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An air-based cavity-receiver for solar trough concentrators / Bartelt, Roman in Transactions of the ASME. Journal of solar energy engineering, Vol. 132 N° 3 (Août 2010) 

Public ISBD [article]  in Transactions of the ASME. Journal of solar energy engineering > Vol. 132 N° 3 (Août 2010) . - pp. [031017/1-7] Titre : An air-based cavity-receiver for solar trough concentrators Type de document : texte imprimé Auteurs : Bartelt, Roman, Auteur ; Maurizio Barbato, Auteur ; Andrea Pedretti, Auteur Année de publication : 2011 Article en page(s) : pp. [031017/1-7] Note générale : Energie Solaire Langues : Anglais (eng) Mots-clés : Cavity  resonators  Convection  Heat  conduction  Heat  transfer  Monte  Carlo  methods  Solar  absorber-convertors  Solar  radiation Index. décimale : 621.47 Résumé : A cylindrical cavity-receiver containing a tubular absorber that uses air as the heat transfer fluid is proposed for a novel solar trough concentrator design. A numerical heat transfer model is developed to determine the receiver's absorption efficiency and pumping power requirement. The 2D steady-state energy conservation equation coupling radiation, convection, and conduction heat transfer is formulated and solved numerically by finite volume techniques. The Monte Carlo ray-tracing and radiosity methods are applied to establish the solar radiation distribution and radiative exchange within the receiver. Simulations were conducted for a 50 m-long and 9.5 m-wide collector section with 120°C air inlet temperature, and air mass flows in the range 0.1–1.2 kg/s. Outlet air temperatures ranged from 260°C to 601°C, and corresponding absorption efficiencies varied between 60% and 18%. Main heat losses integrated over the receiver length were due to reflection and spillage at the receiver's windowed aperture, amounting to 13% and 9% of the solar power input, respectively. The pressure drop along the 50 m module was in the range 0.23–11.84 mbars, resulting in isentropic pumping power requirements of 6.45×10−4−0.395% of the solar power input. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO00013200 [...] [article] An air-based cavity-receiver for solar trough concentrators [texte imprimé] / Bartelt, Roman, Auteur ; Maurizio Barbato, Auteur ; Andrea Pedretti, Auteur . - 2011 . - pp. [031017/1-7]. Energie Solaire Langues : Anglais (eng) in Transactions of the ASME. Journal of solar energy engineering > Vol. 132 N° 3 (Août 2010) . - pp. [031017/1-7] Mots-clés : Cavity  resonators  Convection  Heat  conduction  Heat  transfer  Monte  Carlo  methods  Solar  absorber-convertors  Solar  radiation Index. décimale : 621.47 Résumé : A cylindrical cavity-receiver containing a tubular absorber that uses air as the heat transfer fluid is proposed for a novel solar trough concentrator design. A numerical heat transfer model is developed to determine the receiver's absorption efficiency and pumping power requirement. The 2D steady-state energy conservation equation coupling radiation, convection, and conduction heat transfer is formulated and solved numerically by finite volume techniques. The Monte Carlo ray-tracing and radiosity methods are applied to establish the solar radiation distribution and radiative exchange within the receiver. Simulations were conducted for a 50 m-long and 9.5 m-wide collector section with 120°C air inlet temperature, and air mass flows in the range 0.1–1.2 kg/s. Outlet air temperatures ranged from 260°C to 601°C, and corresponding absorption efficiencies varied between 60% and 18%. Main heat losses integrated over the receiver length were due to reflection and spillage at the receiver's windowed aperture, amounting to 13% and 9% of the solar power input, respectively. The pressure drop along the 50 m module was in the range 0.23–11.84 mbars, resulting in isentropic pumping power requirements of 6.45×10−4−0.395% of the solar power input. DEWEY : 621.47 ISSN : 0199-6231 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JSEEDO00013200 [...]

Analysis of single-phase 50-kW 16.7-Hz PI-controlled four-quadrant line-side converter under different grid characteristics / Heising, Carsten in IEEE transactions on industrial electronics, Vol. 57 N° 2 (Fevrier 2010) 

Public ISBD [article]  in IEEE transactions on industrial electronics > Vol. 57 N° 2 (Fevrier 2010) . - pp. 523 - 531 Titre : Analysis of single-phase 50-kW 16.7-Hz PI-controlled four-quadrant line-side converter under different grid characteristics Type de document : texte imprimé Auteurs : Heising, Carsten, Auteur ; Bartelt, Roman, Auteur ; Oettmeier, Martin, Auteur Article en page(s) : pp. 523 - 531 Note générale : Génie électrique Langues : Anglais (eng) Mots-clés : AC-AC  power  conversion  Rail  transportation  propulsion  Traction  motor  drives Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : Four-quadrant line-side converters supplying pulsewidth-modulation (PWM)-inverter-fed induction machines are a standard application in ac railway traction vehicles. In the scope of an extensive project aiming at an advanced overall control scheme for traction vehicles taking, among others, grid interaction and stability into account, the steady-state and transient operations of a single-phase 50-kW 16.7-Hz four-quadrant line-side converter is analyzed in detail. The converter is fed either by an inverter or via a slip-ring induction generator with dc excitation, operating as railway-grid rotary-converter representation. In this paper, the structure of the 50-kW test bench, representing a railway grid and a traction vehicle, the applied simulation concept, and the personal-computer-based real-time control hardware used are introduced. Measurement results for sinusoidal as well as highly disturbed line voltage verify the proper operation of the line-side converter, whose proportional-integral control scheme is described in detail. Two different loads are used: switched resistor and motor PWM inverter. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5256222 [article] Analysis of single-phase 50-kW 16.7-Hz PI-controlled four-quadrant line-side converter under different grid characteristics [texte imprimé] / Heising, Carsten, Auteur ; Bartelt, Roman, Auteur ; Oettmeier, Martin, Auteur . - pp. 523 - 531. Génie électrique Langues : Anglais (eng) in IEEE transactions on industrial electronics > Vol. 57 N° 2 (Fevrier 2010) . - pp. 523 - 531 Mots-clés : AC-AC  power  conversion  Rail  transportation  propulsion  Traction  motor  drives Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : Four-quadrant line-side converters supplying pulsewidth-modulation (PWM)-inverter-fed induction machines are a standard application in ac railway traction vehicles. In the scope of an extensive project aiming at an advanced overall control scheme for traction vehicles taking, among others, grid interaction and stability into account, the steady-state and transient operations of a single-phase 50-kW 16.7-Hz four-quadrant line-side converter is analyzed in detail. The converter is fed either by an inverter or via a slip-ring induction generator with dc excitation, operating as railway-grid rotary-converter representation. In this paper, the structure of the 50-kW test bench, representing a railway grid and a traction vehicle, the applied simulation concept, and the personal-computer-based real-time control hardware used are introduced. Measurement results for sinusoidal as well as highly disturbed line voltage verify the proper operation of the line-side converter, whose proportional-integral control scheme is described in detail. Two different loads are used: switched resistor and motor PWM inverter. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5256222