Novel combined extended-advanced exergy analysis methodology as a new tool to assess thermodynamic systems

Abstract

In this study, a novel combined extended-advanced exergy analysis method is developed for assessing thermodynamic systems. The method is established by combining extended exergy analysis with advanced exergy analysis and the so-called extended-advanced exergy analysis. The methodology used in the novel analysis method is different from only extended exergy analysis and only advanced exergy analysis, but the criteria are the same to reach the goal. This proposed method is applied to a gas turbine system as a case study to show its variability. The gas turbine system considered consists of a combustion chamber, a compressor and turbine units. The conventional (Fuel-Product approach), advanced and extended exergy analyses are separately applied to the case study system for the comparison with the novel combined extended-advanced exergy analysis. It is seen that the combined extended-advanced exergy analysis results of the case study are not exactly the same with the advanced and extended exergy analyses’ results. The reason for this is its comprehensive joint of various thermodynamic analysis methodologies integrating all materials, capital, labor, energy and environmental effect instead of the relation between components and their improvement potentials in one analysis. But it is assessed that the novel analysis tool is able to apply all of those analyses into one simple methodology. The exergy efficiencies of the case study are 28% and 31% by considering the conventional and extended exergy analyses, respectively. This means that all input parameters including labor, capital and environment are used with better efficiency. Also, the exogenous exergy destruction rate (159 kW) is higher for the combined extended-advanced exergy analysis (384 kW). This shows that the relations between other components are increased for the turbine. Another important change is shown in avoidable exogenous exergy destruction rate for the turbine, increasing from 374 kW to 833 kW. This new combined method is useful to those, who wish to apply advanced and extended exergy analyses through a new practical assessment way.