Analyzing different peak shaving control strategies of a short-term thermal energy storage in a district heated office building

The application of a short-term thermal energy storage can be an effective approach to realize peak shaving in district heating systems. However, the centralized storage is most integrated into the system. Thermal energy storage is often not installed in district heating substations with conventional high temperatures. In addition, there is still a lack of analysis of different water temperature control strategies effects on heating power variation. The purpose of this article is to study the characteristic of different peak shaving control strategies impacts on heating power variation and assess the possibilities for peak shaving by combining short-term thermal energy storage in a district heating substation in Finland. A 5 m³ hot water storage tank was installed to deliver heat to a Finnish office building. Dynamic simulation software IDA ICE was employed to establish and simulate the substation with the stratified tank and the building. District heating supply water was used to charge the water tank directly for supplying heat. The control strategies were designed to control the storage tank temperature. Different control strategies effects were analyzed, and the results also indicate that it reduced the daily heating peak power from 125.2 kW to 85.7 kW during the heating season.