Quantifying flexibility potential on district heating local thermal substations

The current work investigates an integrated framework for evaluating DHN substation flexibility, which is commonly known to depend on thermal mass and controlling strategies. However, while it is already acknowledged that thermal comfort is a subjective and dynamic parameter, the present literature has not stressed out its contribution to DHN flexibility. Therefore, the aim of this study is to enrich the present flexibility potential evaluation methods, by considering three parameters for the evaluation of the substation flexibility potential: thermal mass, controlling strategies and thermal comfort settings. In this work the maximum thermal flexibility potential is set as the maximum thermal power reduction that the consumer can tolerate, without compromising thermal comfort. The building is simulated in multiparametric two-day simulation scenarios, where the thermal power cutoff event takes place during the second day. The current work has uncovered that by reducing the thermal comfort zone by 2 degrees C, the maximum power reduction increased from 15% to 17% for light buildings, and from 30% to 40% in heavy cases. Moreover, while implementing preheating controlling strategies lead to up to 60% maximum power reduction, considering the thermal comfort zone of the consumer could further increase the flexibility potential to 75% reduction and reduce preheating times. The methodology that emerges from this work could be used to increase the real-time adaptivity of DHN decision support systems based on evaluation, enhancement and exploitation of thermal network flexibility, as well as establish a bidirectional exchange of information between energy consumers and producers of the grid.& COPY; 2023 Elsevier Ltd. All rights reserved.