Exergoeconomic and exergoenvironmental analyses of an integrated SOFC-GT-ORC hybrid system

Abstract

In this study, an optimal design and analysis of an integrated internal reforming Solid Oxide fuel cell (IRSOFC) - Gas Turbine (GT) - Organic Rankine Cycle (ORC) system are investigated. R407C and R404A as ORC working fluids are used to produce the additional power based on the recovery of the flue gases in the ORC. A thermodynamic simulation of the integrated system has been performed to evaluate the performance of the proposed cycle. In this regard, exergetic, exergoeconomic and exergoenvironmental analyses have been done for a better understanding of the interaction between the components and the overall system. In order to carry out the exergoenvironmental analysis, the environmental impacts obtained by Life Cycle Assessment (LCA) are apportioned to the exergy streams. The analysis of this integrated system has been carried out by using computer code in MATLAB. A Multi-Objective Water Cycle Algorithm based on the maximization of overall exergy efficiency and minimization of total exergetic cost rate and total exergetic environmental impacts was performed to find optimum design variables for the proposed system. The results show that R407C has the best thermodynamic performance and with this organic fluid the overall energy and exergy efficiencies for the proposed optimum system are 49.42% and 46.83% respectively. Furthermore, the exergoeconomic and exergoenvironmental main optimum parameters are comprised and evaluated.