Simulation and exergy evaluation of a MED unit based on waste heat recovery from a gas turbine unit


1 Department of Mechanical Engineering, Kermanshah University of Technology, Kermanshah, Iran

2 Department of Mechanical Engineering, Faculty of Technology, Isparta University of Applied Sciences, Isparta, 32200, Turkey

3 Department of Environmental Energy Engineering, Kyonggi University, Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16227, South Korea



Integrating MED-TVC unit with gas turbine cycle (GTC) and organic Rankine cycle (ORC) can be an effective way to take advantage of the hot exhaust gas of gas turbines. In this study, a multi-product system consisting of GTC, MED-TVC, and ORC is investigated. The energy and exergy analysis is carried out and influences some design variables such as inlet air temperature of air compressor, air compressor pressure ratio, high pressure in ORC, pinch point temperature difference, the pressure of motive steam, and TVC compression ratio on the developed system are examined. Calculation shows that the developed unit can produce 39.6 MW of power and 137.3 kg/s of fresh water with a gain output ratio of 4.41 and energy efficiency of 21.5%. According to the result, precooling the air at the entrance of the air compressor and decreasing the pinch point temperature can lead to enhancement exergy and energy efficiency of GTC and the gain output ratio of MED unit, respectively. In addition, the highest exergy destruction takes place in the combustion chamber and desalination unit.


[1] Ka┼čka Ö. Energy and exergy analysis of an organic Rankine for power generation from waste heat recovery in steel industry. Energy Convers Manag 2014;77:108–17. doi:10.1016/J.ENCONMAN.2013.09.026.
[2] Musharavati F, Khanmohammadi S. Design and exergy based optimization of a clean energy system with fuel Cell/MED and hydrogen storage option. Int J Hydrogen Energy 2021. doi:10.1016/j.ijhydene.2021.07.214.
[3] Musharavati F, Khanmohammadi S, Pakseresht A, Khanmohammadi S. Waste heat recovery in an intercooled gas turbine system: Exergo-economic analysis, triple objective optimization, and optimum state selection. J Clean Prod 2021;279:123428. doi:10.1016/j.jclepro.2020.123428.
[4] Singh R, Singh O. Comparative study of combined solid oxide fuel cell-gas turbine-Organic Rankine cycle for different working fluid in bottoming cycle. Energy Convers Manag 2018;171:659–70. doi:10.1016/j.enconman.2018.06.009.
[5] Musharavati F, Khoshnevisan A, Alirahmi SM, Ahmadi P, Khanmohammadi S. Multi-objective optimization of a biomass gasification to generate electricity and desalinated water using Grey Wolf Optimizer and artificial neural network. Chemosphere 2022;287:131980. doi:10.1016/j.chemosphere.2021.131980.
[6] Dastgerdi HR, Whittaker PB, Chua HT. New MED based desalination process for low grade waste heat. Desalination 2016;395:57–71. doi:10.1016/j.desal.2016.05.022.
[7] Maheswari KS, Kalidasa Murugavel K, Esakkimuthu G. Thermal desalination using diesel engine exhaust waste heat — An experimental analysis. Desalination 2015;358:94–100. doi:10.1016/J.DESAL.2014.12.023.
[8] Kim YM, Sohn JL, Yoon ES. Supercritical CO2 Rankine cycles for waste heat recovery from gas turbine. Energy 2017;118:893–905. doi:10.1016/J.ENERGY.2016.10.106.
[9] Valero A, Lozano MA, Serra L, Tsatsaronis G, Pisa J, Frangopoulos C, et al. CGAM problem: Definition and conventional solution. Energy 1994;19:279–86. doi:10.1016/0360-5442(94)90112-0.
[10] Fundamentals of Salt Water Desalination. Elsevier; 2002. doi:10.1016/B978-0-444-50810-2.X5000-3.
[11] Gholamian E, Ahmadi P, Hanafizadeh P, Mazzarella L. The use of waste heat recovery (WHR) options to produce electricity, heating, cooling, and freshwater for residential buildings. Energy Equip Syst 2020;8:277–96. doi:10.22059/EES.2020.44949.
[12] Ameri M, Ahmadi P, Khanmohammadi S. Exergy analysis of a 420 MW combined cycle power plant. Int J Energy Res 2008;32:175–83. doi:10.1002/er.1351.
[13] Sharaf MA, Nafey AS, García-Rodríguez L. Thermo-economic analysis of solar thermal power cycles assisted MED-VC (multi effect distillation-vapor compression) desalination processes. Energy 2011;36:2753–64. doi:10.1016/
[14] You H, Han J, Liu Y. Performance assessment of a CCHP and multi-effect desalination system based on GT/ORC with inlet air precooling. Energy 2019;185:286–98. doi:10.1016/
[15] Al-Mutaz IS, Wazeer I. Development of a steady-state mathematical model for MEE-TVC desalination plants. Desalination 2014;351:9–18. doi:10.1016/j.desal. 2014.07.018.