Documents disponibles écrits par cet auteur

Highly efficient IGFC hybrid power systems employing bottoming organic rankine cycles with optional carbon capture / R. J. Braun in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 134 N° 2 (Février 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 2 (Février 2012) . - 15 p. Titre : Highly efficient IGFC hybrid power systems employing bottoming organic rankine cycles with optional carbon capture Type de document : texte imprimé Auteurs : R. J. Braun, Auteur ; S. Kameswaran, Auteur ; J. Yamanis, Auteur ; E. Sun, Auteur Année de publication : 2012 Article en page(s) : 15 p. Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Climate  mitigation  Coal  gasification  Fuel  cell  power  plants  Gas  turbines  Hybrid  power  systems  Oxygen  Solid  oxide  fuel  cells  Syngas Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This study examines the performance of a solid oxide fuel cell- (SOFC-) based integrated gasification power plant concept at the utility scale (>100 MW). The primary system concept evaluated was a pressurized ~150 MW SOFC hybrid power system integrated with an entrained-flow, dry-fed, oxygen-blown, slagging coal gasifier and a combined cycle in the form of a gas turbine and an organic Rankine cycle (ORC) power generator. The analyzed concepts include carbon capture via oxy-combustion followed by water knockout and gas compression to pipeline-ready CO2 sequestration conditions. The results of the study indicate that hybrid SOFC systems could achieve electric efficiencies approaching 66% [lower heating value (LHV)] when operating fueled by coal-derived clean syngas and without carbon dioxide capture. The system concept integrates SOFCs with the low-pressure turbine spool of a 50 MW Pratt & Whitney FT8-3 TwinPak gas turbine set and a scaled-up, water-cooled 20 MW version of the Pratt & Whitney (P&W) PureCycle ORC product line (approximately 260 kW). It was also found that a system efficiency performance of about 48% (LHV) is obtained when the system includes entrained-flow gasifier and carbon capture using oxygen combustion. In order to integrate the P&W FT8 into the SOFC system, the high-pressure turbine spool is removed which substantially lowers the FT8 capital cost and increases the expected life of the gas turbine engine. The impact of integrating an ORC bottoming cycle was found to be significant and can add as much as 8 percentage points of efficiency to the system. For sake of comparison, the performance of a higher temperature P&W ORC power system was also investigated. Use of a steam power cycle, in lieu of an ORC, could increase net plant efficiency by another 4%, however, operating costs are potentially much lower with ORCs than steam power cycles. Additionally, the use of cathode gas recycle is strongly relevant to efficiency performance when integrating with bottoming cycles. A parameter sensitivity analysis of the system revealed that SOFC power density is strongly influenced by design cell voltage, fuel utilization, and amount of anode recycle. To maximize the power output of the modified FT8, SOFC fuel utilization should be lower than 70%. Cathode side design parameters, such as pressure drop and temperature rise were observed to only mildly affect efficiency and power density. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000002 [...] [article] Highly efficient IGFC hybrid power systems employing bottoming organic rankine cycles with optional carbon capture [texte imprimé] / R. J. Braun, Auteur ; S. Kameswaran, Auteur ; J. Yamanis, Auteur ; E. Sun, Auteur . - 2012 . - 15 p. Génie mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 134 N° 2 (Février 2012) . - 15 p. Mots-clés : Climate  mitigation  Coal  gasification  Fuel  cell  power  plants  Gas  turbines  Hybrid  power  systems  Oxygen  Solid  oxide  fuel  cells  Syngas Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This study examines the performance of a solid oxide fuel cell- (SOFC-) based integrated gasification power plant concept at the utility scale (>100 MW). The primary system concept evaluated was a pressurized ~150 MW SOFC hybrid power system integrated with an entrained-flow, dry-fed, oxygen-blown, slagging coal gasifier and a combined cycle in the form of a gas turbine and an organic Rankine cycle (ORC) power generator. The analyzed concepts include carbon capture via oxy-combustion followed by water knockout and gas compression to pipeline-ready CO2 sequestration conditions. The results of the study indicate that hybrid SOFC systems could achieve electric efficiencies approaching 66% [lower heating value (LHV)] when operating fueled by coal-derived clean syngas and without carbon dioxide capture. The system concept integrates SOFCs with the low-pressure turbine spool of a 50 MW Pratt & Whitney FT8-3 TwinPak gas turbine set and a scaled-up, water-cooled 20 MW version of the Pratt & Whitney (P&W) PureCycle ORC product line (approximately 260 kW). It was also found that a system efficiency performance of about 48% (LHV) is obtained when the system includes entrained-flow gasifier and carbon capture using oxygen combustion. In order to integrate the P&W FT8 into the SOFC system, the high-pressure turbine spool is removed which substantially lowers the FT8 capital cost and increases the expected life of the gas turbine engine. The impact of integrating an ORC bottoming cycle was found to be significant and can add as much as 8 percentage points of efficiency to the system. For sake of comparison, the performance of a higher temperature P&W ORC power system was also investigated. Use of a steam power cycle, in lieu of an ORC, could increase net plant efficiency by another 4%, however, operating costs are potentially much lower with ORCs than steam power cycles. Additionally, the use of cathode gas recycle is strongly relevant to efficiency performance when integrating with bottoming cycles. A parameter sensitivity analysis of the system revealed that SOFC power density is strongly influenced by design cell voltage, fuel utilization, and amount of anode recycle. To maximize the power output of the modified FT8, SOFC fuel utilization should be lower than 70%. Cathode side design parameters, such as pressure drop and temperature rise were observed to only mildly affect efficiency and power density. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000134000002 [...]