Influence of the Operating Regime on the Performances of Thermal Solar Systems Integrated in Heating Networks

Abstract

The energy performances of the integrated thermal solar systems in the hybrid heating systems are influenced by several aspects like technology used and the way the collectors are placed, the type and technology of the heating storage, the operating temperatures in the hybrid system and last, but not least, the chosen control strategy. The operating regime of the thermal solar system characterized mainly by the thermal solar agent’s temperature and flow rate, as well as the corresponding control strategy, define the parametric framework of the system and impose its energy performances during operation. The optimized systemic variation of the temperatures and flow rates in both, the solar loop and the heating circuit, results in higher annual energy performances of the hybrid heating system. The present paper approaches the premises referring to the different operating regimes that characterize thermal solar systems in order to highlight and quantify their influence over the energy performances of the thermal system. In this respect, a set of computational operating simulations were carried out on the targeted system during one year of operation, in different configurations and operating regimes, for the energy assesment of the thermal system.