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Thermodynamic analysis of part-flow cycle supercritical CO2 gas turbines / Motoaki Utamura in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 11 (Novembre 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 11 (Novembre 2010) . - 07 p. Titre : Thermodynamic analysis of part-flow cycle supercritical CO2 gas turbines Type de document : texte imprimé Auteurs : Motoaki Utamura, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Brayton  cycle  Carbon  compounds  Gas  turbines  Heat  exchangers  Heat  transfer Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Cycle characteristics of closed gas turbines using supercritical carbon dioxide as a working fluid are investigated. It is found that an anomalous behavior of the physical properties of CO2 at the pseudocritical point may limit the heat exchange rate of a regenerative heat exchanger due to the presence of a pinch point inside the regenerative heat exchanger. Taking such a pinch problem into consideration, the cycle efficiency of the Brayton cycle is assessed. Its value is found to be limited to 39% degraded by 8% compared with the case without the pinch present inside. As an alternative, a part-flow cycle is investigated and its operable range has been identified. It is revealed that the part-flow cycle is effective to recover heat transfer capability and may achieve the cycle thermal efficiency of 45% under maximum operating conditions of 20 MPa and 800 K. Optimal combination of turbine expansion ratio and a part-flow ratio is 2.5 and 0.68, respectively. Parametric study is carried out. In neither compressor nor turbine, deteriorated adiabatic efficiency may affect cycle efficiency significantly. However, pressure drop characteristics of heat exchangers govern the cycle efficiency. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Thermodynamic analysis of part-flow cycle supercritical CO2 gas turbines [texte imprimé] / Motoaki Utamura, Auteur . - 2011 . - 07 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 11 (Novembre 2010) . - 07 p. Mots-clés : Brayton  cycle  Carbon  compounds  Gas  turbines  Heat  exchangers  Heat  transfer Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Cycle characteristics of closed gas turbines using supercritical carbon dioxide as a working fluid are investigated. It is found that an anomalous behavior of the physical properties of CO2 at the pseudocritical point may limit the heat exchange rate of a regenerative heat exchanger due to the presence of a pinch point inside the regenerative heat exchanger. Taking such a pinch problem into consideration, the cycle efficiency of the Brayton cycle is assessed. Its value is found to be limited to 39% degraded by 8% compared with the case without the pinch present inside. As an alternative, a part-flow cycle is investigated and its operable range has been identified. It is revealed that the part-flow cycle is effective to recover heat transfer capability and may achieve the cycle thermal efficiency of 45% under maximum operating conditions of 20 MPa and 800 K. Optimal combination of turbine expansion ratio and a part-flow ratio is 2.5 and 0.68, respectively. Parametric study is carried out. In neither compressor nor turbine, deteriorated adiabatic efficiency may affect cycle efficiency significantly. However, pressure drop characteristics of heat exchangers govern the cycle efficiency. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]