Proposal of a combined heat and power plant hybridized with regeneration organic Rankine cycle: Energy-Exergy evaluation Simin Anvari, Samad Jafarmadar ⇑ , Shahram Khalilarya Mechanical Engineering Department, Technical Education Faculty, Urmia University, Urmia, West Azerbaijan 57561-15311, Iran article info Article history: Received 11 January 2016 Received in revised form 26 May 2016 Accepted 1 June 2016 Keywords: Cogeneration cycle Regeneration Rankine cycle Exergy analysis Exergy efficiency abstract Among Rankine cycles (simple, reheat and regeneration), regeneration organic Rankine cycle demon- strates higher efficiencies compared to other cases. Consequently, in the present work a regeneration organic Rankine cycle has been utilized to recuperate gas turbine’s heat using heat recovery steam gen- erator. At first, this cogeneration system was subjected to energy and exergy analysis and the obtained results were compared with that of investigated cogeneration found in literature (a cogeneration system in which a reheat organic Rankine cycle for heat recuperation of gas turbine cycle was used with the aid of heat recovery steam generator). Results indicated that the first and second thermodynamic efficiencies in present cycle utilizing regeneration cycle instead of reheat cycle has increased 2.62% and 2.6%, respec- tively. In addition, the effect of thermodynamic parameters such as combustion chamber’s inlet temper- ature, gas turbine inlet temperature, evaporator and condenser temperature on the energetic and exergetic efficiencies of gas turbine-heat recovery steam generator cycle and gas turbine-heat recovery steam generator cycle with regeneration organic Rankine cycle was surveyed. Besides, parametric anal- ysis shows that as gas turbine and combustion chamber inlet temperatures increase, energetic and exer- getic efficiencies tend to increase. Moreover, once condenser and evaporator temperature raise, a slight decrement in energetic and exergetic efficiency is expected. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction Energy has a key role in economic and social development, also energy saving gains more and more merit to explore and delve into facing rapid industrial growth which necessitates a great deal of energy input. The exhaustion of fossil fuel reservoir as the largest resource of energy and escalating environmental concerns, have convinced the man to come up with new utilization methods for optimal use of energy. Due to their more efficient power output, the combined power plants succeeded receiving more reception than their conventional counterparts worldwide [1]. The combined cycles for instance cogeneration (also known as Combined Heat and Power, CHP) units can give simultaneous output of heat and power from a joint energy source. Since acquired results from recent investigations on Organic Rankine Cycle (ORC) is indicative of its great potential to convert low-temperature thermal sources into power, this system is considered as a high-tech device in [2]. By virtue of ORCs have the ability to use low-scale energy in variety of thermodynamic systems, they have been extensively adopted within the last two decades, Vaja and Gambarotta [3] applied the exhaust gases of Internal Combustion Engine (ICE) in the Rankine cycle and made 12% increase in the system efficiency. Kosmadakis and et al. [4] addressed the parametric study of a two-stage solar Rankine cycle for making RO desalination. Many studies have investigated the ORC performances as well: Wang et al. [5] reported that employment of the organic Rankine cycle in cement production yield the save of energy and reduction of the gas emis- sions. Feidt et al. [6] performed the optimum performance of organic Rankine cycles with low-GWP (global warming potential) organic compounds as working fluid. Feng et al. [7] carried out a sensitivity analysis and an exergoeconomic comparison for the low heat organic Rankine cycles. Some works have been imple- mented to couple ORC to gasoline engines by Wang et al. [8]. Zhang et al. [9] included a finned-tube evaporator to recuperate loss heat from engine. Following, Zhu et al. [10] examined the exergy destruction and exergy flow map of a bottoming ORC to recycle waste heat of the engine exhaust outlet. Furthermore, the exergy destruction in each segment and the exergy efficiency of the ORC system were addressed by Kaska [11]. Vatani et al. [12] used an ORC with two different configurations to recover heat from a proposed Direct Internal Reforming Molten Carbonate Fuel Cell (DIR-MCFC). They reported that the overall exergy efficiency is obtained to be 54.75%. Wang et al. [13] employed the http://dx.doi.org/10.1016/j.enconman.2016.06.002 0196-8904/Ó 2016 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: S.jafarmadar@urmia.ac.ir (S. Jafarmadar). Energy Conversion and Management 122 (2016) 357–365 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman