Documents disponibles écrits par cet auteur

Optical analysis of the fixed mirror solar concentrator by forward ray-tracing procedure / Ramon Pujol Nadal in Transactions of the ASME. Journal of solar energy engineering, Vol. 134 N° 3 (Août 2012) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 134 N° 3 (Août 2012) . - 14 p. Titre : Optical analysis of the fixed mirror solar concentrator by forward ray-tracing procedure Type de document : texte imprimé Auteurs : Ramon Pujol Nadal, Auteur ; Víctor Martínez Moll, Auteur Année de publication : 2012 Article en page(s) : 14 p. Note générale : solar energy Langues : Anglais (eng) Mots-clés : FMSC;  IAM;  ray-tracking;  heating  process;  mobile  focus Index. décimale : 621.47 Résumé : The fixed mirror solar concentrator (FMSC) is a mobile focus concentrator whose design emerged in the 1970s in an effort to reduce electricity production costs in solar thermal power plants. This geometry has not yet been analyzed with 3D ray-tracing procedures. The geometry of FMSC is defined using three parameters: the number of mirrors N, the ratio of focal length and reflector width F/W, and the intercept factor gamma (in order to represent different receiver widths). For the analysis, a 3D ray-tracing code that allows the characterization of solar concentrators was developed. A standard evacuated tube was used as a receiver. The geometric concentration ratio, the optical efficiency, and the transversal and longitudinal incidence angle modifier (IAM) curves for different values of design parameters were calculated. High concentrations imply low F/W values and for high efficiencies, large intercept factor values are required. Increasing the F/W ratio has a positive effect on the transversal IAM, yet a negative one for the longitudinal IAM. Increasing the number of mirrors has a negative effect on both IAM curves due to the self-shadowing between the adjacent steps. Increasing the intercept factor only has a significant positive effect on the longitudinal IAM. The goodness of the IAM factorization approach was analyzed, and it was found that it can be used as long as a new correction factor to account for the focus displacement is introduced. The results presented in this paper provide information, in form of curves, regarding the optical behavior of the FMSC in terms of different design parameters in order to know the possibility to use the FMSC in medium range temperature applications. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000003 [...] [article] Optical analysis of the fixed mirror solar concentrator by forward ray-tracing procedure [texte imprimé] / Ramon Pujol Nadal, Auteur ; Víctor Martínez Moll, Auteur . - 2012 . - 14 p. solar energy Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 134 N° 3 (Août 2012) . - 14 p. Mots-clés : FMSC;  IAM;  ray-tracking;  heating  process;  mobile  focus Index. décimale : 621.47 Résumé : The fixed mirror solar concentrator (FMSC) is a mobile focus concentrator whose design emerged in the 1970s in an effort to reduce electricity production costs in solar thermal power plants. This geometry has not yet been analyzed with 3D ray-tracing procedures. The geometry of FMSC is defined using three parameters: the number of mirrors N, the ratio of focal length and reflector width F/W, and the intercept factor gamma (in order to represent different receiver widths). For the analysis, a 3D ray-tracing code that allows the characterization of solar concentrators was developed. A standard evacuated tube was used as a receiver. The geometric concentration ratio, the optical efficiency, and the transversal and longitudinal incidence angle modifier (IAM) curves for different values of design parameters were calculated. High concentrations imply low F/W values and for high efficiencies, large intercept factor values are required. Increasing the F/W ratio has a positive effect on the transversal IAM, yet a negative one for the longitudinal IAM. Increasing the number of mirrors has a negative effect on both IAM curves due to the self-shadowing between the adjacent steps. Increasing the intercept factor only has a significant positive effect on the longitudinal IAM. The goodness of the IAM factorization approach was analyzed, and it was found that it can be used as long as a new correction factor to account for the focus displacement is introduced. The results presented in this paper provide information, in form of curves, regarding the optical behavior of the FMSC in terms of different design parameters in order to know the possibility to use the FMSC in medium range temperature applications. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO000134000003 [...]