Exergy Assessment of Recovery Solutions from Dry and Moist Gas Available at Medium Temperature

Energies

Fadhel Ayachi¹  Elias Boulawz Ksayer² 

[1] PROMES (PROcédés, Matériaux et Energie Solaire)—CNRS (Centre National de la Recherche Scientifique), Tecnosud Rambla de la thermodynamique, Perpignan 66100, France;CEP MINES Paris-Tech (Centre Energétique et Procédés), 5 rue Léon Blum, Palaiseau 91120, France; E-Mail:

关键词: thermodynamic optimization;    exergy;    pinch;    ORC;    subcritical cycles;    transcritical cycles;    cascade;   

DOI  :  10.3390/en5030718

来源: mdpi

【 摘 要 】

The Agence Nationale de la Recherche (ANR-EESI) ENERGY ReCOvery from Low Temperature heat sources (ENERCO_LT) project is a waste heat recovery project that aims to reduce energy consumption in industrial gas production sites, by producing electrical power from exothermic processes discharges at low and medium temperature. Two promising thermal sources, consisting of: (i) almost dry gas flow at 165 °C and (ii) moist gas flow at 150 °C with a dew point at 60 °C, were then investigated. In this paper, the challenge was to discern suitable recovery solutions facing resource specificities and their thermodynamic constraints, in order to minimize the overall exergy destruction, i.e., to move up the exergy efficiency of the entire system. In this spirit, different designs, including Organic Rankine Cycles (ORCs) and CO₂ transcritical cycles, operating as simple and cascade cycles, were investigated. Combined exergy analysis and pinch optimization was performed to identify the potential of various working fluids, by their properties, to overcome the global irreversibility according to the studied resource. Supercritical parameters of various working fluids are investigated too, and seem to bring promising results regarding system performances.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.