Local district heating network with a small-scale trigeneration plant: Energetic and economic analysis of optimization strategies

District heating networks, integrated with cogeneration plants, allow primary energy savings to be obtained compared to traditional heat-generation systems. However, the management of these plants in residential applications is a complex issue, because of the fluctuations in the thermal users’ daily profiles. The proper operation of these plants therefore becomes of utmost importance in order to avoid energy dissipations and with a consequent economic profitability loss. The paper has the aim of illustrating the experimental data of a real, local district heating network coupled to a trigeneration plant installed and in operation in Turin, Italy. The main technical characteristics of the installation are described, and the present operational strategies are presented and discussed. The study focuses on the analysis of several possible optimizations of these strategies, and the increase in energy efficiency that can be obtained for each of them, taking into account the thermal losses over the heating grid. A comparative economic analysis has also been carried out in order to highlight the effect of these optimizations on the economic profitability of the installation. The results of the study are presented in detail and discussed in the paper