Dépouillements

Investigation of reverse thermosyphoning in an indirect SDHW system / Cynthia A. Cruickshank 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) . - 09 p. Titre : Investigation of reverse thermosyphoning in an indirect SDHW system Type de document : texte imprimé Auteurs : Cynthia A. Cruickshank, Auteur ; Stephen J. Harrison, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Heat  exchangers  Solar  absorber-convertors  Solar  heating  Thermal  energy  storage Index. décimale : 621.47 Résumé : Thermal energy storages with thermosyphon natural convection heat exchangers have been used in solar water heating systems as a means of increasing tank stratification and eliminating the need for a second circulation pump. However, if the storage system is not carefully designed, under adverse pressure conditions, reverse thermosyphoning can result in increased thermal losses from the storage and reduced thermal performance of the system. To investigate this phenomenon, tests were conducted on single tank and multitank thermal storages under controlled laboratory conditions. Energy storage rates and temperature profiles were experimentally measured during charge periods, and the effects of reverse thermosyphoning were quantified. Further objectives of this study were to empirically derive performance characteristics, to develop numerical models to predict the performance of the heat exchanger during reverse thermosyphon operation, and to quantify the relative magnitude of these effects on the energy stored during typical daylong charge periods. Results of this study show that the magnitude of the reverse flow rate depends on the pressure drop characteristics of the heat exchange loop, the system temperatures, and the geometry of the heat exchanger and storage tank. In addition, the results show that in the case of a multitank thermal storage, the carryover of energy to the downstream thermal energy storages depends on the effectiveness of the exchangers used in the system. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000001 [...] [article] Investigation of reverse thermosyphoning in an indirect SDHW system [texte imprimé] / Cynthia A. Cruickshank, Auteur ; Stephen J. Harrison, Auteur . - 2012 . - 09 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 09 p. Mots-clés : Heat  exchangers  Solar  absorber-convertors  Solar  heating  Thermal  energy  storage Index. décimale : 621.47 Résumé : Thermal energy storages with thermosyphon natural convection heat exchangers have been used in solar water heating systems as a means of increasing tank stratification and eliminating the need for a second circulation pump. However, if the storage system is not carefully designed, under adverse pressure conditions, reverse thermosyphoning can result in increased thermal losses from the storage and reduced thermal performance of the system. To investigate this phenomenon, tests were conducted on single tank and multitank thermal storages under controlled laboratory conditions. Energy storage rates and temperature profiles were experimentally measured during charge periods, and the effects of reverse thermosyphoning were quantified. Further objectives of this study were to empirically derive performance characteristics, to develop numerical models to predict the performance of the heat exchanger during reverse thermosyphon operation, and to quantify the relative magnitude of these effects on the energy stored during typical daylong charge periods. Results of this study show that the magnitude of the reverse flow rate depends on the pressure drop characteristics of the heat exchange loop, the system temperatures, and the geometry of the heat exchanger and storage tank. In addition, the results show that in the case of a multitank thermal storage, the carryover of energy to the downstream thermal energy storages depends on the effectiveness of the exchangers used in the system. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000001 [...]

Temperature fluctuation and evaporative loss rate in an algae biofilm photobioreactor / Thomas E. Murphy 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) . - 09 p. Titre : Temperature fluctuation and evaporative loss rate in an algae biofilm photobioreactor Type de document : texte imprimé Auteurs : Thomas E. Murphy, Auteur ; Halil Berberoglu, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Biofuel  Bioreactors  Microorganisms  Sensitivity  analysis  Solar  radiation Index. décimale : 621.47 Résumé : This study describes the thermal modeling of a novel algal biofilm photobioreactor aimed at cultivating algae for biofuel production. The thermal model is developed to assess the photobioreactor's thermal profile and evaporative water loss rate for a range of environmental parameters, including ambient air temperature, solar irradiation, relative humidity, and wind speed. First, a week-long simulation of the system has been performed using environmental data for Memphis, TN, on a typical week during the spring, summer, fall, and winter. Then, a sensitivity analysis was performed to assess the effect of each weather parameter on the temperature and evaporative loss rate of the photobioreactor. The range of the daily algae temperature variation was observed to be 12.2 °C, 13.2 °C, 11.7 °C, and 8.2 °C in the spring, summer, fall, and winter, respectively. Furthermore, without active cooling, the characteristic evaporative water loss from the system is approximately 6.0 L/m2 day, 7.3 L/m2 day, 3.4 L/m2 day, and 1.0 L/m2 day in the spring, summer, fall, and winter, respectively. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Temperature fluctuation and evaporative loss rate in an algae biofilm photobioreactor [texte imprimé] / Thomas E. Murphy, Auteur ; Halil Berberoglu, Auteur . - 2012 . - 09 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 09 p. Mots-clés : Biofuel  Bioreactors  Microorganisms  Sensitivity  analysis  Solar  radiation Index. décimale : 621.47 Résumé : This study describes the thermal modeling of a novel algal biofilm photobioreactor aimed at cultivating algae for biofuel production. The thermal model is developed to assess the photobioreactor's thermal profile and evaporative water loss rate for a range of environmental parameters, including ambient air temperature, solar irradiation, relative humidity, and wind speed. First, a week-long simulation of the system has been performed using environmental data for Memphis, TN, on a typical week during the spring, summer, fall, and winter. Then, a sensitivity analysis was performed to assess the effect of each weather parameter on the temperature and evaporative loss rate of the photobioreactor. The range of the daily algae temperature variation was observed to be 12.2 °C, 13.2 °C, 11.7 °C, and 8.2 °C in the spring, summer, fall, and winter, respectively. Furthermore, without active cooling, the characteristic evaporative water loss from the system is approximately 6.0 L/m2 day, 7.3 L/m2 day, 3.4 L/m2 day, and 1.0 L/m2 day in the spring, summer, fall, and winter, respectively. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

A numerical model for off-design performance prediction of parabolic trough based solar power plants / Giampaolo Manzolini 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) . - 10 p. Titre : A numerical model for off-design performance prediction of parabolic trough based solar power plants Type de document : texte imprimé Auteurs : Giampaolo Manzolini, Auteur ; Andrea Giostri, Auteur ; Claudio Saccilotto, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Heat  exchangers  Heat  transfer  Power  engineering  computing  Solar  absorber-convertors  Solar  power  stations  Steam  turbines Index. décimale : 621.47 Résumé : This paper deals with the development and testing of an innovative code for the performance prediction of solar trough based concentrated solar power (CSP) plants in off-design conditions. Off-design calculation starts from data obtained through the on-design algorithm and considers steady-state situations. The model is implemented in flexible software, named patto (parabolic trough thermodynamic optimization): the optical-thermal collector model can simulate different types of parabolic trough systems in commerce, including a combination of various mirrors, receivers and supports. The code is also flexible in terms of working fluid, temperature and pressure range, and can also simulate direct steam generation (DSG) plants. Solar plant heat and mass balances and performance at off-design conditions are estimated by accounting for the constraints imposed by the available heat transfer areas in heat exchangers, as well as by the characteristic curve of the steam turbine. The numerical model can be used either for single calculation in a specific off-design condition or for complete year simulation, by generating energy balances with an hourly resolution. The model is tested with a view to real applications and reference values found in literature: results show an overall yearly efficiency of 14.8% versus the 15% encountered in the Nevada Solar One. Moreover, the capacity factor is 25%, i.e., equal to the value predicted by sam®. Code potential in the design process reveals two different aspects: it can be used not only to optimize plant components and layout in feasibility studies but also to select the best control strategy during individual operating conditions. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] A numerical model for off-design performance prediction of parabolic trough based solar power plants [texte imprimé] / Giampaolo Manzolini, Auteur ; Andrea Giostri, Auteur ; Claudio Saccilotto, Auteur . - 2012 . - 10 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 10 p. Mots-clés : Heat  exchangers  Heat  transfer  Power  engineering  computing  Solar  absorber-convertors  Solar  power  stations  Steam  turbines Index. décimale : 621.47 Résumé : This paper deals with the development and testing of an innovative code for the performance prediction of solar trough based concentrated solar power (CSP) plants in off-design conditions. Off-design calculation starts from data obtained through the on-design algorithm and considers steady-state situations. The model is implemented in flexible software, named patto (parabolic trough thermodynamic optimization): the optical-thermal collector model can simulate different types of parabolic trough systems in commerce, including a combination of various mirrors, receivers and supports. The code is also flexible in terms of working fluid, temperature and pressure range, and can also simulate direct steam generation (DSG) plants. Solar plant heat and mass balances and performance at off-design conditions are estimated by accounting for the constraints imposed by the available heat transfer areas in heat exchangers, as well as by the characteristic curve of the steam turbine. The numerical model can be used either for single calculation in a specific off-design condition or for complete year simulation, by generating energy balances with an hourly resolution. The model is tested with a view to real applications and reference values found in literature: results show an overall yearly efficiency of 14.8% versus the 15% encountered in the Nevada Solar One. Moreover, the capacity factor is 25%, i.e., equal to the value predicted by sam®. Code potential in the design process reveals two different aspects: it can be used not only to optimize plant components and layout in feasibility studies but also to select the best control strategy during individual operating conditions. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

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 [...]

The effects of morphology on the oxidation of ceria by water and carbon dioxide / Luke J. Venstrom 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) . - 08 p. Titre : The effects of morphology on the oxidation of ceria by water and carbon dioxide Type de document : texte imprimé Auteurs : Luke J. Venstrom, Auteur ; Nicholas Petkovich, Auteur ; Stephen Rudisill, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Cerium  compounds  Hydrogen  production  Mesoporous  materials  Oxidation  Sintering Index. décimale : 621.47 Résumé : The oxidation of three-dimensionally ordered macroporous (3DOM) CeO2 (ceria) by H2O and CO2 at 1100 K is presented in comparison to the oxidation of nonordered mesoporous and sintered, low porosity ceria. 3DOM ceria, which features interconnected and ordered pores, increases the maximum H2 and CO production rates over the low porosity ceria by 125% and 260%, respectively, and increases the maximum H2 and CO production rates over the nonordered mesoporous cerium oxide by 75% and 175%, respectively. The increase in the kinetics of H2O and CO2 splitting with 3DOM ceria is attributed to its enhanced specific surface area and to its interconnected pore system that facilitates the transport of reacting species to and from oxidation sites. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] The effects of morphology on the oxidation of ceria by water and carbon dioxide [texte imprimé] / Luke J. Venstrom, Auteur ; Nicholas Petkovich, Auteur ; Stephen Rudisill, Auteur . - 2012 . - 08 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 08 p. Mots-clés : Cerium  compounds  Hydrogen  production  Mesoporous  materials  Oxidation  Sintering Index. décimale : 621.47 Résumé : The oxidation of three-dimensionally ordered macroporous (3DOM) CeO2 (ceria) by H2O and CO2 at 1100 K is presented in comparison to the oxidation of nonordered mesoporous and sintered, low porosity ceria. 3DOM ceria, which features interconnected and ordered pores, increases the maximum H2 and CO production rates over the low porosity ceria by 125% and 260%, respectively, and increases the maximum H2 and CO production rates over the nonordered mesoporous cerium oxide by 75% and 175%, respectively. The increase in the kinetics of H2O and CO2 splitting with 3DOM ceria is attributed to its enhanced specific surface area and to its interconnected pore system that facilitates the transport of reacting species to and from oxidation sites. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

An immersed boundary method for simulation of wind flow over complex terrain / S. Jafari 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) . - 12 p. Titre : An immersed boundary method for simulation of wind flow over complex terrain Type de document : texte imprimé Auteurs : S. Jafari, Auteur ; N. Chokani, Auteur ; R. S. Abhari, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Flow  Navier-Stokes  equations  Power  grids  Surface  roughness  Turbulence  Wind  turbines Index. décimale : 621.47 Résumé : The accurate modeling of the wind resource over complex terrain is required to optimize the micrositing of wind turbines. In this paper, an immersed boundary method that is used in connection with the Reynolds-averaged Navier–Stokes equations with k-omega turbulence model in order to efficiently simulate the wind flow over complex terrain is presented. With the immersed boundary method, only one Cartesian grid is required to simulate the wind flow for all wind directions, with only the rotation of the digital elevation map. Thus, the lengthy procedure of generating multiple grids for conventional rectangular domain is avoided. Wall functions are employed with the immersed boundary method in order to relax the stringent near-wall grid resolution requirements as well as to allow the effects of surface roughness to be accounted for. The immersed boundary method is applied to the complex terrain test case of Bolund Hill. The simulation results of wind speed and turbulent kinetic energy show good agreement with experiments for heights greater than 5 m above ground level. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] An immersed boundary method for simulation of wind flow over complex terrain [texte imprimé] / S. Jafari, Auteur ; N. Chokani, Auteur ; R. S. Abhari, Auteur . - 2012 . - 12 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 12 p. Mots-clés : Flow  Navier-Stokes  equations  Power  grids  Surface  roughness  Turbulence  Wind  turbines Index. décimale : 621.47 Résumé : The accurate modeling of the wind resource over complex terrain is required to optimize the micrositing of wind turbines. In this paper, an immersed boundary method that is used in connection with the Reynolds-averaged Navier–Stokes equations with k-omega turbulence model in order to efficiently simulate the wind flow over complex terrain is presented. With the immersed boundary method, only one Cartesian grid is required to simulate the wind flow for all wind directions, with only the rotation of the digital elevation map. Thus, the lengthy procedure of generating multiple grids for conventional rectangular domain is avoided. Wall functions are employed with the immersed boundary method in order to relax the stringent near-wall grid resolution requirements as well as to allow the effects of surface roughness to be accounted for. The immersed boundary method is applied to the complex terrain test case of Bolund Hill. The simulation results of wind speed and turbulent kinetic energy show good agreement with experiments for heights greater than 5 m above ground level. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Synchronization of a single-phase photovoltaic generator with the low-voltage utility grid / Nader Anani 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) . - 08 p. Titre : Synchronization of a single-phase photovoltaic generator with the low-voltage utility grid Type de document : texte imprimé Auteurs : Nader Anani, Auteur ; Omar Al-Kharji, Auteur ; Prasad Ponnapalli, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Digital  phase  locked  loops  Field  programmable  gate  arrays  Invertors  Photovoltaic  power  systems  Synchronisation Index. décimale : 621.47 Résumé : The increased generation of electrical energy from renewable sources and its integration into the low voltage grid have necessitated regulations governing the connection of renewable energy generators to the grid. This was deemed necessary to preserve the integrity and the correct operation of the grid. This paper presents a new architecture of a hybrid phase lock loop circuit topology for synchronizing a single-phase inverter fed from a renewable energy source such as a photovoltaic (PV) generator to the low voltage grid. The system uses a digital phase lock loop (DPLL) architecture, which is based on the arctan phase detector, driving a phase lock loop (PLL) to synchronize a PV inverter with the grid. The proposed system has been tested by simulation using simulink/matlab. The test results demonstrate the ability of the system to synchronize a PV inverter with the grid and to re-establish synchronization following a sudden perturbation in the grid voltage such as a single or a multistep change in phase. The system is digital and can be readily implemented using an FPGA (field programmable gate array) and hence can be easily embedded in a home or small scale single-phase PV inverter. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Synchronization of a single-phase photovoltaic generator with the low-voltage utility grid [texte imprimé] / Nader Anani, Auteur ; Omar Al-Kharji, Auteur ; Prasad Ponnapalli, Auteur . - 2012 . - 08 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 08 p. Mots-clés : Digital  phase  locked  loops  Field  programmable  gate  arrays  Invertors  Photovoltaic  power  systems  Synchronisation Index. décimale : 621.47 Résumé : The increased generation of electrical energy from renewable sources and its integration into the low voltage grid have necessitated regulations governing the connection of renewable energy generators to the grid. This was deemed necessary to preserve the integrity and the correct operation of the grid. This paper presents a new architecture of a hybrid phase lock loop circuit topology for synchronizing a single-phase inverter fed from a renewable energy source such as a photovoltaic (PV) generator to the low voltage grid. The system uses a digital phase lock loop (DPLL) architecture, which is based on the arctan phase detector, driving a phase lock loop (PLL) to synchronize a PV inverter with the grid. The proposed system has been tested by simulation using simulink/matlab. The test results demonstrate the ability of the system to synchronize a PV inverter with the grid and to re-establish synchronization following a sudden perturbation in the grid voltage such as a single or a multistep change in phase. The system is digital and can be readily implemented using an FPGA (field programmable gate array) and hence can be easily embedded in a home or small scale single-phase PV inverter. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Disinfection of natural water by solar photocatalysis using immobilized TiO2 devices / Asunción Acevedo 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) . - 10 p. Titre : Disinfection of natural water by solar photocatalysis using immobilized TiO2 devices : efficiency in eliminating indicator bacteria and operating life of the system Type de document : texte imprimé Auteurs : Asunción Acevedo, Auteur ; Edward A. Carpio, Auteur ; Juan Rodriguez, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Catalysis  Microorganisms  Photochemistry  Sol-gel  processing  Titanium  compounds  Water  treatment Index. décimale : 621.47 Résumé : Natural water has been disinfected using TiO2 as the fixed catalyst incorporated in a homemade photoreactor, in which the dimensions and the design parameters are representative of devices that are currently employed at larger scale. The catalyst was immobilized on the external surface of a cylinder of frosted glass situated in the longitudinal axis of a tubular glass reactor. Two alternative methods of immobilizing the catalyst on glass were studied: in the first, a commercial titanium oxide powder (Aeroxide® TiO2 P25) was mounted on a polymeric support; and in the second, it was applied by sol-gel deposition. Illumination was effected by installing the glass reactor in the irradiation chamber of a solar simulator. Under laboratory conditions, groundwater contaminated with cultured and wild bacteria was treated photocatalytically, and the influence of the photolysis, the pumping, and the catalysts was studied. The results obtained have demonstrated that the catalyst immobilized in the interior of the photoreactor presents similar results, in the disinfection of E. coli, as 0.5 g/l of TiO2 P25; and that, in 1.5 h approximately of simulated solar illumination (167 kWUVA s/m2) on the sol-gel deposit of TiO2, it is possible to eliminate 100% of the bacteria covered by international regulations in respect of water for human consumption. With regard to the aging assay of the system, it was observed at 250 h of operation a reduction in the effectiveness of the disinfection process. At 0 and 250 h of operation, the percentages of elimination of E. coli after 50 min of illumination were 100% and 99.5%, respectively. This reduction in the effectiveness of the process was due to the formation of a film of calcium carbonate adhering to the internal glass wall of the photoreactor, which is in contact with the liquid being treated, and to the presence of calcium carbonate precipitates on catalyst surface. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Disinfection of natural water by solar photocatalysis using immobilized TiO2 devices : efficiency in eliminating indicator bacteria and operating life of the system [texte imprimé] / Asunción Acevedo, Auteur ; Edward A. Carpio, Auteur ; Juan Rodriguez, Auteur . - 2012 . - 10 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 10 p. Mots-clés : Catalysis  Microorganisms  Photochemistry  Sol-gel  processing  Titanium  compounds  Water  treatment Index. décimale : 621.47 Résumé : Natural water has been disinfected using TiO2 as the fixed catalyst incorporated in a homemade photoreactor, in which the dimensions and the design parameters are representative of devices that are currently employed at larger scale. The catalyst was immobilized on the external surface of a cylinder of frosted glass situated in the longitudinal axis of a tubular glass reactor. Two alternative methods of immobilizing the catalyst on glass were studied: in the first, a commercial titanium oxide powder (Aeroxide® TiO2 P25) was mounted on a polymeric support; and in the second, it was applied by sol-gel deposition. Illumination was effected by installing the glass reactor in the irradiation chamber of a solar simulator. Under laboratory conditions, groundwater contaminated with cultured and wild bacteria was treated photocatalytically, and the influence of the photolysis, the pumping, and the catalysts was studied. The results obtained have demonstrated that the catalyst immobilized in the interior of the photoreactor presents similar results, in the disinfection of E. coli, as 0.5 g/l of TiO2 P25; and that, in 1.5 h approximately of simulated solar illumination (167 kWUVA s/m2) on the sol-gel deposit of TiO2, it is possible to eliminate 100% of the bacteria covered by international regulations in respect of water for human consumption. With regard to the aging assay of the system, it was observed at 250 h of operation a reduction in the effectiveness of the disinfection process. At 0 and 250 h of operation, the percentages of elimination of E. coli after 50 min of illumination were 100% and 99.5%, respectively. This reduction in the effectiveness of the process was due to the formation of a film of calcium carbonate adhering to the internal glass wall of the photoreactor, which is in contact with the liquid being treated, and to the presence of calcium carbonate precipitates on catalyst surface. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Development of a thermal model for photovoltaic modules and analysis of NOCT guidelines / Ty W. Neises 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) . - 07 p. Titre : Development of a thermal model for photovoltaic modules and analysis of NOCT guidelines Type de document : texte imprimé Auteurs : Ty W. Neises, Auteur ; Sanford A. Klein, Auteur ; Douglas T. Reindl, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : IEC  standards  Laminar  flow  Photovoltaic  cells  Solar  cell  arrays Index. décimale : 621.47 Résumé : The temperature of a photovoltaic module is typically required as an input to models that predict the module's performance. Some common models use the nominal operating cell temperature (NOCT), as by the manufacturer. This paper develops a thermal model and uses it to analyze NOCT testing standards. Specifically, the standard correction factor charts found in the ASTM E1036 and IEC 61215 standards are evaluated. Results show that the correction charts were likely created assuming laminar flow correlations, while validation efforts and the fact that wind is often characterized by turbulence even at low wind speeds suggest that turbulent flow models may be more appropriate. In addition, the results presented in this paper show that the standard NOCT charts do not account for the backside insulation of photovoltaic (PV) arrays. These results suggest that the standard correction charts are inaccurate for any mounting types that differ from the open rack configuration. The paper concludes with recommendations to improve the usefulness of the NOCT. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Development of a thermal model for photovoltaic modules and analysis of NOCT guidelines [texte imprimé] / Ty W. Neises, Auteur ; Sanford A. Klein, Auteur ; Douglas T. Reindl, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 07 p. Mots-clés : IEC  standards  Laminar  flow  Photovoltaic  cells  Solar  cell  arrays Index. décimale : 621.47 Résumé : The temperature of a photovoltaic module is typically required as an input to models that predict the module's performance. Some common models use the nominal operating cell temperature (NOCT), as by the manufacturer. This paper develops a thermal model and uses it to analyze NOCT testing standards. Specifically, the standard correction factor charts found in the ASTM E1036 and IEC 61215 standards are evaluated. Results show that the correction charts were likely created assuming laminar flow correlations, while validation efforts and the fact that wind is often characterized by turbulence even at low wind speeds suggest that turbulent flow models may be more appropriate. In addition, the results presented in this paper show that the standard NOCT charts do not account for the backside insulation of photovoltaic (PV) arrays. These results suggest that the standard correction charts are inaccurate for any mounting types that differ from the open rack configuration. The paper concludes with recommendations to improve the usefulness of the NOCT. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Use of a shroud and baffle to improve natural convection to immersed heat exchangers / Sandra K. S. Boetcher 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) . - 07 p. Titre : Use of a shroud and baffle to improve natural convection to immersed heat exchangers Type de document : texte imprimé Auteurs : Sandra K. S. Boetcher, Auteur ; F. A. Kulacki, Auteur ; Jane H. Davidson, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Heat  exchangers  Natural  convection  Numerical  analysis  Solar  power  Tanks  (containers)  Thermal  energy  storage  Transient  analysis  Water  storage Index. décimale : 621.47 Résumé : Optimizing heat transfer during the charge and discharge of thermal stores is crucial for high performance of solar thermal systems for domestic and commercial applications. This study models a sensible water storage tank for which discharge is accomplished using a heat exchanger immersed in the storage fluid. The heat exchanger is a two-dimensional isothermal cylinder in an adiabatic enclosure with no initial stratification. An adiabatic shroud and baffle whose geometry is parametrically varied is placed around and below the cylinder. Transient numerical simulations of the discharge process are obtained for 105 < RaD < 107, and estimates of the time needed to discharge a given fraction of the initial stored energy are obtained. We find that a short baffle is least effective in increasing heat transfer rates. The performance benefit is greatest early in the transient discharge period when the buoyant flow in the store is strongest. As with all flow control devices, the benefit decreases as energy is extracted from the tank and the temperature difference driving the flow decreases. The use of a shroud increases the transient Nusselt number by as much as twentyfold. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Use of a shroud and baffle to improve natural convection to immersed heat exchangers [texte imprimé] / Sandra K. S. Boetcher, Auteur ; F. A. Kulacki, Auteur ; Jane H. Davidson, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 07 p. Mots-clés : Heat  exchangers  Natural  convection  Numerical  analysis  Solar  power  Tanks  (containers)  Thermal  energy  storage  Transient  analysis  Water  storage Index. décimale : 621.47 Résumé : Optimizing heat transfer during the charge and discharge of thermal stores is crucial for high performance of solar thermal systems for domestic and commercial applications. This study models a sensible water storage tank for which discharge is accomplished using a heat exchanger immersed in the storage fluid. The heat exchanger is a two-dimensional isothermal cylinder in an adiabatic enclosure with no initial stratification. An adiabatic shroud and baffle whose geometry is parametrically varied is placed around and below the cylinder. Transient numerical simulations of the discharge process are obtained for 105 < RaD < 107, and estimates of the time needed to discharge a given fraction of the initial stored energy are obtained. We find that a short baffle is least effective in increasing heat transfer rates. The performance benefit is greatest early in the transient discharge period when the buoyant flow in the store is strongest. As with all flow control devices, the benefit decreases as energy is extracted from the tank and the temperature difference driving the flow decreases. The use of a shroud increases the transient Nusselt number by as much as twentyfold. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Temperature and irradiance dependence of a dye sensitized solar cell with acetonitrile based electrolyte / Edwin Peng 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) . - 07 p. Titre : Temperature and irradiance dependence of a dye sensitized solar cell with acetonitrile based electrolyte Type de document : texte imprimé Auteurs : Edwin Peng, Auteur ; Halil Berberoglu, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Dyes  Electrolytes  Solar  cells Index. décimale : 621.47 Résumé : Performance characteristics of an acetonitrile electrolyte based dye-sensitized solar cell were measured experimentally as functions of temperature (from 5 to 50 °C) and irradiance (from 500 to 1500 W m−2). The results indicated two thermal regimes of operation characterized by diffusion and recombination limitation. It was shown that in the diffusion dominated regime the photoconversion efficiency was not a strong function of temperature whereas it decreased significantly with increasing temperature in the recombination dominated regime. Also, it was shown that the recombination rate was not affected significantly by increase in irradiance resulting in an overall larger temperature dependence of cell performance at larger irradiances. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Temperature and irradiance dependence of a dye sensitized solar cell with acetonitrile based electrolyte [texte imprimé] / Edwin Peng, Auteur ; Halil Berberoglu, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 07 p. Mots-clés : Dyes  Electrolytes  Solar  cells Index. décimale : 621.47 Résumé : Performance characteristics of an acetonitrile electrolyte based dye-sensitized solar cell were measured experimentally as functions of temperature (from 5 to 50 °C) and irradiance (from 500 to 1500 W m−2). The results indicated two thermal regimes of operation characterized by diffusion and recombination limitation. It was shown that in the diffusion dominated regime the photoconversion efficiency was not a strong function of temperature whereas it decreased significantly with increasing temperature in the recombination dominated regime. Also, it was shown that the recombination rate was not affected significantly by increase in irradiance resulting in an overall larger temperature dependence of cell performance at larger irradiances. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Generation of a parabolic trough collector efficiency curve from separate measurements of outdoor optical efficiency and indoor receiver heat loss / Charles Kutscher 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 : Generation of a parabolic trough collector efficiency curve from separate measurements of outdoor optical efficiency and indoor receiver heat loss Type de document : texte imprimé Auteurs : Charles Kutscher, Auteur ; Frank Burkholder, Auteur ; J. Kathleen Stynes, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Heat  losses  Solar  absorber-convertors  Sunlight Index. décimale : 621.47 Résumé : The thermal efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The thermal efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain the thermal efficiency curve. This paper describes this approach and also makes the case that there are advantages to plotting collector efficiency versus the difference between the operating temperature and the ambient temperature at which the receiver heat loss was measured divided by radiation to a fractional power (on the order of 1/3 but obtained via data regression)—as opposed to the difference between operating and ambient temperatures divided by the radiation. The results are shown to be robust over wide ranges of ambient temperature, sky temperature, and wind speed. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Generation of a parabolic trough collector efficiency curve from separate measurements of outdoor optical efficiency and indoor receiver heat loss [texte imprimé] / Charles Kutscher, Auteur ; Frank Burkholder, Auteur ; J. Kathleen Stynes, 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 : Heat  losses  Solar  absorber-convertors  Sunlight Index. décimale : 621.47 Résumé : The thermal efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The thermal efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain the thermal efficiency curve. This paper describes this approach and also makes the case that there are advantages to plotting collector efficiency versus the difference between the operating temperature and the ambient temperature at which the receiver heat loss was measured divided by radiation to a fractional power (on the order of 1/3 but obtained via data regression)—as opposed to the difference between operating and ambient temperatures divided by the radiation. The results are shown to be robust over wide ranges of ambient temperature, sky temperature, and wind speed. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Spectral characterization of PSI's high-flux solar simulator / Ivo Alxneit 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) . - 05 p. Titre : Spectral characterization of PSI's high-flux solar simulator Type de document : texte imprimé Auteurs : Ivo Alxneit, Auteur ; Henri Schmit, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Lamps  Solar  absorber-convertors  Xenon Index. décimale : 621.47 Résumé : In this publication, the detailed spectral characterization of the concentrated radiation of PSI's 50 kW xenon arc lamp based solar simulator (HFSS) is reported. Spectra are presented for the range of 350–1600 nm recorded at different radial distances from the position of maximum concentration, i.e., from the center of the spot. The analysis shows that the relative intensity of the short wavelength region decreases with increasing radial distance from the center of the spot. At the same time, the relative contribution of the xenon emission lines increases. All spectra can be decomposed into a broad background described by a blackbody spectrum with a temperature of T = 6000 ± 200 K and the characteristic line spectrum of xenon. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Spectral characterization of PSI's high-flux solar simulator [texte imprimé] / Ivo Alxneit, Auteur ; Henri Schmit, Auteur . - 2012 . - 05 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 05 p. Mots-clés : Lamps  Solar  absorber-convertors  Xenon Index. décimale : 621.47 Résumé : In this publication, the detailed spectral characterization of the concentrated radiation of PSI's 50 kW xenon arc lamp based solar simulator (HFSS) is reported. Spectra are presented for the range of 350–1600 nm recorded at different radial distances from the position of maximum concentration, i.e., from the center of the spot. The analysis shows that the relative intensity of the short wavelength region decreases with increasing radial distance from the center of the spot. At the same time, the relative contribution of the xenon emission lines increases. All spectra can be decomposed into a broad background described by a blackbody spectrum with a temperature of T = 6000 ± 200 K and the characteristic line spectrum of xenon. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Energy and exergy analysis of a photovoltaic-thermal collector with natural air flow / A. Shahsavar 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) . - 10 p. Titre : Energy and exergy analysis of a photovoltaic-thermal collector with natural air flow Type de document : texte imprimé Auteurs : A. Shahsavar, Auteur ; M. Ameri, Auteur ; M. Gholampour, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Exergy  Photovoltaic  cells  Solar  absorber-convertors Index. décimale : 621.47 Résumé : The objective of present work is to analyze the energy and the exergy performance of a naturally ventilated photovoltaic-thermal (PV/T) air collector which is designed, manufactured and tested at a geographic location of Kerman, Iran. This PV/T collector is tested in both glazed and unglazed types. In this system, a thin metal sheet is used to improve heat extraction from the PV panels and consequently achieving higher thermal and electrical output. The metal sheet is suspended at the middle of an air channel in the studied PV/T air configuration. A theoretical model is developed and validated against experimental data, where good agreement between the predicted results and measured data is achieved. The validated model is then used to study the effect of the solar radiation, channel depth, collector length, and PV cell efficiency on total energy and exergy efficiency of the studied system. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Energy and exergy analysis of a photovoltaic-thermal collector with natural air flow [texte imprimé] / A. Shahsavar, Auteur ; M. Ameri, Auteur ; M. Gholampour, Auteur . - 2012 . - 10 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 10 p. Mots-clés : Exergy  Photovoltaic  cells  Solar  absorber-convertors Index. décimale : 621.47 Résumé : The objective of present work is to analyze the energy and the exergy performance of a naturally ventilated photovoltaic-thermal (PV/T) air collector which is designed, manufactured and tested at a geographic location of Kerman, Iran. This PV/T collector is tested in both glazed and unglazed types. In this system, a thin metal sheet is used to improve heat extraction from the PV panels and consequently achieving higher thermal and electrical output. The metal sheet is suspended at the middle of an air channel in the studied PV/T air configuration. A theoretical model is developed and validated against experimental data, where good agreement between the predicted results and measured data is achieved. The validated model is then used to study the effect of the solar radiation, channel depth, collector length, and PV cell efficiency on total energy and exergy efficiency of the studied system. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Potential for cogeneration through solar energy in the tissue industry / Roberto Gabbrielli 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) . - 12 p. Titre : Potential for cogeneration through solar energy in the tissue industry : technical and economic aspects Type de document : texte imprimé Auteurs : Roberto Gabbrielli, Auteur ; Francesco Zammori, Auteur Année de publication : 2012 Article en page(s) : 12 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Air  pollution  control  Cogeneration  Paper  industry  Paper  mills  Solar  power  stations  Thermal  power  stations Index. décimale : 621.47 Résumé : This paper investigates the feasibility of a solar cogeneration system, as a solution to reduce fossil fuel consumption and greenhouse gas emissions in a tissue mill, located in the industrial district of Lucca (North Italy). Although the paper sector has a high theoretical potential for the use of solar energy, the implementation of a solar thermal plant may not be economically sustainable, due to the expensive investment of such a system and to the uncertainty of future benefits. These issues are even more relevant in a moderate climate, where the high variability of the direct normal irradiance can prevent the technical feasibility of the plant. To demonstrate the possible use of solar energy in paper mills, a concentrating solar power plant with thermal storage, based on parabolic trough technology, has been chosen as a feasible solution for combined heat and power generation and its technical and economical performances have been evaluated through an extensive simulation analysis. The results obtained prove the feasibility of the proposed system and assure a good economic profitability. Results also show how the possibility of benefiting from economic incentives for renewable electric power generation is fundamental to reduce the payback period and to assure the profitability of the investment. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Potential for cogeneration through solar energy in the tissue industry : technical and economic aspects [texte imprimé] / Roberto Gabbrielli, Auteur ; Francesco Zammori, Auteur . - 2012 . - 12 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 12 p. Mots-clés : Air  pollution  control  Cogeneration  Paper  industry  Paper  mills  Solar  power  stations  Thermal  power  stations Index. décimale : 621.47 Résumé : This paper investigates the feasibility of a solar cogeneration system, as a solution to reduce fossil fuel consumption and greenhouse gas emissions in a tissue mill, located in the industrial district of Lucca (North Italy). Although the paper sector has a high theoretical potential for the use of solar energy, the implementation of a solar thermal plant may not be economically sustainable, due to the expensive investment of such a system and to the uncertainty of future benefits. These issues are even more relevant in a moderate climate, where the high variability of the direct normal irradiance can prevent the technical feasibility of the plant. To demonstrate the possible use of solar energy in paper mills, a concentrating solar power plant with thermal storage, based on parabolic trough technology, has been chosen as a feasible solution for combined heat and power generation and its technical and economical performances have been evaluated through an extensive simulation analysis. The results obtained prove the feasibility of the proposed system and assure a good economic profitability. Results also show how the possibility of benefiting from economic incentives for renewable electric power generation is fundamental to reduce the payback period and to assure the profitability of the investment. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Influence of phase-shift and overlap ratio on savonius wind turbine's performance / Chen, Jian 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) . - 09 p. Titre : Influence of phase-shift and overlap ratio on savonius wind turbine's performance Type de document : texte imprimé Auteurs : Chen, Jian, Auteur ; Jan Kumbernuss, Auteur ; Zhang Linhua, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Rotors  Wind  turbines Index. décimale : 621.47 Résumé : This paper presents the experimental results of the vertical axis wind turbine (VAWT), especially the Savonius rotors, which are developed for application on top of buildings due to lower wind speed compared with remote areas. The VAWT is regarded as the most suitable elegant candidate to be integrated with buildings for its relatively low operating noise, easy maintenance, and easy access. This study explored the interaction effect of the overlap ratio, phase-shift, and stage on the performance of the Savonius rotors in details. The results show that appropriate choice of the phase-shift angle according to the overlap ratio can not only increase the power coefficient of the Savonius rotors but also eliminate the negative static torque and smooth the variation of the static torque coefficient. Moreover, the performance of the two-stage rotors indicates that the two-stage rotor is the best candidate for this type of wind turbines or as a starting assistant for the Darrieus rotors. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Influence of phase-shift and overlap ratio on savonius wind turbine's performance [texte imprimé] / Chen, Jian, Auteur ; Jan Kumbernuss, Auteur ; Zhang Linhua, Auteur . - 2012 . - 09 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 09 p. Mots-clés : Rotors  Wind  turbines Index. décimale : 621.47 Résumé : This paper presents the experimental results of the vertical axis wind turbine (VAWT), especially the Savonius rotors, which are developed for application on top of buildings due to lower wind speed compared with remote areas. The VAWT is regarded as the most suitable elegant candidate to be integrated with buildings for its relatively low operating noise, easy maintenance, and easy access. This study explored the interaction effect of the overlap ratio, phase-shift, and stage on the performance of the Savonius rotors in details. The results show that appropriate choice of the phase-shift angle according to the overlap ratio can not only increase the power coefficient of the Savonius rotors but also eliminate the negative static torque and smooth the variation of the static torque coefficient. Moreover, the performance of the two-stage rotors indicates that the two-stage rotor is the best candidate for this type of wind turbines or as a starting assistant for the Darrieus rotors. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Research progress on improving the photovoltaic performance of polymer solar cells / Yanmin Wang 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) . - 09 p. Titre : Research progress on improving the photovoltaic performance of polymer solar cells Type de document : texte imprimé Auteurs : Yanmin Wang, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Annealing  Direct  energy  conversion  Electrochemical  electrodes  Polymers  Solar  cells Index. décimale : 621.47 Résumé : Although polymer materials possess the advantages such as low cost and easy fabrication of flexible and large-scale film for the application in photovoltaic devices, the performance of polymer-based solar cells, especially energy conversion efficiency is inferior to their inorganic counterpart due to the shorter charge diffusion length caused by the comparatively lower electric field between the electrodes. This paper reviewed the strategies to improve their photovoltaic properties mainly concentrated on modifying the polymer materials and ameliorating the device configuration. First, polythiophene (PT), poly(phenylene vinylene) (PPV), polyfullerene, and other novel polymer materials were introduced and the effective ways to modify their derivatives with more advantages were described in detail, for instance, copolymerization, incorporating additives and dyes, etc. Furthermore, the content of ameliorating the device configuration encompassed on inverted architecture, tandem structure, the introduction of buffer layers, thermal annealing, and the integration of optimized conditions. Finally, the effects of the improvement methods were concisely summarized, and the perspectives of the future research were put forth. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Research progress on improving the photovoltaic performance of polymer solar cells [texte imprimé] / Yanmin Wang, Auteur . - 2012 . - 09 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 09 p. Mots-clés : Annealing  Direct  energy  conversion  Electrochemical  electrodes  Polymers  Solar  cells Index. décimale : 621.47 Résumé : Although polymer materials possess the advantages such as low cost and easy fabrication of flexible and large-scale film for the application in photovoltaic devices, the performance of polymer-based solar cells, especially energy conversion efficiency is inferior to their inorganic counterpart due to the shorter charge diffusion length caused by the comparatively lower electric field between the electrodes. This paper reviewed the strategies to improve their photovoltaic properties mainly concentrated on modifying the polymer materials and ameliorating the device configuration. First, polythiophene (PT), poly(phenylene vinylene) (PPV), polyfullerene, and other novel polymer materials were introduced and the effective ways to modify their derivatives with more advantages were described in detail, for instance, copolymerization, incorporating additives and dyes, etc. Furthermore, the content of ameliorating the device configuration encompassed on inverted architecture, tandem structure, the introduction of buffer layers, thermal annealing, and the integration of optimized conditions. Finally, the effects of the improvement methods were concisely summarized, and the perspectives of the future research were put forth. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

The effect of booster reflectors on the photovoltaic water pumping system performance / H. Tabaei 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) . - 04 p. Titre : The effect of booster reflectors on the photovoltaic water pumping system performance Type de document : texte imprimé Auteurs : H. Tabaei, Auteur ; M. Ameri, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Aluminium  Pumps  Solar  absorber-convertors  Solar  cells  Solar  energy  concentrators  Stainless  steel Index. décimale : 621.47 Résumé : In this work, the experimental results of a designed and installed photovoltaic water pump system with static concentrator are presented. The tests have been conducted in outdoor condition in Kerman (Latitude 30 deg 17[prime] and longitude 57 deg 50[prime]), Iran. The performance of photovoltaic water pumping system is evaluated for both stainless steel 304 and aluminum foil reflectors. Through this study, it is found that the performance of the photovoltaic (PV) water pumping system was improved by using these two types of reflectors; but results show that aluminum foil reflector is more efficient than stainless steel 304 reflector. Measurements indicate that output power from the PV panels can be increased in the order of 14% and 8.5% due to the use of aluminum foil and stainless steel 304 reflectors, respectively. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] The effect of booster reflectors on the photovoltaic water pumping system performance [texte imprimé] / H. Tabaei, Auteur ; M. Ameri, Auteur . - 2012 . - 04 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 04 p. Mots-clés : Aluminium  Pumps  Solar  absorber-convertors  Solar  cells  Solar  energy  concentrators  Stainless  steel Index. décimale : 621.47 Résumé : In this work, the experimental results of a designed and installed photovoltaic water pump system with static concentrator are presented. The tests have been conducted in outdoor condition in Kerman (Latitude 30 deg 17[prime] and longitude 57 deg 50[prime]), Iran. The performance of photovoltaic water pumping system is evaluated for both stainless steel 304 and aluminum foil reflectors. Through this study, it is found that the performance of the photovoltaic (PV) water pumping system was improved by using these two types of reflectors; but results show that aluminum foil reflector is more efficient than stainless steel 304 reflector. Measurements indicate that output power from the PV panels can be increased in the order of 14% and 8.5% due to the use of aluminum foil and stainless steel 304 reflectors, respectively. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Technical and economic performance analysis of utilization of solar energy in indoor swimming pools / Olcay Kincay 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) . - 08 p. Titre : Technical and economic performance analysis of utilization of solar energy in indoor swimming pools : an application Type de document : texte imprimé Auteurs : Olcay Kincay, Auteur ; Zafer Utlu, Auteur ; Ugur Akbulut, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Costing  Heat  losses  Heat  transfer  Investment  Power  generation  economics  Solar  absorber-convertors  Solar  power  stations Index. décimale : 621.47 Résumé : In this study, technical and economic performance analyses are conducted in order to determine the optimum collector surface area for indoor swimming pools. Required heat and economical conditions are taken into consideration while performing these evaluations. A brief summary of solar energy source and heat transfer equations for the Olympic pools are given. An Olympic swimming pool is assumed to be in different cities, and energy losses are calculated. For our sample Olympic pool, convective heat loss obtained is −3.86 kW and evaporative heat loss obtained is 265 kW. Total heat loss always maximum in January from 384 kW to 455.1 kW. Solar energy gain (assumption 1000 m2 collector area) and energy gain from boiler for different cities are calculated as maximum solar energy gain in July between 160 and 175 kW and minimum in January between 54.9 and 82 kW. High investment costs for solar power systems are responsible for low value of the reduction rate. Also, according to the energy demand and economical conditions, technical evaluations are performed in order to obtain optimum surface collector area, and economical analyses are conducted using unified cost method. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Technical and economic performance analysis of utilization of solar energy in indoor swimming pools : an application [texte imprimé] / Olcay Kincay, Auteur ; Zafer Utlu, Auteur ; Ugur Akbulut, Auteur . - 2012 . - 08 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 08 p. Mots-clés : Costing  Heat  losses  Heat  transfer  Investment  Power  generation  economics  Solar  absorber-convertors  Solar  power  stations Index. décimale : 621.47 Résumé : In this study, technical and economic performance analyses are conducted in order to determine the optimum collector surface area for indoor swimming pools. Required heat and economical conditions are taken into consideration while performing these evaluations. A brief summary of solar energy source and heat transfer equations for the Olympic pools are given. An Olympic swimming pool is assumed to be in different cities, and energy losses are calculated. For our sample Olympic pool, convective heat loss obtained is −3.86 kW and evaporative heat loss obtained is 265 kW. Total heat loss always maximum in January from 384 kW to 455.1 kW. Solar energy gain (assumption 1000 m2 collector area) and energy gain from boiler for different cities are calculated as maximum solar energy gain in July between 160 and 175 kW and minimum in January between 54.9 and 82 kW. High investment costs for solar power systems are responsible for low value of the reduction rate. Also, according to the energy demand and economical conditions, technical evaluations are performed in order to obtain optimum surface collector area, and economical analyses are conducted using unified cost method. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Characteristics of global solar radiation monitor utilizing solar cells / A. Ibrahim 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) . - 04 p. Titre : Characteristics of global solar radiation monitor utilizing solar cells Type de document : texte imprimé Auteurs : A. Ibrahim, Auteur ; M. R. I. Ramadan, Auteur Année de publication : 2012 Article en page(s) : 04 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Digital  multimeters  Solar  cells  Solar  radiation Index. décimale : 621.47 Résumé : This brief note examines the characteristics of solar cells from the standpoint of developing a global solar radiation monitor. The study is performed using a simplified photovoltaic test monitor manufactured, a single crystal p-type czochraliski (CZ) silicon solar cell of the construction n+pp++ passivated emitter solar cell coupled to a fluke 73 digital multimeter. The short circuit current density (Jsc) is examined during a complete test day from 8:40 AM to 7:40 PM. Subsequently, the test monitor is used for checking the accuracy of transfer operations of solar radiation. The results obtained by the test monitor utilizing solar cells are good due to: (a) it is simple in construction, (b) it exhibits a good response to all solar radiation variations, and (c) it works without an electric power supply. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Characteristics of global solar radiation monitor utilizing solar cells [texte imprimé] / A. Ibrahim, Auteur ; M. R. I. Ramadan, Auteur . - 2012 . - 04 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 04 p. Mots-clés : Digital  multimeters  Solar  cells  Solar  radiation Index. décimale : 621.47 Résumé : This brief note examines the characteristics of solar cells from the standpoint of developing a global solar radiation monitor. The study is performed using a simplified photovoltaic test monitor manufactured, a single crystal p-type czochraliski (CZ) silicon solar cell of the construction n+pp++ passivated emitter solar cell coupled to a fluke 73 digital multimeter. The short circuit current density (Jsc) is examined during a complete test day from 8:40 AM to 7:40 PM. Subsequently, the test monitor is used for checking the accuracy of transfer operations of solar radiation. The results obtained by the test monitor utilizing solar cells are good due to: (a) it is simple in construction, (b) it exhibits a good response to all solar radiation variations, and (c) it works without an electric power supply. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

Design of an extra-tall mast above blade-tip heights for wind resource assessments across complex terrain regions / Carole A. Womeldorf 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) . - 07 p. Titre : Design of an extra-tall mast above blade-tip heights for wind resource assessments across complex terrain regions Type de document : texte imprimé Auteurs : Carole A. Womeldorf, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Blades  Design  engineering  Wind  turbines Index. décimale : 621.47 Résumé : Wind energy predictions for many rural, complex terrain regions are based solely on large-scale meteorological models that may poorly characterize the local resource. Changes in government policies, energy economics, and wind technologies suggest that the best wind resources across such a complex terrain region in southeast Ohio may be economically viable. The wind energy and assessment visualization (WEAV) assessment approach is a meso-scale strategy to locate the best resource in a marginal wind region. The measurement component is described here. Wind characteristics measurements on a communications tower at six heights up to 240 m, are being acquired. This data will be input into a complex-terrain wind simulator with terrain information to model the wind resource across approximately 2000 square miles (5200 km2). Advantages of the WEAV assessment strategy include explicit measurement of wind shear and velocities, long-term characterization of the free stream velocity field, and evaluation of a much larger assessment region. Included is a description of, the motivation for and advantages of this approach, details of the design, installation, and challenges of an extra-tall tower wind measurements, and a discussion of the economics of both Class 2 wind (~250 W/m2) and the WEAV assessment approach compared with conventional wind assessments. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...] [article] Design of an extra-tall mast above blade-tip heights for wind resource assessments across complex terrain regions [texte imprimé] / Carole A. Womeldorf, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 1 (Fevrier 2011) . - 07 p. Mots-clés : Blades  Design  engineering  Wind  turbines Index. décimale : 621.47 Résumé : Wind energy predictions for many rural, complex terrain regions are based solely on large-scale meteorological models that may poorly characterize the local resource. Changes in government policies, energy economics, and wind technologies suggest that the best wind resources across such a complex terrain region in southeast Ohio may be economically viable. The wind energy and assessment visualization (WEAV) assessment approach is a meso-scale strategy to locate the best resource in a marginal wind region. The measurement component is described here. Wind characteristics measurements on a communications tower at six heights up to 240 m, are being acquired. This data will be input into a complex-terrain wind simulator with terrain information to model the wind resource across approximately 2000 square miles (5200 km2). Advantages of the WEAV assessment strategy include explicit measurement of wind shear and velocities, long-term characterization of the free stream velocity field, and evaluation of a much larger assessment region. Included is a description of, the motivation for and advantages of this approach, details of the design, installation, and challenges of an extra-tall tower wind measurements, and a discussion of the economics of both Class 2 wind (~250 W/m2) and the WEAV assessment approach compared with conventional wind assessments. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000001 [...]

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