Load-shifting strategies in district heating networks with constant supply temperature: the case study of Verona

Abstract

District heating and cooling networks are a key infrastructure to decarbonise the heating and cooling sector. Besides the design of new networks according to the principles of the 4th and 5th generation district heating, operational aspects may significantly contribute to improve the efficiency of existing networks from both economic and environmental standpoints. In the present work, computer simulations using a district heating network model (NeMo) were carried out to investigate the load shifting potential offered by the thermal capacitance of the water volume enclosed in the network pipelines. The average return temperature is increased before the occurrence of the peak load by adjusting the flow rate according to the forecasted heat demand for the upcoming hours. The effectiveness of this control strategy was demonstrated for the district heating network of Verona, proving that the peak load can be significantly reduced, especially during middle season. Finally, the load shifting strategy was used to allow a change in the heat production mix, thereby reducing the primary energy consumption of the main heat supply station during the considered period.