6E evaluation of an innovative polygeneration system consisting of gas turbine cycle with CO2 capture, ejector refrigeration cycle, steam Rankine cycle, solar tower and MEDAD unit

Abstract

The development of the energy systems in terms of technical performance and their assessment from an economic and environmental perspective has been a trending subject, lately. Due to global warming, the effectiveness of these systems has decreased. The pre-cooling technology of the incoming air is known as an influential factor to compensate for this limitation. In this study, we aim to provide a fossil fuel-based power generation system along with the solar energy, and upgrade it to a poly-generation system with the motivation to create an integrated set to meet the needs of power, cooling, heating, freshwater and CO2. In this framework, an integrated system consisting of gas turbine cycle (GTC) with CO2 capture, steam Rankine cycle (SRC), ejector refrigeration cycle (ERC), solar tower cycle (STC), hybrid multi-effect distillation adsorption desalination (MEDAD) is proposed, which presents a new design of a poly-generation system. The proposed system is modeled as a code in MATLAB to analyze energy, exergy, exergo-economic, exergo-environmental, emergo-economic and emergo-environmental (6E), and the validity of its thermodynamic results is compared with results obtained from simulation in Thermoflex. In addition, a parametric sensitivity analysis is performed that considers increasing the number of MEDAD stages, heating the air output from the air compressor (AC), pre-cooling the air entering AC to achieve the optimal operating conditions of the considered system in order to increase freshwater production, reduce fuel consumption and increase power generation. The results showed that the amount of freshwater produced with the correct use of thermal energy sources increases by 95.25 %, fuel consumption decreases by 22 % and net power of GTC increases by 5 %. Finally, the overall energy efficiency of the system in single generation (power production only) and multiple generation is 34.27 % and 65.65 %, respectively.