Exergy based methods for economic and environmental analysis applied to a 320 MW Combined Cycle Power Plant

In the last decades, the growing scarcity of non-renewable resources led analysts and researchers to sharpen Second Law analysis methods in order to understand how to minimize the consumption of natural resources on the part of energy conversion systems. Thermoeconomics demonstrates to be a proper and promising framework to evaluate and optimize exergetic and economic costs of energy systems products. Understanding the relation between the economic cost and its natural resource counterpart is likely to be a key factor in future research activities. This paper presents an Exergy and Thermoeconomic analysis of a 320 MW Dual Pressure Combined Cycle Plant, aimed to identify the optimal design configurations of the system with respect to its specific objective functions: second law efficiency, economic cost and natural resource consumption cost of the generated unit of electric energy. The natural resource consumption of the system is computed according to the Cumulative Exergy Consumption (CExC) method. The CCPP plant simulations have been performed by using CAMEL-Pro™ Process Simulator and the sensitivity study of the plant behaviour and its optimization as a function of the selected parameters have been developed by using the Proper Orthogonal Decomposition procedure. Our results confirm that the optimal design configuration is strictly dependent on the considered objective function, and helps to investigate the relationship between the thermodynamics, the economics and the resource consumption of the system, thus giving a more comprehensive understanding of its performance from different perspectives.