approximately isotropic, whereas in the backward directions it is well approximated by a Henyey–Greenstein equation with asymmetry factors g[approximate]−0.4 at 555 nm and g[approximate]−0.1 at 1 µm. A Monte Carlo ray-tracing model of the experimental setup is employed to extract the extinction coefficient and the scattering albedo for the case of a nongray absorbing-scattering medium. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Experimental and numerical determination of thermal radiative properties of ZnO particulate media [texte imprimé] / P. Coray, Auteur ; W. Lipinski, Auteur ; A. Steinfeld, Auteur . - pp. [012701-1/6]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 132 N° 1 (Janvier 2010) . - pp. [012701-1/6] Mots-clés : Radiation  Radiometry  Radiative  spectroscopy  Monte  Carlo  Zinc  oxide  packed-bed Index. décimale : 536 Chaleur. Thermodynamique Résumé : The radiative characteristics of dependently scattering packed-beds of ZnO particles, applied in the design of high-temperature solar thermochemical reactors, were investigated experimentally. ZnO samples of varying thickness were exposed to a continuous beam of near monochromatic thermal radiation in the 0.5–1 µm wavelength range. The overall transmitted fraction measured as a function of sample thickness s obeys an exponential trend exp(−As), with the fit parameter A ranging from 4000±100 m−1 at 555 nm to 2100±100 m−1 at 1 µm. In the forward directions, the measured intensity distribution is approximately isotropic, whereas in the backward directions it is well approximated by a Henyey–Greenstein equation with asymmetry factors g[approximate]−0.4 at 555 nm and g[approximate]−0.1 at 1 µm. A Monte Carlo ray-tracing model of the experimental setup is employed to extract the extinction coefficient and the scattering albedo for the case of a nongray absorbing-scattering medium. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]

Experimental and numerical heat transfer analysis of an air-based cavity-receiver for solar trough concentrators / R. Bader in Transactions of the ASME. Journal of solar energy engineering, Vol. 134 N° 2 (Mai 2012) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 134 N° 2 (Mai 2012) . - 08 p. Titre : Experimental and numerical heat transfer analysis of an air-based cavity-receiver for solar trough concentrators Type de document : texte imprimé Auteurs : R. Bader, Auteur ; A. Pedretti, Auteur ; A. Steinfeld, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : solar energy Langues : Anglais (eng) Mots-clés : heat  transfer;  parabolic  trough;  simulation;  solar  receiver;  testing;  cavity;  air Index. décimale : 621.47 Résumé : We report on the field testing of a 42 m-long full-scale solar receiver prototype installed on a 9 m-aperture solar trough concentrator. The solar receiver consists of a cylindrical cavity containing a tubular absorber with air as the heat transfer fluid (HTF). Experimental results are used to validate a heat transfer model based on Monte Carlo ray-tracing and finite-volume techniques. Performance predictions obtained with the validated model yield the following results for the receiver. At summer solstice solar noon, with HTF inlet temperature of 120 °C and HTF outlet temperature in the range 250–450 °C, the receiver efficiency ranges from 45% to 29% for a solar power input of 280 kW. One third of the solar radiation incident on the receiver is lost by spillage at the aperture and reflection inside the cavity. Other heat losses are due to natural convection (9.9–9.7% of solar power input) and re-radiation (6.1–17.6%) through the cavity aperture and by natural convection from the cavity insulation (5.6–9.1%). The energy penalty associated with the HTF pumping work represents 0.6–24.4% of the power generated. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000002 [...] [article] Experimental and numerical heat transfer analysis of an air-based cavity-receiver for solar trough concentrators [texte imprimé] / R. Bader, Auteur ; A. Pedretti, Auteur ; A. Steinfeld, Auteur . - 2012 . - 08 p. solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 134 N° 2 (Mai 2012) . - 08 p. Mots-clés : heat  transfer;  parabolic  trough;  simulation;  solar  receiver;  testing;  cavity;  air Index. décimale : 621.47 Résumé : We report on the field testing of a 42 m-long full-scale solar receiver prototype installed on a 9 m-aperture solar trough concentrator. The solar receiver consists of a cylindrical cavity containing a tubular absorber with air as the heat transfer fluid (HTF). Experimental results are used to validate a heat transfer model based on Monte Carlo ray-tracing and finite-volume techniques. Performance predictions obtained with the validated model yield the following results for the receiver. At summer solstice solar noon, with HTF inlet temperature of 120 °C and HTF outlet temperature in the range 250–450 °C, the receiver efficiency ranges from 45% to 29% for a solar power input of 280 kW. One third of the solar radiation incident on the receiver is lost by spillage at the aperture and reflection inside the cavity. Other heat losses are due to natural convection (9.9–9.7% of solar power input) and re-radiation (6.1–17.6%) through the cavity aperture and by natural convection from the cavity insulation (5.6–9.1%). The energy penalty associated with the HTF pumping work represents 0.6–24.4% of the power generated. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000002 [...]

A modular ceramic cavity-receiver for high-temperature high-concentration solar applications / I. Hischier in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 1 (Fevrier 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 06 p. Titre : A modular ceramic cavity-receiver for high-temperature high-concentration solar applications Type de document : texte imprimé Auteurs : I. Hischier, Auteur ; P. Poživil, Auteur ; A. Steinfeld, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Coatings  Convection  Finite  element  analysis  Finite  volume  methods  Gas  turbines  Heat  conduction  Monte  Carlo  methods  Ray  tracing  Solar  power Index. décimale : 621.47 Résumé : A high-temperature pressurized air-based receiver is considered as a module for power generation via solar-driven gas turbines. A set of silicon carbide cavity-receivers attached to a compound parabolic concentrator (CPC) are tested on a solar tower at stagnation conditions for 35 kW solar radiative power input under mean solar concentration ratios of 2000 suns and nominal temperatures up to 1600 K. A heat transfer model coupling radiation, conduction, and convection is formulated by Monte Carlo ray-tracing, finite volume, and finite element techniques, and validated in terms of experimentally measured temperatures. The model is applied to elucidate the effect of material properties, geometry, and reflective coatings on the cavity's thermal and structural performances. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] A modular ceramic cavity-receiver for high-temperature high-concentration solar applications [texte imprimé] / I. Hischier, Auteur ; P. Poživil, Auteur ; A. Steinfeld, Auteur . - 2012 . - 06 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 06 p. Mots-clés : Coatings  Convection  Finite  element  analysis  Finite  volume  methods  Gas  turbines  Heat  conduction  Monte  Carlo  methods  Ray  tracing  Solar  power Index. décimale : 621.47 Résumé : A high-temperature pressurized air-based receiver is considered as a module for power generation via solar-driven gas turbines. A set of silicon carbide cavity-receivers attached to a compound parabolic concentrator (CPC) are tested on a solar tower at stagnation conditions for 35 kW solar radiative power input under mean solar concentration ratios of 2000 suns and nominal temperatures up to 1600 K. A heat transfer model coupling radiation, conduction, and convection is formulated by Monte Carlo ray-tracing, finite volume, and finite element techniques, and validated in terms of experimentally measured temperatures. The model is applied to elucidate the effect of material properties, geometry, and reflective coatings on the cavity's thermal and structural performances. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

A Solar trough concentrator for pill-box flux distribution over a CPV panel / R. Bader in Transactions of the ASME. Journal of solar energy engineering, Vol. 132 N° 1 (Janvier 2010) 

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