Dépouillements

Assessment of load extrapolation methods for wind turbines / Henrik Stensgaard Toft in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 08 p. Titre : Assessment of load extrapolation methods for wind turbines Type de document : texte imprimé Auteurs : Henrik Stensgaard Toft, Auteur ; John Dalsgaard Sørensen, Auteur ; Dick Veldkamp, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Extrapolation  Gaussian  processes  Load  (electric)  Wind  turbines Index. décimale : 621.47 Résumé : In the present paper, methods for statistical load extrapolation of wind-turbine response are studied using a stationary Gaussian process model, which has approximately the same spectral properties as the response for the out-of-plane bending moment of a wind-turbine blade. For a Gaussian process, an approximate analytical solution for the distribution of the peaks is given by Rice. In the present paper, three different methods for statistical load extrapolation are compared with the analytical solution for one mean wind speed. The methods considered are global maxima, block maxima, and the peak over threshold method with two different threshold values. The comparisons show that the goodness of fit for the local distribution has a significant influence on the results, but the peak over threshold method with a threshold value on the mean plus 1.4 standard deviations generally gives the best results. By considering Gaussian processes for 12 mean wind speeds, the “fitting before aggregation” and “aggregation before fitting” approaches are studied. The results show that the fitting before aggregation approach gives the best results. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Assessment of load extrapolation methods for wind turbines [texte imprimé] / Henrik Stensgaard Toft, Auteur ; John Dalsgaard Sørensen, Auteur ; Dick Veldkamp, Auteur . - 2012 . - 08 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 08 p. Mots-clés : Extrapolation  Gaussian  processes  Load  (electric)  Wind  turbines Index. décimale : 621.47 Résumé : In the present paper, methods for statistical load extrapolation of wind-turbine response are studied using a stationary Gaussian process model, which has approximately the same spectral properties as the response for the out-of-plane bending moment of a wind-turbine blade. For a Gaussian process, an approximate analytical solution for the distribution of the peaks is given by Rice. In the present paper, three different methods for statistical load extrapolation are compared with the analytical solution for one mean wind speed. The methods considered are global maxima, block maxima, and the peak over threshold method with two different threshold values. The comparisons show that the goodness of fit for the local distribution has a significant influence on the results, but the peak over threshold method with a threshold value on the mean plus 1.4 standard deviations generally gives the best results. By considering Gaussian processes for 12 mean wind speeds, the “fitting before aggregation” and “aggregation before fitting” approaches are studied. The results show that the fitting before aggregation approach gives the best results. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Convective heat transfer coefficients in a building-integrated photovoltaic/thermal system / Luis M. Candanedo in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 14 p. Titre : Convective heat transfer coefficients in a building-integrated photovoltaic/thermal system Type de document : texte imprimé Auteurs : Luis M. Candanedo, Auteur ; Andreas Athienitis, Auteur ; Kwang-Wook Park, Auteur Année de publication : 2012 Article en page(s) : 14 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Building  integrated  photovoltaics  Convection  Electricity  Laminar  flow  Solar  cells  Solar  power  stations  Turbulence Index. décimale : 621.47 Résumé : This paper presents an experimental study for the development of convective heat transfer correlations for an open loop air-based building-integrated photovoltaic/thermal (BIPV/T) system. The BIPV/T system absorbs solar energy on the top surface, which includes the photovoltaic panels and generates electricity while also heating air drawn by a variable speed fan through a channel formed by the top roof surface with the photovoltaic modules and an insulated attic layer. The BIPV/T system channel has a length/hydraulic diameter ratio of 38, which is representative of a BIPV/T roof system for 30–45 deg tilt angles. Because of the heating asymmetry in the BIPV/T channel, two average Nusselt number correlations are reported as a function of Reynolds number: one for the top heated surface and the other for the bottom surface. For the top heated surface, the Nusselt number is in the range of 6–48 for Reynolds numbers ranging from 250 to 7500. For the bottom insulated surface, the Nusselt number is in the range of 22–68 for Reynolds numbers ranging from 800 to 7060. This paper presents correlations for the average Nusselt number as a function of Reynolds number; this correlation is considered adequate for the design of BIPV/T systems where forced convection dominates. Local Nusselt number distributions are also presented for laminar and turbulent flow conditions. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Convective heat transfer coefficients in a building-integrated photovoltaic/thermal system [texte imprimé] / Luis M. Candanedo, Auteur ; Andreas Athienitis, Auteur ; Kwang-Wook Park, Auteur . - 2012 . - 14 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 14 p. Mots-clés : Building  integrated  photovoltaics  Convection  Electricity  Laminar  flow  Solar  cells  Solar  power  stations  Turbulence Index. décimale : 621.47 Résumé : This paper presents an experimental study for the development of convective heat transfer correlations for an open loop air-based building-integrated photovoltaic/thermal (BIPV/T) system. The BIPV/T system absorbs solar energy on the top surface, which includes the photovoltaic panels and generates electricity while also heating air drawn by a variable speed fan through a channel formed by the top roof surface with the photovoltaic modules and an insulated attic layer. The BIPV/T system channel has a length/hydraulic diameter ratio of 38, which is representative of a BIPV/T roof system for 30–45 deg tilt angles. Because of the heating asymmetry in the BIPV/T channel, two average Nusselt number correlations are reported as a function of Reynolds number: one for the top heated surface and the other for the bottom surface. For the top heated surface, the Nusselt number is in the range of 6–48 for Reynolds numbers ranging from 250 to 7500. For the bottom insulated surface, the Nusselt number is in the range of 22–68 for Reynolds numbers ranging from 800 to 7060. This paper presents correlations for the average Nusselt number as a function of Reynolds number; this correlation is considered adequate for the design of BIPV/T systems where forced convection dominates. Local Nusselt number distributions are also presented for laminar and turbulent flow conditions. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Analysis of heat storage and delivery of a thermocline tank having solid filler material / Jon T. Van Lew in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 10 p. Titre : Analysis of heat storage and delivery of a thermocline tank having solid filler material Type de document : texte imprimé Auteurs : Jon T. Van Lew, Auteur ; Peiwen Li, Auteur ; Cho Lik Chan, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Numerical  analysis  Solar  power  stations  Thermal  energy  storage  Thermal  power  stations Index. décimale : 621.47 Résumé : Thermal storage has been considered as an important measure to extend the operation of a concentrated solar power plant by providing more electricity and meeting the peak demand of power in the time period from dusk to late night everyday, or even providing power on cloudy days. Discussed in this paper is thermal energy storage in a thermocline tank having a solid filler material. To provide more knowledge for designing and operating of such a thermocline storage system, this paper firstly presents the application of method of characteristics for numerically predicting the heat charging and discharging process in a packed bed thermocline storage tank. Nondimensional analysis of governing equations and numerical solution schemes using the method of characteristics were presented. The numerical method proved to be very efficient, accurate; required minimal computations; and proved versatile in simulating various operational conditions for which analytical methods cannot always provide solutions. Available analytical solutions under simple boundary and initial conditions were used to validate the numerical modeling and computation. A validation of the modeling by comparing the simulation results to experimental test data from literature also confirmed the effectiveness of the model and the related numerical solution method. Finally, design procedures using the numerical modeling tool were discussed and other issues related to operation of a thermocline storage system were also studied. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Analysis of heat storage and delivery of a thermocline tank having solid filler material [texte imprimé] / Jon T. Van Lew, Auteur ; Peiwen Li, Auteur ; Cho Lik Chan, Auteur . - 2012 . - 10 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 10 p. Mots-clés : Numerical  analysis  Solar  power  stations  Thermal  energy  storage  Thermal  power  stations Index. décimale : 621.47 Résumé : Thermal storage has been considered as an important measure to extend the operation of a concentrated solar power plant by providing more electricity and meeting the peak demand of power in the time period from dusk to late night everyday, or even providing power on cloudy days. Discussed in this paper is thermal energy storage in a thermocline tank having a solid filler material. To provide more knowledge for designing and operating of such a thermocline storage system, this paper firstly presents the application of method of characteristics for numerically predicting the heat charging and discharging process in a packed bed thermocline storage tank. Nondimensional analysis of governing equations and numerical solution schemes using the method of characteristics were presented. The numerical method proved to be very efficient, accurate; required minimal computations; and proved versatile in simulating various operational conditions for which analytical methods cannot always provide solutions. Available analytical solutions under simple boundary and initial conditions were used to validate the numerical modeling and computation. A validation of the modeling by comparing the simulation results to experimental test data from literature also confirmed the effectiveness of the model and the related numerical solution method. Finally, design procedures using the numerical modeling tool were discussed and other issues related to operation of a thermocline storage system were also studied. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Numerical investigation of natural convection loss from cavity receivers in solar dish applications / S. Paitoonsurikarn in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 10 p. Titre : Numerical investigation of natural convection loss from cavity receivers in solar dish applications Type de document : texte imprimé Auteurs : S. Paitoonsurikarn, Auteur ; K. Lovegrove, Auteur ; G. Hughes, Auteur Année de publication : 2012 Article en page(s) : 10 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Natural  convection  Solar  absorber-convertors Index. décimale : 621.47 Résumé : In open cavity receivers employed in solar paraboloidal dish applications, natural convection occurs and contributes a significant fraction of energy loss. Its characteristics hence need to be clarified so that it can be effectively minimized in order to improve the system efficiency. The investigation of natural convection loss from cavity receivers was undertaken numerically and was validated using the published experimental results for four different receiver geometries. A good agreement between experimental and numerical results was obtained. Furthermore, the numerical results of all receivers were qualitatively comparable to the predictions by other available correlations hitherto, although it was found that each correlation has a limited range of applicability arising from the particular cavity geometry and experimental conditions used to derive it. To address this shortcoming, a new correlation based on the numerical results for three of the above four receivers has been proposed. The correlation employs a new concept of an ensemble cavity length scale, to take into account the combined effects of cavity geometry and inclination. Despite a wide variety of cavity geometries and operating conditions, the proposed correlation predicts approximately 50% of the data within ±20% and 90% of the data within ±50%. This is better than any of the other correlations published to date. The new correlation is also simpler to use than the most accurate of those previously published. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Numerical investigation of natural convection loss from cavity receivers in solar dish applications [texte imprimé] / S. Paitoonsurikarn, Auteur ; K. Lovegrove, Auteur ; G. Hughes, Auteur . - 2012 . - 10 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 10 p. Mots-clés : Natural  convection  Solar  absorber-convertors Index. décimale : 621.47 Résumé : In open cavity receivers employed in solar paraboloidal dish applications, natural convection occurs and contributes a significant fraction of energy loss. Its characteristics hence need to be clarified so that it can be effectively minimized in order to improve the system efficiency. The investigation of natural convection loss from cavity receivers was undertaken numerically and was validated using the published experimental results for four different receiver geometries. A good agreement between experimental and numerical results was obtained. Furthermore, the numerical results of all receivers were qualitatively comparable to the predictions by other available correlations hitherto, although it was found that each correlation has a limited range of applicability arising from the particular cavity geometry and experimental conditions used to derive it. To address this shortcoming, a new correlation based on the numerical results for three of the above four receivers has been proposed. The correlation employs a new concept of an ensemble cavity length scale, to take into account the combined effects of cavity geometry and inclination. Despite a wide variety of cavity geometries and operating conditions, the proposed correlation predicts approximately 50% of the data within ±20% and 90% of the data within ±50%. This is better than any of the other correlations published to date. The new correlation is also simpler to use than the most accurate of those previously published. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Evaluation and validation of equivalent circuit photovoltaic solar cell performance models / Matthew T. Boyd in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 13 p. Titre : Evaluation and validation of equivalent circuit photovoltaic solar cell performance models Type de document : texte imprimé Auteurs : Matthew T. Boyd, Auteur ; Sanford A. Klein, Auteur ; Douglas T. Reindl, Auteur Année de publication : 2012 Article en page(s) : 13 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Glazes  Photovoltaic  cells  Sensitivity  analysis  Solar  cells Index. décimale : 621.47 Résumé : The “five-parameter model” is a performance model for photovoltaic solar cells that predicts the voltage and current output by representing the cells as an equivalent electrical circuit with radiation and temperature-dependent components. An important feature of the five-parameter model is that its parameters can be determined using data commonly provided by module manufacturers on their published datasheets. This paper documents the predictive capability of the five-parameter model and proposes modifications to improve its performance using approximately 30 days of field-measured meteorological and module data from a wide range of cell technologies, including monocrystalline, polycrystalline, amorphous silicon, and copper indium diselenide (CIS). The standard five-parameter model is capable of predicting the performance of monocrystalline and polycrystalline silicon modules within approximately 6% RMS but is slightly less accurate for a thin-film CIS and an amorphous silicon array. Errors for the amorphous technology are reduced to approximately 5% RMS by using input data obtained after the module underwent an initial degradation in output due to aging. The robustness and possible improvements to the five-parameter model were also evaluated. A sensitivity analysis of the five-parameter model shows that all model inputs that are difficult to determine and not provided by manufacturer datasheets such as the glazing material properties, the semiconductor band gap energy, and the ground reflectance may be represented by approximate values independent of the PV technology. Modifications to the five-parameter model tested during this research did not appreciably improve the overall model performance. Additional dependence introduced by a seven-parameter model had a less than 1% RMS effect on maximum power predictions for the amorphous technology and increased the modeling errors for this array 4% RMS at open-circuit conditions. Adding a current sink to the equivalent circuit to better model recombination currents had little effect on the model behavior. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Evaluation and validation of equivalent circuit photovoltaic solar cell performance models [texte imprimé] / Matthew T. Boyd, Auteur ; Sanford A. Klein, Auteur ; Douglas T. Reindl, Auteur . - 2012 . - 13 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 13 p. Mots-clés : Glazes  Photovoltaic  cells  Sensitivity  analysis  Solar  cells Index. décimale : 621.47 Résumé : The “five-parameter model” is a performance model for photovoltaic solar cells that predicts the voltage and current output by representing the cells as an equivalent electrical circuit with radiation and temperature-dependent components. An important feature of the five-parameter model is that its parameters can be determined using data commonly provided by module manufacturers on their published datasheets. This paper documents the predictive capability of the five-parameter model and proposes modifications to improve its performance using approximately 30 days of field-measured meteorological and module data from a wide range of cell technologies, including monocrystalline, polycrystalline, amorphous silicon, and copper indium diselenide (CIS). The standard five-parameter model is capable of predicting the performance of monocrystalline and polycrystalline silicon modules within approximately 6% RMS but is slightly less accurate for a thin-film CIS and an amorphous silicon array. Errors for the amorphous technology are reduced to approximately 5% RMS by using input data obtained after the module underwent an initial degradation in output due to aging. The robustness and possible improvements to the five-parameter model were also evaluated. A sensitivity analysis of the five-parameter model shows that all model inputs that are difficult to determine and not provided by manufacturer datasheets such as the glazing material properties, the semiconductor band gap energy, and the ground reflectance may be represented by approximate values independent of the PV technology. Modifications to the five-parameter model tested during this research did not appreciably improve the overall model performance. Additional dependence introduced by a seven-parameter model had a less than 1% RMS effect on maximum power predictions for the amorphous technology and increased the modeling errors for this array 4% RMS at open-circuit conditions. Adding a current sink to the equivalent circuit to better model recombination currents had little effect on the model behavior. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Monitoring solar home systems with pulse width modulation charge control / Nathaniel J. Williams in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Titre : Monitoring solar home systems with pulse width modulation charge control Type de document : texte imprimé Auteurs : Nathaniel J. Williams, Auteur ; E. Ernest Van Dyk, Auteur ; Frederik J. Vorster, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Data  loggers  Photovoltaic  power  systems  Power  grids  Power  supply  quality  PWM  power  convertors  Secondary  cells Index. décimale : 621.47 Résumé : With the high cost of grid extension and approximately 1.6 billion people still living without electrical services, the solar home system is an important technology in the alleviation of rural energy poverty across the developing world. The performance monitoring and analysis of these systems provide insights leading to improvements in system design and implementation in order to ensure high quality and robust energy supply in remote locations. Most small solar home systems now use charge controllers using pulse width modulation (PWM) to regulate the charge current to the battery. A rapid variation in current and voltage resulting from PWM creates monitoring challenges, which, if not carefully considered in the design of the monitoring system, can result in the erroneous measurement of photovoltaic (PV) power. In order to characterize and clarify the measurement process during PWM, a mathematical model was developed to reproduce and simulate measured data. The effects of matched scan and PWM frequency were studied with the model, and an algorithm was devised to select appropriate scan rates to ensure that a representative sample of measurements is acquired. Furthermore, estimation methods were developed to correct for measurement errors due to factors such as nonzero “short circuit” voltage and current/voltage peak mismatches. A more sophisticated algorithm is then discussed to more accurately measure PV power using highly programmable data loggers. The results produced by the various methods are compared and reveal a significant error in the measurement of PV power without corrective action. Estimation methods prove to be effective in certain cases but are susceptible to error during conditions of variable irradiance. The effect of the measurement error has been found to depend strongly on the duty cycle of PWM as well as the relationship between scan rate and PWM frequency. The energy measurement error over 1 day depends on insolation and system conditions as well as on system design. On a sunny day, under a daily load of about 20 A h, the net error in PV energy is found to be 1%, whereas a system with a high initial battery state of charge under similar conditions and no load produced an error of 47.6%. This study shows the importance of data logger selection and programming in monitoring accurately the energy provided by solar home systems. When appropriately considered, measurement errors can be avoided or reduced without investment in more expensive measurement equipment. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Monitoring solar home systems with pulse width modulation charge control [texte imprimé] / Nathaniel J. Williams, Auteur ; E. Ernest Van Dyk, Auteur ; Frederik J. Vorster, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Mots-clés : Data  loggers  Photovoltaic  power  systems  Power  grids  Power  supply  quality  PWM  power  convertors  Secondary  cells Index. décimale : 621.47 Résumé : With the high cost of grid extension and approximately 1.6 billion people still living without electrical services, the solar home system is an important technology in the alleviation of rural energy poverty across the developing world. The performance monitoring and analysis of these systems provide insights leading to improvements in system design and implementation in order to ensure high quality and robust energy supply in remote locations. Most small solar home systems now use charge controllers using pulse width modulation (PWM) to regulate the charge current to the battery. A rapid variation in current and voltage resulting from PWM creates monitoring challenges, which, if not carefully considered in the design of the monitoring system, can result in the erroneous measurement of photovoltaic (PV) power. In order to characterize and clarify the measurement process during PWM, a mathematical model was developed to reproduce and simulate measured data. The effects of matched scan and PWM frequency were studied with the model, and an algorithm was devised to select appropriate scan rates to ensure that a representative sample of measurements is acquired. Furthermore, estimation methods were developed to correct for measurement errors due to factors such as nonzero “short circuit” voltage and current/voltage peak mismatches. A more sophisticated algorithm is then discussed to more accurately measure PV power using highly programmable data loggers. The results produced by the various methods are compared and reveal a significant error in the measurement of PV power without corrective action. Estimation methods prove to be effective in certain cases but are susceptible to error during conditions of variable irradiance. The effect of the measurement error has been found to depend strongly on the duty cycle of PWM as well as the relationship between scan rate and PWM frequency. The energy measurement error over 1 day depends on insolation and system conditions as well as on system design. On a sunny day, under a daily load of about 20 A h, the net error in PV energy is found to be 1%, whereas a system with a high initial battery state of charge under similar conditions and no load produced an error of 47.6%. This study shows the importance of data logger selection and programming in monitoring accurately the energy provided by solar home systems. When appropriately considered, measurement errors can be avoided or reduced without investment in more expensive measurement equipment. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Distribution of emerged energy for daylight illuminate on prismatic elements / Shih-Chuan Yeh in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 09 p. Titre : Distribution of emerged energy for daylight illuminate on prismatic elements Type de document : texte imprimé Auteurs : Shih-Chuan Yeh, Auteur ; Allen Jong-Woei Whang, Auteur ; Horng-Ching Hsiao, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Optical  prisms  Solar  absorber-convertors  Solar  power Index. décimale : 621.47 Résumé : Prismatic elements are typical devices of natural light illumination system for redirecting and collecting daylight. Based on the principles of optics, this paper presents a simple mathematical matrix ray-tracing methodology through which a detailed intensity distribution of parallel light beam incident onto a right angled prism from different incident angles can be calculated precisely. We also present the distribution of the secondary emerged intensity from a prism illuminated by the emerged light of an adjacent prism. The direction, concentration, and distribution of intensity of the emerged light from the parallel light incident onto a surface of the right-angle prism, as well as daylight illuminate on a prismatic collector, are precisely calculated. The detailed calculation of the emerged light re-incident onto the adjacent prism or emerged out of the prismatic element presented that most of daylight are directly emerged out and are confined in some directions at earlier morning and afternoon, and the emerged light re-incident into the adjacent prism at noon around. This detailed calculation model of parallel light beam incident to a prismatic element can be applied to the hybrid natural light illumination system, as well as to the prism-relative solar illumination system for the improvement of efficiency. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Distribution of emerged energy for daylight illuminate on prismatic elements [texte imprimé] / Shih-Chuan Yeh, Auteur ; Allen Jong-Woei Whang, Auteur ; Horng-Ching Hsiao, Auteur . - 2012 . - 09 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 09 p. Mots-clés : Optical  prisms  Solar  absorber-convertors  Solar  power Index. décimale : 621.47 Résumé : Prismatic elements are typical devices of natural light illumination system for redirecting and collecting daylight. Based on the principles of optics, this paper presents a simple mathematical matrix ray-tracing methodology through which a detailed intensity distribution of parallel light beam incident onto a right angled prism from different incident angles can be calculated precisely. We also present the distribution of the secondary emerged intensity from a prism illuminated by the emerged light of an adjacent prism. The direction, concentration, and distribution of intensity of the emerged light from the parallel light incident onto a surface of the right-angle prism, as well as daylight illuminate on a prismatic collector, are precisely calculated. The detailed calculation of the emerged light re-incident onto the adjacent prism or emerged out of the prismatic element presented that most of daylight are directly emerged out and are confined in some directions at earlier morning and afternoon, and the emerged light re-incident into the adjacent prism at noon around. This detailed calculation model of parallel light beam incident to a prismatic element can be applied to the hybrid natural light illumination system, as well as to the prism-relative solar illumination system for the improvement of efficiency. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Carbon dioxide reforming of methane in directly irradiated solar reactor with porcupine absorber / Rachamim Rubin in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 05 p. Titre : Carbon dioxide reforming of methane in directly irradiated solar reactor with porcupine absorber Type de document : texte imprimé Auteurs : Rachamim Rubin, Auteur ; Jacob Karni, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Carbon  compounds  Chemical  energy  conversion  Poles  and  towers  Ruthenium  Solar  absorber-convertors Index. décimale : 621.47 Résumé : A new solar volumetric reactor for CO2 reforming of CH4 was tested at the Solar Tower of the Weizmann Institute of Science. The reactor design was based on extensive previous experimental work with a volumetric receiver for heating air and simulation of volumetric reformer. The main parts of the reactor were a conical quartz window and a Porcupine absorber as the surface where chemical and thermal energy conversion took place. A specially developed ruthenium catalyst was used. The CO2 to CH4 ratio was about 1:1.2, and the total inlet flow rate was between 100 slpm and 235 slpm (slpm denotes standard liter per minute). The maximum absorber temperature was kept below 1450 K. The conversion of CH4 reached 85%. The total power absorbed was between 10.3 kW and 18.2 kW, of which the thermal power part was 2.3–4.5 kW and the stored chemical enrichment was 7.5–13.7 kW. The results indicate that this type of volumetric reactor can be used effectively for CO2 reforming of CH4, and further work aimed at improving the total efficiency of the system is in progress. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Carbon dioxide reforming of methane in directly irradiated solar reactor with porcupine absorber [texte imprimé] / Rachamim Rubin, Auteur ; Jacob Karni, Auteur . - 2012 . - 05 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 05 p. Mots-clés : Carbon  compounds  Chemical  energy  conversion  Poles  and  towers  Ruthenium  Solar  absorber-convertors Index. décimale : 621.47 Résumé : A new solar volumetric reactor for CO2 reforming of CH4 was tested at the Solar Tower of the Weizmann Institute of Science. The reactor design was based on extensive previous experimental work with a volumetric receiver for heating air and simulation of volumetric reformer. The main parts of the reactor were a conical quartz window and a Porcupine absorber as the surface where chemical and thermal energy conversion took place. A specially developed ruthenium catalyst was used. The CO2 to CH4 ratio was about 1:1.2, and the total inlet flow rate was between 100 slpm and 235 slpm (slpm denotes standard liter per minute). The maximum absorber temperature was kept below 1450 K. The conversion of CH4 reached 85%. The total power absorbed was between 10.3 kW and 18.2 kW, of which the thermal power part was 2.3–4.5 kW and the stored chemical enrichment was 7.5–13.7 kW. The results indicate that this type of volumetric reactor can be used effectively for CO2 reforming of CH4, and further work aimed at improving the total efficiency of the system is in progress. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

A simplified model for radiative transfer in building enclosures with low emissivity walls / Frédéric Miranville in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 13 p. Titre : A simplified model for radiative transfer in building enclosures with low emissivity walls : development and application to radiant barrier insulation Type de document : texte imprimé Auteurs : Frédéric Miranville, Auteur ; Philippe Lauret, Auteur ; Mario Medina, Auteur Année de publication : 2012 Article en page(s) : 13 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Building  Heat  transfer  Radiative  transfer  Roofs  Thermal  insulation  Walls Index. décimale : 621.47 Résumé : This paper deals with a simplified model of radiative heat transfer in building enclosures with low emissivity walls. The approach is based on an existing simplified model, well known and used in building multizone simulation codes, for the long wave exchanges in building enclosures. This method is simply extended to the case of a cavity including a very low emissivity wall, and it is shown that the obtained formalism is similar to the one used in the case of the based model, convenient for enclosures with only black walls (blackbody assumption). The proposed model has been integrated into a building simulation code and is based on simple examples; it is shown that intermediate results between the imprecise initial simple model and the more precise detailed model, the net-radiosity method, can be obtained. Finally, an application of the model is made for an existing experimental test cell including a radiant barrier insulation product, well used in Reunion Island for thermal insulation of roofs. With an efficacy based on the very low emissivity of their surfaces and the consequent decrease in radiative heat transfer through the wall in which they are included, the proposed simplified model leads to results very close to those of the reference method, the net-radiosity method. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] A simplified model for radiative transfer in building enclosures with low emissivity walls : development and application to radiant barrier insulation [texte imprimé] / Frédéric Miranville, Auteur ; Philippe Lauret, Auteur ; Mario Medina, Auteur . - 2012 . - 13 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 13 p. Mots-clés : Building  Heat  transfer  Radiative  transfer  Roofs  Thermal  insulation  Walls Index. décimale : 621.47 Résumé : This paper deals with a simplified model of radiative heat transfer in building enclosures with low emissivity walls. The approach is based on an existing simplified model, well known and used in building multizone simulation codes, for the long wave exchanges in building enclosures. This method is simply extended to the case of a cavity including a very low emissivity wall, and it is shown that the obtained formalism is similar to the one used in the case of the based model, convenient for enclosures with only black walls (blackbody assumption). The proposed model has been integrated into a building simulation code and is based on simple examples; it is shown that intermediate results between the imprecise initial simple model and the more precise detailed model, the net-radiosity method, can be obtained. Finally, an application of the model is made for an existing experimental test cell including a radiant barrier insulation product, well used in Reunion Island for thermal insulation of roofs. With an efficacy based on the very low emissivity of their surfaces and the consequent decrease in radiative heat transfer through the wall in which they are included, the proposed simplified model leads to results very close to those of the reference method, the net-radiosity method. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Air-sand heat exchanger for high-temperature storage / Shashikant Warerkar in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Titre : Air-sand heat exchanger for high-temperature storage Type de document : texte imprimé Auteurs : Shashikant Warerkar, Auteur ; Stefan Schmitz, Auteur ; Joachim Goettsche, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Furnaces  Heat  exchangers  High-temperature  techniques  Power  generation  economics  Quartz  Sand  Solar  power  Solar  power  stations  Specific  heat  Steel  industry  Thermal  energy  storage  Thermal  stability Index. décimale : 621.47 Résumé : In view of rising energy prices and an increasing share of power generated by renewable energy sources, the importance of energy storage is growing. In the framework of this project, a thermal energy storage concept for solar power towers is being developed, in which quartz sand serves as a storage medium. Sand is suitable due to its properties such as high thermal stability, specific heat capacity, and low-cost availability. Compared with storages based on ceramic bodies, the use of sand promises to reduce costs of energy storage and thus to reduce the costs of electricity generation. In addition, the storage concept could be applicable in the steel industry. The central element of the storage concept is an air-sand heat exchanger, which is presently under development. This paper describes simulation results and measurements of the heat exchanger prototype. It includes sand flow behavior and experience with different porous walls as well as up-scaling options. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Air-sand heat exchanger for high-temperature storage [texte imprimé] / Shashikant Warerkar, Auteur ; Stefan Schmitz, Auteur ; Joachim Goettsche, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Mots-clés : Furnaces  Heat  exchangers  High-temperature  techniques  Power  generation  economics  Quartz  Sand  Solar  power  Solar  power  stations  Specific  heat  Steel  industry  Thermal  energy  storage  Thermal  stability Index. décimale : 621.47 Résumé : In view of rising energy prices and an increasing share of power generated by renewable energy sources, the importance of energy storage is growing. In the framework of this project, a thermal energy storage concept for solar power towers is being developed, in which quartz sand serves as a storage medium. Sand is suitable due to its properties such as high thermal stability, specific heat capacity, and low-cost availability. Compared with storages based on ceramic bodies, the use of sand promises to reduce costs of energy storage and thus to reduce the costs of electricity generation. In addition, the storage concept could be applicable in the steel industry. The central element of the storage concept is an air-sand heat exchanger, which is presently under development. This paper describes simulation results and measurements of the heat exchanger prototype. It includes sand flow behavior and experience with different porous walls as well as up-scaling options. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Solar gasification of biomass / Brandon J. Hathaway in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 09 p. Titre : Solar gasification of biomass : kinetics of pyrolysis and steam gasification in molten salt Type de document : texte imprimé Auteurs : Brandon J. Hathaway, Auteur ; Jane H. Davidson, Auteur ; David B. Kittelson, Auteur Année de publication : 2012 Article en page(s) : 09 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Electric  furnaces  Fuel  gasification  Heat  transfer  Hydrogen  production  Lithium  Mass  transfer  Potassium  Pyrolysis  Reaction  kinetics  Sodium  Solar  energy  conversion  Stability Index. décimale : 621.47 Résumé : The use of concentrated solar energy as a heat source for pyrolysis and gasification of biomass is an efficient means for production of hydrogen rich synthesis gas. Utilizing molten alkali carbonate salts as a reaction and heat transfer media promises enhanced stability to solar transients and faster reaction rates. The present study establishes and compares the reaction kinetics of pyrolysis and gasification of cellulose from 1124 K to 1235 K in an electric furnace. Data are presented in an inert environment and in a bath of a ternary eutectic blend of lithium, potassium, and sodium carbonate salts. Arrhenius rate expressions are derived from the data supported by a numerical model of heat and mass transfer. The molten salt increases the rate of pyrolysis by 74% and increases gasification rates by more than an order of magnitude while promoting a product gas composition nearer to thermodynamic equilibrium predictions. These results justify using molten carbonate salts as a combined catalyst and heat transfer media for solar gasification. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Solar gasification of biomass : kinetics of pyrolysis and steam gasification in molten salt [texte imprimé] / Brandon J. Hathaway, Auteur ; Jane H. Davidson, Auteur ; David B. Kittelson, Auteur . - 2012 . - 09 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 09 p. Mots-clés : Electric  furnaces  Fuel  gasification  Heat  transfer  Hydrogen  production  Lithium  Mass  transfer  Potassium  Pyrolysis  Reaction  kinetics  Sodium  Solar  energy  conversion  Stability Index. décimale : 621.47 Résumé : The use of concentrated solar energy as a heat source for pyrolysis and gasification of biomass is an efficient means for production of hydrogen rich synthesis gas. Utilizing molten alkali carbonate salts as a reaction and heat transfer media promises enhanced stability to solar transients and faster reaction rates. The present study establishes and compares the reaction kinetics of pyrolysis and gasification of cellulose from 1124 K to 1235 K in an electric furnace. Data are presented in an inert environment and in a bath of a ternary eutectic blend of lithium, potassium, and sodium carbonate salts. Arrhenius rate expressions are derived from the data supported by a numerical model of heat and mass transfer. The molten salt increases the rate of pyrolysis by 74% and increases gasification rates by more than an order of magnitude while promoting a product gas composition nearer to thermodynamic equilibrium predictions. These results justify using molten carbonate salts as a combined catalyst and heat transfer media for solar gasification. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Passive and active thermographic assessment as a tool for condition-based performance monitoring of photovoltaic modules / J. A. Tsanakas in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 06 p. Titre : Passive and active thermographic assessment as a tool for condition-based performance monitoring of photovoltaic modules Type de document : texte imprimé Auteurs : J. A. Tsanakas, Auteur ; P. N. Botsaris, Auteur Année de publication : 2012 Article en page(s) : 06 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Condition  monitoring  Infrared  imaging  Performance  evaluation  Photovoltaic  power  systems  Solar  cells Index. décimale : 621.47 Résumé : Today, to ensure efficient operation of a photovoltaic (PV) system renders as an undoubtedly major concern. Toward this direction, scope of this work is the assessment of infrared thermography as a PV module's condition monitoring and, subsequently, performance evaluation method. The idea is based on the fact that any abnormality to the temperature pattern of an under inspection equipment implies a dysfunction case. In particular, specific thermographic measurements were applied to a PV module with known, abnormally low performance. Following the basic processing of the acquired thermal images, the extracted temperature data were contrasted with the PV module's expected operating temperature. The results validated the presence of a problematic solar cell that refers to a “hot spot” within the tested PV module. This paper concludes with a discussion regarding the advantages, the limitations, and, ultimately, the potentiality of the intended approaches as reliable condition monitoring method through performance evaluation of PV modules. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Passive and active thermographic assessment as a tool for condition-based performance monitoring of photovoltaic modules [texte imprimé] / J. A. Tsanakas, Auteur ; P. N. Botsaris, Auteur . - 2012 . - 06 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 06 p. Mots-clés : Condition  monitoring  Infrared  imaging  Performance  evaluation  Photovoltaic  power  systems  Solar  cells Index. décimale : 621.47 Résumé : Today, to ensure efficient operation of a photovoltaic (PV) system renders as an undoubtedly major concern. Toward this direction, scope of this work is the assessment of infrared thermography as a PV module's condition monitoring and, subsequently, performance evaluation method. The idea is based on the fact that any abnormality to the temperature pattern of an under inspection equipment implies a dysfunction case. In particular, specific thermographic measurements were applied to a PV module with known, abnormally low performance. Following the basic processing of the acquired thermal images, the extracted temperature data were contrasted with the PV module's expected operating temperature. The results validated the presence of a problematic solar cell that refers to a “hot spot” within the tested PV module. This paper concludes with a discussion regarding the advantages, the limitations, and, ultimately, the potentiality of the intended approaches as reliable condition monitoring method through performance evaluation of PV modules. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Spatially varying extinction coefficient for direct absorption solar thermal collector optimization / Todd P. Otanicar in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Titre : Spatially varying extinction coefficient for direct absorption solar thermal collector optimization Type de document : texte imprimé Auteurs : Todd P. Otanicar, Auteur ; Patrick E. Phelan, Auteur ; Robert A. Taylor, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Solar  absorber-convertors  Solar  energy  conversion Index. décimale : 621.47 Résumé : Direct absorption solar thermal collectors have recently been shown to be a promising technology for photothermal energy conversion but many parameters affecting the overall performance of such systems have not been studied in depth, yet alone optimized. Earlier work has shown that the overall magnitude of the extinction coefficient can play a drastic role, with too high of an extinction coefficient actually reducing the efficiency. This study investigates how the extinction coefficient impacts the collector efficiency and how it can be tuned spatially to optimize the efficiency, and why this presents a unique design over conventional solar thermal collection systems. Three specific extinction profiles are investigated: uniform, linearly increasing, and exponentially increasing with the exponentially increasing profile demonstrating the largest efficiency improvement. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Spatially varying extinction coefficient for direct absorption solar thermal collector optimization [texte imprimé] / Todd P. Otanicar, Auteur ; Patrick E. Phelan, Auteur ; Robert A. Taylor, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Mots-clés : Solar  absorber-convertors  Solar  energy  conversion Index. décimale : 621.47 Résumé : Direct absorption solar thermal collectors have recently been shown to be a promising technology for photothermal energy conversion but many parameters affecting the overall performance of such systems have not been studied in depth, yet alone optimized. Earlier work has shown that the overall magnitude of the extinction coefficient can play a drastic role, with too high of an extinction coefficient actually reducing the efficiency. This study investigates how the extinction coefficient impacts the collector efficiency and how it can be tuned spatially to optimize the efficiency, and why this presents a unique design over conventional solar thermal collection systems. Three specific extinction profiles are investigated: uniform, linearly increasing, and exponentially increasing with the exponentially increasing profile demonstrating the largest efficiency improvement. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Solar radiation on horizontal tubular microalgae photobioreactor / T. Maor in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 05 p. Titre : Solar radiation on horizontal tubular microalgae photobioreactor : direct beam radiation Type de document : texte imprimé Auteurs : T. Maor, Auteur ; J. Appelbaum, Auteur Année de publication : 2012 Article en page(s) : 05 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Biofuel  Bioreactors  Microorganisms  Solar  radiation Index. décimale : 621.47 Résumé : The solar irradiation on a photobioreactor plant for cultivating microalgae products such as dyes, vitamin, and biofuel is formulated, calculated, and verified. The outdoor solar plant consists of multiple horizontal tubes arranged in multiple vertical walls. The solar irradiation determines the growth rate of the algae; therefore, calculating the amount of solar radiation on the plant is important to estimate the production of microalgae. The incident direct beam irradiation on the tubes is calculated, taking into account tube and wall shading. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Solar radiation on horizontal tubular microalgae photobioreactor : direct beam radiation [texte imprimé] / T. Maor, Auteur ; J. Appelbaum, Auteur . - 2012 . - 05 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 05 p. Mots-clés : Biofuel  Bioreactors  Microorganisms  Solar  radiation Index. décimale : 621.47 Résumé : The solar irradiation on a photobioreactor plant for cultivating microalgae products such as dyes, vitamin, and biofuel is formulated, calculated, and verified. The outdoor solar plant consists of multiple horizontal tubes arranged in multiple vertical walls. The solar irradiation determines the growth rate of the algae; therefore, calculating the amount of solar radiation on the plant is important to estimate the production of microalgae. The incident direct beam irradiation on the tubes is calculated, taking into account tube and wall shading. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

Horizontal tubular microalgae photobioreactor plant view factors and diffuse radiation / T. Maor in Transactions of the ASME. Journal of solar energy engineering, Vol. 133 N° 2 (Mai 2011) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Titre : Horizontal tubular microalgae photobioreactor plant view factors and diffuse radiation Type de document : texte imprimé Auteurs : T. Maor, Auteur ; J. Appelbaum, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : Solar energy Langues : Anglais (eng) Mots-clés : Biofuel  Bioreactors  Solar  radiation Index. décimale : 621.47 Résumé : Different view factors and different components of the diffuse solar radiation impinging on a photobioreactor plant for cultivating microalgae products are formulated and calculated in the present article. The outdoor plant consists of multiple horizontal tubes arranged in multiple vertical walls. The diffuse radiation on a tube may come from three directions of the sky: from the aperture between the walls (from the sky above), from the penetration of the diffuse radiation between the tubes, and from the plant edges. Each component of the diffuse radiation is associated with a different view factor. For design parameters of a practical plant, the largest component of the diffuse radiation comes from the sky above the plant. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...] [article] Horizontal tubular microalgae photobioreactor plant view factors and diffuse radiation [texte imprimé] / T. Maor, Auteur ; J. Appelbaum, Auteur . - 2012 . - 07 p. Solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 133 N° 2 (Mai 2011) . - 07 p. Mots-clés : Biofuel  Bioreactors  Solar  radiation Index. décimale : 621.47 Résumé : Different view factors and different components of the diffuse solar radiation impinging on a photobioreactor plant for cultivating microalgae products are formulated and calculated in the present article. The outdoor plant consists of multiple horizontal tubes arranged in multiple vertical walls. The diffuse radiation on a tube may come from three directions of the sky: from the aperture between the walls (from the sky above), from the penetration of the diffuse radiation between the tubes, and from the plant edges. Each component of the diffuse radiation is associated with a different view factor. For design parameters of a practical plant, the largest component of the diffuse radiation comes from the sky above the plant. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000133000002 [...]

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