Selection of The Optimal Working Fluid in an Organic Rankine Cycle for Waste Heat Recovery Through Multi-Objective Optimization and Decision Making

Abstract

In India, utilising low-temperature waste heat is crucial to improving energy efficiency. The regenerative organic Rankine cycle (ORC) process is a promising waste heat recovery technique in this study. Here, the thermodynamic behaviour of eight working fluids: Butane, Heptane, Hexane, Pentane, Cyclopentane, HexMDiSiloxn (MM), Benzene, and Toluene, was carefully examined. An elite Nondominated sorting genetic sorting algorithm (NSGA-II) was used in Multi-objective Optimization (MOO) to address the incongruent behaviour of thermodynamic performance (exergy efficiency) and economic performance (levelized energy cost, LEC). Every eight working fluids are the subject of MOO studies, and the resulting Pareto optimal fronts are created. Several advanced Pareto ranking techniques are taken into account to choose one ideal solution from the Pareto optimal front. These include Simple additive weighting (SAW), The technique for order of preference by similarity to deal Solution (TOPSIS), Grey relation analysis (GRA), and Multi-attributive border approximation area comparison (MABAC). The most economically advantageous working fluid is chosen using an explicit economic performance assessment index called the Static Investment Payback Period (SIPP). The results show that Pentane is the most economically advantageous working fluid with the shortest SIPP and a medium waste heat temperature range. The findings also imply that any working fluid can be used TOPSIS, SAW, GRA, and MABAC with entropy information considered in this study to recover low-temperature waste heat in the ORC.