Eur. Phys. J. Appl. Phys. (2017) 78: 34808 DOI: 10.1051/epjap/2017170088 THE EUROPEAN PHYSICAL JOURNAL APPLIED PHYSICS Regular Article Analysis and optimization of three main organic Rankine cycle configurations using a set of working fluids with different thermodynamic behaviors ⋆ Basma Hamdi 1, a , Mohamed Tahar Mabrouk 2 , Lakdar Kairouani 1 , and Abdelhamid Kheiri 2 1 Unit´ e de Recherche ´ Energ´ etique et Environnement, Ecole Nationale d’Ing´ enieurs de Tunis, Univerist´ e de Tunis El Manar, BP 37 Le Belv´ ed` ere 1002 Tunis, Tunisie 2 LEMTA, UMR CNRS 7563, Universit´ e de Lorraine, 2 avenue de la Forˆ et de Haye, 54500 Vandœuvre-l` es-Nancy, France Received: 6 March 2017 / Received in final form: 4 May 2017 / Accepted: 9 May 2017 c  EDP Sciences 2017 Abstract. Different configurations of organic Rankine cycle (ORC) systems are potential thermodynamic concepts for power generation from low grade heat. The aim of this work is to investigate and optimize the performances of the three main ORC systems configurations: basic ORC, ORC with internal heat exchange (IHE) and regenerative ORC. The evaluation for those configurations was performed using seven working fluids with typical different thermodynamic behaviours (R245fa, R601a, R600a, R227ea, R134a, R1234ze and R1234yf). The optimization has been performed using a genetic algorithm under a comprehensive set of operative parameters such as the fluid evaporating temperature, the fraction of flow rate or the pressure at the steam extracting point in the turbine. Results show that there is no general best ORC configuration for all those fluids. However, there is a suitable configuration for each fluid. Nomenclature C p Specific heat, kJ kg -1 K -1 e Exergy for each point x ˙ E Exergy received by the working fluid at any point h Specific enthalpy, kJ kg -1 ˙ m Mass flow rate, kg s -1 M Molar mass, g/mol P Pressure, MPa ˙ Q Heat flow rate, kW s Specific entropy, kJ kg -1 K -1 T Temperature, K W Power, kW Greek symbols η Efficiency ε Efficacy of IHE Subscripts b Boiling point cri Critical point a e-mail: bsm.hamdi09@gmail.com ⋆ Contribution to the topical issue “Materials for Energy harvesting, conversion and storage II (ICOME 2016)”, edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui c Heat sink c Condenser e Evaporator GWP Global warming potential in Inlet h Heat source ODP Ozone depletion potential IHE Internal heat exchange out Outlet OFH Organic feed heater p Pump reg Regenerative wf Working fluid 1 Introduction Great efforts are needed nowadays in order to reduce the greenhouse gas emission to prevent global warming and the climate change. Developing efficient technologies for renewable energy sources such as solar energy, biomass and geothermal ground heat is an essential step to attain important cuts in CO 2 emissions. This should be coupled with a substantial enhancement of the efficiency of exist- ing facilities. In this landscape, the organic Rankine cycle (ORC) system seems to be a suitable technology to con- vert heat at medium/low temperature to electricity. However, more efforts must be made to improve its own efficiency particularly by careful selection of the best work- ing fluids that matches the heat source. In the same time, 34808-p1