An alternative tool for the energy evaluation and the management of thermal networks: The exergy analysis

In the context of the strategy “Europe 2020”, European Directive 2012/27 identifies the high efficiency cogeneration and the district heating and cooling as instruments to reach the energy efficiency goals. The great potential deriving from these solutions is basically linked to the possible use of Renewable Energy Sources (RES) rarely used in centralized energy production. In literature many energy, economic or environmental indexes for the evaluation of energy networks efficiency are available. Notwithstanding, these indexes, based on primary energy savings, are less reliable when generation system powered by RES are analyzed. The goal of this work is the introduction of exergy as an alternative evaluation tool for the characterization of the thermal energy networks efficiency. In this research a parametric analysis has been carried out based on a Simulink [1] model. This model simulates the dynamic behavior of an energy micro-grid dedicated to three different buildings. The simulations have been run for three cities located in different climatic zones. Results show the positive impact of exergy as a tool to evaluate energy networks powered by traditional and renewable energy sources.